Soviet and Russian solar heat supply - scientific and engineering schools. Solar heating of a private house: options and device diagrams Classification and main elements of solar systems

With the rise in energy prices, the use of alternative energy sources is becoming increasingly important. And since heating is the main item of expenses for many, then we are talking about heating in the first place: you have to pay practically all year round and considerable sums. If you want to save money, the first thing that comes to mind is solar heat: a powerful and completely free source of energy. And it's quite possible to use it. Moreover, the equipment is expensive, but several times cheaper than heat pumps. Let's talk in more detail about how the sun's energy can be used to heat a house.

Heating from the sun: pros and cons

If we talk about using solar energy for heating, then you need to keep in mind that there are two different devices for converting solar energy:

Both options have their own characteristics. Although you must immediately say which of them you choose, do not rush to give up the heating system that you have. The sun rises, of course, every morning, but not always on your Solar cells will get enough light. The smartest solution is to make a combined system. When there is enough energy from the sun, the second heat source will not work. With this you will protect yourself, and you will live in comfortable conditions, and save money.

If there is no desire or opportunity to install two systems, your solar heating should have at least a double power reserve. Then you can definitely say that you will have warmth in any case.

Benefits of using solar energy for heating:

Disadvantages:

• Dependence of the amount of incoming heat on the weather and the region.
• Guaranteed heating requires a system that can work in parallel with a solar heating system. Many manufacturers of heating equipment provide for this option. In particular, European manufacturers of wall-mounted gas boilers provide for joint operation with solar heating (for example, Baxi boilers). Even if you have installed equipment that does not have such an opportunity, you can coordinate the operation of the heating system using the controller.
• Solid financial investments at the starting point.
• Periodic maintenance: Tubes and panels should be cleaned of adhering debris and washed from dust.
• Some of the liquid solar collectors cannot operate at very low temperatures. On the eve of severe frosts, the liquid must be drained. But this does not apply to all models and not all fluids.

Now let's take a closer look at each of the types of solar heating elements.

Solar collectors

It is solar collectors that are used for solar heating. These installations use the heat of the sun to heat a heating fluid, which can then be used in a hot water heating system. The specificity is that a solar water heater for heating a house produces only a temperature of 45-60 ° C, and shows the highest efficiency at 35 ° C at the outlet. Therefore, such systems are recommended for use in tandem with warm water floors. If you do not want to give up radiators, either increase the number of sections (approximately two times) or warm up the coolant.

Solar collectors (flat and tubular) can be used to provide the house with warm water and for hot water heating.

Now about the types of solar collectors. Structurally, there are two modifications:

• flat;
• tubular.

In each of the groups there are variations in both materials and design, but they have the same principle of operation: a coolant runs through the tubes, which heats up from the sun. But the designs are completely different.

Flat solar collectors

These solar heating systems have simple design and therefore it is them that can be made with your own hands if you wish. A solid bottom is fixed to the metal frame. A layer of thermal insulation is laid on top. Insulated to reduce losses and housing walls. Then comes the layer of adsorber - a material that absorbs solar radiation well, converting it into heat. This layer is usually black. Pipes are fixed on the adsorber through which the coolant flows. From above, this whole structure is closed with a transparent lid. The material for the cover can be tempered glass or one of the plastics (most often polycarbonate). On some models, the light-transmitting material of the cover may pass through special processing: To reduce reflectivity, it is not made smooth, but slightly matte.

The pipes in a flat solar collector are usually arranged in a snake, there are two holes - an inlet and an outlet. One-pipe and two-pipe connection can be realized. This is as you like. But a pump is needed for normal heat exchange. A gravity system is also possible, but it will be very ineffective due to the low speed of movement of the coolant. It is this type of solar collector that is used for heating, although it can be used to efficiently heat water for hot water supply.

There is a variant of a gravity collector, but it is used mainly for heating water. This design is also called a plastic solar collector. These are two transparent plastic plates sealed to the body. Inside there is a labyrinth for the movement of water. Sometimes the bottom panel is painted black. There are two openings - inlet and outlet. The water is supplied inside, as it moves through the labyrinth, it is warmed by the sun, and comes out already warm. This scheme works well with a water tank and easily heats the hot water supply. It is a modern replacement for the conventional barrel mounted on a summer shower. Moreover, it is a more effective replacement.

How efficient are solar collectors? Among all household solar installations today they show the best results: their efficiency is 72-75%. But not everything is so good:

• they do not work at night and do not work well in cloudy weather;
• large heat losses, especially with wind;
• low maintainability: if something breaks down, then a significant part, or the entire panel, needs to be replaced.

Nevertheless, heating of a private house from the sun is often done with the help of these solar installations. Such installations are popular in southern countries with active radiation and positive temperatures in winter. They are not suitable for our winters, but in summer season show good results.

Air collector

This setting can be used to air heating at home. Structurally, it is very similar to the plastic collector described above, but air circulates and heats up in it. Such devices are hung on the walls. They can work in two ways: if the solar air heater is hermetically sealed, air is taken from the room, heats up and returns to the same room.

There is another option. It combines heating with ventilation. There are holes in the outer casing of the air manifold. Through them, cold air enters the structure. Passing through the labyrinth, it heats up from the sun's rays, and then warmed up enters the room.

Such heating of the house will be more or less effective if the installation occupies the entire southern wall, and there will be no shadow on this wall.

Tubular collectors

Here, too, the coolant circulates through the pipes, but each of these heat exchange pipes is inserted into a glass flask. They all come together in a manifold, which is essentially a comb.

Scheme of a tubular collector (click to enlarge the picture)

Tubular collectors have two types of tubes: coaxial and feather. Coaxial - pipe in pipe - are nested one into the other and their edges are sealed. A rarefied airless environment is created between the two walls. Therefore, such tubes are also called vacuum tubes. Feather tubes are a regular tube that is sealed on one side. And they are called feathers because to increase heat transfer, an adsorber plate is inserted into them, which has curved edges and is somewhat reminiscent of a feather.

In addition, different types of heat exchangers can be inserted into different housings. The first are Heat-pipe thermal channels. This is a whole system for converting sunlight into thermal energy... Heat-pipe is a small diameter hollow copper tube that is soldered at one end. The second has a massive tip. The tube is filled with a substance with a low boiling point. When heated, the substance begins to boil, part of it turns into a gaseous state and rises up the tube. On the way from the heated tube walls, it heats up more and more. It gets to the top, where it stays for a while. During this time, the gas transfers part of the heat to the massive tip, gradually cools, condenses and settles down, where the process is repeated again.

The second way - U-type - is a traditional tube filled with a coolant. No news or surprises here. Everything is as usual: from one side the coolant enters, passing through the tube, heats up from the sunlight. Despite its simplicity, this type of heat exchanger is more efficient. But it is used less often. This is because solar water heaters of this type form a single whole. If one tube is damaged, the entire section has to be replaced.

Tubular collectors with the Heat-pipe system are more expensive, show less efficiency, but are used more often. And all because a damaged tube can be changed in a couple of minutes. Moreover, if a coaxial flask is used, then the tube can also be repaired. It is simply disassembled (the top cap is removed) and the damaged element (the heat channel or the bulb itself) is replaced with a serviceable one. Then the tube is inserted into place.

Which collector is better for heating

For southern regions with mild winters and a lot of sunny days a year the best way- flat collector. In this climate, it shows the highest productivity.

For regions with more severe climates, tubular collectors are suitable. Moreover, systems with Heat-pipe are more suitable for harsh winters: they warm even at night and even in cloudy weather, collecting most of the solar radiation spectrum. They are not afraid of low temperatures, but the exact temperature range needs to be clarified: it depends on the substance in the heat channel.

These systems, if properly calculated, can be basic, but more often they simply save heating costs from another, paid source of energy.

Another auxiliary heating can be an air manifold. It can be made in the entire wall, and it is easy to do it yourself. It is perfect for heating a garage or summer cottage. Moreover, problems with insufficient heating may arise not in winter, as you expect, but in autumn. In frost and snow, the sun's energy is many times greater than in cloudy rainy weather.

Solar panels

Hearing the word "solar energy" we primarily think about batteries, which convert light into electricity. And this is done by special photoelectric converters. They are commercially available from a variety of semiconductors. Most often, we use silicon solar cells for domestic use. They have the lowest price and show a fairly decent performance: 20-25%.

Solar panels for a private house are common in some countries

You can directly use solar panels for heating only if you connect a boiler or other electric heating device to this power source. Also, solar panels in conjunction with electric batteries can be integrated into the home's electricity supply system and thus reduce monthly bills for used electricity. In principle, it is quite realistic to fully meet the needs of the family from these attitudes. It just takes a lot of funds and space. On average, 120-150W can be obtained from a square meter of the panel. So count how many squares of the roof or adjoining territory should be occupied by such panels.

Features of solar heating

The feasibility of installing a solar heating system is questionable for many. The main reason is it's expensive and will never pay for itself. With the fact that it is expensive, we have to agree: the prices for the equipment are rather big. But no one is stopping you from starting small. For example, to assess the effectiveness and practicality of an idea, make a similar installation yourself. Costs are minimal, and you will have a first-hand idea. Then you will decide whether to deal with all this or not. Here's just the thing: all the negative messages from theorists. Not a single one was encountered from practitioners. There is an active search for ways to improve, rework, but no one said that the idea was useless. It says something.

Now that installing a solar heating system will never pay off. As long as the payback period

bridges in our country are large. It is comparable to the lifespan of solar collectors or batteries. But if we look at the dynamics of the growth of prices for all energy resources, we can assume that soon it will be reduced to quite acceptable terms.

Now, actually about how to make a system. First of all, you need to determine the need of your house and seven for heat and hot water. The general method for calculating a solar heating system is as follows:

• Knowing in which region the house is located, you can find out how much sunlight falls on 1m 2 of the area in each month of the year. Experts call this insolation. Based on this data, you can then estimate how many solar panels you need. But first you need to determine how much heat will be needed for the preparation of hot water supply and heating.
• If you have a hot water meter, then you know the amount of hot water that you spend on a monthly basis. Print the average consumption data for a month or count according to the maximum consumption - whoever wants it. You should also have data on heat loss at home.
• Have a look at the solar heaters you would like to supply. Having data on their performance, you can roughly determine the number of elements required to cover your needs.

In addition to determining the number of components of the solar system, it will be necessary to determine the volume of the tank in which hot water for hot water supply will accumulate. This can be done easily by knowing your family's actual expense. If you have a DHW meter installed and you have data for several years, you can display the average daily consumption rate (average monthly consumption divided by the number of days). This is approximately the volume of the tank you need. But the tank needs to be taken with a margin of 20% or so. Just in case.

If there is no hot water supply or a meter, you can use the consumption rates. One person consumes on average 100-150 liters of water per day. Knowing how many people permanently live in the house, you will calculate the required volume of the tank: the rate is multiplied by the number of residents.

It must be said right away that the rational (in terms of payback) for middle lane Russia has a solar heating system that covers about 30% of heat demand and fully supplies hot water. This is an average result: in some months heating will be provided by 70-80% by the solar system, and in some months (December-January) by only 10%. And again, a lot depends on the type of solar panels and the region of residence.

And it’s not just “north” or “south”. It's about the number of sunny days. For example, in very cold Chukotka, solar heating will be very effective: the sun is almost always shining there. In the much milder climate of England, with eternal fogs, its effectiveness is extremely low.
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Outcomes

Despite many critics who talk about the inefficiency of solar energy and too long a payback period, more and more people are at least partially switching to alternative sources... In addition to savings, many are attracted by independence from the state and its pricing policy. In order not to regret the money invested in vain, you can first conduct an experiment: make one of the solar installations with your own hands and decide for yourself how much it attracts you (or not).

What are solar thermal collectors used for? Where you can use them - applications, applications, pros and cons of collectors, specifications, efficiency. Is it possible to do it yourself and how justified is it. Application schemes and perspectives.

Appointment

The collector and solar panel are two different devices. The battery uses the conversion of solar energy into electrical energy, accumulated in batteries and used for domestic needs. Solar collectors, like a heat pump, are designed to collect and store environmentally friendly energy from the Sun, the transformation of which is used to heat water or heating. On an industrial scale, solar thermal power plants have become widely used, converting heat into electricity.

Device

Collectors are made up of three main parts:

• panels;
• avancamera;
• storage tank.

The panels are presented in the form of a tubular radiator placed in a box with an outer glass wall. They must be placed in any well-lit place. Liquid enters the panel radiator, which then heats up and moves to the front chamber, where cold water is replaced by hot water, which creates constant dynamic pressure in the system. In this case, the cold liquid enters the radiator, and the hot one enters the storage tank.

Standard panels are easy to adapt to any conditions. With the help of special mounting profiles, they can be installed parallel to each other in a row in an unlimited number. Holes are drilled in aluminum mounting profiles and fixed to the panels from below with bolts or rivets. After the completion of the work, the solar absorber panels together with the mounting profiles form a single rigid structure.

The solar heating system is divided into two groups: with air and with liquid heat carrier. Collectors capture and absorb radiation, and, converting it into thermal energy, transfer it to the storage element, from which the heat is distributed throughout the room. Any of the systems can be supplemented with auxiliary equipment (circulation pump, pressure sensors, safety valves).

Principle of operation

In the daytime, thermal radiation is transferred to the coolant (water or antifreeze) circulating through the collector. The heated coolant transfers energy to the water heater tank, located above it and collecting water for hot water supply. In the simple version, the circulation of water is carried out in a natural way due to the difference in density of hot and cold water in the circuit, and in order to ensure that the circulation does not stop, a special pump is used. The circulation pump is designed for active pumping of liquid along the structure.


In a sophisticated version, the collector is included in a separate circuit filled with water or antifreeze. The pump helps them begin to circulate, while transferring the stored solar energy into a thermally insulated storage tank, which allows you to store heat and take it when needed. If the energy is insufficient, the electrical or gas heater, automatically turns on and maintains the required temperature.

Views

Those who want a solar heating system in their home should first decide on the most suitable type collector.

Flat collector

It is presented in the form of a box, covered with tempered glass, and has a special layer that absorbs solar heat. This layer is connected to pipes through which the coolant circulates. The more energy it receives, the higher its efficiency. Reducing heat losses in the panel itself and ensuring the greatest heat absorption on the absorber plates allows for maximum energy collection. In the absence of stagnation, flat collectors are capable of heating water up to 200 ° C. They are designed for heating water in swimming pools, domestic needs and heating the house.

Vacuum manifold

It is a glass battery (a row of hollow tubes). The outer battery has a transparent surface, while the inner battery is coated with a special layer that traps radiation. The vacuum interlayer between the internal and external batteries helps to conserve about 90% of the absorbed energy. Heat conductors are special tubes. When the panel heats up, the liquid at the bottom of the battery is converted into steam, which rises and transfers heat to the collector. This type of system is more efficient than flat collectors as it can be used at low temperatures and in low light conditions. A solar vacuum battery allows you to heat the temperature of the coolant up to 300 ° C, using a multilayer glass coating and creating a vacuum in the collectors.

Heat pump

Solar heating systems work most efficiently with a device such as a heat pump. Designed to collect energy from the environment regardless of weather conditions and can be installed inside the house. The source of energy here can be water, air or soil. The heat pump can be operated using only solar collectors if there is sufficient solar power. When using a combined system "heat pump and solar collector", the type of collector does not matter, but the most suitable option would be a solar vacuum battery.

What's better

The solar heating system can be installed on any kind of roof. Flat collectors are considered more durable and reliable, in contrast to vacuum ones, the design of which is more fragile. However, if the flat collector is damaged, the entire absorbent system will have to be replaced, whereas in the case of a vacuum only the damaged battery will have to be replaced.


The efficiency of a vacuum manifold is much higher than that of a flat one. They can be used in winter time and they produce more energy in cloudy weather. The heat pump has become quite widespread, despite its high cost. The energy production rate of vacuum collectors depends on the size of the tubes. Normally, the dimensions of the tubes should be 58 mm in diameter with a length of 1.2-2.1 meters. It is quite difficult to install the collector with your own hands. However, possession of certain knowledge, as well as following the detailed instructions for installation and selection of the location of the system, indicated when purchasing the equipment, will greatly simplify the task and help bring solar heat into the house.

2018-08-15

In the USSR, there were several scientific and engineering schools of solar heat supply: Moscow (ENIN, IVTAN, MEI, etc.), Kiev (KievZNIIEPIO, Kiev Civil Engineering Institute, Institute of Technical Thermophysics, etc.), Tashkent (Physics and Technology Institute of the Academy of Sciences of the Uzbek SSR, TashZNIIEP), Ashgabat (Institute of Solar Energy of the Academy of Sciences of the TSSR), Tbilisi ("Spetshelioteplomontazh"). In the 1990s, specialists from Krasnodar, the defense complex (the city of Reutov in the Moscow Region and Kovrov), the Institute of Marine Technologies (Vladivostok), and Rostovteploelektroproekt joined in this work. The original school of solar power plants was created in Ulan-Uda by G.P. Kasatkin.

Solar heating is one of the world's most advanced solar energy conversion technologies for heating, hot water and cooling. In 2016, the total capacity of solar heating systems in the world was 435.9 GW (622.7 million m²). In Russia, solar heat supply has not yet received widespread practical use, which is primarily associated with relatively low tariffs for heat and electrical energy... In the same year in our country, according to expert data, only about 25 thousand square meters of solar power plants were in operation. In fig. 1 shows a photograph of the largest solar plant in Russia in the city of Narimanov, Astrakhan Region, with an area of ​​4400 m².

Taking into account the global trends in the development of renewable energy, the development of solar heat supply in Russia requires an understanding of domestic experience. It is interesting to note that the questions of the practical use of solar energy in the USSR at the state level were discussed in 1949 at the First All-Union Meeting on Solar Engineering in Moscow. Particular attention was paid to active and passive solar heating systems in buildings.

The active system project was developed and implemented in 1920 by physicist V.A.Mikhelson. In the 1930s, passive solar heating systems were developed by one of the initiators of solar technology - engineer-architect Boris Konstantinovich Bodashko (city of Leningrad). In the same years, Doctor of Technical Sciences, Professor Boris Petrovich Veinberg (Leningrad) conducted research on solar energy resources in the USSR and developed theoretical foundations construction of solar power plants.

In 1930-1932 KG Trofimov (Tashkent city) developed and tested a solar air heater with a heating temperature of up to 225 ° C. One of the leaders in the development of solar collectors and solar hot water systems (DHW) was Ph.D. Boris Valentinovich Petukhov. In the book "Solar water heaters of tubular type" published by him in 1949, he substantiated the feasibility of development and the main Constructive decisions flat solar collectors (SC). Based on ten years of experience (1938-1949) in the construction of solar plants for hot water supply systems, he developed a methodology for their design, construction and operation. Thus, already in the first half of the last century, research was carried out in our country on all types of solar heat supply systems, including the potential and methods for calculating solar radiation, liquid and air solar collectors, solar installations for hot water supply systems, active and passive solar heating systems. ...

In most areas, Soviet research and development in the field of solar heat supply occupied a leading position in the world. At the same time, it did not receive wide practical application in the USSR and developed on an initiative basis. So, Ph.D. B.V. Petukhov has designed and built dozens of solar thermal power plants own design at the border posts of the USSR.

In the 1980s, following foreign developments initiated by the so-called "world energy crisis", domestic developments in the field of solar energy became much more active. The initiator of new developments was the Energy Institute. G. M. Krzhizhanovsky in Moscow (ENIN), which has accumulated experience in this area since 1949.

The Chairman of the State Committee for Science and Technology, Academician V.A.Kirillin, visited a number of European scientific centers that began extensive research and development in the field of renewable energy, and in 1975, in accordance with his instructions, the Institute was involved in work in this direction. high temperatures Academy of Sciences of the USSR in Moscow (now the Joint Institute for High Temperatures, JIHT RAS).

In the 1980s, the Moscow Power Engineering Institute (MEI), the Moscow Civil Engineering Institute (MISS), and the All-Union Institute of Light Alloys (VILS, Moscow) began to engage in research in the field of solar heat supply in the 1980s.

The development of experimental projects for high-power solar plants was carried out by the Central Research and Design Institute for Experimental Design (TsNII EPIO, Moscow).

The second most important scientific and engineering center for the development of solar heat supply was Kiev (Ukraine). The leading organization in the Soviet Union for the design of solar power plants for housing communal services Gosgrazhdanstroy of the USSR determined the Kiev Zonal Research and Design Institute (KievZNIIEP). Research in this direction was carried out by the Kiev Engineering and Construction Institute, the Institute of Technical Thermophysics of the Academy of Sciences of Ukraine, the Institute for Problems of Materials Science of the Academy of Sciences of the Ukrainian SSR and the Kiev Institute of Electrodynamics.

The third center in the USSR was the city of Tashkent, where the Physico-Technical Institute of the Academy of Sciences of the Uzbek SSR and the Karshi State Pedagogical Institute were engaged in research. The development of projects for solar power plants was carried out by the Tashkent Zonal Research and Design Institute TashZNIIEP. V Soviet time solar heat supply was handled by the Institute of Solar Energy of the Academy of Sciences of the Turkmen SSR in the city of Ashgabat. In Georgia, studies of solar collectors and solar plants were carried out by the association "Spetshelioteplomontazh" (Tbilisi) and the Georgian Research Institute of Energy and Hydraulic Structures.

In the 1990s in Russian Federation specialists from the city of Krasnodar, the defense complex (AO VPK NPO Mashinostroeniya, Kovrov Mechanical Plant), the Institute of Marine Technologies (Vladivostok), Rostovteploelektroproekt, and the Sochi Institute of Balneology have joined in the research and design of solar power plants. A brief overview of scientific concepts and engineering developments is presented in the work.

In the USSR, the head scientific organization for solar heat supply was the Energy Institute (ENIN *, Moscow) ( approx. author: The activity of ENIN in the field of solar heat supply is fully described by Doctor of Technical Sciences, Professor Boris Vladimirovich Tarnizhevsky (1930-2008) in the article "Solar Circle" from the collection "ENIN. Memories of the oldest employees "(2000).), which was organized in 1930 and headed until the 1950s by the leader of the Soviet power industry, a personal friend of V.I. Lenin - Gleb Maksimilianovich Krzhizhanovsky (1872-1959).

In the ENIN, on the initiative of G.M.Krzhizhanovsky, a laboratory of solar engineering was created in the 1940s, which was headed at first by Doctor of Technical Sciences, Professor F.F.Molero, and then for many years (until 1964) by Doctor of Technical Sciences ., Professor Valentin Alekseevich Baum (1904-1985), combining the duties of the head of the laboratory with the work of the deputy director of ENIN.

VA Baum immediately grasped the essence of the matter and gave important advice for graduate students on the continuation or completion of the work. His students recalled the laboratory seminars with gratitude. They were very interesting and at a really good level. VA Baum was a very widely erudite scientist, a man of high culture, great sensitivity and tact. He retained all these qualities to a ripe old age, using the love and respect of his students. High professionalism, scientific approach and decency distinguished this extraordinary person. More than 100 candidate and doctoral dissertations were prepared under his supervision.

Since 1956 B.V. Tarnizhevsky (1930-2008) is a postgraduate student of V.A. Baum and a worthy successor of his ideas. High professionalism, scientific approach and decency distinguished this extraordinary person. Among dozens of his students is the author of this article. In ENIN B.V. Tarnizhevsky worked until the last days of his life for 39 years. In 1962, he went to work at the All-Russian Research Institute of Power Sources, located in Moscow, and then, 13 years later, returned to ENIN.

In 1964, after VA Baum was elected a full member of the Academy of Sciences of the Turkmen SSR, he left for Ashgabat, where he headed the Physicotechnical Institute. Yuri Nikolaevich Malevsky (1932-1980) became his successor as the head of the laboratory of solar technology. In the 1970s, he put forward the idea of ​​creating in the Soviet Union an experimental solar power plant with a capacity of 5 MW of a tower type with a thermodynamic conversion cycle (SES-5, located in the Crimea) and led a large-scale team of 15 organizations for its development and construction.

Another idea of ​​Yu. N. Malevsky was to create a complex experimental base for solar heat and cold supply on the southern coast of Crimea, which would at the same time be a fairly large demonstration object and a research center in this area. To solve this problem, B.V. Tarnizhevsky returned in 1976 to ENIN. At this time, the solar laboratory had 70 people. In 1980, after the death of Yu.N. Malevsky, the laboratory of solar technology was divided into a laboratory of solar power plants (headed by V.A. B.V. Tarnizhevsky, who was engaged in the creation of the Crimean base of heat and cold supply. Before joining ENIN, I.V. Baum was in charge of a laboratory at the NPO "Sun" of the Academy of Sciences of the Turkmen SSR (1973-1983) in Ashgabat.

In ENIN, I.V. Baum was in charge of the SES laboratory. In the period from 1983 to 1987, he did a lot to create the first thermodynamic solar power plant in the USSR. In the 1980s, work on the use of renewable energy sources and, first of all, solar energy reached the greatest turnaround at the institute. In 1987, the construction of the Crimean experimental base in the Alushta region was completed. For its operation, a special laboratory was created on site.

In the 1980s, the solar heat supply laboratory took part in the implementation of solar collectors in mass industrial production, the creation of solar and hot water supply installations, including large ones with an area of ​​\ u200b \ u200bc over 1000 m2, and other large-scale projects.

As B. V. Tarnizhevsky recalled, in the field of solar heat supply in the 1980s, the activities of Sergei Iosifovich Smirnov were irreplaceable, who participated in the creation of the country's first solar-fuel boiler house for one of the hotels in Simferopol, a number of other solar installations, in the development of design techniques for the design of solar heating installations. SI Smirnov was a very noticeable and popular person at the institute.

Powerful intellect combined with kindness and some impulsiveness of character created a unique charm of this person. Yu. L. Myshko, BM Levinsky and other collaborators worked with him in his group. The Selective Coating Development Group, headed by Galina Aleksandrovna Gukhman, developed a technology for the chemical deposition of selective absorbing coatings on absorbers of solar collectors, as well as a technology for applying a heat-resistant selective coating on tubular receivers of concentrated solar radiation.

In the early 1990s, the Solar Heating Laboratory provided scientific and organizational leadership for a new generation solar collector project that was part of the Sustainable Energy Program. By 1993-1994, as a result of research and development work, it was possible to create designs and organize the production of solar collectors that are not inferior to foreign counterparts in terms of thermal and operational characteristics.

Under the leadership of B. V. Tarnizhevsky, the project GOST 28310-89 “Solar collectors. General technical conditions ". To optimize the designs of flat solar collectors (PSK), Boris Vladimirovich proposed a generalized criterion: the quotient of dividing the cost of the collector by the amount of thermal energy generated by it during the estimated service life.

In recent years of the USSR, under the leadership of Doctor of Technical Sciences, Professor B.V. Tarnizhevsky, designs and technologies of eight solar collectors were developed: one with a panel absorber made of stainless steel, two with absorbers made of aluminum alloys, three with absorbers and transparent insulation polymer materials, two designs of air collectors. Technologies for growing sheet-tube aluminum profiles from a melt, a technology for making hardened glass, and applying a selective coating were developed.

The design of the solar collector, developed by ENIN, was mass-produced by the Bratsk Heating Equipment Plant. The absorber is a stamped-welded steel panel with a selective galvanic coating "black chrome". Forged body (trough) - steel, glass - window, glass seal - specialty (guerlain). Annually (according to 1989 data), the plant produced 42.3 thousand m² of collectors.

B.V. Tarnizhevsky developed methods for calculating active and passive heat supply systems for buildings. From 1990 to 2000, 26 different solar collectors were tested at the ENIN stand, including all produced in the USSR and Russia.

In 1975, the Institute of High Temperatures of the Academy of Sciences (IVTAN) under the leadership of Corresponding Member of the Russian Academy of Sciences, Doctor of Technical Sciences, Professor Ewald Emilievich Shpilrain (1926-2009) joined the work in the field of renewable energy. IVTANA's work on renewable energy is described in detail by Ph.D. O.S. Popel in the article “JIHT RAS. Results and Prospects ”from the jubilee collection of articles of the Institute in 2010. In a short time, together with design organizations, conceptual projects of "solar" houses for the south of the country were developed and substantiated, methods of mathematical modeling of solar heat supply systems were developed, the design of the first Russian scientific testing ground "Sun" on the Caspian Sea coast near the city of Makhachkala began.

At the ICT RAS, first a scientific group was created, and then a laboratory under the leadership of Oleg Sergeevich Popel, in which, together with the staff of the Special Design Bureau of the ICT RAS, along with ensuring the coordination and calculation and theoretical justification of the projects being developed, research began in the field of creating electrochemical optical selective coatings of solar collectors, the development of the so-called "solar ponds", solar heating systems in combination with heat pumps, solar drying plants, work was carried out in other directions.

One of the first practical results of the ICT RAS team was the construction of a "solar house" in the village of Merdzavan, Echmiadzin region of Armenia. This house became the first experimental energy-efficient "solar house" in the USSR, equipped with the necessary experimental diagnostic equipment, on which the chief designer of the project, M. S. Kalashyan from the Institute "Armgiproselkhoz" 100% provision of the house with hot water and coverage of the heating load at the level of more than 50%.

Another important practical result was the introduction at the Bratsk plant of heating equipment developed at the ICT RAS by M.D. this factory.

In the mid-1980s, the "Solntse" test site of the ICT RAS was put into operation in Dagestan. The landfill, located on an area of ​​about 12 hectares, included, along with laboratory buildings, a group of "solar houses" different types equipped with solar collectors and heat pumps. One of the largest solar radiation simulators in the world (at that time) was launched at the test site. The source of radiation was a powerful 70 kW xenon lamp equipped with special optical filters, which made it possible to control the radiation spectrum from transatmospheric (AM0) to terrestrial (AM1.5). The creation of the simulator made it possible to carry out accelerated tests of the resistance of various materials and paints to the effects of solar radiation, as well as tests of large-size solar collectors and photovoltaic modules.

Unfortunately, in the 1990s, due to a sharp reduction in budgetary funding for research and development, most of the projects launched by the ICT RAS in the Russian Federation had to be frozen. To maintain the direction of work in the field of renewable energy, research and development of the laboratory were reoriented to scientific cooperation with leading foreign centers. Projects were carried out under the INTAS and TASIS programs, the European Framework Program in the field of energy saving, heat pumps and solar adsorption refrigeration units, which, on the other hand, made it possible to develop scientific competencies in related fields of science and technology, to master and use modern methods of dynamic modeling of power plants (Ph.D. S. E. Frid).

On the initiative and under the leadership of O.S. Popel, together with Moscow State University (Ph.D. S.V. Kiselev), the Atlas of Solar Energy Resources in the Russian Federation was developed, and the Geographic Information System Renewable Energy Sources of Russia "(Gisre.ru). Together with the Institute "Rostovteploelektroproekt" (Ph.D. A. A. Chernyavsky), solar installations with solar collectors of the Kovrov Mechanical Plant were developed, built and tested for heating and hot water supply systems at the special astrophysical observatory of the Russian Academy of Sciences in Karachay-Cherkessia. The JIHT RAS has created the only Russian specialized thermohydraulic stand for full-scale thermal testing of solar collectors and solar plants in accordance with Russian and foreign standards, developed recommendations for the use of solar plants in various regions of the Russian Federation. More information about some of the results of research and development of the Joint Institute for High Temperatures of the Russian Academy of Sciences in the field of renewable energy can be found in the book by O.S. Popel and V. E. Fortov "Renewable Energy in the Modern World".

At the Moscow Power Engineering Institute (MPEI), the issues of solar heat supply were dealt with by Ph.D. V. I. Vissarionov, Doctor of Technical Sciences B. I. Kazandzhan and Ph.D. M.I. Valov.

V. I. Vissarionov (1939-2014) headed the department “Non-traditional renewable energy sources (in 1988-2004). Under his leadership, work was carried out on the calculation of solar energy resources, the development of solar heat supply. MI Valov together with the MPEI staff in 1983-1987 published a number of articles on the study of solar power plants. One of the most informative books is the work of M. I. Valov and B. I. Kazandzhan "Solar heat supply systems", which investigated the issues of low-potential solar installations (schematic diagrams, climatic data, characteristics of SC, designs of flat SC), calculation of energy characteristics, economic efficiency of using solar heat supply systems. Doctor of Technical Sciences BI Kazandzhan developed the design and mastered the production of the flat solar collector "Altan". A feature of this collector is that the absorber is made of an aluminum fin profile, inside which a copper tube is pressed, and cellular polycarbonate is used as a transparent insulation.

An employee of the Moscow Civil Engineering Institute (MISS), Ph.D. S. G. Bulkin developed thermoneutral solar collectors (absorbers without transparent insulation and thermal insulation of the body). A feature of the work was the supply of a coolant to them by 3-5 ° C below the ambient temperature and the possibility of using the latent heat of moisture condensation and frost formation of atmospheric air (solar absorption panels). The heat carrier heated in these panels was warmed up by a heat pump ("air-water"). A test bench with thermoneutral solar collectors and several solar plants in Moldova were built at MISS.

The All-Union Institute of Light Alloys (VILS) has developed and produced an SC with a stamped-welded aluminum absorber, a jellied polyurethane foam thermal insulation of the body. Since 1991, the production of SC was transferred to the Baku Plant for the Processing of Non-Ferrous Alloys. In 1981, VILS developed Guidelines for the design of energy-efficient buildings. In them, for the first time in the USSR, the absorber was integrated into the structure of the building, which improved the economics of using solar energy. The leaders of this direction were Ph.D. N. P. Selivanov and Ph.D. V.N.Smirnov.

The Central Scientific Research Institute of Engineering Equipment (TsNII EPIO) in Moscow developed a project according to which a solar-fuel boiler house with a capacity of 3.7 MW was built in Ashgabat, a project was developed for a solar-heat pump installation of the Privetlivy Bereg hotel in the city of Gelendzhik with an area of ​​SK 690 m². Three heat pumps are used refrigeration machines MKT 220-2-0 operating in the mode of heat pumps using the heat of sea water.

The leading organization of the USSR for the design of solar plants was the KievZNIIEP Institute, which developed 20 standard and reusable projects: a stand-alone solar hot water supply unit with natural circulation for an individual residential building; unified installation of solar hot water supply for public buildings with a capacity of 5, 7, 15, 25, 30, 70 m³ / day; units, parts and equipment of residential and public buildings of mass construction; installations of solar hot water supply of seasonal action with a productivity of 2.5; ten; thirty; 40; 50 m³ / day; technical solutions and methodological recommendations for the conversion of heating boilers into heliofuel installations.

This institute has developed dozens of experimental projects, including solar hot water supply systems for swimming pools, a solar heat pump installation for hot water supply. According to the project of KievZNIIEP, the largest in the USSR solar plant of the Kastropol boarding house (Beregovoe village, South Coast) in Crimea with an area of ​​1600 m² was built. At the pilot plant of the KievZNIIEP Institute, solar collectors were produced, the absorbers of which are made of coil-fin aluminum tubes of our own production.

Theorists of solar engineering in Ukraine were D.Sc. Mikhail Davidovich Rabinovich (born in 1948), Ph.D. Alexey Ruvimovich Firth, Ph.D. Victor Fedorovich Gershkovich (1934-2013). They were the main developers of the Solar Hot Water Design Standards and Design Guidelines. MD Rabinovich was engaged in research of solar radiation, hydraulic characteristics of SC, solar installations with natural circulation, solar heat supply systems, solar fuel boiler houses, solar installations of high power, solar systems. A.R. Firth developed the design of a simulator stand and carried out tests of the SC, investigated the regulation of hydraulic solar power plants, increasing the efficiency of solar power plants. At the Kiev Civil Engineering Institute, Ph.D. Nikolai Vasilievich Kharchenko. He formulated a systematic approach to the development of solar heat supply systems, proposed criteria for assessing their energy efficiency, investigated the optimization of a solar heat supply system, performed a comparison different methods calculation of solar systems. One of his most complete books on small (individual) solar solar installations is notable for its accessibility and informational content. At the Kiev Institute of Electrodynamics, Ph.D. A. N. Stronsky and Ph.D. A. V. Suprun. Candidate of technical sciences also worked on mathematical modeling of solar power plants in Kiev. V.A. Nikiforov.

The leader of the scientific engineering school of solar engineering in Uzbekistan (Tashkent) is Doctor of Technical Sciences, Professor Rabbanakul Rakhmanovich Avezov (born in 1942). In 1966-1967 he worked at the Ashgabat Physico-Technical Institute of Turkmenistan under the guidance of Doctor of Technical Sciences, Professor V. A. Baum. RR Avezov develops the ideas of the teacher at the Physico-Technical Institute of Uzbekistan, which has turned into an international research center.

Scientific directions of research RR Avezov formulated in his doctoral dissertation (1990, ENIN, Moscow), and its results are summarized in the monograph "Solar heating and hot water supply systems". He develops, among other things, methods of exergy analysis of flat solar collectors, creation of active and passive solar heating systems. Doctor of Technical Sciences R.R. Avezov secured great authority and international recognition to the only specialized magazine in the USSR and the CIS countries, Applied Solar Energy ("Heliotekhnika"), which is published on English language... His daughter Nilufar Rabbakumovna Avezova (born 1972) - Doctor of Technical Sciences, General Director of the Scientific and Production Association "Physics-Sun" of the Academy of Sciences of Uzbekistan.

The development of projects for solar power plants in the Tashkent zonal research institute of experimental design of residential and public buildings (TashZNIIEP) was carried out by Ph.D. Yusuf Karimovich Rashidov (born 1954). Institute "TashZNIIEP" developed ten standard projects of residential buildings, solar-powered boiler rooms, solar-fuel boiler house, including solar installations with a capacity of 500 and 100 l / day, solar-powered for two and four cabins. From 1984 to 1986, 1200 standard solar plant projects were implemented.

In the Tashkent region (Ilyichevsk settlement), a two-apartment solar house with heating and hot water supply with a solar plant with an area of ​​56 m² was built. At the Karshi State Pedagogical Institute A.T. Teymurkhanov, A.B. Vardiyashvili and others were engaged in research of flat solar collectors.

The Turkmen scientific school of solar heat supply was created by Ph.D. V. A. Baum, elected in 1964 as an academician of the republic. At the Ashgabat Institute of Physics and Technology, he organized a solar energy department and until 1980 headed the entire institute. In 1979, on the basis of the Department of Solar Energy, the Institute of Solar Energy of Turkmenistan was created, headed by V. A. Baum's student, Doctor of Technical Sciences. Recep Bayramovich Bayramov (1933-2017). In the suburb of Ashgabat (the village of Bikrova), a scientific testing ground of the institute was built, consisting of laboratories, test stands, a design bureau, workshops with a number of employees of 70 people. VA Baum until the end of his life (1985) worked at this institute. RB Bayramov together with Doctor of Technical Sciences Ushakova Alda Danilovna investigated flat solar collectors, solar heating systems and solar desalination plants. It is noteworthy that in 2014 in Ashgabat the Institute of Solar Energy of Turkmenistan - NPO "GUN" was recreated.

In the design and production association "Spetsgelioteplomontazh" (Tbilisi) and the Georgian Research Institute of Energy and Hydraulic Structures under the leadership of Dr. Sc. Nugzar Varlamovich Meladze (born in 1937), designs were developed and the serial production of solar collectors, individual solar hot water installations, solar installations and solar heat pump systems was mastered. The conditions for the payback of the construction of solar power plants in various regions of Georgia were determined; various designs solar collectors.

Solar collectors "Spetsgelioteplomontazh" had an optimal design for their time: a stamped-welded steel absorber with a paint-and-lacquer coating, a body made of aluminum profiles and galvanized steel, window glass, thermal insulation - from foam and foil roofing material.

According to N. V. Meladze, only in the Caucasus region by 1990 46.9 thousand square meters of solar collectors were installed, including 42.7% in sanatoriums and hotels, 39.2% in industrial solar installations, and agricultural facilities - 13.8%, sports facilities - 3.6%, individual installations - 0.7%.

According to the author, in Krasnodar Territory in 1988-1992, 4620 m² of Spetsgeliomontazh solar collectors were installed. The work of the SGTM was carried out in cooperation with scientists from the Georgian Research Institute of Energy and Hydraulic Structures (GruNIIEGS).

Institute "TbilZNIIEP" developed five standard designs of solar installations (SU), as well as a project of a solar heat pump installation. SGTM included a laboratory in which solar collectors and heat pumps were studied. Steel, aluminum, plastic liquid absorbers, air SCs with and without glass, SCs with concentrators, various designs of thermosyphon individual HUs were developed. As of January 1, 1989, "Spetsgeliomontazh" had built 261 HUs with a total area of ​​46 thousand square meters and 85 individual solar installations for hot water supply systems with an area of ​​339 square meters.

In fig. 2 shows a solar plant on Rashpilevskaya street in Krasnodar, which has been successfully operating for 15 years with collectors of "Spetsgelioteplomontazh" (320 pcs. With a total area of ​​260 m²).

The development of solar heat supply in the USSR and in Russia from the side of the authorities was carried out by Dr. Pavel Pavlovich Bezrukikh (born in 1936). In 1986-1992, in the position of chief specialist of the Bureau of the Council of Ministers of the USSR on the fuel and energy complex, he oversaw the serial production of solar collectors at the brotherly heating equipment plant, in Tbilisi at the Spetshelioteplomontazh association at the Baku non-ferrous alloy processing plant. On his initiative and with his direct participation, the USSR's first program for the development of renewable energy for 1987-1990 was developed.

PP Bezrukikh since 1990 took an active part in the development and implementation of the section "Non-traditional energy" of the State Scientific and Technical Program "Environmentally Safe Energy". He notes the main role scientific supervisor of the program, Doctor of Technical Sciences E. E. Shpilrain on attracting leading scientists and specialists of the USSR on renewable energy sources. From 1992 to 2004, P.P. Bezrukikh, working in the Ministry of Fuel and Energy of Russia and heading the department, and then the department of scientific and technical progress, led the organization of production of solar collectors at the Kovrov Mechanical Plant, NPO Mashinostroenie (Reutov, Moscow Region) , a complex of scientific and technical developments in solar heat supply, the implementation of the Concept for the development and use of opportunities for small and non-traditional energy in Russia. Participated in the development of the first Russian standard GOST R 51595-2000 “Solar collectors. General technical conditions "and resolving disagreements of the author of the draft GOST R Doctor of Technical Sciences. B. V. Tarnizhevsky and chief designer of the manufacturer of collectors (Kovrov Mechanical Plant) A. A. Lychagin.

In 2004-2013 at the Institute of Energy Strategy (Moscow), and then as head of the department of energy conservation and renewable sources of ENIN, P.P. Bezrukikh continues to develop, including solar heat supply.

In the Krasnodar Territory, work on the design and construction of solar power plants was started by the heat and power engineer V. A. Butuzov (born in 1949), who headed the promising development of heat supply at the Kubanteplokommunenergo production association. From 1980 to 1986, projects were developed and six solar-fuel boiler houses with a total area of ​​1532 m² were built. Over the years, constructive relations have been established with the manufacturers of the IC: Bratsk plant, "Spetsgelioteplomontazh", KievZNIIEP. Due to the lack of solar radiation data in the Soviet climatological reference books in 1986, reliable results were obtained from the meteorological stations of Krasnodar and Gelendzhik from 1977 to 1986 for the design of solar power plants.

After defending his Ph.D. thesis in 1990, work on the development of solar technology was continued by the Krasnodar Laboratory of Energy Saving and Unconventional Energy Sources of the Academy of Public Utilities (Moscow), organized by V. A. Butuzov. Several designs of flat SCs were developed and improved, as well as a stand for their full-scale tests. As a result of generalization of the experience in the design and construction of solar power plants, “ General requirements to the design of solar power plants and central heating stations in public utilities ”.

Based on the analysis of the results of processing the values ​​of total solar radiation for the conditions of Krasnodar for 14 years, and Gelendzhik - for 15 years in 2004, it was proposed new way provision of monthly values ​​of total solar radiation with the determination of their maximum and minimum values, the probability of their observation. Calculated monthly and annual values ​​of total, direct and scattered solar radiation for 54 cities and administrative centers Krasnodar Territory. It has been established that for an objective comparison of SC of various manufacturers, in addition to comparing their costs and energy characteristics obtained by the standard method on certified test benches, it is necessary to take into account the energy consumption for their manufacture and operation. The optimal cost of the SC structure is determined in the general case by the ratio of the cost of the generated heat energy and the costs of manufacturing, operation for the estimated service life. Together with the Kovrov Mechanical Plant, the design of the SC was developed and mass-produced, which had the optimal ratio of cost and energy costs for the Russian market. Projects have been developed and construction of standard solar hot water supply units with a daily capacity of 200 l to 10 m³ has been carried out. Since 1994, work on solar power plants has been continued at South Russian Energy Company JSC. From 1987 to 2003, the development and construction of 42 solar plants was carried out, and the design of 20 solar plants was completed. The results of the work of V.A. Butuzov were summarized in a doctoral dissertation defended at ENIN (Moscow).

From 2006 to 2010 LLC "Teploproektstroy" designed and built solar boiler plants low power, when installed in which the SC in the summer, the operating personnel is reduced, which reduces the payback period of solar power plants. During these years, self-draining solar power plants were developed and built, when the pumps are stopped, in which water is drained from the SC into the tanks, preventing overheating of the coolant. In 2011, a structure was created, prototypes of flat SCs were made, a test bench was developed for organizing SC production in Ulyanovsk. From 2009 to 2013, Yuzhgeoteplo JSC (Krasnodar) developed a project and built the largest solar plant in the Krasnodar Territory with an area of ​​600 m² in the city of Ust-Labinsk (Fig. 3). At the same time, studies were carried out to optimize the layout of the SC, taking into account shading, work automation, circuit solutions. A geothermal solar heat supply system with an area of ​​144 m² was developed and built in the village of Rozovoy, Krasnodar Territory. In 2014, a methodology was developed for assessing the economic payback of solar plants, depending on the intensity of solar radiation, the efficiency of the solar plant, and the unit cost of replaced thermal energy.

The long-term creative collaboration of V.A. Butuzov with Doctor of Technical Sciences, Professor of the Kuban State Agrarian University Robert A. Amerkhanov (born in 1948) was implemented in the development of theoretical foundations for the creation of high-power solar plants and combined geothermal-solar heat supply systems. Dozens of candidates of technical sciences, including those in the field of solar heat supply, have been trained under his leadership. In numerous monographs by R. A. Amerkhanov, the design issues of solar power plants for agricultural purposes are considered.

The most experienced specialist in the design of solar power plants is the chief project engineer of the Institute "Rostovteploelektroproekt" Ph.D. Adolf Alexandrovich Chernyavsky (born in 1936). He has been involved in this area on his own initiative for more than 30 years. He has developed dozens of projects, many of which have been implemented in Russia and other countries. Unique solar heating and hot water supply systems are described in the section of the Institute of the Joint Institute for High Temperatures of the Russian Academy of Sciences. A. A. Chernyavsky's projects are distinguished by the elaboration of all sections, including a detailed economic feasibility study. On the basis of solar collectors of the Kovrov Mechanical Plant, "Recommendations for the design of solar heat supply stations" were developed.

Under the leadership of A.A. Unique projects of thermodynamic solar power plants with an installed electrical capacity of 30 MW in Uzbekistan, 5 MW in the Rostov region have been completed; projects of solar installations of boarding houses on the Black Sea coast with an area of ​​40-50 m2 for solar heating systems and hot water supply of objects of a special astrophysical observatory in Karachay-Cherkessia have been implemented. The Rostovteploelektroproekt Institute is characterized by the scale of development - solar heat supply stations for residential settlements and cities. The main results of the developments of this institute, carried out jointly with the JIHT RAS, are published in the book "Autonomous power supply systems".

The development of solar installations at the Sochi State University (Institute of Resort Business and Tourism) was supervised by Doctor of Technical Sciences, Professor Pavel Vasilyevich Sadilov, Head of the Department of Environmental Engineering. An initiator of renewable energy, he designed and built several solar power plants, including in 1997 in the village of Lazarevskoye (the city of Sochi) with an area of ​​400 m², a solar power plant of the Institute of Balneology, several heat pump plants.

At the Institute of Marine Technologies of the Far Eastern Branch of the Russian Academy of Sciences (Vladivostok), the head of the laboratory of unconventional energy, Ph.D. Alexander Vasilyevich Volkov, who tragically died in 2014, designed and built dozens of solar plants with a total area of ​​2000 m², a stand for field comparative tests of solar collectors, new designs of flat SCs, and tested the efficiency of vacuum SCs from Chinese manufacturers.

An outstanding designer and person, Adolf Aleksandrovich Lychagin (1933-2012) was the author of several types of unique anti-aircraft guided missiles, including the Strela-10M. In the 1980s, in the position of chief designer (on an initiative basis) at the military Kovrov Mechanical Plant (KMZ), he developed solar collectors that were distinguished by high reliability, optimal price and energy efficiency ratio. He was able to convince the management of the plant to master the serial production of solar collectors, and to create a factory laboratory for testing the SC. From 1991 to 2011, KMZ produced about 3000 pieces. solar collectors, each of the three modifications of which was distinguished by new performance... Guided by the "power price" of the collector, at which the costs of different SC designs are compared with the same solar radiation, A. A. Lychagin created a collector with an absorber made of a brass tube grid with steel absorbing ribs. Solar air collectors have been designed and manufactured. The highest engineering qualifications and intuition were combined in Adolf Aleksandrovich with patriotism, the desire to develop environmentally friendly technologies, adherence to principles, and high artistic taste. Having suffered two heart attacks, he was able to come to Madrid specially for a thousand kilometers to study the magnificent canvases in the Prado Museum for two days.

JSC "MIC" NPO Mashinostroeniya "(Reutov, Moscow region) has been producing solar collectors since 1993. The development of designs for collectors and solar water heating plants at the enterprise is carried out by the design department of the Central Design Bureau of Mechanical Engineering. Project manager - Ph.D. Nikolay Vladimirovich Dudarev. In early solar collector designs, housings and die-welded absorbers were made of stainless steel. On the basis of a collector of 1.2 m², the company has developed and manufactured solar thermosyphon water heating units with tanks with a capacity of 80 and 120 liters. In 1994, a technology for obtaining a selective absorbing coating by the method of vacuum electric arc spraying was developed and introduced into production, which was supplemented in 1999 by the magnetron method of vacuum spraying. On the basis of this technology, the production of Sokol-type solar collectors was started. The absorber and the collector body were made of aluminum profiles. Now NPO produces solar collectors "Sokol-Effect" with sheet-tube copper and aluminum absorbers. The only Russian solar collector is certified according to European standards by the SPF Institute from Rapperswill, Switzerland (Institut für Solartechnik Hochschule für Technik Rappelswill).

Research and Production Enterprise "Competitor" (since 2000 - "Raduga-Ts", the city of Zhukovsky, Moscow region) since 1992 produced solar collectors "Raduga". Chief Designer - Vyacheslav Alekseevich Shershnev.

The die-welded absorber was made of stainless steel sheet. The absorber is coated with selective PVD or matt black heat-resistant paint. Annual program of NPP up to 4000 pcs. The energy characteristics of the reservoir were obtained during testing at ENIN. The Raduga-2M thermosyphon solar power plant was also produced, consisting of two SCs of 1 m² each and a tank with a capacity of 200 liters. The tank contained a flat heating panel, which received the coolant from the SC, as well as a backup electric heater with a capacity of 1.6 kW.

LLC "New Polyus" (Moscow) is the second Russian manufacturer that has developed its own designs and currently produces flat liquid, flat air, flat air-liquid, tubular vacuum solar collectors, carries out projects and installation of solar plants. General Director - Alexey Viktorovich Skorobatyuk.

There are four models of YSolar flat liquid collectors. All liquid absorbers from this manufacturer are made of selective Tinox coated copper sheet and copper tubing. The connection of the tubes to the sheet is brazed and welded. LLC "New Polyus" also offers three types of vacuum tube SC of its own manufacture with copper absorbers with U-shaped tubes.

An outstanding specialist, energetic and highly intellectual person Gennady Pavlovich Kasatkin (born 1941), a mining engineer and designer with many years of experience, began to engage in solar engineering in 1999 in the city of Ulan-Ude (Buryatia). In the Center for Energy Efficient Technologies (CEFT) he organized, several designs of liquid and air collectors were developed, about 100 solar plants of various types with a total area of ​​4200 m² were built. On the basis of his calculations, prototypes were made, which, after tests in full-scale conditions, were replicated on solar power plants of the Republic of Buryatia.

Engineer G.P. Kasatkin developed several new technologies: welding of plastic absorbers, manufacturing of collector bodies.

The only one in Russia, he designed and built several solar air plants with collectors of his own design. Chronologically, his solar collector development began in 1990 with welded sheet-tube steel absorbers. Then came options for copper and plastic manifolds with welded and crimp-coupled absorbers and, finally, modern designs with European copper selective sheets and tubes. G.P. Kasatkin, developing the concept of energy-active buildings, built a solar plant, the collectors of which are integrated into the roof of the building. In recent years, the engineer handed over the management functions at CEFT to his son I. G. Kasatkin, who successfully continues the traditions of CEFT LLC.

In fig. 4 shows the solar plant of the Baikal hotel in the city of Ulan-Ude with an area of ​​150 m².

conclusions

1. Calculated data of solar radiation for the design of solar power plants in the USSR were based on various methods of processing arrays of measurements of meteorological stations. In the Russian Federation, these methods are supplemented with materials from international satellite computer databases.

2. The leading school for the design of solar power plants in the Soviet Union was the KievZNIIEP Institute, which developed guidelines and dozens of projects. Currently, there are no current Russian norms and recommendations. Projects of solar installations at the modern level are carried out at the Russian institute "Rostovteploelektroproekt" (Ph.D. AA Chernyavsky) and in the company EnergotekhnologiiServis LLC (Ph.D. VV Butuzov, Krasnodar).

3. Technical and economic research of solar power plants in the USSR was carried out by ENIN (Moscow), KievZNIIEP, TsNIIEPIO (Moscow). At present, these works are being carried out at the Rostovteploelektroproekt Institute and at Energotekhnologii-Service LLC.

4. The leading scientific organization of the USSR for the study of solar collectors was the Energy Institute named after GM Krzhizhanovsky (Moscow). The best collector design for its time was produced by "Spetsgeliotepomontazh" (Tbilisi). Among Russian manufacturers, the Kovrov Mechanical Plant produced solar collectors with an optimal ratio of price and energy efficiency. Modern Russian manufacturers collectors are assembled from foreign components.

5. In the USSR, the design, manufacture of solar collectors, installation and adjustment were carried out by the company "Spetsgelioteplomontazh". Until 2010, the company CEFT LLC (Ulan-Ude) operated according to this scheme.

6. Analysis of domestic and foreign experience in solar heat supply has shown undoubted prospects for its development in Russia, as well as the need for state support. Priority measures include: creation of a Russian analogue of a solar radiation computer database; development of new designs of solar collectors with an optimal ratio of price and energy efficiency, new energy-efficient design solutions with adaptation to Russian conditions.

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The main criterion for comfort in a private cottage or apartment is warmth. In a cold house, even the chicest setting will not help create comfortable conditions... But in order for the optimal temperature for living to be maintained in the room not only in summer, but also in winter, you will need to install a heating system.

This can be done easily today by purchasing a gas, diesel or electric boiler as a heat source. But the problem is that fuel for such equipment is expensive and not available in all localities. What then to choose? The best solution are alternative heat sources and in particular solar heating.

Device and principle of operation

What is such a system? First of all, it should be said that there are two options for solar heating. They involve the use of elements that are different both in terms of design and purpose:

• Collector;
• Photovoltaic panel.

And if the equipment of the first type is designed purely to maintain a comfortable temperature in the room, then solar panels for heating a house can be used to generate electricity and heat. Their principle of operation is based on converting the energy of the sun and storing it in batteries, so that it can then be used for various needs.

We watch the video, everything about this collector:

The use of a collector allows you to organize only solar heating systems for a private house, while using thermal energy. Such a device operates as follows. The sun's rays heat the water, which is a heat carrier and comes from the pipeline. The same system can also be used as hot water supply. The composition includes special photocells.

Collector device

But besides them, the complete set of solar heating includes:

• Special tank;
• Avankamera;
• Radiator made of tubes and enclosed in a box, in which the front wall is made of glass.

Solar panels for home heating are located on the roof. In it, the water, warming up, moves to the front chamber where it is replaced by a hot coolant. This allows constant dynamic pressure to be maintained in the system.

Heating types using alternative sources

The easiest way to convert the energy of a luminary into heat is to use solar panels to heat your home. They are increasingly being used as additional energy sources. But what are these devices and are they really effective?

We watch the video, types and their features of work:

The task of the solar heating system installed on the roof of the house is to absorb as much solar radiation as possible, then converting it into energy so necessary for a person. But it should be borne in mind that it can be converted into both thermal and electrical energy. Solar heating systems are used to generate heat and heat water. Special batteries are used to generate electric current. They store energy in the daytime and release it at night. However, today there are combined systems... In them, solar panels generate heat and electricity at the same time.

As for solar water heaters for home heating, they are presented on the market with a wide range. Moreover, the models can have a different purpose, design, principle of operation, dimensions.

Various options

For example, according to appearance and the design of the heating system of a private house are divided into:

1. Flat;
2. Tubular vacuum.

By purpose, they are classified as used for:

• Heating and hot water supply systems;
• For heating the water in the pool.

There are differences in the principle of work. Solar heating with manifolds is the ideal choice for country houses, since they do not require an electrical connection. Models with forced circulation are connected to a common heating system, in which the coolant is circulated using a pump.

We watch the video, compare flat and tubular collectors:

Not all collectors are suitable for solar heating of a country house. According to this criterion, they are divided into:

• Seasonal;
• Year-round.

The former are used for heating suburban buildings, the latter in private households.

Compare with conventional heating systems

If we compare this equipment with gas or electric, then it has much more advantages. First of all, this is fuel economy. In summer, solar heating is able to fully provide people living in the house with hot water. In autumn and spring, when there are few clear days, the equipment can be used to reduce the load on a standard boiler. As for the winter season, usually at this time the efficiency of the collectors is very low.

We watch the video, the efficiency of collectors in winter:

But besides saving fuel, using solar-powered equipment reduces dependence on gas and electricity. To install solar heating, you do not need to obtain a permit and anyone who has basic knowledge of plumbing can install it.

We watch the video, the criteria for the selection of equipment:

Another plus is the long service life of the collector. The guaranteed service life of the equipment is at least 15 years, which means for this period your utility bills will be minimal.

However, like any device, the collector has some disadvantages:

• The price for solar water heaters for a private house is quite high;
• The inability to use it as the only source of heat;
• Installation of a storage tank is required.

There is one more nuance. Solar heating efficiency varies by region. In the southern regions, where solar activity is high, the equipment will have the highest efficiency. Therefore, it is most profitable to use such equipment in the south and it will be less effective in the north.

Solar collector selection and installation

Before proceeding with the installation of the equipment included in heating system it is necessary to study its possibilities. In order to find out how much heat is required to heat a house, you need to calculate its area. It is important to choose the right place for installing the solar collector. It should be as lit as possible throughout the day. Therefore, the equipment is usually installed on the southern part of the roof.

Performance installation works it is better to entrust it to specialists, because even a small mistake in the installation of a solar heating system will lead to a significant decrease in the efficiency of the system. Only when correct installation solar collector, it will last up to 25 years, and fully paid for itself in the first 3 years.

The main types of collectors and their characteristics

If the building for some reason is not suitable for the installation of equipment, then you can place the panels on the adjacent building, and put the drive in the basement.

Benefits of solar heating

The nuances that you should pay attention to when choosing this system were discussed above. And if you did everything right, then your solar heating system will bring you only pleasant moments. Among its advantages it should be noted:

• The ability to provide the house with heat all year round, with the ability to adjust the temperature;
• Full autonomy from centralized utilities and reduced financial costs;
• The use of solar energy for various needs;
• Long service life of equipment and rare emergencies.

The only thing that stops consumers from buying a solar system for heating a private house is the dependence of their work on the geography of their residence. If clear days are rare in your area, the efficiency of the equipment will be minimal.

27.09.2019

Classification and basic elements of solar systems

Solar heating systems are systems that use solar radiation as a source of thermal energy. Their characteristic difference from other low-temperature heating systems is the use of a special element - a solar receiver, designed to capture solar radiation and convert it into thermal energy.

According to the method of using solar radiation, solar low-temperature heating systems are divided into passive and active.

Passive solar heating systems are called, in which the building itself or its individual enclosures (collector building, collector wall, collector roof, Figure 1) serve as an element that perceives solar radiation and converts it into heat.

In passive solar systems, the use of solar energy is carried out exclusively through the architectural and structural solutions of buildings.

In a passive system of solar low-temperature heating, a collector building, solar radiation, penetrating through the light openings into the room, falls into a heat trap, as it were. Short-wave solar radiation freely passes through the window glass and gets on the internal fences of the room, is converted into heat. All solar radiation entering the room is converted into heat and is able to partially or completely compensate for its heat losses.

To improve the efficiency of the building-collector system, skylights large area placed on the southern facade, supplying them with blinds, which, when closed, should prevent dark time days losses with counter-radiation, and in a hot period in combination with other sun protection devices - overheating of the room. The inner surfaces are painted in dark colors.

The task of calculation for this way heating is the determination of the required area of ​​light openings for the transmission of the solar radiation flux into the room, which is necessary, taking into account the accumulation to compensate for heat losses. As a rule, the power of the passive building-collector system in cold period turns out to be insufficient, and an additional heat source is installed in the building, turning the system into a combined one. In this case, the calculation determines the economically feasible areas of the light openings and the power of the additional heat source.

Passive solar system of air low-temperature heating "wall-collector" includes a massive outer wall, in front of which, at a short distance, a radiant screen with shutters is installed. At the floor and under the ceiling, slot-like holes with valves are arranged in the wall. The sun's rays, passing through the translucent screen, are absorbed by the surface of the massive wall and converted into heat, which is transferred by convection to the air in the space between the screen and the wall. The air heats up and rises up, getting through the slot under the ceiling into the serviced room, and its place is taken by the cooled air from the room, penetrating into the space between the wall and the screen through the slot at the floor of the room. The supply of heated air to the room is controlled by opening the valve. If the valve is closed, heat accumulates in the wall mass. This heat can be removed by convective air flow, opening the valve at night or in cloudy weather.

When calculating such a passive low-temperature solar air heating system, the required wall surface area is determined. This system is also duplicated with an additional source of heat.

Active are called solar low temperature heating systems, in which the solar collector is an independent, separate device that does not belong to the building. Active solar systems can be subdivided:

• by purpose (hot water supply systems, heating systems, combined systems for heat and cold supply purposes);
• by the type of coolant used (liquid - water, antifreeze and air);
• by the duration of work (year-round, seasonal);
• according to the technical solution of the schemes (one-, two-, multi-circuit).

For active solar heating systems, two types of solar collectors are used: concentrating and flat.

Air is a widespread non-freezing coolant in the entire range of operating parameters. When using it as a heat carrier, it is possible to combine heating systems with a ventilation system. However, air is a low-heat heat carrier, which leads to an increase in metal consumption for the device of air heating systems in comparison with water systems. Water is a heat-retaining and widely available heat carrier. However, at temperatures below 0 ◦ C, it is necessary to add anti-freeze liquids to it. In addition, it must be borne in mind that water saturated with oxygen causes corrosion of pipelines and apparatus. But the consumption of metal in water solar systems is much lower, which greatly contributes to their wider application.

Seasonal solar hot water supply systems are usually single-circuit and operate in the summer and transitional months, during periods with a positive outside temperature. They can have an additional source of heat or do without it, depending on the purpose of the serviced facility and operating conditions.

The SVU solar water heating plant (Figure 2) consists of a solar collector and a heat exchanger-accumulator. A coolant (antifreeze) circulates through the solar collector. The coolant is heated in the solar collector by the energy of the Sun and then gives off thermal energy to the water through a heat exchanger mounted in the storage tank. Hot water is stored in the storage tank until it is used, so it must have good thermal insulation. In the first circuit, where the solar collector is located, natural or forced circulation of the coolant can be used. An electric or any other automatic backup heater can be installed in the storage tank. If the temperature in the storage tank drops below the set one (prolonged cloudy weather or few hours of sunshine in winter), the backup heater automatically turns on and heats up the water to the set temperature.

Solar heating systems for buildings are usually double-circuit or, most often, multi-circuit, and different heat carriers can be used for different circuits (for example, in the solar circuit - aqueous solutions of non-freezing liquids, in the intermediate circuits - water, and in the consumer circuit - air). Combined year-round solar systems for heat and cold supply of buildings are multi-circuit and include an additional heat source in the form of a traditional fossil-fueled heat generator or heat transformer. A schematic diagram of a solar heat supply system is shown in Figure 3. It includes three circulation circuits:

• the first circuit, consisting of solar collectors 1, a circulation pump 8 and a liquid heat exchanger 3;
• a second circuit consisting of a storage tank 2, a circulation pump 8 and a heat exchanger 3;
• the third circuit, consisting of a storage tank 2, a circulation pump 8, a water-air heat exchanger (air heater) 5.

The solar heating system functions as follows. The heat carrier (antifreeze) of the heat-receiving circuit, being heated in the solar collectors 1, enters the heat exchanger 3, where the heat of the antifreeze is transferred to the water circulating in the annular space of the heat exchanger 3 under the action of the pump 8 of the secondary circuit. The heated water enters the storage tank 2. From the storage tank, water is taken by the hot water supply pump 8, is brought, if necessary, to the required temperature in the backup 7 and enters the building hot water supply system. The accumulator tank is replenished from the water supply system. For heating, water from the storage tank 2 is supplied by the pump of the third circuit 8 to the heater 5, through which air is passed with the help of the fan 9 and, when heated, enters the building 4. In the absence of solar radiation or lack of heat energy generated by solar collectors, into operation turn on the backup 6. The choice and arrangement of solar heat supply system elements in each specific case are determined by climatic factors, the purpose of the facility, heat consumption mode, economic indicators.

Figure 4 shows a diagram of a solar heating system for an energy efficient eco-friendly home.

The system uses as a heat carrier: water at positive temperatures and antifreeze during the heating period (solar circuit), water (second underfloor heating circuit) and air (third solar air heating circuit).

An electric boiler was used as a backup source, and a 5 m 3 battery with a pebble attachment was used to accumulate heat for one day. One cubic meter of pebbles accumulates on average 5 MJ of heat per day.

Low-temperature heat storage systems cover the temperature range from 30 to 100 ◦C and are used in air (30 ◦ C) and hot water (30–90 ◦ C) heating and hot water systems (45–60 ◦ C).

The heat storage system, as a rule, contains a reservoir, heat storage material, with the help of which heat energy is accumulated and stored, heat exchange devices for the supply and removal of heat during charging and discharging of the battery, and thermal insulation.

Batteries can be classified according to the nature of the physicochemical processes occurring in heat storage materials:

1. capacitive batteries, in which the heat capacity of the heated material is used (pebbles, water, aqueous solutions of salts, etc.);
2. phase transition accumulators of a substance, in which the heat of fusion (solidification) of a substance is used;
3. energy accumulators based on the release and absorption of heat during reversible chemical and photochemical reactions.

The most widely used heat accumulators are of the capacitive type.

The amount of heat Q (kJ) that can be accumulated in a capacitive-type heat accumulator is determined by the formula

The most effective heat storage material in liquid solar heating systems is water. For seasonal heat accumulation, it is promising to use underground reservoirs, rock soil and other natural formations.

Concentrating solar collectors are spherical or parabolic mirrors (Figure 5.), made of polished metal, in the focus of which a heat-receiving element (solar boiler) is placed, through which the coolant circulates. Water or non-freezing liquids are used as a heat carrier. When using water as a heat carrier at night and during a cold period, the system must be emptied to prevent it from freezing.

To ensure high efficiency of the process of capturing and converting solar radiation, the concentrating solar receiver must be constantly pointed strictly at the Sun. For this purpose, the solar receiver is equipped with a tracking system that includes a sun direction sensor, an electronic signal conversion unit, an electric motor with a gearbox for rotating the solar receiver structure in two planes.

The advantage of systems with concentrating solar collectors is the ability to generate heat with a relatively high temperature (up to 100 ◦ C) and even steam. The disadvantages include the high cost of the structure; the need for constant cleaning of reflective surfaces from dust; work only during daylight hours, and therefore the need for large batteries; large energy consumption for the drive of the solar tracking system, commensurate with the generated energy. These disadvantages restrain the widespread use of active low-temperature solar heating systems with concentrating solar collectors. Recently, flat solar collectors are most often used for solar low-temperature heating systems.

Flat solar collectors

A flat plate solar collector is a heat exchanger designed to heat a liquid or gas using solar energy. The area of ​​application of flat solar collectors is heating systems for residential and industrial buildings, air conditioning systems, hot water supply systems, as well as power plants with a low-boiling working fluid, usually operating according to the Rankine cycle. Flat solar collectors (Figures 6 and 7) consist of a glass or plastic cover (single, double, triple), a heat-absorbing panel painted black on the sun-facing side, insulation on the back and a housing (metal, plastic, glass , wooden).

Any metal or plastic sheet with coolant channels can be used as a heat-absorbing panel. Heat-absorbing panels are made of aluminum or steel of two types: sheet-pipe and stamped panels (pipe in sheet). Plastic panels are not widely used due to their fragility and rapid aging under the influence of sunlight, as well as because of their low thermal conductivity. Under the influence of solar radiation, heat-sensing panels are heated to temperatures of 70–80 ◦ C, which exceeds the ambient temperature, which leads to an increase in the convective heat transfer of the panel to the environment and its own radiation to the sky. To achieve higher temperatures of the coolant, the surface of the plate is covered with spectrally selective layers that actively absorb short-wavelength radiation from the Sun and reduce its own thermal radiation in the long-wavelength part of the spectrum. Such designs based on "black nickel", "black chrome", copper oxide on aluminum, copper oxide on copper and others are expensive (their cost is often commensurate with the cost of the heat-absorbing panel itself). Another way to improve the performance of flat plate collectors is to create a vacuum between the heat absorbing panel and the transparent insulation to reduce heat loss (fourth generation solar collectors).

The principle of operation of the collector is based on the fact that it perceives solar radiation with a sufficiently high absorption coefficient of visible sunlight and has relatively low heat losses, including due to the low transmittance of a translucent glass coating for thermal radiation at operating temperature. It is clear that the temperature of the resulting coolant is determined by the heat balance of the collector. The incoming part of the balance represents the heat flux of solar radiation, taking into account the optical efficiency of the collector; the consumable part is determined by the recoverable useful heat, the total heat loss coefficient and the difference between the operating temperature and the environment. The perfection of a collector is determined by its optical and thermal efficiency.

The optical efficiency η o shows how much of the solar radiation that reaches the collector glazing surface is absorbed by the absorbing black surface, and takes into account the energy losses associated with absorption in the glass, reflection and the difference in the coefficient of thermal emissivity of the absorbing surface from unity.

The simplest solar collector with a single-glass translucent coating, polyurethane foam insulation of the remaining surfaces and an absorber covered with black paint has an optical efficiency of about 85%, and a heat loss factor of about 5-6 W / (m 2 · K) (Fig. 7). The set of a flat radiation-absorbing surface and pipes (channels) for the coolant forms a single structural element - an absorber. Such a collector in summer in mid-latitudes can heat water up to 55–60 ◦ C and has a daily capacity of 70–80 liters of water per square meter of heater surface.

To obtain higher temperatures, collectors made of evacuated pipes with a selective coating are used (Figure 8).

In a vacuum collector, the volume containing a black surface that absorbs solar radiation is separated from the environment by an evacuated space (each element of the absorber is placed in a separate glass tube, inside which a vacuum is created), which makes it possible to almost completely eliminate heat loss to the environment due to thermal conductivity and convection. Radiation losses are largely suppressed by the use of selective coating. In a vacuum manifold, the coolant can be heated to 120–150 ◦C. The efficiency of a vacuum collector is significantly higher than that of a flat collector, but it also costs much more.

The efficiency of solar energy installations largely depends on the optical properties of the surface that absorbs solar radiation. To minimize energy losses, it is necessary that in the visible and near infrared regions of the solar spectrum, the absorption coefficient of this surface should be as close to unity as possible, and in the wavelength region of the surface's own thermal radiation, the reflection coefficient should tend to unity. Thus, the surface must have selective properties - it is good to absorb short-wave radiation and reflect long-wave radiation well.

According to the type of mechanism responsible for the selectivity of optical properties, four groups of selective coatings are distinguished:

1. own;
2. two-layer, in which the upper layer has a high absorption coefficient in the visible region of the spectrum and a small one in the infrared region, and the lower layer has a high reflectivity in the infrared region;
3. with micro-relief, providing the required effect;
4. interference.

A small number of known materials have intrinsic selectivity of optical properties, for example, W, Cu 2 S, HfC.

The most widespread are two-layer selective coatings. A layer with a high reflectance in the long-wavelength region of the spectrum, for example copper, nickel, molybdenum, silver, aluminum, is applied to the surface, which must be given selective properties. On top of this layer, a layer is applied that is transparent in the long-wavelength region, but has a high absorption coefficient in the visible and near-infrared regions of the spectrum. Many oxides have these properties.

The selectivity of the surface can be provided due to purely geometric factors: the surface irregularities should be greater than the wavelength of light in the visible and near infrared regions of the spectrum and less than the wavelength corresponding to the intrinsic thermal radiation of the surface. Such a surface for the first of the indicated regions of the spectrum will be black, and for the second - specular.

Selective properties are exhibited by surfaces with a dendritic or porous structure with appropriate sizes of dendritic needles or pores.

Selective interference surfaces are formed by several alternating layers of metal and dielectric, in which short-wavelength radiation is extinguished due to interference, and long-wavelength radiation is freely reflected.

The scale of the use of solar heating systems

According to the IEA, by the end of 2001, the total area of ​​installed collectors in 26 countries, the most active in this regard, amounted to about 100 million m2, of which 27.7 million m2 falls on the share of non-glazed collectors, mainly used for heating water in swimming pools. The rest - flat glazed collectors and collectors with evacuated pipes - were used in hot water supply systems or for space heating. In terms of the area of ​​installed collectors per 1000 inhabitants, the leaders are Israel (608 m 2), Greece (298) and Austria (220). They are followed by Turkey, Japan, Australia, Denmark and Germany with a specific area of ​​installed collectors of 118–45 m 2/1000 inhabitants.

The total area of ​​solar collectors installed by the end of 2004 in the EU countries reached 13.96 million m2, and in the world it has already exceeded 150 million m2. The annual increase in the area of ​​solar collectors in Europe is on average 12%, and in some countries it is at the level of 28-30% or more. The world leader in the number of collectors per thousand inhabitants is Cyprus, where 90% of houses are equipped with solar installations (there are 615.7 m 2 solar collectors per thousand inhabitants), followed by Israel, Greece and Austria. The absolute leader in terms of the area of ​​installed collectors in Europe is Germany - 47%, followed by Greece - 14%, Austria - 12%, Spain - 6%, Italy - 4%, France - 3%. European countries are the undisputed leaders in the development of new technologies for solar heating systems, but they are far behind China in terms of commissioning new solar installations.

Of the total area of ​​solar collectors installed in the world in 2004, 78% were installed in China. The IED market in China has recently been growing at a rate of 28% per year.

In 2007, the total area of ​​solar collectors installed in the world was already 200 million m2, including more than 20 million m2 in Europe.

Today, on the world market, the cost of an IED (Figure 9), including a collector with an area of ​​5–6 m 2, a storage tank with a capacity of about 300 liters and the necessary fittings, is US $ 300–400 per 1 m 2 of a collector. Such systems are predominantly installed in single- and double-family houses and have a backup heater (electric or gas). When installing the storage tank above the collector, the system can operate on natural circulation (thermosyphon principle); when installing a storage tank in the basement - on a forced one.

In world practice, the most widespread are small solar heating systems. As a rule, such systems include solar collectors with a total area of ​​2–8 m 2, a storage tank, the capacity of which is determined by the area of ​​installed collectors, a circulation pump (depending on the type of heat circuit) and other auxiliary equipment.

Large active systems, in which the storage tank is located below the collectors and the circulation of the coolant is carried out using a pump, are used for the needs of hot water supply and heating. As a rule, in active systems participating in covering part of the heating load, a back-up heat source is provided, operating on electricity or gas.

A relatively new phenomenon in the practice of using solar heat supply is large systems capable of meeting the needs of hot water supply and heating of apartment buildings or entire residential areas. Such systems provide for either daily or seasonal heat storage. Daily accumulation assumes the possibility of operating the system with the consumption of heat accumulated over several days, seasonal - over several months. For seasonal heat accumulation, large underground reservoirs filled with water are used, into which all excess heat received from the collectors during the summer is discharged. Another option for seasonal accumulation is soil heating with the help of wells with pipes through which hot water circulates from the collectors.

Table 1 shows the main parameters of large solar systems with daily and seasonal heat storage in comparison with a small solar system for a single-family home.

Table 1. - Basic parameters of solar heat supply systems

Currently in Europe there are 10 solar heat supply systems with collector areas from 2400 to 8040 m2, 22 systems with collectors area from 1000 to 1250 m2 and 25 systems with collector areas from 500 to 1000 m2. Below are the specifications for some of the larger systems.

Hamburg (Germany). The area of ​​the heated premises is 14800 m 2. Solar collectors area - 3000 m 2. The volume of the water heat accumulator is 4500 m 3.

Fridrichshafen (Germany). The area of ​​the heated premises is 33000 m 2. The area of ​​solar collectors is 4050 m 2. The volume of the water heat accumulator is 12000 m 3.

Ulm-am-Neckar (Germany). The area of ​​the heated premises is 25000 m 2. Solar collectors area - 5300 m 2. The volume of the ground heat accumulator is 63400 m 3.

Rostock (Germany). The area of ​​the heated premises is 7000 m 2. Solar collectors area - 1000 m 2. The volume of the ground heat accumulator is 20,000 m 3.

Hemnitz (Germany). The area of ​​the heated premises is 4680 m 2. The area of ​​vacuum solar collectors is 540 m 2. The volume of the gravel-water heat accumulator is 8000 m 3.

Attenkirchen (Germany). The area of ​​the heated premises is 4500 m 2. The area of ​​vacuum solar collectors is 800 m 2. The volume of the ground heat accumulator is 9850 m 3.

Saro (Sweden). The system consists of 10 small houses with 48 apartments. Solar collectors area - 740 m 2. The volume of the water heat accumulator is 640 m 3. The solar system covers 35% of the total heat load of the heating system.

Currently, there are several companies in Russia that produce solar collectors suitable for reliable operation. The main ones are the Kovrov Mechanical Plant, NPO Mashinostroenie and ZAO ALTEN.

Collectors of the Kovrov Mechanical Plant (Figure 10), which do not have a selective coating, are cheap and simple in design, are mainly focused on the domestic market. More than 1,500 collectors of this type are currently installed in the Krasnodar Territory.

Collector NPO Mashinostroyenia is close to European standards in terms of characteristics. The absorber of the collector is made of an aluminum alloy with a selective coating and is designed mainly for operation in two-circuit heat supply circuits, since direct contact of water with aluminum alloys can lead to pitting corrosion of the channels through which the coolant passes.

Collector ALTEN-1 has a completely new design and meets European standards, it can be used both in single-circuit and double-circuit heat supply schemes. The collector is distinguished by high thermal performance, a wide range of possible applications, low weight and attractive design.

The experience of operating installations based on solar collectors has revealed a number of disadvantages similar systems... First of all, this is the high cost of collectors associated with selective coatings, increased transparency of glazing, evacuation, etc. A significant disadvantage is the need for frequent cleaning of glasses from dust, which practically excludes the use of the collector in industrial areas. During long-term operation of solar collectors, especially in winter conditions, there is a frequent failure of them due to the uneven expansion of the illuminated and darkened areas of the glass due to the violation of the integrity of the glazing. There is also a high percentage of collector failure during transportation and installation. A significant disadvantage of the systems with collectors is also the unevenness of the load during the year and day. The experience of operating collectors in the conditions of Europe and the European part of Russia with a high proportion of diffuse radiation (up to 50%) showed the impossibility of creating a year-round autonomous system hot water supply and heating. All solar systems with solar collectors in mid-latitudes require the installation of large storage tanks and inclusion in the system additional source energy, which reduces the economic effect of their use. In this regard, it is most advisable to use them in areas with a high intensity of solar radiation (not less than 300 W / m 2).

Efficient use of solar energy

In residential and office buildings, solar energy is mainly used in the form of heat to meet the needs for hot water supply, heating, cooling, ventilation, drying, etc.

From an economic point of view, the use of solar heat is most profitable when creating hot water supply systems and in installations for heating water close to them in technical implementation (in pools, industrial devices). Hot water supply is needed in every residential building, and since hot water needs change relatively little during the year, the efficiency of such installations is high and they quickly pay off.

As for solar heating systems, the period of their use during the year is short, during the heating season, the intensity of solar radiation is low and, accordingly, the area of ​​the collectors is much larger than in hot water supply systems, and the economic efficiency is lower. Usually, when designing, a solar heating and hot water supply system is combined.

In solar cooling systems, the operating period is even lower (three summer months), which leads to long equipment downtime and very low utilization rates. Considering the high cost of cooling equipment, the economic efficiency of the systems becomes minimal.

The annual utilization rate of equipment in combined heating and cooling systems (hot water supply, heating and cooling) is the highest, and at first glance, these systems are more profitable than combined heating and hot water supply systems. However, when the cost of the required solar collectors and cooling system mechanisms is taken into account, it turns out that such solar installations will be very expensive and hardly economically viable.

When creating solar heating systems, passive schemes should be used to increase the thermal insulation of the building and efficient use solar radiation coming through the window openings. The problem of thermal insulation must be solved on the basis of architectural and structural elements, using low-thermal-conductivity materials and structures. The missing heat is recommended to be replenished with the help of active solar systems.

Economic characteristics of solar collectors

The main problem of widespread use of solar installations is associated with their insufficient economic efficiency in comparison with traditional heat supply systems. The cost of heat energy in installations with solar collectors is higher than in installations with traditional fuels. The payback period of a solar thermal installation T approx can be determined by the formula:

The economic effect of installing solar collectors in the areas of centralized energy supply E can be defined as income from the sale of energy during the entire service life of the installation minus operating costs:

Table 2 shows the cost of solar heating systems (in 1995 prices). The data show that domestic developments are 2.5–3 times cheaper than foreign ones.

The low price of domestic systems is explained by the fact that they are made of cheap materials, simple in design, and focused on the domestic market.

Table 2. - Cost of solar heating systems

The specific economic effect (E / S) in the district heating zone, depending on the service life of the collectors, ranges from 200 to 800 rubles / m2.

Heat supply installations with solar collectors in regions remote from centralized power grids, which in Russia make up over 70% of its territory with a population of about 22 million people, have a much greater economic effect. These installations are designed to operate in an autonomous mode for individual consumers, where the demand for thermal energy is very significant. At the same time, the cost of traditional fuels is much higher than their cost in the areas of centralized heating due to transportation costs and fuel losses during transportation, i.e., the regional factor r r is included in the cost of fuel in the Central heating region:

where r p> 1 and for different regions can change its value. At the same time, the unit cost of the C plant remains almost unchanged in comparison with the C tr. Therefore, when replacing Ts t with Ts tr in the formulas

the calculated payback period of autonomous installations in areas remote from centralized networks decreases by r p times, and the economic effect increases in proportion to r p.

In today's Russia, when energy prices are constantly growing and are uneven across regions due to transportation conditions, the decision on the economic feasibility of using solar collectors is highly dependent on local socio-economic, geographic and climatic conditions.

Solar-geothermal heating system

From the point of view of uninterrupted supply of energy to the consumer, the most effective are combined technological systems that use two or more types of renewable energy sources.

Solar thermal energy can fully meet the needs for hot water in the house in the summer. In the autumn-spring period, up to 30% of the required energy for heating and up to 60% of the demand for hot water supply can be obtained from the Sun.

In recent years, geothermal heat supply systems based on heat pumps have been actively developing. In such systems, as noted above, low-potential (20–40 ◦ C) thermal water or petrothermal energy of the upper layers of the earth's crust is used as the primary heat source. When using the heat of the ground, ground heat exchangers are used, placed either in vertical wells with a depth of 100-300 m, or at a certain depth horizontally.

To efficiently provide heat and hot water to decentralized low-power consumers, a combined solar-geothermal system has been developed at the IPG DSC RAS ​​(Figure 11).

Such a system consists of a solar collector 1, a heat exchanger 2, a storage tank 3, a heat pump 7 and a well-heat exchanger 8. A coolant (antifreeze) circulates through the solar collector. The heat carrier is heated in the solar collector by the energy of the Sun and then gives off thermal energy to the water through the heat exchanger 2, mounted in the storage tank 3. Hot water is stored in the storage tank until it is used, so it must have good thermal insulation. In the first circuit, where the solar collector is located, natural or forced circulation of the coolant can be used. An electric heater 6 is also mounted in the storage tank. If the temperature in the storage tank drops below the set temperature (prolonged cloudy weather or few hours of sunshine in winter), the electric heater automatically turns on and warms up the water to the set temperature.

The solar collector unit is operated year-round and provides the consumer with hot water, while the low-temperature underfloor heating unit with a heat pump (HP) and a heat exchanger well 100-200 m deep is put into operation only during the heating season.

In the HP cycle, cold water with a temperature of 5 ◦ C descends in the annular space of the heat exchanger well and withdraws low-grade heat from the surrounding rock. Further, the water heated, depending on the depth of the well, to a temperature of 10–15 ◦ C, rises along the central column of pipes to the surface. To prevent heat backflow, the central column is thermally insulated from the outside. On the surface, water from the well enters the HP evaporator, where the low-boiling working agent is heated and evaporated. After the evaporator, the cooled water is again directed into the well. During the heating period, with constant circulation of water in the well, there is a gradual cooling of the rock around the well.

Calculated studies show that the radius of the cooling front during the heating period can reach 5–7 m. During the inter-heating period, when the heating system is turned off, a partial (up to 70%) recovery of the temperature field around the well occurs due to the influx of heat from rocks outside the cooling zone; it is not possible to achieve full recovery of the temperature field around the well during its downtime.

Solar collectors are installed based on the winter period of system operation, when the sunshine is minimal. In the summer, part of the hot water from the storage tank is directed into the well to fully restore the temperature in the rock around the well.

During the interheating period, valves 13 and 14 are closed, and when valves 15 and 16 are open, hot water from the accumulator tank is pumped into the annular space of the well by a circulation pump, where heat exchange with the rock surrounding the well occurs as it descends. Then the chilled water is directed back to the storage tank through the central heat-insulated column. In the heating season, on the contrary, valves 13 and 14 are open, and valves 15 and 16 are closed.

In the proposed technological system, the potential of solar energy is used to heat water in the hot water supply system and rocks around the well in the low-temperature heating system. Heat recovery in the rock makes it possible to operate the heat supply system in an economically optimal mode.

Solar thermal power plants

The sun is a significant source of energy on planet Earth. Solar energy is very often the subject of a wide variety of discussions. As soon as a project for a new solar power plant appears, questions arise about efficiency, capacity, investment volumes and payback periods.

There are scientists who see solar thermal power plants as a threat to the environment. Mirrors used in thermal solar power plants heat the air very strongly, which leads to climate change and the death of birds flying by. Despite this, in recent years, solar thermal power plants have become more widespread. In 1984, the first solar power plant went into operation near the Californian city of Cramer Junction in the Mohabe Desert (Figure 6.1). The station was named Solar Energy Generating System, or SEGS for short.

Rice. 6.1. Solar power plant in the Mohabe desert

This power plant uses solar radiation to generate steam, which turns a turbine and generates electricity. The production of solar thermal power on a large scale is quite competitive. Currently, solar thermal power plants with a total installed capacity of more than 400 MW have been built by US energy companies, which provide electricity to 350,000 people and replace 2.3 million barrels of oil per year. Nine power plants located in the Mohabe Desert have 354 MW of installed capacity. In other regions of the world, projects to use solar heat to generate electricity are also due to start soon. India, Egypt, Morocco and Mexico are developing related programs. Grants for their funding are provided by the Global Environment Program (GEF). In Greece, Spain and the United States, new projects are being developed by independent power producers.

According to the method of heat production, solar thermal power plants are divided into solar concentrators (mirrors) and solar ponds.

Solar concentrators

Thermal solar power plants concentrate solar energy using lenses and reflectors. Since this heat can be stored, such stations can generate electricity as needed, day and night, in any weather. Large mirrors - either point or line focus - concentrate the sun's rays to the point where the water turns into steam, while releasing enough energy to turn the turbine. These systems can convert solar energy into electricity with an efficiency of about 15%. All thermal power plants, except for solar ponds, use concentrators to achieve high temperatures, which reflect the sun's light from a larger surface onto a smaller receiver surface. Typically, such a system consists of a concentrator, receiver, heat carrier, storage system and power transmission system. Modern technologies include parabolic concentrators, solar parabolic mirrors and solar towers. They can be combined with fossil fuel plants and, in some cases, adapted for heat storage. The main advantage of such hybridization and heat storage is that such technology can provide dispatching of electricity production, that is, electricity generation can be produced during periods when there is a need for it. Hybridization and heat storage can increase the economic value of the electricity produced and lower its average cost.

Solar installations with a parabolic concentrator

Some thermal solar power plants use parabolic mirrors that concentrate sunlight on receiving tubes containing a heat transfer fluid. This liquid is heated to almost 400 ºC and is pumped through a series of heat exchangers; this generates superheated steam that drives a conventional turbine generator to generate electricity. To reduce heat loss, the receiving tube can be surrounded by a transparent glass tube placed along the focal line of the cylinder. Typically, such installations include uniaxial or biaxial solar tracking systems. In rare cases, they are stationary (Fig. 6.2).

Rice. 6.2. Solar plant with parabolic concentrator

Estimates of this technology show a higher cost of generated electricity than other solar thermal power plants. This is due to the low concentration of solar radiation, more low temperatures... However, subject to the accumulation of operating experience, improved technology and lower operating costs, parabolic concentrators may be the least expensive and most reliable technology in the near future.

Disc solar power plant

Plate-type solar installations are a battery of parabolic plate mirrors similar in shape to satellite dish that focus solar energy onto receivers located at the focal point of each dish (Figure 6.3). The liquid in the receiver is heated to 1000 ° C and is directly used to generate electricity in a small engine and generator connected to the receiver.

Rice. 6.3. Disc type solar plant

High optical efficiency and low initial cost make mirror / motor systems the most efficient solar technology of all. The Stirling engine and parabolic mirror system holds the world record for the efficiency of converting solar energy into electricity. In 1984, Rancho Mirage in California achieved a practical efficiency of 29%. Thanks to their modular design, such systems are the best option to meet the need for electricity both for autonomous consumers and for hybrid consumers operating on a common network.

Tower solar power plants

Tower-type solar power plants with a central receiver The tower-type solar power plants with a central receiver use a rotating field of heliostat reflectors. They focus sunlight onto a central receiver at the top of the tower, which absorbs thermal energy and drives a turbine generator (Figure 6.4, Figure 6.5).

Rice. 6.4. Solar power plant of a tower type with a central receiver

A computer-controlled biaxial tracking system sets the heliostats so that the reflected sunlight is stationary and always strikes the receiver. The liquid circulating in the receiver transfers heat to the heat accumulator in the form of vapor. The steam turns a turbine to generate electricity, or is directly used in industrial processes. Receiver temperatures range from 500 to 1500 ºC. Thanks to heat storage, the tower power plants have become a unique solar technology that allows them to generate electricity according to a predetermined schedule.

Rice. 6.5. Solar power plant "Solar Two" in California

Solar ponds

Neither focusing mirrors nor solar cells can generate energy at night. For this purpose, solar energy accumulated during the day must be stored in heat storage tanks. This process naturally occurs in the so-called solar ponds (Fig. 6.6).

Rice. 6.6. Diagram of the solar pond device
1. High concentration of salt. 2. Middle layer. 3. Low salt concentration. 4. Cold water "in" and hot water "from"

Solar ponds have a high salt concentration in the bottom water layers, a non-convective middle water layer in which the salt concentration increases with depth and a convection layer with a low salt concentration on the surface. Sunlight falls on the surface of the pond and heat is trapped in the lower layers of the water due to the high concentration of salt. High salinity water heated by solar energy absorbed by the pond bottom cannot rise due to its high density. It remains at the bottom of the pond, gradually warming up until it almost boils. The hot bottom "brine" is used day or night as a heat source, thanks to which a special turbine with an organic heat carrier can generate electricity. The middle layer of the sun pond acts as thermal insulation, preventing convection and heat loss from the bottom to the surface. The temperature difference between the bottom and the surface of the pond water is sufficient to power the generator. The coolant, passed through pipes through the lower layer of water, is fed further into a closed Rankine system, in which a turbine rotates to generate electricity.

Advantages and disadvantages of solar thermal power plants

Solar power plants of a tower type with a central receiver and solar power plants with parabolic concentrators work optimally as part of large, grid-connected power plants with a capacity of 30-200 MW, while disk-type solar power plants consist of modules and can be used both in stand-alone installations and in groups with a total capacity of several megawatts.

Table 6.1 Characteristics of solar thermal power plants

Solar parabolic concentrators are by far the most advanced solar energy technology and are likely to be used in the short term. Tower-type power plants with a central receiver, due to their effective heat storage capacity, can also become solar power plants in the near future. The modularity of the poppet type units allows them to be used in smaller units. Solar power plants of a tower type with a central receiver and installations of a disk type allow achieving higher values ​​of the efficiency of converting solar energy into electricity at a lower cost than power plants with solar parabolic concentrators. Table 6.1 shows the main characteristics of three options for solar thermal power generation.