The organizational structure of the CHP management and the main functions of the personnel. Brief description of the operation of TPP, TPP

Thermal power plants provide people with almost all the energy they need on the planet. People have learned to receive electricity in other ways, but still do not accept alternatives. It is not profitable for them to use fuel, they do not refuse it.

What is the secret of thermal power plants?

Thermal power plants it is no coincidence that they remain irreplaceable. Their turbine generates energy in the simplest way, using combustion. Due to this, it is possible to minimize construction costs, which are considered fully justified. There are such objects in all countries of the world, so one should not be surprised at their distribution.

The principle of operation of thermal power plants built on the combustion of huge amounts of fuel. As a result, electricity appears, which is first accumulated, and then distributed to certain regions. The schemes of thermal power plants remain almost constant.

What kind of fuel does the station use?

Each station uses a separate fuel. It is specially shipped to keep your workflow intact. This moment remains one of the problematic ones, as transport costs appear. What kinds of equipment does it use?

• Coal;
• Oil shale;
• Peat;
• Fuel oil;
• Natural gas.

Thermal circuits of thermal power plants are based on a certain type of fuel. Moreover, minor changes are made to them, ensuring the maximum efficiency. If they are not done, the main consumption will be excessive, therefore, the resulting electric current will not justify.

Types of thermal power plants

The types of thermal power plants are an important issue. The answer will tell you how the necessary energy appears. Today, serious changes are gradually being made, where the main source will be alternative types, but so far their use remains inappropriate.

1. Condensing (IES);
2. Combined Heat and Power (CHP);
3. State regional power plants (GRES).

The TPP power plant will require a detailed description. The views are different, so only consideration will explain why construction of this scale is being carried out.

Condensing (IES)

The types of thermal power plants start with condensing ones. Such CHP plants are used exclusively for generating electricity. Most often, it accumulates without immediately spreading. The condensation method provides maximum efficiency, so these principles are considered optimal. Today, in all countries, separate large-scale objects are distinguished, providing vast regions.

Nuclear installations are gradually emerging to replace traditional fuel. Only replacement remains an expensive and time-consuming process, since fossil fuel operation differs from other methods. Moreover, the shutdown of any station is impossible, because in such situations, entire regions are left without valuable electricity.

Combined Heat and Power Plant (CHP)

CHP plants are used for several purposes at once. They are primarily used to generate valuable electricity, but burning fuel also remains useful for generating heat. Due to this, cogeneration power plants continue to be applied in practice.

An important feature is that such types of thermal power plants are superior to others with a relatively small capacity. They provide separate areas so there is no need for bulk supplies. Practice shows how profitable such a solution is due to the laying of additional power lines. The principle of operation of a modern thermal power plant is unnecessary only because of the environment.

State District Power Plants

General information about modern thermal power plants do not mark the GRES. Gradually, they remain in the background, losing their relevance. Although the state-owned district power plants remain useful in terms of energy production.

Various types of thermal power plants provide support to vast regions, but their capacity is still insufficient. During the Soviet era, large-scale projects were carried out, which are now being closed. The reason was the inappropriate use of fuel. Although their replacement remains problematic, since the advantages and disadvantages of modern thermal power plants are primarily noted for large amounts of energy.

Which power plants are thermal? Their principle is based on fuel combustion. They remain indispensable, although they are actively calculating the equivalent replacement. Thermal power plants continue to prove their advantages and disadvantages in practice. Because of this, their work remains necessary.

Appointment of combined heat and power plants. Schematic diagram of CHP

CHP (combined heat and power plant) - designed for centralized supply of heat and electricity to consumers. Their difference from IES is that they use the heat of the steam spent in turbines for the needs of production, heating, ventilation and hot water supply. Due to this combination of electricity and heat generation, significant fuel savings are achieved in comparison with separate power supply (electricity generation at IES and heat energy at local boiler houses). Thanks to this method of combined production, CHPP achieves a sufficiently high efficiency, reaching 70%. Therefore, CHP plants are widespread in areas and cities with high heat consumption. The maximum capacity of the CHPP is less than the IES.

CHP plants are tied to consumers, because the radius of transfer of heat (steam, hot water) is approximately 15 km. Suburban CHP plants transfer hot water at a higher initial temperature over a distance of up to 30 km. Steam for industrial needs with a pressure of 0.8-1.6 MPa can be transmitted over a distance of no more than 2-3 km. With an average heat load density, the power of a CHPP usually does not exceed 300-500 MW. Only in large cities such as Moscow or St. Petersburg with a high heat load density does it make sense to build plants with a capacity of up to 1000-1500 MW.

The power of the CHP plant and the type of turbine generator are selected in accordance with the needs for heat and the parameters of steam used in production processes and for heating. The most widely used turbines are with one and two controlled steam extractions and condensers (see Fig.). Controlled extractions allow you to regulate the production of heat and electricity.

The CHPP regime - daily and seasonal - is mainly determined by heat consumption. The station works most economically if its electrical capacity corresponds to the heat output. At the same time, a minimum amount of steam enters the condensers. In winter, when the demand for heat is at its maximum, at the calculated air temperature during the operating hours of industrial enterprises, the load of the CHPP generators is close to the nominal one. During periods when heat consumption is low, for example, in summer, as well as in winter when the air temperature is higher than the calculated one and at night hours, the electric power of the CHP, corresponding to heat consumption, decreases. If the power system needs electrical power, the CHP plant must switch to a mixed mode, which increases the supply of steam to the low pressure part of the turbines and to the condensers. The efficiency of the power plant is thus reduced.

The maximum generation of electricity by cogeneration plants "on heat consumption" is possible only when working together with powerful IES and HPPs, which take on a significant part of the load during the hours when heat consumption is reduced.



CHP is a thermal power plant that not only produces electricity, but also provides heat to our homes in winter. Using the example of the Krasnoyarsk CHPP, let's see how almost any thermal power plant works.

There are 3 combined heat and power plants in Krasnoyarsk, the total electric power of which is only 1146 MW (for comparison, our Novosibirsk CHP 5 alone has a capacity of 1200 MW), but Krasnoyarsk CHP-3 was remarkable for me in that the station is new - not even a year has passed , as the first and so far the only power unit was certified by the System Operator and put into commercial operation. Therefore, I managed to photograph a beautiful station that was not yet dusty and learn a lot about the CHPP.

In this post, in addition to technical information about KrasHPP-3, I want to reveal the very principle of operation of almost any combined heat and power plant.

1. Three chimneys, the highest of them is 275 m high, the second highest - 180 m

The abbreviation CHP itself implies that the station generates not only electricity, but also heat (hot water, heating), moreover, heat generation is perhaps even more priority in our country known for harsh winters.

2. The installed electric capacity of Krasnoyarsk CHPP-3 is 208 MW, and the installed thermal capacity is 631.5 Gcal / h

Simplistically, the principle of operation of a CHPP can be described as follows:

It all starts with fuel. Coal, gas, peat, oil shale can act as fuel at different power plants. In our case, this is B2 grade brown coal from the Borodinsky open-pit mine located 162 km from the station. Coal is delivered by rail. Part of it is stored, the other part goes along conveyors to the power unit, where the coal itself is first crushed to dust and then fed into the combustion chamber - a steam boiler.

A steam boiler is a unit for generating steam with a pressure above atmospheric from the feed water continuously supplied to it. This is due to the heat released during the combustion of fuel. The boiler itself looks pretty impressive. At KrasTETs-3, the boiler height is 78 meters (26-storey building), and it weighs more than 7000 tons.

6. Steam boiler of EP-670 brand, manufactured in Taganrog. Boiler productivity 670 tons of steam per hour

I borrowed a simplified diagram of a steam boiler for a power plant from energoworld.ru so that you can understand its design

1 - combustion chamber (firebox); 2 - horizontal gas duct; 3 - convective shaft; 4 - furnace screens; 5 - ceiling screens; 6 - downpipes; 7 - drum; 8 - radiation-convective superheater; 9 - convective superheater; 10 - water economizer; 11 - air heater; 12 - blowing fan; 13 - bottom collectors of screens; 14 - slag chest of drawers; 15 - cold crown; 16 - burners. The diagram does not show an ash collector and a smoke exhauster.

7. View from above

10. The boiler drum is clearly visible. The drum is a cylindrical horizontal vessel with water and steam volumes, which are separated by a surface called the evaporation mirror.

Due to its high steam capacity, the boiler has developed heating surfaces, both evaporative and superheating. His firebox is prismatic, quadrangular with natural circulation.

A few words about the principle of boiler operation:

Feed water enters the drum, passing through the economizer, through the downpipes it descends into the lower collectors of the screens from the pipes, through these pipes the water rises and, accordingly, heats up, since a torch is burning inside the furnace. Water turns into a steam-water mixture, part of it falls into the external cyclones and the other part goes back to the drum. And there, and there is a separation of this mixture into water and steam. The steam goes to the superheaters, and the water repeats its path.

11. The cooled flue gases (about 130 degrees) leave the furnace into the electrostatic precipitators. In electrostatic precipitators, gases are cleaned from ash, the ash is removed to the ash disposal area, and the cleaned flue gases go into the atmosphere. The effective degree of flue gas cleaning is 99.7%.
The photo shows the same electrostatic precipitators.

Passing through the superheaters, the steam is heated to a temperature of 545 degrees and enters the turbine, where under its pressure the rotor of the turbine generator rotates and, accordingly, electricity is generated. It should be noted that in condensing power plants (GRES) the water circulation system is completely closed. All steam passing through the turbine is cooled and condensed. Once again turned into a liquid state, water is reused. And in CHP turbines, not all steam enters the condenser. Steam extraction is carried out - production (the use of hot steam in any industries) and heating (hot water supply network). This makes the CHP plant economically more profitable, but it has its drawbacks. The disadvantage of combined heat and power plants is that they must be built close to the final consumer. Heating mains costs a lot of money.

12. At Krasnoyarsk CHPP-3, a direct-flow system of technical water supply is used, which makes it possible to refuse the use of cooling towers. That is, water for cooling the condenser and use in the boiler is taken directly from the Yenisei, but before that it undergoes purification and desalination. After use, the water returns through the canal back to the Yenisei, passing through a diffuse discharge system (mixing heated water with cold water in order to reduce thermal pollution of the river)

14. Turbogenerator

I hope I managed to clearly describe the principle of operation of the CHP. Now a little about the KrasHPP-3 itself.

The construction of the station began back in 1981, but, as it happens in Russia, due to the collapse of the USSR and the crises, it was not possible to build the CHP on time. From 1992 to 2012, the station worked as a boiler house - it heated water, but it only learned how to generate electricity on March 1 of last year.

Krasnoyarsk CHP-3 belongs to Yenisei TGC-13. The CHPP employs about 560 people. At present, Krasnoyarsk CHPP-3 provides heat supply to industrial enterprises and the housing and communal sector of the Soviet district of Krasnoyarsk - in particular, the Severny, Vzletka, Pokrovsky and Innokentievsky microdistricts.

17.

19. CPU

20. There are also 4 hot water boilers operating at KrasTETS-3

21. Peephole in the firebox

23. And this photo was taken from the roof of the power unit. The large pipe has a height of 180m, the smaller one is the pipe of the starting boiler room.

24. Transformers

25. As a switchgear at KrasTETs-3, a 220 kV gas-insulated closed switchgear (ZRUE) is used.

26. Inside the building

28. General view of the switchgear

29. That's all. Thank you for attention

The supply of heat and electricity to the population is one of the main tasks of the state. In addition, it is impossible to imagine a developed manufacturing and processing industry without electricity generation, without which the country's economy cannot exist in principle.

One of the ways to solve the problem of energy shortages is to build a CHP. The decoding of this term is quite simple: it is the so-called combined heat and power plant, which is one of the most common types of thermal power plants. In our country, they are very common, since they work on organic fossil fuels (coal), the characteristics of which are very modest.

Features:

That's what a CHP is. The decoding of the concept is already familiar to you. But what are the features of this type of power plant? It's no coincidence that they are singled out in a separate category !?

The fact is that they generate not only electricity, but also heat, which is supplied to consumers in the form of hot water and steam. It should be noted that electricity is a by-product, as the steam supplied to the heating systems first turns the turbines of the generators. The good thing about combining two plants (a boiler house and a power plant) is that it can significantly reduce fuel consumption.

However, this also leads to a rather insignificant "area of \u200b\u200bdistribution" of CHP. The decoding is simple: since not only electricity is supplied from the station, which can be transported thousands of kilometers with minimal losses, but also a heated coolant, they cannot be located at a considerable distance from the settlement. It is not surprising that almost all CHPs are built in the immediate vicinity of the cities, whose residents they heat and light.

Environmental significance

Due to the fact that during the construction of such a power plant it is possible to get rid of many old city boiler houses, which play an extremely negative role in the ecological state of the district (a huge amount of soot), the air purity in the city can sometimes be improved by an order of magnitude. In addition, the new CHPPs make it possible to eliminate garbage heaps at city dumps.

The latest purification equipment allows you to effectively clean up the waste, and the energy efficiency of such a solution turns out to be extremely high. So, the release of energy from burning a ton of oil is identical to the volume that is released when disposing of two tons of plastic. And this "good" will be enough for decades to come!

Most often, the construction of a CHP plant involves the use of fossil fuels, as we have already discussed above. However, in recent years, it is planned to create which will be mounted in the remote regions of the Far North. Since the supply of fuel there is extremely difficult, nuclear power is the only reliable and constant source of energy.

What are they like?

There are thermal power plants (photos of which are in the article), industrial and "household", heating. As you might guess from the name, industrial power plants provide electricity and heat to large industrial enterprises.

Often they are built at the stage of plant construction, making up a single infrastructure with it. Accordingly, “household” varieties are being built not far from the residential neighborhoods of the city. In industrial applications, it is transmitted in the form of hot steam (no more than 4-5 km), in the case of heating ones - using hot water (20-30 km).

Station equipment information

The main equipment of these enterprises are turbine units, which convert mechanical energy into electricity, and boilers, which are responsible for generating steam, which rotates the flywheels of generators. The turbine unit includes both the turbine itself and the synchronous generator. Pipes with a backpressure of 0.7-1.5 MN / m2 are installed at those CHPPs that supply heat and energy to industrial facilities. Models with a pressure of 0.05-0.25 MN / m2 are used to provide household consumers.

Efficiency issues

In principle, all the generated heat can be fully utilized. Here are just the amount of electricity that is generated at the CHPP (you already know the decoding of this term), directly depends on the heat load. Simply put, in the spring-summer period, its production drops to almost zero. Thus, backpressure installations are used only to supply industrial capacities, for which the consumption is more or less uniform throughout the entire period.

Condensing units

In this case, only the so-called “extraction steam” is used to supply consumers with heat, and all the rest of the heat is often simply lost, dissipating in the environment. To reduce energy losses, such CHP plants must operate with minimal heat output to the condensing unit.

However, since the times of the USSR, such stations have been built in which a hybrid mode is structurally provided: they can operate as conventional condensing CHP plants, but their turbine generator is quite capable of operating in a back pressure mode.

Universal varieties

It is not surprising that steam condensing installations have become the most widespread due to their versatility. So, only they make it possible to practically independently regulate the electrical and thermal load. Even if the heat load is not foreseen at all (in the event of a particularly hot summer), the population will be supplied with electricity according to the previous schedule (Zapadnaya CHPP in St. Petersburg).

"Thermal" types of CHP

As you can already understand, the heat production at this type of power plant is extremely uneven throughout the year. Ideally, about 50% of hot water or steam is used to heat consumers, and the rest of the heat carrier is used to generate electricity. This is how the Yugo-Zapadnaya CHPP works in the Northern capital.

Heat release in most cases is carried out in two ways. If an open version is used, then hot steam from the turbines goes directly to consumers. If a closed operation was chosen, the coolant is supplied after passing through the heat exchangers. The choice of the scheme is determined based on many factors. First of all, the distance from the object provided with heat and electricity, the number of population and the season are taken into account. Thus, the Yugo-Zapadnaya CHPP in St. Petersburg operates under a closed scheme, since it provides greater efficiency.

Fuel characteristics

Solid, liquid can be used. Since CHP plants are often built in close proximity to large settlements and cities, it is often necessary to use quite valuable types of it, gas and fuel oil. The use of coal and garbage as such in our country is rather limited, since not all stations have modern efficient air cleaning equipment installed.

To clean the exhaust from the installations, special particulate traps are used. To disperse solid particles in sufficiently high layers of the atmosphere, pipes 200-250 meters high are built. As a rule, all combined heat and power plants (CHP) are located at a sufficiently large distance from water supply sources (rivers and reservoirs). That is why artificial systems are used, which include cooling towers. Direct-flow water supply is extremely rare, in very specific conditions.

Features of gas stations

Gas CHPPs stand apart. Heat supply to consumers is carried out not only at the expense of energy, which is generated during combustion, but also during the utilization of heat from gases that are formed in this case. The efficiency of such installations is extremely high. In some cases, nuclear power plants can also be used as CHP. This is especially common in some Arab countries.

There, these stations play two roles at once: they provide the population with electricity and technical water, since they simultaneously perform functions. Now we will consider the main CHPPs in our country and neighboring countries.

Yugo-Zapadnaya, Saint Petersburg

In our country, Zapadnaya CHPP, which is located in St. Petersburg, is famous. Registered as OJSC Yugo-Zapadnaya CHPP. The construction of this modern facility pursued several functions at once:

• Compensation for the severe shortage of thermal energy that hindered the intensification of the housing program.
• Improving the reliability and energy efficiency of the city system as a whole, since it was with this aspect that St. Petersburg had problems. The CHPP has partially solved this problem.

But this station is also known for being one of the first in Russia to meet the strictest environmental requirements. The city government has allocated more than 20 hectares for the new enterprise. The fact is that a reserve area left over from the Kirovsky district was set aside for construction. In those parts there was an old ash collection from CHPP-14, and therefore the area was not suitable for housing, but it is extremely well located.

The launch took place at the end of 2010, and the ceremony was attended by almost all city leaders. Two state-of-the-art automatic boiler plants were commissioned.

Murmansk

Murmansk is known as the base of our fleet on the Baltic Sea. But it is also characterized by the extreme severity of climatic conditions, which imposes certain requirements on its energy system. It is not surprising that the Murmansk CHPP is in many ways a completely unique technical facility, even on a national scale.

It was commissioned back in 1934, and since then it has continued to regularly supply the residents of the city with heat and electricity. However, in the first five years, the Murmansk CHPP was an ordinary power plant. The first 1,150 meters of the heating main were laid only in 1939. The point is the neglected Nizhne-Tulomskaya hydroelectric power station, which almost completely covered the city's electricity needs, and therefore it became possible to free up part of the heat generation for heating city houses.

The plant is characterized by the fact that it operates in a balanced mode all year round, since its thermal and “power” output are approximately equal. However, in the conditions of the polar night, the CHPP at some peak moments begins to use most of the fuel specifically for generating electricity.

Novopolotsk station, Belarus

Design and construction of this facility began in August 1957. The new Novopolotsk CHPP was supposed to solve the problem of not only heating the city, but also providing electricity to an oil refinery under construction in the same area. In March 1958, the project was finally signed, approved and approved.

The first stage was commissioned in 1966. The second was launched in 1977. At the same time, the Novopolotsk CHPP was modernized for the first time, its peak capacity was increased to 505 MW, and a little later the third stage of construction was laid, completed in 1982. In 1994 the station was converted to liquefied natural gas.

To date, about 50 million US dollars have already been invested in the modernization of the enterprise. Thanks to such an impressive cash infusion, the enterprise was not only completely switched to gas, but also received a huge amount of completely new equipment, which will allow the station to serve for tens of years.

conclusions

Oddly enough, but today it is the outdated CHP plants that are truly versatile and promising stations. Using modern neutralizers and filters, water can be heated by burning almost all the garbage that a settlement produces. This achieves a triple benefit:

• Landfills are unloaded and cleared.
• The city receives cheap electricity.
• The problem with heating is being solved.

In addition, in the coastal areas, it is quite possible to build thermal power plants, which at the same time will act as desalination plants for sea water. Such a liquid is quite suitable for irrigation, for livestock complexes and industrial enterprises. In a word, the real technology of the future!

How is the CHP plant arranged? CHP units. CHP equipment. The principles of the CHPP operation. CCGT-450.

Hello dear ladies and gentlemen!

When I was studying at the Moscow Power Engineering Institute, I lacked practice. At the institute, you deal mainly with "pieces of paper", but I already wanted to see "pieces of iron". It was often difficult to understand how this or that unit works, having never seen it before. The sketches offered to students do not always allow them to understand the full picture, and few could imagine the true design, for example, of a steam turbine, considering only the pictures in the book.

This page is intended to fill the existing gap and provide all those interested, albeit not too detailed, but visual information about how the equipment of Teplo-Electro Central (CHP) is arranged "from the inside". The article discusses a type of CCGT-450 power unit that is quite new for Russia, which uses a combined cycle - steam-gas in its operation (most CHP plants use only the steam cycle so far).

The advantage of this page is that the photographs presented on it were taken at the time of the construction of the power unit, which made it possible to photograph the device of some technological equipment in disassembled form. In my opinion, this page will be most useful for students of energy specialties - to understand the essence of the issues studied, as well as for teachers - to use individual photographs as methodological material.

The energy source for the operation of this power unit is natural gas. When gas is burned, thermal energy is released, which is then used to operate all equipment of the power unit.

In total, three power machines operate in the power unit scheme: two gas turbines and one steam turbine. Each of the three machines is designed for a nominal electrical power output of 150MW.

Gas turbines are similar in principle to jet engines.

Gas turbines require two components to operate: gas and air. Air from the street enters through the air intakes. The air intakes are covered with grates to protect the gas turbine from birds and all kinds of debris. They also have an anti-icing system that prevents ice from freezing in winter.

Air enters the inlet of the gas turbine compressor (axial type). After that, in compressed form, it enters the combustion chambers, where, in addition to air, natural gas is supplied. In total, two combustion chambers are installed on each gas turbine unit. They are located on the sides. In the first photo below, the air duct has not yet been assembled, and the left combustion chamber is covered with a cellophane film, in the second, a platform has already been mounted around the combustion chambers, an electric generator is installed:

Each combustion chamber has 8 gas burners:

In the combustion chambers, the combustion process of the gas-air mixture and the release of thermal energy take place. This is what combustion chambers look like "from the inside" - exactly where the flame burns continuously. The walls of the chambers are lined with refractory lining:

In the lower part of the combustion chamber there is a small viewing window that allows observing the processes taking place in the combustion chamber. The video below demonstrates the combustion process of the gas-air mixture in the combustion chamber of a gas turbine unit at the time of its start-up and when operating at 30% of the rated power:

The air compressor and the gas turbine are on the same shaft, and some of the turbine torque is used to drive the compressor.

The turbine does more work than is required to drive the compressor, and the excess of this work is used to drive the "payload". An electric generator with an electric power of 150 MW is used as such a load - it is in it that electricity is generated. In the photo below, the "gray barn" is just an electric generator. The generator is also on the same shaft as the compressor and turbine. Everything together rotates at 3000 rpm.

When passing through a gas turbine, the combustion products give it part of their thermal energy, but not all of the energy of the combustion products is used to rotate the gas turbine. A significant part of this energy cannot be used by the gas turbine, therefore, the combustion products at the outlet of the gas turbine (exhaust gases) still carry with them a lot of heat (the temperature of the gases at the outlet of the gas turbine is about 500° FROM). In aircraft engines, this heat is wastefully released into the environment, but in the considered power unit it is used further - in the steam-power cycle. For this, the exhaust gases from the outlet of the gas turbine are "blown in" from below into the so-called. "waste heat boilers" - one for each gas turbine. Two gas turbines - two waste heat boilers.

Each such boiler is a structure several stories high.

These boilers use the thermal energy from the gas turbine exhaust to heat water and convert it to steam. Subsequently, this steam is used when working in a steam turbine, but more on that later.

For heating and evaporation, water flows inside tubes with a diameter of approximately 30 mm, arranged horizontally, and the exhaust gases from the gas turbine "wash" these tubes from the outside. This is how heat is transferred from gases to water (steam):

Having given up most of the thermal energy to steam and water, the exhaust gases end up at the top of the waste heat boiler and are discharged through a chimney through the roof of the workshop:

On the outside of the building, chimneys from two waste heat boilers converge into one vertical chimney:

The following photos allow you to estimate the dimensions of the chimneys. The first photo shows one of the "corners" with which the chimneys of waste heat boilers are connected to the vertical shaft of the chimney; the rest of the photos show the process of installing the chimney.

But let's return to the design of waste heat boilers. The pipes through which the water passes inside the boilers are divided into many sections - tube bundles, which form several sections:

1. Economizer section (which at this power unit has a special name - Gas Condensate Heater - HPC);

2. Evaporation section;

3. Superheating section.

The economizer section is used to heat water from a temperature of the order of 40 ° Cto a temperature close to the boiling point. After that, the water enters the deaerator - a steel container, where the parameters of the water are maintained such that gases dissolved in it begin to intensively release from it. The gases collect at the top of the vessel and are vented to the atmosphere. Removing gases, especially oxygen, is necessary to prevent rapid corrosion of the process equipment with which our water comes in contact.

Having passed the deaerator, the water acquires the name "feed water" and enters the input of the feed pumps. This is what the feed pumps looked like when they were just brought to the station (there are 3 of them in total):

The feed pumps are electrically driven (asynchronous motors are powered from 6 kV voltage and have a power of 1.3 MW). Between the pump itself and the electric motor there is a hydraulic coupling - the unit, allowing you to smoothly change the pump shaft speed over a wide range.

The principle of operation of a fluid coupling is similar to the principle of operation of a fluid coupling in automatic transmissions of cars.

Inside there are two wheels with blades, one "sits" on the shaft of the electric motor, the other on the shaft of the pump. The space between the wheels can be filled with oil to different levels. The first wheel, rotated by the engine, creates a flow of oil, "hitting" the blades of the second wheel, and causing it to rotate. The more oil is poured between the wheels, the better "adhesion" the shafts will have with each other, and the more mechanical power will be transmitted through the fluid coupling to the feed pump.

The oil level between the wheels is changed using the so-called. "scoop pipe" that pumps oil from the space between the wheels. The position of the scoop tube is regulated by a special actuator.

The feed pump itself is centrifugal, multistage. Note that this pump develops the total steam pressure of the steam turbine and even exceeds it (by the value of the hydraulic resistance of the remaining part of the waste heat boiler, hydraulic resistance of pipelines and fittings).

It was not possible to see the design of the impellers of the new feed pump (since it was already assembled), but parts of the old feed pump of a similar design were found on the territory of the station. The pump consists of alternating rotating centrifugal wheels and stationary guide discs.

Fixed guide disc:

Impellers:

From the outlet of the feed pumps, feed water is supplied to the so-called. "separator drums" - horizontal steel tanks intended for separating water and steam:

Each waste heat boiler has two separator drums (4 in total at the power unit). Together with the tubes of the evaporating sections inside the waste heat boilers, they form the circulation loops of the steam-water mixture. It works as follows.

Water with a temperature close to the boiling point enters the tubes of the evaporating sections, flowing through which it heats up to the boiling point and then partially turns into steam. At the outlet of the evaporation section, we have a steam-water mixture that enters the drum-separators. Special devices are mounted inside the separator drums

Which help to separate steam from water. The steam is then fed to the superheating section, where its temperature is further increased, and the water separated in the separator drum (separated) is mixed with the feed water and again enters the evaporation section of the waste heat boiler.

After the superheating section, steam from one waste heat boiler is mixed with the same steam from the second waste heat boiler and enters the turbine. Its temperature is so high that the pipelines through which it passes, if you remove the thermal insulation from them, glow in the dark with a dark red glow. And now this steam is fed to the steam turbine in order to give off part of its thermal energy in it and to do useful work.

The steam turbine has 2 cylinders - a high pressure cylinder and a low pressure cylinder. The low pressure cylinder is double-flow. It splits the steam into 2 streams working in parallel. The cylinders contain the turbine rotors. Each rotor, in turn, consists of stages - discs with blades. The steam "strikes" the blades and causes the rotors to rotate. The photo below reflects the general design of a steam turbine: closer to us - a high-pressure rotor, further from us - a double-flow low-pressure rotor

This is what the low pressure rotor looked like when it was just unpacked from its original packaging. Note that it only has 4 steps (not 8):

And here is the high-pressure rotor on closer inspection. It has 20 steps. Pay attention also to the massive steel turbine casing, which consists of two halves - the lower and the upper (only the lower one in the photo), and the studs with which these halves are connected to each other. To make the housing faster when starting up, but at the same time, it warms up more evenly, a "flange and stud" steam heating system is used - see a special channel around the studs? It is through it that a special steam flow passes to warm up the turbine housing during its start-up.

In order for the steam to "hit" the rotor blades and make them rotate, this steam must first be directed and accelerated in the desired direction. For this, the so-called. nozzle grids - fixed sections with fixed blades located between the rotating discs of the rotors. The nozzle grids DO NOT rotate - they are NOT movable and only serve to direct and accelerate steam in the desired direction. In the photo below, steam passes "from behind these blades towards us" and "spins" around the turbine axis counterclockwise. Further, "hitting" the rotating blades of the rotor discs, which are located immediately behind the nozzle grid, the steam transfers its "rotation" to the turbine rotor.

The photo below shows the parts of the nozzle grids prepared for installation.

And in these photographs - the lower part of the turbine housing with the halves of the nozzle grids already installed in it:

After that, the rotor is "inserted" into the body, the upper halves of the nozzle grids are mounted, then the upper part of the body, then various pipelines, thermal insulation and a casing:

After passing through the turbine, the steam enters the condensers. This turbine has two condensers according to the number of flows in the low-pressure cylinder. Take a look at the photo below. It clearly shows the lower part of the steam turbine housing. Pay attention to the rectangular parts of the low pressure cylinder body, closed at the top with wooden shields. These are the steam turbine exhaust and condenser inlets.

When the casing of the steam turbine is completely assembled, a space is formed at the outlets of the low-pressure cylinder, the pressure in which during the operation of the steam turbine is approximately 20 times lower than the atmospheric pressure, therefore, the casing of the low-pressure cylinder is designed not to resist pressure from the inside, but to resist pressure from outside - i.e. e. atmospheric air pressure. The condensers themselves are located under the low pressure cylinder. In the photo below, these are rectangular containers with two hatches each.

The design of the condenser is similar to that of a waste heat boiler. Inside it are many tubes with a diameter of approximately 30mm. If we open one of the two hatches of each condenser and look inside, we see "tube sheets":

Cooling water, called process water, flows through these pipes. Steam from the steam turbine exhaust ends up in the space between the tubes outside of them (behind the tube plate in the photo above), and, giving off residual heat to industrial water through the walls of the tubes, condenses on their surface. The steam condensate flows down, accumulates in the condensate traps (in the lower part of the condensers), and then enters the inlet of the condensate pumps. Each condensate pump (there are 5 of them in total) is driven by a three-phase asynchronous electric motor designed for a voltage of 6 kV.

From the outlet of the condensate pumps, water (condensate) is again fed to the inlet of the economizer sections of the waste heat boilers and, thus, the steam power cycle is closed. The entire system is almost hermetically sealed and water, which is a working fluid, is repeatedly converted into steam in waste heat boilers, in the form of steam it does work in a turbine to again turn into water in turbine condensers, etc.

This water (in the form of water or steam) is constantly in contact with the internal parts of the technological equipment, and in order not to cause their rapid corrosion and wear, it is chemically prepared in a special way.

But back to the steam turbine condensers.

The process water heated in the tubes of the steam turbine condensers is discharged from the workshop through the underground pipelines of the technical water supply and supplied to the cooling towers in order to give them the heat taken from the steam from the turbine to the surrounding atmosphere. The photos below show the construction of the cooling tower erected for our power unit. The principle of its operation is based on spraying warm industrial water inside the cooling tower with the help of shower devices (from the word "shower"). Water droplets fall down and give their heat to the air inside the cooling tower. The heated air rises up, and cold air from the street comes in its place from the bottom of the cooling tower.

This is what a cooling tower looks like at its base. It is through the "slot" at the bottom of the cooling tower that cold air comes in to cool the process water

At the bottom of the cooling tower there is a drainage basin, where drops of industrial water fall and collect, released from the sprinklers and given their heat to the air. Above the pool there is a system of distributing pipes, through which warm industrial water is supplied to the shower devices

The space above and below the sprinkler devices is filled with a special padding of plastic blinds. The lower louvers are designed to distribute the "rain" more evenly over the area of \u200b\u200bthe cooling tower, and the upper louvers are designed to trap small water droplets and prevent unnecessary entrainment of process water with air through the top of the cooling tower. However, at the time of taking the submitted photos, the plastic blinds had not yet been installed.

Bo " the largest part of the cooling tower in terms of height is not filled with anything and is intended only for creating thrust (heated air rises up). If we stand above the distribution pipelines, we see that there is nothing above and the rest of the cooling tower is empty.

The following video captures the experience of being inside a cooling tower.

At the time when the photographs of this page were taken, the cooling tower built for the new power unit was not yet operational. However, there were other cooling towers on the territory of this TPP that were in operation, which made it possible to capture a similar cooling tower in operation. Steel louvers at the bottom of the cooling tower are designed to regulate the flow of cold air and prevent overcooling of service water in winter

The process water cooled and collected in the cooling tower pool is again fed to the inlet of the steam turbine condenser tubes to remove a new portion of heat from the steam, etc. In addition, the process water is used to cool other process equipment, such as power generators.

The following video shows how process water is cooled in a cooling tower.

Since the process water is in direct contact with the surrounding air, dust, sand, grass and other dirt gets into it. Therefore, a self-cleaning filter is installed at the inlet of this water to the workshop, on the inlet pipeline of service water. This filter consists of several sections mounted on a rotating wheel. Through one of the sections, from time to time, a backflow of water is organized to flush it. Then the wheel with sections turns, and the flushing of the next section begins, etc.

This is what this self-cleaning filter looks like from the inside of the service water pipeline:

And so outside (the drive electric motor has not yet been mounted):

Here it is necessary to digress and say that the installation of all technological equipment in the turbine shop is carried out using two bridge cranes. Each crane has three separate winches to handle loads of different weights.

Now I would like to tell you a little about the electrical part of this power unit.

Electricity is generated by three power generators driven by two gas turbines and one steam turbine. Part of the equipment for the installation of the power unit was brought by road, and part by rail. A railway was laid directly to the turbine shop, along which large-sized equipment was transported during the construction of the power unit.

The photo below shows the process of delivering the stator of one of the generators. Let me remind you that each generator has a rated electrical power of 150 MW. Note that the railway platform on which the generator stator was delivered has 16 axles (32 wheels).

The railway has a slight rounding at the entrance to the workshop, and given that the wheels of each wheelset are rigidly fixed on their axles, when driving on a rounded section of the railway, one of the wheels of each wheelset is forced to slip (since the rails have different length). The video below shows how this happened when the platform with the stator of the generator was moving. Pay attention to how the sand bounces on the sleepers when the wheels slip on the rails.

Due to the large mass, the installation of the stators of the electric generators was carried out using both overhead cranes:

The photo below shows an internal view of the stator of one of the electric generators:

And this is how the installation of rotors of electric generators was carried out:

The output voltage of the generators is about 20kV. The output current is thousands of amperes. This electricity is removed from the turbine shop and fed to step-up transformers outside the building. To transfer electricity from power generators to step-up transformers, the following electric wires are used (current flows through the central aluminum pipe):

To measure the current in these "wires", the following current transformers are used (in the third photo above, the same current transformer is standing vertically):

The photo below shows one of the step-up transformers. Output voltage - 220kV. From their outputs, electricity is supplied to the power grid.

In addition to electricity, the CHPP also generates heat energy used for heating and hot water supply to nearby areas. For this purpose, steam is extracted in the steam turbine, that is, part of the steam is removed from the turbine before reaching the condenser. This steam, which is still hot enough, enters the network heaters. The mains heater is a heat exchanger. It is very similar in design to a steam turbine condenser. The difference lies in the fact that the pipes do not flow process water, but network water. There are two mains heaters at the power unit. Let's take another look at the photo with the condensers of the wind turbine. Rectangular tanks are condensers, and "round" ones are just the mains heaters. Let me remind you that all of this is located under the steam turbine.

The network water heated in the pipes of the network heaters is supplied through the underground pipelines of the network water to the heating network. Heating the building of the districts located around the CHPP, and giving them its heat, the network water returns to the station again to be reheated in the network heaters, etc.

The operation of the entire power unit is controlled by the Ovation automated process control system of the American corporation Emerson

And here is what the cable half-floor looks like, located under the premises of the APCS. Through these cables, signals from a variety of sensors are sent to the APCS, and signals are also sent to the actuators.

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