A good do-it-yourself styling model. Which Stirling Engine Has the Best Design with Maximum Efficiency

Explanation of the operation of the Stirling engine.

We start by marking the flywheel.

Six holes failed. It turns out not beautiful. The holes are small and the body between them is thin.

For one, we sharpen the counterweights for the crankshaft. The bearings are pressed in. Subsequently, the bearings are pressed out and a thread on M3 is cut in their place.

I milled, but you can also use a file.

This is part of the connecting rod. The rest is soldered with PSR.

Working with a sweep over the sealing washer.

Stirling bed drilling. The hole that connects the displacer to the slave cylinder. Drill for 4.8 thread for M6. Then it must be muffled.

Drilling of the working cylinder liner, for reaming.

Drilling for thread on M4.

How it was done.

The dimensions are given taking into account the converted. Two pairs of cylinder-piston were made, at 10mm. and 15mm. Both have been tested if the cylinder is set to 15mm. then the piston stroke will be 11-12mm. and does not work. But 10mm. with a stroke of 24mm. just right.

The dimensions of the connecting rods. Brass wire Ф3mm is soldered to them.

Connecting rod mount - Bearing option failed. When the connecting rod is tightened, the bearing deforms and creates additional friction. Instead of a bearing, I made Al. bushing with bolt.

Sizes of some parts.

Some dimensions are on the flywheel.

Some sizes are both attached to the shaft and articulation.

Place an asbestos gasket 2-3mm between the cooler and the fire chamber. It is advisable to put paronite gaskets or something that conducts less heat under the bolts that tighten both parts.

Displacing the heart of styrling, it should be light and have little heat conduction. The stock is taken from the same old hard drive. This is one of the guide rails of a linear motor, very suitable, hardened, chrome plated. In order to cut the thread, wrapped the middle with a soaked rag, and heated the ends to red.

Connecting rod with slave cylinder. Overall length 108mm. Of these, 32mm is a piston with a diameter of 10mm. The piston should go into the cylinder easily, without noticeable scoring. To check, close it tightly with a finger from below, and insert the piston from above, it should be released very slowly downward.

I planned to do this, but made changes in the process. In order to find out the stroke of the working cylinder, we move the displacer into the refrigerator, and the working cylinder is pulled by 25mm. We heat the fire chamber. Carefully put a ruler under the working connecting rod, and remember the data. We sharply push the displacer, and how much the slave cylinder will move is its stroke. This size plays a very important role.

View of the working cylinder. Crank length 83mm. Stroke 24mm. The handwheel is attached to the shaft with an M4 screw. The photo shows his head. And in this way the displacer connecting rod counterweight is also attached.

View of the displacer connecting rod. Total length with displacer 214mm. Crank length 75mm. Stroke 24mm. Pay attention to the U-shaped groove on the flywheel. It was made for power take-off. The injector was either a generator or through a bag to the cooler fan. The flywheel pylon has dimensions of 68x25x15. The upper part is milled on one side to a depth of 7mm and a length of 32mm. The center of the bearing at the bottom is 55mm. It is fastened from below with two bolts on M4. The distance between the centers of the pylons is 126mm.

View of the combustion chamber and cooler. The engine casing is pressed into the pylon. The dimensions of the pylon are 47x25x15, with a recess for 12mm landing. It is attached to the bottom of the board with two bolts on M4.

Lamp 40mm. in diameter, height 35mm. Deepened into the shaft by 8mm. At the bottom, in the center, a nut on M4 is soldered and secured with a bolt from below.

Ready view. The base is oak 300x150x15mm.

Nameplate.

I was looking for a working scheme for a long time. I found it, but it was always connected with the fact that there was either a problem with the equipment or with the materials. I decided to make it like a crossbow. After looking at many options and wondering what I have in stock and what I can do myself on my equipment. The dimensions that I figured out right away, when the device was assembled, I did not like it. It turned out to be too wide. I had to shorten the cylinder bed. And put the flywheel on one bearing (on one pylon). Materials flywheel, connecting rods, counterweight, sealing washer, lamp and working cylinder bronze. Pylons, working piston, cylinder bed, cooler and washer with thread from the heat chamber aluminum. Flywheel shaft and displacer rod steel. Fire chamber stainless steel. Displacer graphite. And I put it on display, it's up to you to judge.

In which the working fluid (gaseous or liquid) moves in a closed volume, in fact it is a kind of external combustion engine. This mechanism is based on the principle of periodic heating and cooling of the working fluid. Extraction of energy occurs from the emerging volume of the working fluid. The Stirling engine works not only from the energy of burning fuel, but also from almost any source. This mechanism was patented by the Scotsman Robert Stirling in 1816.

The described mechanism, despite its low efficiency, has a number of advantages, first of all, it is simplicity and unpretentiousness. Thanks to this, many amateur designers make attempts to assemble a Stirling engine with their own hands. Some people succeed and some do not.

In this article we will consider Stirling with our own hands from scrap materials. We need the following blanks and tools: a tin can (it is possible from under the sprat), sheet metal, paper clips, foam rubber, elastic band, a bag, nippers, pliers, scissors, a soldering iron,

Now let's start assembling. Here is a detailed instruction on how to make a Stirling engine with your own hands. First you need to wash the jar, sand the edges. Cut a circle out of sheet metal so that it lies on the inner edges of the can. Determine the center (for this we use a caliper or ruler), make a hole with scissors. Next, we take a copper wire and a paper clip, straighten the paper clip, and make a ring at the end. We wind the wire on a paper clip - four tight turns. Next, use a soldering iron to punch through the resulting spiral with a small amount of solder. Then it is necessary to gently solder the spiral to the hole in the lid so that the stem turns out to be perpendicular to the lid. The paper clip should move freely.

After that, it is necessary to make a communicating hole in the lid. We make a displacer from foam rubber. Its diameter should be slightly less than the diameter of the can, but there should not be a large gap. The height of the displacer is a little more than half of the can. We cut out a hole for the sleeve in the center of the foam, the latter can be made of rubber or cork. We insert the stem into the resulting sleeve and glue everything. The displacer must be placed parallel to the cover, this is an important condition. Next, it remains to close the jar and solder the edges. The seam must be tight. Now we start making the working cylinder. To do this, we cut out a strip 60 mm long and 25 mm wide from the tin, bend the edge by 2 mm with pliers. We form a sleeve, after that we solder the edge, then it is necessary to solder the sleeve to the lid (above the hole).

Now you can start making the membrane. To do this, cut off a piece of film from the bag, push it a little with your finger inward, press the edges with an elastic band. Next, you need to check the correctness of the assembly. We heat the bottom of the can over a fire, pull the stem. As a result, the diaphragm should bend outward, and if the stem is released, the displacer should fall under its own weight, respectively, the diaphragm returns to its place. In the event that the displacer is made incorrectly or the soldering of the can is not tight, the stem will not return to its place. After that, we make the crankshaft and struts (the spacing of the cranks should be 90 degrees). The height of the cranks should be 7 mm, and the displacers should be 5 mm. The length of the connecting rods is determined by the position of the crankshaft. The end of the crank is inserted into the plug. So we examined how to assemble a Stirling engine with our own hands.

Such a mechanism will work from a conventional candle. If you attach magnets to the flywheel and take the coil of an aquarium compressor, then such a device can replace a simple electric motor. With your own hands, as you can see, it is not at all difficult to make such a device. There would be a desire.

You can, of course, buy beautiful factory models of Stirling engines, such as in this Chinese online store. However, sometimes you want to create yourself and make a thing, even from improvised means. On our website there are already several options for making these motors, and in this publication, check out a very simple option for making these motors at home.

Check out the 3 DIY options below.

Dmitry Petrakov, by popular demand, filmed step-by-step instructions for assembling a powerful Stirling engine, relative to its size and the amount of heat consumed. In this model, available to every viewer and common materials are involved - anyone can get them. All the sizes presented in this video were selected by the author on the basis of many years of experience with Stirlings of this design, and for this particular instance they are optimal.

In this model, available to every viewer and common materials are involved, thanks to which anyone can get them. All the sizes presented in this video were selected on the basis of many years of experience with Stirlings of this design, and for this particular instance they are optimal.

With feeling, sense and consistency.

Stirling motor in operation with load (water pump).

The water pump, assembled as a working prototype, is designed to work in tandem with Stirling motors. The peculiarity of the pump lies in the low consumption of energy required to perform its work: such a design uses only a small part of the dynamic internal working volume of the engine, and thus affects its performance to a minimum.

Stirling motor from a tin can

To make it, you will need materials at hand: a can of canned food, a small piece of foam rubber, a CD, two bolts and paper clips.

Foam rubber is one of the most common materials used in the manufacture of Stirling motors. An engine displacer is made from it. We cut out a circle from a piece of our foam rubber, make its diameter two millimeters less than the inner diameter of the can, and the height is slightly more than half of it.

In the center of the cover we drill a hole into which we then insert the connecting rod. For a smooth running of the connecting rod, we make a spiral from a paper clip and solder it to the cover.

We pierce the foam rubber circle in the middle with a screw and lock it with a washer from above and from below with a washer and a nut. After that, we attach a piece of paper clip by soldering, having previously straightened it.

Now we stick the displacer into the hole made in advance in the lid and tightly solder the lid and the jar. At the end of the paper clip we make a small loop, and in the lid we drill another hole, but slightly larger than the first.

We make a cylinder from tin using soldering.

We attach the finished cylinder to the jar using a soldering iron, so that there are no gaps left in the soldering point.

We make a crankshaft from a paper clip. The knee spacing should be done at 90 degrees. The knee, which will be 1-2 mm higher than the other in height above the cylinder.

We make racks for the shaft from paper clips. Making a membrane. To do this, we put on a plastic wrap on the cylinder, push it a little inward and fasten it to the cylinder with a thread.

The connecting rod, which will need to be attached to the membrane, is made from a paper clip and inserted into a piece of rubber. The length of the connecting rod must be made in such a way that at the bottom dead center of the shaft, the membrane is retracted into the cylinder, and at the highest, on the contrary, it is extended. We adjust the second connecting rod in the same way.

We glue the connecting rod with rubber to the membrane, and attach the other to the displacer.

We attach the paper clip legs to the jar with a soldering iron and attach the flywheel to the crank. For example, you can use a CD-ROM.

The Stirling engine is made at home. Now it remains to bring heat under the jar - to light a candle. And after a few seconds give a push to the flywheel.

How to make a simple Stirling engine (with photos and videos)

www.newphysicist.com

Let's make a Stirling engine.

A Stirling motor is a heat engine that works by cyclically compressing and expanding air or other gas (working fluid) at different temperatures, so that there is a clean conversion of thermal energy into mechanical work. More specifically, the Stirling engine is a closed-loop heat recuperative engine with a permanently gaseous working fluid.

Stirling engines are more efficient than steam engines and can reach 50% efficiency. They are also capable of quiet operation and can use almost any heat source. The heat source is generated outside the Stirling engine, not by internal combustion as is the case with Otto or diesel cycle engines.

Stirling engines are compatible with alternative and renewable energy sources, since they may become more significant as prices for conventional fuels rise, as well as in light of such problems as the depletion of oil reserves and changing of the climate.

In this project, we will give you simple instructions on how to create a very simple engine DIY Stirling using a test tube and syringe .

How to Make a Simple Stirling Engine - Video

Components and steps to make a Stirling motor

1. A piece of hardwood or plywood

This is the foundation for your engine. Thus, it must be rigid enough to cope with the movements of the engine. Then make three small holes as shown in the picture. You can also use plywood, wood, etc.

2. Marble or glass beads

In a Stirling engine, these balls have an important function. In this project, the marble acts as a hot air expellant from the warm side of the test tube to the cold side. When marble displaces hot air, it cools.

3. Sticks and screws

Studs and screws are used to hold the tube in a comfortable position for free movement in any direction without any interruption.

4. Rubber pieces

Buy an eraser and cut it into the following shapes. It is used to securely hold the tube and keep it sealed. There should be no leaks in the mouth of the tube. If so, the project will not be successful.

5. Syringe

The syringe is one of the most important and moving parts in a simple Stirling engine. Add a little grease to the inside of the syringe so that the piston can move freely inside the barrel. As the air expands inside the tube, it pushes the piston downward. As a result, the syringe barrel moves upward. At the same time, the marble rolls towards the hot side of the tube and displaces the hot air and makes it cool (reduce volume).

6. Test tube The test tube is the most important and working component of a simple Stirling engine. The tube is made of a certain type of glass (for example, borosilicate glass), which is highly heat-resistant. So it can be heated to high temperatures.

How does a Stirling engine work?

Some people say that Stirling engines are simple. If this is true, then just like the great equations of physics (like E = mc2), they are simple: on the surface they are simple, but richer, more complex and potentially very confusing until you realize them. I think it's safer to think of Stirling engines as complex: many very bad YouTube videos show how easy it is to “explain” them in a very incomplete and unsatisfactory way.

In my opinion, you cannot understand a Stirling engine by simply creating it or observing how it works from the outside: you need to seriously think about the cycle of steps it goes through, what happens to the gas inside, and how it differs from what happens in a conventional steam engine.

All that is required for the engine to operate is a temperature difference between the hot and cold parts of the gas chamber. Models have been built that can only operate with a temperature difference of 4 ° C, although factory engines are likely to operate with a difference of several hundred degrees. These engines can be the most efficient form of internal combustion engine.

Stirling engines and concentrated solar power

Stirling engines provide a neat method of converting thermal energy into motion that can power a generator. The most common arrangement is with the motor in the center of the parabolic mirror. The mirror will be mounted on the tracker to focus the sun's rays on the motor.

* Stirling engine as receiver

You may have played with convex lenses during your high school days. Concentrating solar energy to burn a sheet of paper or a match, am I right? New technologies are evolving day by day. Concentrated solar thermal energy is gaining more and more attention these days.

Above is a short video of a simple test tube motor using glass beads as a displacer and a glass syringe as a power piston.

This simple Stirling engine was built from materials that are available in most school science labs and can be used to demonstrate a simple heat engine.

Pressure-volume diagram per cycle

Process 1 → 2 Expansion of the working gas at the hot end of the tube, heat is transferred to the gas and the gas expands, increasing the volume and pushing the syringe plunger upward.

Process 2 → 3 As the marble moves towards the hot end of the test tube, the gas is forced out of the hot end of the test tube to the cold end, and as the gas moves, it gives off heat to the wall of the test tube.

Process 3 → 4 Heat is removed from the working gas and the volume decreases, the syringe plunger moves downward.

Process 4 → 1 Ends the cycle. The working gas moves from the cold end of the tube to the hot end as the marble balls displace it, drawing heat from the wall of the tube as it moves, thereby increasing the gas pressure.

The Stirling engine is a kind of engine that starts to work from thermal energy. In this case, the source of energy is completely unimportant. The main thing is that there is a difference in temperature conditions, in this case, such an engine will work. Now we will analyze how you can create a model of such a low-temperature engine from a can of Coca-Cola.

Materials and fixtures

Now we will analyze what we need to take to create an engine at home. What we need to take for stirling:

• Balloon.
• Three cans of cola.
• Special terminals, five pieces (for 5A).
• Bicycle spoke nipples (two pieces).
• Metal wool.
• A piece of steel wire thirty cm long and 1 mm in cross section.
• A piece of large steel or copper wire with a diameter of 1.6 to 2 mm.
• Wooden pin with a diameter of twenty mm (length one cm).
• Bottle cap (plastic).
• Electrical wiring (thirty cm).
• Special glue.
• Vulcanized rubber (about 2 centimeters).
• Fishing line (length thirty cm).
• Multiple balancing weights (eg nickel).
• CDs (three pieces).
• Special buttons.
• Tin can for creating a firebox.
• Heat resistant silicone and water cooled tin can.

Description of the creation process

Stage 1. Preparation of jars.

First, you should take 2 cans and cut off the top of them. If the tops are cut off with scissors, the resulting notches will have to be ground off with a file.

Stage 2. Manufacturing of the diaphragm.

As a diaphragm, you can take a balloon, which should be reinforced with vulcanized rubber. The ball must be cut and pulled over the jar. Then we glue a piece of special rubber onto the central part of the diaphragm. After the glue has set, in the center of the diaphragm, punch a hole for installing the wire. The easiest way to do this is with a special button that can be left in the hole until assembly.

Step 3. Cutting and creating holes in the lid.

Two holes of two mm must be made in the walls of the cover, they are necessary for installing the pivot axis of the levers. Another hole must be made in the bottom of the lid, a wire will go through it, which will be connected to the displacer.

At the last stage, the lid must be cut off. This is to prevent the displacer wire from snagging the edges of the cover. For such work, you can take household scissors.

Stage 4. Drilling.

In the jar, you need to drill two holes for the bearings. In our case, this was done with a 3.5 mm drill.

Stage 5. Manufacturing of the viewing window.

A special window must be cut in the engine housing. Now it will be possible to observe how all the components of the device work.

Stage 6. Modification of the terminals.

It is necessary to take the terminals and remove the plastic insulation from them. Then we take a drill and make through holes at the edges of the terminals. In total, you need to drill three terminals. Let's leave two terminals not drilled.

Stage 7. Creation of leverage.

As a material for the manufacture of levers, copper wire is taken, the diameter of which is only 1.88 mm. How exactly to bend the knitting needles is worth looking at on the Internet. You can take steel wire, just with copper wire, it is more convenient to work.

Stage 8. Manufacturing of bearings.

You will need two bicycle nipples to make the bearings. The diameter of the holes must be checked. The author drilled them through with a 2mm drill.

Step 9. Installing levers and bearings.

Levers can be placed directly through the viewing window. One end of the wire should be long with the flywheel resting on it. The bearings must be firmly seated in the right places. If there is any backlash, they can be glued.

Stage 10. Making a displacer.

The displacer is made of steel wool for polishing. To make the displacer, a steel wire is taken, a hook is created on it, and then a certain amount of cotton wool is wound on the wire. The displacer must be the same size so that it can easily move in the bank. The entire height of the displacer should not be more than five centimeters.

At the end on one side of the cotton wool it is necessary to make a spiral of wire so that it does not come out of the cotton wool, and on the second side we make a loop from the wire. Then we attach a fishing line to this loop, which will subsequently be pulled through the central part of the diaphragm. The vulcanized rubber should be in the middle of the container.

Step 11. Manufacturing the pressure vessel

It is necessary to cut the bottom of the jar in a certain way so that it remains about 2.5 cm from its base. The displacer together with the diaphragm must be moved into the reservoir. After that, this whole mechanism is transferred to the end of the can. The diaphragm needs to be pulled a little b so that it does not sag.

Then you need to take a terminal that has not been drilled and run a fishing line through it. The knot must be glued so that it does not move. The wire must be properly lubricated with oil and at the same time make sure that the displacer can easily pull the line behind it.

Stage 12. Manufacturing of push rods.

These special rods connect the diaphragm and levers. It is made from a piece of copper wire fifteen centimeters long.

Stage 13. Flywheel creation and installation

For the manufacture of a flywheel, we take three old CD-disks. Take a wooden rod as the center. After installing the flywheel, bend the crankshaft rod, so the flywheel will no longer fall off.

At the last stage, the entire mechanism is assembled completely.

The last step, creating the firebox

So we got to the last step in creating the engine.

Hello! Today I want to present to your attention a home-made engine that converts any temperature difference into mechanical work:

Stirling's engine- a heat engine, in which a liquid or gaseous working fluid moves in a closed volume, a kind of external combustion engine. It is based on periodic heating and cooling of the working fluid with the extraction of energy from the resulting change in the volume of the working fluid. It can work not only from fuel combustion, but also from any heat source.

I present to your attention my engine, made from pictures from the Internet:

Seeing this miracle, I had a desire to do it)) Moreover, there were many drawings and engine designs on the Internet. I will say right away: it is not difficult to do it, but it is a little problematic to regulate and achieve normal operation. It worked fine for me only from the third time (I hope you won't suffer so much)))).

Stirling engine working principle:

Everything is made from materials available to every brainchild:

Well, how can it be without sizes)))

The engine frame is made of staple wire. All fixed wire connections are brazed ()

The displacer (a disk that moves air inside the engine) is made of drawing paper and glued with superglue (it is hollow inside):

The smaller the clearance between the covers and the displacer in the upper and lower positions, the more efficient the engine will be.

The displacer stem - from the rivet (manufacturing: carefully pull out the inner part and, if necessary, clean it with sandpaper with a zero pad; glue the outer part to the upper "cold" lid with the cap inside). But this option has a drawback - there is no complete tightness and there is little friction, although a drop of engine oil will help get rid of it.

The piston cylinder is a neck from an ordinary plastic bottle:

The piston casing is made of a medical glove and secured with a thread, which after winding must be impregnated with superglue for reliability. A disc made of several layers of cardboard is glued to the center of the casing, on which a connecting rod is fixed.

The crankshaft is made of the same clips as the entire engine frame. the angle between the knees of the piston and the displacer is 90 degrees. Displacer working stroke - 5mm; piston - 8mm.

The flywheel consists of two CDs that are glued to a cardboard cylinder and mounted on the crankshaft axle.

So, stop talking nonsense, I present to you engine operation video:

The difficulties that I encountered were mainly related to excessive friction and the lack of exact dimensions of the structure. in the first case, a drop of engine oil and the centering of the crankshaft corrected the situation, then in the second, you had to rely on intuition))) But as you can see, everything worked out (though I completely reworked the engine 3 times))))

If you have any questions, write in the comments, we'll figure it out)))

The modern automotive industry has reached such a level of development that it is practically impossible to achieve fundamental improvements in the design of traditional internal combustion engines without fundamental scientific research. This situation forces designers to pay attention to alternative power plant designs... Some engineering centers have focused their efforts on creating and adapting to serial production of hybrid and electric models, while other automakers are investing in the development of engines powered by renewable sources of fuel (for example, biodiesel with rapeseed oil). There are other powertrain designs that could potentially become the new standard vehicle propulsion system.

Possible sources of mechanical energy for cars of the future include the external combustion engine, which was invented in the middle of the 19th century by the Scotsman Robert Stirling as a thermal expansion machine.

Scheme of work

A Stirling engine converts externally supplied thermal energy into useful mechanical work by changes in the temperature of the working fluid(gas or liquid) circulating in a closed volume.

In general, the scheme of operation of the device looks like this: in the lower part of the engine, the working substance (for example, air) heats up and, increasing in volume, pushes the piston upward. Hot air enters the top of the motor where it is cooled by the radiator. The pressure of the working fluid decreases, the piston is lowered for the next cycle. In this case, the system is sealed and the working substance is not consumed, but only moves inside the cylinder.

There are several options for the design of power units using the Stirling principle.

Stirling modification "Alpha"

The engine consists of two separate power pistons (hot and cold), each located in its own cylinder. Heat is supplied to the hot piston cylinder and the cold cylinder is located in the cooling heat exchanger.

Stirling modification "Beta"

The cylinder containing the piston is heated on one side and cooled on the opposite end. A power piston and a displacer move in the cylinder to change the volume of the working gas. The reverse movement of the cooled working substance into the hot cavity of the engine is performed by the regenerator.

Stirling modification "Gamma"

The design consists of two cylinders. The first is completely cold, in which the power piston moves, and the second, hot on one side and cold on the other, serves to move the displacer. The regenerator for circulation of cold gas can be common to both cylinders or be part of the displacer design.

Stirling engine advantages

Like most external combustion engines, Stirling has multi-fuel: the engine runs on temperature fluctuations, whatever the cause.

Interesting fact! Once a plant was demonstrated that operated on twenty fuel options. Without stopping the engine, gasoline, diesel fuel, methane, crude oil and vegetable oil were fed into the external combustion chamber - the power unit continued to operate steadily.

The engine has simplicity of design and does not require additional systems and attachments (timing, starter, gearbox).

The features of the device guarantee a long service life: more than one hundred thousand hours of continuous operation.

The Stirling engine is silent, since there is no detonation in the cylinders and there is no need to remove exhaust gases. The Beta version, equipped with a rhombic crank mechanism, is a perfectly balanced system that does not have vibrations during operation.

No processes occur in the engine cylinders that can have a negative impact on the environment. By choosing a suitable heat source (e.g. solar energy) Stirling can be absolutely environmentally friendly power unit.

Disadvantages of Stirling's design

With all the set of positive properties, the immediate mass use of Stirling engines is impossible for the following reasons:

The main problem lies in the material consumption of the structure. Cooling the working fluid requires large-volume radiators, which significantly increases the size and metal consumption of the installation.

The current technological level will allow the Stirling engine to compare in performance with modern gasoline engines only through the use of complex types of working fluid (helium or hydrogen) under a pressure of more than one hundred atmospheres. This fact raises serious questions both in the field of materials science and in ensuring the safety of users.

An important operational problem is related to the issues of thermal conductivity and temperature resistance of metals. Heat is supplied to the working volume through heat exchangers, which leads to inevitable losses. In addition, the heat exchanger must be made of high-pressure, heat-resistant metals. Suitable materials are very expensive and difficult to process.

The principles of changing the modes of the Stirling engine are also radically different from the traditional ones, which requires the development of special control devices. So, to change the power, it is necessary to change the pressure in the cylinders, the phase angle between the displacer and the power piston, or to influence the capacity of the cavity with the working fluid.

One of the ways to control the speed of rotation of the shaft on the model of the Stirling engine can be seen in the following video:

Efficiency

In theoretical calculations, the efficiency of a Stirling engine depends on the temperature difference of the working fluid and can reach 70% or more in accordance with the Carnot cycle.

However, the first samples realized in metal had an extremely low efficiency for the following reasons:

• ineffective options for the coolant (working fluid) that limit the maximum heating temperature;
• energy losses due to friction of parts and thermal conductivity of the motor housing;
• lack of construction materials resistant to high pressure.

Engineering solutions are constantly improving the structure of the power unit. So, in the second half of the XX century, a four-cylinder automobile Stirling engine with rhombic drive showed 35% efficiency in tests on a water coolant with a temperature of 55 ° C. Careful study of the design, the use of new materials and fine-tuning of the working units ensured the efficiency of the experimental samples of 39%.

Note! Modern gasoline engines of similar power have an efficiency of 28-30%, and turbocharged diesels in the range of 32-35%.

Modern examples of the Stirling engine, such as that created by the American company Mechanical Technology Inc, demonstrate efficiency up to 43.5%. And with the development of the production of heat-resistant ceramics and similar innovative materials, it will be possible to significantly increase the temperature of the working environment and achieve an efficiency of 60%.

Examples of successful implementation of automotive Stirlings

Despite all the difficulties, many workable models of the Stirling engine are known that are applicable to the automotive industry.

Interest in a Stirling suitable for installation in a car appeared in the 50s of the XX century. Such concerns as Ford Motor Company, Volkswagen Group and others were working in this direction.

UNITED STIRLING (Sweden) has developed a Stirling, in which the serial components and assemblies produced by automakers (crankshaft, connecting rods) were used to the maximum. The resulting four-cylinder V-engine had a specific gravity of 2.4 kg / kW, which is comparable to that of a compact diesel. This unit was successfully tested as a power plant for a seven-ton cargo van.

One of the successful examples is the four-cylinder Stirling engine of the Dutch production model "Philips 4-125DA", intended for installation in a passenger car. The engine had a working power of 173 liters. with. in sizes similar to the classic gasoline unit.

Significant results were achieved by engineers of the General Motors company, having built in the 70s an eight-cylinder (4 working and 4 compression cylinders) V-shaped Stirling engine with a standard crank mechanism.

A similar power plant in 1972 equipped with a limited edition of Ford Torino vehicles, the fuel consumption of which has decreased by 25% compared to the classic gasoline V-shaped eight.

Currently, more than fifty foreign companies are working to improve the design of the Stirling engine in order to adapt it to mass production for the needs of the automotive industry. And if it is possible to eliminate the disadvantages of this type of engine, at the same time preserving its advantages, then it is Stirling, and not turbines and electric motors, that will replace the gasoline internal combustion engine.

Supplanted other types of power plants, however, the work aimed at abandoning the use of these units suggests an imminent change in leading positions.

Since the beginning of technological progress, when the use of engines that burn fuel inside was just beginning, their superiority was not obvious. The steam engine, as a competitor, contains a lot of advantages: along with the traction parameters, it is silent, omnivorous, easy to operate and configure. But lightness, reliability and economy allowed the internal combustion engine to take over steam.

Today, issues of ecology, economy and safety are at the forefront. This forces engineers to throw their energy on mass-produced units powered by renewable fuels. In the 16th year of the nineteenth century, Robert Stirling registered an external heat engine. Engineers believe that this unit is capable of replacing the modern leader. The Stirling engine combines efficiency, reliability, runs quietly, on any fuel, this makes the product a player in the automotive market.

Robert Stirling (1790-1878):

History of the Stirling engine

The plant was originally designed to replace a steam-powered machine. Steam machinery boilers exploded when the pressure exceeded the permissible standards. From this point of view, Stirling is much safer, it functions using temperature differences.

The principle of operation of the Stirling engine is in the alternate supply or removal of heat from the substance on which the work is done. The substance itself is enclosed in a closed volume. The role of the working substance is performed by gases or liquids. There are substances that play the role of two components, the gas is converted to liquid and vice versa. The Stirling liquid piston motor has: small dimensions, powerful, generates high pressure.

The decrease and increase in the volume of gas during cooling or heating, respectively, is confirmed by the law of thermodynamics, according to which all components: the degree of heating, the amount of space occupied by the substance, the force acting per unit area, are related and described by the formula:

P * V = n * R * T

• P is the force of action of the gas in the engine per unit area;
• V is the quantitative value occupied by the gas in the engine space;
• n is the molar amount of gas in the engine;
• R is the gas constant;
• T is the degree of gas heating in the engine K,

Stirling engine model:

Due to the unpretentiousness of installations, engines are divided into: solid fuel, liquid fuel, solar energy, chemical reaction and other types of heating.

Cycle

Stirling's external combustion engine uses a combination of phenomena of the same name. The effect of the ongoing action in the mechanism is high. Thanks to this, it is possible to design an engine with good performance within the normal size.

It should be borne in mind that the design of the mechanism provides for a heater, refrigerator and regenerator, a device for removing heat from the substance and returning heat at the right time.

Ideal Stirling cycle, (temperature-volume diagram):

Ideal circular phenomena:

• 1-2 Change in the linear dimensions of a substance with a constant temperature;
• 2-3 Heat removal from the substance to the heat exchanger, the space occupied by the substance constantly;
• 3-4 Forced reduction of the space occupied by the substance, the temperature is constant, heat is removed to the cooler;
• 4-1 Forced increase in the temperature of the substance, the occupied space is constant, heat is supplied from the heat exchanger.

Ideal Stirling cycle, (pressure-volume diagram):

From the calculation (mol) of the substance:

Heat input:

Heat received by the cooler:

The heat exchanger receives heat (process 2-3), the heat exchanger gives off heat (process 4-1):

R - Universal gas constant;

СV - the ability of an ideal gas to retain heat at a constant amount of occupied space.

Due to the use of a regenerator, part of the heat remains, as the energy of the mechanism, which does not change for passing circular phenomena. The refrigerator receives less heat, thus the heat exchanger saves heat from the heater. This increases the efficiency of the installation.

Efficiency of a circular phenomenon:

ɳ =

It is noteworthy that without a heat exchanger, the set of Stirling processes is feasible, but its efficiency will be much lower. Running a set of processes backwards leads to a description of the cooling mechanism. In this case, the presence of a regenerator is a prerequisite, since during the passage of (3-2) it is impossible to heat the substance from the cooler, the temperature of which is much lower. It is also impossible to give off heat to the heater (1-4), the temperature of which is higher.

How the engine works

To understand how the Stirling engine works, we will understand the structure and frequency of the unit's phenomena. The mechanism converts the heat received from the heater outside the product into a force on the body. The whole process takes place due to the temperature difference in the working substance, which is in a closed circuit.

The principle of operation of the mechanism is based on expansion due to heat. Immediately before expansion, the substance in a closed loop heats up. Accordingly, the substance is cooled before being compressed. The cylinder itself (1) is wrapped in a water jacket (3), heat is supplied to the bottom. The piston doing the work (4) is placed in a sleeve and sealed with rings. Between the piston and the bottom there is a displacement mechanism (2), which has significant clearances and moves freely. The substance in a closed loop moves through the volume of the chamber due to the displacer. The movement of the substance is limited in two directions: the bottom of the piston, the bottom of the cylinder. The movement of the displacer is provided by the rod (5), which passes through the piston and operates by an eccentric with a 90 ° delay in comparison with the piston drive.

• Position "A":

The piston is located in the lowest position, the substance is cooled by the walls.

• Position "B":

The displacer occupies the upper position, moving, passes the substance through the end slots to the bottom, and cools itself. The piston is stationary.

• Position "C":

The substance receives heat, under the influence of heat it increases in volume and raises the expander with the piston up. Work is done, after which the displacer sinks to the bottom, pushing out the substance and cooling.

• Position "D":

The piston goes down, compresses the cooled substance, useful work is done. The flywheel serves as an energy accumulator in the design.

The considered model does not have a regenerator; therefore, the efficiency of the mechanism is not high. The heat of the substance after completing the work is removed to the coolant using the walls. The temperature does not have time to decrease by the required amount, so the cooling time is prolonged, the motor speed is low.

Engine types

Structurally, there are several options using the Stirling principle, the main types are:

The design uses two different pistons placed in different circuits. The first circuit is used for heating, the second circuit is used for cooling. Accordingly, each piston has its own regenerator (hot and cold). The device has a good power-to-volume ratio. The disadvantage is that the temperature of the hot regenerator creates design difficulties.

• Β-Stirling engine:

The design uses one closed loop, with different temperatures at the ends (cold, hot). A piston with a displacer is located in the cavity. The displacer divides the space into a hot and cold zone. The exchange of cold and heat occurs by pumping the substance through a heat exchanger. Structurally, the heat exchanger is made in two versions: external, combined with a displacer.

• The γ-Stirling engine:

The piston mechanism provides for the use of two closed circuits: cold and with a displacer. Power is removed from the cold piston. A piston with a displacer is hot on one side and cold on the other. The heat exchanger is located both inside and outside the structure.

Some power plants are not similar to the main types of engines:

• Rotary Stirling engine.

Structurally, an invention with two rotors on the shaft. The part makes rotational movements in a closed cylindrical space. A synergistic approach to the implementation of the cycle has been laid. The body contains radial slots. Blades with a certain profile are inserted into the grooves. The plates are put on the rotor and can move along the axis when the mechanism rotates. All details create changing volumes with phenomena occurring in them. The volumes of the various rotors are connected by means of channels. The arrangement of the channels is offset by 90 ° to each other. The displacement of the rotors relative to each other is 180 °.

• Thermoacoustic Stirling engine.

The engine uses acoustic resonance to drive processes. The principle is based on the movement of a substance between a hot and cold cavity. The circuit reduces the number of moving parts, the difficulty in removing the received power and maintaining resonance. The design refers to the free piston type of the motor.

DIY Stirling engine

Today, quite often in the online store you can find souvenirs made in the form of the engine in question. Structurally and technologically, the mechanisms are quite simple, if desired, the Stirling engine can be easily constructed with your own hands from improvised means. A large number of materials can be found on the Internet: videos, drawings, calculations and other information on this topic.

Low Temperature Stirling Engine:

• Consider the simplest wave motor, which requires a tin can, soft polyurethane foam, disc, bolts, and paper clips. All these materials are easy to find at home, the following steps remain:
• Take a soft polyurethane foam and cut a circle two millimeters smaller than the inside diameter of the can. The foam is two millimeters more than half the height of the can. Foam rubber plays the role of a displacer in the engine;
• Take the lid of the jar, make a hole in the middle, two millimeters in diameter. Solder a hollow rod to the hole, which will act as a guide for the engine connecting rod;
• Take a circle cut out of foam, insert a screw into the middle of the circle and lock it on both sides. Solder a pre-straightened paper clip to the washer;
• Drill a hole two centimeters from the center, three millimeters in diameter, pass the displacer through the central hole of the lid, solder the lid to the jar;
• Make a small cylinder out of tin, one and a half centimeters in diameter, solder it to the lid of the can in such a way that the side hole of the lid is clearly centered inside the engine cylinder;
• Make the engine crankshaft out of a paper clip. The calculation is performed in such a way that the knee spacing is 90 °;
• Make a stand for the engine crankshaft. Make an elastic membrane of plastic film, put the film on the cylinder, push it, fix it;

• Make a connecting rod for the engine yourself, bend one end of the straightened product in the shape of a circle, insert the other end into a piece of eraser. The length is adjusted in such a way that at the lowest point of the shaft, the membrane is retracted, at the highest point, the membrane is extended as much as possible. Adjust the other connecting rod in the same way;
• Glue the rubber-tipped engine connecting rod to the membrane. Attach the connecting rod without a rubber tip to the displacer;
• Slide the flywheel from the disc onto the engine crank mechanism. Attach legs to the jar so as not to hold the product in your hands. The height of the legs allows you to place a candle under the jar.

After it was possible to make the Stirling engine at home, the engine is started. To do this, place a lighted candle under the jar, and after the jar has warmed up, give a push to the flywheel.

The considered installation option can be quickly assembled at home as a visual aid. If you set yourself the goal and desire to make the Stirling engine as close as possible to the factory counterparts, drawings of all parts are freely available. Step-by-step execution of each node will allow you to create a working layout that is no worse than the commercial versions.

Advantages

The Stirling engine has the following advantages:

• For the engine to work, a temperature difference is required, which fuel causes heating is not important;
• There is no need to use attachments and auxiliary equipment, the engine design is simple and reliable;
• The engine resource, due to the design features, is 100,000 operating hours;
• The operation of the engine does not create extraneous noise, since there is no detonation;
• The process of engine operation is not accompanied by the release of waste substances;
• Engine operation is accompanied by minimal vibration;
• The processes in the cylinders of the plant are environmentally friendly. Using the correct heat source will keep the engine "clean".

Flaws

The disadvantages of the Stirling engine include:

• It is difficult to establish mass production, since the engine structurally requires the use of a large amount of materials;
• High weight and large dimensions of the engine, since a large radiator must be used for effective cooling;
• To increase efficiency, the engine is boosted using complex substances (hydrogen, helium) as a working fluid, which makes the operation of the unit dangerous;
• The high temperature resistance of steel alloys and their thermal conductivity complicate the engine manufacturing process. Significant heat losses in the heat exchanger reduce the efficiency of the unit, and the use of specific materials makes the engine expensive to manufacture;
• To adjust and switch the engine from mode to mode, it is necessary to use special control devices.

Usage

The Stirling engine has found its niche and is actively used where dimensions and omnivorousness are an important criterion:

• Stirling engine-electric generator.

The mechanism for converting heat into electrical energy. Often there are products used as portable tourism generators, solar energy installations.

• The engine is like a pump (electrical).

The engine is used for installation in a heating system circuit, saving on electrical energy.

• The engine is like a pump (heater).

In countries with warm climates, the engine is used as a space heater.

Submarine Stirling engine:

• The engine is like a pump (cooler).

Almost all refrigerators in their design use heat pumps, installing a Stirling engine saves resources.

• The engine is like a pump that generates ultra-low heat ratios.

The device is used as a refrigerator. To do this, the process is started in the opposite direction. The units liquefy the gas, cool the measuring elements in precision mechanisms.

• Underwater engine.

Submarines in Sweden and Japan are powered by an engine.

Stirling engine as a solar power plant:

• The engine is like an energy accumulator.

Fuel in such units, molten salt, and the engine are used as a source of energy. The motor is ahead of chemical elements in terms of energy storage.

• Solar engine.

Converting the sun's energy into electricity. The substance in this case is hydrogen or helium. The engine is placed in the focus of the maximum concentration of the sun's energy generated by the parabolic antenna.

The Stirling engine, once famous, was forgotten for a long time due to the widespread use of another engine (internal combustion). But today we hear more and more about him. Maybe he has a chance to become more popular and find his place in a new modification in the modern world?

History

The Stirling engine is a heat engine that was invented in the early nineteenth century. The author, as you know, was a certain Stirling named Robert, a priest from Scotland. The device is an external combustion engine, where the body moves in a closed container, constantly changing its temperature.

Due to the proliferation of another type of motor, it was almost forgotten. Nevertheless, thanks to its advantages, today the Stirling engine (many amateurs build it at home with their own hands) is making a comeback again.

The main difference from an internal combustion engine is that heat energy comes from the outside, and is not generated in the engine itself, as in an internal combustion engine.

Principle of operation

You can imagine a closed air volume enclosed in a housing with a membrane, that is, a piston. When the body heats up, the air expands and does work, thus bending the piston. Then it cools down and it bends in again. This is the cycle of the mechanism.

It is no wonder that many do-it-yourself Stirling thermoacoustic engines are made at home. Tools and materials for this require the very minimum that can be found in everyone's house. Let's look at two different ways to create it easily.

Materials for work

To make a Stirling engine with your own hands, you will need the following materials:

• tin;
• steel spoke;
• brass tube;
• hacksaw;
• file;
• wooden stand;
• scissors for metal;
• fasteners details;
• soldering iron;
• soldering;
• solder;
• machine.

It's all. The rest is a matter of simple technique.

How to make

A firebox and two cylinders for the base are prepared from tin, of which the Stirling engine, made by hand, will consist. The dimensions are selected independently, taking into account the purposes for which this device is intended. Let's assume the motor is being made for demonstration purposes. Then the master cylinder sweep will be from twenty to twenty-five centimeters, no more. The rest of the parts should adjust to it.

On the top of the cylinder for the movement of the piston, two protrusions and holes with a diameter of four to five millimeters are made. The elements will act as bearings for locating the crank assembly.

Next, they make the working fluid of the motor (ordinary water will become it). Tin circles are soldered to the cylinder, which is rolled up into a pipe. Holes are made in them and brass tubes are inserted from twenty-five to thirty-five centimeters in length and four to five millimeters in diameter. At the end, they check how tight the chamber has become by flooding it with water.

Next comes the displacer. For manufacturing, take a blank from a tree. On the machine, they are trying to make it take the shape of a regular cylinder. The displacer should be slightly smaller than the cylinder diameter. The optimum height is selected after the do-it-yourself Stirling engine is made. Therefore, at this stage, the length should assume some margin.

The spoke is turned into a cylinder rod. A hole is made in the center of the wooden container, suitable for the stem, insert it. In the upper part of the stem, it is necessary to provide a place for the connecting rod device.

Then they take tubes of copper four and a half centimeters long and two and a half centimeters in diameter. A tin mug is soldered to the cylinder. A hole is made on the sides of the walls for communication of the container with the cylinder.

The piston is also fitted on a lathe to the inside of the large cylinder. At the top, the stem is connected in a hinged way.

The assembly is completed and the mechanism is set up. To do this, the piston is inserted into a larger cylinder and connected to another smaller cylinder.

A crank mechanism is built on a large cylinder. Part of the engine is fixed with a soldering iron. The main parts are fixed on a wooden base.

The cylinder is filled with water and a candle is placed under the bottom. The Stirling engine, made by hand from start to finish, is checked for operability.

Method two: materials

The engine can be made in another way. To do this, you will need the following materials:

• tin;
• foam rubber;
• paper clips;
• disks;
• two bolts.

How to make

Foam rubber is very often used to make a simple, not powerful Stirling engine at home with your own hands. A displacer for the motor is prepared from it. Cut out the foam circle. The diameter should be slightly smaller than that of a tin can, and the height should be just over half.

A hole is made in the center of the cover for the future connecting rod. To make it walk smoothly, the paper clip is rolled into a spiral and soldered to the lid.

The foam rubber circle in the middle is pierced with a thin wire with a screw and fixed on top with a washer. Then a piece of paper clip is connected by soldering.

The displacer is pushed into the hole in the lid and the jar and lid are soldered together to seal. A small loop is made on a paper clip, and another, larger hole in the lid.

The tin sheet is rolled up into a cylinder and soldered, and then attached to the jar so that there are no gaps left at all.

The paper clip is turned into a crankshaft. The spacing should be exactly ninety degrees. The knee above the cylinder is made slightly larger than the other.

The rest of the staples are converted into shaft racks. The membrane is made as follows: the cylinder is wrapped in a polyethylene film, pressed through and fastened with a thread.

The connecting rod is made from a paper clip that is inserted into a piece of rubber and the finished part is attached to the membrane. The length of the connecting rod is made such that the membrane is pulled into the cylinder at the bottom gross point, and stretched out at the highest point. The second part of the connecting rod is made in the same way.

Then one is glued to the membrane and the other to the displacer.

The jar legs can also be made from paper clips and soldered. A CD is used for the crank.

So the whole mechanism is ready. It remains only to substitute and light a candle under it, and then give a push through the flywheel.

Conclusion

Such is the low-temperature Stirling engine (self-built). Of course, on an industrial scale, such devices are manufactured in a completely different way. However, the principle remains unchanged: the air volume is heated and then cooled. And this is constantly repeated.

Finally, look at these drawings of the Stirling engine (you can do it yourself without special skills). Maybe you are already on fire with the idea, and you would like to do something similar?

A Stirling engine is a heat engine in which a working fluid, in the form of a gas or liquid, moves in a closed volume, a kind of external combustion engine. It is based on periodic heating and cooling of the working fluid with the extraction of energy from the resulting change in the volume of the working fluid. It can work not only from fuel combustion, but also from any heat source.

A heat engine, in which the working fluid, in the form gas or liquid, moves in a closed volume, a kind of external combustion engine.

based on periodic heating and cooling of the working fluid with the extraction of energy from the resulting change in the volume of the working fluid. It can work not only from fuel combustion, but also from any heat source.

Rice. 1. Stirling engine

@ https://dvigyn.com/?p=1032

In the 19th century, engineers wanted to create a safe replacement for the steam engines of the time, whose boilers often exploded due to high steam pressures and inappropriate materials for their construction. A good option came with the creation Stirling engine that could convert any temperature difference into work.

It was first patented by Scottish priest Robert Stirling on September 27, 1816 (English patent No. 4081). However, the first elementary “ engines hot air ”were known at the end of the 17th century, long before Stirling. Stirling's achievement is the addition of a node he calls "economy". In modern scientific literature, this unit is called a "regenerator". It increases the performance of the engine by trapping heat in the warm part of the engine while the working fluid is cooled. This process greatly improves the efficiency of the system. Most often, the regenerator is a chamber filled with wire, granules, corrugated foil (corrugations go along the direction of the gas flow).

The principle of operation of the Stirling engine:

Basic principle of work Stirling engine consists in constantly alternating heating and cooling of the working fluid, for example, gas, in a closed cylinder.

It is known that when a gas is heated, its volume increases, and when it cools, it decreases. This property of gases is the basis of the work Stirling engine.

Uses the Stirling cycle, which is not inferior to the Carnot cycle in terms of thermodynamic efficiency, and even has an advantage. The fact is that the Carnot cycle consists of little different isotherms and adiabats. The practical implementation of this cycle is not very promising. The Stirling cycle made it possible to obtain a practical engine in an acceptable size.

Rice. 2. The "pressure-volume" diagram of the idealized Stirling cycle

The Stirling cycle consists of four phases and is separated by two transitional phases:

– heat,

– extension,

– transition to the source of cold,

– cooling,

– compression

– and transition to a heat source.

Thus, when passing from a warm source to a cold source, the gas in the cylinder expands and contracts. At the same time, the pressure changes, due to which useful work can be obtained.

Heating and cooling of the working fluid (sections 4 and 2) is performed by the displacer. Ideally, the amount of heat given off and taken away by the displacer is the same. Useful work is performed only due to isotherms, that is, it depends on the temperature difference between the heater and the cooler, as in the Carnot cycle.

Work cycle Stirling engine beta type (the most common) looks like this:

Rice. 2. The duty cycle of the Stirling engine

@ https://ru.wikipedia.org/wiki/Stirling_Engine

where: a - displacement piston; b - working piston; c - flywheel; d - fire (heating area); e - cooling fins (cooling area).

1. An external heat source heats the gas at the bottom of the heat exchanger cylinder. The generated pressure pushes the working piston upward (note that the displacement piston does not fit snugly against the walls).

2. The flywheel pushes the displacement piston downward, thereby transferring the heated air from the bottom to the cooling chamber.

3. The air cools and contracts, the working piston goes down.

4. The displacement piston moves upward, thereby moving the cooled air to the bottom. And the cycle repeats itself.

IN Stirling's car the movement of the working piston is shifted by 90 ° relative to the movement of the displacement piston. Depending on the sign of this shift, the machine can be a motor or a heat pump. At 0 ° shift, the machine does not perform any work (other than frictional losses) and does not generate it.

Stirling engine advantages:

- "omnivorous" engine. A Stirling engine can operate on almost any temperature difference: for example, between different layers of water in the ocean, from the sun, from a nuclear or isotope heater, a coal or wood stove, etc.,

– simplicity of design - design engine very simple, it does not require additional systems such as a gas distribution mechanism. It starts on its own and does not need a starter,

- increased resource - simplicity of design, the absence of many "delicate" units allows the Stirling engine to provide an unprecedented operational reserve for other engines in tens and hundreds of thousands of hours of continuous operation,

- efficiency - for the utilization of certain types of thermal energy, especially with a small temperature difference, engines Stirling engines often turn out to be the most efficient types of engines. For example, in the case of converting solar energy into electricity, "stirlings" sometimes give higher efficiency (up to 31.25%) than heat engines for a couple,

- environmental friendliness - "styling" has no exhaust, which means its noise level is much lower than that of piston engines internal combustion. Beta-styling with a rhombic mechanism is a perfectly balanced device and, with a sufficiently high quality of workmanship, has an extremely low vibration level (vibration amplitude less than 0.0038 mm). By itself, "styling" does not have any parts or processes that can contribute to environmental pollution. It does not consume the working fluid. The environmental friendliness of the engine is primarily due to the environmental friendliness of the heat source,

- efficiency engine Stirling is up to 45%.

Stirling engine configuration and design:

There are several configurations engine Stirling:

- alpha-Stirling- contains two separate power pistons in separate cylinders, one is hot, the other is cold. A cylinder with a hot piston is in a heat exchanger with a higher temperature, with a cold one in a colder one.

Rice. 3.α-Stirling

@ https://ru.wikipedia.org/wiki/Stirling_Engine

This species engine the power-to-volume ratio is quite high, but, unfortunately, the high temperature of the "hot" piston creates certain technical difficulties. The regenerator is located between the hot part of the connecting tube and cold,

- beta Stirling- there is only one cylinder, hot at one end and cold at the other. A piston (from which power is removed) and a displacer move inside the cylinder, separating the hot and cold cavities.

Rice. 4. β-Stirling

@ https://ru.wikipedia.org/wiki/Stirling_Engine

The gas is pumped from the cold to the hot end of the cylinder through the regenerator. The regenerator can be external, as part of the heat exchanger, or it can be combined with a displacement piston,

- gamma-Stirling- there is also a piston and a displacer, but at the same time there are two cylinders - one cold (the piston moves there, from which power is removed), and the second is hot from one end and cold from the other (the displacer moves there).

Rice. 5. γ-Stirling

@ https://ru.wikipedia.org/wiki/Stirling_Engine

The regenerator can be external, in this case it connects the hot part of the second cylinder with the cold one and simultaneously with the first (cold) cylinder. The internal regenerator is part of the displacer.

Application of Stirling engine:

Applicable in cases where a small converter is needed thermal energy, simple in design, or when the efficiency of other thermal engines turns out to be lower, for example, if the temperature difference is not enough for the operation of a steam or gas turbine:

– universal sources of electricity,

– pumps,

– heat pumps,

– refrigeration equipment.