Principle of operation
The proposed innovative technology is based on the use of a highly efficient four-cylinder engine external combustion. This is a thermal engine. Heat can be supplied from an external heat source or produced by burning a wide range of fuels inside the combustion chamber.
Heat is maintained at a constant temperature in one engine compartment, where it is converted to hydrogen under pressure. Expanding, hydrogen pushes the piston. In the low temperature of the engine, the hydrogen is cooled with heat batteries and liquid coolers. With expansion and compression, hydrogen causes a return-translational movement of the piston, which is converted into a rotational movement using an inclined washer, which actuates the standard, capacitive electrical generator. In the process of cooling hydrogen, heat is also produced, which can be used for the combined production of electricity and heat in the auxiliary processes.
general description
Thermal power plant FX-38 is a single "engine generator" module, which includes an external combustion engine, a combustion system running on propane, natural gas, passing oil gas, other types of fuel with medium and low energy intensity (biogas), inductive generator, The engine control system, protected from atmospheric influences body with a built-in ventilation system and other auxiliary equipment for parallel working with a high voltage network.
Rated power for electricity when working on natural gas or biogas at a frequency of 50 Hz is 38 kW. In addition, the installation produces 65 kWh extra heat from the combined heat and electricity production system supplied to a special order.
Installation FX-38 can be equipped with various cooling system options to ensure the flexibility of the installation scheme. The product is designed for a simple connection to electrical contacts, fuel supply systems and external cooling system pipes, if equipped with such.
Additional details and options
- Power Measurement Module (provides a set current transformer to read on the display of variable current parameters)
- RS-485 remote monitoring option
- Options for built-in or remotely mounted radiator
- Option of using propane fuel
- Option of using natural gas
- Option of using associated petroleum gas
- Low energy intensity fuel use option
The FX-48 installation can be used in several embodiments as follows:
- Parallel connection to high-voltage network at 50 Hz, 380 V AC
- Mode of co-generation of heat and electricity
Operating characteristics of the installation
In the production of electricity and heat production at a frequency of 50 Hz, the installation produces 65 kW-h extra heat. The product is equipped with a system of pipes, ready to connect to the type of liquid / liquid supplied by the customer. The hot side of the heat exchanger is a closed loop with an engine cooler and an integrated system radiator, if any. The cold side of the heat exchanger is designed for the Customer's heat transfer circuit.
Maintenance
Installation is designed for continuous operation and power take-off. Basic check performance characteristics It is carried out by the customer with an interval of 1000 hours and includes checking the water cooling system and oil level. After 10,000 hours of operation, the front of the installation is maintained, including the replacement of the piston ring, the rod glance, the drive belt and various seals. Specific key components are checked for wear. The engine speed is 1,500 revolutions per minute to work at a frequency of 50 Hz.
Uninterrupted
The uninterrupted operation of the installation is over 95%, based on the operating intervals, and is taken into account during the schedule maintenance.
Sound pressure level
The level of sound pressure of the unit without a built-in radiator is 64 dBa at a distance of 7 meters. The sound pressure level of the block with an integrated radiator with cooling fans is 66 dBA at a distance of 7 meters.
Emissions
When working on natural gas, the engine emissions are less than or equal to 0.0574 g / nm 3 NO x, 15.5 g / nm 3 volatile organic compounds and 0.345 g / nm 3 CO.
Gaseous fuel
The engine is designed to work on different types Gaseous fuel with the lower heat of combustion from 13.2 to 90.6 MJ / nm 3, associated petroleum gas, natural gas, coal methane, recycling gas, propane and biogas polygons of MSW. To cover this range, the device can be ordered with the following fuel system configurations:
Combustion system requires adjustable pressure Gas supply to 124-152 mbar for all types of fuel.
Environment
Installation in standard version operates at ambient temperature from -20 to + 50 ° C.
Installation Description
Thermal power plant FX-38 is fully ready for electricity generation in factory supplies. The built-in electrical panel is mounted on the block to meet the requirements of the interface and control. The digital display-resistant digital display, built into the electrical console, provides the operator to the launch, stop and restarting interface using the buttons. The electrical console also serves as the main location for connecting the terminal electrical device of the customer, as well as with wired terminal terminals.
The installation is capable of reaching the output power of the full load by about 3-5 minutes from the moment of starting depending on the initial temperature of the system. The start and installation sequence is activated by pressing the button.
After the start command, the installation connects to the high voltage network by closing the internal contactor to the network. The engine is immediately rotated by cleaning the combustion chamber to open the fuel valves. After opening the fuel valve, the energy is fed to the ignition device, filling in fuel in the combustion chamber. The existence of incineration is determined by increasing the temperature of the working gas, which results in the procedure for controlling overclocking to the operating temperature point. After that, the flame remains self-sustaining and constant.
After the setup command, the fuel valve is first closed to stop the burning process. After a pre-set time, during which the mechanism is cooled, the contactor will open, turning off the installation from the network. In the event that such installed, the radiator fans can operate for some time to reduce the coolant temperature.
Installation uses an external combustion engine with a constant stroke length connected to a standard induction generator. The device works in parallel with the high-voltage network or in parallel with the energy distribution system. The induction generator does not create its own excitation: it gets excited from the connected source of the power supply. If the voltage in the power grid disappears, the installation is turned off.
Description of installation nodes
The installation design provides its simple installation and connection. There are external compounds for fuel pipes, terminal devices of electricity, interfaces of communications and, if provided, an external radiator and a heat exchanger pipe system liquid / liquid. Installation can be enabled with a built-in or remotely mounted radiator and / or heat exchanger pipe system liquid / liquid for engine cooling. Also provided tools for safe shutdown and logic control circuits, designed specifically for the desired mode of operation.
The casing has two operational panels on each side of the engine / generator separation and an external one-strain door to access the electrical compartment.
Installation weight: about 1770 kg.
The engine is a 4-cylinder (260 cm 3 / cylinder) an external combustion engine absorbing the heat of continuous combustion of gas fuel in the chamber internal combustionand includes the following built-in components:
- Air supply fan into the combustion chamber is driven by the engine
- Air filter Cameras combustion
- Fuel system and casing combustion chamber
- Pump for lubricant oilis driven by the engine
- Cooler and filter for lubricating oil
- Water pump engine cooling system, drives the engine
- Temperature sensor water in the cooling system
- Lubricating oil pressure sensor
- Gas pressure and temperature sensor
- All necessary control and protective equipment
The characteristics of the generator are below:
- Rated power of 38 kW at 50 Hz, 380 V AC
- Electric efficiency 95.0% with power factor 0.7
- Excitation from the municipal power grid using an induction motor / generator causative agent
- Less than 5% of total harmonic distortions from the lack of load until full load
- Class of insulation F.
Operator Interface - Digital Display Provides installation control. The operator can start and stop the installation from a digital display, watch the opening hours, work data and warnings / failures. When installing an optional power measurement module, the operator can see many electrical parameters, such as generated power, kilowatt clock, kilowatt-amps and power factor.
The equipment diagnostics and data collection feature is built into the installation control system. Diagnostic information simplifies the remote data collection, the data report and troubleshooting of the device. These functions include collecting system data, such as working status information, all mechanical operating parameters, such as temperature and pressure of cylinders, as well as if an optional power meter is connected, the electrical parameters of the values \u200b\u200bof the power generated. Data can be transmitted via the standard RS-232 connection port and are shown on a personal computer or laptop using software To collect data. For multiple installations or in cases where the signal transmission distance exceeds the capabilities of the RS-232, the RS-485 option is used to obtain data using the Modbus RTU protocol.
To transfer hot exhaust gases From the combustion system uses stainless steel pipes. A balanced exhaust damper with a protective cap from rain and snow is attached to the exhaust pipe at the exhaust of the casing.
For cooling, various application technologies and configurations can be applied:
Built-in radiator - provides a radiator, calculated on the ambient temperature to + 50 ° C. All pipes are connected in the factory. This is a typical technology if the waste heat disposal is not used.
The external radiator is intended for installation by the customer, it is designed for the ambient temperature to + 50 ° C. Short bearing legs come with a radiator for mounting on the contact table. If it is necessary to install in the room, you can use this option instead of providing the ventilation system required to supply cooling air into a built-in radiator.
External cooling system - provides a pipe system outside the casing for the cooling system supplied by the customer. It can be a heat exchanger or remotely mounted radiator.
The refrigerant consists of 50% water and 50% of ethylene glycol in volume: it can be replaced with a mixture of propylene glycol and water, if necessary.
Installation FX-38 uses hydrogen as a working fluid to drive the motion of engines due to high hydrogen abilities to heat transfer. In the normal mode of operation, a predictable amount of hydrogen is consumed due to normal leaks caused by the permeability of the material. To account for this pace of consumption, the installation location requires one or more sets of cylinders with hydrogen, adjusted and connected to the block. Inside the installation, the built-in hydrogen compressor increases the pressure in the cylinder to a higher pressure in the engine and introduces small portions upon request of the built-in software. The built-in system does not require maintenance, and cylinders are subject to replacement depending on the engine operation.
For fuel supply, a pipe with standard pipe thread is supplied with a standard pipe thread for all standard fuel types, with the exception of low-energy options for which the standard pipe thread 1 1/2 inches. Fuel pressure requirements for all types of fuel gaseous fuels range from 124 to 152 mbar.
This is an introductory part of the cycle of the dedicated articles Internal combustion engine, which is brief excursion In history, telling about the evolution of the DVS. Also, the article will be affected by the first cars.
The following parts will describe in detail various DVS:
Row-piston
Rotor
Turboactive
Jet
The engine was installed on a boat that was able to rise upstream of the Sona River. A year later, after the test, the brothers received a patent for their invention, signed by Napoleon Bonopart, for a period of 10 years.
It would be more correct to call this engine with reactive, since his work was to pushing the water from the pipe located under the bottom of the boat ...
The engine consisted of a ignition chamber and combustion chamber, air bellows, fuel-dispensing device and ignition device. Coal dust served fuel.
The bellows injected the air jet mixed with coal dust into the ignition chamber where the glowing wick brought a mixture. After that, a partially imposed mixture (coal dust burns relatively slowly) hit the combustion chamber where he completely burned and extension occurred.
Next, the pressure of gases pushed water from exhaust pipethat forced the boat to move, after that the cycle was repeated.
The engine worked in a pulse mode with a frequency of ~ 12 and / minute.
After some time, the brothers had improved the fuel adding a resin into it, and later replaced it with oil and constructed a simple injection system.
For the next ten years, the project has not received any development. Claude went to England in order to promote the idea of \u200b\u200bthe engine, but she cleared all the money and did not achieve anything, and Joseph took up his photo and became the author of the world's first photo "View from the window".
In France, in the House-Museum of Niepsum, a replica "Pyreolophore" is set.
A little later, de Riva watered his engine to a four-wheeled wagon, which, according to historians, became the first car from the engine.
About Alessandro Volta
Volta for the first time placed plate from zinc and copper in acid to obtain a continuous electric current by creating the world's first chemical current source ("Volt Poll").
In 1776, the Volta invented the gas pistol - "Volta Pistol", in which the gas exploded from the electrical spark.
In 1800 built a chemical battery, which made it possible to receive electricity with the help of chemical reactions.
The name of the Volta is called the unit of measurement of electrical voltage - volts.
A. - cylinder, B. - "spark plug, C. - piston, D. - "Air" ball with hydrogen, E. - ratchet, F. - valve dump of exhaust gases, G. - Handle to control the valve.
The hydrogen was stored in the "air" ball with a connected pipe with a cylinder. The supply of fuel and air, as well as the approach of the mixture and the release of exhaust gases was carried out manually, with the help of levers.
Principle of operation:
Through the reset valve of the exhaust gases into the combustion chamber was air.
The valve closed.
A tap of hydrogen feed from a ball opened.
Crane closed.
By pressing the button fed an electrical discharge on the "candle".
The mixture flashed and raised the piston up.
Opened valve discharge valve gases.
The piston fell under his own weight (he was heavy) and pulled the rope, which turned the wheels through the block.
After that, the cycle was repeated.
In 1813, de Riva built another car. It was a wagon of about six meters long, with two-dimensional diameter wheels and weighing almost tons.
The car was able to drive 26 meters with a cargo of stones. (about 700 pounds) and four men, at a speed of 3 km / h.
With each cycle, the car moved to 4-6 meters.
Few of his contemporaries seriously belonged to this invention, and the French Academy of Sciences argued that the internal combustion engine would never compete with a steam engine.
In 1833., American inventor Lemuel Wellman Wright, registered a patent for a two-stroke gas engine of internal combustion with water-cooled.
(see below) In his book, Gas and Oil Engines wrote about Wright Engine the following:
"The engine drawing is quite functional, and the details are carefully worked out. The explosion of the mixture acts directly on the piston, which through the connecting rod rotates the crank shaft. By appearance The engine resembles a high-pressure steam machine, in which the gas and air are supplied with the pumps from individual tanks. The mixture in spherical containers was settled during the lifting of the piston in the NTC (the upper dead point) and pushed it down / up. At the end of the clock, the valve opened and discharged exhaust gases into the atmosphere. "
It is not known whether this engine has ever been built, but there is its drawing:
In 1838., English engineer William Barnett received a patent for three internal combustion engines.
The first engine is a two-way one-sided action. (fuel burned only on one side of the piston) with separate gas and air pumps. The insertion of the mixture occurred in a separate cylinder, and then the burning mixture flowed into the working cylinder. The intake and release was carried out through the mechanical valve.
The second engine repeated the first, but was double action, that is, the burning occurred alternately on both sides of the piston.
The third engine was also a double action, but had intake and exhaust windows in the cylinder walls open at the time reaching the extreme point of the extreme point (as in modern two-stakeholders). This allowed to automatically produce exhaust gases and insert a new charge of the mixture.
A distinctive feature of the Barnett engine was that the fresh mixture was compressed by the piston before ignition.
Drawing of one of the Barnett engines:
In 1853-57, Italian Inventors Economy Barzantti and Felice Mattecchi developed and patented a two-cylinder internal combustion engine. Power 5 l / s.
The patent was issued by the London Bureau as Italian legislation could not guarantee sufficient protection.
The construction of the prototype was charged with Bauer & Co. Of Milan » (Helvetica), and completed in early 1863. The success of the engine, which was much more efficient than the steam machine, was so great that the company began to receive orders from all over the world.
Early, single-cylinder engine Barzantty Mattecchi:
The model of the two-cylinder engine Barzantty Mattecchi:
Matteuchchi and Barzantti concluded an agreement on the manufacture of an engine with one of the Belgian companies. Barzantti left for Belgium to observe the work personally and suddenly died of typhus. With the death of Barzantty, all the work on the engine was discontinued, and Matteuchchi returned to her former work as a hydraulic engineer.
In 1877, Matteuchchi argued that he from Barzantti was the main creators of the internal combustion engine, and the engine built by August, Otto very much looked at the engine Barzantty-Mattecchi.
Documents concerning Barzantti and Matteuchchi patents are stored in the Museo Galileo library archive in Florence.
The most important invention of Nicolaus Otto was the engine with four-stroke cycle - Otto cycle. This cycle to this day underlies the work of most gas and gasoline engines.
The four-stroke cycle was the largest technical achievement of OTTO, but soon it was found that several years before his invention, the same principle of engine operation was described by the French engineer Bo de Rocha (see above). The group of French industrialists challenged Otto's patent in court, the court found them arguing convincing. Otto's rights that aroused out of his patent were significantly reduced, including its monopoly right to a four-stroke cycle.
Despite the fact that competitors have established the release of four-stroke engines, spent by many years of experience, the Otto model was still the best, and the demand for it did not stop. By 1897, about 42 thousand such engines of different power were released. However, the fact that light gas was used as a fuel, the area of \u200b\u200btheir use was strongly narrowed.
The number of luminaire plants was insignificantly even in Europe, and in Russia there were only two in Russia - in Moscow and St. Petersburg.
In 1865., the French inventor Pierre Hugo received a patent for the car represented a vertical single-cylinder engine of a double action, in which two rubber pumps operated for supplying the mixture crankshaft.
Later, Hugo constructed a horizontal engine similar to the Lenoara engine.
Science Museum, London.
In 1870, Austro-Hungarian inventor Samuel Marcus Siegfried constructed an internal combustion engine working on liquid fuel and installed it on a four-wheel cart.
Today, this car is well known as the "The First Marcus Car".
In 1887, in collaboration with Bromovsky & Schulz, Markus built a second car - "Second Marcus Car".
In 1872., The American inventor patented a two-cylinder internal combustion engine of a constant pressure operating on kerosene.
Brighton called his engine "READY MOTOR".
The first cylinder performed the function of the compressor that was injected into the combustion chamber, which continuously arrived kerosene. In the combustion chamber, the mixture was mounted and through the spool mechanism came to the second - the working cylinder. An essential difference from other engines was that the fuel-air mixture was burning gradually and at constant pressure.
Interested in thermodynamic aspects of the engine, can read about the "Breiton cycle".
In 1878.Scottish Sir Engineer (in 1917 dedicated to knights) Developed first two-stroke engine With ignition of a compressed mixture. He patented him in England in 1881.
The engine worked in a curious way: air and fuel was supplied to the right cylinder, it was mixed there and this mixture was pushed into the left cylinder, where the combustion of the mixture from the candle took place. Expansion occurred, both pistons lowered, from the left cylinder (through the left nozzle) Exhaust gases were thrown out, and a new portion of air and fuel was absorbed into the right cylinder. Following the inertia, the pistons rose and the cycle was repeated.
In 1879., built quite reliable gasoline two-stroke Engine and received a patent on it.
However, the real genius of Benz manifested itself in the fact that in subsequent projects he managed to combine various devices (choke, ignition with sparks with battery, spark plug, carburetor, clutch, gearbox and radiator) On its products, which in turn has become a standard for all mechanical engineering.
In 1883, Benz founded Benz & Cie on production gas engines and in 1886 patented four-stroke The engine that it is used on its cars.
Thanks to the success of "Benz & Cie", Benz was able to design of slaughtered crews. By combining the experience of making engines and long-standing hobbies - construction of bicycles, by 1886 he built his first car and called him "Benz Patent Motorwagen".
The design is strongly reminded by a three-wheeling bike.
Single-cylinder four-dimensional internal combustion engine with a working volume of 954 cm3. Mounted on " Benz Patent Motorwagen.".
The engine was equipped with a large flywheel (used not only for uniform rotation, but also for launch), a 4.5 liter gas tank, an evaporative type carburetor and a spool valve through which the fuel was entered into the combustion chamber. The ignition was made by the spark plug in the Benz's own design, the voltage was supplied from the Rumkor's coil.
Cooling was a water, but not closed cycle, but evaporative. Steam went into the atmosphere, so that the car had to be charged not only with gasoline, but also water.
The engine developed the power of 0.9 hp With 400 rpm and accelerated the car to 16 km / h.
Karl Benz for the "Board" of his car.
A little later, in 1896, Carl Benz invented opposite Engine (or flat engine) In which the pistons reaches the top dead point at the same time, thereby balancing each other.
Museum "Mercedes-Benz" in Stuttgart.
In 1882., English Engineer James Atkinson came up with the Atkinson's cycle and the Atkinson engine.
Atkinson's engine is essentially an engine operating by four-stroke otto cyclebut with a changed crank-connecting mechanism. The difference was that in Atkinson's engine, all four tacts occurred in one turn of the crankshaft.
The use of the Atkinson cycle in the engine made it possible to reduce the consumption of fuel and reduce the noise level when working due to less pressure during the release. In addition, this engine did not require a gearbox to drive the gas distribution mechanism, since the opening of the valves led the crankshaft.
Despite a number of advantages (including bypassing OTTO patents) The engine has not been widespread due to the complexity of manufacturing and some other flaws.
The Atkinson cycle allows you to get the best environmental performance and efficiency, but requires high revolutions. On small turns, it gives a relatively small moment and can stumble.
Now the Atkinson's engine is applied on hybrid cars " Toyota Prius."And" Lexus HS 250H ".
In 1884., British engineer Edward Butler, on the London Bicycle Show "Stanley Cycle Show" demonstrated the drawings of a three-wheel car with internal combustion gasoline engineAnd in 1885 built it and showed it at the same exhibition, calling "Velocycle". Also, Butler was the first one who used the word petrol.
Patent for "Velocycle" was issued in 1887.
The "Velocycle" was installed single-cylinder, four-stroke gasoline DVS Equipped with ignition coil, carburetor, choke and liquid cooling. The engine developed the power of about 5 hp With a volume of 600 cm3, and accelerated the car to 16 km / h.
Over the years, Batler has improved the characteristics of his vehicle, but it was deprived of the possibility of testing it because of the "Law of the Red Flag" (published in 1865) According to which the vehicles should not exceed the speed of over 3 km / h. In addition, three people were in the car, one of which was supposed to go before the car with the Red Flag (Such is safety measures) .
In the magazine "English Mechanic" from 1890, Butler wrote - "The authorities prohibit the use of a car on the roads, as a result, I refuse to further development."
Due to the lack of public interest in the car, Butler disassembled it on scrap metal, and sold the patent rights of Harry J. Louuson (bicycle manufacturer) which continued the engine production for use on boats.
Butler himself moved to the creation of stationary and ship engines.
In 1891., Herbert Eykroyd Stewart in collaboration with the company "Richard Hornsby and Sons" built the engine "HORNSBY-AKROYD", in which the fuel (kerosene) under pressure was injected in additional camar (because of the form it was called "hot ball")mounted on the cylinder head and connected with a combustion chamber by a narrow passage. The fuel flammped from the hot walls of the extra chamber and rushed into the combustion chamber.
1. Additional camera (Hot Ball).
2. Cylinder.
3. Piston.
4. Carter.
To start the engine, a soldering lamp was used, which heated an additional chamber (after launch it was heated by exhaust gases). Because of this, the engine "HORNSBY-AKROYD", which was predecessor diesel engine Designed by Rudolph Diesel, often called "Semi-Diesel". However, a year later, Eykroyd improved his engine adding a "water shirt" (patent from 1892), which made it possible to increase the temperature in the combustion chamber due to increasing the degree of compression, and now there was no need for additional source Heating.
In 1893., Rudolph Diesel received patents on a heat engine and a modified "carno cycle" called "Method and apparatus for the conversion of high temperature to work".
In 1897, on the "Augsburg machine-building factory» (since 1904 MAN), with the financial participation of the company Friedrich Krupp and the Zulzer brothers, the first functioning Diesel Rudolph Diesel was created
Engine power was 20 horse power At 172 revolutions per minute, the efficiency of 26.2% with a weight of five tons.
It was much surpassed existing engines Otto with efficiency of 20% and ship vapor turbines with efficiency 12%, which caused the living industry in different countries.
The diesel engine was four-stroke. The inventor found that the efficiency of the internal combustion engine increases from increasing the degree of compression of the combustible mixture. But it is impossible to compress the combustible mixture strongly, because the pressure and temperature increases and it is self-proposal ahead of time. Therefore, the diesel decided to compress it is not a combustible mixture, but clean air and the end of the compression inject fuel into the cylinder under strong pressure.
Since the compressed air temperature reached 600-650 ° C, the fuel was self-proposal, and the gases, expanding, moved the piston. Thus, diesel managed to significantly increase the efficiency of the engine, get rid of the ignition system, and instead of the carburetor use fuel pump high pressure
In 1933, Elling prophetically wrote: "When I started working on a gas turbine in 1882, I was firmly confident that my invention would be in demand in the aircraft industry."
Unfortunately, Elling died in 1949, and without surviving the era of turbojet aviation.
The only photo that managed to find.
Perhaps someone will find anything about this person in the Norwegian Museum of Technology.
In 1903., Konstantin Eduardovich Tsiolkovsky, in the journal "Scientific Review" published an article "Investigation of world spaces with reactive devices", where he first proved that the device capable of making a space flight is a rocket. The article was also offered the first project of a long-range missile. The body was an oblong metal chamber equipped with liquid jet engine (which is also an internal combustion engine) . As a fuel and oxidant, he offered to use liquid hydrogen and oxygen respectively.
Probably on this rocket and space note and it is worth finish the historical part, since the 20th century came and the internal combustion engines began to be made everywhere.
Philosophical Afterword ...
K.E. Tsiolkovsky believed that in the foreseeable future, people will learn to live if not forever, then at least very long. In this regard, there will be little space (resources) on Earth and will need ships for resettlement to other planets. Unfortunately, something in this world went wrong, and with the help of the first missiles, people decided to simply destroy themselves like ...
Thanks to everyone who read.
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Any use of materials is allowed only with an active reference to the source.
Engines of external combustion
An important element The implementation of the energy saving program is to provide autonomous sources of electricity and heat of small residential entities and remote from centralized networks of consumers. To solve these tasks, innovative installations for generating electricity and heat based on external combustion engines are best suited. As a fuel, both traditional fuels can be used and associated petroleum gas, biogas obtained from wood chips, etc.
Over the past 10 years, increased prices for fossil fuels, increased attention to CO 2 emissions, as well as a growing desire to stop depending on fossil fuels and fully ensure itself with energy. This was the consequence of the development of a huge technology market capable of producing biomass energy.
External combustion engines were invented almost 200 years ago, in 1816. Together with the steam engine, a two-and four-stroke engine of internal combustion, external combustion engines are considered one of the main types of engines. They were designed to create engines that would be safer and more productive than the steam engine. At the very beginning of the 18th century, the lack of suitable materials led to numerous deaths due to the explosions of steam engines under pressure.
The significant market for external combustion engines was formed in the second half of the 18th century, in particular, due to smaller applications, where they could be safely operated without the need for skilled operators.
After the invention of the internal combustion engine at the end of the 18th century, the market for external combustion engines disappeared. The cost of producing an internal combustion engine in comparison with the cost of production of external combustion is lower. The main disadvantage of internal combustion engines is that for their work it is necessary to clean, fossil fuel, increasing CO2 emissions, fuel. However, until recently, the cost of fossil fuels was low, and CO2 emissions did not pay due attention.
Principle of External Combustion Engine
In contrast to the widely known process of internal combustion, in which the fuel is burned inside the engine, the external combustion engine is driven by an external heat source. Or, more precisely, it is powered by temperature differences created by external heating and cooling sources.
These external sources of heating and cooling can serve the exhaust gases of biomass and cooling water, respectively. The process leads to a rotation of the generator mounted on the engine, whereby energy is produced.
All internal combustion engines are powered by temperature differences. Gasoline, diesel engines and external combustion engines are based on the features that it is less effort to compress cold air than to compress hot air.
Gasoline and diesel engines suck cold air And this air is compressed before it is heated in the process of internal combustion, which occurs inside the cylinder. After heating the air above the piston, the piston moves down, whereby the air expands. Since the air is hot, the force acting on the rod of the piston is great. When the piston comes to bottom, the valves open and hot exhausts are replaced with new, fresh, cold air. When the piston moves up the cold air is compressed, and the force acting on the piston rod is less than when it moves down.
External combustion engine works in accordance with a little different principle. It has no valves, it is hermetically sealed, and the air is heated and cooled with the help of heat exchangers of a hot and cold circuit. The built-in pump driven by the movement of the piston provides air movement there and back between these two heat exchangers. During the cooling of the air in the heat exchange apparatus of the cold circuit, the piston compresses the air.
After compression, the air is then heated in the heat exchange apparatus of the hot contour, before the piston begins to move in the opposite direction and use the extension of hot air to actuate the engine.
The main principle of operation of the stirling engine is constantly alternating heating and cooling the working fluid in a closed cylinder. Usually, air acts as a working fluid, but hydrogen and helium are also used.
The cycle of the stirling engine consists of four phases and divided by two transition phases: heating, expansion, transition to cold source, cooling, compression and transition to heat source. Thus, when moving from a warm source to a cold source, there is an expansion and compression of the gas in the cylinder. It changes the pressure, due to which it is possible to get a job. Since the theoretical explanations of the wing of scientists of husbands, listen to their times tedious, so let's turn to a visual demonstration of the engine of Sterling.
How does the stirling engine
1. The main source of heat heats the gas at the bottom of the heat exchange cylinder. The pressure generated pushes the working piston up.
2. Machine pushes the casual piston down, thereby moving the heated air from the bottom to the cooling chamber.
3. Follows cool and compressing, the working piston lowers down.
4. The extensive piston rises up, thereby moving the cooled air into the lower part. And the cycle is repeated.
In the stirling machine, the working piston movement is shifted by 90 degrees relative to the movement of the piston-displacer. Depending on the sign of this shift, the machine can be an engine or heat pump. When shifting 0 degrees, the machine does not produce any work (except for friction losses) and does not produce it.
Another invention of stirling, which increased engine efficiency, became a regenerator, which is a chamber filled with wire, granules, corrugated foil to improve the heat transfer of the undergoing gas (in the figure, the regenerator is replaced by the ribs of the cooling radiator).
In 1843, James Stirling used this engine at the factory, where he worked as an engineer at that time. In 1938, Philips invested in a stirling engine with a capacity of more than two hundred horsepower and returns more than 30%.
The advantages of the engine Stirling:
1. omnivorous. You can use any fuel, the main thing is to create a temperature difference.
2. Low noise. Since the work is built on pressure drop working fluidand not on arson of the mixture, then noise compared to the internal combustion engine is significantly lower.
3. Easy design, hence the high margin of safety.
However, all these advantages in most cases are crossed by two large disadvantages:
1. Large dimensions. The working fluid needs to be cooled, and this leads to a significant increase in mass and sizes due to increased radiators.
2. Low efficiency. Heat is not supplied to the working fluid directly, but only through the walls of heat exchangers, respectively, the loss of the efficiency of the CPD.
With the development of the internal combustion engine, the stirling engine left ... No not in the past, but in the shadow. He is successfully operated as auxiliary power plants on submarines, in heat pumps on thermal power plants, as transducers of solar and geothermal energy into electric, with it related space projects for the creation of power plants operating on radioisotope fuel (radioactive decay occurs with temperature, who did not know). Who knows, perhaps Once the stirling engine is waiting for a big future!
The modern automotive industry reached such a level that without serious research it is impossible to achieve cardinal modernization in the design of internal combustion engines. This contributed to the fact that the designers began to pay attention to alternative development of power plants, such as Stirling Engine.
Some autocontracers focused their strength on the development and preparation for the release of electric and hybrid cars, other engineering centers spend funds to design engines on alternative fuel made from renewable sources. There are other different engine development, which in the future can become a new engine for various means of transport.
So possible source of mechanical energy for road transport The future of the external combustion engine, invented in the 19th century by scientist stirling invented in the 19th century.
Device and principle of operation
Stirling engine performs the transformation of thermal energy obtained from an external source into a mechanical movement due to a change in fluid temperature circulating in a closed volume.
At first after the invention, such an engine existed in the form of a machine acting on the principle of thermal expansion.
In the cylinder of the heat machine, the air in front of the extension was heated, cooled before compression. At the top of the cylinder 1 is a water shirt 3, the bottom of the cylinder is continuously heated by fire. The cylinder is a working piston 4, having sealing rings. Between the piston and the bottom of the cylinder is the displacer 2 moving in the cylinder with a significant gap.
The air located in the cylinder is pumped by the displacer 2 to the bottom of the piston or cylinder. The displacer moves under the action of a rod 5 passing through the piston seal. The rod in turn is driven by an eccentric device rotating with a delay of 90 degrees from the piston drive.
In the position "A", the piston is located at the bottom point, and the air is located between the piston and the displacer, is cooled with the walls of the cylinder.
In the next position "b", the displacer moves upwards, and the piston remains on the spot. The air, which is between them, is pushed to the bottom of the cylinder, coolant.
The position "B" is a worker. In it, the air heats up the bottom of the cylinder, expands and raises two pistons to the upper dead point. After performing the working stroke, the displacer goes down to the bottom of the cylinder, pushing the air under the piston, and cooling.
In the position "G", the cooled air is ready for compression, and the piston moves from the top point to the bottom. Since the work of compression of cooled air is less than the work of expansion of heated air, it is formed useful work. The flywheel at the same time serves as a kind of energy battery.
In the viewed version, the stirling engine has a small efficiency, since the heat of air after the working stroke should be removed through the walls of the cylinder into the coolant. Air for one move does not have time to reduce the temperature on the required value, so it was necessary to extend the cooling time. Because of this, the speed of the motor was small. Thermal efficiency was also insignificant. The heat of the exhaust air went into the cooling water and lost.
Different designs
There are various options for the device of power units operating on the principle of stirling.
The design of the execution "Alpha"
This engine includes two separate working pistons. Each piston is located in a separate cylinder. The cold cylinder is in the heat exchanger, and hot heats up.
Construction of the execution of "beta"
The cylinder with the piston is cooled on one side, and heats up from the opposite side. The cylinder moves the power piston and the displacer serving to reduce and increase the volume of working gas. The regenerator performs the reverse movement of the cooled gas into the heated space of the engine.
The design of the execution "Gamma"
The whole system consists of two cylinders. The first cylinder is cold. It moves the working piston, the second cylinder on one side is heated, and on the other - cold, and is designed to move the displacer. The regenerator for chilled gas pumping may be common to two cylinders, or can be included in the displacer device.
Benefits
- Like the set of external combustion engines, the stirling engine is capable of functioning on different fuel, since it is important for it the presence of a temperature difference. At the same time, it does not matter what fuel it is called.
- The engine has a simple device, and does not need auxiliary systems and attachments (gearbox, timing belt, starter, etc.).
- Design features provide long operation: More than 100 thousand hours of constant work.
- The work of the stirling engine does not create a big noise, since the fuel detonation does not occur inside the engine, and there is no release of exhaust gases.
- The execution of "beta", equipped with a crank-connecting rod device in the form of a rhombus, is the most balanced mechanism, which does not create vibration during operation.
- In the motor cylinders do not arise the processes that have a harmful effect on the natural environment. When selecting the optimal heat source, the stirling motor can be an environmentally friendly device.
disadvantages
- With significant positive characteristics Fast serial production of stirling engines is unreal for some reason. The main question in the material intensity of the device. To cool the working fluid, a large radiator is needed, which significantly increases the dimensions and weight of the equipment.
- Today's level of technology allows the stirling engine to compete according to the properties with new gasoline engines Due to the use of complex types of working fluids (hydrogen or helium), which are under very large pressure. This significantly improves the risk of using such engines.
- The serious problem of operation is related to the problems of the temperature durability of steel alloys and their thermal conductivity. Heat is suitable for the workspace with the help of heat exchangers. This leads to significant heat loss. Also, the heat exchanger should be made from heat-resistant alloys, which should also be resistant to elevated pressure. The materials corresponding to these conditions are very complex in processing and have a high cost.
- The principles of the stirling engine transition to other operating modes are also significantly different from the usual principles. To do this, the creation of special control devices. For example, to change the power you need to change the angle of the phases between the power piston and the displacer, the pressure in the cylinders, or change the capacity of the working volume.
Stirling engine and its use
If you need to create a heat converter of compact sizes, you can easily use the stirling motor. At the same time, the effectiveness of other similar engines is significantly lower.
- Universal sources electricity. Stirling motors can convert heat into electricity. There are solar electrical installation projects with such engines. They are used as autonomous power plants for tourists. Some manufacturers make generators acting from gas burner. There are also projects of generators who work from radioisotope heat sources.
- Pumps . If a pump is installed in the outlet of the heating system, then the efficiency of heating increases significantly. In cooling systems, the pumps are also installed. The electric pump can fail, besides, it consumes electrical energy. The pump acting on the principle of Stirling solves this issue. The stirling engine for pumping liquids will be simpler by the usual scheme, since instead of the piston, the pumped liquid itself can be used, which also serves for cooling.
- Refrigeration equipment . The design of all refrigerators uses the principle of thermal pumps. Some refrigerator manufacturers plan to install the stirling engine to their products, which will be very economical. The working flu will be air.
Ultra low temperatures. For gases, such motors are very effective. Their use is more profitable than turbine devices. Also, the stirling engine is used in devices for cooling the sensors of accurate devices.
- . Electrical energy can be obtained by converting the energy of the Sun. For this purpose, stirling engines can be used, which are installed in the focus of the mirror so that the place of heating is continuously illuminated by the rays of the sun. The reflector is controlled as the sun moves, the energy of which is concentrated on a small area. In this case, the radiation reflection with mirrors is about 92%. The engine's working fluid is most often helium or hydrogen.
- Batteries heat. Using the stirling device, you can reserve thermal energy using heat accumulators based on salts. Such devices have an energy supply, superior chemical, and have a smaller cost. Using the power to adjust the power, the increase and decrease in the phase angle between the two pistons can be accumulated mechanical energy, carrying out the engine braking. In this case, the engine serves as a thermal pump.
- Automotive. Despite the difficulties, there are valid models of stirling motor used for cars. Interest in such an engine suitable for the car, there was still in the last century. Developments in this direction were conducted by British and German auto-concerns. In Sweden, a stirling engine was also developed, in which unified serial units and nodes were used. The result was a 4-cylinder engine, the parameters of which are comparable to the characteristics of a small diesel engine. This engine was successfully tested as power aggregate For a multi-torr.
Today, studies of styling installations for underwater, space and other installations, as well as the design of the main engines are carried out in many foreign countries. Such a high interest in stirling motors has become the result of the public interest in the fight against the pollution of the atmosphere, the noise and preservation of natural energy sources.
