The principle and related introduction of Stirling engine The principle of Stirling engine is to use the energy conversion brought by temperature difference. Stirling engine expands with heat and contracts with cold, and then the heated place dissipates quickly in time.
The cycle consists of two isothermal processes and two constant volume regenerative processes, which belongs to a generalized Carnot cycle. The key to realize Stirling cycle is to realize heat recovery. The heat engine envisaged by Sterling consists of two cylinders-a piston and a regenerator.
The factors restricting the practical application of Stirling cycle are: it is difficult to realize isothermal heat absorption and isothermal heat release of high and low temperature heat sources, it is difficult to realize regenerative heating of regenerator, residual working gas in regenerator, resistance loss of regenerator and piston stroke control. There are many products of toy Stirling cycle engine and Stirling refrigerator, but the influence of the above constraints on practical Stirling engine is increasing rapidly, which leads to the rapid decline of its competitiveness.
Extended data
The promotion of Stirling engine has three directions:
(1) Small distributed cogeneration system: Stirling engine can be applied to cogeneration system according to its characteristics. Cogeneration system can be divided into small distributed cogeneration system and large cogeneration system based on thermal power plant. Among them, the small distributed cogeneration system has the characteristics of miniaturization of equipment and diversification of fuel.
Small distributed cogeneration system is mainly composed of power device, heating device and other auxiliary devices, in which the power device is the core component of the whole system. Natural gas first enters the burner for combustion, and the generated high-temperature flue gas is first used to heat the high-temperature thermal cavity (zone) of the engine, and then exchanges heat with the heat exchanger, so that hot water flows into the water storage tank as domestic hot water, and low-temperature waste gas is discharged from the exhaust pipe.
At the same time, the cold cavity (area) of the cold water-cooled engine is also heated to obtain hot water. The working medium circulates between the high-temperature hot cavity and the low-temperature cold cavity, pushing the piston to reciprocate and do external work, and driving the engine to generate electricity.
(2) Low-level waste heat recovery: Stirling machine is also particularly suitable for recovering low-level waste heat, such as factory waste heat, geothermal energy and solar energy. In order to achieve good energy-saving benefits.
(3) Mobile power source: Stirling engine is miniaturized and lightweight, and can be used as the power source of pushers, road rollers and even submarines after its control performance is improved.
Baidu Encyclopedia-Stirling Engine
Introduction of Stirling Engine Cummins engine is designed and produced by Cummins Company. The displacement of Cummins engine is 1.4~9 1 liter, and the power range covers 3 1~3500 horsepower. Widely used in road vehicles such as heavy trucks, medium-sized trucks, buses, recreational vehicles, light commercial vehicles, pickup trucks, and off-road equipment such as construction machinery, mining equipment, agricultural machinery, ships and railways. The following is the introduction of Stirling engine that I collected. Welcome to reading.
brief introduction
Cummins Inc. (NYSE:CMI), the pioneer of diesel engine vehicles, was founded in 19 19, and its headquarters is in Columbus, Indiana, USA. Cummins is the world's leading manufacturer of power equipment, designing, manufacturing and distributing engines and related technologies including fuel system, control system, intake air treatment system, filtration system, exhaust gas treatment system and electric power system, and providing corresponding after-sales service. Headquartered in Columbus, Indiana, USA, Cummins provides services to customers through its 550 distribution agencies and more than 5,000 dealer outlets in more than 65,438+060 countries and regions around the world.
The engine department of EBU produces and sells diesel and natural gas engines with various powers and corresponding spare parts, which are used in the fields of automobiles, industry and power generation equipment. The displacement of Cummins engine is 1.4~9 1 liter, and the power range covers 3 1~3500 horsepower. Widely used in road vehicles such as heavy trucks, medium-sized trucks, buses, recreational vehicles, light commercial vehicles, pickup trucks, and off-road equipment such as construction machinery, mining equipment, agricultural machinery, ships and railways. Cummins engine not only enjoys a high reputation in the industry for its first-class reliability, durability and fuel economy, but also has been in a leading position in the fierce competition to meet the increasingly stringent automobile emissions (US EPA 2007/20/KLOC-0, European No.4 and No.5), off-highway motor equipment emissions (above Tier3) and marine engine emissions (IMO standard).
superiority
First, with forward-looking design and development capabilities, Cummins can formulate corresponding solutions for different emission standards. Second, the mature supporting capacity, Cummins emission control technology can perfectly match the engine life cycle and the whole vehicle, so that customers can get the best economic benefits. Thirdly, advanced exhaust emission control technologies include cooling EGR, selective catalytic oxidation (SCR) and particulate matter filter (DPF). Fourthly, with the continuous expansion of Cummins post-processing market, the scale of bulk purchasing is formed, thus providing customers with cost-effective products. Cummins ISF series 2.8/3.8-liter engines on the road market [Motives Cummins ISB series 4.5-liter, 6.7-liter /ISL series 8.9-liter engines Cummins ISM series 1 1 liter engines start.
differentiate
The displacement of M series engine is 1 1L (670 cubic inches), and that of N series engine is 14L (855 cubic inches). M 1 1 power range 168-373kW, cylinder diameter x stroke:125x147mm.n14 power range 146-358 kW. The appearance of cylinder diameter x stroke:140x152mm.m11Engine has better technical maturity than M series engine, and M 1 Engine is more expensive.
trait
B series is more fuel-efficient: advanced design and precision manufacturing from Cummins in the United States make the fuel consumption far lower than similar products. Powerful power: The design of wastegate valve makes the low-speed performance more perfect and the power is better. Excellent reliability: the cylinder block and cylinder head are integrated to prevent water leakage and oil leakage, and the number of parts is less than 25% compared with other similar products. The failure rate greatly reduces the lower maintenance cost: fewer parts and lower use failures greatly reduce the comprehensive maintenance cost of the engine. Compared with other similar products, the maintenance time is saved by more than 50%. Excellent cold start performance: equipped with intake electric preheating setting and 6.6KW high-power starter, the cold start performance of the engine is comprehensively improved.
It has passed the extremely low temperature verification of Mohe, an Arctic village in China, at MINUS 36 degrees, which meets the Euro II emission standards. C series is more fuel-efficient: advanced design and precision manufacturing from Cummins in the United States, combined with the economic improvement of China, make the fuel consumption 20% lower than that of domestic similar products. Strong power: the low-speed power is fully upgraded, and the starting performance is better. Faster acceleration and better climbing performance. Excellent reliability: the design of key components has enough margin. The strength is more than 30% of other similar products. The engine life is longer. Lower maintenance cost: fewer parts and lower use failures greatly reduce the comprehensive maintenance cost of the engine. Compared with other similar products, the maintenance time is saved by more than 50%. Excellent cold start performance: equipped with intake electric preheating setting and 7.8KW high-power starter, the cold start performance of the engine is comprehensively improved. It has passed the extremely low temperature verification of -36 degrees in Mohe, an Arctic village in China, and meets the Euro II emission standard.
The simple principle of Stirling engine The principle of Stirling engine is that the expansion piston starts from the far dead center and the compression piston starts from the near dead center, reaching the near dead center and the far dead center respectively. During this period, all the working gas enters the compression cylinder through the heat accumulator, and at the same time, the previously absorbed heat energy is isothermally dissipated at various points along the way in the heat accumulator to realize primary cooling and generate kinetic energy.
The practical application factors of Coriolis cycle include: it is difficult to realize isothermal heat absorption and isothermal heat release of high and low temperature heat sources, it is difficult to realize regenerative heating of regenerator, residual working gas in regenerator, resistance loss of regenerator and piston stroke control.
There are many products of toy Stirling cycle engine and Stirling refrigerator, but the influence of the above constraints on practical Stirling engine is increasing rapidly, which leads to the rapid decline of its competitiveness.
Extended data
Compared with internal combustion engines, heat engines have the following advantages:
1, suitable for all kinds of energy. Whether it is liquid, gas or solid fuel, almost any high-temperature heat source can be used when it is indirectly heated by a heat carrier system (such as a heat pipe).
Such as biomass energy (firewood, etc.). ), and the engine itself (except the heater) does not need to be changed, and the hot engine does not need to be supercharged by the compressor, so the general fan can meet the requirements and allow the fuel to have a high impurity content; Solar energy, which is one of the common uses of Stirling engine; Radioisotopes are usually used in submarines and deep space AIP systems.
2. Low noise. When the engine is running, the combustion of fuel is continuous, which avoids the process of knock work and intermittent combustion similar to that of internal combustion engine and realizes the advantage of low noise. This allows it to be used on submarines for better concealment. The single unit capacity of heat engine is small, which is 20 ~ 50kw, so the system capacity can be increased or decreased according to local conditions. The structure is simple, the number of parts is 40% less than that of the internal combustion engine, the price reduction space is large, and the maintenance cost is low.
3, not affected by air pressure. This is due to the isolation of the working substance from the atmosphere in the Stirling closed cycle. This makes it very suitable for high altitude areas.