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