Development and test of a Stirling engine driven by waste gases for the micro-CHP system

In recent years, micro-CHP systems are attracting world attention. As one kind of external heating engines, Stirling engines could be applied to the micro-CHP systems driven by solar, biogas, mid-high temperature waste gases and many other heat sources. The development of a Stirling engine driven by mid-high temperature waste gases is presented first. The thermodynamic design method, the key parameters of the designed Stirling engine and its combustion chamber adapted for waste gases are described in detail. Then the performance test of the Stirling engine is carried out. During the test, the temperature of the heater head is monitored by thermocouples, and the pressure of the working fluid helium in the Stirling engine is monitored by pressure sensors. The relationships among the output shaft power, torque and speed are studied, and the pressure losses of the working fluid in the heat exchanger system are also analyzed. The test results demonstrate that the output shaft power could reach 3476 W at 1248 RPM, which is in good agreement with the predicted value of 3901 W at 1500 RPM. The test results confirm the fact that Stirling engines driven by mid-high temperature waste gases are able to achieve a valuable output power for engineering application.

► A β-type Stirling engine whose output power could reach about 3.5 kW is developed by ourselves.
► Waste gases are used as the heat source to drive the Stirling engine.
► Test on the relationship among the power, torque, and speed are presented.
► The pressure changing process of the working fluid in the heat exchanger system during the test is recorded and analyzed.