Development of a beta-type moderate-temperature-differential stirling engine based on computational and experimental methods

Abstract

Stirling engine is a favorable technique in the application of waste heat recovery or cogeneration system. This paper aims at developing a beta-type Stirling engine which is operated at moderate heating temperature (773–973 K). Rhombic drive mechanism is utilized to make coaxial motion of displacer and piston. Based on the proposed dimensions, a theoretical model combining thermodynamic and dynamic analysis is built to predict the performance of the Stirling engine. Thermodynamic analysis deals with variations of properties in each chamber while dynamic analysis handles the resultant shaft torque produced by the Stirling engine. Furthermore, a prototype engine is manufactured, and experimental test is carried out to validate the simulated results in this research. Under heating temperature of 973 K, charged pressure of 8 bar, rotation speed of 1944 rpm, shaft power of 68 W is obtained from the prototype Stirling engine. Power density is calculated to be 1.889 W-c.c.−1 by theoretical prediction and 1.725 W-c.c.−1 by tested result. The impact of the geometrical dimensions is investigated to survey the optimal piston diameter which is related to compression ratio and swept volume.