Experimental investigation of the effects of hot-end and cold-end connection on the performance of a gamma type Stirling engine

Abstract

External combustion Stirling engines are considered as an alternative to the solution of increasing energy and environmental problems due to their ability to work with any heat source and to be an efficient energy conversion system. In this study, the effects of hot-end and cold-end connections of power and displacer cylinders on the performance of a gamma-type Stirling engine (GTSE) were investigated experimentally. The effects of the connection type between the power and displacer cylinders on the engine performance were compared at the same operating conditions without making any structural modifications to the engine. The performance tests were conducted using helium as the working gas at different charging pressures. The experimental results show that the maximum values of the engine torque and output power were obtained at a certain charging pressure for both hot-end and cold-end connected engines. Compared to the cold-end connection (CEC) engine, the maximum torque and output power increased in the hot-end connection (HEC) engine at the same temperature range. In the HEC engine, the maximum engine torque and power were achieved as 0.5665 Nm and 23.35 W, resulting in an increase of 68.4% and 84.7% compared to those of the CEC engine, respectively.