Performance Characteristics of a Heat-Assisted Stirling Heat Pump

This paper describes performance simulations and test results of a prototype to develop a multi-fuel gas engine driven Stirling heat pump. It is mainly driven by engine shaft power and is partially assisted by thermal power from the engine exhaust heat source. We have developed the D-3 machine, the fourth generation prototype of the heat-assisted Stirling heat pump. This machine uses helium gas as a working gas and is constructed as a combination of two Stirling sub-systems;one a power producer and one a heat pump. Utilizing both shaft power and thermal power, performance is controlled by phase shifting of the hot-side piston to adjust the absorbing of thermal power. This heat pump produced colling and heating water at high COP over 4 on an indicated basis. Developing this machine will provide a CFC-free thermal utilization system technology that satisfies both wide heat demands and various fuel systems.