Experimental study on electrochemical compression of ammonia and carbon dioxide for vapor compression refrigeration system

Abstract

After the establishing of Montreal Protocol Agreement, industries are seeking alternative refrigerants to replace HFCs with high GWP. Meanwhile, the efficiency of vapor compression refrigeration system still remains as a challenge. In this study, we propose an electrochemical compressor for the vapor compression refrigeration cycle running with ammonia or carbon dioxide as its working fluids. The single unit electrochemical compressor prototypes for both refrigerants were developed and their performances were demonstrated with a potential isothermal compression efficiency of 90%. The system level performance was modeled for both refrigerants with coefficient of performance of 5.1 for ammonia refrigeration and 3.9 for carbon dioxide refrigeration. The scaled-up compressor design with improved gas distribution channels and internal heat exchangers was also demonstrated for the system. Since the electrochemical compressor does not use any moving parts, it does not need to use lubrication oil as well as produce any noise or vibration. Moreover, it can potentially approach an isothermal compression for even higher energy efficiency and thus improve the system performance.