Performance Investigation on Electrochemical Compressor with Ammonia

The mechanical compressor on small cooling appliances has considerable energy consumption to the entire vapor compression system. To improve the efficiency of the compressor in the vapor compression system, an electrochemical compressor (EC) was suggested and its performance was investigated. The EC compresses refrigerant by charging an external voltage to the membrane electrolyte assembly (MEA). In this study, ammonia was used as a working fluid due to its high thermodynamic characteristics and electrochemically reactivity with the MEA. This paper mainly focuses on the thermodynamic compression limit at the open loop and the EC performance at the closed loop. The thermodynamic compression limit of the EC at open loop verifies the voltage and compression ratio relationship based on the theoretical Nernst equation. For the closed loop experimental study, the current density of the MEA was investigated with voltage at constant refrigerant charge. The pressure lift across the EC was measured as well. The measured flow rate was in the same order of magnitude of the theoretical values. In conclusion, the ammonia EC can be a new compressor option for the vapor compression system due to its potential energy saving, no moving parts and no lubrication oil.