Performance of hybrid refrigeration system using ammonia

This paper investigates the performance of a hybrid refrigeration system that combines sorption conventional vapour compression refrigeration machine driven by dual source (heat and/or electricity). The dual source makes the system highly flexible and energy efficient. The ammonia refrigerant (R717) is used in both adsorption and associated conventional refrigeration cycles. The model of thermal compressor corresponds to a multiple pair of compact adsorption generators operating out of phase with both heat and mass recovery for continuous cooling production and better efficiency. Each generator is based on a plate heat exchanger concept using the activated carbon ammonia pair. The model of conventional vapour compressor is a reciprocating compressor from Frigopol. The hybrid refrigeration performances are presented mainly for ice making and air conditioning applications (T-C = 40 degrees C, -5 degrees C < T-E < 20 degrees C). The exhaust temperature of the compressor (driving temperature for thermal compressor) varies from 90 degrees C to 250 degrees C. The results show a cooling production ranging from 4 kW to 12 kW with back-up mode (both cycles not operating simultaneously) and from 8 kW to 24 kW with complementary mode (both cycles operating simultaneously). The effective overall COP based on the total equivalent heat rate input varies from 0.24 to 0.76. (C) 2013 Elsevier Ltd. All rights reserved.