Proposal and analysis of a novel heat-driven absorption-compression refrigeration system at low temperatures

Absorption refrigeration systems have been widely applied to utilize waste heat from industrial processes. In this work, a novel heat-driven absorption-compression refrigeration system is proposed to produce the cooling energy required to reach a temperature as low as -60 degrees C. The proposed system is composed of three subsystems: a power generation subsystem using ammonia-water mixture working fluid, an ammonia-water absorption refrigeration subsystem, and a CO2 compression refrigeration subsystem. The system utilizes the heat source using a cascade approach. A simulation study is conducted, and the results show that, when the evaporation temperature is -55 degrees C, the cooling capacity per unit mass of flue gas and the coefficient of performance of the proposed system can reach 62.70 kJ kg(-1) and 0.277, respectively. The effects of the power subsystem working fluid concentration, the turbine inlet pressure, the split fraction and the intermediate condensation temperature on the system's performance are analyzed to provide guidance to the system design. Performance comparison shows that the proposed system has an outstanding adaptability, and its practical applications are also considered. This work may provide a new approach to producing low-temperature cooling energy using a mid-temperature heat source. (C) 2015 Elsevier Ltd. All rights reserved.