Thermal analysis of a novel single-effect absorption refrigeration system using water/ionic liquid as working fluids

Abstract

Based on the demand of improving the cooling performance of traditional absorption refrigeration system, a novel single-effect refrigeration system with assisted compressors using water/ionic liquids as working fluids was comprehensively analyzed. In present work, four kind of ionic liquids:1-butyl-3-methylimidazolium dibutylphosphate [BMIM][DBP], 1-methyl-3-methylimidazolium dimethylphosphate[MMIM][DMP], 1-ethyl-3-methylimidazolium dimethylphosphate [EMIM] [DMP], and 1-ethyl-3-methylimidazolium acetate [EMIM][AC], which was studied as working fluid in absorption system at the first time, was modeled and simulated in both systems. Thermodynamic properties of new single-effect refrigeration system were numerically analyzed by non-random two-liquid models and the mass and energy conservation equations. The effects of compression ratio(pr) and temperature on the COP and exergetic efficiency (ECOP) were graphed and discussed. The simulating results showed the potential of ionic liquids to be used as substitute for traditional working fluids. Moreover, comparison results suggested the system with auxiliary compressors was better than the traditional system for its lower heat source temperature and higher cooling performance. It was better to increase the compression ratio of the compressor located between the absorber and the evaporator than to increase the compression ratio of the compressor located between the generator and the condenser.