Performance Comparison of Absorption Heat Pump and Refrigeration in Low Temperature Waste Heat Recovery

Absorption heat pump and absorption refrigeration cycle are widely used in industries as two of the most important low-temperature waste heat recovery technologies. In order to compare their energy and economic performances, this paper establishes the models of one effect LiBr –H2O absorption heat pump and one effect LiBr -H2O absorption refrigeration cycle in the process simulation software Aspen PLUS. The two systems are simulated for waste heat source under temperature from 95 (C to 125 (C saturated water to output 130 (C saturated steam (absorption heat pump), or 7 and 10 °C cold water (absorption refrigeration). The energy and economic performances of the two technologies are compared and analyzed through three parameters, coefficient of performance, exergy efficiency, and operation cost per unit exergy output. The results show that the performance of heat pump is better than that of refrigeration cycle under each of these evaluation indexes. The work in this paper aims to provide some theoretical support and technology selection suggestion for low temperature waste heat recovery.