Performance Analysis of a Novel Cascade Absorption Refrigeration for Low-Grade Waste Heat Recovery

Absorption refrigeration (AR) systems have been extensively used for utilizing waste heat from industrial plants. In this paper, a novel cascade absorption refrigeration (NCAR) is proposed to produce −40 °C cold energy via using low-grade waste heat. The developed system consists of an NH3/H2O AR cycle and LiBr/H2O AR cycle. A simulation study is conducted, on the basis of the revised model built in Aspen Plus. The impacts of feed concentration, generator temperature, low-pressure part pressure, high-pressure part pressure, and concentration range are investigated to offer guidance for NCAR designs. In addition, the developed NCAR aims to obtain a highest coefficiency of performance (COP). The maximum of COP is 0.19, and the exergy efficiency of NCAR reaches 9.71%. The economic performance of NCAR is compared with the industrial application. The results indicate that NCAR has an excellent adaptability. This present work proposes a novel method for producing low-temperature cold energy from low-grade waste heat.