A Totally Heat-Driven Refrigeration System Using Low-Temperature Heat Sources for Low-Temperature Applications

Abstract

In the present study, a totally heat-driven refrigeration system is proposed and thermodynamically analyzed. This system uses a low-temperature heat source such as geothermal energy or solar energy to produce cooling at freezing temperatures. The proposed system comprises a Rankine cycle (RC) and a hybrid GAX (HGAX) refrigeration cycle, in which the RC provides the power requirement of the HGAX cycle. An ammonia–water mixture is used in both RC and HGAX cycles as the working fluid. A comparative study is conducted in which the proposed system is compared with two other systems using GAX cycle and/or a single stage cycle, as the refrigeration cycle. The study shows that the proposed system is preferred to produce cooling at temperatures from 2∘C to [Formula: see text]C. A detailed parametric analysis of the proposed system is carried out. The results of the analysis show that the system can produce cooling at [Formula: see text]C using a low-temperature heat source at 133.5∘C with the exergy efficiency of about 20% without any input power. By increasing the heat source temperature to 160∘C, an exergy efficiency of 25% can be achieved.

Energetic and Exergetic Investigations of Hybrid Configurations in an Absorption Refrigeration Chiller by Aspen Plus

“…The simulated results suggested that it was acceptable and effective to place the compressors between heat exchangers, as the coefficients of performance (COP) and the driving temperature of the hybrid systems improved compared with the original system. Seyfouri et al [6] proposed a compressor-assisted hybrid generator absorber heat exchange (GAX) refrigeration system powered by a built-in Rankine cycle to produce cooling below freezing temperatures (as low as −50 • C), for which the heat source temperature was 133.5 • C. Through a parametric study, the optimal operating conditions of the system were obtained. The performance was also enhanced, e.g., COP increased with the rise in the compressor discharge pressure.…”