Thermodynamic performance study on a novel absorption‐ compression cascade refrigeration activated by an internal combustion engine

Abstract

A novel cascade refrigeration system was presented and studied, which could supply low-temperature cooling capacity for fishing boats and refrigerated trucks at a low energy cost. The cycle was cascaded by a high-temperature stage of absorption-compression combined refrigeration cycle and a low-temperature stage of the CO2 subcritical compression refrigeration cycle. The presented cascade cycle could not only utilize adequately the waste heat of the engine but also utilize adequately the excellent performance of the CO2 subcritical cycle operating on a low-temperature working condition. The high-temperature stage cycle had three solution modes, which could bring about an effective waste heat utilization of the engine and effectively decrease power consumption. Based on the proposed cascade cycle, a fundamental thermodynamic model was constructed and solved under different operating modes. The obtained results indicated that the performance coefficient of the cascade refrigeration system could reach 3.26, which was significantly higher than 2.1 of the traditional two-stage compression cascade refrigeration system. Moreover, the exergetic efficiency of the cascade refrigeration system could reach about 0.52 under the conditions of evaporating at -35 degrees C and condensing at 40 degrees C. The research findings can provide an effective solution for the utilization of waste heat in refrigerated trucks and fishing boats. Novelty Statement The novelty of this work lied in that a novel absorption-compression cascade refrigeration cycle was proposed, which can supply low temperature cooling capacity for refrigerant trucks and fisher vessels by extremely utilizing the waste heat exhaust gases and jacket water from internal combustion engine of vehicles or ships.