Exergy Analysis and Advanced Exergy Analysis of a Novel Power/Refrigeration Cascade System for Recovering Low-Grade Waste Heat at 90–150 °C
Xiaobin Liu, Mengxiao Yu, Zhiqiang Liu, Sheng Yang
Abstract
To alleviate the energy crisis and reduce CO2 emissions, a waste heat-driven system coupled with power and refrigeration is proposed. The exergy analysis and advanced exergy analysis are used to study this system. The results show that the exergy destruction rates of the two subcycles are close to the same level. The endogenous exergy destruction rate caused by the self-irreversibility of components is dominant. According to the distribution of exergy destruction rate obtained by advanced exergy analysis, the improvement strategy of combining component self-improvement, other component improvement, and system optimization for the system is presented. The three components with the highest avoidable endogenous exergy destruction rate and improvement priority are the CO2 generator, the LiBr generator, and the turbine. This work will help to improve the exergy efficiency of the energy conversion process, and it is also of significance to the utilization of low-grade energy and the sustainable development of chemical engineering.