Computational fluid dynamic analysis of an adsorption-based cogeneration osmotic heat engines with stepwise porosity distribution

Abstract

Adsorption-based osmotic heat engines offer an alternative way for converting ultra-low temperature waste heat into electricity. Here, considering the heat and mass transfer characteristics in the adsorbent bed, a computational fluid dynamic model is developed to describe the adsorption-based osmotic heat engine for power and refrigeration cogeneration. Impacts of the porosity distribution, adsorption time, switching time, fin number and working solution-adsorbent pairs on system performance are comprehensively analyzed under different porosity distribution configurations. Results reveal that Configuration I leads to higher coefficient of performance (COP), exergy efficiency. However, Configuration II renders higher electrical efficiency. Compared with the uniform porosity configuration, COP and exergy efficiency are respectively elevated by 1.96% and 1.19% under the stepwise porosity configuration of 0.3–0.5. The electrical efficiency is increased by 15.5% with porosity configuration of 0.7–0.2. LiCl and AQSOA-Z02 under the stepwise porosity configuration of 0.7–0.2 can lead to the highest exergy efficiency of 7.76%.