Performance analysis and multi-objective optimization of cooling tower assisted vapor compression-absorption cascaded and hybrid refrigeration systems.

Present work compares and optimizes the performance of cooling tower assisted cascaded and hybrid configurations of vapor compression-absorption integrated refrigeration system. Both the systems are designed to estimate their performance, size, and cost for the cooling capacity of 100 kW. Further, optimization strategies based on the Coefficient of Performance (COP), operational cost, and investment cost are followed to make the systems competitive. Four optimization cases, i.e. the COP single-objective, the total operational cost single-objective, the total investment cost single-objective, and the multi-objective optimization are performed and compared for both the systems. Comparative study of cascaded refrigeration system (CRS) with hybrid refrigeration system (HRS) shows that the COP and second law efficiency of CRS is 82.1% and 25.0%, respectively more as compared to HRS; whereas, the CO₂ penalty cost of CRS is almost half of HRS. The efficient energy utilization and lower CO₂ emission yields 46.1% lower annual operational cost in HRS as compared to CRS. Further, the economic analysis predicts that the investment cost of CRS is 10% less than that of HRS for same cooling capacity. Therefore, based on combined energy, exergy, environmental, and economic (4E) analyses, it can be concluded that the performance of CRS is better as compared to HRS. [ABSTRACT FROM AUTHOR]