Energy, exergy, environment and economic analyses and optimization of two-stage absorption–compression combined refrigeration system

In the present paper, integration of a two-stage absorption refrigeration system with a compression refrigeration system is proposed for utilizing low-temperature heat and reducing electric energy consumption. The proposed system is analyzed and compared with vapor compression system from the viewpoint of energy, exergy, environment and economics. The proposed system reduces the electricity consumption by 89.3% and CO2 emission from 112.6 to 12.1 ton/year. The size and cost of the system are determined by designing the heat exchangers. The optimization is also performed with the objective of minimizing the annual cost of plant operation which includes fuel exergy cost, initial investment and maintenance cost and environmental damage cost due to CO2 emission. The annual cost of its operation is 21.6% less than equivalent vapor compression refrigeration system which is further reduced by 18.2% through system optimization.