Exergy Analysis of a Single-Effect Water-Lithium Bromide Absorption Chiller Powered by Waste Energy Source for Different Cooling Capacities

摘要

A thermodynamic analysis of a 1 kW and 10 kW single-effect water-lithium bromide absorption chiller have been studied. The analysis includes both first law and second law of thermodynamics. The coefficient of performance (COP), exergetic coefficient of performance (ECOP) and the exergy losses (?E) through each component of the system at different operating conditions and cooling capacities are obtained. A COP of about 0.72, 0.78 and 0.76 can be achieved for 1 kW cooling load at 1.5, 5 and 10°C evaporator temperatures respectively. For 10 kW cooling load, the minimum and maximum values of COP was found to be around 80 and 90°C respectively. While the minimum and maximum value ECOP was found to be around 100 and 90°C generator temperature respectively. About 40% of the system exergy losses were found to be in the generator. The minimum exergy losses in the absorber with 1 kW cooling load occurs at generator temperature of 80°C for 10°C evaporator temperature. The optimum evaporator temperature for maximum COP was found to be 5℃ for both 1 kW and 10 kW cooling capacities. While at 1.5℃ evaporator temperature the ECOP was found to be maximum.