Experimental evaluation of a 3 kW absorption chiller prototype

Thermally driven absorption chillers have the advantage of being powered by renewable or waste heat as well as using environmentally friendly refrigerants. However, micro scale capacities suitable for residential and office applications are still lacking. This study presents the experimental evaluation of a developed 3 kW capacity, single effect, hot water fired absorption chiller prototype. The chiller operates on the lithium bromide – water pair. To enhance wettability in the absorber, a double – tube configuration was employed to aid the falling film mode. Experimental test on the chiller showed the chilled water outlet temperatures from the evaporator ranged between 16.3 to 20.5oC. The chiller response time to cooling was about 15 minutes from the commencement of evaporation process at the evaporator. The chiller pressures stayed below 9 kPa throughout the experiment. Maximum cooling power of 2.01 kW was recorded, representing 67% of nominal cooling capacity. Maximum coefficient of performance (COP) of 0.47 was recorded, while an average COP of 0.43 was recorded.Keywords: absorption chiller, double – tube, experiment, cooling power, CO