Performance enhancement of a vapor compression system by condensate

摘要

Air-conditioning systems consume large amount of energy and generate considerable amount of condensate when operated in hot and humid climates. This study considers utilizing the generated condensate to pre-cool the air entering evaporators to improve systems performance. Experimental and analytical investigations are carried out by using an air-conditioning system of 4.75kW (16207 BTU/h) cooling capacity incorporated with an air pre-cooler and a condensate tank that acts as a thermal storage. During the pre-cooling-on period, the air inlet temperature of the evaporator is decreased by 5.7 degrees C (10.3 degrees F) and the compressor power consumption is reduced by 5.1% because of the decrease in discharge pressure. The coefficient of performance increases by 30.7% and second-law efficiency by 24.2%. The air pre-cooling is practical for 4-5hours daily during the daytime if a 450-1000kg of condensate cold thermal storage is employed. The deviation is 6.7% between the analytical and experimental results.