Simulation studies on R134a-DMAC based half effect absorption cold storage systems

This paper presents simulation studies conducted on a half effect vapour absorption cycle using R134a-DMAC as the refrigerant-absorbent pair with low temperature heat sources for cold storage applications. The intermediate pressure of the cycle has been optimized for maximum COP. The effects of the temperatures of the evaporator, condenser, absorber and generator on the COP of the cycle have also been studied. It is found that the effect of the temperature of the low absorber on the performance is more pronounced than that of the high absorber. The COP for the baseline system is found to vary from 0.35 for low evaporating and high condensing temperatures to 0.46 for high evaporating and low condensing temperatures. The use of a condensate pre-cooler has resulted in an improvement of 5-15% in COP. The performance of this working fluid pair is better than that of ammonia-water for low heat source temperatures in the half effect configuration.