EFFECT OF FOULING ON THE PERFORMANCE OF VAPOUR ABSORPTION REFRIGERATION SYSTEM

Abstract

The incessant increase in the cost and demand for energy has directed to more research and development to consume available energy resources proficiently by minimizing the waste energy. Absorption refrigeration systems gradually attract interest of the researchers. Absorption cooling bids the possibility of using heat to provide cooling. Furthermore due to fouling of heat exchangers its performance deteriorate results in lag in rate of heat transfer and hence consuming more energy in a refrigeration system. For the fact that an absorption refrigeration system uses more number of heat exchangers as compared to other such systems, the effect of fouling on its performance is investigated. The objective of this report is to present empirical relations for evaluating the characteristics and performance of a single stage Ammonia water (NH3-H2O) vapour absorption system under normal as well as fouled conditions. The essential heat and mass transfer equations and appropriate equations recounting the thermodynamic properties of the working fluid at all thermodynamic states are evaluated. An energy scrutiny of each component has been carried out and numerical results for the cycle. Finally the variations of several thermodynamic parameters are replicated and examined. The main effect of the fouling is to decrease the effectiveness of the heat exchanger. Thus, the overall conductance (UA) of the heat exchanger is decreased. In the present work COP of the vapour absorption refrigeration system is decreased under fouling by keeping the constant value of overall conductance. Due to the fouling in the heat exchangers performance of the vapour absorption refrigeration system is degraded by 8.81%.