Solar Adsorption Chiller for Public Health Centres

Abstract

The project aims to develop a solar adsorption chiller capable of producing 2 kg of ice with cooling capacity of 27 W. The activated carbon - methanol adsorption pair was used among other pairs such as Zeolite-Water, Carbon-Amonia, Silica gel-Water. Due to low evaporation temperature of methanol, this pair is more suitable for ice making technology. Energy supply to refrigeration and air-conditioning system constitutes a signi cant role in the world. The International Institute of Refrigeration (IIR) has estimated that approximately 15% of all electricity produced worldwide is used for refrigeration and air-conditioning processes of various kinds. Since India has different climate conditions and possess high average annual daily solar radiation, especially in summer months when there is a high demand of cooling. The daily Solar radiation on the surface of the adsorbent bed is about 15-27 MJ/m2. The effective exposed area of a at plate type collector having clear plane glass sheet was calculated as 0.90 m2. For 2 Kg of methanol, activated carbon required was 7 Kg. Two types of condensers were tested, the rst one was a helical copper tube immersed in water tank and the other was a copper tube with n. The evaporator had su cient volume to collect the entire condensed methanol. In order to enhance the heat transfer effect in evaporator, the heat exchange surface is designed as a series of four trapezoidal cells. The experiments were done using natural solar radiation. During experiments the operating pressure was found to be an important parameter. In this study the required cooling was not observed due to loss in vacuum. The advantage of these systems are noiseless, no maintenance cost, no moving parts, non-polluting and uses solar thermal collector, which is cheaper than photovoltaic cells.