Parametric effects on the performance of a solar-powered solid absorption refrigerator

Abstract

Further tests were carried out on a solar powered solid absorption refrigerator reported in[1]. The solid absorbent was CaCl 2 treated with CaSO 4 to increase its resistance to compacting and disintegration, while maintaining a good absorbent granule porosity[2]. The refrigerant was NH 3. Tests were carried out over the annual climatic variations at Nsukka, Nigeria. In addition, the generation stage was started at nominal pressures of 900, 500, and 200 kPa to determine the effect of charging pressure on the COP. The experiments also provided longer-term performance tests of the absorption/generation capability of the absorbent. Cooling was obtained for all test months except for July and August. For the dry and the harmattan climates, the useful overall COP varied over 0.017 to 0.053 and 0.008 to 0.042, respectively. Maximum daily useful cooling and ice production were 833.3 kJ/m 2 and 1.65 kg/m 2, from the 1.41 m 2 collector. The available overall COP initially increased with charging pressure but became insensitive to it at higher pressures. The useful overall COP initially increased with increasing charging pressure, and later decreased as the pressure was further increased. A total of over 40 recorded tests have been performed with no observed reduction in the performance of the unit.