Experimental Study of Absorptive Solar Powered Refrigerator in IBADAN (Nigeria) - 1: Performance in Actual Site

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Author(s) O.B Akinbisoye | I.F Odesola
Pages 381-389
Volume 3
Issue 3
Date March, 2013
Keywords Refrigeration, Energy, Adsorption, Solar

Abstract

Industrial refrigeration is one of the most energy consuming sector in the world today. In a world where electrical energy cost is increasing exponentially, the need for a refrigeration system that utilises minimal amount of energy becomes paramount. The solution lies in adsorption refrigeration system which is powered by heat energy from the sun. It is in this light, that a model to carry out the analysis of Activated carbon/Methanol pair for an adsorption ice-maker has been developed. Which will also help to determine the efficieny of the system using this same pair.

The design calculations were carried out using mathematical analysis which was obtained by means of weight and energy balance in addition to the relations between temperature, pressure, concentration and enthalpy of the working fluids (refrigerant and the adsorbent) and the energy source (Solar energy). For the fabrication of the system, quality seamless copper tubing (of BS EN 1057) was used for the pipe network. For this pipe network, series of 40mm and 30mm pipes were placed concentrically while their ends were welded together to form the reactor section and 25.4mm tubes were considered for the condenser and evaporator section. Perplex sheet and fibre glass were used for the evaporator compartment, flat plate solar collector for collection of the required heat energy, while the condenser tube was designed to be water-cooled in a concrete compartment.

During operation of this prototype, the solar insolation rose steadily from 80W/m2 at 8:00a.m to 926W/m2 at about 2:00p.m. During this period, the temperature of the adsorber bed also rose to a peak value of 980C, which was one of the highest recorded. With this level of insolation, the adsorbent desorbed effectively while the temperature of the cooling water rose by 50C. The evaporator pipes’ temperature decreased gradually from about 350C at 7:00pm until it reached a minimum value of 150C at 2:00am. With this result, a C.O.P of 0.025 was recorded.

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