A new solar powered adsorption refrigerator with high performance

An adsorptive solar refrigerator was built in September 2000 in Yverdon-les-Bains, Switzerland. The adsorption pair is silicagel + water. The machine does not contain any moving parts, does not consume any mechanical energy except for experimental purposes and is relatively easy to manufacture. Cylindrical tubes function as both the adsorber system and the solar collector (flat-plate, 2 m2 double glazed); the condenser is air-cooled (natural convection) and the evaporator contains 40 l of water that can freeze. This ice functions as a cold storage for the cabinet (320 l). The first tests (September 2000) showed a very promising performance, with a gross solar cooling COPSR of 0.19. After minor modifications, a second test series was carried out during summer 2001. This test series shows how the external parameters influence the machine with respect to the COPSR (irradiation and external temperature). The latter varies between 0.10 and 0.25 with a mean value of 0.16. These values are higher than those obtained by earlier solar powered refrigerators (0.10–0.12). This paper describes the principle of the cycle, the different components of the machine, and the test procedure. The test procedure includes a constant daily cooling requirement. The experimental results presented were taken over a period of two months. 2004 Elsevier Ltd. All rights reserved.