Experimental Study on Cooling of Solar Collectors Using Air-water Mixture

Large numbers of studies are reported on solar collectors using a single fluid to cool it, be it with water or with air only. The present paper reports a series of experiments that investigate into the performance of solar collectors that are cooled by an air-water mixture, a two-phase heat transfer fluid. This special way of cooling of solar collectors is designed in conjunction with a humidification-dehumidification cycle that produces hot water and saturate air at the same time to run an efficient solar distillation unit. Parameters analyzed in the study include the effects of the air-to-water ratio and the inner diameters of the absorber tubes of the solar collector. A mechanism to control air-water ratio was also developed in the process. The results indicate that the two-phase flows can efficiently cool solar collectors producing better cooling of absorber plates of solar collectors, under suitable operating conditions.