ANALYSIS OF A SOLAR HEAT PIPE HEATING AND ABSORPTION COOLING SYSTEM

A new concept which combines a flat-plate heat-pipe solar collector for daytime solar water heating by evaporation of a refrigerant and night-time water chilling by absorption refrigeration has been analyzed. Since the heat pipe is a passive heat transfer device, the entire system requires no pumps or auxiliary power for its operation. This makes the system reliable and requires little maintenance.; A comprehensive survey of literature was completed to establish the existing state of knowledge on intermittent absorption refrigeration, flat-plate solar heat collectors and night sky radiation cooling. The literature survey showed that the idea of using a passive device such as a heat pipe with the absorption refrigeration principle for both heating and cooling is relatively new.; A mathematical model for the heat-pipe flat-plate collector and the absorption refrigeration process was developed. Since the solar collector, which collects heat during the daytime, also acts as a night-time heat radiator, the mathematical analysis was developed to model the solar collector's performance during the daytime and the heat radiator's at night, with slight modifications. The computerized intermittent absorption refrigeration system model was used to study the effect of collector dimensions, number of glass covers used, the type of absorber surface, the number of heat pipes, the heat pipe diameter, and the volume and concentration of working fluid on the system's performance. The system performance was described by cooling ratio, average daily collector efficiency, and the overall ratio.; A cost-effectiveness study was also carried out to find the optimum thickness of the collector plate. The optimum plate thickness was used in the parametric study of the system. This report also presents the results of transient analysis of the system. This study provides design data so that an experimental system may be built and tested.