A Study on Relationship Between the Energy Balancing and the Real Experiment in a Hybrid Solar Heating System
Abstract
Research of the hybrid solar collector that can heat air and liquid simultaneously has been conducted for enhancement of the usage of solar energy. Thermal efficiency of this solar collector was investigated ranging from various operating conditions. This efficiency of the collector, however, was hard to generalize because of many factors that effect on the efficiency more than the traditional solar collector. Thus, in this study, the efficiency of hybrid collector was expressed by the energy balance and the efficiency of the collector was also investigated according to operating and external conditions. As a result, efficiency of the air side was increased with the increment of the inlet liquid temperature when the other conditions were constant different with traditional solar air heater. In case of liquid heating performance, efficiency was decreased with increment of inlet liquid temperature and decrement of solar radiation same as the traditional solar collector for hot water. Total thermal efficiency expressed as the ratio of the useful energy gain of heating mediums(air and liquid) to the incident of solar radiation was decreased with increment of inlet heating temperature and decrement of solar radiation similar with the traditional solar collector. Those tendencies are similar with the results of previous study, thus it can be regarded that the efficiency expressed from the energy balance as in appropriate. Furthermore, from these results it is expected to generalize the evaluation method of the hybrid solar collector and contributing for practical use if additional experiment with more various conditions are conducted.
Keywords
Solar thermal system, Hybrid solar collector, Air-conditioning, Hot-water supply, Energy saving