การศึกษาสมรรถนะของระบบทำน้ำร้อนพลังงานแสงอาทิตย์แบบฮีตไปป์ / ธวรรธน์ มาลาหอม = a study of the performance of heat pipe solar collector for hot water system / Tawat Malahom
To study the performance of heat pipe solar collector for hot water system. The system consists of a heat pipe collector which its receive radiation area is 1.1625 sq.m., the insulated water storage which the volume is 200 L, a circulating pump and the temperature controller. The collector is installed at the angle of 35 to the horizontal plane and facing south direction. The hot water system is installed on the roof floor of building 5 in Chulalongkorn University. The operating parameters effecting the system are solar intensity, the initial storage water temperature, the final storage water temperature, the inlet water temperature of controller, the outlet water temperature of controller, ambient air temperature and Wind velocity. The data were collected at the interval of 2 minutes during 8:00 to 16:00 hour basis. The hot water stored energy and the efficiency of solar collector are calculated by the equation Q=MC [subscript P] (T[subscript f]-T[subscript i]) and eta=QX100/S From data analysis, the collector efficiency is depend on the solar intensity, the ambient air temperature, the mean of initial water temperature and final water temperature in the storage tank as governed by the empirical equation eta=-20.615(T[subscript i]-T[subscript a])/+0.4708 With the coefficient of determination, R [superscript 2] = 0.32 for the range of experiment. The system efficiency ranges from 22-28 °C the hot energy ranges from 3-6 MJ/day. And the maximum hot water temperature is 45.4 °C when the initial water temperature is 29.5 degress Celsius. The collector efficiency can be increased by inserting an aluminum foil reflective plate in the collector in order to increase the solar radiation absorption in the collector. From the experiment, it was revealed that the final storage water temperature in the storage tank increased 3-5 °C and the collector efficiency increased 11-13%.