삼각저항체가 설치된 태양열 공기-물 가열기의 운전조건에 따른 집열성능 실험평가 및 상관관계 분석

Abstract

About 40% of the energy load of domestic buildings is used for heating and cooling, and most of them use fossil fuels to replenish heat sources. Policy subsidies for the use of new and renewable energy facilities are being activated to lower the proportion of fossil fuels. Solar facilities among renewable energy systems are those that can contribute to reducing the heating load of buildings, and are generally divided into air-type solar collectors that heat the air of the heat collection system and liquid solar collectors that heat only hot water. On the other hand, a solar air-water heater is capable of heating air and water at the same time, and can be applied to both hot water and air heating facilities in the same surface area, thereby increasing heat collection efficiency. To improve heat transfer performance, we manufactured a solar air-water heater with a triangular obstacle installed in an air channel, compared and analyzed the heat collection performance in accordance with the change of the air volume and flow rate under actual weather conditions. The heat collection performance was evaluated under the actual weather conditions according to the change of flow and air flow conditions, and based on the experiment was conducted under 9 conditions corresponding to the operating conditions of 70 CMH, 160 CMH, and 250 CMH at flow rates 2.5 L/min, 4 L/min, and 6 L/min. As a result of the experiment, the obtained heat value was 221.62∼1,008.55 W on the air side and 44.25∼780.17 W on the liquid side, and the total heat gain was 447.88∼1,509.37 W. The thermal efficiency was 11.97∼64.11% on the air side, 3.29∼41.7% on the liquid side, and 36.33∼74.32% on the total thermal efficiency, and the efficiency of the air and liquid side obtained by useful thermal energy was dimensionless to consider the weather conditions such as solar radiation and ambient temperature. The minimum efficiency of the air side of the solar air-water heater was 9.67∼23.76%, the maximum thermal efficiency of the air side at 250 CMH using the blower under the operating conditions, and the maximum efficiency of the liquid side was 38.83∼46.5%, showing the highest thermal efficiency of 6 L/min using the pump under the operating conditions.