Performance Evaluation of the Solar Air-water Heater Integrated with Triangle Obstacle According to Air and Water Mass Flow Rate

Abstract

Approximately 40% of the domestic building load is used for heating and cooling, and fossil fuels are commonly used to produce heat. To lower the proportion of fossil fuels, policy subsidies for the use of new and renewable energy facilities are being activated. Among them, solar thermal systems can contribute to reducing the heating load of buildings, including hot water supply and space heating. The production of thermal energy in this solar thermal system takes place in a collector, and the heat collection system is generally categorized into an air-type solar collector, which can heat only air, and a water-type solar collector, which can heat only water. In contrast, a solar air-water heater is a collector that can heat air and water simultaneously and can be applied to both hot water supply and space heating, occupying the same area. This system can also improve solar energy utilization by retrieving waste heat at the top of the absorber plate. In this system, the increase in thermal efficiency of the air side results in an improvement in the total efficiency of the collector as well as the air heating performance. Furthermore, the performance of the solar air-water heater is affected by air and water mass flow rates. Thus, in this study, a novel type of solar air-water heater with a triangle obstacle was fabricated, and the thermal performance of this system was experimentally evaluated using various air and water mass flow rates when air and water were heated simultaneously. We observed that a higher air and water mass flow rate can lead to higher thermal performance of the suggested system.