Water Heating from Waste Heat of Air-Conditioner using a Closed-Loop Oscillating Heat Pipe with Check Valves as a Heat Exchanger

บทคัดย่อ

The aim of this research was to develop a water heater by using a closed-loop oscillating heat pipe with check valves (CLOHP/CV) as a heat exchanger. The CLOHP/CV heat exchanger was made from a copper capillary tube with an inner diameter of 2.03 mm. The lengths of evaporator, adiabatic and condenser were 20, 10 and 20 cm, respectively. The number of bends and check valves were 40 and 2, respectively. The inclination angle was 90o from horizontal axis. The CLOHP/CV with a fi lling ratio of 50% (by total volume of tube), using R134a, ethanol and distilled water as the working fl uids, were used for testing in this research. The water fl ow rate for heating was controlled at 0.5, 0.75 and 1 L/s. It was found that, the temperature of the water in the tank, the heat transfer rate and the effectiveness at a water fl ow rate of 0.5 L/s while the CLOHP/CV heat exchanger was fi lled with R134a as the working fl uid gave the highest temperature, the heat transfer rate and the effectiveness of all experimental results. This research can be used to develop a more effi cient CLOHP/CV heat exchanger for water pre-heating from waste heat from an air-conditioner for use in domestic and commercial structures to save electrical and energy costs.