A novel multi-function “Y-shape” heat pipe photovoltaic/thermal (PV/T) system: Experimental study on the performance of hot water supply and space heating

Photovoltaic/thermal technology has the advantage of supplying power and thermal energy at the same time, and it has become a research hotspot as a solar energy system. However, most of existing PV/T systems can only provide single thermal energy, and still have application limitation in some condition. To expand the application field and functions, a novel “Y-shape” heat pipe PV/T system with two different condensers is proposed in this paper which could achieve the functions of generating hot water with liquid cooled condenser outdoor and space heating with air-cooled condenser indoor. A prototype of the system was constructed in cold region, and the performance of the system with different functions has been measured in winter. The experimental results indicated that the average electrical efficiency, thermal efficiency and overall efficiency of the system are 10.2%, 53.8% and 64.0% respectively in the hot water mode on a sunny day with the water temperature of a 150L tank increased from 9.8 °C to 37.5 °C; while 10.1%, 59.2% and 69.3% respectively in space heating mode with the air temperature of a 12 m2 room increased from 11.4 °C to 17.8 °C. Based on the experimental data of the system, the thermal efficiency intercept equations in two operating modes are fitted to describe their performance in different operating condition. This study provides the experimental data and design guide for the application and development of the heat pipe PV/T system.