Experimental study of the effect of inclination angle on the thermal performance of heat pipe photovoltaic/thermal (PV/T) systems with wickless heat pipe and wire-meshed heat pipe

Two different heat pipe photovoltaic/thermal (PV/T) systems, namely, wickless heat pipe PV/T system and wire-meshed heat pipe PV/T system, were proposed. In this paper, the thermal performances of the two systems working on different inclination angles were experimentally investigated in an Enthalpy Difference Laboratory with a solar simulator. The thermal performance of the wire-meshed heat pipe is not as sensitive to the inclination angle as that of the wickless heat pipe. The wickless heat pipe PV/T system is recommended at latitudes higher than 20°, whereas wire-meshed heat pipe PV/T system is suggested at latitudes lower than 20°. Moreover, the thermal performances of both PV/T collectors at an inclination angle of 40° were further investigated, in which case both heat pipes worked at optimum conditions. The thermal efficiency of the wickless heat pipe PV/T system and wire-meshed heat pipe PV/T system at zero reduced temperature was 52.8% and 51.5%, respectively.