Experimental evaluation of factors affecting performance of concentrating photovoltaic/thermal system integrated with phase-change materials (PV/T-CPCM)

Abstract

The photovoltaic/thermal (PV/T) system is a promising option for countering energy shortages. To improve the performance of PV/T systems, compound parabolic concentrators (CPCs) and phase-change materials (PCMs) were jointly applied to construct a concentrating photovoltaic/thermal system integrated with phase-change materials (PV/T-CPCM). An open-air environment is used to analyze the effects of different parameters and the intermittent operation strategy on the system performance. The results indicate that the short-circuit current and open-circuit voltage are positively correlated with the solar irradiance, but the open-circuit voltage is negatively correlated with the temperature of the PV modules. When the solar irradiance is 500 W⋅m−2 and the temperature of the PV modules is 27.5 ºC, the short-circuit current and open-circuit voltage are 1.0 A and 44.5 V, respectively. Higher solar irradiance results in higher thermal power, whereas the thermal efficiency is under lower solar irradiance (136.2–167.1 W⋅m−2 is twice under higher solar irradiance (272.3–455.7 W⋅m−2). In addition, a higher mass flow rate corresponds to a better cooling effect and greater pump energy consumption. When the mass flow rate increases from 0.01 to 0.02 kg⋅s–1, the temperature difference between the inlet and outlet decreases by 1.8 ºC, and the primary energy-saving efficiency decreases by 0.53%. The intermittent operation of a water pump can reduce the energy consumption of the system, and the combination of liquid cooling with PCMs provides better thermal regulation and energy-saving effects under various conditions.

Keywords

• Compound parabolic concentrator
• Factor analysis
• Open-air experiment
• Phase-change materials
• Photovoltaic/thermal system