New Energy Resources and Energy Storage
LIANG Tao, ZHANG Long, SHI Yundong, DENG Xinxing, CHANG Rui, ZHANG Chengbin
In order to explore the influence of environmental factors on the performance of photovoltaic/thermal (PV/T) collector with binary tree-shaped cooling channels, based on the energy conversion process of PV/T collector, a theoretical model of system heat transfer was established, the temperature distribution law of PV module surface and cooling fluid was studied, while the influence of environmental factors on the system electrical efficiency was analyzed. Results show that, for every 100 W/m2 increase in irradiation intensity, the surface temperature of PV module is increased by about 1.95 K, the system electrical efficiency is decreased by about 0.13 percentage points, and there is a significant difference on the temperature distribution of cooling fluid. As the inclination angle increases from 15° to 60°, the irradiation intensity on the PV module surface shows an upward convex curve trend, rising from 829.26 W/m2 to 870.12 W/m2 at first and then decreasing to 824.13 W/m2, and reaching its maximum value at around 35°. Meanwhile, the average temperature of surface is consistent with the change in the irradiation intensity received by the surface. But the system efficiency shows a downward concave curve trend, reaching its minimum value at around 35°. For every 5 K increase in ambient temperature, the external radiation temperature is increased by about 7.2 K, the average temperature of PV module surface is increased by about 0.5 K, and the system electrical efficiency is decreased by about 0.04 percentage points. As the ambient wind speed increases from 0 m/s to 2 m/s, the variation of system electrical efficiency is only within 0.1 percentage points. However, the changes of ambient wind speed and temperature have no significant impact on the heat dissipation effect of PV module.