Experimental study on the dynamic thermal performance of V-Ti black ceramic solar collector under multiple factors

摘要

In this paper, the effects of various factors on the dynamic thermal performance of vanadium-titanium black ceramic solar collector were studied experimentally. To calculate the instantaneous thermal efficiency of the collector system more accurately, this paper considers the temperatures of water in the collector, the water storage tank and pipes and proposes a calculation method for the transient temperature of the collector system, which is different from the temperature of the collector inlet and outlet and the temperature of the storage tank proposed in the literature. The results show that the thermal efficiencies of the collector do not exceed 1 over a small-scale time range, and the results are more accurate. In addition, this paper analyses the effects of water temperature, wind speed, working fluid flow rate, azimuth and tilt angle on the dynamic thermal performance of the collector. The calculation results show that the collector efficiency decreases sharply with increasing water temperature. Wind speed has little effect on the thermal performance of the collector in the daytime, but has a greater effect at night. The overall thermal performance of the system increases gradually with increasing working fluid volumetric flow rate. When the azimuth is positive in the south, the thermal performance of the collector is the highest on sunny days. To obtain the maximum radiation, the collector has the best tilt angle and azimuth in winter and throughout the year.