Heat transfer performance of wet porous solar collectors under periodic conditions

摘要

Fourier's law was often used to study the heat transfer of collector plates. However, some scholars have found that under time-varying periodic boundary conditions, using Fourier's law for research will produce certain deviations. In the current work, periodic boundary conditions are used, so the effect of non-Fourier efficiency on the heat transfer of the collector plate needs to be considered. Based on the Cattaneo-Vernotte equation, a heat transfer model of the solar collector plate with a limited heat transfer rate is constructed, and the problem is solved by the lattice Boltzmann method. On this basis, the influence of radiation, porous media, humidity, and relaxation time on solar collectors is considered. And the average efficiency, tip temperature, and exergy loss of the collectors are quantitatively analyzed. The results show that when the non-Fourier effect is considered, the tip temperature of the collector plate decreases, the average efficiency and the exergy loss increase. Moreover, with the increase of relaxation time, the tip temperature is lower, the efficiency and the exergy loss are greater. As the humidity and radiation increase, the tip temperature decreases, and the exergy loss and average efficiency increase. When other factors remain unchanged, the average efficiency, tip temperature, and exergy loss increased with an increase in porosity.