Numerical investigation of thermal management performances in a solar photovoltaic system by using the phase change material coupled with bifurcated fractal fins

Abstract

In this study, an enhanced passive solid-liquid phase change strategy based on the phase change material (PCM) and bifurcated fractal fins was developed for the thermal control of photovoltaic (PV) panels to optimize the performance of PV cells. Mechanisms of the fractal fin length ratio (r), model inclination angle (θ), and fractal fin bifurcation angle (φ) on thermal management performances in terms of the flow field structure, temperature contour, front plate temperature, liquid fraction, melting time, energy storage performance, and heat transfer coefficient were evaluated using a validated enthalpy-porous approach. The results demonstrated that the adoption of fractal fins could reduce the front plate temperature and improve its homogeneity for a given operating time, compared to a bare PCM heat management system without fins. In contrast to r and φ, the parameter θ had a more significant impact on the energy storage behavior of the PCM, which increased with the model inclination angle from 90° to 0° at 120 min. In particular, with the objective of lowering the front plate temperature as much as possible, the fractal case with r = 1.6, θ = 60°, and φ = 60° achieved the optimal performance with the maximum reduction of 19.2 K and the temperature uniformity of 2.8 K in front plate temperature compared to the PV system without fins.