Multi-parameter heat transfer analysis of molten PCM in an inclined enclosure

Abstract

• The natural convective heat transfer characters of molten phase change material (mPCM) in an inclined enclosure with forced convection boundary condition on one side and constant heat flux on another side is numerical studied, which is rare in previous literatures. • Heat transfer characters of two side walls and the whole enclosure are investigated separately. • Effects of Reynolds number, Rayleigh number aspect ratio and tilt angles on natural convection inside the enclosure are analyzed, and their influence on heat transfer are compared by quantifying. • A series of dimensionless parameters are conducted to quantitatively evaluate the heat transfer performance of mPCM. The efficiency of the photovoltaic (PV) panel would drop significantly as the absorbed solar radiation converts into heat. To improve the performance of PV, a novel cooling system with phase change material (PCM) and air forced convection cooling is developed, the flow and heat transfer of molten PCM (mPCM) under flow boundary is focused and investigated through numerical method. Three Rayleigh numbers for heat flux boundary (10 4 , 10 5 , and 10 6 ), five Reynolds numbers for forced convection boundary (1 × 10 4 , 1.5 × 10 4 , 2 × 10 4 , 3 × 10 4 and 4 × 10 4 ), three aspect ratios (5, 8, and 10) and tilt angles (30°, 45°, and 60°) for design parameters are considered. A group of dimensionless numbers is performed to describe heat transfer characteristics. It is concluded that different boundary conditions would cause different flow and heat transfer characteristics in the enclosure. Especially for the forced convection boundary, increasing Reynolds number can improve the heat transfer efficiency and reduce the temperature at the same time. Further, the influence of each factor on heat transfer is quantified, as the Rayleigh number increases by two orders of magnitude, Reynolds number increases by 33.33%, aspect ratio enlarged by double variation and tile angle varied by 50%, the heat transfer efficiency changes by 36.53%, 10.76%, 28.45% and 20.34%, respectively.