A pore-scale numerical model is presented for simulating the melting of phase change material (PCM) in a PCM-metal foam composite energy storage system. Instead of considering volume averaged domain for simulating the melting process, the present model resolves the geometry of the metal foam. Thus it can capture the effects of geometrical parameters such as the pore size and pore distribution as well as the localized heat transfer at the metal foam PCM interface more accurately. The model also incorporates the effect of convection on the melting process. The developed model comprises of a geometry creation model for generating the foam structure considering metal foam as overlapping circular pores of different pore radius. Heat transfer, phase change and convection are solved using an enthalpy based finite volume model. The model is validated with experimental results given in literature. Subsequently, the effect of convection on melting and energy storage rate in PCM-metal foam composite systems is studied for different pore size and different porosity of metal foam. Results indicate that the effect of convection is higher for higher porosity and larger pore size.

提出了一种孔尺度数值模型，用于模拟相变材料（PCM）在金属泡沫复合材料储能系统中的熔化。本模型无需考虑体积平均域来模拟熔融过程，而是解析金属泡沫的几何形状。因此，它可以更准确地捕获几何参数的影响，例如孔径和孔分布以及金属泡沫PCM界面处的局部传热。该模型还包括对流对熔化过程的影响。所开发的模型包括用于将金属泡沫视为具有不同孔隙半径的重叠圆形孔隙的泡沫结构的几何创建模型。传热，相变和对流使用基于焓的有限体积模型求解。用文献中给出的实验结果验证了该模型。随后，研究了在不同孔径和不同孔隙率的金属泡沫材料中，对流对PCM-金属泡沫复合材料系统的熔化和储能速率的影响。结果表明，对于较高的孔隙率和较大的孔径，对流作用更高。