Optimal design on fin-metal foam hybrid structure for melting and solidification phase change storage: An experimental and numerical study

A fin-metal foam composite structure is employed in the phase change energy storage coupled Organic Rankine Cycle system to enhance thermal performance. The 3-D numerical model is validated through an experimental system to analyze the impact of metal foam parameters and fluctuating heat source parameters (amplitude and half-period) on the system's storage-release process during heat source fluctuation. According to the Taguchi method, metal foam porosity significantly influences the total storage-release time. An increase in porosity leads to a continuous increase in the total storage-release time, while an increase in PPI and a decrease in heat source amplitude initially increase and then decrease the total storage-release time. Under constant metal foam PPI (10) and porosity (0.97), Case T (half period = 60 and amplitude = 1.0) demonstrates a 2.04 % increase in average heat transfer rate and a 1.78 % reduction in total storage-release time compared to Case 0 (constant heat source). The average heat release rate sees a 4.23 % increase, while total heat storage and heat release rise by 0.96 % and 1.87 %. The research has specific technical significance for the photothermal application of phase change energy storage technology to the variability and unpredictability of solar energy.