Effects of a phase change material slab applied on the evaporator of a household refrigerator
Résumé
To investigate the effects of latent heat storage on the refrigerator performance, a dynamic model of a household refrigerator including a phase change material is developed. It is based on conservation equations for mass and energy applied to the two-phase/single phase flow inside the heat exchangers and a front immobilization technique for the solidification/melting processes in the phase change material. The refrigerator model is experimentally validated; simulation such as the evaporating and condensing temperatures, or the energy consumption are compared with measurements. In general, the model permits to predict the system operation within an acceptable margin. The numerical results show that the addition of the phase change material results in an enhancement of the heat transfer coefficient on the evaporator side, due to the conduction into the PCM. It results in a higher evaporating temperature which increases the energy efficiency of the system. The stored energy is delivered to the refrigerator cell during the off cycle and permits several hours of continuous operation without electrical supply.