jailcd2015011: Optimization Research on the Multilayer Wall Integrated with a PCM Layer

Abstract

Based on the enthalpy-porosity technique, a heat conduction model accompanied with solidification and melting processes is developed and numerically analyzed to research the energy conservation of building multilayer wall integrated with a PCM layer by the finite volume method. The influence of pertinent parameters such as the latent heat, the phase change temperature, the placement and the thickness of the PCM layer is studied on building energy conversation under the Chengdu typical climates of winter, summer and transition seasons. The results show that the PCM layer can decrease the building annual load, increase the time lag, decrease the decrement factor and improve occupants' comfort. When the phase change occurs under the suitable temperature conditions, high latent heat is conductive to decreasing the heat flow fluctuation, increasing the time lag and improving inner surface temperature stability. The stronger heat storage capacity is, the smaller indoor temperature fluctuation. It is more efficient that the PCM layer is located next to the internal surface and under this condition, the optimum solidus and liquidus temperatures are 14°C and 26°C under the Chengdu climates. And the annual inner surface heat flow can be reduced up to 13.36% for the PCM layer of 30mm and 9.64% for the PCM layer of 20mm compared with no the PCM layer.