Passive control and stability of the indoor temperature of a closed cavity based on the process of integrating phase change materials

摘要

A one-dimensional numerical model characterizing the coupled heat transfer between a three-layer PCM wall and a closed cavity is elaborated. This model is applied to study the passive control and stability of the indoor air temperature of a closed cavity which can designate a living space. The wall exposed to external disturbances consists of a phase change material, encapsulated in a rectangular container, and framed by an insulating and a building material. Phase change heat transfer is modeled by the use of the apparent heat capacity method where the heat capacity is numerically evaluated by the Hsiao approach. This approach is adequate and well adapted to numerical solution without the need to specify the solidification-melting temperature range for phase change materials. The numerical analysis is performed using an implicit finite difference scheme. The model is validated by comparison with previous work. The numerical simulations are performed with three types of PCM, namely calcium chloride hexahydrate CaCl2(6H(2)O), polyethylene glycol 900, and RT25-30. The results showed that for stability and control of indoor air temperature, the choice of PCM is based on its melting temperature which is preferably chosen close to the temperature of thermal comfort and with a significant latent heat. This model can be extended to the multilayer wall, PCM-porous medium wall, and used to determine the optimal position and thickness of the PCM layer.