Energy Conservation Research Of Composite PCM Wallboard Applied In The North Residential Building

In most areas of north China, because the winter sunshine rate is quite high and the intensity of solar radiation is big, the indoor air temperature is usually much high in the daytime. However, the indoor air temperature can also suddenly drop at night when the outdoor air temperature is lower, which resulting in the fluctuation of indoor air temperature is much high. If the utilization of solar energy and the PCM heat storage technology are well combined, Making use of the PCM's characteristic of large phase change latent heat, the building enclosure can store the redundant solar energy radiating in the room in the daytime, and the indoor air temperature can be controlled in the fitting range. When the room temperature drops at night, the building enclosure will release the solar energy stored in the daytime to the indoor air to stabilize the room temperature. Applying the passive PCM heat storage technology in the buildings, the renewable energy will be efficiently used, the building energy consumption will be significantly reduced, and the heat comfort of the room will also be distinctly improved.This research takes the residential buildings in Beijing with a high winter sunshine rate and a big intensity of solar energy as the study object. Basing on the building thermal physics, heat transfer and energy storage theory, applying the phase change heat storage material to the building enclosure, this paper researches the heat transfer theory of the buildings that apply the composite phase change heat storage material and their engineering applications, providing a design foundation and method for the future project which use the phase change technology. This study focuses on the following aspects for the theoretical and experimental research.Firstly, it researches the phase change heat transfer problem of single wallboard from the aspect of heat transfer theory and phase change heat storage theory. Basing on the thermal performance evaluation system of building enclosures, this paper analyses the heat transfer characteristic and the thermal performance feature of the ordinary wallboard, the heat insulation wallboard and the composite PCM wallboard under the condition of the inside and outside interference temperature wave and heat wave. And at the same time it discusses the influence of the PCM'phase change temperature, latent heat, thermal conductivity and the thickness on the inner surface temperature of the PCM wallboard. Then the paper establishes the dynamic mathematical and physics Model of the phase change room. Adopting the numerical simulation, it demonstrates the energy consumption characteristic of the phase change room in different climate areas in China. At last, combining the results of the shrinking size experimental rooms, the paper proves the feasibility and energy conservation characteristic when applying the PCM wallboard to the passive solar heat storage buildings. The research method and conclusion makes a valuable reference for the utilization of the PCM wallboard in the passive solar buildings.