Study On The Use Of Phase Change Materials In Light Building Envelope

In China, the amount of the annual building energy consumotion has occupied25%of the total social energy consumption, and the energy consumption of air conditioning, heating, hot water, lighting, ventilation accounted for more than80%of building energy consumption value. In addition, with the rapid development of China’s urbanization, the buildings are becoming increasingly high. So, the buildings develop towards lightweight, but the thermal storage performance of building envelope is poor, which results in the indoor temperature fluctuation, and high energy consumption. If we apply the phase change material to the lightweight building envelope, it can effectively reduce energy consumption, improve indoor comfort, but now its application to the building lacks theoretical analysis and quantitative measures.In this article, according to the characteristics of Tianjin climate, the author takes the SIP panels lightweight building envelope construction as the example, and by using the building energy simulation software(Designbuilder) analyzes, calculates the shading coefficient, ventilation rate, and compounds with the material of high heat capacity, analyzes the effect of the ratio of each window to wall on the SIP plate structure, accordingly put forward a method of reducing the energy value of the SIP plate structure.By using the Fluent simulation software, the article establishes three model, and does a simulation study according to the phase change materials used in the summer:(1)compound the phase change material on SIP, only natural ventilation cooling;(2)space air between the SIP panel structure and the phase change material for forced convection air cooling in the gap;(3)arrange the phase change material in a phase change energy storage module for forced ventilation. The author puts toward the suggestion that we can determine the volume of use of phase change material in lightweight building envelope, and determine the research methods of the temperature of the phase transition point of the phase-change material on the basis of the local climatic conditions.By using the Fluent simulation software, the article establishes a solar low-temperature radiant floor according to the phase change materials used in the summer, and does a simulation study combined with the phase change material. So we can find: the optimal phase transition point temperature and the supply and return water temperature of phase change materials used in the winter.