Numerical Calculation And Experiment Investigation On The Characteristics Of Phase Change Wall In Summer Conditions

Phase change materials applied to building maintenance structure is a hotspot. The use of PCM can improve thermal properties and indoor thermal comfort of building maintenance structure to some degree. If phase change materials are applied in the wall, it melts and absorbs heat during the day and release heat at night to keep the room temperature in a comfortable range with the help of cold air. Based on the theoretical analysis, the method which theory analysis and numerical simulation are combined with experiment is used in research on the application, material parameter, operation condition and the really applied results on summer in the typical cities in different climate zones, in order to provide the theoretical proofs of selection and preparation of PCMs.With the deference of the inside and outside building temperature on summer and winter, it can draw the conclusion that PCMs with the single melting point can't meet the need of the annual thermal comfort. According to the characteristics of big temperature fluctuation in buildings on summer, the strategy of cooling in one day and accumulation in the next days can insure the actual summer operation of PCMs.The article established phase change room mathematics physics model and simulates the effectiveness of the parameters such as the melting point, the latent heat, temperature range during a standard day, the coefficient of heat conductivity and add position. The article summarizes the underlying principles and rule of the phase change heat transfer.Then the article simulates the effectiveness using CTYW,and make parametric optimization about melting temperature, the latent heat, the melting point range, heat conductivity and add position.At last, the article compares the effect of the phase change wall on summer in the typical cities in different climate zones, define the better melting point in typical cities, and make feasibility analysis on different zones. The articles propose optimization solution about operating mode, which is the optimization on mechanical supply air times. And it simulates the Air-conditioning energy consumption variation when the phase change wall is used.The results indicate that, the closer the melting point is to outdoor mean air temperature during summer, the better the effect is. In the area which the outdoor mean air temperature is below 26℃,the PCM can have received some effect, but can't completely replace the air conditioning.PCM combined with mechanical supply by night can improve the effect of phase change wall and enhance thermal comfort.PCM used in air conditioning buildings can reduce Indoor maximum thermal load effectively and Air-conditioning energy consumption, thus achieving energy conservation goals.