Research On The Application Of Phase Change Material SP-28 In The Building Energy Conservation

With the enrichment in people’s material life,the natural resources on earth are increasingly depleted now.As a country with large population,the personal average resources of Chinese is less than half of the world’s average level,as a result,the shortage of energy has caused serious pollution,rising prices and the sharp contradiction between supply and demand.Therefore,energy-saving is of great significance.Phase change materials become known and accepted and more and more valued recently as a kind of new energy-saving materials for the fact that its unique functions and features can make the energy transfer in time and space.Just take the type of solid-liquid phase change materials for example,its working principle is that when the temperature rises,phase change materials convert from solid to liquid during which the endothermic melting phenomenon occurs,which makes the rise of environmental temperature delay and slow down;when the environment temperature drops,phase change materials convert from liquid to solid during which the solidification heat emission phenomenon occurs,which makes the environment temperature decline at a slower pace.This study takes the inorganic composite material SP-28 as phase change energy storage material that added to the building wall and test its energy saving effect to find out the best proportions of phase change materials through the quality of different proportions of phase change walling.This paper analyzes the background and significance of phase change energy storage materials,introduces the research status,classification and characteristics,summarizes the selection principles and the theory of crystallization,and illustrates the phase change material performance test methods.The phase change temperature,latent heat and the specific heat capacity are tested by DSC with the result of 25.8 ℃,179.66 j/g and 2.2 kj/kg respectively,meanwhile,the durability of phase change materials proves good through 3,000 times of the hot and cold cycle test.In order to further prove the energy-saving features of phase change materials,this study uses expanded perlite as phase change material carrier and makes five different mixture ratio(0%,5%,10%,15%,20%)of the building wall with the cooperation of JianYuan Engineering Quality Test Co.,LTD.,in FuYang City Anhui Province.Due to the reason of leakage,the wall body of mixture ratio of 20% is eliminated.The other four walls are placed in the same environment with the hightemperature of summer for one side,and with thermocouple for temperature monitoring of the other side to compare heat transfer characteristics of phase change wall with ordinary wall by using ANSYS finite element heat transfer simulation.The experimental results show that phase change wall has the capacity of heat storage which can reduce environmental temperature fluctuations and make the change of the wall temperature delay;Phase change materials of the mixture ratio,the greater the heat accumulation effect,the better the result is.As to the leakage,soaking and economic effect,containing10% of phase change materials is the most suitable proportion to the building wall;Through the heat transfer simulation with ANSYS finite element software,the results show that the temperature change and phase change wall simulated experimental value maximum temperature difference is less than 1 ℃,the phase change materials begin to melt at about 26 ℃,the melting time lasts approximately 28,800 s,the solidification time 21600 s.The peak temperature of the phase change wall(10%)is 1.1 ℃lower than ordinary wall,and after phase transformation,the highest temperature of phase change wall is 1.39 ℃ higher than ordinary wall.The temperature variation trend of phase change wall and ordinary wall is roughly the same,but the former speed is slower than the latter,which shows that the phase change materials can make the change of temperature delay.As phase change material mass ratio increases,the temperature curve is flat,the content of the phase change materials can affect the entire wall of heat accumulation effect,as to the phase change material mass ratio,the greater the heat accumulation is,the better the effect is.By comparing the both results from the experiment and the simulation,it shows that phase change materials can effectively prevent the change of environmental temperature,reduce the use of air conditioning and heating,which can increase the environmental comfort,energy conservation and environmental protection.