反射隔热涂料在长沙地区的适用性研究

Application of Reflective Heat-insulating Coatings in Changsha

近年来,外墙反射隔热涂料得到了越来越广泛的应用。为了探究其在长沙地区的适用性及节能效果,采取实测和模拟的方法,通过对涂刷反射涂料、保温砂浆的测试房以及普通房的温度对比,验证了反射涂料在夏季起隔热作用而对冬季保温不利;运用EnergyPlus程序对表面吸收系数不同的两栋建筑进行温度和能耗对比,发现夏季反射涂料隔热效果明显,尤其是东、西外墙及屋面;反射涂料可显著降低夏季空调能耗,冬季能耗小幅增加,全年总能耗下降7.8%。

In recent years, exterior wall reflective heat - insulating coatings had been more and more widely used. Due to the different characteristics of solar radiation distribution in different regions, the contribution of reflective coatings was different and cannot be generalized. Even in the hot summer and cold winter regions, the effect of reflective heat - insulating coatings might be different because of the different environmental conditions in various urban. In order to study the applicability of building reflective heat- insulating coatings in Changsha and to measure the contribution to building energy conservation, actual measurement and simulation methods were both adopted to measure the energy - saving effects＇. The research results＇ could provide reasonable suggestions for the application of building reflective heat- insulating coatings in Changsha. In the field measurement, three test houses with the same area and the same basic structure were selected. The exterior wall of the testing room - 1 was painted with reflective heat - insulating coatings, and the test room - 2 was paintedwith insulation mortar and the same color ordinary paint. At the same time, the test room -3 was selected as the ordinary house which only brushing the ordinary paint. The indoor air temperatures of the three test rooms were tested in the coldest winter and hottest summer monthsrespectively. The temperature variation curve was drawn by extracting the representativethree- day test results, and theaverage value, maximum and minimum of air temperature were compared and analyzed. In the simulation, a single - room simplified building model wasestablished by EnergyPlus, anauthoritative simulation software for building energy consumption. The reflection coatings and ordinary coatings were painted on the building models respectively. The temperature changes of the inner and outer surfaces of the envelopes outside all directions were simulated in the coldest and hottest periods. Then the indoor temperature of the room is set to be 18 ℃ in the winter and 26 ℃ in the summer. The air -conditioning mode was fully on, and the monthly energy consumption and annual energy consumption of the building were simulated and compared. Through the test and simulation, the following conclusions were drawn： （ 1 ） No matter whether it was measured or simulated results showed that the reflective heat - insulating coating had good thermal insulation in summer. （2） In the field measurement, the reflective heat - insulating coating could reduce the average indoor air temperature by 2. 35 ℃ in comparison with the ordinary house in the summer, and the heat insulation effect was obvious. In winter, the reflective heat - insulating coating was unfavorable to the indoor thermal environment. The average indoor air temperature was lower than the ordinary house by 0.05℃. （3） The simulations showed that the architectural reflective heat - insulating coating could effectively reduce the peak of the external surface temperature and reduce the temperature of the internal sulface, which played a significant role of heat insulation in summer. The heat - insulating effect of architectural reflective coatings from high to low was. the roof, the east wall, the west wall, the south wall and the north wall. （4） Architectural reflective heat - insulating coatings had a significant effect on reducing air conditioning energy consumption in summer, which helped reduce peak summer electricity use. However, it was found that heating energy consumption was increased in winter, and annual energy consumption could be reduced by 7. 8%. Through the comprehensive analysis, it could be seen that reflective coatings have a good applicability in Changsha and are worthy of promotion. For other regions, to determine the suitability of reflective heat - insulating coatings and to avoid blind applications will help improve energy saving efficiency.