基于日光温室相变材料的梯形墙体热特性分析

Analysis on Thermal Characteristics of Trapezoidal Wall Based on Phase Change Materials in Solar Greenhouse

将以石蜡为主的固-液复合相变材料喷涂到日光温室梯形北墙体内表面,对相变涂层温室梯形墙体和普通温室梯形墙体的热流量、北墙内的温度,以及室内外气温进行典型天气和月度变化的测试分析,以探究相变材料应用于日光温室梯形墙体后对室内热环境的影响。结果表明:晴天和阴天,相变涂层温室墙体的日间蓄热量和夜间放热量均显著高于普通温室墙体(P<0.05)。相变涂层温室墙体与普通温室墙体在同一典型时刻相同部位温度存在一定差异,这种差异随着墙体深度的增加而逐渐减弱,0.300mm墙体内差异最显著(P<0.05)。相变涂层温室墙体的累积蓄热量日平均值比普通温室墙体高8.1%,累积放热量日平均值比普通温室墙体高14.8%,相变涂层墙体表面和墙体内各层的月平均温度与普通温室墙体温度差异显著(P<0.05),相变涂层温室、普通温室和室外的月平均气温分别为9.93、8.63和.8.91℃。说明相变涂层墙体可有效增加墙体蓄放热量,提升温室气温尤其是夜间气温。

In order to explore the effect of phase change materials on the inner temperature of the solar greenhouse, the solid-liquid phase change composite material, in which paraffin wax was a main component, was sprayed onto the inner surface of north trapezoidal wall in the solar greenhouse. Then, the heat flux, temperature near the north trapezoidal wall, and the temperature indoor and outdoor both in the sprayed greenhouse and ordinary greenhouse were measured and analyzed by performing typical weather and monthly changed. The results showed that the heat storage in day-time and heat release in night-time of the north trapezoidal wall in the phase change coated greenhouse was significantly higher than that in the ordinary greenhouse (P<0.05). There was a certain difference in the temperature of the same layer and the same typical time of the phase change coating greenhouse and the ordinary greenhouse, which decreased gradually with the depth increasing of the north wall, and the difference between 0-300mm was the most significant (P<0.05). The daily average value of accumulated heat storage in the phase change coating greenhouse was 8.1% higher than that of the ordinary greenhouse, and the daily average value of accumulated heat release was 14.8% higher than that of the ordinary greenhouse.There was a significant difference between the monthly average temperature at the surface and the various inner layers in the north wall of the phase change coating and the ordinary greenhouse (P<0.05). The monthly average temperature in the phase change coating greenhouse, ordinary greenhouse and outdoor were 9.93℃, 8.63℃ and -8.91℃, respectively. It indicated that the phase change coating north wall effectively increased the heat storage and heat release and enhanced the greenhouse air temperature, especially the night temperature.