新疆砌块复合墙体和砖墙日光温室的传热数值模拟分析

【目的】 研究建立新的二维传热模型来模拟和优化日光温室,为日光温室墙体的设计、建设和维护提供科学合理的方法和依据。【方法】 采用ansys软件进行温度场和流场模拟,使用UG软件对日光温室造型,将顶部保温被等结构适当简化,计算域分为内部与外部空气两部分。运用DO辐射模型和湍流模型模拟,采用CFX-Post计算处理,得到温度云图 。【结果】 日光温室墙体为内外扰均为周期性非线性条件的二维非稳态热传导,白天14:00时2种墙体温室内超过12.0℃,各墙面间温差较小,对流传热不明显。夜间03:00时,砌块复合墙体日光温室地面上部有高度2.2 m、温度11.2℃的高温区。与北墙体表面距离相同的情况下,砌块复合墙体日光温室的温度值高于砖墙温度值,距离墙体表面越远,两日光温室温差逐渐降低,但砌块复合墙体日光温室温度始终高于砖墙日光温室。且随着时间的推移,两日光温室温差逐渐增加,到夜间06:00时,砖墙温度低于室内,没有散热;砌块复合墙体温度仍高于室内,继续散热。后屋面、脊高处是热量散失较多的部位。【结论】 砌块复合墙体日光温室的热性能明显好于砖墙日光温室,与实际栽培试验结果相同。

Numerical Simulation Analysis of Heat Transfer in Solar Greenhouse of Mortar Block Composite Wall and Brick Wall in Xinjiang

【Objective】 Sunlight greenhouse wall heat transfer process is a complex diverse architectural heat physical process. In order to comprehensively analyze the caloric transfer mechanism of solar greenhouse wall, and discuss about the caloric transfer law of the wall, a new two-dimensional heat transfer model is established in this research to simulate and optimize the structure of solar greenhouse. 【Methods】 Simulation of temperature distribution and flow distribution with ansys analysis software, UG software is used to shape solar greenhouses, The structure of top insulation quilt and skeleton is simplified properly, the computational domain is divided into two parts that include internal air and external air. Then the DO radiation model and turbulence model are used to simulate,using CFX-Post calculation processing,the temperature cloud map is obtained. 【Results】 The solar greenhouse wall is a two-dimensional unsteady heat conduction with periodic nonlinear condition internal and external disturbances, the temperature inside the solar greenhouse of two kinds of walls is higher at fourteen o'clock during the day, above 12.0℃,the temperature difference between the walls is small,the convection heat transfer is not obvious. At three o'clock in the night,there is a high temperature area of height 2.2 m、temperature 11.2℃ in the upper part of the block composite wall solar greenhouse floor.With the same distance from the surface of the north wall, the temperature value of block composite wall solar greenhouse is higher than that of brick wall, the farther away from wall surface, the temperature difference between the two solar greenhouses decreases gradually, but the solar greenhouse temperature of block composite wall is always higher than that of brick wall. And over time, the temperature difference between the two solar greenhouses increases gradually, by six o'clock in the night, the temperature of brick wall is lower than that of indoor, there is no heat dissipation; the temperature of block composite wall is still higher than that of indoor,continue to dissipate heat.The simulation results show that the roof and ridge height are the parts with more heat loss. 【Conclusion】 This numerical simulation, comparing the temperature distribution and changing trend of two kinds of greenhouse walls, shows that the thermal performance of the block composite wall solar greenhouse is obviously better than that of the brick wall solar greenhouse, which is the same as the actual cultivation test results, this research provides scientific and reasonable method and basis for the design, construction and maintenance of solar greenhouse wall.