墙体材料对日光温室温度环境影响的CFD模拟

    Simulation of temperature variations for various wall materials in Chinese solar greenhouses using computational fluid dynamics

    • 摘要: 日光温室墙体材料影响温室的蓄热保温性能。该研究以室外气象因子为模拟输入条件,分别对复合墙、全砖墙及全苯板墙的12 m跨度日光温室的温度环境进行了模拟,复合墙、全砖墙内的温度分布变化与以往的测试结果一致。以2004年2月18日实测的气候条件为输入条件,模拟得到复合墙温室温度超过全砖墙温室温度最大值为0.8℃,复合墙温室夜间室温超过全苯板墙温室温度最大值为1℃。早晨揭帘前,复合墙中隔热层以内的砖墙及部分隔热层成为放热体,砖墙中靠近室内近1/3的墙体温度高于室内空气温度,而全苯板墙只有内表面附近略高于室内空气温度。白天复合墙、全砖墙及全苯板墙温度均低于室内空气温度,均为吸热体。采用日光温室温度环境动态模拟模型,可以预测不同温室墙体可能形成的室内温度状况,并且根据不同墙体内温度分布,可优选温室墙体结构。

       

      Abstract: Wall materials play an important role in heat conservation for Chinese solar greenhouses. External climatic conditions were used here as inputs in simulations of the temperature environments for layered wall, brick wall and polystyrene foam plate (PFP) wall greenhouses with a span of 12 meters. The predicted wall temperature profiles agreed well with existing experimental results. External climatic conditions measured on Feb. 18, 2004 were used as the input, with the predicted maximum air temperature for the layered wall greenhouse 0.8℃ higher than that for the brick wall greenhouse and that for the layered wall greenhouse 1.0℃ higher than that for the PFP wall greenhouse. The thermal sources in the three types of greenhouses in the morning before the felt insulation was rolled up off consisted of the inside layer of brick and part of the insulating layer for the layered wall. Temperature of one third of the inside wall for the brick wall was higher than air temperature inside the greenhouse. The wall temperatures inside the layered wall, the brick wall and the PFP wall were below the air temperature inside the greenhouses during the day with the thermal blanket unrolled. The model accurately predicts the air temperatures inside greenhouses with various kinds of walls, so it can be used to select wall structures based on the temperature profiles inside different walls.

       

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