塑料连栋温室覆盖层的能量平衡模型的理论研究

Theoretical Study on Energy Balance Model of Covering Layer of Multi-Span Plastic Greenhouse

运用传热学及热力学的基本知识,以能量平衡法为理论研究平台,建立了一个反映塑料连栋温室覆盖层自身热物理特性的能量平衡模型。根据覆盖材料的反射率、透过率等热物理特性,以及设施内外气温、天空辐射温度、植物与室内地面温度等工作环境条件,对覆盖层的传热进行分析。在MATLAB环境中模拟,并以实验验证了该模型。就晴天和阴天两种天气情况下的覆盖层温度模拟而言,两个回归方程的R2值分别为0.9883和0.9875,回归直线拟合度较高,平均绝对误差在±1.04℃之内,平均相对误差为4.36%。结果表明,该模型物理意义明确,便于数值模拟,且模拟结果与实验吻合性好。

An energy balance model was established with the basic knowledge of heat transfer and thermodynamics theory,and energy balance method was used as theoretical research platform. The heat transfer of the covering layer was analyzed according to reflectance and transmittance of cover material,working conditions such as temperatures of inside and outside of facility,sky radiation,plant,floor and so on. The model was simulated in MATLAB environment,and verified by actual experiments. Taking the temperature simulation of the covering layer in sunny and cloudy day as examples,R 2 values of the two regression equations were 0.8999 and 0.9875,respectively. The mean absolute error was ± 1.04℃ ,and the mean relative error was 4.36%. As a result,the model was clear and definite in physics,being easy to do digital simulation. Moreover,the results of simulation matched the date of the experiments.