A study on temperature spatial distribution of a greenhouse under solar load with considering crop transpiration and optical effects
A study on temperature spatial distribution of a greenhouse under solar load with considering crop transpiration and optical effects
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DOI：
10.1016/j.enconman.2022.115277
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发表时间：
2022-02
影响因子：
10.4
通讯作者：
Ke Xu;X. Guo;Junming He;B. Yu;Jinglu Tan;Ya Guo
中科院分区：
文献类型：
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作者：
Ke Xu;X. Guo;Junming He;B. Yu;Jinglu Tan;Ya Guo
温室空间温度分布对精准农业管理至关重要，尤其是垂直栽培模式。作物蒸腾和光学效应对温室空间温度分布的影响在文献中经常被忽略。基于能量守恒定律，考虑日光动态负荷下温室内空气（光吸收）、作物（光吸收、反射、透射和蒸腾）和土壤（光吸收和热辐射）的影响，建立了温室空间温度分布的计算流体动力学模型。一组现场试验用于验证开发的计算流体动力学模型。在考虑作物效应和不考虑作物效应的情况下，模拟了不同情景下温室的空间温度分布。结果表明：考虑作物效应的温室温度标准差比不考虑作物效应的温室温度标准差高约31.68%；这表明温室温度分布受作物蒸腾和光学效应的显著影响。结果还表明，温室顶部以下的空气区温度最高，且随太阳辐射动态方向变化，白天温度变化幅度约为63.65%。在考虑作物影响和不考虑作物影响的情况下，在相同高度的温室之间的温差为2°C-3°C。该研究对了解作物影响下温室温度的非均匀空间分布格局具有重要意义，并为温室温度传感器的部署、监测和控制提供信息。
Spatial temperature distribution of a greenhouse is critical to precision agriculture management, especially for the vertical cultivation mode. Crop transpiration and optical effects influence spatial temperature distribution of a greenhouse, which, however, were often omitted in literature. In this work, a Computational Fluid Dynamics model on studying spatial temperature distribution of a greenhouse was developed with considering the effects of air (light absorption), crop (light absorption, reflection, transmission, and transpiration), and soil (light absorption and heat radiation) in the greenhouse under dynamic solar load based on the law of energy conservation. A set of field tests was used to validate the developed Computational Fluid Dynamics model. Spatial temperature distributions of the greenhouse under different scenarios were simulated with and without considering crop effects. The results show that the temperature standard deviation of the greenhouse with considering the crop effects was about 31.68% higher than that without considering the crop effects. This implies that greenhouse temperature distribution is significantly influenced by crop transpiration and optical effects. The results also show that the highest temperature appears in the air region below the top of greenhouse and changes with the dynamic solar radiation direction, and the temperature may vary by about 63.65% during the day. There is a temperature difference of 2 °C-3 °C at the same height level between the greenhouse with and without considering the crop effects. This work is important for understanding the non-uniform temperature spatial distribution pattern of a greenhouse as affected by crops, and provides information for sensor deployment, monitoring, and control of greenhouse temperature.