摘要
为了研究温室内喷雾系统的降温效果,采用CFD方法对Venlo型玻璃温室在夏天自然通风状况下的喷雾降温过程进行了数值模拟。在充分考虑太阳辐射影响和室内水蒸气传输过程基础上,结合离散相模型,构建求解室内环境系统的3-D数学模型,并对边界条件的设置进行探讨。对Venlo型温室在喷雾降温措施下室内空气温、湿度的变化以及在整个温室空间的温度分布进行了数值模拟与预测,结果显示:温室内测点温、湿度的模拟值与实测值的平均相对误差分别为4.9%和5.7%,模拟结果与试验结果吻合良好,说明所建立的CFD模型有效,边界设置合理。喷雾前流场存在明显温度梯度分布,温度变化随着高度的增加而变缓。喷雾后,温室内温度迅速降低,喷头下方温度下降最为明显。随着时间的推移,温室内温度逐渐回升,温度回升速度与高度呈正相关关系。
To study the cooling effect of a spray system in greenhouse, computational fluid dynamics （CFD） method was used to simulate the cooling process in a naturally ventilated Venlo greenhouse in summer. The greenhouse environment was described as a 3-D model based on water vapor transmission and solar radiation with the porous model and the discrete phase model, and the boundary conditions were discussed. The change in air temperature and humidity and the distribution of temperature inside the greenhouse with fog-cooling measures were numerically simulated. The average error between the simulated and measured values for the temperature was 4.9%, and was 5.7% for the relative humidity. The CFD model and the boundary conditions were proved to be valid. The flow field existed obvious temperature gradient distribution, and the change of temperature was slowed down along with the increase of height before spraying. The temperature was decreased rapidly after spraying, especially for the temperature below the nozzles. The temperature in greenhouse was picked up gradually with the passage of the time, and the speed was positively related to the height.
出处
《江苏农业学报》
CSCD
北大核心
2013年第2期283-287,共5页
Jiangsu Journal of Agricultural Sciences
基金
国家自然科学基金项目(60971106)
关键词
温室
自然通风
喷雾降温
数值模拟
greenhouse
natural ventilation
spray cooling
numerical simulation
