【作者】 陈忠购；

【导师】 张天柱；

【作者基本信息】 中国农业大学 ， 农业生物环境与能源工程， 2004， 硕士

【摘要】 本论文对北京地区无植物条件下采用湿帘风机降温系统的华北型连栋塑料温室进行了实验研究，在实验研究的基础上，采用CFD方法建立无植物条件下采用湿帘风机降温系统的华北型连栋塑料温室的CFD理论模型，应用CFD模型模拟了不同湿帘高度和安装高度情况下华北型连栋塑料温室流场和温度场的分布情况，并与实验测试结果进行对比分析。本文还利用所建立的CFD模型对华北型连栋塑料温室在华北地区各地的使用进行了研究。分析了温室长度，出口风速和湿帘安装高度对华北地区各地华北型连栋塑料温室机械通风的影响。 针对实验温室在不同湿帘高度和安装高度情况下的温室环境进行了实地测量，分析了华北型连栋塑料温室在不同实验方案下的夏季通风降温效果。试验结果表明：采用湿帘风机降温系统的华北型连栋塑料温室在我国华北地区的炎热季节，能够有效地降低温室室内的空气温度，在实验条件下，可以使华北型连栋塑料温室内平均空气温度比室外温度降低5.62℃。实验结果还表明，在相同实验条件下，增加入口湿帘面积，可以有效地增加温室的可控距离；提高湿帘安装高度温室可控距离增加不明显。 在实验研究的基础上，本文利用CFD方法建立了华北型连栋塑料温室实物大小的三维CFD模型，采用稳态和标准k-ε湍流模型对实验温室在不同湿帘高度和安装高度情况下的温室环境进行了CFD模拟，预测了实验温室内部的流场和温度场的分布情况。并将计算结果与实验测量结果进行了比较，实验值和计算值吻合的比较好，由此验证了选用的CFD软件对华北型连栋塑料温室进行数值模拟的可行性和有效性。 并利用所建立的华北型连栋塑料温室的CFD模型，对华北地区各主要地区气候条件下，不同温室长度、湿帘高度、湿帘安装高度的华北型连栋塑料温室夏季通风降温情况进行了CFD研究。给出了华北型连栋塑料温室在华北地区各主要地区适宜采用的温室长度、湿帘高度、湿帘安装高度。更多还原

【Abstract】 The cooling effects of mechanical ventilation of Huaber-type multispan plastic greenhouse without plant are experimentally studied in summer. Under the experimental conditions,A three dimensional CFD model for mechanically ventilated Huaber-type multispan plastic greenhouse is established. And the 3-D CFD model is used to forecast the velocity and temperature distributions in a mechanically ventilated Huaber-type multispan plastic greenhouse, the predictions were checked against the measurements inside the experimental glasshouse and CFD was considered practicable. The 3-D CFD model is developed to simulate the cooling effects of mechanically ventilated Huaber-type multispan plastic greenhouse in Huabei area. Subsequently, CFD was used to investigate the influence of the length of the greenhouse, exit air velocity and cooling pad position on the internal airflow pattern in the same house.Under the experimental conditions, the average indoor air temperature is 5.62# lower than that of without mechanical ventilation, the largest air temperature difference is 10-12#.The result show the decreasing of entry air velocity and the increasing of cooling pad position have a advantage in the greenhouse cooling.Under the experimental conditions,A three dimensional CFD model for mechanically ventilated Huaber-type multispan plastic greenhouse is established.The model was steady state,the standard k- model was used to simulate turbulence.Then use the 3-D CFD model to forecast the the internal airflow pattern with different sizes and position of the cooling pad. the predictions were checked against the measurements inside the experimental glasshouse and CFD was considered practicable.The Applications of computational fluid dynamics in mechanically ventilated glasshouse research are studied with the checked CFD model. Different greenhouse length, cooling pad sizes and position are taken in account. The controllable distance of the Huaber-type multispan plastic greenhouse in Huabei area is presented.更多还原