【摘要】 我国南方地区夏季长期高温,严重影响了温室作物生长。为了提高降温效果且减少通风能耗,需要优化温室机械通风系统的设计参数和控制方法。以南方地区典型的连栋塑料温室为研究对象,针对温室机械通风,建立了三维全尺度瞬态及稳态计算流体力学仿真模型。通过在温室内、外均匀布置温、湿度和光照传感器,测量机械通风引起的温室内气温变化和分布,用实验验证了仿真模型瞬态和稳态计算的准确性和有效性。通过仿真模型模拟了室外高温条件下的风机数量、温室长度、入口温度及环境温度变化等参数对机械通风降温效果的影响程度,并模拟了不同数量风机启闭控制的降温效果。本文提供的控制策略最高可减少约60%的能源消耗,而植物冠层平均温度仅升高0.21℃。更多还原

【Abstract】 Due to the long-term summer in southern China,the crops in greenhouses suffer from high temperature seriously. In order to improve the cooling effect and reduce the energy consumption of ventilation,it is necessary to optimize the design and control strategy for the mechanical ventilation system of greenhouses. A full-scale 3-D transient and steady CFD simulation model was established for a typical multi-span plastic greenhouse in southern China. By using evenly distributed temperature,humidity and light sensors inside and outside the greenhouse,the variation and distribution of temperature driven by the mechanical ventilation were measured. The comparison between the experimental and simulation results showed that the CFD model was valid. Under the high ambient temperature,the CFD model was carried out to investigate the impact of design parameters,such as the number of working fans,length of greenhouse, inlet temperature and outside environment temperature, on cooling effect of mechanical ventilation. And then the cooling effect under different control strategies of mechanical ventilation was simulated to reduce the energy consumption. The proposed CFD model can provide optimized parameters for the design and control of multi-span plastic greenhouse mechanical ventilation in summer,which can be applied to improve the cooling effect and reduce energy consumption of ventilation.更多还原