Numerical Simulation Of Mechanically Ventilated Huabei-Type Multispan Plastic Greenhouse Using CFX4.3

Greenhouse is one of the high gardening establishment for planting.Today, greenhouse is required not only to preserve heat in winter but alsocan control the temperature in summer. Natural ventilation andmechanical ventilation are two main ways for the greenhouse cooling.Using mechanical ventilation along with the cooling pad can make goodcooling effect and control temperature automatically. Until now it is notfound to study the couple effect of mechanical ventilation and solarradiation in greenhouse. Mass and heat transfer in the mechanically ventilated Huabei-Typemultispan plastic greenhouse without plants is numerically simulatedusing commercial software of CFD (Computational Fluid Dynamics),CFX4.3 in this paper. The computation gives related computing velocityand temperature fields and they are compared with the measured values.Besides, it is also discussed that the effect of the entry air velocity and theheight of cooling pad on the controllable distance of the studiedgreenhouses and the influence of the inside cover in greenhouse. The results indicate that during the torridity summer naturalventilation can not satisfied the temperature requirement in greenhouse, II北京化工大学硕士学位论文so it is necessary to use the mechanical ventilation. The computing resultsare well matched with the experiment. The temperature in greenhouse canbe controlled by adjusting the entry air velocity and the height of coolingpad. Inner curtain in greenhouse can make even more cooling effect intorridity summer.