基于CFD的蛋鸭舍内环境模拟分析与验证

为优化4层层叠式笼养鸭舍舍内环境,基于计算流体动力学(computational fluid dynamics,CFD)对鸭舍内气流场、温度场及CO_2浓度场进行模拟。将笼架简化,考虑其对气流的阻挡作用,将鸭笼及鸭只视为多孔介质。模拟结果显示,进风口为湿帘时,侧墙湿帘与端墙之间存在通风死区,风速低于0.5 m·s~(-1)。进风口为通风小窗时,鸭舍未安装通风小窗区域风速小,CO_2浓度大。改变纵墙湿帘位置对鸭舍结构进行改进,改进后气流不均匀系数降低了17%。改进通风小窗布置发现,提升通风小窗分布均匀性显著降低舍内温差;提升通风小窗安装高度将显著降低舍内CO_2浓度。该研究可为蛋鸭舍结构设计提供参考。

Simulation of airflow field and temperature field of laying duck house based on CFD

In order to optimize the environment of closed duck house with 4-layer stacked cages, the airflow, temperature and CO₂ concentration field in the duck house were simulated based on computational fluid dynamics (CFD).The flow was assumed 3D, steady state and turbulent. Simplified the feeding equipment and highlighted its blocking effect on the airflow. Duck cages and ducks were considered as porous media. The simulation results show that when the inlet is evaporating cooling pad, the average airflow velocity in the front of the duck house is lower than 0.5m·s^-1 in the length direction. The average airflow velocity of the middle aisle is the highest among the aisles. When the air inlet is ventilation window, the area without it has low air velocity and high CO₂ concentration. The structure of duck house was improved by changing the position of evaporating cooling pads on side wall, and the coefficient of non-uniformity of airflow was reduced by 17%. By improving the layout of ventilation windows, it is found that the uniformity of the distribution of the ventilation windows is significant to the environment, and increasing the installation height of the ventilation windows will significantly reduce the CO₂ concentration in the building. The CFD model was verified by comparison with the field experimental results at the same locations. And this study can provide references for the structural design of laying duck house.