北方寒冷地区猪舍通风流场模拟研究

Simulation Study on Ventilation Flow Field of Pig House in Northern Cold Region

内蒙古等北方寒冷地区存在早晚温差大、冬季时间长且气温低的特点,而畜禽舍的保温和通风能力不足制约了北方寒冷地区养猪场的发展。为了研究北方寒冷地区猪舍空气流场的分布规律,用于指导猪舍的改进和优化设计,以内蒙古农业大学科技园区母猪舍为研究对象,采用计算流体动态模拟CFD(Computational Fluid Dynamics)方法 ,对猪舍横向与纵向两种通风方式进行空气流场、温度场变化规律三维数值模拟研究。模拟结果表明:纵向通风方式下,空气进入后在猪舍中间形成一股主气流,出口速度较大,其他位置速度值较小,出口温度较高;横向通风方式下,形成多个主气流,在挡板作用下出现涡流,同时靠近出风口位置速度比较大,卧床内温度分布比较高;两种通风模式对比下,横向通风时气流均匀性比纵向通风差,死角多但是温度变化小,适合寒冷北方保温。对横向通风的模拟值与实测值的现场试验对比结果表明:21个测点测试值与模拟值平均相对误差的平均值为12.46%。这说明,现场实测与数值模拟有较好的吻合度。数值模拟优化后加置3个挡风板,气流平均速度增大27.8%,气流不均匀性降低53.2%。该研究可为北方寒冷地区猪舍结构优化设计和环境调控提供理论依据。

Inner Mongolia and other cold areas in the north there is sooner or later the temperature difference,the winter is long and low temperature characteristics,and livestock and poultry house insulation and ventilation capacity of the northern cold areas restricted the development of pig farms.In order to study the distribution law of the air flow field in the cold farms of the northern region,to guide the improvement and optimization design of the pig house,the sow shed of the Inner Mongolia Agricultural University Science Park was used as the research object.The CFD（computational fluid dynamics） The three-dimensional numerical simulation of the air flow field and the temperature field in the horizontal and vertical ventilation modes of the pig was carried out.The simulation results show that in the longitudinal ventilation mode,after the air enters,the main airflow is formed in the middle of the pig house,the export speed is larger,the other position velocity value is smaller and the outlet temperature is higher; when the horizontal ventilation mode is formed.In the role of the baffle under the eddy current,while the speed near the outlet position is relatively large,the temperature distribution within the bed is relatively high; two ventilation mode contrast,the horizontal ventilation uniformity of airflow than the vertical ventilation is poor,but the temperature change is small,Suitable for cold north insulation.The comparison between the simulated values of the lateral ventilation and the measured values of the measured values shows that the average relative error between the 21 test points and the simulated values is 12.46%,which indicates that the field measurements have good agreement with the numerical simulation.After the numerical simulation,three windshields were added,the average air velocity increased by 27.8%,and the airflow nonuniformity was reduced by 53.2%.This study can provide the theoretical basis for the optimal design and environmental regulation of pig house structure in the cold area of Northern China.