Research On Ventilation Environment Of Pigsty In Northern Cold Area Based On CFD

According to the characteristics of small and medium-sized pig breeding in the northern cold area,this paper takes the pig house of Hai Liutu of Inner Mongolia Agricultural University and the Sa Laqi science and Technology Park as the research object.The design of monitoring system and CFD simulation and experimental verification of airflow and temperature field are carried out.The relationship between wind speed,ventilation time,NH₃ concentration and temperature in piggery is also obtained.It will provide theoretical basis for the pig welfare culture in the cold area of North China.Based on ZIGBEE wireless network technology and configuration MCGS software,pigsty environment monitoring system is designed.It includes four parts:boot interface,monitoring interface,parameter setting interface,save disk browsing interface.Through experiment and debugging,we realized the wireless monitoring of pig house's environmental information parameters.Using this monitoring system,we collected data of NH₃ concentration and temperature in pig farms at different wind speeds.At the same time,using MATLAB software to process the collected data,we get the fitting curve and3D fitting surface between wind speed,ventilation time,NH₃ concentration and temperature.The fitting equations of different fitting curves and 3D surfaces are also obtained.In addition,based on the CFD theory,the flow field and temperature field under different ventilation modes of piggery were studied,and the visualization of measured data was realized.The distribution of air flow and temperature field and advantages and disadvantages of each ventilation mode were analyzed,and ventilation optimization simulation and field test were carried out.The following conclusions are obtained:?1?The environment monitoring system of pig is stable and reliable.It effectively solves the problems of high cost and complex problem,and realizes the wireless monitoring of the environmental information of piggery.?2?When the wind speed of Hai Liutu pig house inlet is 0.5m/s,it can ensure that NH₃ concentration is controlled within a reasonable range,and the temperature drop is low.?3?The CFD simulation technology can be used as a tool to evaluate the piggery environment by comparing the measured data with the simulated data.?4?The Sa Laqi pig house was reformed by the way of adding baffles.It was found that the airflow uniformity increased by 53.2%and the comfort degree of the pig was improved.