Research On Simulation And Optimization Of Environmental Parameters Of Finishing Pig House Based On CFD

With the development of China’s pig industry,the continuous improvement of breeding scale and intensive degree,the pig industry has basically solved the problems of traditional breeding,nutrition,epidemic prevention and other production technologies,and the breeding environment has become one of the most important factors restricting the production and development of China’s pig industry.Due to the lack of professional technical guidance,many small and medium-sized pig houses in China are still built according to the standards of civil buildings,which are not designed according to the physiological characteristics of pigs.As a result,the wind speed,temperature and humidity,harmful gas concentration and other aspects of the pig house are not up to the standard,which seriously affects the growth and health of pigs.In this paper,on the basis of field measurement data,using ANSYS 18.0 software to simulate the environmental parameters of a typical fattening pigsty in Taigu,Shanxi Province.On the one hand,this study can verify the feasibility of CFD technology in piggery environment simulation,and provide an effective method for piggery environment simulation;on the other hand,it can find the existing problems of piggery environment according to the simulation results,and put forward the corresponding optimization scheme.The main conclusions are as follows1)According to the measured data,a three-dimensional model of the piggery was established,and the airflow field,temperature field and CO₂ concentration field of the piggery were simulated and analyzed.The simulation results were compared with the measured data.The results showed that the maximum relative error of airflow field was 20.3%,the maximum relative error of temperature field was 7.9%,and the maximum relative error of CO₂ concentration field was 21.2%.The simulation results fit well with the measured results,which proves that CFD technology is feasible in the simulation of environmental parameters of pigsty.2)Through the measured results and simulation results of the fattening pigsty,the following problems exist in the pigsty: the ventilation in the pigsty is seriously insufficient,there are air flow dead zones in many places,and the overall wind speed is between 0.17m/s and 0.5m/s;the temperature in the corridor of the pigsty is relatively low,and the temperature in the pigsty is higher,and the overall temperature is between32 ℃ and 35 ℃;the CO₂ concentration near the ground of the pigsty is between 1600 ppm and 2000 ppm.The wind speed,temperature and CO₂ concentration in the piggery can not meet the environmental requirements of pigs.3)According to the existing problems,two optimization schemes of transverse ventilation and longitudinal ventilation are proposed and simulated.The simulation results show that the two schemes can improve the airflow velocity,temperature and CO₂ concentration distribution,and the improvement effect of longitudinal ventilation is better.