| With the outbreak of African swine fever and other swine diseases,biosafety problems in large-scale pig farms have attracted more and more attention from breeding enterprises.Pathogens carried by live pig transport vehicles is the main way to cause the transmission of pig epidemics.Therefore,cleaning and disinfection of live pig transport vehicles is an important guarantee for effectively killing pathogens and cutting off the spread of pig epidemics.For most pathogens are sensitive to high temperature,high-temperature drying of live pig transport vehicles can effectively kill pathogens.The three-layer fence type live pig transfer vehicle is a commonly used vehicle type in the actual production process.The in-depth research on the drying and disinfection technology of the three-layer fence type live pig transfer vehicle has important engineering application value.Taking the new live pig transfer vehicle drying room as the research object,the accuracy of drying room model is verified by field test and numerical simulation of drying room containing ordinary truck.Subsequently,the drying room model with a three-layer fence type live pig transfer vehicle was established,the optimization research under the condition of constant heat supply and the change of heat supply was carried out in turn,and a comparative study of drying rooms with six air distribution forms was carried out,so that the surface temperature of the car body can reach more than 70℃,and the temperature distribution is relatively uniform,which realizes the optimization research on the drying technology of the three-layer fence type live pig transfer vehicle.The main research results are as follows:(1)Field tests and numerical simulations were carried out on the drying room containing the ordinary truck,and the simulation results are in good agreement with the measure,which proves that drying room model has high accuracy.(2)Under the existing air supply and heat supply mode,numerical simulation was carried out on the drying room containing the three-layer fence type live pig transfer vehicle.The research and analysis showed that the distribution of the velocity field and the temperature field on the surface of the car body is uneven,and the wind speed is small;Most of the surface temperatures does not reach 70℃.(3)Under the condition of constant heat supply,the orthogonal experimental design method was adopted,the spacing and height difference of the rear fans,the spacing,height and diameter of the side air inlets were used as the optimization parameters,and the average temperature and the non-uniformity coefficient were used as the optimization goals to determine the optimal combination scheme.Through numerical simulation research,the optimal scheme achieved that the surface temperature of most of the car body reaches 70℃,but a small part of the first floor of the pig cage and the chassis of the vehicle does not meet the drying temperature requirements.(4)Under the condition of changing heat supply,the orthogonal experimental design method was adopted,the circulating air volume of the rear fan,the air velocity and temperature of the side air inlets were used as the optimization parameters,and the average temperature and the non-uniformity coefficient were used as the optimization goals to determine the optimal combination scheme.Through numerical simulation research,the optimal scheme achieved that the surface temperature of the car body could reach above 70℃,but the uniformity of temperature distribution on the pig cage floor of the first layer carriage,vehicle chassis and tire decreased.(5)Comparing and analyzing the drying rooms under the six air distribution forms,it was found that when the average temperature and the non-uniformity coefficient are comprehensively considered,the temperature distribution of car body surface can be effectively improved by using two ways of the lower side to the opposite side of the upper gyrus and the bilateral lower to bilateral upper gyrus. |
PDF Full Text Request