Research On Winter Regulation Scheme Of Vertical Ventilation System Of Dairy Barn In Severe Cold Area

As people's demand for dairy products continues to increase,the feeding methods of dairy cows have gradually developed towards large-scale and intensive development.The quality of dairy products largely depends on the environmental quality of the dairy barn.The airflow velocity,temperature,relative humidity and concentration of harmful gases in the dairy barn are the key factors affecting the health and production performance of the cows.Aiming at the problems of the current closed dairy cow house in northern my country that the contradiction between ventilation and heat preservation results in the long-term growth of cows in a low temperature and high humidity environment and the low level of automation control,this paper selects a closed lactating cow house in Daqing City Benkang Animal Husbandry for the experiment In the cow house,continuous field environmental testing was carried out on the internal temperature,relative humidity,wind speed,etc.of the cow house.The physical model of the cow house was drawn using Solid Works software,and the temperature and humidity inside the house were numerically simulated by CFD software.Based on this,a plan for environmental regulation of the dairy barn was put forward,and the results of the study showed that:(1)Continuous field tests were carried out on the enclosed dairy barn,and the changes and distribution of environmental parameters in the barn were obtained.The results show that the cows have been growing in a low temperature and high humidity environment for a long time.During the test,the average temperature outside the house was-19.59?,the average relative humidity was 34.4%,the average temperature inside the house was 1.65?,and the average relative humidity was 94.6%.The inside of the house was on the same cross-section.The upper temperature difference is not big.(2)CFD numerical simulation was carried out on the experimental cow house.The results showed that the airflow in the house enters from the gate,spreads from the feeding channel to the bed on both sides and the wind speed gradually decreases.After the cold air enters the house and exchanges heat and mass with the cow body,Under the action of heat pressure,there is a skylight to remove;at the same time,a model test of vertical ventilation is carried out.The test results show that vertical ventilation technology can quickly remove moisture from the model.(3)The overall design of the system is carried out,the design principles are put forward,and the system is determined to be composed of a control module,a data acquisition module,an execution module,and a power supply module.The hardware and software parts of the system are designed,and the program design of the control parameters is proposed.The system has been debugged for two consecutive days.After testing,the system can meet the design requirements.(4)Three fan operating conditions were designed and compared and analyzed with the original conditions of temperature and humidity in the house.When the ceiling fan fans in the house were operated at 50 Hz and 45 Hz,the relative humidity in the house was significantly improved,but the relative humidity in the house was significantly improved.The temperature drops significantly.When the ceiling fan is running at 40 Hz,the temperature in the house is in a suitable environment,but the relative humidity is not improved significantly.Through comparison,the optimization plan for opening the ceiling fan in the house is determined,and the experimental verification shows that the optimization plan can effectively improve the environment in the house.