Study On The Indoor Thermal Environmental Simulation And Optimal Design Of Caw Buiding Based On CFD And Study On Refrigeration System

The development of dairy farming in China depends on environmental factors.The growth and reproduction of cows depends on the environment.To create a comfortable environment for growth and reproduction,give the cow a good character,raise the utilization rate of cow to feed,improve the production efficiency of dairy farming and reduce production cost.In this study,the environmental quality of closed cow-house was simulated and evaluated.At present,holstein cow is the main breed of dairy cattle in China.Holstein cows have good thermal insulation because of their fur,and due to the lack of developed sweat glands,the heat released by evaporation is low,and the process of emulsion generation will produce more metabolic heat in the cow itself,so the cow of this breed is hardy to fear heat,the influence of high temperature and humidity in summer is significant,especially in the southern summer.The thermal environmental quality including wind speed,relative humidity,temparture and air age of cowshed plays an important role in cattle heath.Including harmful gas,high carbon dioxide concentration.The environmental condition of the cow house determines the health of their growth and the quality of milk products.The assessment of barn environment can analyse the internal environmental condition.This kind of analysis ofter an opportunity to modify the disadvantages and reduce economic losses.The simulation of the internal environmental condition can provide a guidence and reference for sudsequent researches.In this study,we accessed the internal environmental condition of a closed-barn,in Nanping.Fuzhou,using the technology of Computatiional Fluid Dynamic(CFD).This study can provide an effective method for the simulation of the thermal environment of the cowshed.We used the software named "Fluent" to simulate conditions of airflow field,temperature field,humidity field.The results of our simulations show that because of the cooling pad install in the Above the south wall,the airflow field is uneven distribution,Where the wind speed is large,the temperature is lower,The end temperature of the airflow field is higher.Humidity is inversely proportional to temperature.The humidity near the wet curtain is high,the humidity is reduced in the back because of the temperature rise.Studies have shown that this longitudinal ventilation mode cannot meet the requirement of the cow to the environment during the summer heat.So for the disadvantages of ventilation mode,we came up with a improved mode:put the wet curtain under the primary wet curtain,blow the cooled air directly into the cow.By comparing the improved model with the original model,we concluded that the wind speed is obviously even,the temperature drops appreciably near the cow body.