Study On The Indoor Thermal Environment Simulation Of Closed-laying Pheasantry Based On CFD

The laying hens culture industry in China has developed rapidly in recent years.In order to make the hens play excellent traits,so that their feed utilization rate can be improved,the production efficiency of laying hens is improved,and the production cost is reduced.We study the environmental quality of laying hens pheasantry.Because the laying hens have higher requirements on the production environment and heat stress is more likely to occur dramatically in summer,and the high temperature and high humidity climate in the southeast coastal areas have a significant impact on their production,the environmental quality of the closed hen houses in this study.Perform a simulation evaluation.The environment inside the laying house dramatically affects the production performance,health status,production safety and chicken farm profitability.Therefore,the internal environmental quality(wind speed,temperature,relative humidity)and harmful gas content and dust content of the pheasantry are important factors affecting the above problems.In high-density stacked pheasantris,there are widespread problems such as poor air circulation,uneven distribution and low ventilation efficiency.In this paper,computational fluid dynamics(CFD)technology is used to evaluate the thermal environment quality of laying pheasantry.The research method can firstly provide an effective method for simulating the thermal environment of the laying pheasantry,and secondly,it can provide effective theoretical basis and guidance for scientific design of the ventilation system and cooling system of the livestock house.This paper selects one of the most representative pheasantry in a modern laying hen yard in Luoyuan County,Fuzhou City,Fujian Province as the research object.A computational fluid dynamics is the theoretical basis to evaluate and simulate the environment inside the pheasantry.The research results are as follows: Taking the closed laying hens pheasantry in summer as the research object,the environment in the pheasantry(including wind speed,temperature,relative humidity,and air age distribution)was numerically simulated by Fluent software in CFD simulation.The simulation results show that the temperature in the pheasantry is relatively constant due to the opening of the wet curtain at the air inlet of the pheasantry,the wet curtain on both sides and the air outlet,and the wind speed tends to increase from the air inlet to the air outlet.The opening humidity of the wet curtain is generally high,and the air age shows a small situation in a region where the gas circulation is good.Due to the height of the laminated cage and the obstruction of the chicken itself,the air circulation is not smooth,so the air age in the high-rise cage is significantly larger than that in the middle and bottom cages.The temperature is relatively low in the place where the airflow speed is high,but the temperature is higher in the air outlet at the air outlet;the relative humidity is opposite to the temperature,and the air near the wet curtain is high in humidity due to the wet curtain,and the humidity is at the air outlet.Decreased,the relative humidity in the middle area is lower than that near the wet curtains on both sides.Since the chicken cage has a total of six floors and a high layer height,and the wind speed at the air inlet is lower than that at the air outlet,the top chicken cage and the bottom chicken cage have a lower wind speed than the middle layer chicken cage.This evaluation shows that the wet curtain cooling system can cool down in summer but is not effective due to excessive humidity and cannot meet the requirements.Therefore,in view of the deficiencies of the ventilation cooling method,this study proposes an improved way: adjusting the height of the front wet curtain windshield and the angle of opening so that the cooling air can flow smoothly.In addition,the relative humidity of the whole pheasantry is generally high.It is recommended to increase the distance between the wet curtain wall and the windshield wall as appropriate to achieve the purpose of reducing the overall relative humidity of the pheasantry.