89 / 2025-06-20 10:31:28

Numerical study and optimization of thermal environment regulation in poultry house ventilation systems

CFD, Poultry house, Aerosol, Thermal comfort, Response surface optimization

2. 畜禽设施养殖工艺与装备系统 > （2）立体多层饲养设施与装备系统

In response to the challenges of regulating the thermal environment and the high risk of biological aerosol transmission in closed-scale poultry farming systems, this study focuses on ventilation optimization in poultry houses based on computational fluid dynamics (CFD). In order to study the effects of different fan positions on the thermal comfort and pathogen dispersion in the chicken house, we selected four classical fan combinations, and analyzed the flow field characteristics under different fan combinations by numerical simulation, and systematically evaluated the effects of different fan combinations on the characteristics of the airflow organization and the diffusion behavior of bioaerosols in the house. Firstly, a total of 48 injection sources were set up in the front, middle and back areas of the chicken house, and the flow lines of the airflow were colored by using the length of residence of aerosol particles as a variable, which proved that the different fan combination designs had a significant effect on the propagation of aerosols. Subsequently, the residence time of aerosols in the house was counted, and it was verified that successive turning on of fans in adjacent positions could increase the air flow rate, promote heat exchange and accelerate the discharge of aerosols. After validation of the CFD model, the optimal fan opening method was determined. Subsequently, the control process of the ventilation system was optimized to improve the comfort index of laying hens. For the study of the ventilation system, the optimization of individual parameters ignores the interaction between the parameters, which can easily lead to the emergence of extreme environmental conditions; the consideration of all the parameters affecting the performance of the ventilation system requires a large number of CFD simulations, which is a time-consuming computational process. Therefore, a DOE program was introduced into the CFD simulation to analyze the interaction between inputs and outputs, which can reduce the consumption of computational resources. In this study, fan efficiency, air guide opening angle and inlet air temperature were used as test factors, and the percentage of thermal comfort zone was used as the response index. A three-factor and three-level response surface simulation experiment was designed to evaluate the poultry house ventilation process. The optimization process consists of three steps: (1) using the experimental design Box-Behnken Design (BBD) methodology to obtain the design points; (2) response surface methodology (RSM) to react to the relationship between the control factors and the response results; and (3) obtaining the optimal design by means of a response optimizer. The experimental results show that the optimal combination of operating parameters of the ventilation system is: fan efficiency (93%), air guide plate angle (9.85°) and inlet air temperature (19.09°C), and the optimization yields a maximum thermal comfort zone percentage of 90.59%.The average thermal comfort zone percentage obtained from the five validation experiments is 89.02%, and the error with the prediction of the thermal comfort zone percentage obtained is 1.73%. The results of the study revealed the impact of the combination of intensive poultry house fan opening on the airflow path, and established a multi-parameter optimization method of environmental control, which provides a theoretical basis and technical reference for the optimal design of the environmental control system in poultry farms.