Abstract: At present, most of the swine farms adopt reduce ventilation in winter to keep warm. In order to evalute the indoor air quality under this feeding model, this paper took weaned piglet house with natural ventilation as research object, and adopted CFD technology to run numerical simutation on air velocity, temperature, CO2 concentration in natural ventilated piglet house and on the basis of environment factor spot measurement. The simulation results showed that within piglets activity area, where the breathing level height was 0.4 m and wind speed was under 0.1 m/s. There was a large airflow stagnation area in the second half of the house, mainly due to the insufficient air ventilation, the fresh air was unable to penetrate the entire pig house. The temperature distribution range was 15~21℃, the average temperature round air inlet end was around 16℃; the average temperature inside the house was 20℃, average CO2 concentration was 0.16%~0.25%, with an average concentration of 0.19%. At 6 environmental measurement points, the relative error of airflow field ranged from 0.2%~30%. The temperature field error was 2%~13%. The relative error range of CO2 concentration was 4.3%~24.2%. The relative error range between measured value and simulation value was within the acceptable limits. The temperature and CO2 concentration in the shed were not within the environmental hygiene standards. The natural ventilation model could not meet the demands of weaned piglets for winter environment. The above results laid a foundation for effectively improving the feeding and management level, and realizing the maximization of economic benefits.

Key words: piglet shed, natural ventilation, CO2, numerical simulation

摘要： 目前大部分养猪场在冬季减少通风以进行保温，为了评估这种饲养方式下舍内空气质量状况，以自然通风方式的断奶仔猪舍为研究对象，在现场实测环境因子的基础上，采用CFD技术对自然通风仔猪舍内的气流速度、温度、CO2浓度进行数值模拟。由模拟结果可知:在仔猪活动范围内，在呼吸水平高度为0.4m的区域内风速在0.1 m/s以下，猪舍后半段存在大面积的气流停滞区，主要由于通风不足，导致新风无法贯穿整个猪舍；温度分布范围为15～21℃，进风口端猪体周围平均气温16℃，舍内平均温度20℃；CO2浓度在0.16％～0.25％，平均浓度为0.19％。在6个环境测点中气流场相对误差范围0.2％～30％，温度场误差范围2％～13％，CO2浓度相对误差范围4.3％～24.2％，实测值与模拟值的相对误差范围在可接受的范围内。舍内的温度、CO2浓度均不在环境卫生标准之内，自然通风方式无法满足断奶仔猪对冬季环境的需求。上述结果为有效提高饲养管理水平，实现经济效益的最大化奠定了基础。

关键词: 仔猪舍, 自然通风, CO2, 数值模拟