有缓冲间湿帘-风机系统对兔舍环境调控效果研究

Environmental Control of Fan-pad Evaporative Cooling System with Buffer Rooms

为实现一套系统满足全年环境调控需求,试验选取两栋安装有“有缓冲间湿帘-风机系统”的兔舍,冬季其中一栋舍一台风机安装变频器,另一栋舍全为定速风机。结果表明,冬季定速风机常速间歇通风的兔舍导向板进风口的风速为1.8 m/s,进入舍内风速降至0.1m/s,每日首次开启风机10 min CO_2浓度降低67.2%,间歇通风每次温度平均降低0.8℃;使用变频风机低速持续通风的兔舍,导向板进风口风速0.2m/s,进入舍内风速降到了0.05m/s,开启风机CO_2浓度降低59.5%,温度降低0.3℃;两舍缓冲间预热能够分别提升气流温度2℃、1.4℃。夏季在舍外温度32.4~38.2℃时,舍内温度能维持在26℃左右,温度降幅为9.0℃,舍内温湿指数（THI）为25.9;外墙湿帘的降温效率为87.2%,内墙湿帘的降温效率为0。夏季缓冲间和进风口气流导向能够显著降低入舍风速（外墙湿帘过帘风速0.8m/s,导向板进风口风速1.9m/s,进入舍内风速0.3m/s）,且舍内气流分布均匀。综合环境指标说明,有缓冲间的湿帘-风机纵向通风系统克服了冬夏季进风端风速大、温度低的弊端,但舍内隔墙上的湿帘无降温潜力,建议去掉第一缓冲间及内墙湿帘。

In this study, two rabbit houses with ＂fan-pad evaporative cooling system with two air buff- er rooms＂ were chosen and their environment controlling effects were studied both in winter and summer. In winter, one of the rabbit house was given long time low speed ventilation scheme achieved by a fan fre- quency converter , and the other rabbit house were all set with constant speed fans and intermittent venti- lation. Make the system available for environment control in all seasons. The results in winter showed that the air speed of 1.8 m/s in deflector inlet in rabbit house with constant speed -intermittent ventilation de- creased to 0.1 m/s when entering the house, and with an average of 67.2% decrease in CO2 concentration and 0.8 ℃ decrease in temperature after the first 10-minutes running of ventilation every day. The air speed of 0.2m/s in defector inlet in rabbit house with long time low speed ventilation scheme decreased to O. 05m/s when entering the house, and with an average of 59.5% decrease in C02 concentration and 0. 3 ℃ decrease in temperature. After preheating with buffering rooms, the air temperatures can be increased 2 ℃ and 1.4 ℃ in two rabbit houses separately. In summer, the temperature inside rabbit house can be main- tained around 26 ℃, with an average 9 ℃ temperature decrease and an THI of 25.9 when the outside air temperature were in the range of 32.4~38.2 ℃. The cooling efficiencies of cooling pads on the outer wall are 87.46% and 87.76%, while that of the interior partition wall are 0. Air speed can be significantly de- creased （from 0.8m/s of the outer wall cooling pad and 1.9 m/s of the inlet to 0.3 m/s near rabbit cage）, and evenly distributed after going through the buffer room and air deflector. Comprehensive environment index shows that the cooling pad-fan system with buffering room overcomes the traditional disadvantage of high air speed and low air temperature at the end inlet, and meets both the requirements of keeping room temperature and ventilation in winter as well as cooling in summer. Cooling pads on interior partition wall have no cooling potential and are not necessary for this system.