浅圆仓环壁通风降温系统的性能试验与风道设置优化  

Performance test of ringed ducts system for ventilating and cooling in large diameter squat silos and air flue setting opitimization

作　　者：陈雁[1] 王子嘉 付常青 崔伟华[1] Chen Yan;Wang Zijia;Fu Changqing;Cui Weihua(College of Civil Engineering and Architecture,Henan University of Technology,Zhengzhou 450001,China)

机构地区：[1]河南工业大学土木工程学院

出　　处：《农业工程学报》2019年第17期285-292,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家重点研发计划项目(2016YFD0401601)

摘　　要：通风降温是实现粮食保质储藏的重要措施。以大直径浅圆仓为研究对象,建立了环壁分层通风快速降温实验系统,进行了不同工况的降温实验,研究在粮食初入仓阶段的降温过程中,影响粮堆内温度、水分均匀性的因素。结果表明:外界热环境对降温速度有明显影响,过渡季高温期工况和夏季工况下,降温速度分别为0.43和0.16℃/h,纵向层间温差分别为0.5和1.6℃,降温后粮堆平均温度为17.24和22.76℃,分别达到准低温储粮(20℃)和常温储粮(25℃)的范围。采用露点以上温度进行送风,降温过程粮堆内空气相对湿度较为稳定,波动幅度在5%以内。采用计算流体力学(computer fluent dynamic,CFD)方法对环壁风道的配置进行了模拟研究,模拟结果与实验结果的平均相对误差为6.43%,证实了模拟的合理性与准确性。模拟结果表明,环壁风道上移后,增强了上部粮堆的降温效果,提高了整体降温速度,改善了粮堆温度的均匀性。Ventilating and cooling are popular measures to achieve high quality storage for cereals.In large diameter squat silos with high-moisture cereal,the heat gain conducted through the building envelope would accumulate in the cereal bulk if only conventional ventilation was applied.Normal ventilating modes,such as slots under the floor or ducts on the ground,could not provide an airflow organization meeting the temperature and moisture distribution demand in the large diameter squat silo,because the size and shape of the new-style was different from that of the exited.In this paper a ringed ducts experiment system was set up to study the ventilating and cooling effect for large diameter squat silos.Considering the different seasons for storage in practice,experiments were carried out in 2 different climate conditions:hot season mode and warm season mode,corresponding to spring/autumn and summer,respectively.The experiment included 3 parts:1)bulk preheating-the cereal and the ambient temperatures were brought to a set initial value;2)constant thermal environment-the radiator was turned on,so that the top of the silo was heated by uniform radiation,and the ambient temperature around the silo was constant in a preset range by feeding warm air;3)cooling-the cold air was supplied into the silo at a temperature lower than that of the cereal until the average bulk temperature was stable.During the experiment process,the air velocity at the supply outlet in the vertical main pipe was 2.01-2.05 m/s,that was,an air supply volume of 6.58-6.67 m3/h.The ambient temperature and relative humidity was at the range of 25.59-28.48℃and 46.3%-48.7%for warm season mode,and the range of 29.32-31.05℃and 37.5%-39.2%for hot season mode.The initial temperature was approximately 27℃in both modes.The effective temperature difference was 5 and 7℃in warm season mode and hot season mode,respectively,considering 2 different dew-point temperatures.The results showed that external thermal environment had an influential effect on time spendin

关 键 词：降温 通风 温度 大直径浅圆仓 环壁风道 计算流体力学 

分 类 号：TS210.2[轻工技术与工程—粮食、油脂及植物蛋白工程] TB69[轻工技术与工程—食品科学与工程]