摘要
对上下冲击式高效鼓风冻结装置建立数学物理模型,使用CFD软件对速冻装置内静压箱和贴近网带上下方的速度场进行数值模拟。计算中将位于上下均风孔板间的网带作为多孔介质处理。研究结果表明,增设导流板可改进静压箱拐角处气流组织的均匀性;扩大冻结区两侧隔板和网带侧边形成的通道,也可以改进局部区域流场的均匀性,这种改进方法需要减小网带宽度或加大装置整体宽度。因此,要保证设备的冻结能力,则需综合考虑风速、网带尺寸等对冻结能力的共同影响。此外,网带位置会影响周围气体流场分布,网带距下方送风口距离在20 mm-30 mm之间时,可以保证风速在3 m/s左右,且均匀性较好。通过测试实验验证了模型建立的合理性及计算结果的准确性。
The physical and mathematical models were established for impingement freezer. Numerical simulation of velocity field was carried out on static pressure tank and the area near mesh belt using CFD. The mesh belt was regarded as poriferous medium. It was indicated that diversion plates could improve air distribution in the corner of static pressure tank. It could also improve air distribution by expanding the channel between clapboard and the side of mesh belt, which bring on decreasing the width of mesh belt or increasing the width of freezer. The common influence of freezing capability, such as air velocity and size of mesh belt, should be considered to ensure the freezing capability. The place of mesh belt affected air flow around it as well. The best region for mesh belt away from lower gas distributing board was 20 mm - 30 mm, where the air distribution was optimal. The reliability of the simulation was certificated with the experiments.
出处
《低温工程》
CAS
CSCD
北大核心
2008年第6期45-50,共6页
Cryogenics
基金
上海市科技兴农重点攻关项目(沪农科攻字(2006)第7-1字)
上海市重点学科建设项目(项目编号:T1102)
关键词
数值模拟
气流组织
静压箱
网带
速冻装置
numerical simulation
air distribution
static pressure tank
mesh belt
freezer
