隧道式液氮速冻机冷冻性能研究及喷嘴分布结构优化  

Research on freezing performance of tunnel type liquid nitrogen freezer and optimization of nozzle distribution structure

作　　者：杨晓惠[1] 贾志斌 杨松[1] 杨木豪 廖春平 Yang Xiaohui;Jia Zhibin;Yang Song;Yang Muhao;Liao Chunping(School of Mechanical and Electrical Engineering,Southwest Petroleum University,Chengdu 610500,China;Chengdu Cryostech Equipment Co.,Ltd.Chengdu 611230,China)

机构地区：[1]西南石油大学机电工程学院,成都610500 [2]成都科莱斯低温设备有限公司,成都611230

出　　处：《低温工程》2023年第5期53-60,88,共9页Cryogenics

基　　金：四川省自然科学基金(No.2022 NSFSC1116)。

摘　　要：为了提高隧道式液氮速冻机的冷冻均匀性,采用数值模拟结合实验验证的方法,研究了喷嘴分布方式和分布参数对冷冻性能的影响,并确定了最佳的分布参数。结果表明:原有、矩形、环形和组合4种喷嘴分布方式下各测点的风速基本一致;与原有喷嘴分布方式相比,矩形、环形和组合3种改进喷嘴分布方式均有效提高了冷冻腔内温度场分布的均匀性,所得产品表面的Nu分布更均匀;环形分布时的平均Nu提高了8.3%,换热强度最大;平均Nu随喷嘴分布直径的增加呈先增大后减小的趋势,而随垂直间距的增加单调增大,分布直径的影响程度大于垂直间距,喷嘴角度的影响不显著;通过极差分析确定出最佳的喷嘴环形分布尺寸,即分布直径0.78 m,喷嘴角度0°,垂直间距0.05 m。To enhance the freezing uniformity of tunnel-type liquid nitrogen quick freezers,this study employs numerical simulation and experimental verification to study the influence of nozzle distribution modes and distribution parameters on the freezing performance,and determines the optimal distribution parameters.The results indicate that the wind velocities at each measuring point exhibit a high degree of consistency across the four nozzle distribution modes,namely original,rectangular,annular and combined nozzles.Compared to the original nozzle distribution method,the three improved methods of rectangular,annular and combined nozzles all effectively enhance the uniformity of temperature field distribution in the freezing chamber,resulting in a more even Nu distribution on the product surface.The average Nu of the annular distribution increases by 8.3%,exhibiting the highest heat transfer intensity among them.The average Nu shows a trend of first increasing and then decreasing with the increase of nozzle distribution circle diameter,while monotonically increasing with the increase of vertical spacing.The influence of distribution circle diameter is greater than that of vertical spacing,while the influence of nozzle angle on the average Nu is not significant.The optimal size for the annular distribution of nozzles is determined through range analysis,resulting in a distribution diameter of 0.78 m,nozzle angle of 0°,and vertical spacing of 0.05 m.

关 键 词：隧道式液氮速冻机 喷嘴分布 数值模拟 努塞尔数 正交试验 

分 类 号：TB657.5[一般工业技术—制冷工程]