两种喷嘴结构对冲击式速冻机流场及换热特征的影响  

Influence of two ddifferent nnozzle fforms on the flow ffield and heat transferring characteristics of qquick freezer

作　　者：王金锋[1,2,3,4,5] 李文俊 谢晶[1,2,3,4,5] 杨大章 柳雨嫣[1,2] 陆卫华 杨晓燕 WANG Jin-feng1,2,3,4,5,LI Wen-jun1,2, XIE Jing1,2,3,4,5, YANG Da-zhang1,2,3,4,5,LIU Yu-yan1,2, LU Wei-hua6, YANG Xiao -yan6(1. College of Food Sciences ＆ Technology, Shanghai Ocean University, Shanghai 201306, （＇hina ; 2. Quality Supervision, Inspection and Testing Center for Cold Storage and Refrigeration Equipment, Ministry of Agriculture Shanghai 201306, China; 3. Shanghai Professional Technology Service Platform on Cold Chain Equipment Performance and Energy Saving Evaluation, Shanghai 201306, China; 4. National Experimental Teaching Demonstration Center for Food Science and Engineering（ Shanghai Ocean University ） , Shanghai 201306, China; 5. Shanghai Engineering Research Center of Aquatic Product Processing ＆ Preservation, Shanghai 201306, China; 6. Nantong Square Cold Chain Equipment Company, Nantong, Jiangsu 226371, China)

机构地区：[1]上海海洋大学食品学院,上海201306 [2]农业部冷库及制冷设备质量监督检验测试中心,上海201306 [3]上海冷链装备性能与节能评价专业技术服务平台,上海201306 [4]食品科学与工程国家级实验教学示范中心(上海海洋大学),上海201306 [5]上海水产品加工及贮藏工程技术研究中心,上海201306 [6]南通四方冷链装备股份有限公司,江苏南通226371

出　　处：《食品与机械》2017年第12期80-85,90,共7页Food and Machinery

基　　金：国家"十三五"重点研发项目(编号:2016YFD0400303);上海海洋大学科技发展专项基金(编号:A2-0203-17-100207);上海海洋大学博士科研启动基金(编号:A2-0203-17-100317);上海市科委平台能力提升项目(编号:16DZ2280300);上海市科委公共服务平台建设项目(编号:17DZ2293400)

摘　　要：以速冻机中V型条缝喷嘴与平直条缝孔板为研究对象,探索了两种喷嘴结构在相同送风条件下,改变喷嘴与钢带表面间距H对速冻机内部冻结区域流场与压力场的影响,以及钢带表面的换热特征。结果表明:与平直条缝孔板相比V型条缝喷嘴沿横流方向流体流动阻力更小,当钢带与条缝出口间距H与条缝宽度S之比即Hs较小时,横流方向压力极差明显小于平直条缝孔板,此时V型条缝喷嘴出口流速均匀性高于平直条缝孔板;平直条缝孔板横流方向气流流速较大,冻品易被吹飞,不利于冻品安全有效的加工;沿横流方向,平直条缝孔板的钢带表面Nu数存在较大差异性,其平均Nu数较低,而V型条缝喷嘴的差异性较小,平均Nu数高于平直条缝孔板,因此,使用V型条缝喷嘴在钢带表面的换热均匀性更强,且换热均匀性优于平直条缝孔板。In this study, V type slit nozzle and slraight seam hole plate in a quick freezer was used to invedgatethe effect by the change of distance （H） between the nozzle and the plalc surface on the internal flow field and tire pressure field in a freezer with tbesc two kinds of nozzle structures under the same air condition. Moreover, the metal surface heat transfer characteristics were also sludied. The results showed thai the flow resistance of the straight slot seam orifice was smaller than that of the V type slot nozzle along the cross flow direction. The pressure range ahmg cross flow ctirecdon of the V slot nozzle was significantly leas lhan that of the flat nnzzle, when the jet-to plate spacing Its （Hs = H/s） wets at the small wdue, and the V slot nozzle outlet velocity uniformily was higher than tbat of straight slotted orifice. The velocity along cross flow direction in flat nozzle was higher than that of the V slot nozzle, which was not good to safe and effective production for an air impact freezer. Compared with the flat nozzle quick freezer, the difference of the Nu number on the surface of the steel strip of the V slot nozzle wets obviously smaller, and the average Nu numher of the V slot nozzle was greater than that of the flat nozzle. The overall flow and heat transfer characteris tics of the V slot nozzle was better than those of flat nozzle, and the heat transfer uniformity of metal surface of the V slot nozzle was also better than that of flat nozzle.

关 键 词：速冻机 V型条缝喷嘴 平直条缝孔板 横流效应 

分 类 号：TS203[轻工技术与工程—食品科学]