摘要
冲洗是强化机械密封换热的主要措施之一,但在一些特殊场合下冲洗量的大小往往是给定的,因此,需要采取一些强制换热措施来改善机械密封的运行环境。通过在密封环的外周面开设织构,针对冲洗量一定的情况,基于SST k-ω湍流模型,采用Ω方法分析了不同转速下织构深径比对端面温度、外周面局部努塞尔数Nu和织构区域流场的影响,对比研究了动环织构和静环织构的换热机理。研究结果表明:在相同工况、冲洗量和织构几何参数条件下,若动静环外周面单独开设织构,则动环的换热效果更佳。在相同转速下,动环外周面开设织构时,减小深径比会使织构内部换热效果差的区域增大,换热效果减弱,但对于静环织构,减小深径比会使织构流体流动下游侧换热效果差的区域减小,换热效果增强;随着转速的增大,较小深径比动环织构内部出现了新的差换热效果区域,单位面积换热强度显著下降。因此,为获取较优的换热效果,在低转速下宜选取小深径比织构,而在高转速下应选取大深径比织构。
Flushing was one of the main measures for heat transfer enhancement of mechanical seals.But in some special occasions,the flow rate of flushing was given,so some forced heat transfer measures were needed to improve the operating environment of mechanical seals.Through processing texture on the circumference surfaces of the sealing rings and aiming at the condition of a given amount of flushing,the influences of speed and depth to diameter ratio on interface temperature,local Nu on circumference surfaces and flow field in textured regions were analyzed by SST k-ωturbulence model andΩmethod,heat transfer mechanism of texture processed on rotor or stator was compared and analyzed.The results show that under the same working conditions,flow rate of flushing and texture geometric parameters,the heat transfer of rotor is better if the texture is set on the circumference surfaces of rotor and stator separately.Under the same speed,when texture is processed on the circumference surface of rotor,reduction of the aspect ratio may increase the areas with poor heat transfer inside the texture and weakened heat transfer.But when texture is processed on the circumference surfaces of stator,the conclusion is completely opposite.As the speed increases,a new area of poor heat transfer appears in a small aspect ratio rotor texture,the heat transfer intensity per unit area is decreased significantly.Therefore,in order to obtain better heat transfer effectiveness,the small aspect ratio texture may be selected under low speed,and the large aspect ratio texture may be selected under high speed.
作者
余旻丰
彭旭东
孟祥铠
梁杨杨
YU Minfeng;PENG Xudong;MENG Xiangkai;LIANG Yangyang(School of Mechanical Engineering,Zhejiang University of Technology,Hangzhou,310014)
出处
《中国机械工程》
EI
CAS
CSCD
北大核心
2023年第11期1268-1279,共12页
China Mechanical Engineering
基金
浙江省自然科学基金重大项目(LD21E050002)
国家自然科学基金(52175193)
国家重点研发计划(2018YFB2000800)。
关键词
表面织构
外周面
接触式机械密封
强化换热
texture
circumference surface
contact mechanical seal
heat transfer enhancement
