螺旋槽干气密封的热量平衡膜厚研究.pdf

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1、2015年4月润滑与密封Apr．2015第40卷第4期LUBRICATIONENGINEERINGVo1．40No．4DOI：10．3969／j．issn．0254—0150．2015．004．002螺旋槽干气密封的热量平衡膜厚研究产文宋鹏云．(昆明理工大学化学工程学院云南昆明650500)摘要：干气密封在运转过程中，端面气膜因黏性剪切会产生一定的热量，气体从密封进口到出口因膨胀会吸收一定的热量。定量计算剪切热量和膨胀热量及研究其平衡关系，对干气密封的设计和操作非常重要。针对空气润滑的螺旋槽干气密封，基于间隙等体积的思想，利用当量间隙来等效密封槽台区的槽区和台区间隙，以

2、及利用考虑绝热指数的端面气膜压力控制方程，分别获得剪切热量和膨胀热量的计算式；利用最小二乘拟合法分别获得剪切热量和膨胀热量随气膜厚度变化的表达式，并求得热量平衡膜厚。分别研究转速、槽深、槽宽坝宽比和热量传递系数对热量平衡膜厚的影响规律。结果表明，热量平衡膜厚随转速、热量传递系数的增加而逐渐增加；随槽深、槽宽坝宽比的增加而逐渐减小。关键词：干气密封；螺旋槽；剪切热量；膨胀热量；热效应中图分类号：TH136文献标志码：A文章编号：0254-0150(2015)4-005-4ResearchonHeatEquilibriumFilmThicknessofSpiralGroov

3、eDryGasSealchanWenSongPengyun(FacultyofChemicalEngineering，KunmingUniversityofScienceandTechnology，KunmingYunnan650500，China)Abstract：Duringtheoperationofdrygasseal，someheat(frictionalheat)willbegeneratedbyviscousshearintheendfacegasfilm，andthegaswillabsorbsomeheat(expansionheat)duetoexp

4、ansionwhenthegasflowsfromtheinletintotheoutlet．Itisveryimportanceforthedesignandoperationofthedrygassealtocalculationthefrictionalheatandex—pansionheatquantitativelyandresearchtheheatequilibrium．Fortheairlubricatedspiralgroovedrygasseal，thecalcula—tionformulaofthefrictionalheatwasobtaine

5、dbysubstitutingequivalentclearancefortheclearancesofgrooveandlandbasedontheconceptofequalvolumeoftheclearance，andthecalculationformulaoftheexpansionheatwasobtainedbysolvingthegoverningequationsoffilmpressuremodifiedbyadiabaticexponent．Theexpressionsoffrictionalheatandex—pansionheatvaryin

6、gwiththefilmthicknesswereobtainedbyusingleastsquarefittingmethod，respectively．Thefilmthicknessofheatequilibriumwasgotbysolvingtheheatequilibriumequations．Thevariationofthefilmthicknessofheatequilibriumalongwithrotatingspeed，groovedepth，thewidthratioofgrooveanddamandheattransfercoeficient

7、wasin·vestigated．Theresultsshowthatthefilmthicknessofheatequilibriumisincreasedgraduallywiththeincreasingofrotatingspeedandheattransfercoeficient，anddecreasedgraduallywiththeincreasingofgroovedepthandthewidthratioofgrooveanddam．Keywords：drygasseal；spiralgroove；frictionalh