欢迎来到天天文库
浏览记录
ID:57652323
大小:957.50 KB
页数:7页
时间:2020-08-30
《流体力学与传热英文习题(64学时).doc》由会员上传分享,免费在线阅读,更多相关内容在教育资源-天天文库。
1、ProblemsofFluidFlowandHeatTransferforUnitOperationsofChemicalEngineeringZHONGLi(CollegeofChemistryandChemicalEngineering,SouthChinaUniversityofTechnology)1.Waterispumpedataconstantvelocity1m/sfromlargereservoirrestingonthefloortotheopentopofanabsorptiontower.Thepointofd
2、ischargeis4meterabovethefloor,andthefrictionlossesfromthereservoirtothetoweramountto30J/kg.Atwhatheightinthereservoirmustthewaterlevelbekeptifthepumpcandeveloponly60J/kg?2.Thefluid(density1200kg/m3)ispumpedataconstantrate20m3/hfromthelargereservoirtotheevaporator.Thepre
3、ssureabovethereservoirmaintainsatmospherepressureandthepressureoftheevaporatorkeeps200mmHg(vacuum).Thedistancebetweenthelevelofliquidinthereservoirandtheexitofevaporatoris15meterandfrictionallossinthepipeis120J/kgnotincludingtheexitofevaporator,whatisthepumpeffectivewor
4、kandpowerifthediameterofpipeis60mm?3.Watercomesoutofthepipe(Φ108x4mm),asshowninFig.Thefrictionlossofthepipelinewhichdoesnotcoverthelossattheexitofpipecanbecalculatedbythefollowingequation:hf=6.5U2whereUisthevelocityinthepipe,finda.watervelocityatsectionA-A'.b.waterflowr
5、ate,inm3/h.4.Waterpassesthroughthevariablepipe.Thevelocityinthesmallpipeis2.5m/s.TheverticalglasstubesareinsertedrespectivelyatthesectionAandBtomeasurethepressure(seefig.)Ifthefrictionlossbetweentwosectionis15J/kg,whatisthewatercolumndifferencebetweentwoglasstubes?Bythe
6、way,drawtherelativeliquidcolumnheightoftwotubesintheFig.5.Acentrifugalpumptakesbrine(density1180kg/m3,viscosity1.2cp)fromthebottomofasupplytankanddeliversitintoanothertank.Thelinebetweenthetanksis300mof25mmdiameterpipe(innerdiameter).Theflowrateis2m3/h.Inthisline,therea
7、retwogatevalves,fourelbows(90o)andonereturnbend,whatisthefrictionlossiftheroughnessofpipeis0.025mm?6.Theorificemeter(diameteroforifice0.0001m)isinstalledformeasuringtheflowrate.TheindicatingliquidoforificeismercuryifUshapepressuregaugereadingis0.6meterandorificecoeffici
8、entcanbetakenas0.61,whatistheflowrateofwater?7.Waterflowsthroughapipewithadiameterdi100mmasshowninfigure.a.whe
此文档下载收益归作者所有