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1、HeatTransferLesson22一、教学内容：通过对本单元的学习，掌握热传递的相关基本词汇，了解热传递的几种类型和热传递的基本计算，并掌握热传递相关英语的翻译技巧。二、本章节参考文献：FromEnglishforscienceandtechnologyonchemistryandchemicalengineering,byLiuyuhong,2006单元简介IntroductionBasicConsiderationsIntroductionofheattransferConduction;Convection;Ra
2、diation.IntroductionofheattransferInthemajorityofchemicalprocessheatiseithergivenoutorabsorbed,andinaverywiderangeofchemicalplant,fluidsmustoftenbeeitherheatedorcooled.inthemajorityofchemicalprocessinaverywiderangeofchemicalplant在大多数化学过程中在化工厂的很多工艺中Thusinfurnaces,ev
3、aporators,distillationunits,driers,andreactionvessels，oneofthemajorproblemsisthatoftransferringheatatthedesiredrate.因此，在反应炉、蒸发器、蒸馏装置、干燥器和反应容器中，一个主要问题是以期望的速度传递热。Inasolid,theflowofheatbyconductionistheresultofthetransferofvibrationalenergyfromonemoleculetoanother,and
4、influidsitoccursinadditionasaresultofthetransferofkineticenergy.vibrationalenergykineticenergy振动能动能Thisprocessisparticularlyimportantwithmetalsandaccountsfortheirhighthermalconductivities.句中的their指thermalconductivitiesmetals热导率Inforcedconvection,itisduetoeddycurren
5、tsinafluidinturbulentmotion.forcedconvectioneddycurrentsturbulentmotion强制对流涡流湍动Whenthisradiationfallsonasecondbodyitmaybepartiallyreflected,transmitted,orabsorbed.Itisonlythefractionthatisabsorbedthatappearsasheatinthebody.当这种辐射碰到第二个物体它就可以发生部分的反射，传递或吸收。但只有被吸收的那部分表现
6、为物体中的热。BasicConsiderationsInthemajorityofheatexchangerunits,theprocessiscomplicatedinthattheheathastopassthroughanumberofinterveninglayersbeforeitreachesthematerialwhosetemperatureistoberaisedandtheformoftheequationmaybecomplex.heatexchangerunitsinthatinterveningla
7、yers换热机组因为中间层Theheatfromtheflameistransferredbyacombinationofradiationandconvectiontotheoutersurfaceofthepipes,thenpassesthroughthewallsbyconduction,and,finally,istransferredtotheboilingoilbyconvection.火焰的热量通过辐射和对流转移到管道外表面，然后通过传导穿过管道壁，并最终通过对流被沸腾的油吸收。Afterprolongedu
8、sage,soliddepositsmayformonboththeinnerandouterwallsofthepipes,andthesewillthencontributeadditionalresistancetothetransferofheat.afterprolongedus
