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1、压缩比（Compressionratio）CompressionratioofengineThecompressionratioisaveryimportantconceptintheengine,thecompressionratiorepresentsthedegreeofcompressionofthegas,itisthevolumeofgasandgasbeforecompressionafterthecompressionratio,thetotalvolumeofthecylinderandcombustionchambervolumeratioasthecompr
2、essionratio.Usuallythecompressionratioofgasolineengineis6-10,thecompressionofdieselengineisrelativelyhigh,generally16-22..Whatisthecompressionratiooftheengine?Nomatterthecarontheoptionalpetrolengineanddieselenginecankeepstableandappropriatecompressionratiocanbesmoothandstableoperationoftheeng
3、ine.ThecompressionratioisdefinedasthedegreeofcompressionoftheenginemixtureTheratiobetweenthetotalcylindervolumeandthecompressedcylindervolume(i.e.thevolumeofcombustionchamber).Atpresent,mostofthecarswithreciprocatingengines'absolute',simplyspeaking,isintheenginecylinder,apistoncycletodostraig
4、htreciprocatingmotionandhasendlesscycle,sointhiscycleandcontinuingworktriphasitsmotionrange.Theengineisacylinder,whenthepistonisatitslowestpoint,pointatthistimeiscalledtheendingpointofthecylinder,includingvolumeformedbythecombustionchamberismaximumwhenthepistonstrokevolume,reversemovement,tor
5、eachthehighestpointposition,thispositioniscalledTDC,volumefortheformationofthewholepistonstrokevolumeminimum,requiredtocalculatethecompressionratioisthemaximumstrokevolumeandminimumvolume.EdittherelationshipbetweencompressionratioandengineperformanceThecompressionratiohasgreatrelationshipwith
6、theperformanceoftheengine,weallknowthatthegasolineengineinoperation,bringinginisusuallythemixtureofgasolineandairmixedintothepistoninthecompressionprocessintheuplink,inadditiontovolumeextrusionmixturereduced,thereweretwokindsofvortexflowandturbulentflowphenomenon.Whenthegasintheclosedvesselis
7、compressed,thepressureincreaseswiththeincreaseoftemperature.Iftheenginecompressionisrelativelyhigh,relativelyhighercylinderpressureandtemperaturegeneratedduringcompression,gasolinemoleculesinthemixedgascanbevaporizedmorecompletely,morefinepar
