工程热力学第一章 基本概念VIP免费

第一章基本概念CHAPTER1.BASICCONCEPTSCONTENTS1.1ThermodynamicSystem热力系统1.2PropertiesofASystem系统的状态参数1.3StateandEquilibrium状态及平衡状态1.4ProcessandCycles过程与循环www.themegallery.comCompanyLogoTERMINOLOGY(术语）closedsystem闭口系统opensystem开口系统adiabaticsystem绝热系统isolatedsystem孤立系统boundary边界surrounding环境equilibriumstate平衡状态process过程interaction相互作用Turbine汽轮机pistoncylinderdevice活塞-缸装置temperature温度pressure压力absolutepressure绝对压力relativepressure相对压力gagepressure表压力vacuumpressure真空度atmosphericpressure大气压力reciprocal倒数mass质量，物质§1.1热力系统THERMODYNAMICSYSTEM1.System（热力系统）系统就是指被选做研究对象的物体或空间。（Aquantityofmatteroraregioninspacechosenforstudyiscalledasystem.）Forexample:气缸-活塞装置Cylinder-pistondevices汽轮机SteamturbineWorkOutputBoundarySystemHeatAbsorptionWorkingMediumHeatrejectionWorkOutputSystemWorkingMedium(1)Surroundings（外界）Themassorregionoutsidethesystemiscalledsurroundings.(2)Boundary（边界）Therealorimaginarysurfacethatseparatesthesystemfromitssurroundingsiscalledboundary.(3)Interactionsbetweensystemanditssurroundings(系统与外界间的相互作用）Therearemassorenergyexchangebetweensystemanditssurroundings.Andtheymustcrosstheboundaries.系统与外界之间有质量及能量的交换，且都必须穿越边界2.System,SurroundingsandBoundary系统、外界和边界SystemSurroundingsMassexchangeEnergyexchangeMassenteringorleavingthesystemEnergyenteringorleavingthesystemEnergycancrosstheboundary,intheformofheatandwork.(4)CharacteristicsofboundariesBoundariesareselectedsubjectively边界是人为选定的.Boundariescanbefixedormovable.边界可以是固定的，也可以是可移动Boundariescanberealorimaginary.边界可以是真实的，也可以是假想的Boundariesareselectedsubjectively热力系统选取的人为性：锅炉boiler汽轮机(turbine)发电机(generator)给水泵(pump)凝汽器(condenser)过热器(reheater)OnlyworkexchangeOnlyheatexchangeWorkandheatexchange真实、虚构固定、活动fixed、movablereal、imaginary(1)Intermsoftheinteractionbetweensystemanditssurroundings依据系统和外界之间的相互作用YesNoMass?openclosedHeat?non-adiabaticadiabaticWork?withworkwithoutworkMass,heatorwork?non-isolatedisolated3.Typesofsystems热力系统分类Aclosedsystem(acontrolmass控制质量)consistsofafixedamountofmass,andnomasscancrossitsboundary.Thatis,nomassentersorleaveaclosedsystem.闭口系与外界无物质交换suchas,Piston-cylinderdevice(汽缸-活塞装置）Anopensystem(oracontrolvolume控制体积）isaproperlyselectedregioninspace.Bothmassandenergycancrosstheboundaryofacontrolvolume.开口系与外界有物质交换suchas,AWaterheater,aturbineandacompressor,etcA.ClosedsystemandOpensystem闭口系统和开口系统Adiabaticsystemisthatnoheatcrosstheboundaryorheatisnegligiblecomparedwiththeworkcrosstheboundary绝热系统与外界之间无热量交换Isolatedsystemisaspecialcasethatnomassandenergycrosstheboundary.孤立系统与外界之间无任何物质和能量交换B.AdiabaticsystemandIsolatedsystem绝热系统和孤立系统1234mQW1opensystem非孤立系＋相关外界＝孤立系1+2closedsystem1+2+3adiabaticclosedsystem1+2+3+4isolatedsystem（2）Intermsofinternalconditionofthesystem（依据系统的内部状况）其它分类方式PhysicalandChemicalProperties(物理化学性质)EvenSystem均匀系UnevenSystem非均匀系NumberofWorkingmedium工质种类multisubstancesystem多元系Singlesubstancesystem单元系Phase相态MultiplePhase多相SinglePhase单相§1.2STATEANDSTATEPROPERTIES状态及状...