工程热力学绪论讲稿.ppt

工程热力学EngineeringThermodynamicsIntroduction(绪论)Thermodynamicscanbedefinedasabranchofscienceofenergy.§0.1Whatdoesthermodynamicsconcerns?(热力学涉及哪些内容?）热电厂(热能→机械能)ThermalPowerPlant(ThermalEnergy→MechanicalEnergy?WhydoweneedtolearnEngineeringThermodynamics?自然能源的种类(Categoriesofnaturalenergyresources)A.化学能（Chemicalenergy）:suchas:煤炭（coal）石油（crudeoil）天然气（naturalgas）沼气（firedamp,etc）.B.机械能（Mechanicalenergy）suchas:风力资源（windresources）水力资源（waterresources）潮汐能（tidalenergy）,etc.C.热能（Thermalenergy）suchas:太阳能（solarenergy）地热能（geothermalenergy）,etc.D.原子能（Nuclearenergy）ChemicalenergyThermalenergy能源转换与利用的关系(Relationshipbetweenenergytransformationandutilization)90%ofenergyresourcesaretransformedintothermalenergybeforeitisused.ThermalenergyMechanicalenergy(1)广泛性universallyHearttheheatingandair-conditioningsystems,therefrigerator,humidifier,thepressurecooker,thewaterheater,theshower,theironandeventhecomputer.automotiveengines,rockets,jetengines,andconventionalandnuclearpowerplans,solarcollectorandthedesignofvehiclesfromordinarycarstoairplanes.Disorganizedenergyorganizedenergy（无序能）（有序能）4.能量转换的一些实例(ExamplesofSomeenergytransformationapplication)火力发电装置基本特点GeneralizedRepresentationofHeatEngines（热机工作原理的示意）HowmanyWcanbeproducedbyabsorbingQH?IsthereanyrelationshipbetweenQH,QLandW?(2)内燃机装置Internalcombustionengine空气、油内燃机装置基本特点冰箱(Refrigerator)(3)制冷空调装置RefrigerationSystemHeatsourceofhightemperature（高温热源hotreservoir）Workingsubstanceorworkingmedium（工作介质）C.Thechangeinstateofworkingmedium（工质的状态变化）D.Heatsinkoflowtemperature（低温冷源coldreservoir）Thermalenergyreservoir:heatsourceheatsink§0.2研究的主要内容MainContentsItassertsthatenergyhasquantityaswellasqualityandactualprocessoccurinthedirectionofdecreasingqualityofenergy.阐明能量不仅有量的属性，而且也有质的属性，过程总是朝着能量贬值的方向进行。Forexample:acupofhotwater2.工质的性质PropertiesofWorkingMedium3.工程应用Someapplications主要内容MainContents(1)宏观方法(ClassicalMethod)连续体(continuum)，用宏观物理量描述其状态，其基本规律是无数经验的总结特点：可靠，普遍，不能任意推广经典（宏观,平衡）热力学classical(macroscopic,equilibrium)thermodynamics从微观粒子的运动及相互作用角度研究热现象及规律。Microscopi