山东大学：《工程热力学》课程PPT教学课件（双语）第一章 Introduction and Basic Concepts

Thermodynamics-An Engineering Approach工程热力学

Thermodynamics-An Engineering Approach 工程热力学 1

能量Energy烩熵EnthalpyEntropy火用Exergy火无Anergy火积Entransy

Energy Enthalpy Entropy Exergy Anergy Entransy 2 能量焓熵 火用 火无 火积

物理量G的中文名称由来炳的由来1923年普朗克到南京讲entropy，物理学家胡复教授任翻泽，由于它概念太复杂，就想了个简单的办法，根据dS=SQ/T，认为S是热量与温度之商，而且与火“滴”有关，从而构成新字名称的由来：G是热清华大学过增元院士提出的。根据G=Q.T/2,炳量与温度之乘积，而且与热有关，从而构成新字摘自清华大学过增元院士的2015.9.24学术报告幻灯片

物理量G的中文名称由来 熵 的由来 1923年普朗克到南京讲 entropy,物理学家胡剛复教授任 翻泽，由于它概念太复杂，就想了个简单的办法,根 据 dS=δQ/T，认为S 是热量与温度之商，而且与火 有关，从而构成新字 “熵” 名称的由来: 清华大学过增元院士提出的。根据 G = QvT/2, G 是热 量与温度之乘积，而且与热有关，从而构成新字 ◎ ◎ 摘自清华大学过增元院士的2015.9.24学术报告幻灯片

物理量G的英文名称由来克劳修斯（1865)创造entropy(炳）的由来因为它与能量相关，所以用字头en，又因它代表热功转换能力，则用希腊字转变的tropy作字段，所以构成新字en-tropy福(积entransy (的由来因为它是与能量相关，所以用字头en，又因它代表热量传递能力，则用具有传递含义的字段transy，所以构成新字en-transy摘自清华大学过增元院士的2015.9.24学术报告幻灯片

克劳修斯(1865)创造 entropy(熵)的由来 因为它与能量相关，所以用字头 en,又因它代表 热功转換能力，则用希腊字转变的 tropy 作字 段, 所以构成新字 en-tropy entransy ( )的由来 因为它是与能量相关，所以用字头 en,又因它 代表热量传递能力，则用具有传递含义的字段 transy, 所以构成新字 en-transy ◎ ◎ 物理量G的英文名称由来 摘自清华大学过增元院士的2015.9.24学术报告幻灯片

HeatEngine，热机制冷机Refrigerator,热泵Heat Pump

Heat Engine, 热机 Refrigerator，制冷机 Heat Pump，热泵 5

Heat Engine(热机): the devices converting heat to workcanbe characterized as- Receive heat (Qμ) from a high temperature source (solar energy,furnace)- Convert part of these heat to work (W) (usually rotating shaft)-Reject theremaining waste heat (Q,)to a low-temperaturesink(theatmosphere,rivers,etc.)-Operateona cycle.- Usually involves a fluid, called working fluid(工质),E.GInternalcombustionengine（内燃机：汽油机和柴油机等）ExternalcombustionEngine（蒸汽发电厂系统等）

• Heat Engine(热机)：the devices converting heat to work, can be characterized as – Receive heat (QH) from a high temperature source (solar energy, furnace) – Convert part of these heat to work (W) (usually rotating shaft) – Reject the remaining waste heat (QL ) to a low-temperature sink (the atmosphere, rivers, etc.) – Operate on a cycle. – Usually involves a fluid, called working fluid(工质). E.G Internal combustion engine（内燃机：汽油机和柴油机等） External combustion Engine（蒸汽发电厂系统等） 6

ThermalEfficiency(热机效率）：等于做功W除以吸收热量QConservation of EnergyPrinciple(能量守恒定律）吸收热量Q.=做功W+放出热量Q热机最高效率?？：20??=1Nth, rev =W/Qμ=1-100Q

• Thermal Efficiency(热机效率): 等于做功W除以吸收热量QH。 • Conservation of Energy Principle(能量守恒定律) 吸收热量QH =做功W+放出热量QL • 热机最高效率??： 7 QL QH TL TH η = 1 - th, rev =W/QH=1- 20 100 ??= 1 - 可逆

AuthorsProfessorYunusA.CengelUniversity ofNevada,RenoDr.Michael A. BolesNorth Carolina State University·Turkey（土耳其）turkey（火鸡）烤火鸡，必须具备一定的热力学常识

Authors • Professor Yunus A.Cengel—University of Nevada, Reno • Dr. Michael A. Boles— North Carolina State University 8 •Turkey（土耳其） turkey（火鸡） 烤火鸡，必须具备一定的热力学常识

Thermodynamics is not an easy subject. Thermodynamics is a funny subject.- The first time you go through it: you don't understandit at all; The second time you go through it, you think youunderstand it, except for one or two points;- The third time you go through it, you know you don'tunderstand it, but by that time you are so used to thesubject, it doesn't bother you anymore.---ArnoldSommerfeld

Thermodynamics is not an easy subject • Thermodynamics is a funny subject. – The first time you go through it: you don’t understand it at all; – The second time you go through it, you think you understand it, except for one or two points; – The third time you go through it, you know you don’t understand it, but by that time you are so used to the subject, it doesn’t bother you anymore. – -Arnold Sommerfeld

Thermodynamics ? ?FromGreekwords:Therme→heat →热thermo(-)dynamics热力学Dynamispower→动力热情激情热力学努力科学教学学习

Thermodynamics ？？ 热 力 学 From Greek words: Therme→heat →热 thermo(-)dynamics Dynamis→power →动力 热力学 热情 激情 努力 科学 教学 学习