刘中良-北京工业大学-高等工程热力学-第2讲

1、by Professor Liu Zhongliang2by Professor Liu Zhongliang3by Professor Liu Zhongliang4by Professor Liu Zhongliang5by Professor Liu Zhongliang6mgzmcUEEUEpk221gzcueeuepk221by Professor Liu Zhongliang7by Professor Liu Zhongliang8 0dE2121DCdEdE12CDby Professor Liu Zhongliang9by Professor Liu Zhongliang10b

2、y Professor Liu Zhongliang11)(12WEEQby Professor Liu Zhongliang12by Professor Liu Zhongliang13Fi 广义力，强度量广义力，强度量xi 广义位移，广延量广义位移，广延量iidxFW by Professor Liu Zhongliang14by Professor Liu Zhongliang15WpdVWby Professor Liu Zhongliang16by Professor Liu Zhongliang17by Professor Liu Zhongliang18WQ0)(WQby Pro

3、fessor Liu Zhongliang19dEWQby Professor Liu Zhongliang20WdEQby Professor Liu Zhongliang21by Professor Liu Zhongliang22WpdVWWdEQWpdVdEQby Professor Liu Zhongliang23pVUHmgzmcHpVEH2021)(0pVddEdH)(0pVddHdEVdppdVdHdE0by Professor Liu Zhongliang24WpdVdEQWVdpdHQ0by Professor Liu Zhongliang25WVdpdHQWpdVdUQb

4、y Professor Liu Zhongliang26Q0 ,iihm 0 ,eehm sWby Professor Liu Zhongliang27l单位时间内，CV储存能的变化可以表示成， J/kg CV, into stream theofenthalpy totalkg/s CV, into flowrate mass 0iihm J/kg CV, ofout stream theofenthalpy totalkg/s CV, ofout flowrate mass 0eehm Wunit time,per CV fromoutput shaft work Wunit time,p

5、er CV intofer heat trans sWQddECVby Professor Liu Zhongliang28SiieeCVWmhmhddEQ00gzchh2021（1 1）多个物流怎么办？）多个物流怎么办？（2 2）如何导出稳定流动）如何导出稳定流动能能 量方程？量方程？by Professor Liu Zhongliang29by Professor Liu Zhongliang30by Professor Liu Zhongliang310em 0SW0Q0c0z00iiCVmhddE00ddmhddEiiCVSiieeCVWmhmhddEQ00by Professor L

6、iu Zhongliang3200iiCVdmhdE0001 ,iiCVCVmmiiEECVdmhdEconstTchhipii0iipiiCVCVmTcmhEE01 ,by Professor Liu Zhongliang33gases) ideal(for CVvCVTmcEiipCVvCVvmTcTmcTmc11 ,iipCVvvCVCVmTcTTmcTcmm)()(11 ,1 ,11 ,1 , ,mmmmmCViCVCVkccvpby Professor Liu Zhongliang34所以iiimkTTTmTm)(11从中解得，(a) 1111TkTTTmmmmmiCVi按理想气体方

7、程，RTmpVRTmVpCV111by Professor Liu Zhongliang35TTppmmCV111TkTTTTTppi1111by Professor Liu Zhongliang36(b) 111111TTkppTTkTTii显然，该式。依据充气参数的不同，可能会出现三种情况：by Professor Liu Zhongliang371111111TTkppTTkTTii11111TTkppTTkiiby Professor Liu Zhongliang38(c) 11111TTkppTTkii11pp011TTkiby Professor Liu Zhongliang39(

8、d) 1TkTiby Professor Liu Zhongliang40(e) 1TkTi(f) 1TkTiby Professor Liu Zhongliang410.51.01.52.0kTi/T10.51.01.52.0T/ T10.50.250.1250pp /1by Professor Liu Zhongliang42(a) 1111TkTTTmmmmmiCVi(b) 111111TTkppTTkTTiiby Professor Liu Zhongliang43(g) 111111ppkTTmmmmmiCViby Professor Liu Zhongliang44ddmhddEd

9、QiiCV0SiieeCVWmhmhddEQ00iiCVdmhdEQ0by Professor Liu Zhongliang45ipiCVvCVTchdmTcdE01 iipCVvdmTcdmTcQ1iCVmiipmmCVvQdmTcdmTcQ0101iipCVvmTcmmTcQ)(11iCVmmm1by Professor Liu Zhongliang46)(1111mmTTkTcQCViv)(111ppRTVmmCV1111TTkkppVQi注意依据充气条注意依据充气条件的不同，件的不同，Q可可以大于零，也可以大于零，也可以小于零！以小于零！by Professor Liu Zhongli

10、ang47by Professor Liu Zhongliang48by Professor Liu Zhongliang49PMM2QWQEnvironmentby Professor Liu Zhongliang50United States Patent and Trademark Office ，USPTO Johnson, Howard R., US4151431 Permanent Magnet Motor, April 24, 1979 Baker, Daniel, US4074153 Magnetic propulsion device, February 14, 1978 H

11、artman; Emil T., US4215330 Permanent magnet propulsion system, December 20, 1977今年埃及科学家的发明热岩CO2发电系统by Professor Liu Zhongliang51by Professor Liu Zhongliang52by Professor Liu Zhongliang53 0TQpvpvby Professor Liu Zhongliang54In the neighborhood (however close) of any equilibrium state of a system of a

12、ny number of thermodynamic coordinates, there exist states that cannot be reached (are inaccessible) by reversible adiabatic processes.by Professor Liu Zhongliang55by Professor Liu Zhongliang56by Professor Liu Zhongliang57热力学热力学吉布斯惯性原理稳定平衡定律第一定律第二定律状态公理第第0定律定律第三定律第三定律量子力学量子力学Schrodinger方程by Professo

13、r Liu Zhongliang58lA system having specified allowed states and an upper bound in volume can reach from any given state one and only one stable state and leave no net effect on its environmentby Professor Liu Zhongliang59by Professor Liu Zhongliang60A basic understandingNo further proving needed by

14、Professor Liu Zhongliang61可逆TQdS0孤立dSIsolated system是与外界既无能量交换，也无物质交换的系统by Professor Liu Zhongliang62 任意系统它的环境孤立系统环境 于是，孤立环境系统 dSdSdS0环境系统dSdSby Professor Liu Zhongliang630环境系统dSdSby Professor Liu Zhongliang640环境系统dSdSby Professor Liu Zhongliang65by Professor Liu Zhongliang66by Professor Liu Zhongli

15、ang67by Professor Liu Zhongliang68Clausius热寂说热寂说by Professor Liu Zhongliang69爱丁顿爱丁顿by Professor Liu Zhongliang70 by Professor Liu Zhongliang71对热寂说的批判对热寂说的批判by Professor Liu Zhongliang72恩格斯的伟大之处恩格斯的伟大之处by Professor Liu Zhongliang73熵方程（熵方程（Entropy Equation）按Clausius等式不等式,TQdS或者写成等式：TQdSdSgproductionen

16、tropy 熵产，TQdSdSgflowentropy 熵流，TQdSfby Professor Liu Zhongliang74熵方程熵方程fgdSdSdSfgdSdSdSby Professor Liu Zhongliang75开口系统的熵方程开口系统的熵方程l不难理解，对于开口系统：l对于单位时间：ddSddSTQmsmsCVgiieeiiiiiieeCVgTQmsmsddSddSby Professor Liu Zhongliang76开口系统的熵方程开口系统的熵方程 K)J/(kg CV, into stream theofentropy kg/s CV, into flowrate

17、 mass iismK) W/(kgunit time,per CV of changeentropy K) W/(kgrate, productionentropy ddSddSCVg K)J/(kg CV, ofout stream theofentropy kg/s CV, ofout flowrate mass eesmK) W/(kg, CV into rate flowentropy iiTQby Professor Liu Zhongliang77熵产与熵增原理熵产与熵增原理l对于孤立系统孤立孤立)()(fgdSdSdS孤立)(gdS0可以简单地表述为： ，即：0 0ddSdSg

18、gby Professor Liu Zhongliang78熵产与熵增原理熵产与熵增原理by Professor Liu Zhongliang80能质能质by Professor Liu Zhongliang81能质能质lQ1000kJ：来自1000K的热源lQ1000kJ：来自500K的热源l环境：300KTCT0QWTTQW0max1热源热源500K 400kJ1000K kJ700maxWby Professor Liu Zhongliang82能质系数能质系数TT01300840138019202460300000.20.40.60.81Tby Professor Liu Zhongl

19、iang83lExergy： 在，能量中能够转变为有用功的那部分能量lAnergy： 不能转变为有用功的那部分能量by Professor Liu Zhongliang84Exergyby Professor Liu Zhongliang85Calculation of Exergy 设系统从温度为T的热源吸热q，环境温度为T0，那么，按定义：anergy exergy 100,qTTexqbTTqwexqqrecqby Professor Liu Zhongliang86闭口系统工质的闭口系统工质的exergy 0环境系统dSdSby Professor Liu Zhongliang87闭口系统工质的闭口系统工质的exergy即 ds+ds0=0， 或 ds0=-ds按可逆过程熵的计算式：00TqdsdsTdsTq000dvpdudsTdexdexdvpdudsT0000)0(00)(dvpdudsTexby Professor Liu Zhong