工程热力学与传热学热工学课后习题答案

第三章作业参考答案习题3-2T`=476℃习题3-3当计算精度要求不高，或气体处于较低温度范围，常采用定值比热，忽略比热与温度的关系。不同气体在标准状态下均为22.4m3，不同气体只要其原子数相同则其摩尔定值比热相等。理想气体定值比热及比热比单原子双原子多原子摩尔定容比热CokJ/(kmol﹒K)摩尔定压比热CpkJ/(kmol﹒K)比热比k1.671.41.29习题3-5（1）可逆绝热过程（2）自由膨胀习题3-6习题3-3320.022Vm2211lnlnpTpscRTp2468.3KT904.010ln8ln)/ln()/ln(1221vvppn54.1570.718kJ/(kgK)28.97vc1.4k121tkRWmTTk11057.62kJtW12svWUmumcTT,0sQUWQsWU121.2svvWUmcTmcTT23mR25mR27mR25mR27mR29mR1.33pvckc2270.48KT121746.3kJsvWUmumcTT0S0,0QU21340KTT0sW2211lnln5.76kJ/KvTvSmcmRTv0.217kJ/(kgK)skJ16.8)(12TTmcUvkJ71.33UQWnkJ47.30nWWt11212141)(1)(TnknmcTTnknmcTTmcQvvnnK2.451T第四章作业参考答案习题4-2（1）输出相同的功t=360℃（2）热效率相等t=260.96℃习题4-3定容过程定温压缩过程习题4-4（1）高温热源熵变低温热源熵变工质熵变孤立系的总熵变（2）高温热源熵变低温热源熵变工质熵变孤立系的总熵变211AAAAAATWQQT211BBBBAABTWQQWT221111ABABABTTTTK1008,52.22212211TTpTpTp54.1570.717kJ/(kgK)28.97vckJ9.435)(121TTmcQvkJ4.264ln2112VVmRTQ%3.39121QQQkJ5.17121QQW%3.60121TTtkJ400011121QTTQWtkJ/K33.3111TQSkJ/K33.3)1(21222TQTQS00S0021SSSSkJ413511121QTTQWtkJ/K33.3111TQSkJ/K33.3)1(21222TQTQS00S0021SSSS