?p?5-21 T2?T1?2??p1?n?1n?0.2??800????1?1.2?11.2?611.8 K
R?T1?T2?0.2968??800?611.8?w???279.3 kJ/kg
n?11.2?1v1?RT10.2968?800??0.237 m3/kg p11000RT20.2968?611.8??0.908 m3/kg p2200T2pp?RT2?Rln2?ln?Rln2T1p1??1T1p1v2??s?cpln ?1.4?0.2968611.80.2ln?0.2968ln?0.20 kJ/kg?K1.4?18000.1
exu1?exu2?u1?u2?p0?v2?v1??T0?s2?s1?R?T1?T2??p0?v2?v1??T0?s??1 0.2968 ???800?611.8??100??0.908?0.237??300?0.21.4?1 ?132.5 kJ/kg ?5-22 m?pV200?1011??13.94 kg RT10.287?500Q?mcp?T2?T1??13.94?1.005??600?500??1400.7 kJ
?s?cplnT2600?1.005?ln?0.1832 kJ/kg?K T1500Exq?Q?T0m??s?1400.7?300?13.94?0.1832?634.6 kJ Anq?T0m??s?300?13.94?0.1832?766.1 kJ
工程热力学 26
5-23 ws??R?T1?T2?1.4?0.287??500?320???180.74 kJ/kg
??11.4?1T2p3200.1?Rln2?1.005?ln?0.287?lnT1p15000.5
?s?cpln ?0.0134 kJ/kg?Kexh1?exh2?h1?h2?T0?s2?s1??cp?T1?T2??T0?s ?1.005??500?320??300?0.0134?184.92 kJ/kg
?ex?ws180.74??97.7%
exh1?exh2184.92T2?300?20?1??67.3% T1?1000?20T0300?1??70% T110005-24 ⑴??1?⑵?t?1?L?Q1??t????1000??0.7?0.673??27 kJ ⑶Q2?Q1?1????1000??1?0.673??327 kJ
?11??11??S?Q1????Q2????T1?T1??T0T2??
1?1??1?1 ?1000???327?????0.09 kJ/K?9801000??300320?L?T0?Siso?300?0.09?27 kJ 符合！
工程热力学 27