H2?Hl,2?(1?x)?Hg,2?x
即有：x?S2?Sl,2?6.7976?1.0912?5.7064?0.8774
Sg,2?Sl,27.5947?1.09126.5035v2?0.8774?3.24?(1?0.8774)?0.0010301?2.8429 m?kg3?1
H2?0.8774?2646.0?(1?0.8774)?340.56?2363.35 kJ?kg?1③ 作图
T 4MPa 1 50kPa 2 S ④ 若过程在封闭体系进行。由热力学第一定律 ?u?q?w
∵q=0
w??u??(h?pv)??h??(pv)∴
?(2363.35?3215.26)?(50?10?2.8429?4?10?0.08269)?10 ??851.91?188.615 ??663.30 kJ?kg?136?3
即：体系从外界获功663.30 kJ·kg
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