1、1 Thermodynamic fundamentals of refrigeration and cryogenic engineering1.1 Methods of refrigeration1.1.1 Refrigeration by phase change第一章 制冷与低温的热力学基础第一节 制冷的方法一、相变制冷2/28/20232William Cullen and his student Joseph Black(1755,English)IceEtherVacuum pumpEtherVacuum pump2/28/20233Refrigeration by phase c
2、hange 相变制冷MeltingSublimatingPhase changePressure dropNormal Boiling PointCritical PointTb（K）tb（）Tc（K）tc（）C2H6O351.578.3516.2243.0Ether307.834.6467.2194SO2263.2-10430.7157.5NH3239.9-33.3406.2133.0CO2194.8-78.4304.331.1C2H4169.5-103.7282.59.3CH4111.7-161.5190.5-82.7O290.3-182.9154.8-118.4N274.4-198.81
3、26.3-146.9H220.4-252.833.3-239.9He4.3-268.95.3-267.92/28/20234TaTTcTbTf1atmRefrigeration by phase change 相变制冷Melting Vaporizingdukinetic=du -dupotential 0Pressure dropPhase changedu=(hg-u)dm/m (hg-hl)dm/m =dm/m 0The first law:Q=dU+W+(h+c2/2+gz)dmout -(h+c2/2+gz)dminSince:(hdm)out=hgdmThus:-hgdmout=h
4、gdm=dU=d(mu)=mdu+udm mdu=(hg-u)dm2/28/20235TaTTcTbTf1atmVaporizingRefrigeration by phase change and pressure drop相变制冷 EvaporatingSublimatingMelting2/28/20236TaTaTaTaTf1atmNormal boiling point and saturated passure 标准沸点和饱和压力Normal Boiling PointCritical PointTb（K）tb（）Tc（K）tc（）C2H6O351.578.3516.2243.0E
5、ther307.834.6467.2194SO2263.2-10430.7157.5NH3239.9-33.3406.2133.0CO2194.8-78.4304.331.1C2H4169.5-103.7282.59.3CH4111.7-161.5190.5-82.7O290.3-182.9154.8-118.4N274.4-198.8126.3-146.9H220.4-252.833.3-239.9He4.3-268.95.3-267.9EtherO2、N2 H2、HeNH3CO22/28/20237TaTTcTbTf1atmM.Van Marum(1787,Holland)Liquefyi
6、ngNH3p1/p2=V2/V1Boyles lawBoyles law波意尔波意尔-马略特定律马略特定律NH3RefrigeratingCooling2/28/20238TaTaTaTaTf1atmliquefaction by pressurization and phase change by underpressure 加压液化和降压相变Normal Boiling PointCritical PointTb（K）tb（）Tc（K）tc（）C2H6O351.578.3516.2243.0Ether307.834.6467.2194SO2263.2-10430.7157.5NH3239.
7、9-33.3406.2133.0CO2194.8-78.4304.331.1C2H4169.5-103.7282.59.3CH4111.7-161.5190.5-82.7O290.3-182.9154.8-118.4N274.4-198.8126.3-146.9H220.4-252.833.3-239.9He4.3-268.95.3-267.9EtherO2、N2 H2、HeNH3CO22/28/20239Cascade systems and Permanent gases复叠式系统和永久气体Normal Boiling PointCritical PointTb（K）tb（）Tc（K）tc
8、（）C2H6O351.578.3516.2243.0Ether307.834.6467.2194SO2263.2-10430.7157.5NH3239.9-33.3406.2133.0CO2194.8-78.4304.331.1C2H4169.5-103.7282.59.3CH4111.7-161.5190.5-82.7O290.3-182.9154.8-118.4N274.4-198.8126.3-146.9H220.4-252.833.3-239.9He4.3-268.95.3-267.9TaTaTaTaTf1atmEtherO2、N2 H2、HeNH3CO2C2H4NH32000 atm
9、2/28/202310C.C.de La Tour(1821,French),M.Faraday(1823,English)and critical pointsAlcohol 119atmGlass ball Liquid chlorineChloride CrystalsCoolingCooling2/28/202311C.C.de La Tour(1821,French),M.Faraday(1823,English)and critical pointsTaTf1atmTTcTbVaporizingAlcohol 119atmGlass ball 63atm,243Van der Wa
10、als(1873,Holland)论气态和液态的连续性论气态和液态的连续性Liquid chlorineChloride CrystalsCoolingTaTTcTbTf1atm2/28/202312Guillaume Amontons(1663-1705,French)and the absolute zeroAmontons Law:p1/p2=T1/T2查理定律查理定律zeroTp0 p1/T1=(p1-p2)/(T1-T2)=p/TzerozeroTpppp0010000100(p100 1.417p0)Tzero=-240 1.1 Methods of refrigeration1.1.1 Refrigeration by phase change1.1.2 Refrigeration by gas expansion1.1.2.1 Refrigeration by gas release第一节 制冷的方法一、相变制冷二、气体膨胀制冷
