1、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1.绝热放气制冷2/28/20232Cascade systems and Permanent gases复叠式系统和永久气体Normal Boiling PointCritical PointTb（K）tb（）Tc（K）tc（）C2H6O351.578.3516.2243.0Eth
2、er307.834.6467.2194SO2263.2-10430.7157.5NH3239.9-33.3406.2133.0CO2194.8-78.4304.331.1C2H4169.5-103.7282.59.3CH4111.7-161.5190.5-82.7O290.3-182.9154.8-118.4N274.4-198.8126.3-146.9H220.4-252.833.3-239.9He4.3-268.95.3-267.9TaTaTaTaTf1atmEtherO2、N2 H2、HeNH3CO2C2H4NH32000 atm2/28/20233L.Galletet(Dec.,187
3、7,French)and liquefaction of oxygenO2 300atmTapSO2-29TaTTcTbTf1atmLiquefying2/28/20234R.Pictet(Dec.,1877,Swiss)and liquefaction of oxygenO2 320atm,-140TapCO2SO2Normal Boiling PointCritical PointTb（K）tb（）Tc（K）tc（）SO2263.2-10430.7157.5CO2194.8-78.4304.331.1O290.3-182.9154.8-118.42/28/20235Z.F.Wroblews
4、ki,K.S.Olszewski (1883,Poland)Oxygen 320atm,-140TapCO2SO2Liquid O2(-130)C2H4O2(320atm)Liquid chlorineChloride CrystalsCooling2/28/20236Z.F.Wroblewski,K.S.Olszewski (1883,Poland)and M.Faraday(1823,English)TaTcTbTf1atmO2Liquid O2(-130)C2H4O2(320atm)ChlorineNormal Boiling PointCritical PointTb（K）tb（）Tc
5、（K）tc（）SO2263.2-10430.7157.5CO2194.8-78.4304.331.1O290.3-182.9154.8-118.4Liquid chlorineChloride CrystalsCooling2/28/202371.1.2.1 Refrigeration by gas releasedukinetic 0p、vTh、udu=(h-u)dm/m=pvdm/m 0The first law:Q=dU+W+(h+c2/2+gz)dmout -(h+c2/2+gz)dmindul=(hg-ul)dm (hg-hl)dm=dm/m 膨胀作功膨胀作功 低压气体排出汽缸低压气
6、体排出汽缸A 压缩过程压缩过程 B 冷却过程冷却过程 C 回热过程回热过程 D 膨胀过程膨胀过程2/28/202311Refrigeration by a work-producing device等熵膨胀制冷u=upotential+ukineticdu=-W/m 0dukinetic 0The first law:Q=dU+WdU=-W 膨胀作功膨胀作功 低压气体排出汽缸低压气体排出汽缸upotential 02/28/202312Differential(integral)isentropic expansion coefficient微分（积分）等熵效应p、vTh、upTvpcTpTs
7、aS21ppsdpaT0pTv0sD 膨胀过程：高压气体进入汽缸膨胀过程：高压气体进入汽缸 膨胀作功膨胀作功 低压气体排出汽缸低压气体排出汽缸微分等熵效应：微分等熵效应：积分等熵效应：积分等熵效应：0T2/28/202313Refrigeration by gas expansion气体膨胀制冷（等熵膨胀和绝热放气制冷）Wmpv绝热放气绝热放气等熵膨胀等熵膨胀2/28/202314TaTaTaTaTf1atmNormal boiling points and critical points标准沸点和临界点Normal Boiling PointCritical PointTb（K）tb（）Tc
8、（K）tc（）C2H6O351.578.3516.2243.0Ether307.834.6467.2194SO2263.2-10430.7157.5NH3239.9-33.3406.2133.0CO2194.8-78.4304.331.1C2H4169.5-103.7282.59.3CH4111.7-161.5190.5-82.7O290.3-182.9154.8-118.4N274.4-198.8126.3-146.9H220.4-252.833.3-239.9He4.3-268.95.3-267.9EtherO2、N2 H2、HeSO2CO21.1 Methods of refrigera
9、tion1.1.1 Refrigeration by phase change1.1.2 Refrigeration by gas expansion1.1.2.1 Refrigeration by gas release1.1.2.2 Refrigeration by a work-producing device1.1.2.3 Refrigeration by Joule-Thomson expansion第一节 制冷的方法一、相变制冷二、气体膨胀制冷1.绝热放气制冷2.等熵膨胀制冷3.节流膨胀制冷2/28/202316Joule-Thomson effect(1852,English)焦
10、耳-汤姆逊效应The first law:q=h+w+c2/2+gzh=0 h1=u1+p1v1h2=u2+p2v2uK p1v1p2v2 uPh1=h22/28/202317Differential(integral)Joule-Thomson coefficient 微分（积分）节流效应hhpTapphcvTvTa微分节流效应：微分节流效应：积分节流效应：积分节流效应：h1=h2uK p1v1p2v2 uP2/28/202318Refrigeration by Joule-Thomson expansion节流膨胀制冷CoolingHeatingIdeal gasReal gashhpTa
11、Inversion curseuK p1v1p2v2 uPTTaTcTbTf1atmExpansionh1=h2微分节流效应：微分节流效应：CoolingHeatingInversion curse2/28/202319Refrigeration by Joule-Thomson expansion节流膨胀制冷2/28/202320Inversion points转化曲线Normal Boiling PointCritical PointInversion PointTb（K）Tb（）Tc（K）Tc（）Tmax（K）tmax（）N274.4-198.8126.3-146.9604331H220
12、.4-252.833.3-239.9204-69He4.3-268.95.3-267.946-227TTaTcTbTf1atmExpansionCoolingHeating2/28/202321J.Perkins(1834,American)EvaporatorEtherCondenserCompressorExpansion valves压缩机压缩机冷凝器冷凝器节流阀节流阀蒸发器蒸发器2/28/202322Linde-Hampson cycle(1895,German-English)Recuperator2/28/202323Inversion points转化曲线Normal Boili
13、ng PointCritical PointInversion PointTb（K）Tb（）Tc（K）Tc（）Tmax（K）tmax（）N274.4-198.8126.3-146.9604331H220.4-252.833.3-239.9204-69He4.3-268.95.3-267.946-227TTaTcTbTf1atmHydrogenExpansion2/28/202324Sir J.Dewar(1898,English)and liquefaction of hydrogen杜瓦和氢的液化Minds are like parachutes.They only function whe
14、n they are open.Normal Boiling PointCritical PointInversion PointTb（K）Tb（）Tc（K）Tc（）Tmax（K）tmax（）N274.4-198.8126.3-146.9604331H220.4-252.833.3-239.9204-69He4.3-268.95.3-267.946-2272/28/202325H.K.Onnes(1908,Holland)and liquefaction of helium氦的液化H2HeH2CH3ClC2H4O2Air2/28/202326Refrigeration by gas expan
15、sion气体膨胀制冷Wmpvpv2/28/202327Refrigeration by expansion of working substances工质膨胀制冷2/28/202328References_ Chapter 11.1.绝对零度的探索绝对零度的探索:低温物理趣谈低温物理趣谈/K.K.门德尔松著门德尔松著;张长贵张长贵,孙大坤孙大坤,秦允豪译秦允豪译.北京北京:科学普及科学普及出版社出版社,1987 1987 2.2.向绝对零度挑战向绝对零度挑战/陈狱生著陈狱生著.北京北京:开明书店开明书店,1951 1951 2/28/202329Homework_22 2、请根据热力学一般关系式推导微、请根据热力学一般关系式推导微分等熵效应和微分节流效应的定义式分等熵效应和微分节流效应的定义式（1-41-4）和（）和（1-181-18）。）。2/28/202330 课程网站 http:/
