习题(传热).pptVIP免费

返回3223212'12121127(49):60,393120,2205/,,57,50,7200/,810/,2.2/,510,30,80:(1)(2)(3),,,;4sspsssPLmTKCrkJkgKmmdmmmkghkgmCkJkgCPastCtCmKmttTd211解题指南已知=12000W/m内管d求不变''212221112122211237,40,?:(1)()220572002.2(8030)359/0.0997/8030(2)61.7,()12030lnln1208072002.210(8030)0.0573600sspssmspmmmdmmLmrmCttmmkghkgstttCmCttKAtTtTtK解26061.7332/()KWmC以内管外表面计返回2442230.80.40.80.42222221.82222''1.81.822122127200/36000.050.7850.05(3)Re1.0210>1051010.023()0.023(),0.7850.041()()1.494,0.05srrdudGdudmPPdddddddd原工况1原工况:K22222'222''21''1222122211210.057120000.05110.057389/;332120000.051.4941.494389581/110.047475/()120005810.040(),,lnspmWmCWmCdKWmCdttQmCttKAQtTtTt'1以内管外表面计K不变不变''''''111''1,3320.0576050.84750.047KdLKAKAKdLKdLLmKd返回2212''2s22112221221122128(411):60,25,20,90,20,401:?(2),=m,QQ2:(1)()lnln34996:3600sssspspPnmmdmmTCVtCtCKmttTtmCttKAmCKdLnTtTtTt31解题指南已知dL=1.3m,=34m/h,求(1)将单管程改为四管程是否解即32222135's2''2''s22s2s2's2s22290204.1710ln0.0251.3602154/()9040(2)()349964.1710(4020)7.845103600m/mn0.7851u:m=m==m/2umnn0.785spKKWmCQmCttWndd以外表面计单管程改为四管程:原冷凝负荷现工况12222114221\,ddKKdd管壁污垢热阻及蒸汽冷凝热阻均可忽略不计返回'''0.80.40.80.822222'2'''''2212122121'12'23'20.023()Pr,()21.7411.74121543750/()()ln22ln349969020()4.1710ln372360090ssppduKudKuKWmCmttmTtQCttKACKdLnTtTtTtt以外表面计'2''32221'5'500.0251.36068.334996()4.1710(68.320)2236009.4710>,,.sptCmQCttQWQQ管程由单管程改为四管...