用水冷却苯列管式换热器课程设计

距为32mm,去折流挡板间距为0.3m,壳程的流动截面积按РAO=hD1-dot=0.3×0.9×1-0.0250.032=0.0591m2Рuo=moAoρ水=0.586m/sР壳程当量直径Рde=4(32×0.0322×π4×0.0252)π×0.025=0.0202mРReO=0.0202×0.586×995.70.0008007=14709Р折流板数NB=Lh-1=14Р正三角形排列,取F=0.5Р又由λo=5.0Reo-0.228=0.56Р代入Р得=19373PaР代入Р得=6776PaР=19373+6776×1.15×1=30.07KPaР有上述计算可得壳程和管程压降均小于50KPa,符合设计要求Р4热量核算Р4.1管程对流传热系数Р因Rei=21867>10000,管内对流传热系数由αi=0.023λdiRei0.8Pr0.3Р其中Pr=5.15Р可得αi=763.46W/m2℃Р4.2壳程对流传热系数Р按式αo=0.36λdeRe0.55Pr1/3(μμw)0.14Р其中Pr=5.4 (μμw)0.14≈1Р可得αo=3786.53W/m2℃Р4.3总传热系数РK=Р式中取壳程和管程的污垢热阻为==0.0002(m2℃/W)Р代入数据得РKo=415.46W/(m2℃)Р4.4裕度Р根据设定的传热系数和算出的传热系数Р可得裕度=415.46-350350=18.7%Р由此可得该换热器型号合适Р5设计一览表Р换热器主要结构尺寸和计算结果Р参数Р管程Р壳程Р流量/(kg/h)Р70320Р124129Р进口温度/℃Р80Р35Р出口温度/℃Р40Р25Р压力/MPaР0.05Р0.15Р物性Р定性温度/℃Р60Р30Р密度/(kg/m3)Р879Р995.7Р定压比热容/[kJ/(kg·℃]Р1.842Р4.174Р黏度/[Pa·s]Р0.41Р0.8007