冷凝器计算模板

"冷凝器(tk=40,to=2）换热计算",,,,

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1.,设计参数：Qk=SRF-120压缩机,,W,

,制冷剂：R22,,,

,冷却介质：H2O,,,

,冷凝温度：tk=,40,℃,

,进水温度：t1=,30,℃,

,出水温度：t2=,35,℃,

,水侧污垢系数：γo=,0.000086,m2K/W,

2.,换热管参数：,,,

2.1,换热管管内参数：,,,

,内径：di=,0.01348,m,

2.2,换热管管外参数：,,,

,坯管外径：do=dm=,0.01588,m,

,换热管光管段长度：lz=2×0.05,0.1,m,

,翅片外径：Dw=,0.01588,m,

,翅片根径：Dg=,0.01418,m,

,翅片高：h=,0.00085,m,

,翅片间隙：S=,0.0004,m,

,翅片距：P=,0.00085,m,

,翅片间当量直径：de=4sh/(2h+s)=,0.000647619,m,

,传热面积系数：ηc=,0.8,,

,单位管长外表面积：Fol=ηc[π(Dw2-Dg2)/2+πDg·S]/P=,0.092319951,㎡/m,

2.3,拟取冷凝器参数：,,,

,冷凝管根数：nn=,113,根,

,过冷管根数：ng=,0,根,

,管程数：Z=,2,程,

,有效管长：l=,2,m,

,垂线上的平均管子数：Ncg=,9,根,

,似取冷凝面积（内表面）Fin=nn×π×di×l=,9.570799187,,

3.,水在定性温度下的物性值：,,,

,定性温度：tm=(t1+t2)/2=,32.5,,

,定压比热：Cp=,4179,J/kg·K,

,密度：ρw=,994.9,kg/m3,

,动力粘度：μ=,7.62E-04,Pa·S,

,普兰德准数：Prw=,5.15,,

,导热系数：λ=,0.6248,w/mK,

4.,制冷剂在定性温度下的物性值：,,,

,定性温度：tmf=tk=,40,℃,

,导热系数：λf=,0.0772,W/mK,

,运动粘度：υf=,0.000000194,㎡/s,

,表面张力：σf=,5.80E-04,㎏/m,

,密度：ρf=,1133,㎏/m3,

,冷凝潜热：hfg=,166220,J/㎏,

,普兰德准数：Prf=,3.74,,

5.,管内水侧给热系数：,,,

5.1,冷却水流量：V=Qk/[Cpρw(t2-t1)]=,0,m3/s,

,,0,m3/h,

5.2,管内水速：ω=4·Z·V/[(nn+ng)πdi2]=,0,m/s,

5.3,雷诺数：Rew=diωρw/μ=,0,,

5.4,水侧给热系数：,,,

,αi=0.023(λ/di)Rew0.8Prw0.4)=,0,w/㎡K,

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6.,管外制冷剂的给热系数：,,,

6.1,毛细作用系数：βc=1－4{σf／[ρf·(Dg+h)de]}0.5／π=,0.708008732,,

6.2,单位面积热负荷：q=Qk/(nn·π·do·l·ηc)=,0,,

6.3,雷诺数：Ref=4qdmP/[ρfυf·hfg(2h+S)]=,0,,

6.4,伽利略准数：Ga=gFol3/υf2=,2.05094E+11,,

6.5,表面张力作用系数：βσ=σf（1/0.0001+2/S)/(h·ρf)=,9.033798868,,

6.6,管外给热系数：,,,

6.6.1,各种系数：,,,

①,Co=0.193βc0.5Ref-0.32Prf0.31βσ0.15Ga0.1(0.013/S)2000S=,#DIV/0!,,

②,不凝气体影响系数；设不凝气体含量为：A=,0.012,,

,η1=EXP(-15.6×A)=,0.829277864,,

③,制冷剂含油影响系数：设含油量为：B=,0.01,,

,η2=[EXP(-8.5×B)]0.8=,0.934260474,,

④,管束效应系数：η3=Ncg-0.25=,0.577350269,,

6.6.2,管外给热系数：,,,

,αo=η1η2η3Co(λf3·g/υf2)1/3=,#DIV/0!,W/㎡K,

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7.,总传热系数：（按内表面计算）,,,

,Ki=A[1/αi+di/(dmαo)+γo]-1=,#DIV/0!,,传热系数修正系数A＝1.7

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8.,对数平均温差：Δtm=(t2-t1)/ln[(tk-t1)/(tk-t2)]=,7.213475204,,

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9.,传热面积（内表面）：Fi'=Qk/(ΔtmKi)=,#DIV/0!,,

,"取5%的面积裕量,则Fi=1.05Fi'=",#DIV/0!,,

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10.,校核：Fin/Fi=,#DIV/0!,,

,∵1≤Fin/Fi≤1.05∴计算合格。,,,

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11.,水侧阻力计算：,,,

,摩擦阻力系数：ξ=