热流体冷流体
12
定性温度查物性数据
邻二甲苯自来水热流体冷流体
Ws1=30000
T1=70t1=20
00
Tm=(T1+T2)/2=tm=(t1+t2)/2=
3
45
密度比热容导热系数黏度
邻二甲苯854.71.810.1290.000529水997.24.17940.606380.000923计算对数平均温差
△tm=[(T1-t2)-(T2-t1)]/㏑(T1-t2）/(T2-t1)=
传热量Q=WhCph(T1-T2)=冷却水量Wc=Q/Cpc（t2-t1）求温差修订系数△tm=初选换热器
假设K=
u= =S估'=Q/K*△tmS估=1.15S估'
nslLNpn
估算壳体的内径ncb'D查
= = = = = = = = =
29.65
0
#DIV/0!28.23
4000.600
51.751
060000000.03750.043
6
7
壳径公称压强公称面积管程数
实际传热面积So
K
8
核算
⑴管程流通面积Ai
uiRei设管壁粗糙度查摩擦系数
△P1△P2
0.1
0.450.657.7
2 = =
管子尺寸管长管子总数管子排列方法
6124 57.4306
0
= = =0.0194680.50082216183.470.0050.0341093.33321.5677
= =
∑△Pi
⑵壳程压强降
取折流挡板间距
=
hNB
Nc = 7923.4280.319
12.249080.043132
壳程流通面积A0
uoReofo△P1’△P2'∑△Po
9
核算总传热系数①管程
ReiPriai
②壳程de
AouoReoProao10
污垢热阻
RsiRsoKo则
So’So/So'
= = = = = = = = = = =00
#DIV/0!#DIV/0!
0
#DIV/0!
16183.477.746774638.6769
0.020.029531
00
6.361665
0
0.00020.00017#DIV/0!#DIV/0!#DIV/0!
=
= = = = = = = =T2=40t2=28
0
5262
12450
139.5349
0
