Page 220 - Chemical Process Equipment - Selection and Design

190 HEAT TRANSFER AND HEAT EXCHANGERS

TABLE 8.10. Recommended Individual Heat Transfer Coefficient Correlations’
A. Single Phase Streams
~~~
a. Laminar Flow, Re c: 2300
Inside tubes
N~,=$3,66~+ 1.6I3Pe(d/L), 0.1 <Pe(d/L)<lo4

Between parallel plates of length L and separation distance s

Nu, = 3.78 + 0.0156[Pe(~/L)]’.’~ 0.1 < Pe(s/L) .i io3
1 + 0.058[Pe(~/L)]~.~ ‘

In concentric annuli with d;. inside, do outside, and hydraulic diameter dh = do - 4. I, heat
transfer at inside wall; II, at outside wall; 111, at both walls at equal temperatures
Nu, = Nu,+ f(2) 0.19[Pe(dh/L)l0.*
(:r”
do 1 + 0.1 17[Pe(dh/L)10.467 (3)
Case I: Nu;, = 3.66 + 1.2 - (4)
Case If: Nu,, = 3.66 + 1.2

0.102
[
Case 111: Nu, = 3.66 + 4 - (d;./do) + 0,21(2) 0.04
4 -0.5
Case I: f - = 1 +O 14 -
’ (d,)

Case Ill: f(2) = 1 +0.14(2)0”

b. Turbulent Flow, Re > 2300
Inside tubes

Nu=0.0214(Re0~8-100)Pr0~4

Nu=0.012(Re0.87-280) ~4[1+ (az3], 1.5<Pr<500

Concentric annuli: Use dh for both Re and Nu. NbUbe from Eqs. (IO) or (11)
Nu. 2)
d. -0.16
-
0.86(
Case I: 2-
W”b*
Nu 0.6
-
1
-0.14(2)
Case 11: 2-
NUfube
NU
Case 111: 1- - 0.86(d;./d0)0’84 + I1 - 0.14~d;./do)o~61
hu be 1 + d;./d,
Across one row of long tubes: d = diameter, s = center-to-center distance, a = s/d,
q = 1 - n/4a, L = nd/2

’Special notation used in this table: (Y = heat transfer coefficient (W/m2 K) (instead of h),
q =viscosity (instead of p), and (Y =thermal conductivity (instead of k).
(Based on HEDH, 1983).