8.02
Q:
How is the tube-side heat transfer coefficient h
i estimated?
A:
The widely used expression for hi is [1]
Nu ¼ 0:023 Re0:8 Pr0:4 ð8Þ
where the Nusselt number is
Nu ¼
h
idi
12k ð9Þ
the Reynolds number is
Re ¼ 15:2
wd
i
m
ð10Þ
where w is the flow in the tube in lb=h, and the Prandtl number is
Pr ¼
mCp
k ð11Þ
where
m ¼ viscosity, lb=ft h
Cp
¼ specific heat, Btu=lb F
k ¼ thermal conductivity, Btu=ft h F
all estimated at the fluid bulk temperature.