Convective heat transfer coefficients

[Kelju Ivan]

Hi. I'm trying to make a simple model of a condensation based countercurrent heat exchanger where liquid water and steam flows are separated by a conducting wall. I formed the equations as

$$Q = \frac{T_{steam}-T_{water}}{\frac{1}{Ah_{water}}\frac{d}{Ak_{wall}}\frac{1}{Ah_{steam}}} = L\dot{m}$$

where L is the latent heat released by the condensing steam. The trouble is, I don't know the convective heat transfer coefficients. Is there a way to calculate the h-coefficients based on flow velocity or what's the deal with them?

 

[Chestermiller]

See Transport Phenomena by Bird, Stewart, and Lightfoot. The dominant heat transfer resistance is probably going to be on the water side, so you should be focusing on the heat transfer coefficient to a fluid flowing through a tube at constant wall temperature.