Hi guys:

I need to compute a coil for ammonia Heat exchanger

and i have the following dates:

Q = 400000 Kcal/h
T cold fluid = -22ºC (NH3)
T Hot fluid = -15 º C ( Brine sodium chloride)

IF i use

Q = (Tc - Th) x U X A

For calculate "A"

I need to Know "U" the overall heat transfer coefficient but The determination of U is often tedious and needs data not yet available in preliminary stages of the design somebody has typical values of U for quickly estimating the required surface area. I hope that somone can help me.

PD: This coil works in a flooded system.

Best regards.


Luis