Wall temperature 1

[mfqd13]

Hi, i'm designing a heat exchanger. I have a tube bank and i want to calculate the exterior tube wall temperature, so that i can calculate the film temperature: Tf=(Tw + Tinfinite)/2. I don't have the heat transfer coefficient, so i have to play only with the temperatures of the fluids (inside and outside). I remember a formula where i used DTML, and with an iterative proccedure it can be calculated this wall temperature, but i forgot....

Can anyone help me?

Thanks

 

[Christine74]

You won't be able to do this calculation without knowing the individual film coefficients, because the wall temperature will be closer to the stream temperature of the side with the larger film coefficient.

A procedure for calculating the tube mean metal temperature is available in TEMA T-4.32. The internal/external skin temperatures should be very close to the mean metal temperature for metallic tubes.

-Christine

 

[athomas236]

marcosdias,

You might an interative solution works, guess the wall temperature, calculate the coefficients then calculate the wall temperature. Repeat till guessed wall temperature is near enough to calculated wall temperature.

Regards,

athomas236

 

[mfqd13]

athomas236,

thank you for your answer, and i think my initial guess was most aproximate to yours.

Christine74,

thank you very much, also for your answer, but is there any way that i can access TEMA T-4.32, because i don't have one.
Is there any download link where i can view this chapter?