Need sizing info for aircooled radiator

[cdcosta]

We have a reclaimed radiator type oil cooler.
We want to use it for a different application, but I have limited design information on the unit.

Can someone direct me to a good resource for basic heat transfer calculations on fintube, air-cooled radiators?

Thanks

 

[IRstuff]

Given the number of measurements you'd need to make to get any sort of accurate calculation, wouldn't it be easier to just measure the performance?

TTFN

 

[cdcosta]

IRStuff.. I was planning to do that, but It is not in service and needs to be setup to a reservoir etc. before I can do that.
I just wanted to carry out some rough cals. beforehand...

 

[Montemayor]

CDCosta:

IRstuff is absolutely right. Unless the project is worth $100,000 to 200,000 I wouldn't mess with trying to calculate the air-side film coefficients (that's what will be controlling). The results you get will be of little value unless you have empirical backup or testing on the unit. The air-side coefficients are hell to predict and worse to calculate. Few would put any faith on the results of any theoretical calculations.

If you don't want to test, then I recommend you use an overall U of 15-20 Btu/hr-ft2-oF (for water cooling) as a design figure. That's what I have found works in the past. Of course, I'm assuming you have fins in decent shape and the unit is cleaned as-new and you have good, strong air fans on it. I'm also assuming you are going to be well within the turbulent zone on the tube side. That's what I would do if I couldn't test the unit.


Art Montemayor
Spring, TX