Heat Transfer Rate

[oleksad]

I have a cylindrical container of water at 200 degrees F. The container has a height of 21", a diameter of 15" and is 5/16" thick. It is made of HDPE. The outside temp. is 70 degrees F. How can I calculate the heat transfer rate?

 

[MintJulep]

Put a thermometer in the water and monitor how fast the temperature falls.

 

[reidh]

Do you have a heater keeping it at 200 deg F, or is this just the initial temperature?

Either way, it is a simple conduction/convection problem, conduction through the walls, convection to the ambient air. You need the heat transfer coefficient of the HDPE to solve this problem, which should be easy to find.

Also, I believe the max. temperature rating for continuous use of your average HDPE is right around 200 F. I don't know your application, but you should be careful operating near the maximum temperature limit.

Reidh

 

[stanlsimon]

You need to find the R value of the HDPE, the inside convective heat transfer coefficient, and the outside heat transfer coefficient. I can't tell you a exact number for the heat transfer coefficients, because you didn't say if this is forced convection with fans and pumps or natural convection.

Assuming you have natural convection, you can get close by figuring an overall U value of between 2-4 btu/hr/square foot/Deg F.
Then you heat transfer calculation will be U x A x TD.

If forced convection is involved multiply times 2.5.