Heat Transfer Fluid Flowrate Req'd to Maintain Pipe Temp?
Heat Transfer Fluid Flowrate Req'd to Maintain Pipe Temp?
(OP)
I have a jacketed piping system using Dowtherm-A / Therminol VP-1 heat transfer vapor @ 290 Deg C to maintain a jacketed pipeline at 290 deg C. I have calculated that the heat loss thru the pipe insulation for a 10 ft long section will be approximately 2500 BTU/hr. The heat transfer fluid will be in the outer jacket and will enter as a vapor at 290 deg C, and exit as two forms, a condensed liquid and uncondensables vent. For anyone familiar with these heat transfer mediums, how do I go about calculating the vapor flow rate required to maintain the pipe temp at 290 deg C. I do have the heat transfer fluid properties.





RE: Heat Transfer Fluid Flowrate Req'd to Maintain Pipe Temp?
It will be an iterative process. Assume flow, then calculate film temperature on the inside wall of the insulation (calculate "h" for annular flow). Then look at latent heat of vaporization of Dowtherm-A at the calculated inside film temperature (heating comes predominantly from condensation of thermal fluid). Divide given Q by latent heat to get the flow. Reiterate the process till you match both "h" values. A simulator could do this quickly for you.
Dejan IVANOVIC
Process Engineer, MSChE
RE: Heat Transfer Fluid Flowrate Req'd to Maintain Pipe Temp?
Dejan IVANOVIC
Process Engineer, MSChE
RE: Heat Transfer Fluid Flowrate Req'd to Maintain Pipe Temp?
RE: Heat Transfer Fluid Flowrate Req'd to Maintain Pipe Temp?
Thank you for your assistance, however I do have a question.
How do I calculate the film temperature on the inside wall of the insulation?
RE: Heat Transfer Fluid Flowrate Req'd to Maintain Pipe Temp?
RE: Heat Transfer Fluid Flowrate Req'd to Maintain Pipe Temp?
If latent heat of vaporization of thermal fluid does not vary much with temperature, then it definitely does not matter how temperature distribution looks like, from ambient air to process fluid.
Dejan IVANOVIC
Process Engineer, MSChE
RE: Heat Transfer Fluid Flowrate Req'd to Maintain Pipe Temp?
RE: Heat Transfer Fluid Flowrate Req'd to Maintain Pipe Temp?
TTFN

FAQ731-376: Eng-Tips.com Forum Policies
Need help writing a question or understanding a reply? forum1529: Translation Assistance for Engineers
Of course I can. I can do anything. I can do absolutely anything. I'm an expert!
There is a homework forum hosted by engineering.com: http://www.engineering.com/AskForum/aff/32.aspx