Thermal losses calculation
  • Vote Up0Vote Down sheiko May 2009
    Posts: 2
    Dear all,

    I am a french junior process engineer working in an Engineering Company.

    The context is the following:
    - The system is: inlet pipe + control valve + outlet pipe.
    - The fluid is natural gas
    - The outlet pipeline is burried.
    - No outlet pipe insulation.
    - The minimum allowable temperature in the outlet pipe is -20°C.
    - The minimum temperature at the control valve outlet flange is about -15°C (worst scenario)

    The problem is that i need to calculate the length of outlet pipe so that the fluid temperature increase to 0°C.

    My data are:
    - Outlet pipe material: carbon steel (L360)
    - Outlet pipe internal diameter: 570 mm
    - Outlet pipe thickness: 20 mm
    - Outlet pipe is burried 1 m deep.
    - Average air temperature: 11°C
    - Wind velocity: 10 m/s

    My questions are:
    1/ Do you know where i can find thermal conductivity data for ground? or do you have data? I know it strongly depends on the ground composition but i don't have anything...
    2/ Could you please share any Excel spreadsheet to perform that calculations?

    Thank you


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  • Vote Up0Vote Down hasimesk May 2010
    Posts: 1
    If you had two buildings with the same area in floor space, one is a two storey design with only four external walls. The other a single storey with eight external walls. Even though the two storey building may have a little more wall area the single storey is more complex in design having more surface area as well as corners means it losses heat at a greater rate and therefore is more energy demanding.

    Remember this, architects, designers and builders generally deal with thermal heat loss when the design is complete. You can always get better doors and windows, thicker insulation to cope with a complex design, but it cost more. A simple form means reduction in both build and running cost. :o
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