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Heat exchanger design query

  1. Sep 20, 2009 #1
    I need to design a concentric heat exchanger. I have steam flowing on the shell side( annular region of the heat exchanger) at 2 bar and water flowing on the inside. I am maintaining constant wall temperature with steam flow. How should i size the length of the heat exchanger and how should i decide the steam flow rate for a given heat load. Also before the water is sent into the heat exchanger i am letting it flow through a calming section. How should i size the length of the calming section. Please give me the considerations i need to do. Please cite external references for calculations.
  2. jcsd
  3. Sep 20, 2009 #2
    Where is this heat exchanger located? In your house, neighborhood? etc ...

    2 bar is about 30 psia which would make it be at about 15 psig. That would make your heat exchanger a pressure vessel in the United States. Are you in the United States? If so you must follow the rules of the American Society of Mechanical Engineers (ASME) pressure vessel code.

    At 2 bar the saturation temperature is 250 F (121 C) that steam can cause burns. Have you taken any precautions for overpressurization such as a pressure operated relief valve?

    As for your "calming" section, I am assuming that you are trying to have laminar flow enter the exchanger. Why? Turbulent flow promotes much better heat transfer.

    As far as mass flow, what are you trying to do with steam?

    If you are not capable of designing this heat exchanger on your own and it operates in an area where people can be harmed if it losses steam or explodes, I recommend you hire a professional engineer for help before you continue any further.

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