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Inrease in water pressure as a function of temperature under constant volume

  1. Jun 29, 2010 #1
    Hi all. I have a large pipe network that can hold say 1000 cubic meters of water. The pipe network is closed and pressurized to say 10 barg at 25 deg C. If the temperature of the water increases to 55 deg C, how much will the pressure in the pipe network increase?

    I would appreciate if you could point out the method of solving the problem including tables and formulas.

  2. jcsd
  3. Jun 29, 2010 #2
    This ia a job for steam tables and the first law of thermo and possibly a H-S chart.
  4. Jun 29, 2010 #3
    The water is between 25 to 55 degC so I don't think the steam tables or the thermo laws will do any good. This is a pressure vs temp vs volume problem. if it was a gas then a simple ideal gas law would work.
  5. Jun 29, 2010 #4
    Steam tables, in an odd use of the nomenclature, include compressed liquid water. No idea why they are still called steam tables but they are.

    You came and asked the question as to how to solve is. I've told you. It's water, therefore you use the steam tables, there is no debate about that. You find the heat transferred to the water (using the mass and specific heat capacity). As no work is being done (from the first law) we know that all internal energy comes from transferred heat. You can then look up from a steam table the pressure.

    I've not used steam tables or done anything with thermodynamics of fluids in quite a while (since uni in fact), I can't remember exactly what you have to do i'll have to read up for that.
    Last edited: Jun 29, 2010
  6. Jun 29, 2010 #5
    It's been such a long time since uni I can barely remember any of this. I wish I had my old books. I'm doing some research on the net but it isn't easy.
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