Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Fluid's boiling point dependence as function of pressure

  1. Apr 22, 2013 #1
    Greetings to all,
    I need some help for i understand how to demonstrate fluids boiling point dependence as function of pressure (i.e for main cool agents). Which are the basic equations for to write a general formula? I know that in PHWR type reactor water is at hight pressure to prevent boilling phenomena.
    Thanks a lot
  2. jcsd
  3. Apr 22, 2013 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    I don't know about a general formula, but if you consult the saturation line in any handy steam tables, you can discern a relationship between boiling point and pressure.
  4. Apr 22, 2013 #3


    User Avatar
    Staff Emeritus
    Science Advisor

    Generally, pressurized water reactors have a core inlet temperature which is subcooled, i.e., Tcoolant < Tsat. By the time the coolant about 70% of the way through the, it is possible that sub-coolant nucleate boiling occurs, i.e., the cladding surface reaches or slightly exceeds the saturation temperature. One also must bear in mind that there is a pressure drop of about 25 psid across a PWR core.

    As pressure increases, the saturation temperature increases, and there are empirical correlations for that, just as there are empirical correlations for heat transfer coefficients and fluid properties. Material properties are generally not defined ab initio.

    Here are some notes on the Jens-Lottes correlation for subcooled nucleate boiling.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook