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Homework Help: Thermodynamics - Find final pressure

  1. Feb 5, 2014 #1
    1. The problem statement, all variables and given/known data

    An amount of steam undergoes a constant volume process from an initial state for which the pressure and temperature are 0.1MPa and 350°C respectively. The final temperature is 300°C. Using linear interpolation estimate the final pressure.

    2. Relevant equations

    Use Thermodynamics and Transport Properties of Fluids

    3. The attempt at a solution

    I used linear interpolation for the pressure at 100°C, which was 1.01325 bar. Got my answer which was 28.3 kPa. The answer stated is 93.4 kPa
  2. jcsd
  3. Feb 5, 2014 #2
    Hi Ribz. Welcome to Physics Forums!!!

    Let me guess. You are supposed to be using steam tables to solve this, correct?

    What is being held constant in this system:
    (a) specific enthalpy?
    (b) specific volume?
    (c) specific internal energy?
    (d) specific entropy?

  4. Feb 5, 2014 #3
    Specific volume is constant
  5. Feb 5, 2014 #4
    Good. So, from your steam tables, what is the specific volume of the steam initially? Now look in your steam tables for 300C, and find a condition as close as you can get to this specific volume. What is the specific volume at that point, and at the two adjacent pressures in the table? What are the pressures and volumes that go with the three points in your table?

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