1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Thermodynamics Steam Turbine Internal Efficiency Question

  1. Dec 10, 2012 #1
    1. Steam into a steam turbine at 7 MPa and 500 deg C. The turbine has an internal efficiency of 90 %. The steam exhausts at 20 kPa.

    1) What is the exhaust enthalpy?
    2) What is turbine work?
    3) What is the quality of the exhaust steam?

    This is a question I got on a 2nd class boilers branch thermodynamics exam, can anyone tell me what is the equation for internal efficiency of a steam turbine?

    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Dec 10, 2012 #2

    SteamKing

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    Check out the following article:

    [/PLAIN] [Broken]

    Scroll down until you reach the section titled "Isentropic Turbine Efficiency"
     
    Last edited by a moderator: May 6, 2017
  4. Dec 10, 2012 #3
    I don't see any link steamking.......????
     
  5. Dec 10, 2012 #4
    Hi Frock,
    The equation I suspect you are looking for is as follows:

    efficiency (turbine) = Actual turbine work / isentropic turbine work
     
  6. Dec 10, 2012 #5

    SteamKing

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

  7. Dec 11, 2012 #6
    Thanks for all the replies guys. It was so simple, I am embarrassed. I have never heard Isentropic Efficiency referred to as Turbine Internal Efficiency and that threw me. If I didn't go into panic mode in the exam and had thought about it as Isentropic then I would have seen that the info they had given pointed to Isentropic. Once again thanks for the help.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Thermodynamics Steam Turbine Internal Efficiency Question
Loading...