Results 1 to 12 of 12
  1. #1
    Join Date
    Jan 2006
    Location
    Ontario
    Posts
    9
    Rep Power
    0

    New person says hi and looks for p/h chart for R-12



    Hi
    I am new here
    I am not use to the site yet and I was searching for a "pressure/ enthalpy chart for refrigerant 12
    I found the heading in the site which I have listed below, but I was unable to open it.

    Links and Downloads Database
    Pressure-Enthalpy Chart

    My request is if any body can lead me to a P/h chart for refrigerant 12
    My instructor gave us one which is barely readable so I got one from the net BUT, the
    KJ/Kg is way off base.
    I do not understand and my instructor can not say why.

    I am in 3rd year marine engineering and doing air conditioning in my 3rd thermodynamics.
    The chart which is barely legible, that our instructor handed out, works with our calculations from the text book (Basic Engineering Thermodynamics by Rayner Joel) so we will be using it to prepare for our 1st class Marine Engineering test after graduation.

    I would like to find a chart that I can see clearly and that has the proper enthalpy scale.
    Thank you in advance

    I hope to add to the forum on a regular basis.



  2. #2
    Join Date
    Aug 2005
    Location
    USA
    Posts
    5,326
    Rep Power
    25

    Re: New person says hi and looks for p/h chart for R-12

    Welcome to the forum,

    You said the enthalpies were not correct on one of the charts. My question is, how are they not correct? Do they not compare favorably to another chart?

    One thing you should be aware of on these charts is that they can be different. Sometimes the charts (and tables for that matter) can be based on different reference temperatures.

    In some charts, the zero enthalpy is based on Zero, in others the reference temperature is -40. If you compare one enthalpy from one chart to another chart, it is possible that the enthalpies for the same point will be different. Same for some refrigerant tables.

    Whenever you are doing mass flow calculations or other procedures using the refrigerant PH chart or tables, you need to make sure that the Zero enthalpy reference is the same.

    DO NOT use different charts or tables as they will lead you to make incorrect calculations.

    I suspect this is the problem you are experiencing.

    As to the problem of the link not working, I will have to check this. It worked when I posted it, but for some reason is not, now.

  3. #3
    Join Date
    Oct 2001
    Location
    Nottingham UK
    Posts
    5,733
    Rep Power
    51

    Re: New person says hi and looks for p/h chart for R-12

    http://www.et.web.mek.dtu.dk/Coolpack/UK/download.html

    Download COOLPACK and within the program go to Refrigeration Utilities.

    You can print off P/T charts for any refrigerant

  4. #4
    Join Date
    Oct 2001
    Location
    Nottingham UK
    Posts
    5,733
    Rep Power
    51

    Re: New person says hi and looks for p/h chart for R-12

    OOps sorry

    Just noticed at the bottom of the page you can download Refig Utilities seperately

  5. #5
    Join Date
    Jan 2006
    Location
    Ontario
    Posts
    9
    Rep Power
    0

    Re: New person says hi and looks for p/h chart for R-12

    Thank you everyone

  6. #6
    Join Date
    Jan 2006
    Location
    romania
    Age
    59
    Posts
    6
    Rep Power
    0

    Re: New person says hi and looks for p/h chart for R-12

    Hi,
    I need the Molier diagram (T-s) for water. Please help me

  7. #7
    Join Date
    Aug 2005
    Location
    USA
    Posts
    5,326
    Rep Power
    25

    Re: New person says hi and looks for p/h chart for R-12

    Hi marianstancu,

    Here is a copy of the information you requested. I hope this is useful.

    Best Regards,
    US Iceman
    Attached Files Attached Files

  8. #8
    Join Date
    Mar 2005
    Location
    USA
    Age
    76
    Posts
    639
    Rep Power
    20

    Re: New person says hi and looks for p/h chart for R-12

    Something I remember from days gone bye...especially on R-12, different manufacturers of the refrigerant used a different base line for the R-12 and had different enthalphy valuses at a specific condition. When you are working on a heat balance, all you are concerned with the the differences in enthalphy anyway.

    Ken

  9. #9
    Join Date
    Jan 2006
    Location
    romania
    Age
    59
    Posts
    6
    Rep Power
    0

    Re: New person says hi and looks for p/h chart for R-12

    Thank you US Iceman.
    Best regards, Marian

  10. #10
    JORGE's Avatar
    JORGE Guest

    Re: New person says hi and looks for p/h chart for R-12

    Hi! Thank You Us Iceman
    Jorge

  11. #11
    lucky_jenie's Avatar
    lucky_jenie Guest

    Re: New person says hi and looks for p/h chart for R-12

    Thanks, im need it to do my report.

  12. #12
    Greener's Avatar
    Greener Guest

    Re: New person says hi and looks for p/h chart for R-12

    Quote Originally Posted by TXiceman View Post
    Something I remember from days gone bye...especially on R-12, different manufacturers of the refrigerant used a different base line for the R-12 and had different enthalphy valuses at a specific condition. When you are working on a heat balance, all you are concerned with the the differences in enthalphy anyway.

    Ken
    Hello,

    I also have found that different manufacturers and textbooks use different reference temperatures for their p/h diagrams.

    Can anybody tell me why this is?

    Coolpack seems to match the enthalpies to the relevant saturation temperature / pressure. Why isn't this the case for all other p/h diagrams?

    Thank you.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •