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  1. #1
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    Specific heat of R134a



    Hi,

    I'm new to this forum and I have a question about the specific heat of R134a during the condensing phase in the refrigeration cycle.

    I am currently trying to assess the impact of increasing seawater inlet temperature (as cooling medium) on the cooling capacity (Q) of the Chilled water plant. I have estimates for mass flow but i can't find a figure for specific heat for R134a at 70 deg C as it enters the SW condenser. So far i have only found the specific heat of R134a at 0 deg C saturation which is 1.34 kJ/kg.K.

    Secondly, this may be a silly question but would I be correct in assuming that the specific heat of R134a changes as it condenses at 40 deg C at constant pressure as an example. How do you account for the temperature glide as the refrigerant is superheated at 70 deg, condenses at 40 deg, and then is sub cooled at 30 deg C???

    Sorry so many questions but i would appreciate if someone could help me out.

    Cheers

    Clint



  2. #2
    Join Date
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    Re: Specific heat of R134a

    Hi, clint84

    Welcome to RE forums ...


    Quote Originally Posted by clint84 View Post
    Hi,

    I'm new to this forum and I have a question about the specific heat of R134a during the condensing phase in the refrigeration cycle.

    I am currently trying to assess the impact of increasing seawater inlet temperature (as cooling medium) on the cooling capacity (Q) of the Chilled water plant. I have estimates for mass flow but i can't find a figure for specific heat for R134a at 70 deg C as it enters the SW condenser. So far i have only found the specific heat of R134a at 0 deg C saturation which is 1.34 kJ/kg.K.

    Secondly, this may be a silly question but would I be correct in assuming that the specific heat of R134a changes as it condenses at 40 deg C at constant pressure as an example. How do you account for the temperature glide as the refrigerant is superheated at 70 deg, condenses at 40 deg, and then is sub cooled at 30 deg C???

    Sorry so many questions but i would appreciate if someone could help me out.

    Cheers

    Clint
    If you take a time to search RE forums for sure you'll find your answer and much more ....

    There is no silly question/s, but sometimes answer/s can be silly, see my sig



    anyhow ... check with Google for CoolPack program .... free and mighty to give you a lot of possibilities to virtually play with any refrigeration plant you like ...

    There you have Log(p)-h diagrams, T-s diagrams, h-s diagram, saturation table for many refrigerants and much more .... you can see and plot your refrigeration cycle .... I believe you'll like it ... enjoy

    Hope this will help you ....

    Best regards, Josip

    It's impossible to make anything foolproof because fools are so ingenious...

    Don't ever underestimate the power of stupid people when they are in large groups.

    Please, don't teach me how to be stupid....
    No job is as important as to jeopardize the safety of you or those that you work with.

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