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  1. #1
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    design a condenser with 12 K subcooling



    Hi All,

    I am presently facing an engineering hurdle.

    I am trying to design a system that gives an off coil of 5 Deg C, looking at refrigeration temp at -5 Deg C.

    I am now trying to design the condenser. The refrigerant temp at discharge is 50 Deg C, RFRIGERANT used : R22/R423

    I am looking at a subcooling of 12K which means after condeners I want the refrigerant temp to be 38 Deg C.

    Ambient air : 35 Deg C / 5 Deg C

    can anyone advice on how I should design the condenser ?

    Please advice.

    Warmest Regards
    SkiLLet



  2. #2
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    Re: design a condenser with 12 K subcooling

    .

    Free subcooling can only be achieved at about 4 degsK maybe 6 degsK
    and it is only possible to cool down to the ambient temperature.

    In air conditioning systems they get round this problem with an over sized
    condenser and fan speed control or they bring the liquid back to the bottom
    of the condenser and make a few extra passes. This allows the liquid to reject
    some heat to the ambient but it is only possible down to the ambient temps.

    The over sized condenser also acts as a liquid receiver and stores the liquid
    before use in the expansion device.

    You could try designing a larger condenser with an extra subcooling section on
    the bottom.

    Another way is to use adiabatic cooling (water and air) if you spray water over
    the condenser as you pass air over it the evaporation effect will lower the temperature
    even further.

    You could run your liquid line inside your suction and that will exchange the heat
    to the suction gases.

    Or you could pass your liquid line through a plate heat exchanger and then
    increase the subcooling with a small refrigeration circuit built into your main system.
    Using this subcooling method you may use 10% of the liquid refrigerant in the subcooling
    process but if done properly it will increase your liquid quality up by as much as 30% or 40%.

    Regards

    Rob

    .
    Last edited by Rob White; 27-02-2013 at 02:13 PM.
    .. ... -. .----. - / -- --- .-. ... . / -.-. --- -.. . / --. --- --- -..

  3. #3
    TRASH101's Avatar
    TRASH101 is offline Veteran Poster I am starting to push the Mods: of RE
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    Re: design a condenser with 12 K subcooling

    You are describing a temperature differential there aren't you ??? not subcooling unless you got liquid coming into the condenser.

    You want to clarify?
    Quidvis Recte Factum Quamvis Humile Praeclarum.

    Latine dictum, sit altum videtur.

    Si hoc comprehendere potes, gratias age magistro Latinae.

  4. #4
    TRASH101's Avatar
    TRASH101 is offline Veteran Poster I am starting to push the Mods: of RE
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    Re: design a condenser with 12 K subcooling

    Well put there Rob btw
    Quidvis Recte Factum Quamvis Humile Praeclarum.

    Latine dictum, sit altum videtur.

    Si hoc comprehendere potes, gratias age magistro Latinae.

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