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  1. #1
    Join Date
    Oct 2003
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    Speed in a tube, how to calculate



    You have a single pipe - let's say 1/2" - and you use this as an evaporator, submerged in water.
    Tc = 40°C, Te= 0°C, let's say R134a
    At the inlet a TEV, inlet SC liquid with 3K, outlet SH of 5K.
    Second situation: SC of 20K.
    I'm a little bit confused: in the 1st situation, we will have refrigerant with a lower quality than the situation with 20K. If we have 20K SC, and we used the outlet conditions to calculate the needed diameter of this coil (1/2"), will we then not have very high liquid speeds in the first parts of the tube, provoking a large DP in the first meters of the coil?


    It's better to keep your mouth shut and give the impression that you're stupid than to open it and remove all doubt.

  2. #2
    Join Date
    Nov 2009
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    Minsk, Belarus
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    Re: Speed in a tube, how to calculate

    Yes you haven't. If you have the same outlet conditions, SC 20K and the same refrigerating capacity than you'll have less refrigerating mass-flow (less volume flow through TEV and after)... pressure drop in coil (1/2") will be less.
    In some places will have to think ...

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