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  1. #1
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    Unhappy Low Evaporating Temp TXV



    How to set TXV temperature in Brazed Plate Heat Exchanger. I am assembling a chiler for water temperature of 34 degree F. The temperature range printed on TXV is from -49 to +50 F 



  2. #2
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    Re: Low Evaporating Temp TXV

    What kind / brand is your TXV?
    To make progress is never good enough, I want to do better and better and better

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    Re: Low Evaporating Temp TXV

    It is Danfoss TEX2 for R22

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    Re: Low Evaporating Temp TXV

    What's the evaporating temperature and superheating that is concern to the selection of the plate heat exchanger?
    To make progress is never good enough, I want to do better and better and better

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    Re: Low Evaporating Temp TXV

    The target Evaporating temperature is 35 F or 2 C. Not sure about superheat
    What kind of design chanes required for different evaporating temperatur like very low temperature freezers for ice cream hardning

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    Re: Low Evaporating Temp TXV

    Quote Originally Posted by nadeem.usmani View Post
    The target Evaporating temperature is 35 F or 2 C. Not sure about superheat
    Please inform about the inlet and outlet water temperature.
    To make progress is never good enough, I want to do better and better and better

  7. #7
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    Re: Low Evaporating Temp TXV

    Sorry for late reply The detail of the chiller is as following

    It is a water chiller for a Bakery

    Ref Capacity 10 ton
    Tank Capacity 90 gal
    Water Circulation 30 gal / min
    Delta Temp 10 C
    Required wter temp 2 C
    Water Draw from tank 30 gal after every 20 miniuts

    I think I have made a mista to ask you the design Evap temp of 2 C or 34 F. I think it should be some where minus 5 C (to achive 2 C water)

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    Re: Low Evaporating Temp TXV

    What is the PHE capacity?
    The TXV size has to fit that capacity regardless the evaporting temp. When you get this info, you can determine the condensing unit size, Or you can check your 10 ton refrigeration unit capacity at -5C and then work out the TXV size and PHE capacity at your required water flow and leaving temp.

    Remember that water freezez at 0C so you might need to add some glycol but that will decrease the unit capacity.

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    Re: Low Evaporating Temp TXV

    That's right chemi-cool. But you have to keep in mind that the "size" of the TXV is also affected by the evaporating temperature. Lowering the evaporating temperature less capacity it allows considering the same superheat.
    To make progress is never good enough, I want to do better and better and better

  10. #10
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    Re: Low Evaporating Temp TXV

    My basic question is still there
    How to lower the evap temp setting of TXV
    The way I understand the factory setting is @ 7 C
    How to make it -5 C

  11. #11
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    Re: Low Evaporating Temp TXV

    watch out for the low temps in your plate evap. remember the 4C fase change of water!!

    if yore flow is not strong enough.....sh...t will happen

    Ice

  12. #12
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    Re: Low Evaporating Temp TXV

    Quote Originally Posted by nadeem.usmani View Post
    My basic question is still there
    How to lower the evap temp setting of TXV
    The way I understand the factory setting is @ 7 C
    How to make it -5 C
    Why do you say it came 7C. The valve adjust itsel to new dynamic conditions. The thing you can some how adjust is the superheat but even so it can vary depending of the moment liquid demand.
    To make progress is never good enough, I want to do better and better and better

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