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  1. #14
    Join Date
    Nov 2001
    Location
    Seattle, WA
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    7,819
    Consideration must be also taken to how the water cooled condenser is piped.

    It should be piped with the supply water into the bottom and out the top so that the water will fill all the piping inside the condensor and leave no air traps.

    If not piped that way air traps on the top of the tubing will form and create hot spots which will eventually lead to a bad condensor and/or high head pressure.

    The condensor should also be piped with a "reverse flow" meaning that the discharge from the compressor is piped so it meets the coldest of the supply water.

    Once those two ingredients are in place, then the water regulating valve should be mounted at the highest spot of the water cooled condenser at the exit of that condensor.

    That way all the water will not only fill all the tubing but the supply pressure from the pump/water supply will keep the water pressing up against the tubing.
    "The American Republic will endure until the day Congress discovers it can bribe the public with the public's own money.
    - Alexis de Toqueville, 1835

  2. #15
    Join Date
    Aug 2002
    Location
    Sacramento area
    Posts
    69

    Post Our installation...

    Our water cooled condensing units are connected to a closed loop cooling tower. All of the condensers are at a level lower than both the return and supply mains, so the condensers remain full of water whether the water reg valves are installed on the inlet or the outlet of the condensers.
    I'm still learning this trade.

  3. #16
    Join Date
    Nov 2001
    Location
    Seattle, WA
    Posts
    7,819
    Quote Originally Posted by uhPrintUs View Post
    Our water cooled condensing units are connected to a closed loop cooling tower. All of the condensers are at a level lower than both the return and supply mains, so the condensers remain full of water whether the water reg valves are installed on the inlet or the outlet of the condensers.
    Well maybe, maybe not. Here's a point I'm sure will bring a discussion. It still depends on how your water cooled condensors are piped. If the water supply comes in the top and circulates down to the exit through the bottom there still exists the great possibilites that all of the water in the tube is not making a solid contact against the entire tube, especially the top of the tube, thereby making the unit less efficient as there is less heat transfer and causing an unnecessay higher head pressure.

    That would even be more the case if the water regulating valve would be on the inlet side of the water cooled condensor as the water would be subject to the return side of the pump and not to the high side pressure of the pump.
    "The American Republic will endure until the day Congress discovers it can bribe the public with the public's own money.
    - Alexis de Toqueville, 1835

  4. #17
    Join Date
    Jun 2010
    Location
    Miami
    Posts
    258
    Seems to me this is getting silly. If we are talking top and bottom then we have a shell and tube heat exchanger. Those that are designed for tower water ideally will have a three pipe connection for tower water. Inlet water is bottom and top, the outlet is the middle. The difference between supply and return pressure is low, typically only a few psi. Regulator goes on inlet side and is controlled by cap tube connected to the head of the compressor. The heat exchange will always be totally full of water and any time the compressor runs the regulator will be open to some degree. It should close completly when the compressor cycles off and high pressure falls low enough. The return water piping has a positive pressure and isn't running a vacuum so it isn't going to drain the condenser when the regulator valve shuts off. The water should be treated and the compressor should run often enough that no fouling takes place. Delta T on the water side should be fairly low and water discharge temp shouldn't be more than 100 degrees under any condition.

    The hot gas discharge line has to enter the top of the condenser shell and the liquid line has to be taken off the bottom of the shell. Unless the shell is totally flooded you simply can't get liquid of the top of the shell. Rather it is an air handler coil or a water cooled condenser you want the coldest air meeting the coldest water or the coldest freon meeting the coldest water. After all the hot gas is going to be upwards of 200 degrees. If you allow your inlet water to see that you might not have any water left that is cold enough to get your liquid freon down to 105 SCT and subcooled.

  5. #18
    Join Date
    Aug 2006
    Location
    st.petersburg,fl
    Posts
    806

    Lightbulb

    This argument is going nowhere fast... No matter how you look at it... each side is right and not gonna waver... I know i'm not gonna give on my position and neither is anybody else....

    There now I said it.. And we can now move on to the next issue whatever it may be...


    Isn't sanity just a one-trick pony anyway? I mean, all you get is that one trick, rational thinking, but when you're good and crazy, well, the sky's the limit!

  6. #19
    Join Date
    Apr 2005
    Location
    where the beer flows like wine
    Posts
    2,871
    Quote Originally Posted by DeltaT View Post
    Consideration must be also taken to how the water cooled condenser is piped.

    The condensor should also be piped with a "reverse flow" meaning that the discharge from the compressor is piped so it meets the coldest of the supply water.
    I thought "counterflow" means; when the entering coldest water meets the leaving subcooled liquid first and the warmest water desuperheats the discharge from the compressor.

  7. #20
    Join Date
    Nov 2001
    Location
    Seattle, WA
    Posts
    7,819
    Note the last paragraph fo the tube/tube type condenser & the associated piping pictures as some examples.


    Water-Cooled Condenser
    Many large commercial refrigerating units use a water-cooled condenser. This condenser is built in three styles:
    Shell and tube.
    Shell and coil.
    Tube-within-a-tube.
    In the first type, the refrigerant vapor goes directly from the compressor into a tank or shell. At the same time, water travels through the tank or shell in straight tubes. The second type also uses a shell. However, the water travels through the shell in coils of tubing.
    The third type uses two pipes or tubes—one inside the other. The refrigerant passes one way through the outer pipe. The condenser water flows in the opposite direction through the inner tube. Water velocity should be 7-10 fps (2.13-3.04 m/s). If flow is too fast, water may remove the oxide coating, causing pitting. If the water velocity drops to 3 fps (0.3 m/s), scaling will occur.

    Also see the piping pictures on:
    http://www.hvactroubleshootingguides...ondensers.html
    "The American Republic will endure until the day Congress discovers it can bribe the public with the public's own money.
    - Alexis de Toqueville, 1835

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