Results 1 to 10 of 10

Thread: Cracked/frozen chiller air-cooled condenser

  1. #1
    Join Date
    Jun 2020
    Posts
    5
    Post Likes

    Question Cracked/frozen chiller air-cooled condenser

    Hi. A chiller (from a pack) has the (screw) compressor and evaporator mounted inside a housing, and the condenser mounted outside (on the top of the building). The chiller was not used during winter. At the beginning of summer, both the evaporator and the condenser were found with cracked pipes due to water freezing.
    My question is: is it possible that the water from the evaporator (that cracked first) to migrate (due to pressure difference between the cracked refrigerant and water circuits) to the condenser through the compressor or otherwise, and crack it as well during subsequent freezing ?
    Attached Thumbnails Attached Thumbnails Pallas-01.jpeg   Pallas-05.jpeg   Pallas-06.jpeg  

  2. #2
    Join Date
    Jan 2015
    Location
    Somewhere making cold water
    Posts
    324
    Post Likes
    Once water is in the system it’s everywhere.
    Boat anchor now.


    Sent from my iPhone using Tapatalk

  3. Likes CHILLERSVCMAN liked this post.
  4. #3
    Join Date
    Aug 2019
    Location
    LA
    Posts
    166
    Post Likes
    Is this an air cooled DX unit and if so I would not think if the evap broke first that the condenser would fill up on the roof. Looks more like over pressure failures to me

  5. #4
    Join Date
    Jun 2020
    Posts
    5
    Post Likes
    Thread Starter
    It's a T***E RTUD220 unit. If overpressure, then why so many holes ? one should have been enough to release the pressure.

  6. #5
    Join Date
    Sep 2002
    Posts
    30,295
    Post Likes
    There really is no other answer than that the chiller failed first and that put liquid water into the refrigerant tubes of the air cooled condenser.

    This would require that the feed water to the chiller was valved on at the time. Water solely in and from the chiller barrel would not be sufficient to fill the refrigerant lines and the condenser. For one thing; as soon as the chiller tube failed at least some of the water would have been in the chiller / compressor refrigerant circuits. Feed water Was left on or badly leaking through.

    How interesting are the failure sites at the condenser? Every one appears to be at the weaken copper resulting from brazing the return bends. <g>

    With in-house labor the chiller and the condenser can be saved but probably not the compressor. I'd want that out for baking, a rewind, and mechanical rebuild.

    Who built the condenser?

    Are they rifled condenser tubes?

    PHM
    ---------




    Quote Originally Posted by crios339 View Post
    Hi. A chiller (from a pack) has the (screw) compressor and evaporator mounted inside a housing, and the condenser mounted outside (on the top of the building). The chiller was not used during winter. At the beginning of summer, both the evaporator and the condenser were found with cracked pipes due to water freezing.
    My question is: is it possible that the water from the evaporator (that cracked first) to migrate (due to pressure difference between the cracked refrigerant and water circuits) to the condenser through the compressor or otherwise, and crack it as well during subsequent freezing ?
    PHM
    --------
    The conventional view serves to protect us from the painful job of Thinking

  7. #6
    Join Date
    Jun 2020
    Posts
    5
    Post Likes
    Thread Starter
    This is not a repair, but an insurance matter. The owner blames a faulty water valve that did not open in order allow water circulation through evaporator as an anti-freeze protection measure.
    Another issue is that the compressor and the evaporator are mounted "in-house" in a heated room !. They put the freezing on behalf of refrigerant migration (?) from the evaporator to the condenser due to indoor-outdoor temperature differences (during winter)

  8. #7
    Join Date
    Aug 2019
    Location
    LA
    Posts
    166
    Post Likes
    Question is how did water get from the chilled water side through evap to the condenser with out going through the barrel. I only see pics of coils

  9. #8
    Join Date
    May 2015
    Location
    LA
    Posts
    74
    Post Likes
    Quote Originally Posted by crios339 View Post
    This is not a repair, but an insurance matter. The owner blames a faulty water valve that did not open in order allow water circulation through evaporator as an anti-freeze protection measure.
    Another issue is that the compressor and the evaporator are mounted "in-house" in a heated room !. They put the freezing on behalf of refrigerant migration (?) from the evaporator to the condenser due to indoor-outdoor temperature differences (during winter)
    That makes no sense if the system was off and all pmps off ect and we have an air cooled condenser and the evap and compressor are in a heated room there's no way it would get below freezing break then somehow fill the condenser unless the condenser is the lowest point of this system?
    Frist guess is someone /something messed up and chiller ran with no water flow (bad safetys?) Then once system lost its charge if the pump kicked on it could maybe pump to the roof? If that's freezer breaks it had to be filled just water not just a little bit. Is the compressor full? I would walk away form this job something not adding up was the system in bad shape p? Might be a con job....

  10. #9
    Join Date
    Sep 2002
    Posts
    30,295
    Post Likes
    That explanation appears flawed from a mechanical and logical point of view.

    The owner's position would first require that the heating failed, that no one discovered the failure, and that the failure continued for a time sufficient to so solidly freeze a unit not exposed directly to outdoor ambient.

    Is the space heating to the chiller barrel area independent of all other areas?
    Is there never any occupant or maintenance or security activity in the chiller area?

    The owner's position would also require that substantial refrigeration-effect occurred in a system simultaneously vented to the water system And flooded with water - while containing little remaining refrigerant. None of it being the liquid refrigerant which is required for the change-of-state necessary to produce refrigeration-effect.









    Quote Originally Posted by crios339 View Post
    This is not a repair, but an insurance matter. The owner blames a faulty water valve that did not open in order allow water circulation through evaporator as an anti-freeze protection measure.
    Another issue is that the compressor and the evaporator are mounted "in-house" in a heated room !. They put the freezing on behalf of refrigerant migration (?) from the evaporator to the condenser due to indoor-outdoor temperature differences (during winter)
    PHM
    --------
    The conventional view serves to protect us from the painful job of Thinking

  11. #10
    Join Date
    Jan 2008
    Location
    East of big city prices.
    Posts
    3,864
    Post Likes
    So it would appear that this is a remote condenser (split chiller ). Not sure what climate you are in but I’ll presume colder than mine.

    The refrigerant migrated to the condenser this causing the saturated suction temperature to drop below freezing. Since your evaporator is located inside I a, going to think you have a fresh water application. So water freezes at 32 . So without waterflow or a glycol medium down at the
    evaporator then the evaporator froze. Then the water mixed with the refrigeration system and went to the condenser .

    The bulges you showed on the copper piping means water inside the condenser froze due to an ambient freeze and split.

  12. Likes Nuclrchiller liked this post.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •