Results 1 to 5 of 5
  1. #1
    Join Date
    Apr 2019
    Posts
    28
    Post Likes

    Liquid Cooled Dunham Bush Refrigerant Charging Advice

    Happy Sunday! Simple question, I've always adjusted a refrigerant charge on a liquid cooled (tower) chiller using the evaporator approach method. Yes, tubes need to be in good shape. I have a 2 pass evaporator and I'm at at a 8 degrees when chiller is loaded (80%). We have a young engineer that keeps trying to tell me that approach method for charging is incorrect. It should be charged by subcooling calculation. Question; who's wrong or are we both right??

  2. #2
    Join Date
    Nov 2011
    Location
    East Side
    Posts
    6,736
    Post Likes
    You can’t just use a single measurement, you have to take everything into account. Centrifugals, I pay more attention to discharge SH, along with approach. Etc.

    I’ve never used subcooling or approach alone on a flooded machine, too many variables.

  3. #3
    Join Date
    Apr 2019
    Posts
    28
    Post Likes
    Thread Starter
    Good advice. Thank you!

  4. #4
    Join Date
    Jul 2000
    Location
    Guayaquil, EC
    Posts
    14,212
    Post Likes
    Quote Originally Posted by Chilly56 View Post
    Happy Sunday! Simple question, I've always adjusted a refrigerant charge on a liquid cooled (tower) chiller using the evaporator approach method. Yes, tubes need to be in good shape. I have a 2 pass evaporator and I'm at at a 8 degrees when chiller is loaded (80%). We have a young engineer that keeps trying to tell me that approach method for charging is incorrect. It should be charged by subcooling calculation. Question; who's wrong or are we both right??
    Is it a flooded evaporator or direct expansion?

  5. #5
    Join Date
    Apr 2019
    Posts
    28
    Post Likes
    Thread Starter
    Flooded chiller. I went by running compressors at 90% capacity and charged by the sight glass that's right before the TXV. Approach is now 7 degrees on a 2 pass evap. Running well.
    Last edited by Chilly56; 09-30-2019 at 08:22 PM. Reason: Typo

Posting Permissions

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