Page 2 of 4 FirstFirst 1234 LastLast
Results 14 to 26 of 40

Thread: CVHF surging

  1. #14
    Join Date
    Sep 2008
    Location
    Delaware
    Posts
    243
    Post Likes
    I agree that the "stall occures first. What happens next? If I tell guys my chiller is "stalling" it may not mean much. If it is "surging" I think more people will relate to that term. Undrestanding surge and its causes is the main idea.

  2. #15
    Join Date
    Jan 2008
    Location
    windy city
    Posts
    4,502
    Post Likes
    turbo - if you don't mind, i'll be glad to have a copy

  3. #16
    Join Date
    Oct 2004
    Location
    ca
    Posts
    69
    Post Likes

    Smile

    HI TURBOMASTER,HEY I WOULD BE INTERESTED IN READING THAT ABOUT WHAT YORK HAS TO SAY ABOUT IT.MY EMAIL IS IN MY PROFILE---THANKS PAT

  4. #17
    Join Date
    Sep 2004
    Location
    Kansas City, Kansas, United States
    Posts
    13,905
    Post Likes
    I too would like that?
    thanx

    st65

    hello Heavy!


    Quote Originally Posted by heavymetaldad View Post
    turbo - if you don't mind, i'll be glad to have a copy
    I WILL SELL WORK,GENERATE BUSINESS, GO GET NEW CUSTOMERS!
    YOU SHUT THE HELL UP AND QUIT RUNNING YOUR MOUTH!

  5. #18
    Join Date
    Sep 2004
    Location
    Kansas City, Kansas, United States
    Posts
    13,905
    Post Likes
    I always liked this from Mcquay
    Centrifugal compressors differ from positive displacement compressors (such as scroll,
    reciprocating and screw). Centrifugals are aerodynamic or turbine type. They move gas by
    converting kinetic energy to pressure energy. Positive displacement compressors encase a
    quantity of refrigerant in a decreasing volume during the compression process. They provide
    excellent lift characteristics. The advantage of centrifugal compressors is their high flow
    rates capability and good efficiency characteristics.
    The simple way to understand the principle is to imagine a ball on the end of a string. One
    person swings the ball on the string. A second person is standing the second floor balcony.
    If the person swinging the ball releases ball with enough angular momentum, the ball will fly
    up to the person on the second floor balcony. The weight of the ball (molecular weight), the
    length of the string (wheel diameter) and the rotational speed (rpm) affect the angular
    momentum.
    I WILL SELL WORK,GENERATE BUSINESS, GO GET NEW CUSTOMERS!
    YOU SHUT THE HELL UP AND QUIT RUNNING YOUR MOUTH!

  6. #19
    Join Date
    Dec 2008
    Location
    Dixiana, AL
    Posts
    2,620
    Post Likes
    Rotating stall is the condition that occurs when there's not enough mass flow of refrigerant through the impeller to displace the refgt that's already in the diffuser gap, so instead of having a nice, smooth flow on into the condenser, rotating "eddies" of gas set up in the diffuser gap. A lot of folks call this "low load surge", but actually it's just a very unstable gas flow off of the impeller and through the compressor. Mass flow rate drops due to a lot of things. The most prevalent time to see this condition is when the machine unloads (vanes, not VSD), and the cooling tower is not allowed to unload with it (condenser water temp is held towards design at the same time). Stall is the condition that occurs right before surge, but if you're in a condition that will cause a full-blown surge, you have to be real quick to hear it.

    Surge is when the delta p (lift, measured in degrees) across the impeller becomes greater than the impeller can overcome, and there is a momentary reversal of gas flow through the impeller. That reversal is what creates the severe swing in current during a surge condition. Stall and surge are definitely related, but are two different things from an operational standpoint.

  7. #20
    Join Date
    Mar 2008
    Location
    philadelphia
    Posts
    405
    Post Likes
    i wouldn't mind seeing the york info also i think my e-mail is in my profile thanks

  8. #21
    Join Date
    Sep 2007
    Location
    Somewhere in the world.
    Posts
    1,660
    Post Likes
    Here is Yorks discription of stall detection on YK with VGD variable geometry diffuser
    Attached Images Attached Images  
    A mind is like a parachute. It doesn't work if it is not open.

    The best part of going to work is coming back home at the end of the day.

    Hard work spotlights the character of people: some turn up their sleeves, some turn up their noses, and some don't turn up at all.

  9. #22
    Join Date
    Feb 2004
    Location
    Georgia
    Posts
    432
    Post Likes
    Ya'll got mail, hope that works OK. I'm not the brightest tool when it comes to sending stuff. My 19 year old son had to school me on the scanner.

  10. #23
    Join Date
    Feb 2004
    Location
    Georgia
    Posts
    432
    Post Likes
    Ditaw, my email program ain't liking your email for some reason.

  11. #24
    Join Date
    Jan 2008
    Location
    windy city
    Posts
    4,502
    Post Likes
    thanks turbo. haven't had a chance to read it. worked late tonite (again)

  12. #25
    Join Date
    Jan 2008
    Location
    windy city
    Posts
    4,502
    Post Likes
    klove - great way of putting the explanation to words

  13. #26
    Join Date
    Jan 2008
    Location
    windy city
    Posts
    4,502
    Post Likes
    hey st (weed)

Page 2 of 4 FirstFirst 1234 LastLast

Posting Permissions

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

Related Forums

Plumbing Talks | Contractor MagazineThe place where Electrical professionals meet.
Quality Home Comfort Awards