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  1. #1
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    Ice rink brine temperature? for ambient temperature above the ice surface +24°С



    Hi, This is Aykut. I have a question about ice rink design.

    Our Ice Rink Technical specification ;

    -size of the ice rink; 806m2
    -ambient temperature above the ice surface;+24°С
    - relative humidity above the ice surface;50%
    - air velocity above the ice surface;0,2m/sec
    - ice thickness;40mm
    - required cooling capacity;≈280kW
    Refrigerant;R-404A
    Outdoor Temperature;+40°С

    We have two offer and two different disegn;

    First offer;

    Semi hermetic screw compressors (2+1) 1pcs.
    - type Bitzer or similar

    - cooling capacity 291,0kW
    - evaporating temperature -17°С
    - condensing temperature +50°С
    - power consumption 224,0kW

    Pipe & tube heat exchanger 1pcs.
    - type Alfa-Laval or similar

    - capacity 460,0kW
    - evaporating temperature -17°С
    - glycol inlet temperature -9°С
    - glycol outlet temperature -12°С
    number of circuits 3pcs

    Second offer;

    Semi hermetic screw compressors (3+1) 1pcs.
    - type Bitzer or similar
    - cooling capacity 282,0kW
    - evaporating temperature -22°С
    - condensing temperature +50°С
    - power consumption 200,0kW

    Pipe & tube heat exchanger 1pcs.
    - type Alfa-Laval or similar
    - capacity 320,0kW
    - evaporating temperature -22°С
    - glycol inlet temperature -14°С
    - glycol outlet temperature -17°С

    Which glycol inlet&outlet temperature true? (-9°С /-12°С or -14°С /-17°С)



  2. #2
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    Re: Ice rink brine temperature? for ambient temperature above the ice surface +24°С

    first one better than second one
    less compressor - more capacity in heat exchanger but ask them to reduce his design to -14°С /-17°С to get
    better ice and hard ice with less time during ice up time.look like they have to change model of compressor

    you asked . Which glycol inlet&outlet temperature true? (-9°С /-12°С or -14°С /-17°С)
    both is true only design is different and delta T is same (3)

  3. #3
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    aykut Guest

    Re: Ice rink brine temperature? for ambient temperature above the ice surface +24°С

    thanks for answer but i have doubt about ice temprerature for ambient +24°С

    if glycol inlet&outlet temperature -9°С /-12°С then ice temperature will be +1,16°С
    if glycol inlet&outlet temperature -14°С /-17°С then ice temperature will be -4С(it s true)

    according to ice temperature formulas;

    tm = ta – ((ta – ti) / Θ))

    • tm – cooling medium temperature (°C); (glycol outlet temperature)
    • ta – ambient air temperature (°C);
    • ti – ice temperature (°C);
    • Θ – ice layer relative (it is only coefficient)

    Θ=2•π•λc/(ε•α•ln((2•ε)/(π•d)•sh(2•π•(h+λc/α)/ε)))

    • ε – distance between pipe loops (m);
    • α – heat-transfer factor W/m2•K;
    • h – equivalent heat resistance layer;
    • d – pipe diameter (m);
    • λc - concrete heat conductivity (W/m•K).
    • sh – hyper sinus

    α=(Q-q)/(ta-ti)

    • Q – total heat load (kW);
    • q – heat load through the ground (kW).

    h=d/2+δc+δi•(λc/λi)

    • δc – concrete layer thickness above the pipe loops (m);
    • δi – ice layer thickness (m);
    • λi - ice heat conductivity (W/m•K).

    • ta = +24°C, customer request;
    • ti = - 4°C, customer request;
    • ε = 0.08m, ice rink standard solution;
    • d = 0.025m, ice rink standard solution;
    • λc = 1.75W/m•K, physical properties tables;
    • λi = 2.21W/m•K, physical properties tables;
    • Q = 264.64kW, taken from HUURRE calculation;
    • q = 6.53kW. not mentioned in HUURRE calculation so i use 8.1W/m2;
    • δc = 0.032m, ice rink standard solution;
    • δi = 0.04m, customer request.

  4. #4
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    Re: Ice rink brine temperature? for ambient temperature above the ice surface +24°С

    one question, why haven you you used method of heat resistances with heat source? And coudl you tell me where have you found this formula? could you post a link or anything else which will give a bit better understanding of physics behind.
    BR
    MilosBog
    Be careful about reading health books. You may die of a misprint.

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