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TBFTL
03-05-2006, 05:24 PM
Can anybody give me an idea of how you size chillers for ice rinks?

Is there a general rule of thumb? or is it a bit more complicated than that.

Cheers

NoNickName
03-05-2006, 06:52 PM
P = Q x Cp x dT

Cooling capacity required is equal to the brine flow times the thermal coefficient of the medium times the deltaT of the medium to be cooled.
The energy required is equal to the water volume times the thermal coefficient of the medium times the deltaT of the water to be cooled.

Ideally, to freeze 1 dm3/s of water from 25C to zero it takes 100 kW of cooling capacity, to which heat gains from the rink arena must be added (windows, doors, clapping and shouting spectators).
Tipically a person would dissipate around 200 to 300W, partily as sensible heat, but especially latent heat that will condensate and freeze on the skating surface.

A 10000 person ice rink with a 80x40 meter surface, 0.30m deep would require 1000 m3 of water let's say to be frozen in 24 hours, that gives 11.57 dm3/s, or 1150kW plus 200kW of spectators heat gain plus architecture heat gains and lightings

Josip
04-05-2006, 11:46 AM
P = Q x Cp x dT

Cooling capacity required is equal to the brine flow times the thermal coefficient of the medium times the deltaT of the medium to be cooled.
The energy required is equal to the water volume times the thermal coefficient of the medium times the deltaT of the water to be cooled.

Ideally, to freeze 1 dm3/s of water from 25C to zero it takes 100 kW of cooling capacity, to which heat gains from the rink arena must be added (windows, doors, clapping and shouting spectators).
Tipically a person would dissipate around 200 to 300W, partily as sensible heat, but especially latent heat that will condensate and freeze on the skating surface.

A 10000 person ice rink with a 80x40 meter surface, 0.30m deep would require 1000 m3 of water let's say to be frozen in 24 hours, that gives 11.57 dm3/s, or 1150kW plus 200kW of spectators heat gain plus architecture heat gains and lightings

Hello NoNickName,

can you, please, explain why you use 0.30m (30 cm) of water, ussualy we do not put more then 4-6 cm of water.

At one hockey ice rink here in Zagreb we make ice with Stal-mini (Q=400kW) with motor of 132 kw at -10C/35C. Only in the begining of season 2-3 days that compressor runs at 100% but later on about 30-60%. Ice tchikness is about 5-6 cm.

Best regards,

Josip

NoNickName
04-05-2006, 11:51 AM
Details of each installation may vary. For example, curling rinks are much thicker and stiffer.
If volume of water is 1/5 and time is elapsed 3x, cooling capacity is adjusted accordingly.
Any plant is different, and any customer is fussy in different ways

Josip
04-05-2006, 12:43 PM
Details of each installation may vary. For example, curling rinks are much thicker and stiffer.
If volume of water is 1/5 and time is elapsed 3x, cooling capacity is adjusted accordingly.
Any plant is different, and any customer is fussy in different ways

Hello NoNickName,

anyhow cannot see any reason to freeze 1000m3 of water instead of (in my case 60m x 30m x 0,05m) =90m3 or in your case (80m x 40m x 0,05m) =160m3 what is more then 6 times less.

What is construction of that ice rink?
pipes/concrete/ice or something else

How you can keep frozen that ice block 80m x 40m x 0.30m = 960m3 when temp on open side is about 10-18C depending on arena.

I'm courious because never ever seen something like that. Post some more material about, please, becuse I believe it will be interesting also for other guys.

Best regards,

Josip:)

NoNickName
04-05-2006, 01:21 PM
80x40x0.3 = 960m3.
It's easier to keep cold a huge amount of ice, because of inertia. Unfortunately I don't have any material, because it's an installation of a customer of mine, which I don't even know where it is (my customer who is the installer is austrian, I suppose the ice rink is in Austria).

Johnny Rod
05-05-2006, 10:16 AM
Does the thickness of the ice matter? If you've got a bit of ice it'll absorb heat depending on its surroundings, the ice will be at the same temperature regardless of how much of it you have?

NoNickName
05-05-2006, 11:07 AM
Ice has a low thermal transfer, so when ice forms around the brine tubing, the ice formation will progressively slow down.