Chilled Water Ton/Hours Calculation

[Pescadore]

Hello Everyone,

I need to calculate ton/hours in a 180,000 gallon thermal storage tank. Can anyone help me with this? I have tank level and tank temp as system variables. Do I need to know system GPM also? Thank you.

 

[DRWeig]

Is there any freezing / thawing going on?

Give us temperatures, type of fluid, etc... As many details as possible.

Good on ya,

Goober Dave

 

[ChrisConley]

System and chiller gpm would be helpful. Tank dimensions as well.

 

[Pescadore]

This is a chilled water system. There is no GPM meters currently on the system. The tank is 10 feet deep by 40 feet in diameter. The usual tank temperature is 43 degf. There is no freezing/thawing going on. Thanks for any and all help.

 

[DRWeig]

10*[π]*(40/2)^2 = 12,566 cubic feet
12,566*62.4 lbm/cu ft = 784,141 lbm
Assuming 10°F [Δ]T, that's 7,841,410 Btu in storage.

7,841,410 Btu / 12,000 Btu/h/ton = 653 ton-hours

Calculation above does not take any losses into account, nor the fact that you can't get back 100% of the energy you spent in cooling it, nor any allowance for decreasing effectiveness of heat exchangers as tank temperature rises.

Oh, and you might want to wait and see if anyone checks my work. I haven't had my coffee yet.

Good on ya,

Goober Dave