Cooling Tonage ??

650L ≈ 650kg.

From steam tables,

h_f80degC - h_f20degC = 251kj/kg.

Total cooling needed = 251kJj/kg x 650kg = 163150kJ divided by 20min ≈ 160kW.

Convert that to tons-fridge and "Robert is your mother's brother".

The sizing of the chiller needed is best entrusted to a specialised company with the intent of securing a purchase order.

About 37.8, call it 40 tons of refrigeration. The pump will circulate ~120 gpm; piping and clearances in the jacket will need to be sized accordingly. If it is only the one tank, no control valve will be needed.

That said, I'm not sure the jacketed area can be large enough to accomplish this.

<...not sure the jacketed area can be large enough to accomplish this...>

Absolutely. The proposition is a non-starter.

Rethink your 20 minute criteria for cooling.

Unreasonably quick temperature demands made by unreasonable managers causes huge capital expenses......which, of course, get blamed on the engineer

Yes, differential equations do become useful.

I also wonder about freezing consuming some of the energy here in this rapid cool down. With an insufficient surface area, such a large volume of water to cool and this absurdly short time period to cool this. I know the OP states a 7~8C cooling water will be used but what cools this water?

Unlike many economic "laws", the laws of Physics and Mathematics cannot be waived for a business venture.

I suggest you size your chilling capacity to match your "on demand" process requirements, rather than chilling and storing your entire capacity, you'll save more money that way

GA for a good Process Rethink. Chill before use means that the contents can remain bateria-free until there is demand, and the low temperature water becoming available in seconds. Although the forum does not know the Process use of the water at this time (and why would it given a Mechanical Engineering posting? [rhetorical question - NNTR]), it is being kept at 80degC for a similar reason.

One wonders how the jacket services are being arranged with the proposal for a both a heating medium and chilled water to be available in the same jacket. Perhaps there is a vent and an air inlet to blow the terminating service back down its return main? So long as the treated chilled water doesn't go back down a steam condensate return line then maybe all will be well. Of course, the preferable chill-on-demand solution overcomes that particular problem.

dear u haven't provided on what flow you are circulating chilled water (7-8) from your 650 ltr jacket

without knowing chilled water circulation flow we can not assume Refrigeration TR capcity

If you can use water cooling in place of chilled water to cool from 80 C to about 40 C, this will save over 50% of energy. For further cooling up to 20 C, you can use chilled water. Of course, this way it will take more time to achieve the desired temperature. But this will save a lot of energy.

The total energy to be removed from the stored water in the original post concept is independent of the method of cooling.

The energy required to do it would change, though.

I agree, my view is to use room temperature water in place of chilled water to the extent possible to save precious electrical energy required for chilling unless the time factor is critical.

if you are asking how much TR your 650 ltr tank will use to cool 80 C temp to 20 C in 20 minutes

from your existing chiller you are circulating chilled water of 7-8 C at 1000 l/hr flow from tank jacket

you might get jacket leaving chilled water temperature near about 47

your DT will become 40, chilled water circulation is 1 m3/hr, so you will get 13.22 TR/Hr

here you want to do the same in 20 minutes so Total refrigeration TR you will needed is 13.22 x 3 = 39.68

from above mentioned condition you can assume how much TR your 650 ltr consuming for refrigeration from your existing chiller system

if you are planning to buy a new portable chiller you need to go for 50-55 (considered other heat losses ) TR capcity with assesories of flowing chilled water at 1m3/hr

A chiller tonage of 392 or 440 Hz is the most musical.

Sounds like a G A to me!