Question-and-Answer Resource for the Building Energy Modeling Community
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Some additional practical items to consider that you may already know, but am noting for others are some sizing info, demand charge time frame and any redundancy you may be able to remove to reduce first cost.
You want to size the tank so the chillers (i'm assuming you're storing chilled water) don't run during peak hours. in very large systems (2+ million gallons [8M liter]) you may not be able to achieve this.
You need to size the tank for 10% additional capacity to account for themocline between the warm top layer and cold bottom layer of CHW.
Confirm your utility rate structure does in fact charge demand over a certain time period. I just finished an analysis for a 5M gallon CHW storage tank, which reduced the day time peak by 3,000 kW. However that 3,000 kW just came online later and i saved almost nothing on demand charges because the utility didn't care what time of day the peak demand occurs.
If you have multiple chillers, say 3 chillers sized for 500 tons with a building peak load of 1,000 tons. You may be able to remove the redundant chiller if your storage tank can produce 500 tons of cooling. That savings should help reduce your system cost.
Hope that helps.
