I would like to start a forum on modeling ice storage.
I have had many problems when modeling an ice storage system in eQUEST.
I first crate a thermal storage tank and attach it to the chilled water
loop. Then I set the operating temperatures and attach a charging
schedule. I also input the Capacity Ratio, (When CAPACITY is defaulted,
accepts a numeric value that acts as a multiplier on the loop's design
hourly load. The default is one hour's load) since I want the tank to
discharge for 6 hours I input a ratio of 6.
My next step is to create equipment controls for the chilled water loop.
The following image is of the Load Range control:
The results of this shows a realistic cost savings but the energy
consumption does not make sense. The cooling consumption decreases
significantly (I would have expected it to slightly increase) and the
heating energy consumption is affected (the heating energy consumption
should not be effected by the ice storage tank).
Since eQUEST's results do not appear to be correct, I use an excel
spreadsheet from a Thermal Storage manufacturer to calculate the
savings. Since there should be a minimal energy consumption difference,
I simply subtract the savings from the electrical cost. This method
works fine except for the fact that I cannot seem to force eQUEST to
subtract the savings from the electric consumption. If anyone knows how
to subtract cost (and label it as "Ice Storage Savings") using eQUEST
please respond to this email!
Any help is appreciated.
Otto Schwieterman