I am trying to build a spreadsheet to adjust a certain flow rate to maintain
a specified tank volume. For instance, I want to maintain a tank volume of
234000gal. I have a water demand that varies from 1400-2400gal/min (gpm),
with an average of 1600gpm. The supply flow rate can range from
1200-1800gpm. I want to be able to adjust the supply flow rate to maintain
the tank volume. The demand flow rate is a set of values based on historical
data. When the tank volume is less than 234000gal, the supply flow rate will
max out at 1800. When the the tank volume is less than 234000gal, the supply
flow rate will decrease. I can get the solver to work for a single set of
data, but I want to use the solver to calculate a cummulative tank volume as
the demand and supply flow rates change. I appreciate an help that you can
offer.