Water Temperatures in Tank?

[nenenene]

I appreciate if some one can help me to get the formula and calculations of water temperatures at any time while water temperature rise because of re-circulating pump (P1) 90 gpm re-circulate water between a tank and a steam-water heat exchanger that has a maximum capacity of 2300 MBtu/hr.

The maximum water volume in the tank starts with (V1) 209 US Gallons and Temperature (T1) while it goes down with its level gradually to minimum volume (V2) 136 Gallons because of Pump (P2) 60 gpm connected to the same tank withdraws water from the tank. (The two pumps P1 and P2 works at the same time).

 

Second Situation: Also I looking to get a formula and calculate water temperatures in the tank at any time as it rises while Pump P2 (60 gpm) Still runs but the re-circulating pump P1 (90) gpm stopped. Solenoid valve to the same heat exchanger enable cold water of 75 gpm with a temperature of 50 °F flows to the heat exchanger to the same tank, rises to water level from (V2) 136 Gallons to (V1) 209 Gallons and stop.

 

Thanks