My question is about a tank filled with some liquid (properties of the liquid are known and can be considered constant. Specific heat equals 1.5 kJ/(kg.K)). The initial temperature of the liquid in the tank is 90 ºC. Now imagine that 2000 L/h of this liquid are recirculating, but before returning to the tank they are heated somehow (doesn't matter how) until they reach 240 ºC (assume it remains a liquid at this temperature).
How can I estimate how much time it would take before the tank temperature reaches 230 ºC. The liquid volume on the tank is constant and equal to 10000 L.
It's kind of an open problem (the values are only hypothetical so that the problem can be implement on Excel). How should I start analyzing it? What equations should I be looking for?