Model of a tank, a pump and a heater that
forms an algebraic loop on the mass flow rate.
This implementation is less efficient than HeaterOpenTankRefactored.xml
because each time the integrator changes the value of T, the mass
flow rate is recomputed by solving an algebraic loop.
However, the mass flow rate does not depend on the T.
This situation is caused because the tank is modeled in a composite
actor, and hence has as an input the temperature, mass flow rate and pressure.
Therefore, the event of the integrator cause the algebraic loop solver to recompute
the solution.