A steam boiler has a volume of 4 m3. The boiler initially contains 3 m3 of liquid water and 1 m3 of steam in equilibrium at 0.1 MPa. The boiler is turned on so that heat is transferred to the water and steam contained inside. For some reason, the boiler inlet and outlet valves remained closed. The safety valve opens when the pressure reaches 5 MPa. What heat transfer has taken place when the valve opens?

Answer should be : Q = 2 111 501 kJ