A tank of volume 1.2 m^3 initially contains steam at 8 MPa and 400°C. Steam is withdrawn slowly from the tank until the pressure drops to p. Heat transfer to the tank contents maintains the temperature constant at 400°C. Neglecting all kinetic and potential energy effects and assuming specific enthalpy of the exiting steam is linear with the mass in the tank. Required:
a. Determine the heat transfer, in kJ, if p = 2 MPa.
b. Plot the heat transfer, kJ, versus p ranging from 0.5 to 8 MPa.