Mr. Tersoo Abiem

greeting

the critical pint for the boiling point at the condition 373K and 101325pa. when the boiling water convert ( change in phase from water to vapor) the saturated pressure already going to increase because you have the closed vessel. so if there is a heat reject from closed vessel ( there is no insulation) in this case the water convert to steam also steam convert to water depending on the heat balance.

other wise if the vessel full insulated the boiling water convert to the vapor at saturation temperature and the vapor go to super heated steam when notes a change in saturated temperature.

otherwise ( practical method) you can instill long sight glass ( high pressure) measuring the water level.

initially you have the volume of water in the vessel, so the missing volume present vapor mass.

Dear Terso,

Apply energy balance.

Heat given per unit time = mass flow rate *( latent heat of vaporisation + thermal heat capacity of water *(373- initial temperature) + thermal heat capacity of steam * ( final temperature- 373))

you have a classical problem of energy balance as my colleague Syed told you. you need calculate the energy losses and the energy supplied to the system, the diference is used to evaporate water (the heat of phase change at the system pressure). For the increase in the pressure and temperature as a function of time remember there are in boiling water lineally dependent variables, then one of them determine the other. if the system is open then the flow resistance determine the balance between the steam leaving the system and the energy supply. if closed then you need a unsteday formulation for the energy balance.

Thank you @ Ali Dawood Salman, @ Syed Mughees Ali and @ Ruben Borrajo for your answers.