Greetings,

Suppose there is a requirement for only 8 hours to supply steam at a specific rate, lets say 100 kg/hr, at 200 DegC, 15 bar(a) Pressure. Available water is at 30 DegC, 1 bar(a).

I know how to calculate the pump work to pump the water from 1 bar(a) to 15 bar(a) and then the heat required would be flow rate multiplied by enthalpy change. This is pretty straight forward and something that I can digest.

But if someone wishes to do this only with heating, in a closed chamber, is it possible? Provide heat to 800 kgs of water at once until it reaches the required conditions, before the supply time, and start supplying from the vessel 100 kgs, each hour.

If yes, It is something that I cannot imagine/visualize. I thing the process will be isochoric, but what will happen if I simply provide heat to a closed vessel? Will pressure increase first and temperature later, or the other way around? Or both will increase simultaneously, if so where will they stop, if a pressure escape valve is attached of 15 bar? I assume the steam will stop at the saturation temperature of 15 bar 198 DegC.

In which of the two scenarios will less energy be consumed? It would be nice to have some clarity in this matter. Thanks.