Heating Water in a Closed Vessel
Prepared by H. Binous, I. Boukholda, and A. Bellagi

This Demonstration shows what happens to water, initially in liquid-vapor equilibrium at 300 K, if it is heated in a closed vessel with a given volume V. The heating medium is saturated steam at 520 K and the initial liquid volume fraction is Z0.

Assuming that the system is always in a vapor-liquid equilibrium, the Demonstration plots the liquid mass, vapor mass, pressure, temperature, and heat input rate Q versus time. In addition, the dynamic behaviors of the liquid and vapor volumes and the liquid volume fraction Z = vl/V  are displayed. The latter curve looks peculiar. Indeed, depending on the thermodynamic conditions, the liquid volume fraction increases upon heating instead of decreasing.
