# 02.16 Unsteady State Open Systems

### Steam Tank Filling

Energy Balance: Filling a Tank (LearnChemE.com, 5min) determine the final properties of a tank to which steam is added.

Comprehension Questions:

1. An empty tank is filled by opening a valve and allowing steam at 300°C and 8MPa to flow into it until the pressure equalizes. Estimate the final temperature (°C).

2. An empty tank is filled by opening a valve and allowing steam at 350°C and 8MPa to flow into it until the pressure equalizes. Estimate the final temperature (°C).

3. An empty tank is filled by opening a valve and allowing steam at 300°C and 6MPa to flow into it until the pressure equalizes. Estimate the final temperature (°C).

### Evaporative Cooling

Evaporative Cooling Energy Balance (LearnChemE.com, 6min) apply the energy balance to liquid water that is evaporating and undergoing evaporative cooling.

### Steam Tank Filling (Unevacuated)

Tank filling: Steam, Unevacuated (uakron.edu, 15min) Unsteady state problems are relatively easy to solve for ideal gases, especially when the tank is empty to begin. The solution process becomes more difficult using steam with some H2O already in the vessel. This demonstration shows how to adapt to the new situation. The point is to learn the manner of adapting, not so much answer for this particular problem. You may not be filling many tanks with steam in your life, but you will certainly be adapting to new situations. The steps of analysis, identifying pieces of the puzzle, and putting them together are key components of any such adaptation.