Steam Tables: Summary
Key points from this module:
- Most liquid properties (volume, enthalpy, fugacity, internal energy, entropy, and Gibbs free energy) change slowly with pressure. Thus for many problems, these properties are assumed independent of pressure.
- If any two intensive properties (temperature, pressure, volume, enthalpy, entropy, internal energy) of water are known, then a unique location can be found in the steam tables.
- The properties of water as a liquid at a given temperature and pressure can be assumed to be close to the properties at that temperature and its saturation pressure. Even when the pressure is above 5 MPa, the properties do not change much; these values can be found in the compressed liquid table.
- For liquids, internal energy and enthalpy are almost the same because the liquid volume is small, so the pressure-volume term is small.
From studying this module, you should now be able to:
- Determine a state property of water when given two other state properties (pressure, temperature, volume, internal energy, enthalpy, entropy).
- Interpolate in the steam tables (single and double interpolation).
- Explain the difference between the saturated steam tables and the super-heated steam tables.
Prepared by John L. Falconer, Department of Chemical and Biological Engineering, University of Colorado Boulder