Lesson 6PROPERTY DIAGRAMS AND STEAM TABLES

• DETERMINE any unknown properties for a fluid given a Mollier diagram and sufficient information to indicate the state of the fluid.

• DETERMINE any unknown properties for a fluid, given a set of steam tables and sufficient information to indicate the state of the fluid.

• DETERMINE the change in the enthalpy of a fluid as it passes through a system component, given the state of the fluid at the inlet and outlet of the component and either steam tables or a Mollier diagram.

Property Diagrams

• Pressure- Temperature (P-T) diagrams

• Pressure-Specific Volume (P-v) diagrams

• Pressure-Enthalpy (P-h) diagrams

• Enthalpy-Temperature (h-T) diagrams

• Temperature-Entropy (T-s) diagrams

• Enthalpy-Entropy (h-s) or Mollier diagrams.

Pressure- Temperature (P-T) diagram

Pressure-Specific Volume (P-v) Diagram

Pressure-Enthalpy (P-h) Diagram

Enthalpy-Temperature (h-T) Diagram

Temperature-Entropy (T-s) Diagram

Enthalpy-Entropy (h-s) or Mollier Diagram

Steam Tables

• Saturated steam tables

• Superheated steam tables

• Both sets of tables are tabulations of pressure (P), temperature (T), specific volume (v), specific enthalpy (h), and specific entropy (s)

Saturated Steam Tables

• Provide energy transfer properties of saturated water and saturated steam for temperatures from 32 to 705.47°F (the critical temperature) and for the corresponding pressure from 0.08849 to 3208.2 psi.

• Divided into two parts:– Temperature Tables – Lists properties according to

saturation temperature (Tsat)– Pressure Tables - Lists properties according to saturation

pressure (Psat).

Property Diagrams and Steam Tables Summary

• The Mollier diagram can be used to determine various properties of a fluid.

– Mollier diagram is an h versus s plot.

– Can only be used when quality is greater than 50% and for superheated steam.

– Contains a series of constant temperature, constant pressure, constant moisture content, and constant superheat lines.

Property Diagrams and Steam Tables Summary (continued)

The steam tables can be used to determine various properties of water using the following equations.

Property Diagrams and Steam Tables Summary (continued)

The change in enthalpy of a fluid as it passes through a component can be determined using a Mollier diagram on steam tables.