SteamTab Duo Functions

The SteamTab Duo add-in package is based on a set of 19 core functions that together calculate over 30 thermodynamic and transport properties of steam. You can use these functions directly in your spreadsheet or you can use SteamTab Duo’s easy-to-use dialog boxes to automatically generate the appropriate function call with the correct arguments.

SteamTab Duo functions are divided into three categories:

1. Functions for saturated vapor, liquid or two-phase properties (2 functions)
   These two functions calculate vapor, liquid and two-phase properties from the triple point up to the critical point. You can choose either temperature or pressure as the independent variable.
2. Functions for superheated vapor or subcooled liquid properties (9 functions)
   The functions in this category provide you with a rich set of tools for conducting several constant-property processes. Depending on the choice of independent variables, you can model isentropic, isenthalpic, constant volume, or constant internal energy processes.
3. Functions for constant steam properties (8 functions)
   The 8 functions in this category give you access to fundamental steam properties that are not functions of temperature or pressure, such as, molecular weight, critical properties, and triple point properties.

The following table gives a quick overview of these functions and their calling sequence.

The SteamTab Duo functions return the requested property in either Metric/SI or English units. The thermodynamic and transport properties of steam and the units in which they are available is shown in the following table.