WSP(R) Sample

Throttle process calculation

Annotation

In this file you may found the example of usage functions for calculating properties of water and steam for calculating process of throttle.

About WSP

WSP is a certified program for calculating properties of water and steam.
Additional information about WSP given in it's documentation.
New versions and online documentation available in the www-site of the WSP: http://twt.mpei.ac.ru/orlov/WSP

Import units definitions and WSP dimensions functions

Source data

Find the parameters of steam at the end of throttle process from parameters: pressure p0 and temperature t0 to pressure p1 without working fluid heat exchange.

Values:

Solution #1 (with functions of the WSP available in demo-version)

1. Parameters in initial point

• specific enthalpy:

• specific entropy:

2. Find a temperature at the end of process

For finding the temperature will use the Mathcad solver block: Given ... Find.
The source equation for the Given ... Find block will be the fact that the specific enthalpy at the start of process equal the specific enthalpy at the end of process.

The initial value for the Given ... Find block:

3. Parameters at the end of process

• specific enthalpy:

• specific entropy:

4. Create the graph of process in the h-s diagramm

Solution #2 (with the functions for calculating processes of expansion/compression)

1. Parameters in initial point

• specific enthalpy:

• specific entropy:

2. Parameters at the end of process

For determining of the parameters will use the functions of the WSP for calculating processes of expansion/compression.
These functions require a value of internal relative efficience. For the processes of throttle without heat exchange the value is:

• temperature:

• specific enthalpy:

• specific entropy:

3. Create the graph of process in the h-s diagramm

Comparison of the results

1. Temperature

2. Specific enthalpy

3. Specific entropy