7/29/2019 Thermo-013H PT Envelope

1/6

2012 Aspen Technology, Inc. All rights reserved

Revised: November 26, 2012

Generate PT Envelopewith Aspen HYSYS

Using Aspen HYSYS V8.0

7/29/2019 Thermo-013H PT Envelope

2/6

2012 Aspen Technology, Inc. All rights reserved | 2

Objectives

Learn how to generate the phase envelope of a mixture.

Learn how to interpret the phase envelope of a mixture.

7/29/2019 Thermo-013H PT Envelope

3/6

2012 Aspen Technology, Inc. All rights reserved | 3

Background

The PT envelope for a given mixture provides the wholepicture of the phase conditions for the mixture.

It is very important to know the phase conditions of a

mixture at a given temperature and pressure. The phase conditions of a fluid in a heat exchanger have an impact on

the heat transfer rate of the heat exchanger.

Formation of bubbles (vapor phase) in the inlet stream of a pump canbe very damaging to the pump.

The phase conditions of the fluid in a pipe can impact pipeline

calculations.

7/29/2019 Thermo-013H PT Envelope

4/6

2012 Aspen Technology, Inc. All rights reserved | 4

Key Teaching Points

The PT envelope can be easily generated for a given mixture.

The portion of the curve that corresponds to the vapor fractionof 0.0 is the bubble point curve.

The portion of the curve that corresponds to the vapor fractionof 1.0 is the dew point curve.

Curves that correspond to other values of vapor fractions canalso be generated.

7/29/2019 Thermo-013H PT Envelope

5/6

2012 Aspen Technology, Inc. All rights reserved | 5

Recommended Further Exercises

Generate the PT envelope of air (78.5% N2 and 21.5% O2on the StdVol basis). What is its phase condition at 25bars and -160 C?

7/29/2019 Thermo-013H PT Envelope

6/6

2012 Aspen Technology, Inc. All rights reserved | 6

Copyright

Copyright 2012 by Aspen Technology, Inc. (AspenTech). Allrights reserved. This work may not be reproduced or distributedin any form or by any means without the prior written consent ofAspenTech. ASPENTECH MAKES NO WARRANTY ORREPRESENTATION, EITHER EXPRESSED OR IMPLIED, WITHRESPECT TO THIS WORK and assumes no liability for any errors or

omissions. In no event will AspenTech be liable to you fordamages, including any loss of profits, lost savings, or otherincidental or consequential damages arising out of the use of theinformation contained in, or the digital files supplied with or foruse with, this work. This work and its contents are provided foreducational purposes only.

AspenTech, aspenONE, and the Aspen leaf logo, aretrademarks of Aspen Technology, Inc.. Brands and product namesmentioned in this documentation are trademarks or service marksof their respective companies.