HTRI has a databank to estimate physical properties for fluid streams. However, ASPEN can provide more accurate result. This article provides a method to get physical properties from ASPEN.

1. Open the ASPEN model containing the heat exchangers. select Data > Properties > Prop-Sets and create a new set containing the following properties:- CPMX (specific heat capacity of a mixture in kJ/kg-K), MUMX (viscosity of a mixture in cP), KMX (thermal conductivity of a mixture in W/m-K), RHOMX (density of a mixture in kg/m3), HMX (enthalpy of a mixture in kJ/kg) and MASSVFRA (mass vapour fraction). On the Qualifiers tab, select Vapour and Liquid from the Phase drop-down lists in the first two columns.

2. Next select Input for the heat exchanger and click on Hcurves. Select Temperature as the independent variable. 10 data points should be enough but use more if you'd prefer smaller temperature increments. Under the Additional Properties tab, select the Physical Property set you created.

3. Run the ASPEN model and save the results.

4. Start the Aspen Plus Simulation Engine (Start > Programs > Aspentech > Aspen Engineering Suite > Aspen Plus 12.1 > Aspen Plus Simulation Engine).

5. Use dos command to enter the directory where ASPEN model is saved. (to avoid it, you can copy the aspen .bkp file to above folder.
6. Type the command HTXINT <filename> and press Enter.

7. Type in HTRI and press Enter.

8. Type in SI and press Enter.

9. Enter any prefered filename. It will be the name of the .dat file created for opening in HTRI. If the model has multiple heat exchangers, select the one concerned from the list given, along with the appropriate heat curve.

10. Follow the screen prompts.

11. Open the base HTRI model that you intend to use. Select File > Open Case and open the .dat file you have just created. A blank process page should appear containing the generated process fluid properties. Drag the T&P information from the hot/cold fluid properties tab into the corresponding tab on your base model.

Done! The HTRI is using ASPEN properties now.