4 replies to this topic

[SAprocessGD]

Hey,

I just have a question regarding pulling properties from HYSYS.

I am required to pull the Lower Heating Value (LHV) of various gas streams from the HYSYS property tab. For some gas streams (with very common components) I am able to see the LHV in the properties tab of that stream, while other gas streams (with some uncommon components) I can not see the LHV in the properties tab of the stream (note all the components in the gas stream can burn).

However, I can see the LHV when I do the following method.

1. Right click on the stream and select show table
2. Right click on table and Select View Properties
3. Select Add Variable
4. Under variable cloumn, Click Calculations
5. Under variable specification cloumn, Click LHV (right column)

Then in the table shown, the LHV is calculated.

So my question is if HYSYS can determine the LHV (due to calculation as mentioned above), why does it not show up in the stream properties?

I hope this is clear, if anyone has any questions, feel free to ask and I'll try to clear them up.

[sheiko]

Could you please name the components for which you cannot see the LHV property by default?

Edited by sheiko, 07 April 2011 - 08:25 PM.

[SAprocessGD]

[size="2"]N2, [/size]CO2, H2, H2S, C1, C2, C3, i-C4, n-C4, i-Pentane, n-Pentane,[size="2"]n-Hexane, [/size]n-Heptane, n-Octane, H2O, E-Mercaptan, COS, Thiophene, M-Mercaptan, CO, Ammonia, Ethylene, Propene, 1-Butene, 1-Pentene, 1-Hexene, Benzene.

Here are the main components of the stream (some of the compositions are extremely small) but I included them anyways. Thanks.

Edited by SAprocessGD, 08 April 2011 - 11:19 AM.

[process.eng88]

I know how to obtain LHV values from HYSYS but I can't figure out how to obtain them from ASPEN PLUS.

I hope someone can explain me how to obtain the the LHV values from ASPEN PLUS.

[hshethna]

Once you do show table you need to insert variable. There will be an option called calculator which when you select you will have suboptions for lhv and hhv

In v7.2 there is option for mole, mass and volume basis - ideally for gas you should choose mole basis and chose units of BTU/scf