5 replies to this topic

[Phani Kanth]

Hi all,

I'm facing the problem with hysys,when try to get the steam data by using ASTM Steam Property Package.These data doesn't match with Standard Steam Tables Data.

So,kindly suggest alternativies for this problem.


Regards,
Phani Kanth

[pavanayi]

Phani Kanth,

Which data do you have problem with? Is it enthalpy values?

[Phani Kanth]

@pavanayi,


Thank u for reply,
Yes problem with enthalapy values.

[pavanayi]

Phani Kanth,

The reference state for enthalpy calculation for Hysys is different from that of steam tables. That is why the enthalpy values are different in Hysys / steam tables/ any other different source.

But normally you are only concerned with ΔH (change in enthalpy) and not absolute values. For all calculations, you need to calculate change in enthalpy between two conditions.

Take two conditions for steam (ex, condition1: 2 bar a, 150°C and condition 2: 10 bar a saturated), and calculate ΔH between the conditions using both Hysys values and steam table values. You will find your answer there.

Hope that helped.

[Robert Montoya]

reference valueare differentbetween the tablesand the simulator,however the delta are equal.

[sheiko]

Phani,

I agree with pavayani but to confirm this, could you please give us an example with:

- An enthalpy value of saturated steam from Hysys at a given pressure P
- An enthalpy value of saturated steam from ASTM tables at same P
- The latent heat of vaporization at P (should be the same in both sources)

Edited by sheiko, 12 March 2012 - 10:08 PM.