Compressor curves with GERG 2008 in Prode 1

[drilling53]

I am evaluating compressor performances comparing results from different models in Prode Properties,
I am mainly interested to compare high-accuracy Helmholtz-energy models ( GERG 2008 ) vs. three parameter corresponding states ( Lee Kesler Plocker ) vs. virial models ( Modified BWR )
As expected there are differences but I have no idea about the errors in integration procedure (which could influence the results), Prode adopts a variant of integration procedure proposed by Huntington, I have the paper and errors should be really very small (compared with standard ASME PTC-10) can someone confirm ?

 

[PaoloPemi]

the integration procedure (to solve polytropic stages) included in PRODE Properties adopts a 5 points method and it is very accurate,
certainly more accurate than ASME PTC 10 or similar direct procedures,
numerical errors are well below those of accurate models as GERG 2008,
you can safely presume that errors are mainly from EOS

 

[Iomcube]

Can you two share some pictures of how you are using Prode to achieve your goal?

 

[PaoloPemi]

which type of problems do you wish to solve ?
for design / rating of centrifugal compressors / pumps (the procedure works with gas and vapor + liquid , for example wet gas) Prode Properties can solve single and multiple stages and calculate thermophysical properties (as I suppose can do other simulators).
The main difference (comparing Prode to other simulators) is that you solve in Excel, Python, Mathcad etc..

 

[Iomcube]

I would like to have any example of multistage compression power requirements for Cl2 (g) (single component); PD compressor. If you can share a tutorial I be very happy. The thermodynamics behind it I know; so PRODE tutorial is welcome

 

[PaoloPemi]

you can simulate a multistage compressor as a series of single stages,
you can include inter stage coolers as well (with a flash operation),
for positive displacement compressors you may wish to use a different model,

there are Excel examples for that, you may contact the vendor for details.

 

[rotw]

I have a piece of software that does exactly that too (what the OP is asking). i.e. simulating compressor performance / multi-stage machine with GERG 2008 with compression method other than ASME PTC10.

If you send out your calcs details / case condition, I can make a run for you.

 

[drilling53]

PaoloPemi,
thanks, I have verified the accuracy with the reference method discussed in the paper,
to obtain the same values (calculated with the integration method in Prode) the reference method requires hundred of small steps... and much more time,

rotw,
I calculated the values with the methods available in Prode Properties, which procedures / methods does your software use ?

 

[oilpmp]

I would suggest n-centrix tool which can plot curves based on GERG (not sure though if it is 2004 or 2008 version); you may attempt both ASME PTC10 or Huntington methods.

Another reference is a paper I would strongly suggest is available here .

 

[drilling53]

thanks for the note, as said in my previous post I have verified the results from Prode Properties with the values reported in that paper, appendix a the columns for 600-Step Numerical Integration, as I understand, Prode adopts a 5 points integration method, which I have verified to be very fast and accurate,
the paper also compares the reference method vs. 3 points integration vs. Schultz (ASME PTC-10) method and I obrained similar results with Prode,
I must agree with PaoloPemi, these mthods are very accurate.