8 replies to this topic

[Andres Valencia Michaud]

Hello everyone!
My problem is not simple (for me at least). To make it easier, let's say it's a heat exchanger which I need to simulate and rate. I've got all old data for it but my problem is I cannot make it converge...
The hot fluid runs through tubes (H2 ~ 75%, C1 ~ 12%, G.O ~ 5,8% and others in volume) at 242ºC, 9930 KPa while the cold fluid runs through shell (Diesel, Kerosene, Hvy. Naphtha, Light Naphtha, unconverted gasoil, H2 etc) at 74ºC, 11400 KPa. Both streams exchange heat, condense and evaporate at the same time. I made the simulation but HTFS-TASC keeps telling me it has errors because it wasn't given the dynamic viscosity of the inlet streams (obviously, this is because both streams are non-homogenous)so I can't rate it. I also did some other simulations but with simpler fluids (for my problem I used their distillation curves, but for the latter I used 4 fluids which mixed gave a vapor/liquid mix like my earlier problem)
and they all converged... why my problem can't???
HELP!

I've attached a hysys 2006 simulation file.

Attached Files

•  C1201.zip   147.82KB   139 downloads

[Zauberberg]

You've setup the case in HYSYS as exchanger design - it's not possible for HYSYS to give you actual 'simulation' results. You see that both outlet temperatures from the exchanger are not known.

I would suggest you to start HTFS-TASC application (not within HYSYS) and import stream properties from HYSYS simulation case. Then, within HTFS application, choose "simulation", define the exchanger geometry and run the case. HTFS will try to predict outlet temperatures for both fluids. It works in my case.

[Andres Valencia Michaud]

You've setup the case in HYSYS as exchanger design - it's not possible for HYSYS to give you actual 'simulation' results. You see that both outlet temperatures from the exchanger are not known.

I would suggest you to start HTFS-TASC application (not within HYSYS) and import stream properties from HYSYS simulation case. Then, within HTFS application, choose "simulation", define the exchanger geometry and run the case. HTFS will try to predict outlet temperatures for both fluids. It works in my case.

Do you mind telling me what are you talking about?? (I didn't know HTFS could actually work outside HYSYS). All other ratings I've done so far in HTFS have worked fine... as you have already said, both outlet temps and pressure are unknown so HTFS does calculate them. The only problem I've found so far is this particular simulation!
I feel terribly confused!

[Zauberberg]

See attached. HTFS must be installed as an application in order to be available in HYSYS as well.
I can't remember seeing it only in HYSYS and not available as a separate module.

Attached Files

•  Program.JPG   148.71KB   58 downloads

[Andres Valencia Michaud]

See attached. HTFS must be installed as an application in order to be available in HYSYS as well.
I can't remember seeing it only in HYSYS and not available as a separate module.

Thank you very much!
The problem was, for some weird reason, I don't have ASPEN folders in "My Programs", but I did find HTFS+ in the installation folder. I'm going to take a look at it. It looks quite like HTRI.

[Andres Valencia Michaud]

See attached. HTFS must be installed as an application in order to be available in HYSYS as well.
I can't remember seeing it only in HYSYS and not available as a separate module.

Thank you a lot. All my worries are gone now... I'm in the right track now. All your advices were of real help.

[Padmakar Katre]

You've setup the case in HYSYS as exchanger design - it's not possible for HYSYS to give you actual 'simulation' results. You see that both outlet temperatures from the exchanger are not known.

I would suggest you to start HTFS-TASC application (not within HYSYS) and import stream properties from HYSYS simulation case. Then, within HTFS application, choose "simulation", define the exchanger geometry and run the case. HTFS will try to predict outlet temperatures for both fluids. It works in my case.

Do you mind telling me what are you talking about?? (I didn't know HTFS could actually work outside HYSYS). All other ratings I've done so far in HTFS have worked fine... as you have already said, both outlet temps and pressure are unknown so HTFS does calculate them. The only problem I've found so far is this particular simulation!
I feel terribly confused!

Dear,
Its always easy and friendly on working with HTFS simulation/design/rating by importing an exchanger from converged Hysys simulation file and then exporting or manually feed the HTFS output reasults into Hysys.

[haih5]

I'm a student and I'm going teach myself HTFS. Could anyone give me HTFS Tutorial files, i can't download it on INTERNET. Thank you very much.

[jcazenave]

Hi

it seems that i am a bit late but here are some extra info.

With the recent versions, you should have a Tasc+ or Shell&Tube utility. This allows you to design an HX from within HYSYS using the HTFS calcultions.

As Padmakar said, it is easy to use the Import function from the stand alone HTFS. (it is in the file menu) This will get the process and properties from a HX, heater direclty from the HYSYS case. You can then design the exchanger.

When you are happy with the design, you can use the function "Update file with geometry" under the Run Menu. This will put the calculated geometry as input into the file and change the mode into rating. You can save this file.

Then in HYSYS you can use the Tasc+ (Shell&tube) method for your HX in HYSYS, if you go to the last tab there is an import button. Import the geometry that you saved, HYSYS is now using Tasc+and the geometry to calculate Duty/pressure drop of the HX.

Sorry for the lengthy post, but I hope it helps.

Cheers

PS just seen the dates... sorry

Edited by jcazenave, 24 February 2010 - 01:12 PM.