simulating a heat exchanger on the Hysys 2

If you can explain your specific problem, we can probably help you out. From your question, I don't understand what exactly you are looking for. Did you read the manual yet?

Cheers,
Joerd

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

Hello,
I'm trying to simulate the heating NaOH 20% to boiling temperature with using saturated steam water (P=0.3 MPa) on shell-and-tube heat exchanger ( i need to calculate the sizing of apparatus), but on the Conditions page of the Worksheet tab of Hysys, i don't know which number need to enter. Can you please explain it for me?
Here is my work:

Hello H2Tran,

What you usually must know when designing heat exchanger, from thermohydraulic point of view, is:

1) Maximum allowable pressure drop for one or both fluids (depends on specific application).
2) Inlet and outlet conditions (p, T) of both fluids. The flow of utility fluid is calculated using heat balance equations. I'm assuming that compositions and physical parameters of both streams are known.
3) Any specific metalurgical, physical/chemical concern (fouling tendency, erosion, vibration, thermal stability etc.) - that is something that goes in further design steps.

HYSYS is not so good in heat transfer design applications. The latest version (now under the name UniSim Design - Honeywell trademark) is somewhat upgraded by certain AspenTech moduls, as I have heard. But I didn't have a chance to check it.
I hope this helps in your query.
Concerning the file you attached, please check your streams - names and stream allocation, compositions, pressures and temperatures.

First of all, check your property package. Normally, for steam, use ASME Steam or NBS Steam. With PR, double check your results with a steam table.
If you have saturated streams, it is better to have Hysys figure out the temperature. Set the vapor fraction to 0 for saturated liquids/condensate (Hysys will calculate the bubblepoint), and set it to 1 for saturated vapors/steam.
If you set the model to Exchanger Design (Design tab, Parameters page), then you don't need to specify anything on the Rating tab.

Cheers,
Joerd

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

H2Tran,

As Joerd has pointed out, choosing thermo package is one of the crucial items in process of building simulation models. Be sure not to make any mistakes or wrong assumptions.
There is one good article about common equipment/process simulation mistakes at Simsci-Esscor website, I'm sure you'll find many interesting issues.


Another interesting document (I assume you have Hysys tutorials) is available at Chemstations website:


Regards,

HYSYS is not a HX sizing software.

If you know both your shell and tube side conditions - then HYSYS will calculate the required UA.

The other way (there is one unknow (may be flowrate, Tin/out or any other) then specify UA and HYSYS will calculate the dependant.

HYSYS includes some simplified sizing algorithms where it will calculate the UA based on some parameters that you can fill in (TEMA type, nos of tubes, tube szie etc). These algs are however mainly for indication.

Best regards

Morten

Just be careful when selecting the tube material for the NaOH side!