7 replies to this topic

[process_persia]

Dears,

I am trying to simulate a heat exchanger which is shown as 18E002 on the attached figure. the tube side is process gas (N2, H2, CO2 Water, CH4, C2H4, C2H6, C3H6 and C3H8) shell side is a refrigerant (Ammonia, water). As you can see in the PFD, there are two streams leaving the shell (a vapor and a bleed stream of ammonia). I would like to know how I can simulate this heat exchanger in which different streams with different properties are leaving the shell in HTRI . the Heat exchanger in TEMA BKU type by the way.other info are as follows:

1- Tube length: 6000 mm
2- Number of tubes: 3256
3- Tube O.D and wall thickness: 19.05 * 2.11 mm
4- Area: 1250 m2
5- Tube layout/ pitch: 90 / 28.575mm
6- 2 passes on tube side

Thnaks in advance

Attached Files

•  18E002_Treated Gas Cooler.xlsx   161.17KB   91 downloads

[chemsac2]

Process_persia,

In "Nozzle" menu in HTRI, there is an option for liquid outlet. Specify your liquid nozzle size (Bleed stream) in that field as actual ID. HTRI does not have provision for specifying nominal bore and schedule for liquid outlet.

Also check location of liquid outlet nozzle in "Nozzle orientation" sheet.

Your duty specification and ammonia flowrate would decide how much of your inlet stream is vaporized and how much leaves from liquid outlet.

Hope it helps.

Regards,

Sachin

Edited by chemsac2, 20 July 2010 - 05:33 AM.

[process_persia]

Thank you Chemsac for your answer...it did help...by the way, I came up with another question. what is exactly the role of multiplier in the last row of process tab?

Best,

[Propacket]

process_persia ,

Besides specifying the liquid nozzle, you also need to specify outlet vapour rate & outlet liquid rate in terms of outlet vapour fraction.

[Padmakar Katre]

Dear,
Are you using HTRI in simulation mode and how are these results? I will suggest you to use a simulator like Hysys, Aspen Plus to generate the data i.e. heat curves and terminal conditions and put it into HTRI and with the inputs mentioned above you can rate the exchanger.
The multiplier in the last tab is the design margin you want to keep. 1.1 means 10% margin so the exchanger will be sized(in case new) or rated(existing) for 110%.

[mehul]

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[process_persia]

Dear Padmakar S Katre and Mehul,

Thank you for your valuable hints, I think HTRIs Thermodynamic is still weak compared to other process simulators so your idea of using data from other simulators is quite right.

Thanks again

[jcazenave]

If thermo is important AspenTech EDR (HTFS) offers the same properties package than Aspen+ or HYSYS simulator. This might be a good alternative.