4 replies to this topic

[Andalus Knight]

hi all ,

 

could any one please give me simple notes about simulating the heat exchanger in hysys

I'm always facing a problem with heat exchangers

 

i feel something wrong
 

i'd appreciate ur help

 

best regards,

elgenedy
 

Attached Files

•  1.JPG   45.2KB   58 downloads
•  2.JPG   47.08KB   48 downloads

Edited by elgenedy, 23 May 2013 - 02:11 AM.

[thorium90]

Just looking at those two screenshots is impossible to tell much. You might want to provide more information... Perhaps show what is on the other tabs?

[Robert Montoya]

hi all ,

 

could any one please give me simple notes about simulating the heat exchanger in hysys

I'm always facing a problem with heat exchangers

 

i feel something wrong
 

i'd appreciate ur help

 

best regards,

elgenedy
 

 

Hi this is a typical problem. You must increse the pass number for tube side  due the low FT.

 Hysys does not design heat exchanger, however with 7.3 & 8.0 version you can do it using HTFS.

[Alexsandres]

Robert Montoya is right,

 

You should change the pass number for the tube, flowrate configuration (co-current/counter current), or even change the shell type

[thorium90]

elgenedy,

 

Although Robert Montoya and Alexsandres's reply will solve your problem initially, I frankly tell you that you have a more serious but common problem.

 

You have no idea what is the purpose of a simulation and how to make a good simulation. Plugging in random values into a magic box that produces miraculous answers is not called a simulation. Sure, changing the pass number or shell type (cocurrent/countercurrent is completely irrelevant here, Alexsandres) will solve your problem. But you must ask yourself, why are you changing these?

 

There are two broad purposes for a simulation of your exchanger. The first is known as designing. It is when you do not have the equipment and you want to find out the specifications of the equipment. Tools like EDR help to perform this. One then uses hysys to create an exchanger with the specifications generated by EDR and therefore simulate the exchanger.

 

The second is known as rating. It is when you already have the exchanger installed in your plant and you want to check how well it should have been performing based on the design. You would input the specifications of the installed exchanger and its parameters into hysys and check if what is calculated is similar to what you get in reality.

 

It is a very common mistake among students doing the design to not perform any preparatory calculations and simply rely on the error messages to tell them what they should do next. As well as relying on the absence of error messages to tell them they have completed their task. This is wrong.

 

Take the example in the following thread.

http://www.cheresour...to-chill-water/

 

I would suggest that you read up your heat transfer texts and other articles posted on this forum on designing heat exchangers before attempting to make a simulation. Find out stuff like what type of exchanger you should use and why; a BEU, AES, etc. Don't just randomly change stuff just so the error messages don't appear. No error messages does not mean a good simulation.

Attached Files

•  Effectively design shell n tube exchanger.pdf   241.91KB   181 downloads

Edited by thorium90, 27 May 2013 - 11:49 PM.