4 replies to this topic

[jprocess]

Dear All,
I shouuld be grateful if you would answer to my questions regarding to Heat Exchanger design packages like Aspen B-jac,Htfs,Htri,and etc.
I have not any engineering view about their design and optimisation algorithm.For example using B-jac first i prepare flow and temperature information in design mode and run the program.
The package results show that the offered design will satisfy the temperature requirments but when i swith to the rating and simulation mode and run the simulator the resulting temperatures are different!
Also where can i find case studies and examples regarding to these packages?
Thanks in advance.
Best of luck.

[Zauberberg]

Aspen Engineering Suite (and B-JAC is a part of it) includes a special CD titled "Documentation", where all tutorials are available in digital format - this is from what I have heard about AES software. You can check with the software supplier if this is true.

Concerning the temperature differences you retrieve from "design" and "rating" modes of simulation is quite logical. For example, if you keep U-values the same (unchanged when switching between design and rating - which is a common mistake), the simulator will come up with different heat transfer rates - much more efficient - compared to the real situation. Be sure to include all factors when evaluating equipment performance: "rating" is supposed to give you the results of actual performance and heat transfer rates, not to calculate heat balance for design parameters.

[Sadananda Konchady]

Generally in thermal design of heat exchangers, the results given in the Design mode are preliminary and not the final ones used in practice.

Usually, the rating mode may be used to fine tune the design obtained in the design mode according to other constraints and the surface margin is then verified.

The simulation mode can be used to predict the output conditions from an existing heat exchanger geometry for specified fluid inlet conditions on the shell side and tube side.

Hope this clarifies the use of the modes which are generally available in commercial
thermal design softwares.

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escape

[process equipment]

hi all,
can you also use fluent to design heat exchangers .. would the results be different and more accurate then htri,htfs . I've never use htri ? BTW i was wondering if there are some examples, assigments on cfd modelling of heat transfer equipments like heatexchangers, burners, heaters etc.

Cheers

PE

[Zauberberg]

Hello PE,

Have you tried to find something at Fluent website? I was curious to find articles related to computational fluid dynamics, and I visited Fluent on the web. There are plenty of information - articles written by software users. Almost every field of industry is covered; very roughly, of course.

http://www.fluent.co...tions/articles/

I have never used software like Fluent, though. If you got stucked with particular problem definition, maybe the company support team could be of help to you (I saw there is a CFD Learning Center, available only for Fluent customers).

http://www.fluent.co...pport/index.htm

If you are persistent enough, Google will come up with plenty of interesting results.
Best regards, friend.