11 replies to this topic

[abhigarg]

Hi All,

Could you please tell me if line sizing can be done using hysys.If yes, then how can we do it.basic steps may help me....

Thanks in advance..

Abhinav

[Zauberberg]

Preliminary line sizing can be done either using pipe unit operation, or PipeSYS extension. Help files and tutorials offer the complete guidance. If you are familiar with basic concept(s) of line sizing and hydraulic calculations (you remember the guy named Darcy?) then it is absolutely trouble-free to perform such work.

Sizing process lines is one of the most simple engineering tasks, and it is a shame for all of us if we have to seek for software help - that's my opinion.

[abhigarg]

Hi,

Thanks for your reply.

Abhinav

[JoeWong]

A process engineer shall be familiar with hydraulic calculation.

Compressible and non-compressible, high pressure drop line (pressure drop more than 10% of upstream pressure), outlet pressure low pressure or near ATM, etc would significantly affect to performance of your line calculation. Then using Software is the mean to minimize your error in properties prediction, impact of the properties change, etc.

Having said that understand fundamentals of hydraulic calculation and its associate assumption and potential error, ability to assess your condition with associate equation used and understand equation used in HYSYS, etc are crucial.

[djack77494]

I'd highly recommend that you DO NOT use Hysys or any other simulator for line sizing. Far better is to be familiar with your process and to know what is and is not important to good long term operation. Are you dealing with a situation where pressure losses are very critical (e.g. vacuum systems) or one where you have "pressure to burn"? Hysys doesn't know. Do you have a corrosive or erosive fluid that experience tells you a range of acceptable velocities? Again, Hysys doesn't know. There's no substitute for knowledge of your system. If you've gotten that knowledge, then by all means use the available tools you have to help "grind out the numbers". That's all software can do. Good luck.

[Padmakar Katre]

Dear,
Yes Hysys should not be used for Line Hydraulics (Plant Piping). PipeSys will result good results in case if you are modelling a Pipe Line. For Line Hydraulics one should go for hand calculations based on the available formulas. The best way to go trough the Crane and prepare your own spreadsheet. This will be the best way of learning rather just to input the values in hsysy and get happy with the results as Hysys doesn't tell what it does inside unless you refer the equations used to perform that calculations.

[sheiko]

Sorry but i don't see why we should not use simulation softwares since they use the same basic equations (Darcy, Churchill, ...) than our in-house spreadsheets?

[Art Montemayor]

Sheiko:

Please don't jump to conclusions. No one has said that simulations should not be run.

I believe what most of us are saying is that is seems quite an overkill (& not to mention wasteful of a $50,000 simulation program) to use Hysys to calculate fluid flow problems.

Are you certain that Hysys uses "the same basic equations (Darcy, Churchill, ...)" ??? Have you ever had access to the total simulation algorithm (and equations) that Hysys employs in its simulation?

[sheiko]

Sheiko:
Are you certain that Hysys uses "the same basic equations (Darcy, Churchill, ...)" ??? Have you ever had access to the total simulation algorithm (and equations) that Hysys employs in its simulation?

Art,

I have to confess i am not certain for Hysys, however Promax does use Darcy, Colebrook (even Churchill, Jain, ...) equations.

I agree that there are simpler and less expensive tools but the OP was "Could you please tell me if line sizing can be done using hysys...". The answer is probably "yes". However, i encourage the OP to check the HYSYS equations via the help menu or the theory manual.

[djack77494]

sheiko,
I may have come across a bit too negative on using simulators in my previous posting, but I still say you should master the art of line sizing outside of Hysys, etc. before using them. Think about what you are doing. You need only to calculate the fluid's velocity in the pipe for most sizing. There are a few occassions where you may need to consider the pressure drop in addition to the velocity. That's not rocket science. So you either (manually) divide the fluid's volumetric flowrate by the pipe's cross-sectional area to get velocity, or you set up a model to do this simple calculation for you. Doing the former, you get "a feel" for pipe cross-sectional areas, reasonable fluid velocities, etc. Using a simulator does not bestow the same benefit. Ultimately you must deem your velocity acceptable or not and you're done. This is such a simple calc that I can't imagine the best simulators feeling they could set up their models quicker than I could knock out an answer with a calculator. Go to 2 phases however and I'm going to double click on my simulator too (but I could also do it manually).

[sheiko]

FYI an interesting article related to this discussion:
http://www.chemicalp....html?page=full