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Thread: Friction los calculation lines
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31-01-2007, 12:37 PM #1
Friction los calculation lines
We use for the calculation of the friction loss along the lines the formula
Dp = Re x L x rho x V(square) /d/2 where rho is the density of the refrigerant in that line, d= inner diameter, L = length of the line (and additional the equivalent length of the bends in this line) and Re the Reynolds number of the used copper.
Literarture I have gives me Re numbers from 0.015 to 0.035 (or a differencee of +/- 250% which can give me a friction loss difference of 250%)
Does anyone have more accurate numbers because you then better guess the friction loss?
Or does someone use another formula to calculate this?Last edited by Peter_1; 31-01-2007 at 10:32 PM.
It's better to keep your mouth shut and give the impression that you're stupid than to open it and remove all doubt.
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31-01-2007, 03:23 PM #2
Re: Friction los calculation lines
Hi, Peter_1
Is this of some help
Best regards, Josip
It's impossible to make anything foolproof because fools are so ingenious...
Don't ever underestimate the power of stupid people when they are in large groups.
Please, don't teach me how to be stupid....
No job is as important as to jeopardize the safety of you or those that you work with.
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31-01-2007, 10:31 PM #3
Re: Friction loss calculation lines
Thanks Josip but I think I have the same problem: what do I have to take for 'f' ??
Formula 3 inlet and outlet pressure, that's now exactly what I need to calculate.It's better to keep your mouth shut and give the impression that you're stupid than to open it and remove all doubt.
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01-02-2007, 01:16 AM #4
Re: Friction los calculation lines
Peter,
Here is a link to some material that may help you.
http://arash.dejkam.com/software/pressure_loss/
I think it is in IP, but it shows the process of calculation.
The "f" is the friction factor which you need to find the pressure loss. The friction factor is read from the Moody diagram once you find the Reynolds number.
I'm still looking for an SI version, so you do not have to do unit conversions.
Have patience...
Edit:
Perhaps this will help you Peter.
http://www.engineeringtoolbox.com/da...ion-d_646.htmlLast edited by US Iceman; 01-02-2007 at 01:24 AM. Reason: added info for my Belgium friend!
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01-02-2007, 09:33 AM #5
Re: Friction loss calculation lines
Hi, Peter_1
Take a look at this:
http://www.engineeringtoolbox.com/da...ion-d_646.html
http://www.engineeringtoolbox.com/co...on-d_1031.html
and
Originally Posted by US Iceman
It's impossible to make anything foolproof because fools are so ingenious...
Don't ever underestimate the power of stupid people when they are in large groups.
Please, don't teach me how to be stupid....
No job is as important as to jeopardize the safety of you or those that you work with.