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Jacek
11-08-2010, 12:54 PM
Hello Guys,

I'm looking for diagrams to select pipe diameter for ammonia refrigeration installations. It would be great, if you had the diagrams with SI units.

Many, many thanks in advance for your assistance.

Regards,

Jacek

McFranklin
12-08-2010, 03:24 AM
Danfoss has a selection program you might be able to get from your local dealer. I have looked at it and it does SI units.

piewie
12-08-2010, 04:54 PM
You dont have the name of the program do you? I have tried to get the valve selction program from Danfoss UK many times but Danfoss UK are a really unfriendly lot here and the Danfoss agents won't part with what they see as their stuff in case you try and do them out of a job.

Jacek
12-08-2010, 06:45 PM
Danfoss has a selection program you might be able to get from your local dealer. I have looked at it and it does SI units.

Thanks.

I forgot about Danfoss.

Regards.

McFranklin
13-08-2010, 01:52 AM
It is DIRcalc. I haven't tried to download it here at home, but it was free the last time.
http://www.danfoss.com/North_America/BusinessAreas/Refrigeration+and+Air+Conditioning/Product+Selection+Tools+Details/DIRcalc.htm

I pasted the url above.

piewie
13-08-2010, 07:20 AM
I had a quick look at the dircalc program and was not that impressed I'm sure that with a bit of work you would be able to get it to work for you but manual calculation is still the best way.

McFranklin
16-08-2010, 02:23 AM
It's free. And really, since ammonia refrigeration is a specialized niche field you are not going to find much. The companies I have worked for used charts. This line size for a dry suction at this temperature, if it's liquid recirc. use the next size larger.

D.D.KORANNE
21-09-2010, 01:06 PM
You will find it in the r.j.dossat`s book page 494 . It gives you fairly close selection of piping sizes . Besides, oil return in nh3 is not a issue with ammonia , you can size the pipes . Oil separator , knock out vessel , receiver ,oil return to crank case issues are easier to address in nh3 v/s r-22 , r-404a ...... Etc. Even piping layout does not pose problems as would in cfc, hcfc refrigerant groups .

Sandro Baptista
21-09-2010, 01:40 PM
I had a quick look at the dircalc program and was not that impressed I'm sure that with a bit of work you would be able to get it to work for you but manual calculation is still the best way.

Don't total agree.

The dircalc have in count many parameters that influence the pipe selection because it counts with the correct mass flow rather than the refrigerant capacity.

Many people think that it is enough to know the refrigerant capacity and the evaporation temperature and all parameters are given to the design of the pipeline.

sterl
29-09-2010, 09:50 PM
Suggest you use the IIAR piping handbook...Its in both sets of "used" units (not true SI; rather Metric traditional?) and gives you a whole lot better picture of what specific pipe segment is encountering in terms of fluid flow than does dircalc.

Sandro Baptista
30-09-2010, 04:36 PM
The dircalc calculates automatically the fluid flow and with inlet section area it calculates the velocity and with the internal D it calculates the pressure drop based on the Reynolds.

monkey spanners
29-11-2010, 09:11 PM
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