Compressor controls

[djvol]

Where can I find a good desription of control theory and methodolgy for multistage compressor control on the internet. I have found some so far but all is very superficial or not relevant to what we have. I recieved a curve ball with being given responsibilty for our compressor control and interlocking. These are 3 x 40000cfm machines running 24/24 delivering a average of 110000cfm. They have pressure and surge control with several interlocks. These are pretty aged machines that have had a "undocumented control modification" done on it about 14 years ago. Thus the original manuals does not mean much. I can acces the "control program" but do not really understand the reasoning or philosophy followed. With the technology explosion of the recent past there surely must be more efficient means to control such an expensive commodity. Not having compressor experts in abundance in the area is a problem as there seem to be a lot trying to make a quick buck and disapearing. If I can get a background that is strong it will help to select the correct "consultant" and also identify a lot of BS. Thanks

 

[pmover]

try:

http://www.cccglobal.com

there is definitely a lot of expertise available regarding compressor control theory, in addition to textbooks and technical papers.

a competitor is petrotech.

i'd digress myself, but that may be too long of a posting/response.

summarizing, centrifugal compressors must be protected from a phenoma called surge; whereby the head experienced by the compressor cannot be overcome, thus causing a flow reversal. this flow reversal or surge as the term is known for, can be catastrophic to equipment and/or personnel. the flow reversal occurs rapidly (i.e milli-seconds) and may likely continue until the head is reduced across the compressor. each centrifugal compressor is unique, in that surge may occur a different operating points.

the cccglobal website ought to have technical papers available for you to download or you can also contact there local representative and obtain useful literature from them. by the way, they have reps worldwide, so a phone should suffice.

good luck!
-pmover

 

[1969grad]

Your post indicates that each machine has surge control and pressure (either suction or discharge) control which is great. I think that the area that you want to investigate is load sharing to ensure that each machine is equally loaded. To do this you will have to have a computer (or perhaps PLC) with software to adjust the set points of each unit. This concept has been around for quite a few years but I cannot remember any website offering information. Perhaps you should contact a firm who writes control software.