5 replies to this topic

[Aranga]

Good evening all,

 

        we have  propylene and Ethylene refrigeration systems in our unit. Those  are 3 stage centrifugal compressors. 8900KW and 4084 KW respectively.  Both are motor driven.

 

We are in Erection stage. During the time of  Mechanical run test, can we run these compressors with Nitrogen for performance verification?

 

My understanding is that, the  volumetric flow will be the same as other gas, but Mass will be different because of the nitrogen's density. It may not be a problem since N2 is not heavier than the Propylene/ Ethylene. But any otherthings should be considered?

 

Surely, we will be having the vendor(Manufacturer) at site during the time of Trial run, They will give us the correct guidelines. But I wish to ask here, So I can get anyone experienced personnel's view regarding this.

 

Thankyou,

Aranga.

[ankur2061]

Aranga,

 

I suggest you read my post (post #7) in the link below:

 

http://www.cheresour...-temp-at-150-c/

 

Hope this helps.

 

Regards,

Ankur.

[meetyourmaker]

It is very difficult to comment on how a molecular weight change will affect the performace of your compressors without knowing more about your system specifically how suction or discharge pressure is controlled, and whether suction throtting/VFD's/ speed control are used.

Edited by meetyourmaker, 05 March 2013 - 10:42 AM.

[Bobby Strain]

These are small machines. So, I am surprised that the compressor manufacturer is not running test in their shop.

 

Bobby

[S.AHMAD]

1. As far as I know, the compressor manufactures using air or nitrogen during shop test to determine the compressor performance curve then they convert the results into the operating gas basis

2. This means that you can test the compressor using N₂, but you must know how to convert the results into the actual gas that you are using.

3. Discussion with vendor/supplier/manufacturer should help.

Edited by S.AHMAD, 05 March 2013 - 09:05 PM.

[Aranga]

1. As far as I know, the compressor manufactures using air or nitrogen during shop test to determine the compressor performance curve then they convert the results into the operating gas basis

2. This means that you can test the compressor using N₂, but you must know how to convert the results into the actual gas that you are using.

3. Discussion with vendor/supplier/manufacturer should help.

 

 

Dear sir,

 

   We are not going to match the trial run parameters with, actual gas compression. The intention is to check the compressor performance, after installation of that in process plant. Just to check Vibration, Temperature, noise, critical speed trips.., etc.

 

  I have experienced with a "recycle hydrogen gas centrifugal compressor" (7.7 MW) turbine driven tested running with nitrogen. we had clear instructions in the "operation manual" itself. But now for a refrigeration compressor, we lack of such informations.

 

Ofcourse we can(Must)  get instruction from Vendor.

 

Thankyou,

Aranga.