2 replies to this topic

[SawsanAli311]

Dear All,

1) I am currently analyzing why power failure is one of the governing extreme scenarios driving the compressor into surge and dictating the size of the anti-surge valve and the requirement of hot gas bypass. Is the root cause that upon power failure, the gas will be imposing the inertia on the compressor which has come into halt/stop upon power failure? or is it attributed to closing the inlet and the outlet valves when the compressor stops?
The trajectory of the operating point is that it tends to be driven to the left of the SLL and if an adequately sized ASV is in place, it will be driven back to the right of the SLL.

2) Additionally, when the compressor stops by ramping down, do you agree that as we reduce the speed, the operating point would be more shifted closed to the SLL and hence rundown surge during shutdown shall also be checked.
I have discussed with one of the compressor control manufacturers about the surge issues during a power dip in the plant and they agree that when there is a sudden dip, the point will be dragged at lower speeds to be fall in the zone near SLL. Do you agree?

Thanks

Regards,

Edited by SawsanAli311, 11 November 2019 - 01:00 PM.

[Bobby Strain]

I know of one installation where the anti-surge valves close when the motor is tripped. The motor is ~ 20,000 HP. The compressor is in propane refrigeration service.

 

Bobby

[breizh]

Hi ,

Some literature about anti surge valve and anti surge system.

Hope this is going to help you .

 

Note : Please don't highlight your text in purple , difficult to read !!

 

Breizh