We are operating two GE Frame 5 gas turbines with dual fuel system. when turbine is shutdown with lube oil circulation on, worn AA compressor seals cause oil ingress into atomizing air circuit. Since we operate turbines only on gaseous fuel, we want to remove atomizing air compressor.

We have never performed any maintenance on accessory gearbox and atomizing air compressor before.

We need any procedure/instructions for atomizing air compressor removal on GE frame 5 MS5001P gas turbine.

 

Is it possible (considering available space limitation) to on GE frame 5 MS 5001P to discouple the atomizing air compressor by sliding it towards Inlet plennum removing hub which couples compressor to quill shaft and then mounting compressor back to accessory gear so that compressor remains out of operation when turbine is operated?
Is it safe to operate with quill shaft discoupled from atomizing air compressor but coupled with accessory gear shaft or it is necessary to remove quill shaft to discouple atomizing air compressor

 

Can you share P&I of AA/Purge air/gas & liquid fuel system of your machine..

AA system also linked with purge air system. Atomizing air also served as cooling air for fuel nozzle. Removal of AA compressor is not any issue but you have think about other arrangements linked with atomizing air system.May be some by pass piping required to keep live the required circuits..P&I diagram may help us to understand the actual system of your machine.

Thanks

 

Dear FSX,

Any changes in the atomizing air system will have impact on the associated system such as the fuel nozzles. You should be careful with removing the atomizing air compressor only; If you remove the atomizing air compressor, you should also consider to retrofit the fuel nozzle or change to single FG nozzles. In normal FG operation the atomizing air prevent backflow (purging the LF nozzle passages and the atomizing air lines) of hot combustion gases and at the same time cooling the LF fuel nozzles.

Removing of the atomizing air compressor may also give you additional 200kW (consumed compressor power from the AUX GB).

What ever we tell you here in this forum, you are on your own. If doubt, consider consulting the OEM.

Good Luck,
A. Oztas

 

if the piping are not remove:
Is it possible to change the fuel (gas to dist.) in F.S.N.L or loading?

 

if you look at the P&I of AA/Purge, in the absence atomizing comp. air compressor discharge out put is substituted. the air can be a viable alternative for purge?

 

Dear all thanks for your reply

please note that during last shut down of turbine there was heavy oil leakage into atomizing air system. This leakage was suspected to be from worn atomizing air compressor seals. This oil leakage was so excessive that it caused fire in exhaust stack. Also gas turbine tripped several times on over speed during startup.

To prevent oil from leaking into hot gas path fuel nozzles were seal welded at atomizing air, purge air and liquid fuel inlet connections.
Atomizing air compressor discharge was vented to atmosphere by modifying atomizing air piping and turbine was put into operation.

Now we only want to discouple atomizing air compressor from accessory gear box so that it can be put out of operation and its suction and discharge connections can be blinded off.

Please advise if it is possible to do so without removal of accessory gearbox upper cover.

Can we slide atomizing air compressor back towards inlet plenum to disengage it from quill shaft coupling hub and lift it out?

Any procedure or experience sharing will help a lot

 

Is it safe to operate atomizing air compressor by blinding off both suction and discharge lines?
The model and manufacturer of atomizing air compressor installed on our turbine is
Gardner Denvar Co.
DWG # 203SMA799