GE Frame 7EA gas turbine fire protection. 1

[blacklabs]

A fire in the load tunnel trips the unit.I believe the following should happen:
CO2 will dump into space.
A/C lube oil pump will trip.
DC lube oil pump will come on providing sufficient oil to bearings for roll down.

Question: Does the DC lube oil pump run continuously or does it cycle on and off on the way down? I think it should run continuously on the way down and cycle on and off when it gets to zero speed.
Thanks in advance for any help!

 

[magicme]

somebody at GE must have written a turbine emergency shutdown sequence.

..... I think.



magicme

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"not all that glitters is gold"

 

[blacklabs]

Very clever. Thanks!

 

[winpop123]

May not help but here goes.

When suppressing a fire in an aircraft engine (turbine) nacelle, the first steps are to shutdown the engine and the fuel pump. Then and only then do you introduce the fire suppressing agent. Otherwise you risk having all the agent blown out the back of the engine and/or having the fire re-ignite due to fuel spraying on hot surfaces.

good luck

 

[magicme]

blacklabs

i did not mean to be clever or sarcastic.
I know GE writes startup and shutdown procedures for their gas turbines and they re-write them sometimes to deal with troublesome LCF items.

I was thinking they may also have an emergency shutdown sequence written.

magicme



------------------------------------
"not all that glitters is gold"

 

[toothless]

We have three GE 6B's. The DC pump should come on and stay on.

Fire doors will also close to trap the CO2 inside the compartments.

 

[rmw]

The pumps should stay on. The shaft is running on a hydrodynamic wedge of lubricant which is supported by the bearing surface. To shut the pump off is to lose the wedge and allow metal to metal contact at high speed. It is a formula for disaster or replacement bearing sales.

The wedge is lost at low speeds, but the shaft speed is low at that point. Some units avoid that by having jacking oil pumps to maintain an oil wedge under the shaft even at stop.

rmw