Restart requirements 1

[stzatzop73]

On site we have a GE 9FA turbine. From AS BUILT manuals, GER 3620, there is a table for Turning. These are the generic operational guidelines for the time that the GT should be at turning after a shutdown or a trip and then restarted for normal operation. Verbally we also have been informed that GT can be restarted in less than 8 hours following a shut down if the wheelspace temperature is higher than 200 oC. Do you have any operation guidelines from GE on that issue? As you understand restart times are critical to avoid abnormalities on main GT parts but there is no automatic protection from MArk VI logic on that.

 

[abeltio]

There are several vintages of 9FA: 9FA.01 (9FA) and 9FA.03 (9FA+e)

Depending on the unit configuration there are different maintenance factors and also there is a TIL that may apply.

Also is very important to know if the unit is in a single shaft combined cycle configuration with a steam turbine directly coupled or not.

To clarify your question more data are required.


saludos.
a.

 

[rmw]

All shut downs are not the same, so there can't be one rule that fits all. There is a world of difference between a normal shut down and a full load rejection shut down. Then there are an infinite number of combinations in between.

rmw

 

[Romefu12]

Restarting a 9FA after a trip or normal shutdown, regardless of vintage is simply at the customer’s own discretion. GE directive is to restart the unit within 2 hours for minimal effects after a trip from full load. If the unit is not restarted within 2 hours then GE recommends the unit go on turning gear for 8 hours to reduce the effects of aft compressor rubbing from decreasing clearances in compressor stages 13 thru 17 during cool down . However GE only recommends this practice and is not mandatory. TIL 1502-R1 explains the issue clearly.
Romefu12