Start-up Sequence of GT Frame 9

M

Thread Starter

Moh

Hi everyone,

I'm new here in this siteweb, I would like to understand the start-up sequence of Turbo-generator and the turbine used is MS9001,

My purpose is to know how this rotating machine start up until reaching its complete sequence (Idle speed). and also how the synchronization of generator works.

I hope someone can provide me the full informations about this question

Best regard

Moh
 
Moh,

Welcome.

There are GE-design Frame 9<b>E</b> heavy duty gas turbines. There are Frame 9F turbines; there are Frame 9FA units; there are Frame 9H units; there are Frame 9HA units. (There are the numerical coded units, also: 9FA.03, etc.) Which type of Frame 9 (MS9001 (Model Series 9000, Single-shaft) turbine do you operate?

What type(s) of fuel(s) does the unit burn during starting?

How old/young is the unit you are operating?

What type of control system does it have?

For information on synchronization, you can use the cleverly hidden 'Search' feature of control.com. For desktop versions of control.com, the 'Search' field is at the far right of the Menu bar at the top of every control.com webpage. (For mobile versions of control.com, it's found under the Control.com tab.) The syntax of searching on control.com is probably unlike your preferred World Wide Web search engine. For example, if you want to search for the word "synchronization" you would type the following into the 'Search' field and then press ENTER on your keyboard:<pre>
+synchronization</pre>If you clicked on the search result "Manual Synchronization" the following thread would be displayed: (you can click on the link below to get to the thread):

https://www.control.com/thread/1563829696

As with any search engine, you have to be creative when searching for things you're looking for. And, it's highly recommended you use the control.com 'Search' Help the first couple of times you use 'Search' to get a feel for the syntax of searching on control.com.

As for starting a GE-design heavy duty gas turbine, that topic, too, has been covered MANY times before on control.com, and all of those threads can be found using the 'Search' feature of control.com. But, for now, we'll start with the basics (until you provide some more information as requested above).

--Operator initiates START

--The starting means starts
(the starting means is used to break the turbine-generator shaft away from zero speed (get it turning from an at-rest condition; on Frame 9E units the starting means is almost always an electric motor, a very high voltage, medium horsepower electric motor) and to accelerate it to purge speed

--The turbine goes through a purge, using the starting means to rotate the axial compressor shaft (which is part of the turbine shaft) to cause air to move through the compressor, turbine and exhaust to remove (purge) any combustible gases from the unit to prevent an explosion when the ignitors are energized

--At the completion of the purge (on most, but not all, Frame 9E units) the unit is allowed to decelerate to approximately 9.5% speed, at which point the starting means begins to re-accelerate the unit slowly

--At approximately 10% speed the ignitors are energized and fuel is admitted to the turbine's combustors; flame should be established in less than 30 seconds (usually much less than 30 seconds, especially for natural gas fuel)

--Once flame is established fuel is cut back a little and the unit continues to accelerate from the torque of the starting means to allow the unit to warm up slowly (more slowly than if the fuel were held constant); this helps to prevent thermal stresses to the internal turbine parts

--Once the warm-up period is complete the fuel is ramped up to achieve a desired acceleration rate (if the turbine has a Mark V, Mark VI or Mark VIe control system); the starting means is still providing torque to help the turbine to accelerate because there is not enough energy from the hot combustion gases flowing through the turbine to sustain speed or to accelerate the turbine

--Once a Frame 9E reaches 60% speed the starting means is uncoupled from the turbine-generator shaft and the unit will accelerate based on the torque produced by the combustion of fuel and the hot combustion gases flowing through the turbine section of the unit

--When the unit reaches approximately 70-80% speed the IGVs (Inlet Guide Vanes) will open from their "closed" position (usually 34 DGA (DeGrees Angle) to the minimum operating angle (usually 57 DGA)

--When the unit reaches approximately 95% speed the Aux. L.O. and Auxiliary Hydraulic pumps will be shut down, the compressor bleed valves will close, some compartment vent fans will start, the generator exciter will be started and generator terminal voltage will start increasing very quickly to rated and the unit will continue accelerating to approximately 100% speed (usually 100.3% speed to be exact)

At that point the operator decides to synchronize the unit. Most turbines have both a manual- and an automatic synchronization mode; most sites use automatic synchronization (which does everything an operator would do and then close the generator breaker). At this point the without any operator action, the unit goes to what's called "Spinning Reserve" which is a minimum amount of load (electrical power output). NOTE: Once the generator breaker closes the turbine-generator speed and frequency are held to whatever the grid frequency is (speed and frequency are directly related). If the electrical load of the machine is increased or decreased when the unit is synchronized to the grid the unit speed will not change (unless the grid frequency changes). To produce more electrical power, the turbine control system increases the fuel flowing into the turbine's combustors. To decrease the electrical load, the turbine control system decreases the fuel flowing into the turbine's combustors.

That's about it. We need to more about your unit, as requested above. The basic steps are: START; purge; fire; warm-up; accelerate to FSNL (Full Speed-No Load); synchronize; load/unload as required.

Hope this helps!
 
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