I have some questions about the general electric MS9001E or Frame 9E

1- What is the function of the 4 oil deflectors mounted on the bearing 2 liner strap?

2- why there are 10 holes on the each side of the bearing 2 liner just below the oil deflectors?

and what is the function of the so called "spray holes" located on the top of the liner strap? "as seen on the maintenance manual"

3- What is the function of the vent holes located in between the forward oil seal and the forward air deflector on bearing 3?

4- Why the load coupling compartment is positively ventilated unlike other compartment?

5- Why we don't have 2nd stage shroud cooling while having third stage shroud is cooled by 5th stage air extraction despite being in lower gas temperatures?

6- Does the 5th stage air extraction used to cool the third stage shroud flows continuously or just static air?
if there is a flow , where does the air exits from the third shroud? "gaps between segments?"

7- what is the function of the holes under the transition piece aft bracket?

8-why specifically with DLN system we have sealing air coming from the 11th stage plus the 5th stage?
on standard we use the 5th stage only ... what changed?

thanks in advance

 

FE,

The focus of this World Wide Web forum is controls and control systems. My colleagues (and others) continually ask me why we spend a good deal of time talking about combustion hardware and valves and and vent fans and pumps--well, that's because the control system includes those components. Contrary to popular belief the control system is much more than the electronics and wires and programming and those fancy HMIs with the pretty graphics--and all those alarms, all those damned alarms. The control system includes devices that aren't even connected to the control system using wires or even hydraulics.

And to understand how control systems work and how problems can be incorrectly attributed to the control system it's quite often necessary to understand field devices and instruments--especially the ones on the P&IDs (or Piping Schematic drawings, as GE calls them). In fact, to be a good controls engineer--to be a good operator, too--one MUST understand the P&IDs, be intimately familiar with the devices on them, their operation, and their location.

And when it comes to DLN combustion systems and troubleshooting problems with DLN combustion which are almost always incorrectly attributed to the control system and almost never properly attributed to improper assembly/reassembly or problems with mechanical devices not connected to the control system, it's very necessary to understand the construction and design and intended operation of mechanical components of the DLN combustion system, which fail at a much higher rate than the control system components.

So that's why we spend more time than some think appropriate on mechanical components--the ones associated with the control system, the ones that are an integral part of the control system.

The majority of the questions you ask are not related to control systems, with the exception of some of the cooling and sealing air system/component questions. GE and its packagers seldom document incremental changes to design of either the control system or the systems associated with the control system so there's very little to go on. These days, most manufacturers are highly focused on protecting their designs (intellectual property) and do even less than was done before in the way of system documentation. And, when it comes to mechanical parts they design, manufacture and sell they don't want to document any of their design criteria or considerations because that allows other companies to understand, and possible even improve, on the OEM designs or manufacture them without having had to invest the time to design and test and troubleshoot and improve the parts--so that makes their parts cheaper and they can undersell the OEM.

Finally, there are always incremental design changes and improvements which are not documented in the life of any piece of equipment. Most OEMs are really doing just about everything they can to improve reliability while at the same time increasing efficiency and ALSO reducing costs--always reducing costs. As problems develop over the operating life of equipment--problems the OEM could never have anticipated during the design phase--they are always changing things like cooling and sealing air pressures and flow-rates and sources, almost always without much, if any, documentation.

Unfortunately, I, personally, have no answers for any of your questions--some of which I've had myself and have never been able to get answers for.

Perhaps there is one, or maybe a couple of, responders here which may have some answers--if not all. But, I suspect this forum is not the best place to ask these types of questions and get quick, concise answers.

Unfortunately, I don't know of a Frame 9E users' group like there is for so many other GE-design heavy duty gas turbines. That would be the best place to get the answers to these kinds of questions, and even some controls questions.

Best of luck!