Fuel purge

Ahmedetrby,

What is prompting you to ask this question?

Is there some condition or operational problem that has you asking why there is no secondary gas manifold purge?

In my personal opinion, gas fuel purging is necessary when there is a high risk of hot combustion gases flowing into fuel nozzles and circulating through the manifold between combustors. Yes, purging also serves to push out any combustible gas from the manifold and fuel nozzles (and there are multiple primary fuel nozzles in each combustor as opposed to a single secondary fuel nozzle in each combustor). The likelihood of hot combustion gases flowing into the secondary fuel nozzle and then into and through the secondary fuel manifold into other combustors is not very high. But, this is just my own personal opinion.

If the secondary fuel nozzles of a dual fuel machine are being damaged it's more likely there are problems with assembly than with reverse flow of hot gases--but without a lot more information about why you are asking this ”simple” question there's not a lot more which can be said.
 
Ahmedetrby,

Depending on the age of the unit you are referring to, GE Belfort has control over the design and control philosophies of GE-design Frame 9 (E/F) heavy duty gas turbines, and it's likely your question would be best directed to them. No one really knows why GE Belfort does some things, only that many things they do, they do simply because they can. They have a history of rejecting decades-old and repeatedly proven control philosophies in favor of (usually) very complicated and unusual methods and practices. So, at many times, while one can only speculate (as I have done above), the usual answer for questions like this about machines under GE Belfort's responsibility is: Because they believe they have a better idea and now that they don't have to justify their reasoning or beliefs to GE USA they will change things to be as they believe they should be (and should have been).
 
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