# Alstom GT-24 gast turbine



## benbo (Nov 10, 2007)

This is a fairly specific question, but it could apply to many types of engineers so I'm putting it here. Does anybody here deal with or have knowlege of the Alstom GT-24 gas turbine, particularly in a single shaft combined cycle configuration (or any configuration really). Do you use it in a baseload or cycling market? I don't think there are many of these turbines, so I don't expect many replies, but I thought I'd put this out there.

I was originally asking about problems, but after thinking about it, probably this is not something anyone can or should discuss, confidentiality and all. So I'm just wondering if anybody out there uses them and what type of duty. Like I said, I think there are fewer than 100 in this country, so probably not many people have.


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## mudpuppy (Nov 10, 2007)

Huh, I've never heard of single-shaft combined cycle before--but then I'm on the energy delivery side of the business rather than generation. So the jet turbine and steam turbine share a single shaft with a generator? Interesting idea. The combined cycle plants I've seen have two or more jet turbines per steam turbine with a sepearate generator for each. Is one method more efficient than the other?


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## benbo (Nov 10, 2007)

mudpuppy said:


> Huh, I've never heard of single-shaft combined cycle before--but then I'm on the energy delivery side of the business rather than generation. So the jet turbine and steam turbine share a single shaft with a generator? Interesting idea. The combined cycle plants I've seen have two or more jet turbines per steam turbine with a sepearate generator for each. Is one method more efficient than the other?


Yes, you are right - most CC plants are like you describe. This one is pretty interesting - it has a GT and ST on a single shaft separated by a mechanincal clutch. They share a single generator. They have some new technology like sequential firing and an air cooled generator. And they are very efficient - with heat rates in the low 7000s according to the internet, and fairly fast starts.

But, like most fossil units (except peakers) I don't think they are really designed for a lot of cycling and load following. I'm not sure.


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