Best Plan for 100MW Gas Turbine Power Plant 1

[analystuc]

Please my organisation is intending to build an industrial park, that will consist of fertiliser, methanol and ethanol plants, with a combined power requirement of 100MW [redundancy included].

We are looking at gas power turbines as a power source. Currently, we need a 'best' plan for this. Should we go for several turbines [e.g. 25 MW X 4] or just [50MW X 2] or even just a turbine of 100MW. Advise.

 

[ScottyUK]

How can you say that you have redundancy in your 100MW if you don't know your plant configuration? 1x 100MW gives you no redundancy; 2x 50MW gives you N+1 redundancy if your load is less than 50MW, and so on. What is your actual load?

Your employer should really consider getting some expert help with this. There are plenty consulting engineers such as Parsons Brinkerhoff and Sinclair-Knight-Merz to name a couple who specialise in providing this service. A 100MW generating station is a pretty expensive proposition - get some proper help.


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If we learn from our mistakes I'm getting a great education!

 

[analystuc]

Thanks scottyuk, I didnt mention that combined load for the three plants is 70MW.

 

[ScottyUK]

Of your options presented so far, 4x 25MW just meets your steady-state load with N+1 redundancy but you are so close to the machine rating that you really need to consider whether you have any large drives - maybe a gas compressor or similar - which might be too much for the generation if the motor starts with the rest of the plant at full load. The other power plant configurations you mentioned can't meet your load and provide redundancy.

There are a lot of options and possibilities: you could run the gas turbines open cycle if the ST is unavailable for example, which would result in an awful efficiency and heat rate but would save the cost of a second steam turbine. Software like GT-Pro allows modelling of the different plant configurations to determine the optimum for your application, but it is specialised and very expensive. That's one of the reasons why I suggested getting help from people who do this type of work all day, every day.


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If we learn from our mistakes I'm getting a great education!

 

[MattNCSU03]

I second the recommendation to hire an A/E with experience in this area. One the larger A/Es could probably design and build the whole complex for you.

 

[rmw]

Another factor that affects the selection is if the CT power plants are to be simple cycle or co-gen (or combined cycle.) If steam is to be generated for plant use, that has to be factored into how the units are mixed/matched.

I second the idea of a good A/E, just get one that has done this type of work before, preferably with the exact processes you are dealing with.

rmw

 

[analystuc]

Thanks everyone. We are already in the process of contacting expert help.

 

[ornerynorsk]

You're obviously in a geographical region where existing infrastructure doesn't fill the need. You might wish to contact your local utility (or government, depending on the local arrangement) and propose co-generation. You might see an economic windfall from this arrangement, provided red-tape and greased palms would not hamper the project too much. Good luck!

 

[rbulsara]

Not A/E. Just a good E acting as a prime!

Rafiq Bulsara

http://www.srengineersct.com

 

[analystuc]

@ornerynorsk
thats an option my employers are willing to look at in the future. But now we are dealing with captive power generation.

We are currently in talks with a gas engine vendor on the possibility of using gas engines to generate 100MW. I have reservations on this though. Looking at initial cost , perfomance,load following xtic, e.t.c, I am trying to make a justification for gas turbines.
Any ideas from anyone?

 

[ornerynorsk]

Turbine vs engine ~ These thoughts come to mind: Are power requirements 24/7, or will you be on a brownout schedule (startup cycles), More readily available maint. personnel for one vs the other, parts availability, do your ambient conditions (temp, dust, etc) favor one over the other? IMO, gas turbine is a very nice way to go, if all the pieces fit. Just my 2cents, thinking aloud.

 

[rmw]

What is the availability of the fuel gas? Does it compete with your feed stock gas, or is there plenty of it to go around? In other words, how important is fuel efficiency?

rmw

 

[analystuc]

Fuel gas is readily available. We have secured an agreement with a gas utility in the region, which has abundant natural gas. I could say there is "plenty" to go round. But then fuel efficiency is also a concern. There is need to optimise fuel.
Power requirements are 24/7 for the plants, at least for baseload operation.

 

[abeltio]

Other items to consider are:

The available ratings of equipment from different manufacturers to give the best split

Remote location where parts and services are difficult to come by

vs.

A location near industrial compounds and cities

Capital expenditure vs [operational cost + flexibility]: more units give better flexibility but higher operational costs (personnel, spares)

100MW in today's state of the art is a "modest" output requirement, easily achievable with just one unit (e.g. a Frame 9E - for a 50Hz location - or similar type of unit)

Also to consider are the environmental requirements (NOx, CO2) and other local regulations. Do you require Dry NOx control? Is steam or demin water available for NOx abatement?

Another option would be 3x40MW units (Frame 6B or similar type of unit)

saludos.
a.

 

[rmw]

There are some aeroderivative packages in similar MW ranges as mentioned in the last post. One advantage they offer is that if the turbine engine portion of the package craps, it can be jerked out and replaced within ~24 hrs unlike the frame types that abeltio mentions that have to be taken apart with lots of pieces and parts scattered all over the yard. I've worked on both so I have no axe to grind. Some even come with two engines for one generator. If the power turbine or generator portion of the package crap, then you are in just as much trouble with either type, naturally. The aeroderivatives feature pretty decent heat rates too.

rmw

 

[daviwy]

you probably need an expert on this, as taking on such is a huge expenditure and you need to let go of some of the risks! experts consultants will take on some of the risks.

Likewise you should consider operating hours/cycles. are you going to be cycling hence requiring more maintenance or on a 24/7 run?

The other thing to think about is with just 1 GT your stuffed if it fails. but with more than 1 you can still provide partial load when one fails.

My other question, isnt there any Power Station already around your area that you can set up a contract with? hence removing the risks totally from your end. Because you have to think going forward
. you'd need more employees to cover the GT,
. need contracts with maintenance parties who are experts on different GTs, trust me these guys can stiff you up easily too so be careful with OEMs!!!
. won't setting up a contract with the closest PS to supply this power sort out the issue? but as one of the guys said if you dont have a PS close by that's tough!

Im obviously not an expert like some of these guys here but thought i'd just drop my opinion on this topic

Please do drop more information or knowledge you have on this subject they will all be taken in and appreciated.


David O.
Project Engineer

 

[jdfugatini]

Please consider the overhaul cycles of your machinery and the ever present need to incorporate the failure modes discovered by the OEM. Availability during your overhaul cycle or reliability issues could leave your company without a profit and net some angry customers. Also, in your analysis don't forget to include an ample supply of spare parts for routine maintenance and high mtbf's. Leadtime for parts in my present location is more that 275 days and that excludes the supp;iers' manufacturing time.

JD
Arrive alive,drive like your 55.

 

[Eamonnanchnoic]

How are you getting on? I'm a GT man myself, and 100MW of gas engines sounds like a lot, but they may be the way to go.

Are you looking at some sort of cogen options too? Because you may have a good opportunity to develop something quite efficient.