lay down area for CCPP

[morojlu]

The question is that in a combined cycle power plant unit with a 2GT x 2HRSG x 1ST configuration which its gas turbine capacity is 160 MW, what lay down area is required?

- What parameters are important and effective in determination of lay down area?

- If the number of units with the above mentioned configuration reaches to 2 or 3 units, does the lay down area increase exactly to 2 or 3 times the first area?

- If the gas turbine capacity gets to 250 MW with the first configuration mentioned above, what is its impact on the lay down area?

 

[MJCronin]

Dear 1677879761,

This is a tough question to answer.....and falls under the specialty skills of Construction/site manager.

The laydown area requirements are dictated by the project's equipment needs as well as the sequence of construction and delivery. HRSG delivery times and sequence will dictate much of the real estate needs.

The best course of action is to find out the laydown area of a similar CC plant, then increase it by 50%

You should also consider different types of laydown/parts storage area. It is more economical for some assemblies and components to be as near as possible to the installed location (HRSG "harps" come to mind). Whereas, other parts may be reasonably located a short distance away.

Sometimes developing site layout (commonly called "turf")drawings for contractor meetings, can help....

My opinion only......

-MJC

 

[abeltio]

what laydown area are you talking about?
1. laydown of materials for construction
2. laydown of parts during maintenance

from you question i understand you are trying to define the plot plan of the plant for maintenance once the plant is built.

it all depends...

do you have overhead cranes or you need deck area to bring one in for maintenance?

do you have the GT's inside a building or outside? are the temperatures mild enough that will allow maintenance any time of the year?

are you planning to maintain the whole CCPP at one time or are you staggering the GT's and the steamer?

can you operate in bypass? i.e. both gt's and no steamer

how expensive is the real state at that location?

what kind of enclosure have the units? on-base? off-base? no enclosure?

who will perform maintenance? in-house crew? contractor?

what are the environmental, health and safety requirements at that location? do you have to supply office and trailer space to the crews?

ooops... now you have more questions and no answers... sorry.


saludos.
a.

 

[morojlu]

Dear Abeltio

Thank you for notification of various aspects.Let me answer some of your questions:

-Laydown area is only needed for maintenance.
-GT is inside a building.
-Temperature range in the site is so wide.
-CCPP is equipped with Diverter Damper so CCPP can operate in bypass mode.
-HRSG is always outdoor.
-The in-house crew perform maintenance.
-there is no strict environmental requirements.

I would appreciate if you could explain more about other parameters or guide me to some sources in this regard.

 

[abeltio]

1677879761
you did not mention if you had overhead cranes.
i will take it that you do... since the units are inside the building.

make sure that:

the crane is capable of lifting the heaviest rotor + 20% to account for all the rigging and lifting beams.

the area available for laydown allows for 1.5 m all around each piece of equipment laid on the deck.

consider that you will not maintain any rotor on the deck because cleaning will require building a tent and scaffolding around each rotor... and the noise level of the cleaning equipment will preclude any other activity... affecting the duration of the outage.

the size and weight of each casing is usually given by the OEM in the service manual.

consider that to expedite the maintenance besides the overhead crane you will need as well a mobile crane within the building (usually a 20ton crane)

if the gt has an enclosure... ensure that there is ABSOLUTELY NO EQUIPMENT INSTALLED ON THE ROOF - otherwise removing the roof becomes a nightmare.

ensure that the design incorporates features that will allow removing the the enclosure walls easily.

ensure that you have 1.5 times the generator field length available behind the exciter end coupling flange of the generator to allow for field removal.

do not allow cable trays and/or conduits running along the enclosure walls or roofs.

in front of each heat exchanger head: consider 1.5 times the length of the heat exchangers tube bundles for removal.

ensure that you have enough space to locate 2 x 20ft tool containers on deck.

ensure that the deck can support the rotors (depending on the unit size) - biggest gt rotors in the market are around 75,000 kg - overhead cranes need to be 90ton, 100 ton a blessing and not much more expensive.

ensure that the access to the overhead crane is such that in case of a failure the operator can leave the crane booth and is not trapped 25m up in the air.

HTH




saludos.
a.

 

[norzul]

check also with OEM what is the heaviest "maintenance" weight. This is for overhead crane design. I believe, Albetio has told yu everything yu require...

 

[seo]

Sounds like you are talking about a 7FA or W501F.

Plan for at least 5 acres per train.