Steam Turbines Built Outside
Steam Turbines Built Outside
(OP)
I have worked in or visited 6 fossil power plants. Each of them have the steam turbines and generators inside large turbine rooms with roofs and overhead cranes. During a turbine training class the instructor has photos of steam turbine overhauls where the turbines are outdoors with no overhead crane.
Why would a utility build a power plant with the steam turbine and generator out in the open like that? It would seem that poor weather would delay repairs during outages.
Why would a utility build a power plant with the steam turbine and generator out in the open like that? It would seem that poor weather would delay repairs during outages.





RE: Steam Turbines Built Outside
I haven't seen it done that way, but I understand how the balance could work out to favor it. In a way, it's a statement about the reliability of the equipment.
The big stuff is mostly pressurized anyway. A few adaptations, and a slightly better grade of paint, and it's weatherproof.
Mike Halloran
Pembroke Pines, FL, USA
RE: Steam Turbines Built Outside
as for problems during maintanance, YES, there are problems, even before the abilty to get live radar on internet, the utilty would have near hourly reports especially when pulling a field
RE: Steam Turbines Built Outside
Why would they do it? To save initial build cost, and construction program. I would be surprised that a utility would build a plant without a machine hall, but not surprised if a privately-financed plant was built this way. Much of the financial risk associated with maintaining an outdoor plant is moved to the O&M contractor so if weather results in stand-down time on a mobile crane and an outage crew then it reduces their profit. The owner is shielded from the risk because the O&M is usually based on a pre-agreed budget or fee of some form.
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If we learn from our mistakes I'm getting a great education!
RE: Steam Turbines Built Outside
Having an enclosed turbine room also makes it easy to stage all of the rotors, shells, and diaphragms. Right now my turbine deck is also being used to stage a lot of boiler tube panels.
RE: Steam Turbines Built Outside
O&M = Operation & Maintenance, i.e. the guys who operate and maintain the plant on behalf of the owners.
The idea of doing a turbine overhaul in the north-east of England on a pure T&M basis, knowing the likely stand-downs due to weather-related delays would fill me with concern. With crane costs running well into 5 digits per day and stand-down on the crew in the same cost bracket, a week of wind and rain can quickly add up to a serious amount of money.
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If we learn from our mistakes I'm getting a great education!
RE: Steam Turbines Built Outside
For most of the work I have done I prefer have hire the contractors on a T&M basis because most of the delays are largely under my control and I am able to better estimate their costs. Some other projects that I have worked on were fixed price for a lot of the major work but there were always countless unexpected items that popped up that were not in the original scope and had to be added to the purchase order.
RE: Steam Turbines Built Outside
RE: Steam Turbines Built Outside
My more recent experience is with the type units that Scotty mentions and none of them are inside in my part of the world at least. I have seen some inside in Canada, but it is never warm there other than the 3 days of summer that they have there. (see tongue in cheek)
Most outage work is spring and fall and except for certain parts of spring, weather is not as much of a factor in the deep south other than just waiting it out when it is too bad to work. But, then, too, the weather that time of year is fast moving fronts as opposed to the dreary days of continuous rain during the winter, so it was never too long of a wait. And, work can be done under tarps and tents.
The large turbine rooms start appearing north of a line stretching between Dallas and Birmingham as I remember it. North of that, cold weather can linger well into the spring. I can think of outdoor units in Jackson, MS and a large turbine room 90 miles north in Greenville, MS.
It is the cold as much as the wet that affects productivity to my way of thinking.
Most power plant contractors in my experience in order to get people to work that type of work wanted to work 6 tens. That gave the lads one day off to do their laundry, etc. They couldn't get people to travel away from home jobs for 40 hr/wk work.
Contractors that bid fixed price work bid it on a break even basis and then hope to load it up with higher margin work for "extras". I saw one power plant operator who did all the "extras" with their own crews and denied the contractor any extra work and that contractor still moans about that job until this day.
When you go to 12 hr days, you get 10 hrs work stretched into 12 hours. And, Knight, I agree with you. When fixed price is bid, then the contractor just has to do what it takes to get it done. But that said, then they look for every excuse to blame the utility when they can't work; say like when someone else has the crane tied up so the games go on and on.
rmw
RE: Steam Turbines Built Outside
For the turbines outages that I work on, I use in-house mechanics for the disassembly and reassembly work. We hire specialty contractors for the field machining, induction heating for bolting, etc. I am running into the issue of contractors not wanting to work straight time schedules and my company is not willing to pay any overtime. Some of the contractors will do it but are not happy about it. The only other way to do it is to pay them a fixed price, which they will most likely base on 60 hours. My opinion is that if a company is not willing to work less than 60 hours per week, then their rate sheet should start out at a rate that will cover 60 labors hours.
RE: Steam Turbines Built Outside
Some outdoor stations will also have a gantry type shelter or tent that can be rolled over a unit to protect it from direct sun and rain but which can be rolled away so that the crane can get over the unit when it has to. Back in the old days of tight-wire alignment, uneven sun light could be a bear.
http://www.industcards.com/st-other-usa-la.htm
http://www.industcards.com/st-coal-usa-tx.htm
http:
In the last one, you can't see that the unit is outdoor, but you can clearly see the turbine crane over the top of the building. You can clearly see it as an outdoor unit by flying Google Earth to Lat 29.994351 Lon 90.471492. If you go almost due north right across the river (follow the HV lines) you will see Little Gypsy station which is also outdoor units. There is a shelter over the Unit 3 turbine which I don't know whether it is permanent or constructed for an outage. It may be the gantry type tent I remember. I know for a fact that it is an outdoor unit as it was the first one I ever opened up. Got a good tan on that job.
rmw
RE: Steam Turbines Built Outside
the two yellow gantry cranes are fairly clear
RE: Steam Turbines Built Outside
I remember reading a turbine text book so this should be the standard answer: having turbines outdoors is for SAFETY REASON.
If by chance a turbine fails, the turbine house would be immediately filled with steam and dust plus possible building collapsing because of being hit by flying turbine components all could easily kill people inside.
RE: Steam Turbines Built Outside
Sorry; couldn't resist.
Mike Halloran
Pembroke Pines, FL, USA
RE: Steam Turbines Built Outside
rmw