SearchUser loginOffice of CitizenRest in Peace,
Who's new
|
Russian Hydro Accident - Armchair photo forensicsSubmitted by Jeff Buster on Tue, 08/18/2009 - 10:31.
Take a look at the lower two images from BBC and help me understand how a transformer explosion could lead to the generator breaking loose from it's foundation and blowing a huge hole in what looks like one meter thick reinforced concrete? It looks like the generator was rotating when it broke loose, because you can see the windings are all twisted in the same direction. The left hand photo shows that the penstocks were ruptured, blasting water directly into the power gallery and washing debris out onto the roadway. Could this really be set off by a transformer explosion? Are the transformers in the Generator Hall? Or outside? I have not had time to research the layout of equipment at Sayano, but often the turbine is below the generator floor. Rather than a transformer explosion, which the BBC reported, it seems more likely to me that the turbine ran away and self destructed taking the penstock with it, or that the penstock ruptured - and an 800 foot tall column of speeding water entered the turbine room, ruptured the concrete floor upward sending the rotating many many ton generator spinning around wildly like a atomic top. Who's got another quess?
( categories: )
|
Recent commentsPopular contentToday's:
All time:Last viewed:
|
Armchair forensic engineering - Sayano dam accident
Hydro Accident
Generators are located under the floor level shown in most of the photos and videos. The turbines would be located below the generators. The turbines are most likely "francis" type with a case like a flat snail shell. The transformers(orange, three per generator?) are between the building and the Dam, just upstream of major damage.
Most likely a mistake or failure in the control system caused the first turbine and generator to "run-away." This could have been a short or overcurrent of the main transformer. Or overheating due to loss of coolent, etc.
There should have been a controlled shutdown of the turbine on loss of load by the safety equipment and turbine controls. If these controls operated late or failed, then the turbine speed increases to a maximum overspeed, and then if the water is stopped quickly, the result is a very large water hammer surge. this is like the banging of pipes in the house when the water flows fast and then is stopped suddenly. This would cause failure of the pipes or turbine case, and the associated flooding the damage to the other two units which were operating.
WOW!