Russel City Energy Company Turbine Failure 6

[TugboatEng]

https://urldefense.proofpoint.com/v...ObyyNG-yTKkaeVH_EyhD6lMCD1-kLH6d9sh4-kdhE0&e=

The operator wants to keep the report confidential citing security concerns. That's usually a bad sign.

 

[dik]

I read through it, and it made my head hurt... almost as bad as a political speach.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[TugboatEng]

It came from this article which isn't much easier to read:

https://www.ktvu.com/news/hayward-power-plant-explosion-blamed-on-equipment-design-flaws

 

[dik]

Thanks, Tug...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[MJCronin]

MBAs always demand confidentiality for "Security Concerns" .....

Reading the CALPINE statement posted above made me feel like it was written by a North Korea true believer ...

Steam Turbines have blown up before .... its too bad that a competent team like the one at CSB will not determine the root cause.

Remember, Calpine has many many Combined Cycle plants across the US and they are all about the same ...

MJCronin
Sr. Process Engineer

 

[dik]

MBA? Master of Business Admin?

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[1503-44]

It's MBA speak for lawyering up.

 

[spsalso]

We have here a likely testimonial to my new product: Spray-on CYA. Simply apply where needed. Multiple applications may be required.

Are you the guy who's left holding the bag when someone else specifies a problem component? SPRAY-ON CYA!

Are you on some government board that's supposed to oversee stuff you never heard of? SPRAY-ON CYA!


Money back guarantee, but remember: "WE have CYA!"


spsalso

 

[dik]

Hehheehe...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[1503-44]

Flourescent orange. Can be applied directly to seat of pants.

 

[bones206]

I read the report and I thought it explained the root cause quite clearly.

 

[wayne440]

...We have here a likely testimonial to my new product: Spray-on CYA. Simply apply where needed...

Does that work similar to the blame deflection necktie?

 

[spsalso]

It's very similar, though mine is in an easy to apply spray can. Once you figure out how to get the cap off.

SOME people have trouble installing a necktie around their neck. I understand sometimes users put the blame deflection necktie on BACKWARDS, with very unfortunate results!


spsalso

 

[byrdj]

I never work "combine cycle", so with out plant specific drawings, I thought the explaination was fair. actually, I was able to anticipate the event and conclusion.

Normal steam turbine overspeeds from "heaters" was a BIG concern and given the simplicity of the use of flapper non return valves made most not take that protection serious. then water carry over rendering emergancy trip valves useless

 

[TugboatEng]

I'm curious, how did water from the HRSG end up in the steam chest/throttle if it was part of the reheater?

 

[byrdj]

The inability to detect and mitigate the presence of excess water under pressure and at high temperature within the facility’s reheater system.

accumulation of water in an offline heat recovery steam generator (HRSG) due to the mechanical failure of a gearbox on a cold reheat stop valve…prevented the valve from fully closing … causing steam to pass through the valve and condense in the offline HRSG

the colder water from the offline HRSG passed through the hot valves feeding the steam turbine, the valve components were thermally distorted … preventing their closure.

The continued flow of water followed by the flow of steam through the seized valves provided the energy source to accelerate the steam turbine into the overspeed event.

I think the "reheater" is actually the steam generator.

the inability to have indication of a failed state was one of the big heart aches I had when I attempted to assist with the conversion of older turbine controls to modern computer controls. (oh, I did have the "big one" that forced my withdraw)
the simpliest was reduntand but diverse indications. ie, the motor drives used an LVDT for position and THEY used indications of that LVDT for their redundant open/closed indications. where physical mecahnical limit swithes original.

But I have to say getting plants to actually set limit switches for true open / closed was near impossible.

Oh and the root cause of design error sounds very familiar to a "wreck" I was supose to be working to get money from the "deepest pockets", but all my findings were operator error, and my services were no longer needed

and as for detection of water level in a device that should only have steam

 

[TugboatEng]

For setting limit switches, even if the valve is closed that's a big assumption to say that it's shut off. Valves leak, especially when steam is involved. It seems like there was a vent or drain on the HRSG that should have been opened while offline and that wasn't done.

 

[AusG]

In da oil biz, upstream anyway, we test valves and other seals by holding a pressure differential whatever the position of the valve or actuator might be. Liquid in a vessel designed for gases could be tested for by a pressure gradient. Quartz pressure gauges are all solid state and reliable. I'm sure these folks know their biz and have good reasons for using other tests but I'm wondering what those reasons might be?

 

[stevenal]

Sure they are covering themselves. Disclosure of critical energy infrastructure information (CEII) is serious. From the letter, they have done the analysis, presented the results, and have formed a plan of action. What are the critics here suggesting they do further?

 

[TugboatEng]

We get access to complete analysis of every aircraft crash. Why should power plants get an exception?