Posted on 01/12/2017 11:45:30 PM PST by greeneyes
An explosion of Unit 1 of the J.M. Stuart Station shut down the coal-fired Ohio plant and injured six people. Officials at Dayton Power and Light have said theyre still determining the cause of the explosion at the 2,318-MW plant in Aberdeen, Ohio, reported the Ledger Independent.
(Excerpt) Read more at power-eng.com ...
That will probably work out as well as New England buying from Hydro Quebec, $.38 a Kwh. National average is $.09
It could be called once through but it definitely has a Reheat Stage. Super Critical Boilers just jam the water in on one end and it comes out as steam on the other. Older types have steam separating headers that recycle hot water through the Boiler section. After this the steam is superheated and sent to the Turbine. This is all about funny properties called Enthalpy and Entropy and how energy can be ripped out of the heat imparted in the steam.
In a Supercitical unit, the water is actually pushed into the unit at 4500psi.. and by the time it gets to the Turbine simple hydraulic resistance decreases the pressure to 3600psi. The water never really flashes to steam, hence supercritical, and instead it just gets hotter. It goes through the water walls to contain the fireball of the furnace, then through the economizer to pick up heat from the last gases leaving the furnace, then through the primary superheater, then the secondary superheater then down to the Turbine.
Steam leaving the turbine is fed back up the the Reheater and then back down to the Turbine one more time and then into the Condenser where it is cooled to near room temperature by the cooling system which creates a vacuum. If you ever heated a gas can with water in the bottom and screwed the lid on, you can see what this does.. schlooop! The suction pulls that last steam across the biggest low pressure turbine blades before it gets cooled. This wrings that last tiny bit of energy out of the steam.
Vtengma wrote: “That will probably work out as well as New England buying from Hydro Quebec, $.38 a Kwh. National average is $.09”
Ouch! Yes, this was Obama’s plan.
I have seen the results of a pressure tap failure and it wasn't pretty.
This unit is controlled by a huge analog computer that about half the size of a basketball court. It is possible to cook the secondary superheater or the high temperature reheater section which will get you popped boiler tubes.
But, when it comes down to it.. start-up is very different from operation in these units. But, I never actually had any training on this just the same so I don’t have a clue about the tricks or the challenges.
First, a pulverizer mill “puffed” (I’ve never understood why an explosion of such magnitude is called a puff). The resulting pressure fed to the igniters blows out the ignition, then after a few seconds, KABOOM! The fact that the explosion was heard first, then the black smoke, leaves little doubt in my mind.
The one that was somewhat recently demolished downtown was closer to Downtown, across from Sinclair Community College.
It’s been forty years, I drove South on 75 past it on my right, and the cliff were South a bit on the right of the northbound Lane. Both are huge tall...
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