The Red Brick Times

Got to tour a real live electricity generating plant last Friday. You may have seen it about 5 miles into Michigan along I75. At the Erie/Temperance exit (exit 5), if you look to your right, you will see a big building with three medium height smoke stacks jutting out of the top. That is the JR Whiting generating plant. The plant manager took me on the tour from the top down. Once we climbed eleventy hundred flights of slippery open metal grid stairways and walked along the side of furiously raging boiler fireboxes, we came out on the roof. Have you ever been in a really hot sauna? Breathing the air near the top of that plant was just like that - it felt like lungs being singed with every breath. It had to be 180 degrees up there. The building is about 8 or 10 stories tall. From the roof you can see way out onto Lake Erie. I could see the Detroit Edison Fermi power plant to the north, a Toledo Edison plant to the south, Davis Besse's cooling tower to the southeast, and was told that when the haze was gone, the cooling tower plume from Perry (east of Cleveland) could be spotted as well.

On the way down, we saw fans the size of greyhound buses, with electric motors the size of Buicks to drive them, the steam chamber at the top of each boiler, where the steam and water are separated and water level is monitored, coal bunkers loaded from the top and gravity-fed down to the basement crushers, hundreds of miles of pipes, valves, hot surfaces, massive castings, girders and, unexpectedly, levels of concrete floors and walls all covered with red industrial tiles. In one area that was roped off for some reason, the clay tile floor was black, covered with coal dust and grit. That is what the entire place would look like if it was not regularly swabbed out. And the noise! The whole place fairly thrummed with the energies of the inferno roaring inches away. Through ear protection, one had to fairly shriek to be understood.

The lowest level housed the coal pulverizers, taking the gravel-sized coal down to something that could be moved by air. These pulverizers use steel balls the size of huge cannon shot, which are used until they wear down too small to be effective. There were racks of them along the wall waiting to be installed. The pulverized coal is blown upward to mills that grind still finer, until the coal is the consistency of talcum powder. The powdered coal is blown into the boiler through burners that look like oil burners. The boilers are, in fact, fired on oil from a cold start, and then switched to coal powder when the heat rises sufficiently to support combustion.

There is a 4-mile long channel that supplies lake Erie water to the steam condensors. The boiler water itself is separate and is recirculated through the system. There are pumps everywhere to keep the fluid flowing. A great deal of process equipment is water cooled to prevent heat damage.

The steam turbines have several stages to take full advantage of both high and low pressure steam. Incoming water is preheated by exhausted steam, and incoming air is preheated by exhaust gases, to increase efficiency. Exhaust gases are sent through electrostatic precipitators to remove particulates. Stack gases are continuously monitored for NOx, CO2 and clarity (particulates) and the boiler burn is adjusted accordingly.

The generators that are driven by the steam turbines are cooled by pressurized hydrogen gas. There is a tank farm with big hydrogen tanks to supply the several hundred cubic feet per day required to do the job. The hydrogen not only carries away heat, but insures a lack of carbon (ie: from carbon dioxide) that could create conductive arc paths on the armatures leading to flashovers and short circuits in the intense electric and magnetic fields. Also keeps the ozone production low. For maintenance, they shut the generator down and flood the housings with carbon dioxide to displace the hydrogen, then ventilate with compressed air for several hours to permit safe breathing environments inside the housings.

Oddly enough, if the plant is ever shut off from outside sources of power (the grid becomes disconnected) they have to trip the plant to shut down the generators. There is too much energy being produced and it needs a load to prevent voltages and currents from destroying the equipment. The plant cannot run itself. Once the generation is offline, there is no power to run the ancillary equipment. I spotted a generator that must have come from a diesel locomotive in a corner of the basement. The plant manager said it was actually run on propane. Its primary purpose is to keep the steam turbine/generator shafts turning over at very slow speed during outages. There are motors connected to the shafts that do this. If the shaft is permitted to sit without rotating, the intense heat inside the assembly, rising to the top as circulation is shut down, differentially heats the huge steel shafts (he held his hands about three feet apart to show diameter) and they will bow upward and be destroyed. So they have to turn like rotisseries to stay evenly heated.

There are two coal piles. One is Western coal and one is Eastern coal. Eastern coal has higher btu content (19oo or so btu per pound) and costs over 120 dollars per ton. Western coal has around 700-800 btu per pound and costs around 70-80 dollars per ton. They cannot meet design Megawatt output burning 100 percent Western coal, so they mix it in the first crushing tower out in the stockpile/rail yard. They balance megawatt load demand versus coal cost to balance the mix percent.

This plant was build fifty years ago, and has been online 24/7/365 since started. One notable exception was exactly five years ago during the big blackout, when all of the affected power generating facilities had to go offline or be severely damaged by overloads and reflected power surges.

About 5 years ago, the three boiler operators and their chief (one team per each shift) were supplanted by an electronic central control system. In the control room, surrounded by fifty-year-old levers, meters and switch panels, four modern console desks, each surmounted by four huge flat-panel monitors, watch and control the entire plant operation. Being an older plant, there are still a raftload of valves and gates that need manual control out in the plant, but everything important, from Megawatt output to water level, can be controlled from these consoles. It was like a Star Wars starship bridge control panel, only where a bank of flashing lights and switches are always assumed, 328 Megawatts of potential energy was controlled by a lowly mouse and some right and left clicks.

If you go to Google Maps and type in " jr whiting generating " to search, you can zoom in on the satellite view and see the overhead layout of the plant. The ponds to the north are the fly ash pits. They are clay and terracloth fabric lined, cloth and clay capped, earth covered and replanted when full.
Posted 6:04 PM by Andy (0) comments

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