Coal fired powerplants

[Cooter50]

 You are correct in that at power the hoggers do remove non-condensables but our rate of power output is in megawatts/hour.  We generate 1290+/- gross mw load less houseloads every hour.  Currently we deliver through 3 transmission lines at 345kv at 1240+/- mw/hr.  Our sister coal plant is Labadie at 2400mw/hr, this is the 140 car trainload+ of coal in 24 hours 4 boiler monster.

[Murphy Siding]

    When there is a power plant in the planning stage, do railroads actively pursue the future business, in the way that Cities and States chase after new businesses?  I mean to say, are they out there trying to sell someone on the advantages of siting a plant with access to their rail line?

[MP173]

Cooter:

I really appreciate your time and effort on this thread.  It is a fascinating subject.  It is like reading music for me, slow and even then I only pickup a fraction of the content. 

Now...when is my Ameren stock going to go up?  Is the low price mainly due to the regulation issues in Illinois?  Does Missouri also have these issues?  Was IP a good purchase in your opinion?  I was very familiar with IP as they were a long time customer.

Ed

[Railway Man]

Murphy Siding

    When there is a power plant in the planning stage, do railroads actively pursue the future business, in the way that Cities and States chase after new businesses?  I mean to say, are they out there trying to sell someone on the advantages of siting a plant with access to their rail line?

 

Usually it's the other way around -- the company that proposes to build the generating station approaches the railroad.  It's not as if the generating company has a broad array of choices.  Their site selection and feasibility process usually narrows it down to fewer sites than you can count on one hand, which often present the generating company with few or no choices about which railroad serves it anyway. 

Power plant siting is a expensive, lengthy, involved process.  It's not like shopping for a 42" TV at Best Buy.

RWM

[Railway Man]

MP173

RWM:

Would you mind sharing the top 10?

Ed

 

I probably shouldn't as it will vary somewhat depending upon which railway's perspective one uses.  And I would also be making forward-looking comments that could affect investment decisions, and using information that is unofficial and so forth, and that is not a good idea.

RWM

[MP173]

RWM:

Understood.  Kinda what I expected, but one should always ask.

Ed

[Railway Man]

Bucyrus

Railway Man

If nothing like cap-and-trade is implemented, ever, coal traffic is not going to increase radically from the level it would obtain anyway.  If something is implemented, soon, coal traffic is not going to decline radically from the level it would obtain anyway.

 

I understand what you say about coal traffic being unaffected if no carbon policy is enacted; but I do not understand your belief that coal traffic could not be forced downward by the enactment of a carbon policy.

 

Minnesota has already enacted a renewable energy policy that will clearly force a reduction in coal consumption. 

 

Please pardon me if I gave the impression that coal traffic will not be affected if no CO2 emissions policy is enacted.  It would not be affected of course by a policy that does not exist, but there are many other active affects on future coal traffic, and not a one of them I regard as having an upward influence.  Just the sheer economics of coal extraction, transportation, and combustion -- all current laws frozen in place -- are all pointing toward a long-term decline.  Coal is a non-renewable resource; the easy-to-extract coal is already extracted; the powerplants that burn it already built with cheaper dollars than it will cost to renew them, and so forth. 

In the realm of possibilities, it is possible that a CO2 emissions policy was enacted that forced the phase-out of coal consumption (and export) in the U.S. in, say, a 20-year period.  To calculate the net effect of that policy on railroads one would have to subtract that change in coal transportation that would have occurred in the absence of a policy anyway, and I don't think that the term to the right of the minus sign is going to be even close to zero.  The remainder is what a CO2 emissions law could affect.  Could it be a lot?  Sure.  Could it be a little?  Also yes.  But I don't see the votes out there to radically drive the CO2 emissions rates from coal downward.  Even California with its 20% renewables by 2020 law is going to find it virtually impossible to actually realize even a smidgen of that mandate, because the act of realizing it steps on top of all the other mandates that California has also voted into law.  There's no way to sort out which law takes precedence and the voters seem to have no inclination to do so, so the result is paralysis of action.  I doubt Minnesota's voters will get to where they thinks its going either any time soon.

If you want to see a wonderful example of how we in this nation think governance ought to happen, look at the nuclear waste disposal issue.  Nothing. Has. Happened.  It's as if it is still March 30, 1979.  Nearly thirty-one years of study and debate and planning and public involvement and votes and lawsuits and dramedy and not one ounce of nuclear waste is being disposed of according to any long-term plan.  We have no plan.  And that is why I just shrug when people worry about the horrors of CO2 laws or the horrors of not having CO2 laws because the history of the U.S. is that we don't actually do anything anymore that requires large-scale, multi-state, local-state-federal agreement over a problem with major technical, legal, emotional, and economic effects. 

RWM

[Cooter50]

 My plant was sited incorrectly along the MKT with the thinking at the time it would remain in business to serve the facility; had they only known this would close the facilities would have been sited on the south side of the Missouri(UP) or along the Mississippi(BNSF) above the Illinois River but still in Mo.  There is a old KCS spur into Fulton but the company and the current operator of the spur have not aligned to extend it the 15 miles to the plant site; pretty rough as to topography.

 As to Ameren's woes, the decrease in available funds to operate are driving the cost to procure operation loans higher, this in turn drives the return on the stock down.  This is affecting Mo. and Ill. with Illinois hurt pretty bad with the implementing of rate freeze after reduction.  Missouri rates are low and our cost to do business is rising for fuel, mechanical components, contractor repair labor for plant repair outages but the PSC looks at the stock dividends and says we make too much already.

 The infrastructure is old, transmission lines have been up for over thirty years in spots and definitely over 25 the remainder; it takes a lot of capital to reline these as well as the downtime on the line.  We are seeing excess capability in winter but for summer we always end up firing the CTG units at a price or buying from elsewhere, we looked to a new baseload nuke but that is gone now.  Sioux is almost fifty years old, Meramec is coming on 60, Labadie is over forty and Rush Island is 20+ as is our plant; the Illinois units are fairing less well: Baldwin is over 60, a third of the old IP plants are being shuttered or just closing as they cross seventy, Newton and Coffeen are the youngest but they too are well past thirty going on forty years old.  We will most likely see a few of them closed for good as the EPA gains momentum on CO2 and Sulfur Dioxide.

 If Missouri and Illinois do not do something to aid to constructing plants and we accept a higher rate base (I pay as any does) then the costs will escalate wildly when the old plants close and Ameren simply brokers someone else generation at a cost.

[Anonymous]

Railway Man

Bucyrus

Railway Man

If nothing like cap-and-trade is implemented, ever, coal traffic is not going to increase radically from the level it would obtain anyway.  If something is implemented, soon, coal traffic is not going to decline radically from the level it would obtain anyway.

 

I understand what you say about coal traffic being unaffected if no carbon policy is enacted; but I do not understand your belief that coal traffic could not be forced downward by the enactment of a carbon policy.

 

Minnesota has already enacted a renewable energy policy that will clearly force a reduction in coal consumption. 

 

Please pardon me if I gave the impression that coal traffic will not be affected if no CO2 emissions policy is enacted.  It would not be affected of course by a policy that does not exist, but there are many other active affects on future coal traffic, and not a one of them I regard as having an upward influence.  Just the sheer economics of coal extraction, transportation, and combustion -- all current laws frozen in place -- are all pointing toward a long-term decline.  Coal is a non-renewable resource; the easy-to-extract coal is already extracted; the powerplants that burn it already built with cheaper dollars than it will cost to renew them, and so forth. 

In the realm of possibilities, it is possible that a CO2 emissions policy was enacted that forced the phase-out of coal consumption (and export) in the U.S. in, say, a 20-year period.  To calculate the net effect of that policy on railroads one would have to subtract that change in coal transportation that would have occurred in the absence of a policy anyway, and I don't think that the term to the right of the minus sign is going to be even close to zero.  The remainder is what a CO2 emissions law could affect.  Could it be a lot?  Sure.  Could it be a little?  Also yes.  But I don't see the votes out there to radically drive the CO2 emissions rates from coal downward.  Even California with its 20% renewables by 2020 law is going to find it virtually impossible to actually realize even a smidgen of that mandate, because the act of realizing it steps on top of all the other mandates that California has also voted into law.  There's no way to sort out which law takes precedence and the voters seem to have no inclination to do so, so the result is paralysis of action.  I doubt Minnesota's voters will get to where they thinks its going either any time soon.

If you want to see a wonderful example of how we in this nation think governance ought to happen, look at the nuclear waste disposal issue.  Nothing. Has. Happened.  It's as if it is still March 30, 1979.  Nearly thirty-one years of study and debate and planning and public involvement and votes and lawsuits and dramedy and not one ounce of nuclear waste is being disposed of according to any long-term plan.  We have no plan.  And that is why I just shrug when people worry about the horrors of CO2 laws or the horrors of not having CO2 laws because the history of the U.S. is that we don't actually do anything anymore that requires large-scale, multi-state, local-state-federal agreement over a problem with major technical, legal, emotional, and economic effects. 

RWM

 

I understand your point that railroad coal traffic will not stay the same even if a carbon policy is not enacted.  And I agree with your assessment that earth-shaking changes are not in store if a carbon policy is enacted.  Some of this stuff is oversold at first, and then settled for less.  If a new regulation tripled everyone’s electric bill overnight, the law would get remodeled.  Only so much can happen so fast.

 

As for Minnesota voters getting to where they think they are going regarding the renewable energy mandate, I doubt that many realize where they are going in that regard. Most of the boosters of the Minnesota renewable energy law will tell you that it will create prosperity.  They might tell you there will be no costs in the long run.  They really believe it will spur investment, create lots of new jobs, and be an economical win-win all the way around.  They feel that they have crafted the perfect formula for energy efficiency, renew-ability, and economic prosperity, and the quicker we change to it; the more money will be put into our pockets.  And there are a few critics who have run the numbers on the new infrastructure needed, and come up with a completely opposite picture.  If the critics are even half right, the boosters are in la-la land. 

[Paul_D_North_Jr]

Railway Man

. . .  Just the sheer economics of coal extraction, transportation, and combustion -- all current laws frozen in place -- are all pointing toward a long-term decline.  Coal is a non-renewable resource; the easy-to-extract coal is already extracted; the powerplants that burn it already built with cheaper dollars than it will cost to renew them, and so forth. 

[snip]

. . . Nothing. Has. Happened.  It's as if it is still March 30, 1979.  Nearly thirty-one years of study and debate and planning and public involvement and votes and lawsuits and dramedy and not one ounce of nuclear waste is being disposed of according to any long-term plan.  We have no plan.  . . .  the history of the U.S. is that we don't actually do anything anymore that requires large-scale, multi-state, local-state-federal agreement over a problem with major technical, legal, emotional, and economic effects.  [emphasis added - PDN]

RWM

RWM, you sure are an interesting guy to read - such as the above - some nice turns of phrase there, too. (''Dramedy'' = ''Comedy-drama, also called dramedy  or seriocomedy, is a style of television, theatre and film in which there is an equal or nearly equal balance of humor and serious content.'' - From the Wikipedia entry on ''Comedy-drama''.)

The key to your analysis is not the 'absolute' amount of change - but the relative level of change, as compared to or isolated from whatever changes are going to occur 'in the background' anyway, as in: ''Yes, it's changing, but it would change faster/ even more, if we hadn't done this as well'', etc.  As you put it - ''coal traffic is not going to increase [or decline] radically from the level it would obtain anyway.'' [emphasis added] I've been surprised by how often people - even those who shold know better - are blind to or perhaps deliberately ignore that 'take-apart' analytical step.  Sometimes if you don't break it down into cause-and-effect pieces, it becomes too easy to misunderstand or misinterpret what input is causing what output, and so on.

Finally, I know you have a high level of disdain for some of John G. Kneiling's writings - but now it seems like you might be 'channeling' him !  See:

Coal: going, going, gone
Trains, October 1967 page 37
How coal railroads can run downhill at a profit
( COAL, "KNEILING, JOHN G.", TRN )

Thanks again for your insights, as always.

- Paul North. 

[AnthonyV]

Cooter50

 Anthony, we draw a vacuum on our condenser at my plant with vacuum pumps as we start up, then leave one of three running to maintain removal of non-condensible gasses as nitrogen from the steam.  Vacuum makes a turbine run more efficiently, the steam is drawn through the turbine as much or more than the pressure from the boiler is pushing it; this in turn allows the turbine to cool somewhat as the steam has no time to linger.  Steam condensers have been around for the major life of ship engines, adding vacuum added power, minimized corrosion and aided in keeping the engine cool.  Our steady state vacuum or negative pressure is around 27" water or close to 3 lb/sq.in. absolute.

 

Hi Cooter50:

The vacuum pumps or hoggers you to which you refer are to remove the undesirable noncondensable gases (as you stated) from the condenser both at startup and during operation.

The vacuum to which I am referring is the natural vacuum that will exist in the condenser as a result of condensing below 212F.  Water condensing at temperatures below 212F will produce a vacuum, as anyone who has witnessed the crushing of a can (or tank car for that matter) by condensing steam will attest.  Clearly, the vacuum will be maintained only if the condensate pumps withdraw condensate at the same mass flow rate as the steam flow into the condenser.

 

Anthony V.

[Cooter50]

 Anthony, that is a correct statement of theory but the truth is we cannot keep our condenser/turbine shaft seal areas nor the seals on many of the valve stems with condenser vacuum upon them sealed tight enough to keep air out.  Eventually we would lose the vacuum to the buildup of primarily nitrogen/oxygen atmosphere and the system would lose efficiency to the point we would have to shut it off.  Additionally it is easier to inject corrosion control chemicals while under vacuum and they remain in solution better to mitigate iron oxide rust(red or brown) while proliferating ferric iron corrosion(black) that protects the steel components.

[AnthonyV]

Cooter50

 Anthony, that is a correct statement of theory but the truth is we cannot keep our condenser/turbine shaft seal areas nor the seals on many of the valve stems with condenser vacuum upon them sealed tight enough to keep air out.  Eventually we would lose the vacuum to the buildup of primarily nitrogen/oxygen atmosphere and the system would lose efficiency to the point we would have to shut it off.  Additionally it is easier to inject corrosion control chemicals while under vacuum and they remain in solution better to mitigate iron oxide rust(red or brown) while proliferating ferric iron corrosion(black) that protects the steel components.

Hi Cooter50:

I had hoped to reply sooner but my schedule is absolutely insane these days.  Although I don't disagree with much of what you posted, I sense we are coming at the problem from different angles.  Let me try to explain my thought process on this issue more clearly.

The way I look at it is as follows:

1) Thermodynamically, maximizing cycle efficiency requires heat rejection at as low a temperature as possible. Mechanically, this maximizes the pressure ratio across the turbines and corresponding power output (as you mentioned).

2) The earth's ambient temperature establishes the lowest possible temperature for heat rejection. Practical condenser design results in condensing temperatures in the vicinity of 100F for water-cooled condensers. Because water is used as the working fluid in all large-scale Rankine cycle plants, maximizing thermal efficiency puts the condenser into a vacuum condition by default. This is in the range of 1 psi absolute for pure water. However, the vacuum does produce the undesirable effect of air leakage into the system.

3) It is the efficiency of the condensation process that establishes the vacuum level in the condenser.  Higher condenser efficiency produces higher vacuums (and greater cycle efficiency) and vice versa.

4) For a given condenser design, the condensation efficiency is a function of a number of variables, one of which is the concentration of noncondensable gases.

5) Noncondensable gases reduce the condensation rate by lowering the partial pressure (and saturation temperature) of the steam in the vicinity of the cold surfaces. This reduces the condensation efficiency, leading to a higher condenser pressure along with a corresponding reduction of turbine power output and cycle efficiency.

6) The condenser pressure continues to rise until the partial pressure and corresponding saturation temperature of the steam near the cold surfaces is sufficient to condense the entire steam flow rate.  This process will continue as the concentration of noncondensables increases.

7) From a heat transfer point of view, the purpose of the vacuum pumps is to remove the noncondensables to maintain condensation rates closer to levels for pure steam. The need for a vacuum system arises because the saturation pressure of water at condensing temperatures required for maximum cycle efficiency is subatmospheric.

Steam volumetric flow rates into the condenser are 500,000 scfm and up compared to the approximately 50 scfm produced by the vacuum pumps.  At such high steam flow rates, the slightest disruption of the condensation process will lead to higher condenser back pressures and reduced efficiency.

Anthony V.

[Cooter50]

 Yes the steam collapse from the cooling is the end source for condenser sustained vacuum but without first establishing a vacuum we cannot maintain it, the inner walls of the systems corrode excessively due to high O2 and the raw nitrogen from atmosphere causes decreasing effect of cooling on the condenser tubing.  #s 5 6 & 7 is the key.  Yes we are approaching the same context from differing angles.

We see as little as 15-18scfm from our vacuum pumps with the efficacy of our maintenance on the sub systems but as a pump fails or trips we see condenser back pressure rise at a astounding rate and for efficiency as well as turbine longevity we are forced to trip the plant at 10" hga and rising; the main fear is we will overpressure the condenser box and cause injury or facility loss.  Power station condensers are designed to hold vacuum not pressure and definitely not steam pressures.  If our turbine trips we send the excess steam from the steam generators directly into the condenser at the tube bundles, we could theoretically bring the box to 100-500# pressure without condensing action in just a few minutes.

[AnthonyV]

Cooter50:

Thanks for the info.

 

 Anthony V.

 

 

[seafarer]

 With respect, I find it hard to believe that any large power station using steam turbines would discharge their steam to atmosphere. Such a practice would reduce the efficiency of the plant significantly and make it uneconomical to operate. Water tube boilers require very pure water which costs a lot of money to obtain by means of demineralization plants and water treatment chemicals, so the boiler water is always recycled and feed water losses are kept as low as possible to minimize these costs. In some industries back pressure turbines, designed to work without a condenser, are employed because the exhaust steam, at higher than atmospheric pressure, is used for processing purposes. Some pulp mills use this form of power generation I believe.

The cooling towers seen at power stations are for the cooling of the condenser cooling water, as others have already stated. It is this cooling water that requires steam plants to be located near a body of water, that and for supplying make up feed water for the boilers (which then has to be treated before use in the boilers). In addition to restrictions on how high a temperature cooling water can be before being discharged back into the adjacent water source, there is usually a restriction on how much water can be withdrawn from the source in a given time frame. For plants located on a sea coast, another problem encountered is fouling of the pipes that take the sea water to the plant, by marine growth. At the Milford Haven power station in Wales (four 500 MW oil fired units) the plant started off by using a regular chemical dosing schedule to kill the marine shell growth, until they discovered that the barnacles got smart and started closing their shells just prior to the chemical injection times and survived. So now they have to inject the chemicals at irregular intervals to catch the shell fish with their shells open.

I worked in a coal fired power station in the UK which was designed in the 1950s/1960s to burn coal from local coal mines. By the time the plant was operational in the late 1960s the National Coal Board had closed the local mines so all the coal had to be brought in by train from distant coal fields - 27 trains per day, five days per week. I don't know what the tonnage per train was but they were much smaller trains than you would see here in North America. In any event Ironbridge B power station had the largest coal stocking area of any power station in the UK.

This power station's overall efficiency, with two 500 MW units, was 35% and each unit consumed 600 tons of coal per hour at full load.  However, operation at full load was rarely attempted as strange things started happening to the plant apparently. The coal was crushed before being blown into the furnace in the form of pulverized coal, which acted much like a gas. Each boiler produced three million pounds of steam per hour at 2250 PSIG.The two alternators used hydrogen for cooling (the alternator casing was pressurized to 40 psig) and both the stator windings and conductors from the alternator to the first transformers were water cooled with distilled water. An interesting place to work. 

Mike Ball

[Cooter50]

 We didn't put that out that way, our steam facilities keep the water for the boiler contained and just cool the steam back to condensate adding as we must to make up for minor losses.  All the US facilities work the same fashion as your previous facility and yes they are generally sited near a cooling water source for efficacy for the condenser.  A very few use air condensers where the coolant to the steam stream is air across a boundary sheet of metal much as a radiator.  All of the facilities in my companies system run at maximum or near to max for efficient use of fuel to output and the average coal consumption is close to your old facility of near to 550-600 tons/hour but for 2400mw, a sister plant of 1250mw uses just at 300t/hr.

[seafarer]

I was actually trying to reply to Paul North's comments, in his email of January 18th, about power plants discharging their turbine steam to atmosphere. I guess I didn't go about it correctly.

Mike 

[Cooter50]

 My bad, I hadn't read all fully through!

[MP173]

Just a note to say how much I have enjoyed this thread and how informative it has been.  The vast experience of members and their willingness to share their knowledge and experiences is really appreciated.

This thread, along with the Wikipedia article on fossil fuel power plants has opened this subject up to me. A coal fired power plant was something which never crossed my mind as to how it worked.

Thanks,

 

Ed

[SFbrkmn]

The coal article I found quite interesting was reading the CSX train delevering its load to the FL power plant and the fact the crew still sits on the train while being dumped. BNSF is slowly changing over to having private contractors baby sitting trains while being dumped. This has already been done at the plants in Springerville and Coronado,AZ. An outfit called Midland Railway takes over when the train arrives at the front door and later a BNSF crew will be called to grab the empty and take it east. About two wks ago, contractors began sitting on the trains at the OK Gas & Electric plant in Red Rock, OK. I'm sure more of this is being planned at more locations.

[caldreamer]

Would natural gas and landfill gas plants be supplied by pipeline only?  I have the list of plants California and there is no inidcation as to how they are supplied.

[henry6]

The way gas companies are talking here in the Southern Tier of NY and Northern Tier of PA, pipelines are to be the means of taking the gas out of the region to market(s).

[Cooter50]

 Midland Rail unloads at our plants, in the current issue is our Labadie Plant, it receives 9 trains per week to keep the stockpile moving, burning 130-160 rail cars of coal per day.

As to natural gas or landfill methane, yes they are pipeline fodder, they do ship LNG or Liquefied Natural Gas by ship but it is a dangerous commodity to carry.  Methane or dump gas is so corrosive it must be delivered at the local level, many sites utilize plastic compound piping to move it to preclude the destruction of the piping.