tomikawaTT It would also be possible to incorporate ideas from Andre Chapelon (improved steam flow and exhaust ducting, Porta (gasifier firebox) and others to improve and clean up the steam generator (boiler.) Control of stack emissions might require a whole new level of inventiveness, but it can be done.
It would also be possible to incorporate ideas from Andre Chapelon (improved steam flow and exhaust ducting, Porta (gasifier firebox) and others to improve and clean up the steam generator (boiler.) Control of stack emissions might require a whole new level of inventiveness, but it can be done.
Should I start a new thread on "combustion processes" or would that result in the TLDR and MEGO effects?
I was doing some Web surfing on "boilers" and "coal combustion", kinda to see what the "rest of the world" is doing when they want to burn solid fuel to raise steam.
It isn't just trains, ships of various kinds, with the possible exception of the SS Badger lake ferry that is not only steam, it is reciprocating steam, and I don't get a whole lot of love for mentioning this, the EPA, motivated by every environmental group, is breathing down their neck about discharge of coal ash into Lake Michigan. Yes, people drink the water and catch the fish, and I have done all of those things and yes, they should figure some way to not dump the ash, but that the SS Badger is the last of its kind and a piece of our industrial heritage doesn't influence some people. Heck, when the Soo 1004 last came to Madison, there was a torrent of angry letters-to-the-editor about the environmental damage.
So steam propulsion is really almost gone, everywhere, so who needs a boiler? Well, there are still a lot of coal-fired electric power plants, and even those new high-tech gas-turbine gas-fired plants use "bottoming cycles." OK, who else.
It seems that everyone and anyone who wants to burn some fuel "over here" in order to supply some heat "over there" uses boilers to raise steam -- central heating plants as for campus buildings at the "U", various kinds of commercial and industrial applications, and so on. So boilers of all sizes and shapes and pressures and ratings for various applications aren't going away anytime soon.
So what are the combustion systems. Lately, natural gas seems to be the answer. The "U" converted the Charter Street central plant to gas, which raises steam to heat the buildings in summer and provide chilled water for A/C in summer -- I guess they use steam-ejector chillers? The MGE Blount Street electric plant also is scheduled to fire its boilers on natural gas -- I am told they are shuttering their 900 PSI boiler and keeping only their more efficient 1200 PSI boiler after the conversion.
As I have been reading up on steam locomotives and steam power, the two main coal combustion boilers in town are no more, especially since I am learning from Wardale and other readings what questions to ask about how these boilers operate but coal combustion and maybe even the people to answer those questions are being retired.
OK, I get the sense that "the big boys" use pulverized coal combustion. The coal is ground up to the fine consistency of face makeup and then blown into the firebox with compressed air, where it burns like a gas flame -- there is little smoke, no cinders or "carbon carryover" to lower efficiency. But much if not all of the coal ash with its lung-harming micro silicate particles and fish poisoning mercury goes up the stack, that is, unless they use some kind of stack gas aftertreatment.
The "not quite as big boys" (the Charter Street plant -- never did get to find out) use a variety of methods, including Fluidized Bed Combustion. I don't get the sense that Fluidized Bed Combustion is any time ready for steam locomotives as it takes a day-long startup procedure to get stabilized.
If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?
Well boys, you know steam engines ARE being built today by the Kloke Locomotive Works.
However, they look like something from the 1860's!
Better than no new steamers at all!
www.leviathan63.com
Firelock76No steam-turbine-electric? I don't know, the Norfolk and Western's "Jawn Henry" got pretty close. It did have its bugs, but those could have probably been worked out if the experiment had been continued.
I thought so too, until I read Louis Newton's book. The turbine-electric part was the disaster, apparently, with improperly-designed auxiliaries being a contributing factor. Sure, all those details could still have been fixed, but you'd still have only a 4500 hp constant-power locomotive, incapable of making substantial power at high speed, and probably reflecting a tradeoff between limited power at instantaneous/hourly rating at low speed vs. traction-motor longevity.
Minimum modern design size for a turbine-electric under modern conditions is nearly 9000 hp. The B&W water-tube boiler will not scale to that number; in fact, according to Tom Blasingame (who ran the numbers) it won't even scale cleanly to 6000 hp without detail redesign.
I still think there is a place for mechanical-drive steam turbine power... but a limited and circumscribed one.
In my opinion, a "modern" steam locomotive will either resemble a longer version of the FRA ALPS locomotive (with a gas-turbine combustor feeding a combined-cycle steam bottoming plant) or will use ultrasupercritical steam motors (again with extended Rankine-cycle heat recovery bottoming). Neither of these will use 'conventionally' recognizable boilers, although I do expect them to use some form of condensing or Holcroft-Anderson 'recompression', and take other measures to minimize the effective water rate (for the purified water used in high-pressure cycles).
There may be a place for 'second generation steam' using a more-or-less familiar reciprocating configuration. I would NOT expect this to follow the wonky premise of the ACE that steam has to be 'hidden' to be taken seriously in a modern context. On the other hand, a very clear and detailed case, showing all the ancillary details, would need to be made for this kind of power if it is to be competitive with modern diesel-electrics, or straight electrics in those areas where the necessary power infrastructure can be built. Very little has changed since the Porta SGS designs, and David Wardale's Red Devil, were made.
I am not a particularly strong supporter of the Withuhn conjugated drive. It has a great deal of theoretical merit, but once it is actually buiilt with suspension (as any practical locomotive would be) there may not be enough advantage to justify the considerable added complexity (and the difficulty of providing axle bearings on the mains, which have to provide the double cranked axles for the conjugating rods). There are also the problems associated traditionally with rear-mounted forward-facing cylinders -- many of which can be solved, but some of which have endemic problems.
On the other hand, by the time of the late '40s the available power from even a two-cylinder engine was producing substantial stress in main pins at any sort of true high speed. That was, and is, a major reason to favor a divided-drive arrangement. I happen to believe that a nonsynchronous method of conjugation is preferable (and have described it to a certain MEGO level) but it is beginning to appear as if conventional methods can provide most of the benefits of duplex conjugation without the, er, actual conjugation. Traction control via the independent-brake mechanisms is one approach with promise.
It is entirely possible that a 'duplex' for general service might require only two-wheel lead and trailing trucks. I do think that larger grate area is preferable even when competent Rankine-cycle optimization has been done elsewhere (a la Chapelon, Porta et al.) and therefore a four-axle trailer (principally for weight-carrying) would continue to be used. We've been over much of this ground in Juniatha's past threads on modern steam evolution.
I would not be surprised if they looked very much like diesel locomotives do today. When the turbines showed up they were very similar to diesels of that time, the exception of course being the PRR version.
chutton01 I tend to think that they could use adaptions of the engine-->generator-->traction motors base design of most Diesel-Electric locomotives out-there. Heck, keep things modular enough, in theory you could use any power unit that uses any source of fuel that can run the generator and drive the wheels (for non electric locomotives)I don't think you'd want designs with external piston rods direct-driving the wheels (pretty much the traditional design of steam locomotive - although admittedly the cool reciprocating action does makes a steam locomotive rather interesting - as AFAIK rather heavy steam locomotives really pounded the heck out of the rails - ah, the wiki entry calls it "Hammer Blow"
I tend to think that they could use adaptions of the engine-->generator-->traction motors base design of most Diesel-Electric locomotives out-there. Heck, keep things modular enough, in theory you could use any power unit that uses any source of fuel that can run the generator and drive the wheels (for non electric locomotives)I don't think you'd want designs with external piston rods direct-driving the wheels (pretty much the traditional design of steam locomotive - although admittedly the cool reciprocating action does makes a steam locomotive rather interesting - as AFAIK rather heavy steam locomotives really pounded the heck out of the rails - ah, the wiki entry calls it "Hammer Blow"
Withun has that proposal for a "conjugated duplex" that required a pair of crank axles, although it is argued that this linkage between the two sets of drivers would not be called upon to transmit the full torque, just enough torque to keep the two sets of drivers rolling the same way.
The Pennsy S-2 turbine had quill drive to one or two drivers and then siderods to the others, and siderods without having to balance reciprocating forces was not that bad an arrangement. I believe a Swedish turbine had a jackshaft drive as used on many of the early electrics before they made the motors much smaller. The turbine turned a dummy driver, and that driver was linked to the real drivers contacting the rails with siderods, and that too did away with the reciprocating forces.
I have been wondering of a high-speed multi-cylinder steam piston engine could be coupled to the wheels with that same electric-locomotive style jackshaft drive. Actually, this invention is credited to Thomas Crampton, of the "big wheel" steam engine that was popular in mid 19th century France for express passenger trains.
But is the hammer blow and "dynamic augment" really that big of a problem? There were undoubtedly cases of some small-drivered 2-10-0 or 2-10-2 with bad balance to begin with, run too fast downgrade and damaging sections of track. Everyone keeps saying that the "steam locomotive pounded the rails", but if it were such a problem, wouldn't 3-cylinder and 4-cylinder "balanced drives" using cranked axles been much more popular?
No steam-turbine-electric? I don't know, the Norfolk and Western's "Jawn Henry" got pretty close. It did have its bugs, but those could have probably been worked out if the experiment had been continued.
But it wasn't. Missed opportunity? No, not with diesels coming anyway.
A rod-driven locomotive could employ the Withuhn modifications to greatly reduce the dynamic augment - what that Wiki entry was referring to. It would also be possible to incorporate ideas from Andre Chapelon (improved steam flow and exhaust ducting) Porta (gasifier firebox) and others to improve and clean up the steam generator (boiler.) Control of stack emissions might require a whole new level of inventiveness, but it can be done.
The one thing I wouldn't expect would be a resurgence of the steam turbine electric. The operating characteristics are fine for constant speed but suffer badly when the speed departs from the optimum. Also, unless locomotive suspension systems have improved almost beyond belief, the operating environment is far from ideal. Turbines are good in fixed power plants and aboard ships, but only a ship in combat begins to approach the abrupt movements ordinary slack action can impose on a locomotive.
IMHO, the biggest obstacle would be financial. Initial development and prototyping would swallow $$$, with no guarantee that some future Congress will never chop the idea off by legislative fiat. Or some mad scientist might team up with a sane engineer and perfect a little box that eats used cat litter (or anything else equally worthless) and produces 650VDC, ready to feed to the AC drive controllers and the skewed squirrel cage traction motors.
Somehow I think that change, when it comes, will come quickly - and from an unexpected direction.
Chuck (sometime SF author)
The problems of emissions controls would really affect the design. I suspect that coal fuel would be out, and a rather complex oil firing system would be required.
Jim
Modeling BNSF and Milwaukee Road in SW Wisconsin
If someone was to create a steam locomotive with today's technology, what would it look like?
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