Economics of advanced condensing steam locomotive

Coal is much cheaper per Btu of energy than diesel fuel or gasoline. It has a lot of sulfur and ash, that have to be neutralized and stored, but this is done routinely in power generation stations and can be applied to locomotives too.

If advanced steam turbine closed cycle condensing locomotive will reach 20%-25% efficiency, the fuel expenses can be decreased 5-10 times depending on sort of coal.

[www.eia.gov] - cost of power grade coal
[www.eia.gov] cost of diesel/gasoline

Economics of coal as a fuel for locomotives:

[ewh.ieee.org]

[www.5at.co.uk]

Coal burning locomotives with steam-Stirling hybrid engines:

[pia.sagepub.com]
[citeseerx.ist.psu.edu]



Edited 1 time(s). Last edit at 08/06/2020 07:13PM by novice.

I guess the biggest potential fly in the ointment is that, perhaps, neither system is the best option. Electricity would easily beat either alternative from the standpoint of energy efficiency and emissions --- not that I worry too much about emissions, sometimes you can go overboard. When you figure out how much pollutants are ejected by trucks and aircraft per ton/mile, i think that both trains and ships are so clean that you should try to avoid raising the cost of transporting goods that way so that you don't start to disincentivize their use.

Electric locomotives should have advantages in maintenance, ease of operation, number of operators and so on. In my trips to Japan, I was impressed by how smooth the electric trains operated and by the total lack of emissions. Like all such arguments, it can come down to which variables you want to emphasize --- I saw one analysis that favored maglev based on track maintenance costs. It was more expensive to build a maglev line but cheaper to maintain the road once installed.

On the down side, you'd have to refit all those miles of track for electric operation. But, who knows? There might be workarounds with high tech batteries --- only electrify part of the road so as to top off the battery car intermittently during the trip. Heaven knows that regenerative braking could be a good thing in mountainous terrain or on stop and go commuter routes.

Regards,

Ken



Edited 1 time(s). Last edit at 08/07/2020 05:19AM by frustrated.

Electrification of existing railroads is not cheap.
Large number of powerlines, substations have to be build along with 1000s of miles of contact wires and supporting structures.
Return on Capital investments will be decades which is not what private companies expect.
If coal-water slurry is used it is possible to use the cheapest sorts of coal and transport it via pipelines.

[www.eesi.org].



Edited 2 time(s). Last edit at 08/07/2020 12:03PM by novice.

The engines are already electric. The question is where is the electricity coming from. Currently the engines have diesel electric generators on board. Modern railroads are often electrified with overhead wires. I believe fuel cells might be a future option but so far big diesels are less expensive. Battery storage is limited to automobiles or smaller power plants, but we'll see how Tesla's big trucks do. I can't see even the most modern steam plants replacing Diesels or gas turbines. It's all a mater of costs over the power plant's life. Electric motors are hard to beat. Getting them the electricity inexpensively is the goal of current research.

I remember big steam locomotives over 60 years ago. Today a very few are still running as tourist attractions. It takes a dedicated group of volunteers to keep them operational. A long time ago I worked for a company that rebuilt one. It took big lathes and other heavy equipment, but the result was spectacular. I rode on a river steamer a few years ago as well. I videoed the engine here.

Lohring Miller

There were also projects of converting diesel locomotive engines to run directly on pulverized coal dust or ultrafine coal-water slurry. Main issue is fast wear of engine parts by abrasive coal and ash particles and corrosion by sulfur dioxide.

There is also other problem of coal locomotives - hot particles of ash and unburned coal must be cooled down to prevent fires:

[www.rtands.com]

[www.abqjournal.com]

Coal water slurry can help to eliminate this issue.



Edited 4 time(s). Last edit at 08/08/2020 02:39PM by novice.

After performing a short term gig at GE Locomotive in Erie, PA, I can say that diesel electrics (D/E) aren't all that efficient. They do have some neat features that could be parleyed into some good useful items on a steam electric (S/E) loco.

When D/E pull long consist down hill, they utilize an electric grid element (electric braking) on the top of the loco. It takes regenerative energy from the traction electric motors, braking action, and expires it as heat to the environment. Some loco companies are implementing battery storage on the D/E. The batteries would be full and excess electric dumped as heat. D/E can be equipped with third rail electric supply. If running on third rail, the excess braking energy would reverse flow to the 3rd rail. This energy is used for another loco that might be accelerating.

Let's compare to a possible S/E. An S/E would use direct drive from either steam piston or turbine. This is necessary because there is more equipment involved with a steam engine with a generator pushing the envelope over the top. One key advantage of external combustion is multi-fuel capability. Operator can hedge their bets on future fuel costs. However, the S/E would keep a bogie that is electric traction. One steam traction and one electric traction bogie. Doble actually came up with a loco steam bogie. The down hill Electric braking would go towards steam generation from the e-bogie. The s-bogie goes for a ride. Battery storage would be included with an S/E. Note that loco on rail likes a lot of weight for traction. Again, the e-bogie fills the battery during dynamic braking. A third rail shall be included and will function the same way. Note that Turbine(direct drive) Loco shut their engines off when going into the city and run entirely on third rail power. Same could be done with S/E.

A key item that helps make an S/E be competitive is external combustion. Steam injection can drastically improve energy output from some lower grade, cheaper fuels. Another thing that is near and dear to my heart is to apply HTE of the water and apply like steam injection. This plus regen-heat braking to the boiler could make this system more efficient than current options. One last thing that is typically overlooked and that is the thermal inertia in a boiler along with the on-off capability of the burner. Rail road conditions offer a variety of options for electric or steam or both steam and electric. On a cold day, you won't turn off the diesel engine and restart it again when needed. You can with a burner on a boiler.

Again, Novice brings up a good point, in my opinion. Don't think of a big boy type loco with regards to a S/E. Perhaps a boiler like a Black Staff would be more appropriate.

Black Staff Design

Since we're kicking around these ideas, this would be my approach.

Kind regards,
Rick

With modern electronics I think hybrid diesel electric power plants with battery storage will be more efficient. Apparently, so does GE Locomotive, though I don't know if they actually are going into production with the changes in ownership.
[web.archive.org]

Lohring Miller

Your thought process is correct with one caveat. My work at GE Locomotive was over 10 years ago. The battery storage concept was well known and the primary e-storage medium was lead-acid. At that time, the brake, regenerative capacity exceeded the maximum charging rate of the battery. More than 50% of the regenerative electrical energy went out the air resistor to the environment. The lead weight is attractive to the locomotive design and performance. The caveat is that the recharging capacity was not capable.

No doubt with today's battery technology, this is a no brainier. I'm sure GE has this very scenario in the works. They are probably going with just a battery locomotive or with a fuel cell generator/super capacitor/battery. Diesels are just getting too cumbersome. Too much to clean up for environmental concerns.

However, external combustion still provides clean and more fuel options. An inefficient (clean burning) fuel for low cost will be favored to a greater efficient one at a high cost.

Rick

A locomotive concept I just want to share...

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Locomotive Concept.jpg	653.3 KB	open | download	Rick.H	09/30/2020	Read message