The future of rail could be this 75-year-old steam locomotive

A trawl of the interweb threw these up ......

Torrefaction - Wikipedia, the free encyclopedia

National Energy - Specialists in Biomass Fuel - Biocoal

There's plenty more info out there if you search for it.

 

there are preserved engines that are already wood fired:

Florida Wood Burning Steam Train - YouTube

The issue with timber isnt temperature but output. MJ of wood is about 1/4 that of coal so you would need a lot of timber (and a pretty big ashpan for all the ash)

Duncan

 

I was impressed by the promised thermal side of the 5AT project but had doubts about the mechanical side. However, if they thought that one could get 180kph with a 800mm stroke and 1880mm drivers then 210kph from 749mm stroke and 2134mm drivers isn't much different.

As for economy, if one can get biofuel of the same thermal value as coal at a fraction of the cost then it will be viable, but that seems a big if.

 

This wood burning stuff is all very interesting, but it's not what the OP is about.

They're talking about 'Bio-Coal' or more correctly 'Torrified Wood' which is thermally modified and then compressed into something resembling coal briquettes. These can then be hand or stoker fired, or pulverised and fed into power stations as PF.

 

From a thermodynamic and mechanical point of view pretty much with you there. You have to burn something for a fire, and from that operation pretty much 85% ( within the loco ) is waste propduct.

These briquettes have to be produced, and the efficiency of the process overall, growing collecting processing to produce them has to be included in the overall thermal efficiency of the operation of the loco.

As Gaurd Jamie identifies, burning on a much larger scale, at a power station, can get consistency of process monitor burn condition, within the grate to obtain max efficiency and claw back waste heat for other processes, after the steam heat is spent.

Even with the most advanced nat gas burning power stations this thermal efficiency is only reaching about 34% the rest goes as waste into the atmosphere.

Natural coal powered steam engines only acheive a transfer efficiency just over 10% without considering build and operational cost even the most advanced design rail loco's don't acheive 15% conversion raw fuel to work done.

 

Another one bites the dust.

Shame to ruin an interesting looking locomotive.

 

I concur with you Skip- but this could be the future.

 

Sorry Saggin' I meant the future for this loco-it's all very interesting. You can follow progress on US railway writer Fred F Frailey's twice weekly blog on wwwTrainsMag.com

 

Re: Another one bites the dust.

What exactly do you see as ruining it?

 

Not an engineer, so can't/won't comment on the mechanics of it all - but what about practicality? Are any Railroads in the USA going to let the thing run at 130mph mile after mile (if attaining it is possible, how is it sustainable in terms of keeping the high speeds?), particularly as I was under the impression many of them aren't that steam locomotive friendly in the first place?

 

The future of steam engines is already here and that isn't it. They are sat in very large buildings all around the country generating most of the electricity we use today.

 

Indeed...

For thermal efficiency, you need the largest possible temperature difference between the inlet gas (e.g. steam) and the exhaust. The necessity on a conventional steam engine to still have some exhaust velocity (in order to clear the cylinders and provide a draft) means the exhaust temperature is rather high; certainly well over 100C (maybe 400 Kelvin). Whereas the necessity to have a relatively light boiler means working pressure can't be too high and therefore the inlet temperature is not that high - typically only around 200C (maybe 500 Kelvin max). The maximum possible cylinder efficiency at that point then becomes 1-(400/500), or 0.2 (20%). By contrast, an efficient steam turbine with high pressure (= high temperature) input and condensing output (= low temperature) can have a way higher theoretical efficiency; and moreover can be optimised under normal operating conditions to actually approach the theoretical limit much more closely than a steam locomotive.

And that's just for starters: the inefficiency of combustion becomes even worse where you can't optimise the airflow in any reasonably practical way. 4/5 of all the air drawn through the fire is nitrogen that is simply heated up and thrown away up the chimney at a few hundred degrees C. The same happens in a power station, of course, but the airflow can be very closely controlled so that just the right amount of air is drawn through and no more. Whereas on a steam locomotive, the efficiency penalty by having too little air (due to incomplete combustion, e.g. throwing unburnt fuel up the chimney) is so great that generally engines are worked with too much air; but running with perhaps 20% more air than needed to be on the safe side is throwing away colossal amounts of hot air up the chimney.

So I'm afraid this is a non-starter and pure romantic tosh on any sensible basis of minimising carbon emissions. Of course it is entertaining to know that in a free-market economy, apparently sensible people are entirely capable of throwing money away on the basis of romantic whims - literally throwing money away onto a fire.

Tom

 

Hence my comment "Of course it is entertaining to know that in a free-market economy, apparently sensible people are entirely capable of throwing money away on the basis of romantic whims". Indeed, I have myself given large amounts of money into the romantic whim of moving domestic waste from Sussex to Oxfordshire - but not because I think it somehow solves the nation's underlying problem of lack of landfill capacity. Similarly, I have no problem with people backing this project provided they are going in with their eyes open about the underlying thermodynamics. But I would worry if people were investing cash they actually needed thinking they were going to make any kind of financial return...

Tom