Electric steam engines, the future!

Has anyone tried an electric steam engine miniature, would it be feasible?

Edited By Cyril Bonnett on 24/02/2023 14:39:16

Edited By Cyril Bonnett on 24/02/2023 14:50:04

I've seen a few builds of electric elements in boilers which seemed to work well. Also hidden motors to turn over "steam" engines for display purposes.

Jensen in the USA have offered electrically heated boilers on their steam models for over 60 years.

http://jensensteamengines.com/hobby/h70g.htm

Blondihacks on youtube recently built a boiler with an electric element for heat. A cartridge heater with integral male pipe thread fitting was used. These heaters are probably the simplest way to implement electric heating for boilers. Sealing and mechanical fastening is done on pipe threads and all electric wiring is on the dry side. Many industrial suppliers offer cartridge heaters.

Hornby made a Mallard with real live steam from an electric boiler. 00 gauge.

Edited By Bazyle on 24/02/2023 16:27:36

Storage radiators heat the bricks to well above 100C so one could use solar panels to heat that then run a steam generator off that for overnight electricity. A stirling engine might be more user friendly for the general public and the dreadful inefficiency wouldn't matter so much if you were using the heat for house heating too.

I used cartridge heaters for many applications when I was working and in order not to have any 'leaking' problems I fitted the in a pocket

H

At the Doncaster show there was a layout upstairs, electrically powered steam train, it picked up the electricity from the track as it went along, very nice it was too. John

Roughly, and we all know how bad my maths is:

IMLEC shows engines get about 200W out at 2% efficiency, in which case the fire generates about 10kW of heat.

In a typical steam locomotive about 60% of heat from the fire escapes up the chimney.

An electric boiler wouldn't need a chimney, so a 4kW element enclosed inside a boiler would produce much the same usable heat as a 10kW fire - a big increase in efficiency.

However, although heat loss up the chimney is saved, the steam engine is still only 5% efficient, wasting 3.8kW of the 4kW input. That's dreadful compared with using the same quantity of electricity to turn an electric motor rather than boil water to make steam to drive pistons.

As an electric motor will be at least 60% efficient, a battery capable of supplying 4kW will put 12 times more power on an electric train's wheels than the same input used to drive a steamer. 2.4kW on the track vs 200W. And the story doesn't end there: an electric locomotive wastes no power when stopped, and can recharge the source a little when it brakes. A less obvious but vital advantage of full-size electric locomotives is that they out accelerate steam by a factor of 5 or 6. Electric trains allow about 5 time more traffic to be carried on a track previously worked by steam. Tracks that don't have trains running on them waste money, and the extra capacity is very important on busy commuter lines. Not to mention electric not filling underground railways with heat and smoke.

Steam locomotives look and smell wonderful, but they only make sense when large amounts of cheap coal are available and the dirt doesn't matter. Otherwise, they have a long list of disadvantages. If labour is cheap they're relatively simple to maintain, but availability is low; steam locomotives they spend most of their time being maintained rather than earning money by hauling traffic.

Dave

Edited By SillyOldDuffer on 24/02/2023 17:55:47

Wilescos D32 was an electric heat model, has a micro temp hidden on the end of the boiler as a fail safe ! But if it fails it is not a spare part, one needs to know what it is and what to do to replace it. Noel.

For real verisimilitude you should build a steam-power turboalternator fuelled by coal to generate the electricity to power your boiler element.

The Swiss produced a full sized electrically fired steam loco to deal with their lack of coal during the second world war.

The Swiss Electric-Steam Locomotives.........Lasik (douglas-self.com)

Beware of the Douglas Self site You can get lost in there for hours (days).

I believe injection moulding machines use cartridge heaters in their moulds, that might be a place to start looking.

Jim Ewins measured the efficiency of model loco boiler at about 70%, so SOD is being pessimistic. Having said that I would imagine a 3kW electric fired boiler would be good for running stationary engine for display.

Back in the 1930's there was an article in ME about an electrode boiler, just pass current through the water, no heating element. Someone posted it here recently, but I can't find it. A bit dodgy unless you had an isolation transformer and could ground one end of the shell of the boiler

Roger B beat me to it.

There was a photograph of a little shunting loco with a pantograph on the cab roof!

Howard

Long long ago I made a simple oscillating steam engine from a car brake cylinder. This was coupled to a bike dynamo and a small light bulb. Steam came from my mother's pressure cooker on an electric cooker. Input heat around 2kW. Light bulb 6V 0.5 A 3W. Efficiency negligable

Oil refineries used to have fireless steam trains. They would charge the train with steam from a stand pipe supplied by a remote boiler.

Some here may recall Ron Jarvis' wonderful models of significant early steam-engines of various types, parallel in individuality, technical significance, quality and medal-magnetism with Cherry Hill's models. They did know each other, via the major exhibitions.)

If so, you may remember his Newcomen Atmospheric Engine - a sizeable model approaching two feet high as I recall.

He made all its correct, scale, lead pipes, timber framing, "stone" blocks or bricks for walls (very probably cast and laid individually, not engraved slabs), wrought and cast "iron", square fasteners and the like; but realised he could not reasonably coal-fire the partly-spherical boiler, 2psi w.p. as original. It is about the size of an orange - and dimpled like one to represent the hand-forged iron plates, though actually of copper or brass.

So Ron, a retired Civil-Service Scientist who taught himself computing when using computers meant knowing computers not just using them, decided on something that could not have come to Newcomen... electricity.

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Therefore the boiler contains a small, low-voltage electric element, controlled by a temperature probe and an integrated circuit discreetly concealed in the machine's base. The on-off switch and I think a small temperature or pressure meter (electric), are set into a panel in one side of the plinth.

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I do hope this and his other works have found a proper home where they can be appreciated; but I remember Ron would joke about this being the only example of an Eighteenth-Century Atmospheric-Engine with Computer-Control!

Mentioning electrode boilers.

The prototype Rolls Royce DV8s were endurance tested by driving an alternator supplying an electrode boiler that produced heat for the offices at Shrerwsbury.

Howard

A replacement electric shower element would be a good starting point. Most are dual rated or a simple phaseangle "dimmer" would woork well. Get a small one though. 3kW limit on a 13A plug.

Robert.

A replacement kettle element may be better, being designed for the higher temperature. Whether it would stand the higher temperature still, at engine pressure, I would not like to say.

Possibly OK for a small stationary engine working at a modest 25 or so psi.