A simple question

[MICHAEL WILLIAMSParticipant @michaelwilliams41215]

[MICHAEL WILLIAMSParticipant @michaelwilliams41215]

Why does a steam engine work ?

[Ian S CParticipant @iansc]

Because. Ian S C

[TerrydParticipant @terryd72465]

Why the Big Bang? Because it did!

T

[AndyPParticipant @andyp13730]

Google is your friend ! try this

[Paul BoscottParticipant @paulboscott25817]

May I rephrase the question to its more common form.

Why does a steam engine not work.

[MichaelRParticipant @michaelr]

For that matter, Why does a IC engine work when it's trying to blow it'self to bits

Mike.

.

[Jeff DaymanParticipant @jeffdayman43397]

"Why does a steam engine work ?"

'cause it has to feed the kids and pay the mortgage?

(That's the reason I work….)

Cheers JD

[Richard ParsonsParticipant @richardparsons61721]

this is like the old conumdrum 'Why is a mouse when it spins' It is not a question it is a statement which defines a spinning mouse as 'WHY'

. I am off to feed the dogs an ger a beer or three

Rdgs

Dick

[NJHParticipant @njh]

Richard

No doubt on your return from the "beer or three" you will have an answer to the question – how authorative that may be is questionable!

I'm more concerned in the answer to the question " Why will MY ***!!!***!! vacuum engine not work!

( Google didn't help with that one!)

Anyone want to make an offer for a carefully and lovingly made doorstop!

Regards

Norman

Edited By NJH on 17/03/2012 18:01:24

[wheeltapperParticipant @wheeltapper]

I'd like to make an offer but I've got so many doorstops I'm running out of bl**dy doors.

Roy

[BazyleParticipant @bazyle]

Norman. Picture? Published design?

Possibilities. Too hot to condense. Too cold and condensation too fast. Not enough volume at TDC for air content of charge. Flame not big enough to supply vapour charge.

Which came first the Mule or the Baby Mule? Well it is a simple question. And as you all know the answer why is there a problem with chickens and eggs.

[Speedy Builder5Participant @speedybuilder5]

It could be the reason why windscreen wipers only break down in the rain. I guess your steam engine does not get steam in the right place at the right time. Like most engines – its a matter of timing.

[Sub MandrelParticipant @submandrel]

The interesting question is why does a steam engine work so differently on air to steam?

Neil

[TerrydParticipant @terryd72465]

Posted by AndyP on 17/03/2012 15:08:10:

Google is your friend ! try this

That is HOW not WHY, said he, most mysteriously!!

[TerrydParticipant @terryd72465]

Posted by Stub Mandrel on 17/03/2012 19:27:05:

The interesting question is why does a steam engine work so differently on air to steam?

Neil

Hystersis

T

[Steve WithnellParticipant @stevewithnell34426]

How dare you accuse my steam engine of hysteria when running on air!

[Nicholas FarrParticipant @nicholasfarr14254]

Hi, maybe it is something to do with Newton's Third Law.

Regards Nick.

[Robert DoddsParticipant @robertdodds43397]

Hi,

As an apprentice I took Heat Engines as part of my HNC. Didn't do particularly well at it but I'll never forget the " Steam Entropy Tables" that we had to resort to to work out the power output from steam engines, turbines etc.

Its somthing to do with the energy of the water molecules in addition to the energy from the compressed gas that makes performance on steam so different to performance on compressed air .

There's a lot written on Google about Entrpy of Steam and I still can't get my head round it!

Bob D

[SteamshyParticipant @steamshy]

Hi,

Steam engines have to be warmed through properly to run, I`m guessing that as things heat up, so they expand, not all materials or parts are the same thickness either,[ not counting dissimanal metals which heat at different rates]. So maybe friction may have a bearing on why a steam engine wont run on steam but air it`s ok. Once it runs ok on steam it usually does after quite well.

I know on Large turbines prior to running there is a steam chest warming sequence, which allows the control pistons and large mass of metal in the steam chest to expand correctly,

Andy

[Sub MandrelParticipant @submandrel]

The heat difference is the key.

A steam engine is a heat engine. It gains most of its power from the steam giving up its heat to do work in expanding, something that is further improved by superheat. Air going through a steam engine has far less energy stored in it and can do far less work for the same pressure.

A steam engine can be made more efficient by adding a cold condenser to create an exhaust vacuum. If you made an air engine create its own vacuum, it would take more energy than you got out, unless it was so cold it liquified the air.

It'sa fascinating subject that I'm only beginning to understand – the likes of Watt, Woolf etc. were very clever folk.

Neil

[Ian S CParticipant @iansc]

Running a steam engine on air, could the exhaust be connected to the suction side of the compressor as well as the pressure side to the intake, would that have a similar effect to a condenser on a steam opperated engine? Ian S C

[Martin KyteParticipant @martinkyte99762]

No.

The condenser is there to transfer as much of the thermal and latent heat energy from the exhaust steam to the input of the engine. generally by pre heating the feed water to the boiler.

[Sub MandrelParticipant @submandrel]

The condensor cools the exhuast causing the stem to condense and creating a vacuum. The energy required to maintain the vacuum is very little – just that required to pump out the condensate, so it gives the engine a power boost. If you used a compressor to pump the vacuum it requires as much energy as the engine would gain.

With a good condenser an engine running light can work with the steam at less than atmospheric pressure – clearly saving energy as the water is now boiling av less than 100 degrees!

Neil

[Tony MartyrParticipant @tonymartyr14488]

Study of the second law of thermodynamics for a couple of years will solve most of the questions raised in this thread – and add greatly to the understanding of life in general

[Author]

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