On Sat, 23 Apr 2011 11:56:21 +0100
Jeremy Double wrote:
If what is being claimed is true - ie that heat is always required to do
work then this should be impossible.

Heat isn't always required to do work _directly_: hydro-power uses the

Exactly. Which was my point.

allowing them to do work and move the piston. Almost all of the
expansion of the combustion gases is due to the heat liberated by
combustion, not due to the increased number of moles of gas (for
instance, 1 mole of carbon burning uses 1 mole of oxygen to give 1 mole
of carbon dioxide). Remember that most of the gas in the cylinder of an
engine is nitrogen from the charge air (air is about 79% nitrogen).

That doesn't matter - 1 mole of CO2 at room temperature takes up vastly
more volume than 1 mole of liquid a hydrocarbon. If all the reaction did was
to heat the air in the cylinder up by 500 hundred degrees and didn't produce
any extra gas then very little would happen. The same applies to a steam
engine - you don't heat air up and shove hot air into the cylinders, you need
to convert a liquid (water) into a gas (steam) to get work out.

B2003