A not very close analogy would be on steam locomotives (particularly
North American ones) where part of the heat from the exhaust steam
was recovered by a heat exchanger (called a feedwater heater)
where it pre heated the feed water going into the boiler. However I
don't think there was much danger of the relevant parts melting !
This system was also used in France but not much in Britain, where
boilers were mostly fed not by pumps but by injectors ,
themselves a demonstration of the conservation of energy in the
conversion from steam pressure to inertia of the water and back to
water pressure, but these require cold water feed; the Great Western
type exhaust steam injector fulfilled this function to some degree
though.
Hope this helps
Peter D Hingley, London, England
-----Original Message-----
From: Promoting discussion in the science studies community
[mailto:[log in to unmask]] On Behalf Of Jeff Hughes
Sent: 21 January 2010 10:58
To: [log in to unmask]
Subject: Query: transpiration cooling [Scanned]
Hi all -- if anyone can help Rachel with her request (below), please
contact her directly at [log in to unmask]
Thanks / Jeff
>I am a researcher on an engineering documentary about the US space
shuttle. I am looking into their engines which are amazingly efficient
and this is partly to do with regenerative cooling. This is the flow of
fuel around the main combustion chamber in order to cool it sufficiently
and not let it melt, the heat is drawn from the combustion chamber into
the fuel which heats it slightly. It is this fuel that then goes into
the engine to combust and so the energy is conserved. We are looking
for earlier analogies to this - so early engines/kilns/anything (!) that
has some kind of cooling system (either water or air) flowing around the
engine to draw excess heat away. Any ideas would be much appreciated.
Many thanks,
Rachel Millar
Researcher
Engineering Connections with Richard Hammond
Tel: 02074827027
Mob: 07792749730
|