Hi Jim
On (13 Nov 97) Jim Mcandrew wrote to Alec Cameron...
 JM> In a diesel, about 1/3 of the heat value in the fuel gets converted to
 JM> mechanical energy (- giving the efficiency rating you are used to 
 JM> seeing), 1/3 of the heat value is lost in heat to the cooling system,
 JM> and 1/3 of the heat normally goes out with the exhaust.
It would be quite a problem in MOST applications to usefully  utilise that 
/3
waste heat. Put the engine in the basement of a very large occupied building
in a freezing climate and yes, most of that 2/3 will be useful.
Transfer to application into a temperate or tropic climate [lotsa people
there!] and how on earth, would a major recovery succeed?
 JM> As a co-gen system, with the engine mounted in the space to be heated,
 JM> all the cooling system heat is recovered and a substantial portion of 
he
 JM> exhaust heat as well.  This gives efficiency as a co-gen system, as:
 JM> 33% (mechanical energy) + 33% (heat recovered from engine cooling) +
 JM> say, a 78% recovery of the heat in the exhaust - .78(.33) or 26%.
 JM> SO.. as a co-gen efficiency is .33 +.33 +.26 = 93%.
Logically I think you are describing an oil heated building with engine drive
power acquired as an auxiliary. With co-gen capability during a small part of
the year in a small part of the world!   Cheers......ALEC
... ......Pavlov Had a Dog
--- PPoint 1.92
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