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[FlyRotary] Re: Performance coatings- bearing damage?
Dave,
If you burn 10 g/hr, and are returning 15 g/hr to
the tanks, that is 15*6 = 90 #/hr of gasoline, with a specific heat of ~.7Btu/#,
that means you can transfer 90* 0.7 = 63 Btu/hr/degF rise in gasoline
temperature. Your coolant flow is probably about 25 gallons/minute, = 25*60 =
1500 gallons/hour = ~1500*8 = 12000 #/hour. For a 10 degree rise in
gasoline temperature you would get a 630/12000 = 0.0525 deg F drop in coolant
temperature. Doesn't seem worth it.
* note: I used rounded figures for densities and
flow rates and heat capacities. The fact remains that the flow mismatch makes
this not do much.
Bill Schertz
KIS Cruiser # 4045
----- Original Message -----
Sent: Sunday, February 06, 2005 11:46
PM
Subject: [FlyRotary] Heating the
Fuel
In
anticipation of the new turbo, I am considering ways to improve coolant
cooling. Besides the obvious more air, more ducting, more radiator; I
have been again toying with the idea of a heat exchanger. This time
coolant to fuel. The plan would be to use a typical oil/water exchanger
but use fuel instead of oil. I would use the fuel on the way back to the
tank, and the coolant after it has already been cooled by the radiator.
The fuel would then go back to the nice metal tank of the
RV.
I am
looking for input on the implications of heating the fuel. I expect it
would reach max temps of about 190 (usually a little cooler) but
quickly cool once in the tank. Can the fuel tolerate that temp without
vaporizing? It will probably expand in the tank but I don't expect that
will occur faster than it is used up. I have no guess as to what temp
will become steady state for the fuel pumped out of the tank. My guess
is that it will not be much warmer than normal, but a slight increase in temp
may help with vaporization.
The
last question is how much will it cool the coolant. My hope is about 10
deg but I doubt it will be quite that much. I know others have
considered using the fuel to cool (Tracy) and I would appreciate your
thoughts.
Dave
Leonard
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