Dave,
In current return systems, returning the fuel
from the fuel rail alone to a header tank is a NO! NO!
The residual heat in a small fuel tank isn't
sufficient to cool the fuel before it goes back into the fuel rail - it
causes vapour lock.
All return fuel, I have been told , must return
to the much larger tanks to dissipate the heat
The Wankel Rotary which has fuel cooling
the rotors is suspect in this regard. I have no facts on this, only what has
been discussed on other sites.
Given this information I believe you may have a
considerable problem with heat.
George ( down under)
Sent: Monday, February 07, 2005 3:46
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