The trailer power plant project, has had many challenges, in brief,
1) The test and start up use of a simplistic SU carburetor, without a exhaust
heated hotspot resulted in gasoline pooling in the intake manifold. Water
heating with tubes soldered to the Aluminum Manifold only made a hot 65deg
gasoline pool. I am amazed that the engine can run with up to an eighth of
an inch of fuel or more in the intake manifold. This undesirable situation
turns ugly when the radiator fan starts up , and the enhanced evaporation of
this pool, then causes uncontrolled richening of the mixture, and an
impersonation of the black smoke of an overfuelled Mac Truck.
2) The trialing Fuel was changed to LPG, with a vaporizer unit, and custom
made fuel mixer. This overcame the pooling , and ran ok for a week or so of
trialing the control voltage regulation, but then the Vaporizer failed(an
old unit,) and was uneconomic to have repaired.
This running had enabled the set up of the ardiuno control of the voltage
output, and revealed that this was not a suitable way to control the
throttle opening, as the "bounce" in voltage when 5kw and then 10kw load was
applied, was too much for the DC-DC converters to stay operating.
3) Returned to petrol use, with the construction of a high rise intake
manifold, so that the lowest point was draining into the intake valves. This
seemed a sure fire way to combat the pooling of fuel, which it has, BUT has
made starting more difficult, and now have turbulence issues which result in
uneven mixture to different cylinders. At this stage is easy to foul #3 plug
with carbon deposit. The use of LPG or Wood Gas, should not be affected by
this.
4) Voltage regulation has now been augmented, by using a rev dependent v
sense,to operate the throttle, and selecting at this stage 2 settings,
1800rpm or 2100rpm determined by the ardiuno program if the voltage is above
or below the target Volts of 54V. This has given relatively hunting free
speed control. The trailer is now operating autonomously, maintaining
54-55Volts, with output switching from 0-200Amps. This is now a 0-10Kw power
supply . This low voltage is carried to the drive vehicle, and at present
converted to 340-360V DC at up to 26Amps, this is capable of propelling the
Prius NHW 10 at an average speed of 60km/h on the flat, the prius pack can
then level out acceleration and short hill demands above this.
The trial run this week saw a 5km run around the block, with no operation of
the Prius IC engine in the car. Which was the design milestone I wanted to
achieve.
The Gassifier/Filter/Cooler System is now 85% complete, hopefully welding is
being completed as I write this by a helpful TIG welding friend. An
unscheduled Equipment Trouble shooting Trip is now taking me off the case
for the next weeks, so I have to suppress my burning desire(so to speak) for
a short time.
Test run heater bank 360V 5.0Kw cost per unit Nz 90cents gasoline cf to
30cents per unit I pay on the grid, plus a daily charge.
