| Varimax Engine Test to Determine The Effect of
FPC® Upon Fuel Economy and
Power Output by Western Australia Institute of Technology (WAIT)
Abstract
An extensive study by the Western Australian Institute of Technology
(WAIT) collected considerable data demonstrating the effect of the FPC®
catalyst on engine efficiency and power output while operating at varying engine speeds
(rpm), engine loads, and injection timing. The test was designed to best illustrate the
effectiveness of the FPC® combustion catalyst. In addition, the test
conditions were aimed at determining the effect of the catalyst on the most commonly
altered settings and conditions encountered during normal field operation of heavy-duty,
compression-ignition engines.
Background
The objective of the WAIT study was to determine the effect of the FPC®
burn rate modifying combustion catalyst on engine brake power and brake specific fuel
consumption. In order to considerably broaden the scope of the test program in terms of
relevance to simulating true commercial and industrial operating conditions, the following
parameters were introduced to be varied accordingly:
(1) Engine speed
(2) Throttle setting
(3) Fuel Injection Timing
(4) The concentration of
the catalyst in the diesel fuel
The manner in which each parameter was altered is described below:
* Engine speed
in all tests was varied from 1600 rpm to 2400 rpm by increments of 200 rpm.
* Throttle
settings were altered alternatively from half throttle to full throttle in the majority of
the tests.
* Fuel
injection timing was varied from 18 degrees before top dead center (BTDC) to 42 degrees
BTDC, in increments of 6 degrees, in specific tests. The standard injection timing was 30
degrees BTDC.
* The
concentration of the catalyst in the diesel fuel was altered by employing three different
mixing ratios.
Engine base parameters held constant during the entire test program were
compression ratio, and valve timing. The compression ratio was 18:1. Valve timing was set
to the engine manufacturers' recommended values for the test diesel as is listed below:
| INTAKE VALVE |
OPENS 10.8 degrees BTDC |
|
CLOSES 42.6 degrees ABDC |
| EXHAUST VALVE |
OPENS 7.6 degrees BBDC |
|
CLOSES 21.6 degrees ATDC |
| VALVE OVERLAP |
= 32.4 degrees |
Baseline tests using untreated fuel were conducted at the beginning,
middle, and end of the test program to check whether any drift in the engine performance
had occurred due to the introduction of the combustion catalyst.
Test Method
The commencement of a new test, with the engine in a cold state,
involved a set procedure. This procedure was strictly adhered to. From initial start up
the engine was run at part throttle for five minutes, and then slowly brought up to full
throttle in thirty seconds. This insured a gradual engine warm-up. The warm-up period was
continued until the engine temperature reached 65 degrees C.
With the baseline tests, testing commenced once this temperature was
reached and remained stable. Testing of the diesel treated with FPC® catalyst
commenced after a engine preconditioning period. The preconditioning or delay period
before actual gains in horsepower and fuel economy are witnessed had been observed in
previous test programs with the catalyst, and in prior studies by WAIT.
Once testing commenced, the following readings were recorded during all
tests:
(1) Brake torque
(2) The time required for the
engine to consume the fuel contained in a 48 ml pipette
(3) Exhaust
temperature
(4) Ambient
temperature
Five readings of brake torque and the elapsed time for the consumption of
48 ml of diesel fuel were recorded at the various speeds. All readings were subsequently
averaged and a mean value was recorded.
Discussion
An interesting anomaly was noted at the start of the tests involving
the introduction of the combustion catalyst into diesel fuel. The anticipated gains in
power output and fuel economy did not occur until after a period of engine running. This
anomaly, which had occurred in previous test programs, is often called the engine
preconditioning period. Its cause is not fully understood, however a possible explanation
will be outlined here.
The preconditioning period may be related to the time required for the
combustion catalyst to react with, and slowly remove carbon deposits present on the
combustion chamber surfaces. The lack of immediate power output and fuel economy
improvement is probably due to the reaction between the active ingredient and the carbon
deposits proceeding, instead of the intended reaction between the active ingredient and
the diesel fuel. It appears the catalyst may have a greater affinity for pure carbon
particles than it does for hydrocarbon molecules and radicals.
Once most of the carbon deposits are removed from the engine's combustion
chamber surfaces, the catalyst is free to react with the hydrocarbon molecules and
radicals in its normal and intended manner. Gains in power output and fuel economy follow
accordingly.
Throughout the Varimax engine test program, engine speed, throttle
setting, injection timing, and catalyst concentration in the fuel were all varied to
examine the effects of the combustion catalyst on the combustion process. Since the
probable mode of action was to increase flame speed, confirmation of this was required in
all tests.
Under all engine conditions that tend to slow flame speed, the FPC®
catalyst showed greater effect than when the Varimax engine was tested at optimum
injection timing, engine speed, throttle and load. Further, as the concentration of the
catalyst was increased in the diesel fuel, greater improvement was observed. All of these
facts support the theory that the FPC® catalyst effects flame speed. Also, the
catalyst will have a more profound impact upon power output and fuel economy in engines
operated in the field where transient phenomenon create slower flame speeds, and greater
combustion time losses.
Additionally, the observed engine preconditioning period or reaction with
existing combustion chamber deposits would be expected to add to the effectiveness of the
catalyst under actual field operation since carbon residue tends to reduce the efficiency
of an engine over time. Deposit removal from piston crowns, injectors, and ring zone
areas, would restore the engine to like-new operating efficiencies.
It stands to reason then, the combined effect of FPC® catalyst
removing engine deposits and the speeding of flame propagation when engine operating
conditions are more transient, such as in commercial and industrial engines, would cause
greater improvements in power output and fuel economy (bsfc).
Conclusions
The Varimax engine test program has shown quite convincingly the
benefits of FPC® catalyst in diesel fuel. At the highest catalyst
concentration in the fuel, bsfc improvements ranged from 1.71% to 4.99%, with an average
improvement of 4.19% at half throttle and low torque, 3.04% at full throttle and high
torque, and 2.61% at full throttle, high torque, and 2400 rpm while varying injection
timing from 42 degrees BTDC to 18 degrees BTDC.
Even though the test was designed to more closely reproduce actual field
operating conditions than was possible in other methods, the engine was still tested at
steady-state. Steady-state operation tends to minimize the potential for improvement from
the use of a burn rate modifier. FPC® products use under "real life"
conditions (transient operation) will create even greater benefits in terms of fuel
economy and power output. |
