1.0 Program
Evaluation of the effects
on vehicle emissions and fuel consumption of an after market in line fuel
conditioning device.
2.0
Objective
To evaluate the potential
benefits for the environment of an after-market device added to the fuel
delivery system of a postal step van. The test program includes laboratory
measurement of vehicle emissions and fuel consumption without and with the
device on an urban driving cycle, at + 20° C.
3.0
Participants
The Tadger Group
Environment
4.0
Test vehicles
3 Postal step vans
supplied by Canada Post
Model: 1992 Grumman P-30 GM chassis
Engin: 6.2 litres diesel
Transmission: 4L-80E
automatic transmissions
5.0
Test Fuel
305 ppm sulphur, standard emission test fuel
6.0 Test
Procedure ……………..CFR 40 Part 86
1.
Canada Post supplied the test vehicles. The vehicles
were being pulled out of postal service and went through regular preventive
maintenance (oil change, oil and fuel filters replaced etc..) prior to the
baseline testing.
2. Then vehicles were tested in
laboratory
3. The fuel was replaced by standard
commercial test fuel and driven on the dynamometer over two preparation test
cycles.
4.
The
vehicle was driven on the dynamometer over one urban test cycle at + 20°C and
left to soak at + 20° C until next day.
5. Next day push the vehicle on a chassis dynamometer
simulating inertia weight and road load horsepower and perform a cold start
urban test cycle. The measured pollutants are Carbon Monoxide, Carbon Dioxide,
Oxides of Nitrogen, total Hydrocarbons and particulate matter. Fuel consumption
is also measured using the carbon balance method.
6. The above tests step 5 is repeated on 3 consecutive
days.
7. This first set of test result will serve as the
reference database (base-line), which will be used to compare the device
performance.
8. Next step is
the installation of the device by Canada Post.
9. Put the vehicle back in postal service for a 45-day
period.
10. Then repeat
steps 3 through 9.
7.0 Facility and Equipment Description
The equipment for this test program consists of
an environmentally controlled vehicle test cell containing a light duty vehicle
chassis dynamometer and a corresponding exhaust emissions sampling system and
analyser bench. This test instrumentation complies with the set-up requirements
for light duty vehicle exhaust emission compliance testing as designated in the
Canadian Motor Vehicle Safety Act (CMVS).
8.0
Gaseous Emissions
Measurement and Analytical Instrumentation
The constant
volume sampling system[1], also referred to as a
dilution tunnel, was used for the vehicle exhaust sampling. Gaseous exhaust
emissions were drawn from the tunnel using a venturi
probe and directed to the sample bags.
A second
probe, in the same area as the gaseous probe, is used to direct a sample from
the main tunnel is drawn through 70mm Teflon coated glass fibre filters for
particulate matter (PM) collection.
The gaseous
exhaust emission analysis bench consists of at least four separate analyzers
for determining the gaseous concentrations of the exhaust components.
The emission
rates of total hydrocarbon (THC), carbon monoxide (CO), carbon dioxide (CO2),
and oxides of nitrogen (NOx) are
determined by collecting a proportional sample of the dilute exhaust in Tedlar® "bags" and analysing the contents of the
bag using a Flame Ionization Detector (for THC), Non-Dispersive Infrared
instruments (for CO and CO2) and a Chemiluminescence
instrument (for NOx).
Fuel consumption was determined by the carbon balance method used
throughout the industry.
9.0
Chassis
Dynamometer Description
The chassis
dynamometer test cell and instrumentation is designed to replicate the typical
forces exerted on a vehicle while it is driven on the road while controlling
all of the extraneous variables (e.g. driving style, wind, traffic flow,
ambient temperature), that could have a significant impact on the vehicle fuel
consumption and exhaust emission.
The exhaust
emission chassis dynamometer has the capability of simulating both road load
power (RLP) and the inertia weight (IW) of the vehicle.
The road
load power is the power required to maintain a given constant vehicle speed on
a level road without any wind. The dynamometer simulates this power required to
overcome the normal mechanical and air drag of the vehicle.
Vehicle
inertia weight or simply inertia is the term used in the industry to describe
the forces on the vehicle during acceleration and deceleration due to the
vehicle mass. The term was derived from the inertia of flywheels used in
chassis dynamometers to simulate the mass of vehicles. Each flywheel was designed
with an inherent mechanical inertia or a resistance to a change in rotational
velocity. Several flywheels with different inertias are clutched together to
simulate the mass of the vehicle. Current all electric chassis dynamometers use
a combination of permanent flywheels and electric motor control to simulate the
mass of vehicles under acceleration and deceleration.
Control of
the vehicle load is controlled by an electronic dynamometer controller that
continuously adjusts the forces, (RLP, inertia weight) exerted on the vehicle
based on the initial input parameters and the indicated vehicle speed.
The chassis
dynamometer used for this test program was a light duty vehicle dynamometer
with single 24 inch rolls per axle, an electronically controlled direct current
electric motor that simulates the vehicle road load power and vehicle mass.
This chassis dynamometer has the capability to simulate between 1000 and 10 000
lbs of vehicle mass and up to 50 hp of RLP.
The rotating speed of the
dynamometer roll during a vehicle emissions test is measured by a pulse
counter, which communicates this information to a microprocessor controller.
The controller translates the pulses into the linear speed of the vehicle and
that speed is displayed on a video screen as a cursor. The vehicle driver then
uses the cursor to follow a selected speed versus time trace. In this way, the
vehicle may be operated over a selected transient operation or driving
10.0 Test Methodology
The
laboratory vehicle testing methodology endeavours to emulate normal driving
conditions on the road while controlling those variables that have the greatest
impact on fuel consumption and exhaust emissions. One of the variables of primary concern is
the driving cycle, which accounts for rates of acceleration, vehicle speed, the
number of stops, idling time and traffic patterns. The requirement to be able
to closely replicate a driving pattern for a number of tests is very important
in evaluating the effect of a product with respect to fuel consumption and
exhaust emissions. Other variables that can have a large effect on a vehicles
fuel consumption and emissions are the ambient temperature and humidity.
11.0
Driving Cycles
During the
laboratory exhaust emission and fuel consumption tests, the vehicle is driven
on the chassis dynamometer by a driving technician according to standard
driving cycles.
The driving cycles used for the exhaust
emissions and fuel consumption testing was the Urban Dynamometer Driving Schedule
(UDDS). This is the standard duty cycles used for light duty passenger car and
truck chassis dynamometer exhaust emission and fuel consumption evaluations,
throughout North America for urban driving conditions. Generally three repeats
of each cycle, in each vehicle/product configuration are performed in order to
provide a measure of the repeatability of the tests.
Table 1
provides details of the test cycles while graphical representations of the
speed versus time data for these driving cycles have been enclosed in
appendices A.
Table 1.
Exhaust
Emission Test Cycles
12.0
Test Procedure
12.1 Program Methodology
The
evaluation test program followed a procedure of before and after chassis
dynamometer test method. The following details the program’s, steps.
- Canada Post supplied the test vehicles. The
vehicles were being pulled out of postal service and went through regular
preventive maintenance (oil change, oil and fuel filters replaced etc...)
prior to the baseline testing.
- Then
vehicles were tested in laboratory for baseline reference.
- The
fuel was replaced by standard commercial test fuel.
- The
vehicles were driven on the dynamometer over two LA-4 preparation test
cycles.
- The
vehicles were soaked for a period of 12 to 36 hours in the laboratory at a
temperature between 20 to 30 deg C.
6. After the soak period, the vehicles were pushed on a
chassis dynamometer simulating inertia weight and road load horsepower. Once installed on the dynamometer, a cold
start urban test cycle was performed at standard test temperature of 20 to 30
deg C. The measured pollutants are Carbon Monoxide, Carbon Dioxide, Oxides of
Nitrogen, total Hydrocarbons and particulate matter. Fuel consumption is also measured
using the carbon balance method.
7. The above tests step 5 and 6 was repeated on 3
consecutive days.
8. This first set of test result will serve as the
reference database (base-line), which will be used to compare the device
performance.
9. Next step is the
installation of the device by Canada Post.
10. Put the vehicle back in postal service for a 45-day
period
11. After the 45 days in service, the vehicles were
brought back to the laboratory and retested with the device, by repeating steps
3 to 9 three times.
13.0 Results
There were three
vehicles tested and identified as 01-083, 01-084, and 01-086. Table no 2
indicates the percentage difference for each vehicle and the overall average
difference of the three vehicles. Tables
no 3, 4, 5 indicates the results of each individual vehicles.
Table 2.
Percentage Difference with Device
|
Vehicle |
CO |
CO2 |
NOx |
THC |
FE |
PM |
|
01-83 |
-13.11 |
0.33 |
-1.41 |
0.00 |
0.26 |
-0.21 |
|
01-84 |
-6.50 |
-2.54 |
-7.40 |
-5.26 |
-2.55 |
1.63 |
|
01-86 |
-4.13 |
-1.86 |
-4.62 |
10.53 |
-1.89 |
-17.96 |
|
|
|
|
|
|
|
|
|
Average |
-7.92 |
-1.36 |
-4.48 |
1.75 |
-1.39 |
-5.51 |
Table 3.
Vehicle 01-083
|
UDDS Exhaust Emission Rates and Fuel Consumption |
|
|
|
|
|
|
|
|
Configuration |
Test Date |
CO |
CO2 |
NOx |
THC |
Fuel |
Particulates |
|
|
|
g/mi |
g/mi |
g/mi |
g/mi |
L/100km |
g/mi |
|
|
|
|
|
|
|
|
|
|
Baseline |
5-déc-01 |
0.84 |
531.00 |
3.28 |
|||