Confidential
AVL List GmbH (Headquarters)
Romain LARDET
FUEL CONSUMPTION SYSTEMS
GUIDELINES TO INSTALLATION & APPLICATION
Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden
Romain LARDET | ITS CONSUMPTION MEASUREMENT | 21 May 2015 | 3Confidential
MAIN GUIDELINES FOR INSTALLATION
Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden
Romain LARDET | ITS CONSUMPTION MEASUREMENT | 21 May 2015 | 4Confidential
SAFETY PRINCIPLES
735S
753C
pressure
control
modules
HC-
Detector
Testbed Standard Layout
UUT
FUEL
REFERENCE
BASEMENT
Ventilation in the testcell prevents an explosive atmosphere to exist permanently.
HC Sensors must be installed at a proper position inside the testcell.
Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden
Romain LARDET | ITS CONSUMPTION MEASUREMENT | 21 May 2015 | 5Confidential
735S
753C
pressure
control
modules
HC-
Detector
temp. influencebubbles
Testbed Standard Layout
UUT
FUEL
REFERENCE
BASEMENT
High sensor accuracy
Temperature
stability
+/- 0.02 °C
Efficient venting
Avoid bubbles, temperature and fuel storage influence
MEASURING WELL : BASIC PRINCIPLES
Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden
Romain LARDET | ITS CONSUMPTION MEASUREMENT | 21 May 2015 | 6Confidential
Sensor EngineFuel
Volume
19 l/h 20 l/h+1 l/h
Changing fuel temperature (ambient, engine impact, external heat impact, conditioning performance)
Elastic elements(Air in the fuel application, soft hoses, pressure regulators, volume buffers)
Pressure pulsations (caused by the engine)
GOAL:
Do a proper setup of the fuel circuit, especially between fuel system and engine to optimize the system performance
BASICS – MEASUREMENT CIRCUIT
Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden
Romain LARDET | ITS CONSUMPTION MEASUREMENT | 21 May 2015 | 7Confidential
FUEL SUPPLY LINE
a ….. Fuel supply from facility
b ….. Fuel System inlet
1 & 3 ….. Pump Module in case of low supply pressure
2 …... Filter unit (coarse & fine)
4 …... Shut-off Valve (controlled by the fuel system in case of overflow)
5 …… Inlet Pressure Reducer if supply pressure > 0.8 bar rel.Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden
Romain LARDET | ITS CONSUMPTION MEASUREMENT | 21 May 2015 | 8Confidential
IMPORTANCE OF PIPING DIAMETER
pump capacity inner diameter tube flow velocity
250 l/h 10 mm ~ 0.78 m/s
500 l/h 14 mm ~ 0.8 m/s
Deaeration of Fuel Lines requires
flow velocity : 0.5 m/s … 1.5 m/s
For Diesel engines you must find a compromise between flow
velocity and pressure drop in the return line in order to limit
the backpressure at the engine outlet.
For Gasoline engines, there is usually no return and it is easier
than on diesel engines. Here typical diameter are 8…12 mm
inner diameter depending on the size of the engine.
Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden
Romain LARDET | ITS CONSUMPTION MEASUREMENT | 21 May 2015 | 9Confidential
0
1
2
3
4
5
6
7
8
9
6 8 10 12 14 16 18
Flo
w S
pe
ed
[m
/s]
flow speed [m/s]vs inner diameter[mm] for several pump flow rates [l/h]
50
100
150
200
250
500
800
Internal diameter [mm]
Flow rate
[l/h]
Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden
Romain LARDET | ITS CONSUMPTION MEASUREMENT | 21 May 2015 | 10Confidential
Recommended pipe material
- Stainless steel pipes, seamless (if piping does not have to move)
- Teflon hoses (electric conductive) which are metal braided for connections
which have to be flexible (e.g. between AVL 735S and AVL 753C; between
engine bypass and fuel system)
INSTALLATION PRINCIPLES – PIPE MATERIAL
Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden
Romain LARDET | ITS CONSUMPTION MEASUREMENT | 21 May 2015 | 11Confidential
Recommended pipe material
- For engine connection lines, we recommend to use stiff conductive hoses
- Avoid any material which is „flexible“ – meaning a very
soft material which will behave like a volume buffer
element and can cause „fake“ consumption signals
INSTALLATION PRINCIPLES – PIPE MATERIAL
Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden
Romain LARDET | ITS CONSUMPTION MEASUREMENT | 21 May 2015 | 12Confidential
R > • Avoid sharp curves of tubes / pipes
underpressure can cause bubbles
bending diameter > 3* pipe diameter
• If possible avoid pipe diameter changes
• The fuel flow direction through pumps,
filters, heat exchangers etc. always has to
be from bottom to top
• Installation of „dead ends“ (drain valves,
pressure gauges) below tubes, not above
INSTALLATION PRINCIPLES – DO‘S AND DON‘TS
Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden
Romain LARDET | ITS CONSUMPTION MEASUREMENT | 21 May 2015 | 13Confidential
• Avoid sharp curves of tubes / pipes
underpressure can cause bubbles
bending diameter > 3* pipe diameter
INSTALLATION PRINCIPLES – DO‘S AND DON‘TS
Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden
Romain LARDET | ITS CONSUMPTION MEASUREMENT | 21 May 2015 | 14Confidential
• Safety measures to be considered Use a
flame filter for the device venting line if the
venting line ends in the test cell
• Each AVL Fuel Device has to be connected
to test bed grounding (PE)
INSTALLATION PRINCIPLES – DO‘S AND DON‘TS
Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden
Romain LARDET | ITS CONSUMPTION MEASUREMENT | 21 May 2015 | 15Confidential
INSTALLATION PRINCIPLES – DO‘S AND DON‘TS
- Material used for fuel piping must be electric conductive. Fuel flow through a
pipe causes electric charge separation (ions) and this can be a source of
degradation of the fuel pipes or even a spark.
- Fuel piping (and the fuel systems) must be connected to the test bed
grounding
- Quick coupling connectors have to be over AND under-pressure proof. For
applications where vacuum fuel pressure is required, this is a potential
source of air formation (air is sucked into the fuel pipe!)
Example of good fittings and
connectors suppliers
Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden
Romain LARDET | ITS CONSUMPTION MEASUREMENT | 21 May 2015 | 16Confidential
INSTALLATION PRINCIPLES – DO‘S AND DON‘TS
- The venting line of the fuel system / meter
(AVL 733S, AVL 735S, KMA4000, AVL
FuelExact) must be free and never blocked.
- There must never be residual fuel in the
venting line or in the hoses leading e.g. to
the overflow vessel.
Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden
Romain LARDET | ITS CONSUMPTION MEASUREMENT | 21 May 2015 | 17Confidential
INSTALLATION PRINCIPLES – DO‘S AND DON‘TS
- Hoses leading to a pressure sensor which is mounted above the fuel piping
(e.g. in the cable boom) MUST BE COMPLETELY FILLED WITH FUEL
Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden
Romain LARDET | ITS CONSUMPTION MEASUREMENT | 21 May 2015 | 18Confidential
INSTALLATION PRINCIPLES – DO‘S AND DON‘TS
- Hoses leading to a pressure sensor which is mounted above the fuel piping
(e.g. in the cable boom) MUST BE COMPLETELY FILLED WITH FUEL
Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden
Romain LARDET | ITS CONSUMPTION MEASUREMENT | 21 May 2015 | 19Confidential
INSTALLATION PRINCIPLES – DO‘S AND DON‘TS
- Fuel pressure measurement can also be done by directly connecting
pressure sensors to the engine bypass and using inclining hoses
Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden
Romain LARDET | ITS CONSUMPTION MEASUREMENT | 21 May 2015 | 20Confidential
AIR IN THE TEFLON TUBE TO FEM-P (PRESSURE SENSOR)
Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden
Romain LARDET | ITS CONSUMPTION MEASUREMENT | 21 May 2015 | 21Confidential
ZERO CONSUMPTION WITH AND WITHOUT AIR IN THE SYSTEM (735S/753C)
Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden
Romain LARDET | ITS CONSUMPTION MEASUREMENT | 21 May 2015 | 22Confidential
INSTALLATION PRINCIPLES – DO‘S AND DON‘TS
- Avoid any elements in the fuel application which cannot be deaerated (e.g. fuel
filter with the filter cap on top, heat exchangers wrong mounted, dead ends)
Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden
Romain LARDET | ITS CONSUMPTION MEASUREMENT | 21 May 2015 | 23Confidential
INSTALLATION PRINCIPLES – DO‘S AND DON‘TS
- Avoid any elements in the fuel application which cannot be deaerated (e.g. fuel
filter with the filter cap on top, heat exchangers wrong mounted, dead ends)
Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden
Romain LARDET | ITS CONSUMPTION MEASUREMENT | 21 May 2015 | 24Confidential
INSTALLATION PRINCIPLES – DO‘S AND DON‘TS
- Do not install components / parts which are not needed for engine testing
(because the engines requirements are met by the mere AVL Fuel System).
each additional component (like pressure regulators, auxilliary fuel
pumps) is a potential source of fuel consumption signal noise.
KEEP IT SIMPLE
Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden
Romain LARDET | ITS CONSUMPTION MEASUREMENT | 21 May 2015 | 25Confidential
INSTALLATION PRINCIPLES – DO‘S AND DON‘TS
- Keep the fuel pipes away from any heat source (e.g. other conditioning
units) or hot/cold pipes from other medias
- Keep the fuel pipes away from blowers or fans which can cool down the fuel
in the pipework
- Try to maintain a stable test cell temperature
- Fuel pressure modules have to be installed as close to the engine as
possible!
- The engine bypass has to be installed as close to the engine as possible!
- Try to avoid „fuel locks“, meaning fuel is trapped e.g. between two valves.
Due to heat impact and thermal expansion, components might be destroyed
due to overpressure. Expansion vessels can help.
Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden
Romain LARDET | ITS CONSUMPTION MEASUREMENT | 21 May 2015 | 26Confidential
THEORETICAL IMPACT OF THE TEMPERATURE STABILITY ON FUEL CONSUMPTION MEASUREMENTS
0%
2%
4%
6%
8%
10%
12%
14%
16%
18%
20%
0.01 0.1 1 10 100
Re
lati
ve E
rro
r [%
]
Actual Engine Fuel Consumption [kg/h]
Relative Errors in Fuel Consumption Measurementfor different temperature gradient in °/min
0.025°/min
0.05°/min
0.1°/min
0.3°/min
0.5°/min
Calculation based on a typical
testbed setup:
2 liters of diesel fuel between
the sensor and the injectors
Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden
Romain LARDET | ITS CONSUMPTION MEASUREMENT | 21 May 2015 | 27Confidential
Engine inlet temperature measurement
(T_FUEL_I)
CHECK OF THE ENGINE FUEL FEED TEMPERATURE DURING A WHTC CYCLE
Controlled fuel temperature
At the beginning and at the end of the test run,
the fuel temperature at the engine inlet differs
from set temperature of the fuel system.
If there is no fuel flow to the injection system,
the temperature of the fuel in the engine line will
be influenced by ambient temperature
Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden
Romain LARDET | ITS CONSUMPTION MEASUREMENT | 21 May 2015 | 28Confidential
CHECK OF THE ENGINE FUEL FEED TEMPERATURE
DURING A WHTC
The measurement uncertainty in transient cycles is very influenced by the
temperature stability of the fuel over time. With an AVL FuelExact, we achieve on
this demanding WHTC a temperature stability of about +/-0.1°C around 34.6°C.
This value is not a specification but the result of a good installation combined with
the heating/cooling capabilities and temperature regulation strategy of the system.
Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden
Romain LARDET | ITS CONSUMPTION MEASUREMENT | 21 May 2015 | 29Confidential
INSTALLATION PRINCIPLES – PIPE THERMAL INSULATION
Why the need for pipe insulation?
- The fuel temperature is usually conditioned at the device outlet and
well controlled. To minimize any heat transfer (impact from outside and
/ or heat loss to ambient), it is strongly recommended to insulate the
fuel piping between the fuel system up to the engine bypass
- Optimization of the measurement accuracy by minimizing the influence
of non stable environmental conditions
- Fuel temperature at the engine inlet will be approximately the same
like at the fuel system outlet (no need to change the set temperature
for the fuel conditioning system)
Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden
Romain LARDET | ITS CONSUMPTION MEASUREMENT | 21 May 2015 | 30Confidential
Results
(1) without insulation: CT 74,0
(2) with insulation 10 mm:CT 26,0
(3) with insulation 20 mm:CT 22,0
Calculated for a tube
length 5m
NW 10mm (inner diameter)
Flow rate 250l/h
Fuel Diesel
Fuel Temperature 50°C
Air Temperature 20°C
Temperature loss of a fuel pipe with and without thermal insulation
10 mm insulating material already
shows improvement on thermal stability
INSTALLATION PRINCIPLES – PIPE THERMAL INSULATION
Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden
Romain LARDET | ITS CONSUMPTION MEASUREMENT | 21 May 2015 | 31Confidential
INSTALLATION PRINCIPLES – PIPE THERMAL INSULATION
Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden
Romain LARDET | ITS CONSUMPTION MEASUREMENT | 21 May 2015 | 32Confidential
Conditions:
- engine stand still
- conditioning of 753C
- no venting
- 733S + 753C
Influence of changing ambient air temperature
INSTALLATION PRINCIPLES – PIPE THERMAL INSULATION
Temperature
of fuel return [°C]
Temperature at
753C outlet [°C]
Temperature of
ambient air
[°C]
Consumption variation [kg/h]
(FB_VAL)
Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden
Romain LARDET | ITS CONSUMPTION MEASUREMENT | 21 May 2015 | 33Confidential
SUMMARY
Optimize fuel piping between Fuel System
Piping material & fittings material
Piping length
Piping diameter (=> flow speed & pressure drop)
Piping insulation
Bypass close to engine
Do not trap air between fuel system and engine
Keep it simple and limit the fuel volumes
Manage safety :
Ventilation
HC Sensors
Overflow / venting line
Any unauthorized copying, disclosure or distribution of the presentation is strictly forbidden