automotive systems course (module 04) - fuel systems in compression ignition (ci) internal...
TRANSCRIPT
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Fuel systems – CI engines
Mário Alves ([email protected])
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Outline
• Objective of fuel systems
• Classification of fuel systems
• Evolution – powertrains, technology, fuel pressure, regulations
• Objectives and requirements of Diesel fuel injection systems
• Evolution of Diesel fuel injection systems
• Diesel fuel injection system – architecture/components
• In-line pump systems
• Distributor-type pump injection systems
• Unit-Injector injection systems
• Unit-Pump injection systems
• Common-rail systems
• Fuel Injectors
• Exhaust system
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Objective of fuel injection systems
• To deliver fuel into the cylinders
• at proper timings (optimizing power, preventing pre-ignition)
• in accurate amounts (for optimal A/F ratio, function of load, RPM,
engine temperature,…)
• in the right form (fuel atomization, for full combustion and lower
emissions)
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Classification of fuel systems (CI and SI)
Operating principle
ICE type single or multiple injectors
direct/indirect injection
technology
Mechanical SI (single point) indirect Carburetor
Diesel (multi-point) direct or indirect
Injection Pump (in-line or rotary), few hundred bars
Electronic SI SPI indirect in the throttle body, few bars
MPI indirect Fuel rail, few bars
direct Fuel rail, tens of bars
Diesel (multi-point) direct Fuel-rail or pump/unit-injection, hundreds to thousands of bars
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Evolution – market share (Europe and USA)
http://www.turnermason.com/index.php/oh-lord-wont-you-buy-me-
a-mercedes-benz-or-audi-vw-or-bmw-as-long-as-its-diesel/
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Evolution – light vehicles powertrain (current)
http://www.autocar.co.uk/car-news/industry/uk-under-pressure-european-air-quality-ruling
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Evolution – light vehicles powertrain (forecast)
http://www.economist.com/news/special-report/21576219-carmakers-are-
hedging-their-bets-powering-cars-great-powertrain-race
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Evolution – European emission standards (Diesel)
http://www.clm.co.uk/diesel-emissions-crackdown/
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Evolution – European emission standards
https://www.ngk.de/en/technology-in-detail/lambda-sensors/basic-
exhaust-principles/euro-standards/
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Evolution – emission reduction vs. technologies
http://www.accessmagazine.org/articles/fall-2001/clean-diesel-overcoming-noxious-fumes/
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Evolution – emission reduction vs. technologies
http://www.transportpolicy.net/index.php?title=EU:_Light-duty:_Emissions
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Evolution – emission reduction vs. technologies
https://www.researchgate.net/publication/260643808_Particulate_emissions_from_diesel_en
gines_Correlation_between_engine_technology_and_emissions/figures
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Evolution – fuel pressure vs. models
• 1927: 100 bar • 1st series-production inline injection pump; MAN truck
• 1975: 300 bar • 1st VE distributor injection pump (VW Golf D)
• 1989: 900 bar • Axial-piston pump (Audi 100 TDI)
• 1995:
• 1st Diesel common-rail system for trucks (by Denso)
• 1997: 1,350 bar • 1st common rail system for light-duty (Bosch/fiat, Alfa-Romeo 156 2.4 JTD)
• 1998: 1,500 – 1,750 bar • VP 44 radial-piston pump (Opel Vectra, Audi A6 2.5 TDI, 1996; BMW 320d)
• 1998: 2,050 bar • 1st unit injector system (VW Passat TDI, 1998)
• 2003: > 2,000 bar • Bosch common rail with piezo injector (first deployed in the Audi A6 3.0 TDI, 2003/4)
• 2013/14: 2,500 bar • Denso releases 1st common-rail system with 2500 bar (2013)
• Bosch releases CRS3-25 common-rail system with 2500 bar (2014)
http://www.globaldenso.com/en/newsreleases/130626-01.html
http://www.car-engineer.com/injection-pressure-evolution-diesel-engine/
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Evolution – supercharging/injection pressures
https://www.researchgate.net/publication/260643808_Particulate_emissions_from_diesel_e
ngines_Correlation_between_engine_technology_and_emissions/figures
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Evolution – production of different Diesel technologies
http://pt.slideshare.net/Henriquecarvalhob/tendncias-dos-sistemas-diesel
• Light vehicles (by Bosch)
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Evolution – production of different Diesel technologies
http://pt.slideshare.net/Henriquecarvalhob/tendncias-dos-sistemas-diesel
• Commercial and heavy-duty vehicles (by Bosch)
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Classification of CI fuel systems
• Class. according to when/how high fuel-pressure is produced
• High pressure generated when injection occurs (dependent on RPM)
• In-line pump systems (PE by Bosch)
• Distributor-pump systems (VE by Bosch)
• axial-piston
• radial piston
• Unit-Injector Systems (UIS by Bosch)
• Unit-Pump Systems (UPS by Bosch)
• High pressure always available
(independent of RPM)
• Accumulator-type = Common-Rail
Systems (CRS by Bosch)
http://www.appropedia.org/Engine_components
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Classification of CI fuel systems
Distributor
pump
Common-
rail
Unit-
Injector
Unit-
pump
http://clwydinjectionservices.boschauto.co.uk/bosch-diesel/
http://www.trucktrend.com/how-to/expert-advice/0904dp-diesel-injection-pumps/
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Classification of CI fuel systems
• CI fuel systems can be classified according to where the fuel
is injected
• Indirect injection (right)
• Direct injection (left)
http://www.turnermason.com/index.php/oh-lord-wont-you-buy-me-a-mercedes-benz-
or-audi-vw-or-bmw-as-long-as-its-diesel/
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Classification of CI fuel systems
https://www.quora.com/What-is-the-difference-between-direct-and-
indirect-fuel-injection
Direct Injection
Indirect Injection
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Requirements of CI injection systems
• Generic objectives of a fuel injection system
• Reduce emissions and fuel consumption
• Maximize engine power/performance
• Requirements
• atomize & pulverize fuel very finely (better combustion)
• high pressure differential (btw fuel and combustion chamber)
• pressure inside cylinder 100 bar
• high fuel pressure (> 300 bar)
• optimal-spray injectors
• optimize injection timings and quantity (mass)
• ECU-control (real-time, closed-loop)
• fast-response injectors (piezo-electric)
• minimize pollutant emissions (according to regulations)
• EGR, catalyst, SCR, particulate filters
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Diesel fuel injection system – architecture/components
• Major component groups
• Low (fuel) pressure system
• deliver fuel from the tank to the fuel injection system
• fuel tank, fuel supply pump, fuel filter.
• High (fuel) pressure system
• create high pressure, measure, control and deliver the fuel to the
combustion chamber
• high pressure pump, fuel injector; common-rail systems also include
a high-pressure fuel accumulator (aka fuel rail)
• Control system
• sensors, ECU, actuators
• in purely mechanical systems, control is performed by the high
pressure pump
http://www.dummies.com/how-to/content/how-do-diesel-engines-work.html
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Diesel fuel injection system – architecture/components
• Overall architecture and main components
http://www.denso.com.sg/products/pump/diesel-fuel-injection
Injection-pump type Common-rail type
http://www.dummies.com/how-to/content/how-do-diesel-engines-work.html
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Diesel fuel injection system – low pressure circuit
• Main objective • store fuel and feed the high-pressure circuit
• Main components • Fuel tank
• store and cool the fuel
• Feed pump (aka fuel supply, low-pressure, transfer, lift or primary pump)
• not used in some fuel systems (high-pressure pump does the job)
• drag fuel from the tank and push it to the high-pressure pump
• usually includes a pre-filter
• Fuel filter
• filters impurities and purges water out of the fuel circuit
• prevents engine damage & improves its performance
• Fuel heater
• avoid the forming of paraffin wax, in case of low temperatures (which can stop the fuel flow)
• can be embedded into the fuel filter
• Charcoal (carbon) canister
• transforms evaporated fuel into liquid fuel
• Pipes
• fuel feed/return
https://www.dieselnet.com/tech/diesel_fi_common-rail_control.php
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Diesel fuel injection system – low pressure circuit
• Fuel tank main objectives
• store the fuel
• receive the fuel return (backflow) from the high-pressure components
• host other components, e.g. feed pump and fuel level gauge
• Must feature
• optimal volume, shape and location
• robustness to prevent spillage and leakage, even in case of an accident,
e.g. rollover; must also be fire-proof
• fuel overheating and overpressure detection and mitigation, via
ventilation and safety valves
• fuel level gauge
• electrical harness for feed pump (if located inside the tank)
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Diesel fuel injection system – low pressure circuit
• Tank + canister example (Mercedes SLK320)
http://www.benzworld.org/forums/r170-slk-class/1434072-fuel-tank-filling-problem-slk320-pump.html
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Diesel fuel injection system – low pressure circuit
http://www.tb-training.co.uk/CIsys.htm
http://www.autorepairnewark.info/how-can-mechanical-and-electric-fuel-pumps-work.html
• Feed pump (mechanically-driven)
• driven by camshaft, outside the tank
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Diesel fuel injection system – low pressure circuit
• Feed pump (electrically-driven)
• ECU-controlled, inside the tank
• produces a few bars
https://www.dieselnet.com/tech/diesel_fi_common-rail_control.php
http://www.agcoauto.com/content/news/p2_articleid/195
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Diesel fuel injection system – low pressure circuit
• Fuel filters remove
• m particles
• water (manual
or automatic
draining)
• Water sensor
• signals full
water chamber
http://de.bosch-automotive.com/en/parts_and_accessories/service_parts_1/filters_1/diesel_filters_1/diesel_filters_1
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Diesel fuel injection system – low pressure circuit
• Fuel heater
• avoids wax forming
for low temperatures
• upstream the filter
• inside/outside filter casing
http://www.justanswer.com/dodge/253gc-sometimes-truck-does-not-start-right-away-just-cranks.html
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Diesel fuel injection system – in-line pump systems
• One pump element for each engine cylinder
• elements arranged in a row
• activated by a camshaft in the in-line pump
• driven by the combustion engine
• via control wheels or chains
• Each pump element is connected via a high-pressure
line to an injection nozzle installed in the cylinder
head by means of a nozzle holder
• nowadays, the amount of fuel
injected and the start of delivery
are controlled by ECU.
• In-line fuel-injection pumps achieve
injection pressures of up to 1,300 bar
http://what-when-how.com/automobile/in-line-injection-pumps-automobile/
http://products.bosch-mobility-solutions.com/en/de/_technik/component/PT_CV_DS_Other-Injection-Systems_PT_CV_Diesel_2112.html
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Diesel fuel injection system – in-line pump systems
• Amount of injected fuel depends on
• factory settings, manual adjustments, RPM, coolant temperature,
barometric pressure, accelerator position, start & stop solenoids
http://www.sl113.org/forums/index.php?topic=790.0
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Diesel fuel injection system – in-line pump systems
http://www.sl113.org/forums/index.php?topic=886.0
http://www.free-ed.net/sweethaven/MechTech/Automotive01/AutomotiveSystems03_Files.asp?iNum=42
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Diesel fuel injection system – distributor-pump systems
• Distributor pumps classification
• axial piston or radial piston
• purely mechanically-controlled or ECU-controlled
http://de.bosch-
automotive.com/en/parts_and_accessories/motor_and_sytems/diesel/conventional_injection/conventional_injection_diesel_motorsys_parts
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Diesel fuel injection system – distributor-pump systems
• Axial-piston pump basics
• pistons attached to a cylindrical block which move in the same
direction as the block's centerline (axially)
• reliable operation and simple design
http://www.globalspec.com/learnmore/flow_transfer_control/pumps/piston_plunger_pumps
http://vwdiesel.net/forum/index.php/topic,30340.0.html
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Diesel fuel injection system – distributor-pump systems
• Radial-piston pump basics
• pistons arranged like wheel spokes around a cylindrical block.
• drive shaft rotates this cylindrical block which pushes or slings
the pistons, causing compression and expansion
• eccentricity between the piston housing and cylinder block
centerlines determines the piston stroke
• low noise level and high efficiency
http://www.globalspec.com/npapics/93/159940_050120134659_ExhibitPic.jpg
http://i1104.photobucket.com/albums/h331/specsalot/DelphiDFP6injectoronVW12lTDI-H.jpg http://www.globalspec.com/learnmore/flow_transfer_
control/pumps/piston_plunger_pumps
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Diesel fuel injection system – distributor-pump systems
• Mechanically-controlled (governed) axial-piston
distributor fuel-injection pump (VE by Bosch)
• typically up to 1100 bar; up to 1200 bar (SOTA VE-EDC)
http://www.dieselmotors.info/fuel-systems/diesel-engine-bosch-ve-fuel-pump.html
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Diesel fuel injection system – distributor-pump systems
• VE pump
http://www.dieselmotors.info/fuel-systems/diesel-engine-bosch-ve-fuel-pump.html
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Diesel fuel injection system – distributor-pump systems
http://www.tb-training.co.uk/CIsys.htm
• VE pump
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Diesel fuel injection system – distributor-pump systems
• Feed pump (aka vane pump)
• draws fuel through the filter from
the tank and supplies it to the
distributor plunger
• as the rotor spins, centrifugal force
holds the vanes against the walls of
the pressure chamber
• off-center (eccentric layout) of the
rotor and pressure chamber
"squeezes" fuel trapped between the
vanes and forces it out the delivery
port
• delivery pressure 3-7 bar,
depending on RPM
http://www.zexel.hk/news_more.asp?NewsID=97
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Diesel fuel injection system – distributor-pump systems
• High-pressure compression and distribution
• injection pump driveshaft turns vane pump, distributor plunger,
and cam plate (as a unit)
• springs hold the cam plate and distributor plunger against
stationary rollers the plunger moves back and forth as it turns
http://chris.chemidl.in/vw-diesel-info/diesel-basics/injection-pump-distribution-injection-metering/
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Diesel fuel injection system – distributor-pump systems
• High-pressure compression and distribution
• whenever an intake port on the plunger is in line with the filling
port in the pump body, fuel from the vane pump fills the high
pressure chamber.
http://chris.chemidl.in/vw-diesel-info/diesel-basics/injection-pump-distribution-injection-metering/
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Diesel fuel injection system – distributor-pump systems
• High-pressure compression and distribution
• as the plunger continues to turn, the outlet port lines up with the
injection ports in the pump body
• the cam plate pushes the plunger to “squeeze” the fuel in the high
pressure chamber
http://chris.chemidl.in/vw-diesel-info/diesel-basics/injection-pump-distribution-injection-metering/
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Diesel fuel injection system – distributor-pump systems
• High-pressure compression and distribution
• the delivery valve opens under pressure and high pressure fuel is
supplied to the injector
• The ports in the pump are arranged so that the injectors receive
fuel in the cylinder firing sequence
http://chris.chemidl.in/vw-diesel-info/diesel-basics/injection-pump-distribution-injection-metering/
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Diesel fuel injection system – distributor-pump systems
• High-pressure compression and distribution
• Complete sequence
• A – suction
• B – delivery
http://www.dieselmotors.info/fuel-systems/diesel-engine-bosch-ve-fuel-pump.html
http://what-when-how.com/automobile/bosch-ve-type-distributor-pump-automobile/
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Diesel fuel injection system – distributor-pump systems
• Governing the fuel injection quantity
• amount of fuel injected is controlled by a governor
• injection cut-off point depends on RPM & engine load
• controlled by the metering sleeve on the distributor plunger
• metering sleeve covers and uncovers a relief port in the
plunger – uncovering the relief port stops injection
http://www.zexel.hk/news_more.asp?NewsID=97
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Diesel fuel injection system – distributor-pump systems
• Governing the fuel injection quantity – engine start
• when engine is not running, starting spring presses the starting
lever to the left so that the metering sleeve moves to the right.
• distributor plunger must move further to expose the relief port
• injection lasts longer so that more fuel is supplied during starting
http://chris.chemidl.in/vw-diesel-info/diesel-basics/injection-pump-distribution-injection-metering/
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Diesel fuel injection system – distributor-pump systems
• Governing the fuel injection quantity – idle speed
• flyweights partially expanded governor sleeve moves right
• starting lever pushes control lever metering sleeve moves left
• distributor plunger now moves less to expose the relief port.
• injection lasts shorter so that less fuel is supplied at idle
http://chris.chemidl.in/vw-diesel-info/diesel-basics/injection-pump-distribution-injection-metering/
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Diesel fuel injection system – distributor-pump systems
• Governing the fuel injection quantity – acceleration
• control lever is pulled to the left by the accelerator lever
• metering sleeve is moved to the right (fuel is injected before relief
port is uncovered)
• RPM increases until governor movement “neutralizes” effect of
pedal linkage
http://chris.chemidl.in/vw-diesel-info/diesel-basics/injection-pump-distribution-injection-metering/
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Diesel fuel injection system – distributor-pump systems
• Governing the fuel injection quantity – max RPM
• accelerator lever at “full load” maximum RPM
• flyweights stretch governor spring control lever moves right
• metering sleeve moves left (uncovers relief port at the beginning
of the distribution plunger stroke)
• LESS fuel injected and top speed is limited.
http://chris.chemidl.in/vw-diesel-info/diesel-basics/injection-pump-distribution-injection-metering/
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Diesel fuel injection system – distributor-pump systems
• Governing the fuel injection quantity – 4 states
http://www.zexel.hk/news_more.asp?NewsID=97
STARTING IDLE ACCELERATION MAX RPM
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Diesel fuel injection system – distributor-pump systems
• Governing the fuel injection timing (advance)
• as RPM increases, stroke timing becomes shorter and injection
timing becomes longer
• burning must begin sooner to ensure that peak combustion
pressures still occur at the most efficient point after TDC
• injection timing is advanced by hydraulic piston in injection pump
http://www.zexel.hk/news_more.asp?NewsID=97
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Diesel fuel injection system – distributor-pump systems
• Governing the fuel injection timing (advance)
• > RPM fuel pressure from the vane pump
• vane pump pressure pushes the injection advance piston to the left
against the spring so that the roller housing turns slightly
• distributor plunger beings injection sooner
http://www.zexel.hk/news_more.asp?NewsID=97
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Diesel fuel injection system – distributor-pump systems
• Governing the fuel injection timing/quantity
http://www.zexel.hk/news_more.asp?NewsID=97
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Diesel fuel injection system – distributor-pump systems
• Bosch VP44 radial-piston injection pump
• introduced in 1998 to meet emissions standards (before common rail fuel
systems were available, in the 2000s) and to reduce fuel consumption
• direct-injection system for small to medium-size engines
• 2 ECUs control fuel injection quantity/timing
• injection pressures up to 1600 bar
http://zisokilt.jimdo.com/2012/06/29/bosch-vp44-diagram/
http://www.trucktrend.com/how-to/expert-advice/1303dp-injection-system-basics/
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Diesel fuel injection system – distributor-pump systems
• Bosch VP44 radial-piston injection pump
• Engine Control Unit – ECU (aka ECM)
• receives and processes data from sensors
• commands FPCM (via CAN) for target fueling and timing
• Fuel Pump Control Module – FPCM
• embedded in the injection pump
• contains fueling, timing and diagnostic data.
• responds to ECM commands according to fueling data and timing in
its memory and actuates fueling+timing solenoids
http://dodgeram.org/tech/dsl/ISB/Vp44.htm
http://www.justanswer.com/heavy-equipment/4q11a-5-9-code-254-fuel-shut.html
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Diesel fuel injection system – distributor-pump systems
• Bosch VP44 radial-piston injection pump
• section of the circuit diagram & sensors
http://www.justanswer.com/heavy-equipment/7fyc6-2003-freightliner-mt55-rolling-chassis-cummins-5-9.html
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Diesel fuel injection system – distributor-pump systems
• Bosch VP44 radial-piston injection pump
• fuel injection flow and fuel injection timing (advance) control
http://www.aficionadosalamecanica.net/gestion_electronica_diesel2.htm
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Diesel fuel injection system – unit-injector systems
• Unit Injector (UIS) and Unit Pump (UPS) systems
• each cylinder is served by a separate injection pumping element
or injection pump in close proximity to the cylinder
• Unit Pump (UP) systems
• enable short high pressure fuel lines (pump close to injector)
• Unit injector (UI) systems combine the pumping element
and the injector into one assembly
• eliminates high pressure lines
• < line dynamics problems (e.g. delay)
• > injection pressures (up to 2500 bar)
http://www.trucktrend.com/how-to/expert-advice/0904dp-diesel-injection-pumps/
https://www.dieselnet.com/tech/diesel_fi_ui.php
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Diesel fuel injection system – unit-injector systems
• Unit Injector Systems (UIS)
1. pressure generation unit
2. camshaft
3. rocker arm (roller type)
4. electromagnetic valve
5. injection nozzle
http://www.chiptuning.co.za/howdieselworks.php
http://www.northerndiesel.co.za/INJECTORS.htm
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Diesel fuel injection system – unit-injector systems
• UIS camshaft and basic control diagram
• engine camshaft has 3 cams (lobes) per cylinder
• ECU controls fuel injection quantity/timing
http://www.dongamarine.com/subtececu.html
http://www.gwdale.co.uk/UnitInjector.html
Admission & Exhaust cams
Unit injector cam
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Diesel fuel injection system – unit-injector systems
• Unit injector components
1. Electromagnetic (solenoid) valve
2. Pump tappet
3. Pump piston (plunger)
4. High pressure chamber (barrel)
5. Nozzle assembly
• spring
• nozzle check
• nozzle tip
http://engine-assembly-disassembly.blogspot.pt/2014/11/systems-operation-
c-15-c-16-and-c-18_85.html
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Diesel fuel injection system – unit-injector systems
• Fuel injection cycle
1. Filling
• admission of fuel into the (high-pressure) fuel chamber
2. Pre-injection
• preparation for the injection phase
3. Injection
• high-pressure fuel injection into the combustion chamber
4. End of injection
http://engine-assembly-disassembly.blogspot.pt/2014/11/systems-operation-
c-15-c-16-and-c-18_85.html
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Diesel fuel injection system – unit-injector systems
• Filling phase
1. rocker arm releases tappet (tappet spring
pushes it upwards)
2. plunger is pulled up by the tappet and the
tappet spring
3. upward movement of the plunger causes the
pressure in the plunger cavity to drop below
fuel supply pressure
4. Fuel flows from the fuel supply passage (via
open poppet valve) into the plunger cavity,
until as the plunger travels upward
5. when plunger reaches top of stroke, plunger
cavity is full of fuel and fuel flow stops
• this is the beginning of pre-injection
http://engine-assembly-disassembly.blogspot.pt/2014/11/systems-operation-
c-15-c-16-and-c-18_85.html
Mechanical movement
Moving parts
Fuel movement
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Diesel fuel injection system – unit-injector systems
• Pre-injection phase
1. pre-injection starts with
• injector tappet/plunger at the top of the
fuel injection stroke
• plunger cavity full of fuel
• poppet valve opened
• nozzle closed
2. rocker arm starts pushing tappet/plunger
downwards
3. fuel leaves the plunger cavity, flowing through
the open poppet valve to the fuel supply
passage in the cylinder head
• pre-injection continues until solenoid is
energized, closing the poppet valve and
triggering injection (next)
http://engine-assembly-disassembly.blogspot.pt/2014/11/systems-operation-
c-15-c-16-and-c-18_85.html
Fuel supply pressure
Injection pressure
Moving parts
Mechanical movement
Fuel movement
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Diesel fuel injection system – unit-injector systems
• Injection phase
(rocker arm keeps pushing tappet/plunger down)
1. ECU sends a current to the electromagnetic
valve solenoid, attracting the armature
2. poppet valve closes, blocking flow path for the
fuel that was leaving the high pressure chamber
(fuel return line to the tank)
3. plunger continues its downward movement,
compressing fuel in the high-pressure chamber
4. when fuel pressure reaches threshold, high
pressure fuel force overcomes spring force
5. high-pressure fuel flows out of the injector
nozzle (start of injection)
• injection continues while plunger moves
downwards and energized solenoid holds the
poppet valve closed
http://engine-assembly-disassembly.blogspot.pt/2014/11/systems-operation-
c-15-c-16-and-c-18_85.html
Fuel supply pressure
Injection pressure
Moving parts
Mechanical movement
Fuel movement
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Diesel fuel injection system – unit-injector systems
• End of injection phase
1. ECU stops current flow to the solenoid,
releasing the armature
2. poppet valve opens, unblocking flow path for
the fuel to leave the high pressure chamber
3. this results in a rapid drop in injection pressure
4. when injection pressure drops below a certain
threshold, the force of the nozzle spring
overcomes the force of the fuel pressure
5. injection nozzle closes and fuel injection stops
http://engine-assembly-disassembly.blogspot.pt/2014/11/systems-operation-
c-15-c-16-and-c-18_85.html
Fuel supply pressure
Moving parts
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Diesel fuel injection system – unit-injector systems
• UIS diagram (detailed) 1. Accelerator position (APP) sensor
2. Battery
3. Crankshaft position (CKP) sensor
4. Engine control module (ECM) 5. Engine control relay
6. Engine coolant temperature (ECT) sensor
7. Exhaust gas recirculation (EGR) solenoid
8. Fuel cooler
9. Fuel filter
10. Unit injector
11. Fuel lift pump 12. Fuel lift pump relay
13. Fuel pressure regulator
14. Fuel tank
15. Fuel temperature sensor
16. Glow plug relay
17. Glow plug
18. Glow plug warning lamp
19. Ignition switch
20. Intake air temperature (IAT) sensor
21. Malfunction indicator lamp (MIL)
22. Manifold absolute pressure (MAP) sensor
23. Mass air flow (MAF) sensor
24. Turbocharger wastegate regulating valve
25. Vehicle speed sensor (VSS)
http://www.chiptuning.co.za/howdieselworks.php
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Diesel fuel injection system – unit-pump injection systems
• One pump per cylinder (unit-pump), directly driven by engine camshaft
• Unit-pump connected to injector via short high-pressure line.
• For medium to heavy-duty diesel engines (up to 80 kW per cylinder)
• Fuel-injection pressures of up to 2,200 bar
• Injection quantity/timing
• Purely Mechanically-controlled
• ECU-controlled
http://www.hydrotransonline.com/Products/images/Diesel_UPS.jpg
http://www.indiamart.com/stanadyne-amalgamations/products.html
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Diesel fuel injection system – unit-pump injection systems
• System schematics (ECU-controlled system)
http://link.springer.com/article/10.1007%2F978-3-8348-9715-2_11/lookinside/000.png
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Diesel fuel injection system – unit-pump injection systems
• Unit-pump and fuel
injector detail
http://link.springer.com/article/10.1007%2F978-3-8348-9715-2_11/lookinside/000.png
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Diesel fuel injection system – common-rail systems
• High-pressure fuel accumulator feeds all
injectors
• usually known as common-rail
• High pressure fuel pump feeds fuel rail
• pressure is independent of RPM
• ECU controls fuel pressure and injection
quantity/timing
• First series-production systems
• Denso, 1995, heavy-duty trucks
• Hino Rising Ranger
• Bosch/Fiat, 1997, passenger cars
• Alfa Romeo 156 2.4 JTD
• Mercedes-Benz C 220 CDI
http://www.partinfo.co.uk/articles/106
https://www.dieselnet.com/tech/diesel_fi_common-rail.php
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Diesel fuel injection system – common-rail systems
• Main components (high-pressure circuit)
1. Damping case, fuel return
2. High pressure accumulator
3. Fuel Pressure sensor
4. High pressure line
(accumulator to injector)
5. Fuel return line
6. Injector
7. High-pressure pump
8. Pressure regulator (pump)
9. High pressure line (to rail)
10. Pressure regulator (rail)
http://workshop-manuals.com/vauxhall/astra-
h/j__engine_and_engine_aggregates/fuel_injection_systems/electronic_diesel_control_edc_16_c39/
component_locator/illustration_of_common_rail/
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Diesel fuel injection system – common-rail systems
• System diagram
1. Feed pump
(not in all systems)
2. Filter
3. Overflow valve
4. Fuel return manifold
5. High Pressure pump
6. Pressure control valve
(not in all systems)
7. Rail pressure sensor
8. Fuel rail
9. Injectors
10. ECU
11. Fuel temperature sensor
12. Other sensors
http://www.partinfo.co.uk/articles/127
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Diesel fuel injection system – common-rail systems
• Example of control diagram
http://pt.slideshare.net/KamalVora1/dr-vora-ppt-chapter-6-crs
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Diesel fuel injection system – common-rail systems
• Main manufacturers
• Denso
• HP2, HP3, HP4
• Bosch
• CRS1/CP1, CRS2/CP2, CRS3/CP3, CRS4/CP4
• Delphi
• Multec/DFP6
• Other
• Caterpillar
• Siemens
http://inyecciondieselnaval.blogspot.pt/2012/01/bosch-y-los-
sistemas-common-rail.html
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Diesel fuel injection system – common-rail systems
• Bosch CRS1/CP1
http://www.remmington.info/Common%20rai
l%20pumps.htm
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Diesel fuel injection system – common-rail systems
• Bosch CRS3/CP3 EDC16 – fuel circuits
http://www.slideshare.net/amgadradhihadi/common-rail-diesel-fuel-systems
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Diesel fuel injection system – common-rail systems
• Bosch CRS3/CP3 EDC16 – components overview
http://www.slideshare.net/amgadradhihadi/common-rail-diesel-fuel-systems
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Diesel fuel injection system – common-rail systems
• Bosch CRS3/CP3 EDC16 – electromechanical diagram
http://pt.slideshare.net/KamalVora1/dr-vora-ppt-chapter-6-crs
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Diesel fuel injection system – common-rail systems
• Bosch CRS3/CP3 EDC16 – ECU input/output diagram
http://pt.slideshare.net/KamalVora1/dr-vora-ppt-chapter-6-crs
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Diesel fuel injection system – common-rail systems
• Bosch CP3 – main components (V8)
• high-pressure pump, fuel rails, injectors and fuel lines
http://www.trucktrend.com/how-to/parts-accessories/1204dp-inside-the-
bosch-cp3-injection-pump/
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Diesel fuel injection system – common-rail systems
• Bosch CP3 – low-pressure circuit
A. Feed pump
B. Flow rate limiter throttle
C. overflow valve
D. Fuel metering unit (fuel pressure regulator)
E. zero delivery throttle
http://www.trucktrend.com/how-to/parts-
accessories/1204dp-inside-the-bosch-cp3-injection-
pump/
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Diesel fuel injection system – common-rail systems
• Bosch CP3 – high-pressure circuit
A. Suction valves
B. Plungers (B)
C. High-pressure valves
http://www.trucktrend.com/how-to/parts-
accessories/1204dp-inside-the-bosch-cp3-injection-pump/
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Diesel fuel injection system – common-rail systems
• Bosch CP3 – high-pressure pump overview
http://img.photobucket.com/albums/v374/grand_toots/2000%20Eddie%20Bauer%20Ford%20Explorer/HPFP.jpg
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Diesel fuel injection system – common-rail systems
• Bosch CP3 – high-pressure pump front/side views
http://www.slideshare.net/amgadradhihadi/common-rail-diesel-fuel-systems
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Diesel fuel injection system – common-rail systems
• Bosch CP3 – high-pressure pump component list
1. Flange
2. Shaft
3. Polygonal ring
4. Housing
5. Gear pump
6. Overflow valve
7. Low-pressure inlet
8. Fuel metering unit
9. Backflow connector
10. High-pressure connector
11. Plunger
12. Bucket
13. Suction valve
14. High-pressure valve (out to rail)
http://www.trucktrend.com/how-to/parts-accessories/1204dp-inside-the-bosch-cp3-injection-pump/
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Diesel fuel injection system – common-rail systems
• Unit-Pump common rail systems (by Delphi)
• Low-cost, small engines (India market)
http://www.automotiveworld.com/megatrends-articles/global-tier-one-found-something-common-rail-indias-largest-supplier/
http://www.delphi.com/manufacturers/other/powertrain/dsl_upcr
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Fuel injectors
• Fuel injectors are important to
• improve engine performance/power
• reduce fuel consumption
• mitigate exhaust gas emissions
• Injector malfunctioning leads to:
• high exhaust emissions
(particularly unburnt hydrocarbons)
• increased fuel consumption
• erratic idling
• poor cold starting
• engine knocking
• engine hesitation
• reduced engine horsepower
http://www.autozone.com/repairinfo/repairguide/repairGuideContent.jsp?pageId=0900c1528026672a
http://padstow.carmechanic.net.au/diesel-injector-cleaning/2802
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Fuel injectors
• Injectors can be classified according to:
• Type of ICE and fuel
• SI or CI
• Function (what are aimed at)
• single-point (indirect) injection, multi-point indirect
injection, direct injection, cold-start injection
• Working principle
• (purelly) mechanical, electromagnetic, piezoelectric
• Nozzle type
• Single/multiple hole nozzle, pintle nozzle, pintaux nozzle
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Fuel injectors
• Nozzle types
http://www.splashmaritime.com.au/Marops/data/text/Med3tex/Engpropmed2_files/image054.jpg
http://europe.autonews.com/apps/pbcsi.dll/storyimage/CA/20061113/ANE/61109031/AR/0/AR-61109031.jpg&MaxW=622&cci_ts=20061109144328
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• Injector working principle
Fuel injectors
http://vegburner.co.uk/dieselengine.html
http://image.dieselpowermag.com/f/tech/general/9382293%20w799%20h499%20cr1%20ar0/0703dp_14_z+bosch_diesel_injection_system+latest_piezo_injectors.jpg
Mechanical
Electromagnetic
Piezoelectric
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Fuel injectors
• Injection has greatly evolved
• more fuel pressure
• multiple jets
• Leads to
• better fuel atomization
• less engine noise
• less exhaust emissions
http://www.techlineinfo.com/fiat-multijet-ii-the-next-generation-
green-diesel-engine-technology/
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Exhaust system
• …
• …
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Glossary (English/Portuguese)
• …
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Recommended references
• https://www.dieselnet.com/
• http://www.appropedia.org/Engine_components
• http://www.trucktrend.com/how-to/expert-advice/0904dp-diesel-injection-pumps/
• http://auto.howstuffworks.com/diesel.htm
• http://www.tb-training.co.uk/CIsys.htm
• http://www.slideshare.net/amgadradhihadi/common-rail-diesel-fuel-systems
• http://pt.slideshare.net/KamalVora1/dr-vora-ppt-chapter-6-crs
• http://www.walshcarlines.com/pdf/Impact%20of%20Diesel%20Fuel%20Injection%20SIAT%202005.pdf
• https://www.researchgate.net/publication/260643808_Particulate_emissions_from_dies
el_engines_Correlation_between_engine_technology_and_emissions