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2002 ISX/M/B Engines EquippedWith EGR

Cooled Exhaust Gas Recirculation

What is cooled exhaust gas recirculation?

– Exhaust gas recirculation (EGR) is where a portion of the exhaust

gas is rerouted through a cooler, and then the cooled exhaust gas

is reintroduced into fresh charge air. This mixture contains fewer

oxygen atoms per volume of charge, which reduces the flame

temperature during combustion, thus reducing emissions.

EGR Cooler

EGR Control Valve

) (

EGR Measurement

VG Control Valve

Mixing Device Venturi

VG Turbocharger

EGR System Flow

Charge Air Cooler

EGR Hardware - EGR Valve

The EGR valve regulates the amount of exhaust gas that is recirculated into the intake system.

The EGR valve is controlled by a high speed electric motor that is infinitely variable between fully open and fully closed.

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EGR Valve Internal Components

Motor Gear -mates with gear reduction

Gear reduction with clutch

Sector Gear

(Hidden in this view)

Output of “Gear reduction with clutch”

- mates with Sector Gear

Shaft for sector gear and position sensor

Flow of Exhaust Gas

Coolant passage for valve guide

Return spring to close valve if failure occurs

Poppet Valve

EGR Cooler

• Tube-and-shell design

• Stainless steel

• Self-cleaning tube design

Click the image above to play the video.

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Mixing Devices

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Variable Geometry Turbocharging

Integrated electronic controls

Improves performance– vehicle acceleration from low

speeds

– Reduces turbo-lag

– Increases engine braking power

– Allows for higher power from smaller engines

– Reduces driver shifts

Improves fuel economy

Lowers emission levels

Variable Geometry Turbocharger

Fresh Air

VG Actuation(either pneumatic or electric)

CompressorTurbine

Nozzle Ring

Yoke Mechanism

Shroud Plate

SpeedSensor

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VG Turbocharger Operation“Heron Valve” Turbo Actuator ( Latter Engines )

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EGR System Flow New EGR System Sensors

Turbo Intake Air Temperature

Turbo Speed

EGR Valve Position

Exhaust Pressure

Exhaust Temperature

Delta Pressure Sensor (EGR Flow Rate)

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EGR Gas Flow Measurement

The EGR Differential Pressure Sensor (EGR Flow Sensor) will be located on the air intake connection or in the exhaust transfer tube depending on the engine family.

The EGR Differential Pressure Sensor is used to calculate the mass flow of exhaust gas mixing with the fresh air from the charge air cooler.

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Oxygen as a function of EGR

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

1.00

15 25 35 45 55 65 75 85

fresh A/F

EG

R r

ate

(b

y m

as

s)

16% O2

17% O2

18% O2

19% O2

20% O2

Running Engine Demo

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2002 ISX Engine Equipped with EGR