Chapter13 7EGR6 15 09

							        CHAPTER 13.7
Exhaust Gas Re-Circulation Valve
EGR Cooler
    • E – Exhaust
    • G – Gas
    • R – Recirculation
             The ABC’s Of
    Exhaust Gas Recirculation (EGR)
                  OVERVIEW
In general, the higher the engine temperature,
          the more efficient the engine.

                 Which results in:

    1) Good Performance

    2) Good Fuel Economy
                 The ABC’s Of
        Exhaust Gas Recirculation (EGR)
When peak temperatures are high enough for long
enough periods of time, the nitrogen and oxygen in the
air combine to form new compounds, primarily NO and
NO2. These are normally referred to collectively as
“NOx – Nitrogen Oxide”
                The ABC’s Of
       Exhaust Gas Recirculation (EGR)
• Too much NOx in the atmosphere contributes
  to the production of smog.
• In October of 2002, new NOx standards required the
  diesel engine industry to introduce additional
  technology to meet the new standards.
• EGR COOLER
         The ABC’s Of
Exhaust Gas Recirculation (EGR)
       How Can NOx Be Reduced?

•   Since high cylinder temperatures cause
    NOx, NOx can be reduced by lowering
    cylinder temperatures. Charge air coolers
    are already commonly used for this
    reason.

•   Reducing the amount of oxygen in the
    cylinder, inhibits the combustion process
           How Can NOx Be Reduced?

• The best way to reduce NOx is to limit the
  amount of oxygen in the cylinder. Which
  results in lower cylinder temperatures.
• This is done by recirculation of exhaust
  gas (EGR) into the cylinder.
• This technique lowers cylinder
  temperature, reducing NOx, But it also
  reduces fuel economy and performance,
  and creates excess soot.
         The ABC’s Of
Exhaust Gas Recirculation (EGR)


                • When EGR is required,
                  the engine’s electronic
                  controls open the EGR
                  valve.
1

                • Turbocharger &
                  EGR Valve (1)
Exhaust Gas Recirculation (EGR)

                 • The exhaust gases flow
                   through this pipe to the
                   EGR cooler. (2)

   2
         The ABC’s Of
Exhaust Gas Recirculation (EGR)

             • The exhaust gases are
               cooled by water from the
               engine cooling system. (3)
        3
                           The ABC’s Of
                  Exhaust Gas Recirculation (EGR)

                            • The cooled exhaust gases
                        4     then flow through the EGR
                              transfer pipe into the
                              intake manifold. (4)
                            • Which then lowers the
                              cylinder temperature
                            • Results in lower NOx
                              production.
 4

Intake Manifold
              Regeneration System
                 What is its job ?
• The system's job is to capture and burn off
  (regenerate) the particulate matter (soot) in the
  engine exhaust gas .

• It does this using a Diesel Oxidation Catalyst (DOC)
  and a Diesel Particulate Filter (DPF). By monitoring
  exhaust gas temperature and system back pressure,
  Detroit Diesel Electronic Control determines when
  and how additional help is needed to ensure
  complete regeneration of the soot captured in the
  DPF.
            Types of Regeneration

•   There are two types of Regeneration ?
1. Active
2. Stationary.
               Types of Regeneration

1. Active Regeneration
• During normal driving the Intake Throttle is
  electronically actuated to help increase the
  After treatment System temperature while the
  unit is running.

• The Dosing Valve injects a mist of diesel fuel
  into the exhaust system to further increase the
  After treatment System temperature until
  satisfactory regeneration is complete.
               Types of Regeneration
2.   Stationary Regeneration
•    Depending on engine duty or application, the
     Detroit Diesel Electronic Control (DDEC) may
     notify the driver that stationary regeneration is
     necessary.

•    After the driver begins the manual activation of
     the regeneration process, the RPM’s go up to
     1650 (High Idle is 1400 RPM’s)

•    Regeneration take about 20-30 minutes.
Stationary Regeneration Manual Activation
Manual Regeneration Switches




         Regen Request




                 Regen Inhibit
Regeneration Manual Switch Position


    Hold Regen Request Switch up for 5 – 10 sec.




                        Regen Switch UP
Regeneration Location


    Regeneration Valve
Regeneration Trouble Shooting
               References

• Detroit Diesel Engine Manual

• www.detroitdiesel.com

• Firefighter Chris Adams

 Station 13C