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D
E
4
AILY
URO
PARTICULATE FILTER REGENERATION SYSTEM
Figure 282
1. E.G.R. valve - 2. Exhaust valve - 3. Differential pressure sensor - 4. Inlet exhaust gas temperature sensor -
5. Outlet exhaust gas temperature sensor - 6. D.P.F. catalysed silencer - 7. E.D.C. 16 central unit -
A. Post-injection - B. Exhaust gasses heated by post-injection - C. Catalyst - D. Particulate filter -
Operation
Particulate filter regeneration is managed by engine E.D.C. 16
central unit. The central unit, based on the temperature of
exhaust gasses detected by sensors (5 and 4) and particulate
filter clogging grade detected by differential pressure sensor
(3), when exhaust valve (2) is closing at about 1º÷3º from
T.D.C., causes electrical injectors (8) to inject small quantities
of fuel into the cylinders. The combustion of this fuel
increases the temperature of flowing gasses.
At the same time, the central unit shuts out:
- Throttle valve (11), to prevent, at opening start, air from
entering through inlet valve (9), as air would cool
exhaust gasses;
- E.G.R. valve (1), to prevent recirculated oil vapours and
gasses produced by post-injection from being sucked
into the cylinders.
Print 603.93.651
8. Piston - 9. Inlet valve - 10. Electrical injector - 11. Throttle valve
E. Purified exhaust gasses
Exhaust gasses, so heated enter into the silencer, where,
passing through the catalyst, the pollutants they are
composed of (nitrogen oxides) are reduced or transformed
into inert substances (carbon dioxide - steam), then pass into
particulate filter where the regeneration process takes place:
exhaust gas high temperature causes the combustion of
particulate particles accumulated in the filter.
Particulate filter regeneration is realised when following
conditions are present:
- catalyst inlet exhaust gas temperature >230 ºC with the
help from post-injection;
- exhaust gas temperature in particulate filter >530 ºC with
presence of free oxygen having a percentage >8%;
- minimum time of permanence in above conditions >10'.
135
F1A ENGINE
105065
Base - March 2006
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