DPF regeneration control device

Patent metadata

Field	Value
Publication number	US-9719440-B2
Application number	US-201415025530-A
Country	US
Kind code	B2
Filing date	Sep 8, 2014
Priority date	Sep 27, 2013
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

An object is to provide a DPF regeneration control device whereby it is possible to prevent clogging of a DOC more efficiently than conventional techniques, and to recover the DOC securely from a clogging condition even if the DOC is actually clogged. A DPF regeneration control device ( 10 ) includes: a DPF temperature-increase unit ( 10 A) including a first temperature-increase unit ( 12 ) configured to heat a DPF ( 37 ) to a predetermined temperature, and a second temperature-increase unit ( 14 ) configured to heat the DPF to a temperature higher than the predetermined temperature in cooperation with the first temperature-increase unit; a DOC clogging detection unit ( 10 D) configured to detect that a DOC ( 35 ) is clogged if a clogging parameter detected during execution of the automatic regeneration exceeds a clogging threshold value determined in advance for a predetermined period, the clogging parameter being related to clogging of the DOC, and a DOC clogging countermeasure unit ( 10 C) configured to stop the automatic regeneration and issue an alert to prompt execution of the manual regeneration, if the clogging of the DOC is detected.

First claim

The invention claimed is:

1. A diesel particulate filter (DPF) regeneration control device, provided for an exhaust-gas processing device of a diesel engine, the exhaust-gas processing device including a diesel oxidation catalyst (DOC) disposed in an exhaust channel and a DPF disposed on a downstream side of the DOC, for controlling execution of forced regeneration of heating the DPF to remove particulate matter (PM) which accumulates on the DPF, the forced regeneration comprising automatic regeneration automatically executed if a predetermined forced-regeneration execution condition is satisfied, and manual regeneration executed by manual operation to heat the DPF to a higher temperature than in the automatic regeneration, and the DPF regeneration device comprising:
a central processor to:
control a DPF temperature increase to include a first temperature increase to heat the DPF to a predetermined temperature, and a second temperature increase to heat the DPF to a temperature higher than the predetermined temperature in cooperation with the first temperature increase;
detect DOC clogging if a clogging parameter detected during execution of the automatic regeneration exceeds a clogging threshold value determined in advance for a predetermined period, the clogging parameter being related to clogging of the DOC;
stop the automatic regeneration via DOC clogging countermeasures and issue an alert to prompt execution of the manual regeneration, if the clogging of the DOC is detected;
detect that the DOC is in an initial stage of clogging if the clogging parameter detected during the automatic regeneration is not greater than the clogging threshold value and greater than a second clogging threshold value smaller than the clogging threshold value for a predetermined period, or if the clogging parameter is not greater than the clogging threshold value and a change amount of the clogging parameter is greater than a change-amount threshold value set in advance for a predetermined period; and
execute DOC clogging initial stage countermeasures to control the first temperature increase for a predetermined period after completion of the automatic regeneration if the DOC is detected to be in the initial stage of the clogging.

2. The DPF regeneration control device according to claim 1 , wherein control of the first temperature increase comprises at least one of:
control of a throttle valve to control an opening degree of a throttle valve disposed in an intake channel,
control of early post injection control to control a fuel injection amount of early post injection of injecting fuel after a time of main combustion injection, or
control of rail-pressure to control a rail pressure at which the fuel is injected, and
wherein control of the second temperature increase comprises:
control of late post injection to control a fuel injection amount of late post injection of injecting fuel at a timing which does not contribute to combustion in a combustion chamber after the early post injection, or
control of exhaust-duct injection to control a fuel injection amount of exhaust-duct injection of injecting fuel to an exhaust channel on an engine downstream side.

3. The DPF regeneration control device according to claim 2 ,
wherein the clogging parameter is to be set on the basis of a temperature difference between an outlet temperature and an inlet temperature of the DOC, a flow rate of exhaust gas flowing through the DOC, and a fuel-injection amount of the late post injection or the exhaust-duct injection.

4. The DPF regeneration control device according to claim 2 ,
wherein control of the late post injection or control of the exhaust-duct injection is to control a fuel injection amount so that an inlet temperature of the DPF is to reach a target temperature required to execute the forced regeneration, and
wherein the clogging parameter is to be set
on the basis of a cumulative fuel-injection amount of the late post injection or the exhaust-duct injection while an inlet temperature of the DPF is to increase by a predetermined temperature, and a cumulative fuel-injection amount of the late post injection or the exhaust-duct injection while the inlet temperature of the DPF increases by the predetermined temperature in an initial state in which the DOC is not clogged, or
on the basis of a mean injection amount of the late post injection or the exhaust-duct injection in a stable state in which the inlet temperature of the DPF is to have reached a target control temperature, and a mean injection amount of the late post injection or the exhaust-duct injection of injecting in a stable state in which the inlet temperature of the DPF is to have reached a target control temperature in an initial state in which the DOC is not clogged.

5. The DPF regeneration control device according to claim 2 ,
wherein control of the late post injection or control of the exhaust-duct injection is to control a fuel injection amount so that an inlet temperature of the DPF is to reach a target temperature required to execute the forced regeneration, and
wherein the clogging parameter is to comprise at least two of:
a clogging parameter to be set on the basis of a temperature difference between an inlet temperature of the DPF and an outlet temperature of the DPF;
a clogging parameter to be set as an outlet temperature of the DPF;
a clogging parameter to be set on the basis of a temperature difference between an outlet temperature and an inlet temperature of the DOC, a flow rate of exhaust gas flowing through the DOC, and a fuel-injection amount of the late post injection or the exhaust-duct injection;
the clogging parameter to be set on the basis of an increase speed of the inlet temperature of the DPF, and an increase speed of the inlet temperature of the DPF in an initial state in which the DOC is not clogged; and
a clogging parameter to be set on the basis of a cumulative fuel-injection amount of the late post injection or the exhaust-duct injection of injecting while an inlet temperature of the DPF is to increase by a predetermined temperature, and a cumulative fuel-injection amount of the late post injection or the exhaust-duct injection of injecting while the inlet temperature of the DPF is to increase by the predetermined temperature in an initial state in which the DOC is not clogged, or on the basis of a mean injection amount of the late post injection or the exhaust-duct injection in a stable state in which the inlet temperature of the DPF is to have reached a target control temperature, and a mean injection amount of the late post injection or the exhaust-duct injection of injecting in a stable state in which the inlet temperature of the DPF is to have reached a target control temperature in an initial state in which the DOC is not clogged.

6. The DPF regeneration control device according to claim 1 ,
wherein the clogging parameter is to be set on the basis of a temperature difference between an inlet temperature of the DPF and an outlet temperature of the DPF.

7. The DPF regeneration control device according to claim 1 ,
wherein the clogging parameter is to be set as an outlet temperature of the DPF.

8. The DPF regeneration control device according to claim 1 ,
wherein the clogging parameter is to be set on the basis of an increased speed of an inlet temperature of the DPF, and
an increase speed of the inlet temperature of the DPF in an initial state in which the DOC is not clogged.

9. A diesel particulate filter (DPF) regeneration control device, provided for an exhaust-gas processing device of a diesel engine, the exhaust-gas processing device including a diesel oxidation catalyst (DOC) disposed in an exhaust channel and a DPF disposed on a downst

Assignees

• Mitsubishi Heavy Ind Ltd

Inventors

• Nishizawa Kazuki
• Yamada Tomohide
• Sato Daisuke

Classifications

• F01N3/023

  using means for regenerating the filters, e.g. by burning trapped particles · CPC title

• Y02T10/44

  Cross-Sectional Technologies · mapped topic

• Y02T10/26

  Cross-Sectional Technologies · mapped topic

• F02D41/405

  with post injections · CPC title

• F02D41/029 Primary

  the exhaust gas treating apparatus being a particulate filter · CPC title