JP6270583B2 - Engine exhaust treatment equipment - Google Patents

Description

  The present invention relates to an engine exhaust treatment apparatus, and more particularly to an engine exhaust treatment apparatus capable of reliably warming up a combustion catalyst.

  Conventionally, as an exhaust treatment device for an engine, a combustible gas generator, a combustion catalyst, an exhaust treatment unit, and a control device are provided, and a combustion catalyst combustion gas is generated by the combustible gas generator under the control of the control device. Combustion gas is mixed into the exhaust gas passing through the engine exhaust path, catalytically combusted with a combustion catalyst, and exhaust gas whose temperature has been raised by this catalytic combustion is supplied to the exhaust processing unit (for example, , See Patent Document 1).

  According to this type of exhaust treatment device, even when the exhaust temperature is low, there is an advantage that the exhaust treatment can be promoted in the exhaust treatment unit by raising the temperature of the exhaust by catalytic combustion of the combustible gas.

  However, in this type of exhaust treatment device, when the combustion catalyst is not warm enough, the combustion catalyst is not activated and catalytic combustion does not occur.

JP 2012-188972 A (see FIG. 2)

<< Problem >> The exhaust treatment in the exhaust treatment unit may not be sufficiently promoted.
In this type of exhaust treatment device, if the combustion catalyst is not sufficiently warmed up, the combustion catalyst is not activated, catalytic combustion does not occur, and the exhaust treatment in the exhaust treatment unit is not sufficiently promoted. Sometimes.

  An object of the present invention is to provide an engine exhaust treatment device capable of reliably warming up a combustion catalyst.

Invention specific matters of the invention according to claim 1 are as follows.
As illustrated in FIG. 1, a combustible gas generator (1), a combustion catalyst (2), a DPF (3), and a control device (4) are provided.
As illustrated in FIGS. 1 and 2, in the regeneration process of the DPF (3), the combustible gas generator (1) is set to obtain a predetermined target reaction temperature under the control of the control device (4) . Combustion catalyst combustion gas (5) is generated (S10) from the air-fuel mixture (16) of the mixture ratio by the catalytic reaction of the gas generation catalyst (10) , and this combustion catalyst combustion gas (5) is generated in the engine exhaust path. The exhaust gas (7) passing through (6) is mixed into the exhaust gas (7) and is catalytically combusted by the combustion catalyst (2), and the exhaust gas (7) heated by this catalytic combustion is supplied to the DPF (3). In an engine exhaust treatment device,
As illustrated in FIGS. 1 and 2, in the regeneration process of the DPF (3), the combustible gas generator (1) is generated by the control device (4) before the combustion catalyst combustion gas (5) is generated (S10). ) , The combustion catalyst warming gas (8) is generated by the catalytic reaction of the gas generating catalyst (10) from the air-fuel mixture (16) having a mixture ratio set so as to obtain a predetermined target reaction temperature (S6). The combustion catalyst warm-up gas (8) is mixed into the exhaust (7) passing through the engine exhaust path (6) and ignited by the ignition device (9) upstream of the combustion catalyst (2). Combustion catalyst (2) is warmed up by the heated exhaust (7),
When the warm-up end condition of the combustion catalyst (2) is satisfied, the combustion catalyst combustion gas (5) is generated (S10).
As illustrated in FIGS. 1 and 2, when the combustion catalyst warming gas (8) is generated (S6), the combustible gas is generated more than when the combustion catalyst combustion gas (5) is generated (S10). By setting the target reaction temperature of the gas generating catalyst (10) of the generator (1) to be higher, the ignitability of the combustion catalyst warming gas (8) is higher than that of the combustion catalyst combustion gas (5). Configured,
As illustrated in FIG. 1 to FIG. 3, a PM accumulation amount estimation device that estimates an estimated PM accumulation amount of the combustion catalyst (2) and the DPF (3) based on the exhaust pressure upstream of the combustion catalyst (2) ( 12), and when the PM accumulated amount estimation value reaches the regeneration necessary value that requires regeneration of either the DPF (3) or the combustion catalyst (2), the DPF (3) or combustion catalyst ( When the interval from the end of regeneration in any of 2) to the current regeneration required value is less than a predetermined time, the regeneration requirement condition for the combustion catalyst (2) is satisfied, and the regeneration process for the combustion catalyst (2) is performed. When the regeneration requirement condition for the combustion catalyst (2) is not satisfied, the regeneration process for the DPF (3) is performed,
In the regeneration process of the combustion catalyst (2), the controller (4) causes the combustion catalyst regeneration gas (16) from the air-fuel mixture (16) by the catalytic reaction of the gas generation catalyst (10) in the combustible gas generator (1). 13) is generated (S13), and this combustion catalyst regeneration gas (13) is mixed into the exhaust (7) passing through the engine exhaust path (6), ignited by the ignition device (9), and then increased by flame combustion. An exhaust treatment apparatus for an engine, characterized in that the PM deposited on the combustion catalyst (2) is incinerated and removed by the heated exhaust gas (7) to regenerate the combustion catalyst (2).

(Invention of Claim 1)
The invention according to claim 1 has the following effects.
<Effect> It is possible to reliably warm up the combustion catalyst.
Since the ignitability of the combustion catalyst warming gas (8) is higher than that of the combustion catalyst combustion gas (5), the ignition failure of the combustion catalyst warming gas (8) is suppressed, and the combustion catalyst The warm-up of (2) can be performed reliably.

<< Effect >> Even if PM accumulates on the combustion catalyst, the function of the combustion catalyst can be recovered.
As illustrated in FIGS. 1 and 2, the PM accumulated on the combustion catalyst (2) is incinerated and removed by the exhaust gas (7) heated by flame combustion, and the combustion catalyst (2) is regenerated. Therefore, even if PM accumulates on the combustion catalyst (2), the function of the combustion catalyst (2) can be recovered.

(Invention of Claim 2 )
The invention according to claim 2 has the following effect in addition to the effect of the invention according to claim 1 .
<Effect> The function of the combustion catalyst can be reliably recovered.
As illustrated in FIGS. 1 and 2, since the ignitability of the reignition gas (15) is higher than that of the combustion catalyst regeneration gas (13), the reignition gas (15) The failure of ignition is suppressed, and the function of the combustion catalyst (2) can be reliably restored by the regeneration process of the combustion catalyst (2).
(Invention of Claim 3)
The invention according to claim 3 has the following effect in addition to the effect of the invention according to claim 1 or claim 2.
<Effect> It is possible to reliably warm up the combustion catalyst.
As illustrated in FIGS. 1 and 2, since the ignition device (9) is preheated before the combustion catalyst warm-up gas (8) is generated (S6), the combustion catalyst warm-up is performed. Failure of ignition of the working gas (8) is suppressed, and the combustion catalyst (2) can be warmed up reliably.

It is a mimetic diagram of an engine exhaust treatment device concerning an embodiment of the present invention. It is a flowchart of the process by the exhaust processing apparatus of FIG. 2 is a time chart of DPF regeneration and combustion catalyst regeneration by the exhaust treatment device of FIG. 1.

  1 to 3 are diagrams for explaining an exhaust treatment device for an engine according to an embodiment of the present invention. In this embodiment, an exhaust treatment device for a diesel engine will be explained.

The outline of this exhaust treatment apparatus is as follows.
As shown in FIG. 1, the exhaust treatment device includes a combustible gas generator (1), a combustion catalyst (2), a DPF (3), and a control device (4).
As shown in FIGS. 1 and 2, in the regeneration process of the DPF (3), the mixture set to obtain a predetermined target reaction temperature in the combustible gas generator (1) under the control of the control device (4). The combustion catalyst combustion gas (5) is generated (S10 ) from the air / fuel mixture (16) having a specific ratio by the catalytic reaction of the gas generation catalyst (10) , and this combustion catalyst combustion gas (5) is generated in the engine exhaust path ( 6) mixed with the exhaust gas (7) passing through, and catalytically combusted by the combustion catalyst (2), and the exhaust gas (7) heated by this catalytic combustion is supplied to the DPF (3). Yes.

As shown in FIG. 1, a combustible gas generator (1) generates a combustible gas such as a combustion catalyst combustion gas (5) from an air-fuel mixture (16) by a catalytic reaction of a gas generating catalyst (10). To do.
A gas generating catalyst (10) is accommodated in the combustible gas generator (1), and an air / fuel mixing chamber (25) is provided on the upper part thereof. An air-fuel mixture inlet (21) is provided in the upper central portion of the gas generating catalyst (10) so as to be recessed downward. The air / fuel mixing chamber (25) is supplied with liquid fuel (17) and air (18) and mixed to form an air / fuel mixture (16). 10). A gas generation start catalyst (22) is accommodated in the gas mixture inlet (21), and a heater (11) is inserted therein. The temperature sensor (26) is inserted in the gas generation catalyst (10).
The gas generating catalyst (10) is a woven iron chrome wire, and the rhodium catalyst component is supported on the iron chrome wire. The gas generation start catalyst (22) is an alumina fiber mat, on the surface of which a rhodium catalyst component is supported. The gas generation start catalyst (22) has higher retention of the liquid fuel (17) than the gas generation catalyst (10).
Light oil is used for the liquid fuel (17).

The combustion catalyst (2) is DOC. DOC is an abbreviation for diesel oxidation catalyst.
DPF is an abbreviation for diesel particulate filter, and traps PM in the exhaust (7).
The control device (4) is an engine ECU and is a microcomputer. ECU is an abbreviation for electronic control unit.

The features of the exhaust treatment device are as follows.
As shown in FIGS. 1 and 2, in the regeneration process of the DPF (3), the combustible gas generator (1) is generated by the controller (4) before the combustion catalyst combustion gas (5) is generated (S10). Thus, the combustion catalyst warming gas (8) is generated (S6) by the catalytic reaction of the gas generating catalyst (10) from the air-fuel mixture (16) having a mixture ratio set so as to obtain a predetermined target reaction temperature. The combustion catalyst warm-up gas (8) is mixed into the exhaust (7) passing through the engine exhaust path (6), ignited by the ignition device (9) upstream of the combustion catalyst (2), and rises by flame combustion. The combustion catalyst (2) is configured to be warmed up by the heated exhaust gas (7).
When the warm-up termination condition for the combustion catalyst (2) is satisfied, the combustion catalyst combustion gas (5) is generated (S10).
The ignition device (9) is a glow plug.
In addition to the combustion catalyst combustion gas (5), the combustion catalyst warming gas (8), the combustion catalyst regeneration gas (13), and the reignition gas (15), which will be described later, are provided upstream of the ignition device (9). Secondary air (27) is mixed.

When the warm-up termination condition of the combustion catalyst (2) is satisfied, the following is performed.
As shown in FIGS. 1 and 2, the establishment of the combustion catalyst (2) warm-up termination condition is defined as a case where either the first condition or the second condition is satisfied, and the first condition is the combustion catalyst (2). The inlet temperature (T0) of the combustion catalyst is equal to or higher than the activation required temperature (t0) of the combustion catalyst (2), and the outlet temperature (T1) of the combustion catalyst (2) exceeds the inlet temperature (T0) of the combustion catalyst (2) It is assumed that the temperature is higher than the activation confirmation temperature (t1) of the combustion catalyst (2), and the second condition is that the warm-up confirmation temperature (t1 ′) of the combustion catalyst (2) set higher as the engine speed is lower. ) When the outlet temperature (T1) of the combustion catalyst (2) continuously exceeds a predetermined time.
For this reason, the first condition in which the activation of the combustion catalyst (2) can be directly confirmed by the inlet temperature (T0) and the outlet temperature (T1) of the combustion catalyst (2), and the combustion catalyst (2 ) Exit temperature (T1), the second condition that ensures the activation temperature of the combustion catalyst (2) is ensured, the combustion catalyst (2) is activated, and the warm-up combustion catalyst (2) is warmed up. The machine can be performed reliably.

As shown in FIG. 1, the inlet temperature (T0) of the combustion catalyst (2) is detected by an exhaust temperature sensor (19) at the inlet of the combustion catalyst (2). The outlet temperature (T1) of the combustion catalyst (2) is detected by an exhaust temperature sensor (20) at the outlet of the combustion catalyst (2). The activation required temperature (t0) is a lower limit temperature at which the combustion catalyst (2) is activated and the combustion catalyst combustion gas (5) can be catalytically combusted. The activation confirmation temperature (t1) is the lower limit temperature at the outlet when the combustion catalyst (2) is activated, and is the temperature obtained by adding the activation rising temperature (α) to the inlet temperature (T1) of the combustion catalyst (2). is there. The activation increase temperature (α) is the exhaust increase temperature expected in the catalytic combustion of the combustion catalyst warm-up gas (8) when the combustion catalyst (2) is activated.
The warm-up confirmation temperature (t1 ') is the lower limit temperature at the outlet of the combustion catalyst (2) when the combustion catalyst (2) is activated regardless of the inlet temperature (T0 ) of catalytic combustion (2), and the engine speed It is set to be higher as the value is lower. When the engine speed decreases, the fuel injection amount per unit time decreases, the temperature of the exhaust (7) decreases, and the heat accumulated in the combustion catalyst (2) is taken away, so the warm-up confirmation temperature (t1 ' ) Is set high to ensure that the temperature of the combustion catalyst (2) can be maintained at the activation temperature even if heat is taken away. The warm-up confirmation temperature (t1 ′) according to the engine speed is obtained by experiment and mapped. The warm-up confirmation temperature (t1 ′) is set to a temperature higher than the activation required temperature (t0).

As shown in FIGS. 1 and 2, when the combustion catalyst warming gas (8) is generated (S6), combustible gas is generated more than when the combustion catalyst combustion gas (5) is generated (S10). The ignitability of the combustion catalyst warming gas (8) is higher than that of the combustion catalyst combustion gas (5) by setting the target reaction temperature of the gas generating catalyst (10) of the vessel (1) high. Has been.
When the target reaction temperature of the gas generating catalyst (10) of the combustible gas generator (1) is set high, the combustible gas is reduced in molecular weight by thermal decomposition, and the ignitability is increased.
In order to increase the reaction temperature of the gas generating catalyst (10), the mixture ratio of the air-fuel mixture (16) may be made rich in air.

As shown in FIGS. 1 and 2, the combustible gas generator (1) includes a heater (11), and before the combustion catalyst warm-up gas (8) is generated (S6) by the gas generation catalyst (10). In addition, the gas generating catalyst (10) is warmed up by the heat generated by the heater (11) by the control device (4).
As shown in FIG. 2, the energization of the heater (11) is terminated (S4) after a predetermined time has elapsed after the energization of the heater (11) is started (S2). Before the combustion catalyst warm-up gas (8) is generated (S6) by energizing the ignition device (9) by the control device (4) before (S6), the ignition device (9 ) Is preheated.

As shown in FIG. 1, a PM accumulation amount estimation device (12) for the combustion catalyst (2) is provided.
As shown in FIGS. 1 and 2, when a predetermined combustion catalyst regeneration requirement condition based on the estimated PM accumulation amount of the combustion catalyst (2) is satisfied, the regeneration process of the combustion catalyst (2) is performed. In the regeneration process of the combustion catalyst (2), the control device (4) uses the combustible gas generator (1) to generate gas from the air / fuel mixture (16) having a mixture ratio set so as to obtain a predetermined target reaction temperature. A combustion catalyst regeneration gas (13) is produced (S13) by the catalytic reaction of the produced catalyst (10) , and this combustion catalyst regeneration gas (13) is mixed into the exhaust (7) passing through the engine exhaust path (6). The PM deposited on the combustion catalyst (2) is burned and removed by the exhaust (7) ignited by the ignition device (9) and heated by flame combustion so that the combustion catalyst (2) is regenerated. It is configured.

As shown in FIG. 1, the ignition state detection device (14) of the ignition device (9) is provided.
As shown in FIGS. 1 and 2, when the ignition state detection device (14) detects that the combustion catalyst regeneration gas (13) is not ignited, the control device (4) generates flammable gas. When the reignition gas (15) is generated (S17) in the vessel (1) and the combustion catalyst reignition gas (15) is generated, the combustion catalyst regeneration gas (13) is generated (S13). The target reaction temperature of the gas generating catalyst (10) of the combustible gas generator (1) is set to be higher than the case, so that the ignitability of the reignition gas (15) is improved by the combustion catalyst regeneration gas (13). It is configured to be higher than that.
When the target reaction temperature of the gas generating catalyst (10) of the combustible gas generator (1) is set high, the combustible gas is reduced in molecular weight by thermal decomposition, and the ignitability is increased.
In order to increase the reaction temperature of the gas generating catalyst (10), the mixture ratio of the air-fuel mixture (16) may be made rich in air.

The processing flow of this exhaust treatment device is as follows.
In step (S1), it is determined whether or not the reproduction request condition is satisfied. If the determination is affirmative, the process proceeds to step (S2). If the determination is negative, the determination in step (S1) is repeated.
As shown in FIG. 3, the regeneration requirement condition is satisfied when the estimated PM accumulated amount reaches a regeneration required value. When this regeneration request condition is satisfied, it is not determined whether the regeneration request is for the DPF or the combustion catalyst (2), and this determination is performed in a later step (S9).
The PM deposition amount estimation value is estimated by the PM deposition amount estimation device (12) based on the exhaust pressure upstream of the combustion catalyst (2). The exhaust pressure is detected by an exhaust pressure sensor (23). The PM accumulation amount estimation device (12) is an arithmetic processing unit of the control device (4).
In step (S2), energization of the heater (11) of the gas generating catalyst (10) is started, and the process proceeds to step (S3).
In step (S3), energization of the ignition device (9) is started, and the process proceeds to step (S4).
In step (S4), the energization of the gas generation catalyst (10) to the heater (11) is terminated based on the elapse of a predetermined time from the start of energization in step (S2), and the process proceeds to step (S5). To do.
In step (S5), it is determined whether or not the gas generation catalyst temperature (T3) is equal to or higher than the gas generation required temperature (t3). If the determination is affirmative, the warm-up ends and the process proceeds to step (S6). If the determination is negative, the process returns to step (S2).
If the ignition of the combustion catalyst warm-up gas (8) is detected by the ignition state detection device (14) after energization of the ignition device (9) is started in step (S3), the ignition device ( The energization of 9) may be terminated, and even if the ignition device (9) no longer generates heat, the flame combustion of the combustion catalyst warm-up gas (8) continues, and the ignition generated in step (S10) described later. The combustion flame is blown out when it comes in contact with the combustion catalyst combustion gas (5) having low properties.

In step (S6), combustion catalyst warm-up gas (8) is generated, and the process proceeds to step (S7).
In step (S7), the first condition of the warm-up termination condition of the combustion catalyst (2), that is, the inlet temperature (T0) of the combustion catalyst (2) is equal to or higher than the activation required temperature (t0), and the combustion catalyst (2 ) Outlet temperature (T1) is determined to be equal to or higher than the activation confirmation temperature (t1). If the determination is affirmative, the process proceeds to step (S9).
If the determination in step (S7) is negative, the process proceeds to step (S8) and the second condition of the warm-up termination condition of the combustion catalyst (2), that is, the outlet temperature (T1) of the combustion catalyst (2). Is determined to continue to exceed the warm-up confirmation temperature (t1 ′) for a predetermined time. If the determination is affirmative, the process proceeds to step (S9). If the determination is negative, the process returns to step (S6).

In step (S9), it is determined whether or not the regeneration requirement condition for the combustion catalyst (2) is satisfied. If the determination is affirmative, the process proceeds to step (S10), and the exhaust treatment device section (3). The regeneration of a certain DPF is started. When determination is denied, it transfers to step (S13) and regeneration of a combustion catalyst (2) is started.
As shown in FIG. 3, the regeneration requirement condition of the combustion catalyst (2) is established when the interval (24) from the end of the previous regeneration to the establishment of the current regeneration requirement condition is less than a predetermined time.
The PM deposited on the DPF is almost completely removed by one DPF regeneration process or one combustion catalyst regeneration process, but the PM deposited on the combustion catalyst (2) is not removed by multiple DPF regeneration processes. This is because, since it is gradually accumulated, when the interval (24) becomes less than a predetermined time, it can be estimated that a predetermined amount of PM necessary for regeneration of the combustion catalyst (2) is accumulated. .
In step (S10), combustion catalyst combustion gas (5) is generated, and the process proceeds to step (S11). In step (S11), it is determined whether the DPF regeneration end condition is satisfied. If the determination is affirmative, the process proceeds to step (S12).
The DPF regeneration end condition is satisfied when the DPF inlet temperature (combustion catalyst outlet temperature) is equal to or higher than a predetermined temperature and a predetermined time has elapsed.
In step (S12), the regeneration of the DPF ends and the process ends.
The regeneration of the DPF is completed by stopping the generation of the combustion catalyst combustion gas (5).

In step (S13), combustion catalyst regeneration gas (13) is generated, and the process proceeds to step (S14).
In step (S14), it is determined whether or not the combustion catalyst regeneration gas (13) is in an ignition state. If the determination is affirmative, the process proceeds to step (S15). If the determination in step (S14) is negative, the process proceeds to step (S16).
In step (S16), energization of the ignition device (9) is resumed, and the process proceeds to step (S17).
In step (S17), the reignition gas (15) is generated, and the process returns to step (S14).
In step (S16), it is determined whether or not the regeneration end condition for the combustion catalyst (2) is satisfied. If the determination is affirmative, the process proceeds to step (S18).
The regeneration end condition of the combustion catalyst (2) is satisfied when the inlet temperature of the combustion catalyst (2) is equal to or higher than a predetermined temperature and a predetermined time has elapsed.
In step (S18), the regeneration of the combustion catalyst (2) is finished, and the process is finished.
The regeneration of the combustion catalyst (2) is completed by stopping the production of the combustion catalyst regeneration gas (13).
In addition, after the energization of the ignition device (9) is restarted in step (S16), when the ignition of the re-ignition gas (15) is detected by the ignition state detection device (14), the ignition device (9) However, even if the ignition device (9) no longer generates heat, the combustion flame of the reignition gas (15) is taken over by the combustion catalyst regeneration gas (13) and the flame combustion continues.
That is, in this embodiment, a PM accumulation amount estimation device (12) for estimating the PM accumulation total amount estimated values of the combustion catalyst (2) and the DPF (3) based on the exhaust pressure upstream of the combustion catalyst (2) is provided. When the estimated PM total amount reaches the regeneration required value that requires regeneration of either DPF (3) or combustion catalyst (2), either DPF (3) or combustion catalyst (2) performed last time When the interval from the end of the regeneration to the current regeneration required value is less than the predetermined time, the regeneration requirement condition of the combustion catalyst (2) is satisfied, the regeneration process of the combustion catalyst (2) is performed, and the combustion If the regeneration requirement condition for the catalyst (2) is not satisfied, the regeneration process for the DPF (3) is performed.

(1) Combustible gas generator
(2) Combustion catalyst
(3) DPF
(4) Control device
(5) Combustion catalyst combustion gas
(6) Engine exhaust path
(7) Exhaust
(8) Gas for combustion catalyst warm-up
(9) Ignition device
(10) Gas generating catalyst
(11) Heater
(12) PM accumulation amount estimation device
(13) Gas for regeneration of combustion catalyst
(14) Ignition state detection device
(15) Re-ignition gas
(S2) Energization of the heater starts
(S3) Energization of the ignition device starts
(S4) Energization of the heater ends
(S6) Combustion catalyst warm-up gas is generated
(S10) Combustion catalyst combustion gas is generated
(S13) Combustion catalyst regeneration gas is generated
(S18) Combustion catalyst re-ignition gas is generated

Claims (3)

Combustible gas generator (1), combustion catalyst (2), DPF (3), and controller (4)
In the regeneration process of the DPF (3), from the air-fuel mixture (16) having a mixture ratio set so as to obtain a predetermined target reaction temperature in the combustible gas generator (1) under the control of the control device (4). By the catalytic reaction of the gas generating catalyst (10), combustion catalyst combustion gas (5) is generated (S10), and this combustion catalyst combustion gas (5) is sent to the exhaust (7) passing through the engine exhaust path (6). In an exhaust treatment device for an engine configured to be mixed and catalytically combusted by a combustion catalyst (2), and an exhaust gas (7) heated by the catalytic combustion is supplied to a DPF (3),
In the regeneration process of the DPF (3) , a predetermined target reaction temperature is obtained by the combustible gas generator (1) by the controller (4) before the combustion catalyst combustion gas (5) is generated (S10). The combustion catalyst warming gas (8) is generated (S6) by the catalytic reaction of the gas generating catalyst (10) from the air / fuel mixture (16) having the mixture ratio set as described above , and this combustion catalyst warming gas (8 ) Is mixed into the exhaust (7) passing through the engine exhaust path (6), ignited by the ignition device (9) upstream of the combustion catalyst (2), and combusted by the exhaust (7) heated by flame combustion (2) is configured to be warmed up,
When the warm-up end condition of the combustion catalyst (2) is satisfied, the combustion catalyst combustion gas (5) is generated (S10).
When the combustion catalyst warming gas (8) is generated (S6), the gas generating catalyst (10) of the combustible gas generator (1) is produced more than when the combustion catalyst combustion gas (5) is generated (S10). ) Is set higher so that the ignitability of the combustion catalyst warming gas (8) is higher than that of the combustion catalyst combustion gas (5) ,
A PM accumulation amount estimation device (12) for estimating the PM accumulation amount estimation value of the combustion catalyst (2) and the DPF (3) based on the exhaust pressure upstream of the combustion catalyst (2) is provided, and the PM accumulation amount estimation value is When the regeneration required value that requires regeneration of either the DPF (3) or the combustion catalyst (2) is reached, this time from the end of regeneration of either the DPF (3) or the combustion catalyst (2) performed last time When the interval to reach the regeneration required value is less than the predetermined time, the regeneration requirement condition of the combustion catalyst (2) is established, the regeneration process of the combustion catalyst (2) is performed, and the regeneration requirement condition of the combustion catalyst (2) is If not established, DPF (3) regeneration processing is performed,
In the regeneration process of the combustion catalyst (2), the control device (4) uses the combustible gas generator (1) to generate gas from the air / fuel mixture (16) having a mixture ratio set to obtain a predetermined target reaction temperature. A combustion catalyst regeneration gas (13) is produced (S13) by the catalytic reaction of the produced catalyst (10) , and this combustion catalyst regeneration gas (13) is mixed into the exhaust (7) passing through the engine exhaust path (6). The PM deposited on the combustion catalyst (2) is burned and removed by the exhaust (7) ignited by the ignition device (9) and heated by flame combustion so that the combustion catalyst (2) is regenerated. An exhaust processing apparatus for an engine, characterized in that it is configured. The engine exhaust treatment apparatus according to claim 1 ,
An ignition state detection device (14) of the ignition device (9),
When the ignition state detection device (14) detects that the combustion catalyst regeneration gas (13) is not ignited, the control device (4) uses the combustible gas generator (1) to perform a predetermined target reaction. A reignition gas (15) is generated (S17) from the air-fuel mixture (16) having a mixture ratio set to obtain a temperature by the catalytic reaction of the gas generation catalyst (10), and the reignition gas (15 ) Is generated, the target reaction temperature of the gas generating catalyst (10) of the combustible gas generator (1) is set higher than when the combustion catalyst regeneration gas (13) is generated (S13). Thus, the engine exhaust treatment apparatus is configured such that the ignitability of the reignition gas (15) is higher than that of the combustion catalyst regeneration gas (13). The engine exhaust treatment apparatus according to claim 1 or 2 ,
The combustible gas generator (1) includes a heater (11), and before the combustion catalyst warm-up gas (8) is generated (S6) by the gas generation catalyst (10), the heater ( 11) The gas generating catalyst (10) is warmed up by the heat generated in (11),
The energization of the heater (11) is terminated (S4) after a predetermined time has elapsed since the energization of the heater (11) is started (S2), but before the end (S4), the control device (4 ) Is started (S3) so that the ignition device (9) is preheated before the combustion catalyst warm-up gas (8) is generated (S6). An exhaust processing apparatus for an engine, characterized in that it is configured.

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