JPH07332066A - Exhaust emission control device of diesel engine - Google Patents

Abstract

PURPOSE:To provide an exhaust emission control device of a diesel engine, capable of high efficiently and safely burning and regenerating a particulate trapping part through a process of decreasing thermal stress to the particulate trapping part, and excellent for reliability, economy, productivity and operation controllability. CONSTITUTION:Carbon dioxide gas sensors 22a, 32b are provided in a system, and a combustion starting judging part is provided, for comparing concentration information for showing the concentration of carbon dioxide gas detected by the carbon dioxide gas sensors 22a, 22b in burning and regenerating particulate trapping parts 4a, 4b with previously stored specific concentration information by a control, unit 19', so as to judge the combustion start of particulates of the particulate trapping parts 4a, 4b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention collects particulates (combustible fine particles such as soot) discharged from a diesel engine, and burns the collected particulates to discharge the diesel engine to the atmosphere. The present invention relates to an exhaust gas purifying device for a diesel engine that reduces the amount of particulates that are generated.

[0002]

2. Description of the Related Art In recent years, particulate matter contained in the exhaust gas of diesel engines has begun to be regulated for environmental protection and health reasons. Correspondingly, as a technique for purifying (or filtering) exhaust gas, a method is known in which a ceramic honeycomb filter (hereinafter referred to as a filter) is attached in the middle of an exhaust pipe to filter particulates. This method has a certain degree (for example, the degree to which the performance of the diesel engine body, the mission, etc. is not deteriorated due to the accumulation of particulates on the filter and the rise in the gas pressure in the exhaust pipe). Is deposited, burned by burning it, converted into carbon dioxide gas and released into the atmosphere, and the filter is cleanly regenerated and repeatedly used. Generally, this work is burned and regenerated (or regenerated).
Is called. Since the temperature of the exhaust gas discharged from the diesel engine is lower than the temperature at which the particulates start to burn, the electric heater is used for heating, burner heating, microwave heating, and the like. In addition, in order to operate the diesel engine for a long time, the exhaust pipe is branched in parallel from the middle, a filter is attached to each of the branch pipes, one filter burns the particulates, and the other filter purifies the exhaust gas. Alternately repeat,
The method is adopted.

An exhaust gas purifying apparatus for a conventional diesel engine will be described below with reference to the drawings. FIG. 6 is a schematic diagram showing a schematic configuration of a conventional exhaust gas purification apparatus for a diesel engine. Reference numeral 1 is an exhaust pipe connected to a diesel engine, 2 is a predetermined sidewall of the exhaust pipe 1, which is substantially orthogonal to the exhaust pipe 1 in order to supply the exhaust gas exhausted from the exhaust pipe 1 to second air supply pipes 3a and 3b described later. First flue, 3 communicating with each other
a and 3b are second passages respectively connected to both ends of the first air supply pipe 2 in order to deliver the exhaust gas sent from the first air supply pipe 2 to the particulate collection portions 4a and 4b described later. The air supply pipes 4a and 4b are connected to the ends of the second air supply pipes 3a and 3b in order to purify the exhaust gas sent from the second air supply pipes 3a and 3b by a filter that stores the exhaust gas inside. The particulate collection parts 5a, 5b are provided on the downstream side of the particulate collection parts 4a, 4b in order to discharge the purified gas purified by the particulate collection parts 4a, 4b to a second discharge pipe 6 described later. The first discharge pipes 6 respectively communicated with the end portions, 6 are the first discharge pipes 5a, 5
Purified gas exhaust pipe 7 which will be described later with the purified gas discharged from b.
To discharge the purified gas discharged from the second exhaust pipe 6 to the atmosphere. 2, a purified gas exhaust pipe communicating with a predetermined portion of the side wall of the exhaust pipe 6, 8a,
Reference numeral 8b denotes a second air supply pipe 3a, for supplying air for particulate combustion to the particulate collection units 4a, 4b from an air supply unit 14 described later when the particulate collection units 4a, 4b are burned and regenerated. The air supply pipes 9a and 9b respectively communicate with predetermined portions of the side wall of 3b, and the combustion gas discharged from the particulate traps 4a and 4b when the particulate traps 4a and 4b are regenerated by burning into the atmosphere. First discharge pipes 5a, 5b for discharging to
Air discharge pipes 10 communicated with predetermined portions of the side wall of the
a and 10b are air supply valves arranged near both ends of the first air supply pipe 2, 11a and 11b are discharge valves arranged near both ends of the second discharge pipe 6, and 12a and 12b are air. Supply pipe 8
air supply valves 13a, 1 respectively disposed on a and 8b
3b is an air exhaust valve provided in each of the air exhaust pipes 9a and 9b, and 14 is an air pump that supplies air with a predetermined air flow rate to the particulate traps 4a and 4b through the air supply pipes 8a and 8b. An air supply unit consisting of 15
a and 15b are exhaust gas sent to the particulate collection parts 4a and 4b and the particulate collection parts 4a and 4b.
a differential pressure sensor for detecting differential pressure information such as the differential pressure of the purified gas discharged from b, and 16a and 16b are temperatures for detecting temperature information such as the temperature of the purified gas purified by the particulate traps 4a and 4b. Sensors, 17a and 17b are heating units including electric heaters, burners, etc. arranged upstream of the filters in the particulate collection units 4a and 4b for heating and burning the particulates, and 18 is a heating unit 17a, A power supply unit composed of a battery or the like for supplying current / voltage to 17b, and 19 is an air supply valve 10a based on the differential pressure information detected by the differential pressure sensors 15a and 15b and the temperature information detected by the temperature sensors 16a and 16b. , 10
b, exhaust valves 11a, 11b, air supply valves 12a, 12
b, the air discharge valves 13a and 13b, the air supply unit 14, the control unit that controls the power supply unit 18, and the like, 20a and 20b are the power supply unit 1.
A heating unit switch for controlling on / off of the current / voltage supplied from 8 to the heating units 17a and 17b, and 21 is a power supply unit 1
8 is a control unit switch for controlling on / off of the current / voltage supplied from 8 to the control unit 19. Although not shown, the air supply valves 10a and 10b, the exhaust valves 11a and 11b, the air supply valves 12a and 12b, the air exhaust valves 13a and 13b, the air supply unit 14, the power supply unit 18, and the like and the control unit 19 are electrically connected. It is connected.

The operation of the conventional exhaust gas purifying apparatus for a diesel engine configured as described above will be described below. Here, the exhaust gas discharged from the diesel engine before the diesel engine is stopped is purified by the particulate trap portion 4a, and the air supply valve 10a and the discharge valve 11a are "opened". The air valve 10b and the discharge valve 11b are assumed to be "closed". First,
When the diesel engine starts operating, the exhaust gas discharged from the diesel engine is introduced into the particulate collecting section 4a through the exhaust pipe 1, the first air supply pipe 2 and the second air supply pipe 3a in order, and After the particulate matter contained in the exhaust gas is filtered by the first exhaust pipe 5a and the second exhaust pipe
Is sequentially discharged through the exhaust pipe 6 and the purified gas exhaust pipe 7 into the atmosphere. Next, the control unit 19 compares the differential pressure information detected by the differential pressure sensor 15a with the predetermined differential pressure information stored in advance (hereinafter referred to as combustion regeneration start information), and the differential pressure sensor 15
When the differential pressure information detected in a becomes equal to or higher than the combustion regeneration start information, it is determined that the particulate collection unit 4a has reached the combustion regeneration start time. Next, the control unit 19 introduces the exhaust gas into the particulate matter collecting unit 4b, and in order to burn and regenerate the particulate matter collecting unit 4a, the air feeding valve 1
0a and the exhaust valve 11a are output as "closed" signals, and the air supply valve 10b and the exhaust valve 11b are output as "open" signals. As a result, the air supply valve 10a and the exhaust valve 11a are "closed", the air supply valve 10b and the exhaust valve 11b are "open", and the exhaust gas is exhausted by the exhaust pipe 1, the first air supply pipe 2, and the second exhaust pipe. After the particulates introduced into the particulate trapping portion 4b through the trachea 3b are sequentially filtered and the particulates contained in the exhaust gas are filtered there, the first exhaust pipe 5b, the second exhaust pipe 6 and the purified gas exhaust gas are discharged. It is released into the atmosphere through the pipe 7 in sequence. Next, the control unit 19 outputs an "on" signal to the air supply unit 14 and the heating unit switch 20a, and outputs an "open" signal to the air supply valve 12a and the air discharge valve 13a. This allows
Air is supplied from the air supply unit 14 to the particulate collection unit 4a through the air supply pipe 8a, and the particulate matter accumulated on the filter of the particulate collection unit 4a is heated by the heating unit 17a for a predetermined heating time. Be heated. The air supplied to the particulate collecting portion 4a is discharged into the atmosphere through the air discharge pipe 9a. And the particulate is the ignition temperature (or combustion temperature)
And reaches the start of combustion. Here, the combustion gas in the combustion regeneration of the particulate matter trapping portion 4a uses the inflow velocity of the air introduced from the air supply portion 14 to the particulate matter trapping portion 4a to discharge the first exhaust pipe 5a and the air. It is released into the atmosphere through the pipe 9a in sequence. Next, the control unit 1
9 detects the elapse of a predetermined heating time and outputs an "OFF" signal to the heating unit switch 20a. Here, although the particulates stop heating (or combustion) by the heating unit 17a, they continue to be burned by the air from the air supply unit 14. Next, the control unit 19 compares the temperature information such as the temperature detected by the temperature sensor 16a with the predetermined temperature information stored in advance (hereinafter referred to as combustion regeneration end information), and the temperature detected by the temperature sensor 16a. When the information becomes equal to or lower than the combustion regeneration end information, the particulate collection unit 4a determines that the combustion regeneration end time has come. Next, the control unit 19
The "off" signal is output to the air supply unit 14, and the "close" signal is output to the air supply valve 12a and the air discharge valve 13a. As a result, the particulate collection unit 4a is set in a collection standby state. Next, the control unit 19 controls the differential pressure sensor 15
Comparing the differential pressure information detected in b with the combustion regeneration start information,
When the differential pressure information detected by the differential pressure sensor 15b becomes equal to or higher than the combustion regeneration start information, the particulate collection unit 4b determines that it is the combustion regeneration start time. Next, the control unit 1
Reference numeral 9 outputs a "closed" signal to the air supply valve 10b and the discharge valve 11b to introduce exhaust gas into the particulate collection unit 4a and burn and regenerate the particulate collection unit 4b, and to discharge the gas with the air supply valve 10a. It outputs an "open" signal to the valve 11a. After that, the control unit 19 repeats the above-described control, and while the diesel engine is in operation, the two particulate trapping units 4a and 4b alternately repeat purification of exhaust gas and combustion regeneration.

[0005]

However, in the above-mentioned conventional configuration, since the heating time of the heating part is set when the particulate collection part is burned and regenerated, the particulates are generated while the diesel engine is in operation. If the heating part is turned off while not igniting, the particulate collection part is not completely burned and regenerated, and even if the particulate is ignited, if the heating part is turned on, power is lost and the heating part is lost. However, there is a problem in that reliability is lacking. Further, when the diesel engine is stopped during combustion regeneration of the particulate collection part, if the combustion regeneration is interrupted midway, it will be difficult to ignite the particulates even if the combustion regeneration is attempted again when the diesel engine is restarted. When the particulate recovery unit is burned and regenerated, the diesel engine cannot be stopped until the combustion regeneration is completed.Therefore, the operator of the diesel engine must always pay attention to the combustion regeneration of the particulate collection unit. It had a problem of chipping. In addition, when the particulate trap is burned and regenerated, the particulate burns abnormally and the internal temperature of the particulate trap becomes high, causing the particulate trap to melt and crack, which is safe and reliable. It had a problem that it lacked. In addition, when the heating temperature is low when the particulate trap is regenerated by combustion, incomplete combustion of the particulates occurs, and the combustion regeneration time is lengthened, resulting in a lack of reliability. In addition, when combustion regeneration is started immediately after starting when starting the diesel engine, a considerable amount of electric power is required to raise the temperature to the ignition temperature of the particulates because the particulate collection part is cooled. There is a problem in that the curate trapping portion is subject to thermal stress (or thermal shock) due to a rapid temperature change, causing cracks, ruptures, and the like, which lacks reliability. In addition, since a series of control devices such as a heating unit and a sensor are required to purify the exhaust gas by the two particulate traps, it is inevitable that the device will become large and the cost will rise. Since the work becomes complicated, there is a problem in that the economy and productivity are lacking.

The present invention solves the above-mentioned problems of the prior art by reducing the thermal stress to the particulate trapping portion and burning the particulate trap portion with high efficiency and safety. An object of the present invention is to provide an exhaust gas purification device for a diesel engine, which is excellent in productivity.

[0007]

In order to achieve this object, an exhaust gas purifying apparatus for a diesel engine according to a first aspect of the present invention is connected to an end portion of an exhaust pipe of the diesel engine at a predetermined portion of a side wall. A first air supply pipe, a second air supply pipe that communicates with both ends of the first air supply pipe, and the second air supply pipe,
And a first discharge pipe that communicates with the end of the particulate collection unit, and both ends of the first discharge pipe that communicate with the end of the air supply pipe. A second exhaust pipe that communicates with the second exhaust pipe, and a purified gas exhaust pipe that communicates with a predetermined portion of the side wall of the second exhaust pipe,
An air supply pipe that communicates with a predetermined part of the side wall of the second air supply pipe, an air discharge pipe that communicates with a predetermined part of the side wall of the first discharge pipe, the first air supply pipe or the above. An air supply valve arranged at one end of the second air supply pipe or a portion in the vicinity thereof, or across the end parts of the first air supply pipe and the second air supply pipe, the first discharge pipe, or One end of the second discharge pipe or a portion in the vicinity thereof, or a discharge valve disposed across the ends of the first discharge pipe and the second discharge pipe, and the air supply pipe, respectively. An air supply valve provided, an air discharge valve provided in each of the air discharge pipes, an air supply unit for supplying air to the particulate collection unit via the air supply pipe, and the particulate collection unit. A heating part disposed in the collecting part, and an electric current applying a current / voltage to the heating part. Section, a differential pressure sensor for detecting differential pressure information indicating the differential pressure between the exhaust gas introduced into the particulate collection section and the purified gas purified by the particulate collection section, and the particulate collection Temperature sensor for detecting the temperature information indicating the temperature of the combustion gas discharged from the particulate collection part when the part is burned and regenerated, and the differential pressure information detected by the differential pressure sensor and the temperature sensor An exhaust gas purifying apparatus for a diesel engine, wherein the particulate trap collecting section alternately repeats purification and combustion regeneration of the exhaust gas. Concentration information indicating a carbon dioxide concentration detected by the carbon dioxide sensor when the control unit burns and regenerates the particulate trapping unit and a gas sensor, and Comparing the 憶 the predetermined density information was has a configuration having a combustion start determination unit that determines the start of combustion particulates of the particulate collection portion.

According to a second aspect of the present invention, there is provided an exhaust gas purifying apparatus for a diesel engine, wherein:
A concentration information comparison unit that compares the concentration information detected by the carbon dioxide sensor and the predetermined concentration information stored in advance when the particulate collection unit is burned and regenerated, and the result compared by the concentration information comparison unit. Based on the opening degree of the air supply valve and / or the air flow rate of the air supply section.

An exhaust gas purifying apparatus for a diesel engine according to a third aspect is the exhaust gas purifying apparatus according to the first or second aspect, further comprising another power source section for applying a current / voltage to the heating section, and the control section is a diesel engine. And a combustion regeneration continuation / stop determination unit that determines continuation / stop of combustion regeneration of the particulate collection unit based on the result of comparison by the concentration information comparison unit when stopping the operation of And a switching unit for applying a current / voltage to the heating unit by switching from the power source unit to the other power source unit when the particulate matter trapping unit continues combustion regeneration in the stop determination unit. have.

An exhaust gas purifying apparatus for a diesel engine according to a fourth aspect of the present invention is the exhaust gas purifying apparatus according to any one of the first to third aspects, in which both ends communicate with a predetermined portion of the side wall of the second air supply pipe. One communication pipe, a second communication pipe that communicates with a predetermined portion of the side wall of the first discharge pipe at both ends, and a predetermined portion of the side wall of the first communication pipe from the predetermined portion of the second communication pipe. A third communication pipe that communicates with a predetermined part of the side wall at both ends, one end of the first communication pipe or a portion in the vicinity thereof, or the first communication pipe and the second air supply pipe. A first circulation valve provided, and a second circulation valve disposed over one end of the second communication pipe or a portion in the vicinity thereof, or across the second communication pipe and the first discharge pipe. And the temperature information detected by the temperature sensor when the control unit burns and regenerates the particulate collection unit. If advance the stored circulating start determination unit for comparing the predetermined temperature information, on the basis of the result compared by circulating start determination unit of the first circulating valve and the second
And a circulation valve operating section for operating the circulation valve.

According to a fifth aspect of the present invention, there is provided an exhaust gas purifying apparatus for a diesel engine according to any one of the first to fourth aspects, wherein the air supply pipe and / or the air discharge pipe is the first communication pipe, The heating portion is communicated with a predetermined portion of the side wall of any one of the second communication pipe and the third communication pipe, and the heating unit is connected to the first communication pipe, the second communication pipe, or the third communication pipe. A configuration is provided in which any one of the pipes is provided, and an air supply unit is provided in at least one of the first communication pipe, the second communication pipe, and the third communication pipe. is doing.

Here, the carbon dioxide sensor is at least the downstream end of the particulate trap in order to detect concentration information indicating the concentration of carbon dioxide contained in the combustion gas discharged from the particulate trap. It is preferably arranged in any one of the section, the first exhaust pipe, and the air exhaust pipe. The concentration information stored in advance in the combustion start determination unit is higher than the concentration of carbon dioxide gas contained in the air supplied from the air supply unit, and the concentration of carbon dioxide gas in the combustion gas is 0.5 to 2
% Is preferred. That is, the combustion start determination unit determines that the combustion has started when the concentration information detected by the carbon dioxide sensor is 0.5 to 2% or more. The concentration information stored in advance in the concentration information comparison unit is such that the carbon dioxide concentration in the combustion gas is in the range of lower limit value 0.5% to upper limit value 10%, preferably in the range of lower limit value 2% to upper limit value 8%, Lower limit value is preferably 4%
~ It is preferable that the upper limit value is set to 6%. As the concentration of carbon dioxide gas in the combustion gas discharged from the particulate collection portion during combustion regeneration of the particulate collection portion becomes higher than the upper limit value of 6%, the thermal stress on the particulate collection portion increases and the particulate It becomes easier to cause melting loss / cracking etc. of the collecting part, and as the carbon dioxide concentration in the combustion gas becomes lower than the lower limit value of 4%, the burning rate and the burning efficiency of the particulates become low, and the cleaning of the particulate collecting part becomes difficult. Becomes insufficient,
Neither is preferable. The predetermined temperature information stored in advance in the circulation start determination unit is 0 ° C. or higher, preferably 100 ° C.,
More preferably, it is set to 200 ° C. As the predetermined temperature information, that is, the temperature of the particulate collection part that starts combustion regeneration becomes higher than 200 ° C, a tendency such as power loss appears, and the temperature of the particulate collection part that starts combustion regeneration becomes lower than 200 ° C. As a result, the thermal stress on the particulate collection part increases, and it becomes easy to cause meltdown / cracking of the particulate collection part. Moreover, the amount of electric power for heating the particulate collection part begins to increase. Not preferable. Examples of the air supply unit include a sirocco fan, an engine pump, a vane pump, and the like.

[0013]

With this configuration, a carbon dioxide gas sensor is provided in the system, and the concentration information indicating the carbon dioxide gas concentration detected by the carbon dioxide gas sensor when the control unit burns and regenerates the particulate trapping unit is stored in advance. By the configuration including a combustion start determination unit that determines the start of combustion of the particulates of the particulate collection unit by comparing predetermined concentration information, the inside of the particulate collection unit during combustion regeneration that could not be determined by the temperature sensor. Combustion start (or ignition or non-ignition) of the particulates can be detected, and the end of combustion of the particulates can also be detected, so that the particulates can be surely started to burn, and power loss and melting damage of the heating part are prevented. Therefore, combustion regeneration can be performed efficiently.

The concentration information comparing unit compares the concentration information detected by the carbon dioxide gas sensor with predetermined concentration information stored in advance when the control unit burns and regenerates the particulate collection unit, and the concentration information. A particulate collection unit at the time of combustion regeneration by a configuration including an adjustment unit that controls the opening degree of the air supply valve and / or the air flow rate of the air supply unit based on the result of comparison by the comparison unit. It is possible to prevent abnormal combustion and the like, and also to prevent incomplete combustion of the particulates, so that combustion efficiency is high and combustion regeneration can be performed safely.

The heating unit is provided with another power source unit for applying current / voltage, and the control unit is based on the result compared by the concentration information comparing unit when the operation of the diesel engine is stopped. Continuation of combustion regeneration in the collection unit /
A combustion regeneration continuation / stop determination unit that determines a stop, and when the combustion regeneration continuation / stop determination unit continues combustion regeneration of the particulate collection unit, the heating unit supplies the other power source to the heating unit. With a configuration that includes a switching unit that switches the parts to apply current / voltage, even if the diesel engine is stopped, it is possible to continue the combustion regeneration without interrupting the combustion regeneration and use the diesel engine. An operator who operates a car, etc., can freely start the car, etc. without being aware of the combustion and regeneration of the particulate collection unit.
It can be stopped and driving operability can be improved.

[0016] A first communication pipe that communicates at both ends with a predetermined portion of the side wall of the second air supply pipe, and a second communication that communicates at both ends with a predetermined portion of the side wall of the first discharge pipe. A pipe, a third communication pipe that communicates from a predetermined portion of the side wall of the first communication pipe to a predetermined portion of the side wall of the second communication pipe at both ends, and one end of the first communication pipe or A portion in the vicinity thereof, or a first circulation valve disposed across the ends of the first communication pipe and the second air supply pipe, and an end portion of the second communication pipe or a portion in the vicinity thereof, Or a second circulation valve disposed across the ends of the second communication pipe and the first discharge pipe,
In the circulation start determination unit, the control unit compares the temperature information detected by the temperature sensor with the predetermined temperature information stored in advance when the particulate collection unit is burned and regenerated, and the circulation start determination unit. With the configuration including the circulation valve operating unit that operates the first circulation valve and the second circulation valve based on the compared result, the particulate collection unit is burned and regenerated when the diesel engine is restarted. In this case, the particulate trap can be regenerated by burning it after heating it to a temperature near or above the burning start temperature of the particulate, so that thermal stress, etc. to the particulate trap can be suppressed, and cracks and ruptures can be prevented. As well as being able to save power and save electricity.

The air supply pipe and / or the air discharge pipe is communicated with a predetermined portion of a side wall of any one of the first communication pipe, the second communication pipe and the third communication pipe, and A heating unit is disposed in any one of the first communication pipe, the second communication pipe, or the third communication pipe, and at least the first communication pipe, the second communication pipe, or The third
Due to the configuration in which any one of the communication pipes of (1) and (2) is provided with the air supply section, when the particulate collection section is burned and regenerated when the diesel engine is restarted, the heating of the particulate collection section can be completed in a short time. It is possible to efficiently regenerate the combustion, and to simplify the system, reduce the weight, and save labor.

[0018]

【Example】

(Embodiment 1) Hereinafter, an exhaust gas purifying apparatus for a diesel engine according to a first embodiment of the present invention will be described with reference to the drawings. 1 is a schematic diagram showing a schematic configuration of an exhaust gas purifying apparatus for a diesel engine according to a first embodiment of the present invention, and FIG. 2 is a block diagram showing a schematic configuration of a control unit in FIG. 1 is an exhaust pipe, 2 is a first air supply pipe, 3a, 3
b is a second air supply pipe, 4a and 4b are particulate traps, 5a and 5b are first exhaust pipes, 6 is a second exhaust pipe,
7 is a purified gas exhaust pipe, 8a, 8b are air supply pipes, 9a,
9b is an air exhaust pipe, 10a, 10b are air supply valves, 11a,
11b is an exhaust valve, 13a and 13b are air exhaust valves, 15
a and 15b are differential pressure sensors, 16a and 16b are temperature sensors, 17a and 17b are heating parts, 18 is a power supply part, 20a,
Reference numeral 20b denotes a heating unit switch, which are the same as those in the conventional example and are designated by the same reference numerals and their description will be omitted. 1
2a 'and 12b' are air supply valves which are arranged in the air supply pipes 8a and 8b and whose opening degree is adjusted by a control unit 19 'which will be described later.
Reference numeral 4'denotes an air supply unit whose air flow rate is adjusted by the control unit 19 ', 19' indicates differential pressure information detected by the differential pressure sensors 15a and 15b, temperature information detected by the temperature sensors 16a and 16b, and carbon dioxide which will be described later. A control unit 19a for controlling the whole based on the concentration information detected by the gas sensors 22a and 22b.
Compares the concentration information detected by the carbon dioxide gas sensors 22a, 22b when the particulate collection units 4a, 4b are burned and regenerated with predetermined concentration information (hereinafter referred to as combustion start information) stored in advance to collect the particulates. Collecting parts 4a, 4
A combustion start determination unit that determines the start of combustion (or ignition, non-ignition) of the particulates deposited on the filter in b, 19b is a carbon dioxide gas sensor 22a, 22b when the particulate collection unit 4a, 4b is burned and regenerated. A density information comparison unit that compares the density information detected in step S with the predetermined density information (hereinafter referred to as predetermined upper limit value and lower limit value) stored in advance, 19c is based on the result compared by the density information comparison unit 19b. An adjusting unit that adjusts the opening of the air supply valves 12a 'and 12b' and the air flow rate of the air supply unit 14 ', and 19d is a combustion start determining unit 19a when the diesel engine stops operating.
The combustion regeneration continuation / stop determination unit for determining whether the combustion regeneration of the particulate collection units 4a, 4b is continued or stopped based on the result of the comparison, and 19e is the combustion regeneration continuation / stop determination unit 19d for the particulate collection unit. When the combustion regeneration of 4a, 4b is continued, the heating unit 17a, 17b is switched from the power supply unit 18 to another power supply unit 23 which will be described later and the current /
A switching unit for applying a voltage, 19f is a temperature sensor 16a, when the particulate collection units 4a, 4b are burned and regenerated.
A circulation start determination unit that compares the temperature information detected by 16b with predetermined temperature information (hereinafter, referred to as circulation start information) stored in advance, 19g is a later-described first based on the result compared by the circulation start determination unit 19f. Circulation valve operating section for operating the first circulation valve 28a, 28b and the second circulation valve 29a, 29b, 2
Reference numeral 1'is a changeover switch for switching between the power supply unit 18 for supplying current / voltage to the heating units 17a and 17b and the other power supply unit 23 based on the output signal from the control unit 19 'switching unit 19e.
2a and 22b are air discharge pipes 9 for detecting concentration information indicating the concentration of carbon dioxide gas contained in the combustion gas discharged from the particulate collection units 4a and 4b during combustion regeneration.
Carbon dioxide gas sensors disposed on a and 9b respectively, and 23 is another power supply unit composed of a backup battery or the like for supplying current / voltage to the heating units 17a and 17b, and 24a and 24.
b is a switch for a heating unit for on / off controlling the current / voltage supplied from the other power supply unit 23 to the heating units 17a, 17b, and 25 is a predetermined part on the side wall of the first discharge pipes 5a, 5b at both ends. The first communication pipe, which is communicated, 26 is the second air supply pipe 3
a second communication pipe communicated at both ends to a predetermined portion of the side walls of a and 3b, and 27 denotes a second portion from a predetermined portion of the side wall of the first communication pipe 25.
A third part connected at both ends to a predetermined part of the side wall of the communication pipe 26 of
Communication pipes, 28a, 28b are first circulation valves disposed near both ends of the first communication pipe 25, and 29a, 29b are second
2 is a second circulation valve disposed near both ends of the communication pipe 26 of FIG. Here, the combustion start determination unit 19a in the control unit,
Concentration information comparison unit 19b, adjustment unit 19c, combustion regeneration continuation /
Stop determination unit 19d, switching unit 19e, circulation start determination unit 19
f and the circulation valve operating portion 19g will be described with reference to the drawings. FIG. 3A shows the combustion regeneration time of the particulate collection portion and the combustion discharged from the particulate collection portion when the flow rate of the air from the air supply portion is constant when the particulate collection portion is burned and regenerated. It is a characteristic view which shows the relationship with the density | concentration of the carbon dioxide gas contained in gas. As shown in FIG. 3A, the concentration of carbon dioxide gas in the combustion gas discharged from the particulate collection portion during the combustion regeneration of the particulate collection portion is as shown in FIG. (Including exhaust gas trapped in the second air supply pipe, the particulate trap and the first exhaust pipe by the "closed" air supply valve and exhaust valve)
The carbon dioxide concentration in the atmosphere is shown, and about 5 minutes after the start of combustion regeneration, the carbon dioxide concentration rapidly increases after the particulate ignition shown by the arrow A in FIG.
After a lapse of minutes, the combustion peak period shown in the approximate center of FIG. 3 (a) is reached, and then gradually decreases, and about 20 minutes after the start of the combustion regeneration, the view of arrow B in FIG. It will be constant. In the present embodiment, when burning the particulate trap portion, the combustion start determination portion 19a compares the concentration information detected by the carbon dioxide gas sensors 22a and 22b with the combustion start information and detects the carbon dioxide gas sensors 22a and 22b. When the concentration information becomes equal to or higher than the combustion start information, it is determined that the particulate matter has started combustion, and an "OFF" signal is output to the heating unit switches 20a and 20b. When burning the particulate traps 4a and 4b, the concentration information comparison unit 19b compares the concentration information detected by the carbon dioxide gas sensors 22a and 22b with predetermined upper and lower limits, and the carbon dioxide gas sensors 22a and 22b. If the density information detected in 22b is not within the range of the predetermined upper limit value and lower limit value, the adjusting unit 1
9c adjusts the opening of the air supply valves 12a ', 12b' and the air flow rate of the air supply unit 14 'in order to keep the carbon dioxide concentration in the combustion gas discharged from the particulate traps 4a, 4b within a predetermined range. To control. In this example, the upper limit value was 6% and the lower limit value was 4%. This is shown in FIG. FIG. 3B is a combustion regeneration of the particulate trap portion when the opening degree of the air supply valve and / or the air flow rate from the air supply portion is adjusted (or controlled) when the particulate trap portion is burned and regenerated. FIG. 6 is a characteristic diagram showing a relationship between time and the concentration of carbon dioxide gas contained in the combustion gas discharged from the particulate matter collecting section. Further, when the diesel engine stops the operation, the switching unit 19e outputs a switching signal to the switching switch 21 'to heat the combustion regeneration continuation / stop determination unit 19d based on the result of comparison by the combustion start determination unit 19a. A current / voltage is applied to the parts 17a and 17b from another power supply part 23 to collect the particulate matter collecting part 4
The combustion regeneration of a and 4b is continued. Further, when starting the combustion regeneration of the particulate trapping units 4a, 4b, the circulation start determination unit 19f causes the temperature sensors 16a, 1b.
The temperature information detected by 6b is compared with the circulation start information, and if the temperature information detected by the temperature sensors 16a, 16b is equal to or lower than the circulation start information, the circulation valve operating unit 19g determines that the first circulation valves 28a, 28b. By operating the second circulation valves 29a, 29b, the purified gas purified by one of the particulate collection parts 4a, 4b is supplied to the other particulate collection part 4 of the other part.
b, 4a. Although not shown, the air supply valves 10a and 10b, the discharge valves 11a and 11b, the air supply valves 12a 'and 12b', the air discharge valves 13a and 13b, the air supply unit 14 ', the differential pressure sensors 15a and 15b, and the temperature sensor. 16a, 16b, power supply unit 18, carbon dioxide sensor 22
It is assumed that a, 22b, the first circulation valves 28a, 28b, the second circulation valves 29a, 29b and the control unit 19 'are electrically connected.

The operation of the exhaust gas purifying apparatus for a diesel engine constructed as described above will be described below.
FIG. 4 is a flowchart of the exhaust gas purifying apparatus for a diesel engine according to the first embodiment of the present invention. Here, the exhaust gas discharged from the diesel engine before the operation of the diesel engine is further purified by the one particulate collecting portion 4a, and the air supply valve 10a and the discharge valve 1
1a is "opened", and an air supply valve 10b, an exhaust valve 11b, air supply valves 12a ', 12b', and air exhaust valves 13a, 13
b, the first circulation valves 28a and 28b, and the second circulation valve 29.
It is assumed that a and 29b are "closed". In addition, it is assumed that combustion regeneration has not been started in the other particulate collection unit 4b before the operation of the diesel engine is stopped.

First, when the operation of the diesel engine is started (S1), the exhaust gas discharged from the diesel engine is cleaned by the particulate collecting portion 4a on one side, so that the exhaust pipe 1, the first air pipe 2, After the particulates introduced into the particulate collecting portion 4a through the second air supply pipe 3a are sequentially filtered and the particulates contained in the exhaust gas are filtered, the first exhaust pipe 5a and the second exhaust pipe 6 are provided. , Through the purified gas exhaust pipe 7 to the atmosphere (S2). Next, the control unit 19 'confirms whether the other particulate collection unit 4b is in a collection standby state, that is, whether combustion regeneration is necessary (S3). Where No
If it is, that is, if the other part of the particulate collection unit 4b is being burnt and regenerated before the operation of the diesel engine is stopped and the process is interrupted midway, the process jumps to S6. If Yes, that is, the particulate If the collection unit 4b is in the collection standby state and combustion regeneration is not required, the process jumps to S4. Here, since the particulate collection unit 4b is in a collection standby state, S4
Shall jump to. Next, the control unit 19 'compares the differential pressure information detected by the differential pressure sensor 15a with the combustion regeneration start information, and determines whether or not the combustion regeneration of the particulate trapping unit 4a should be started (S4). Where No
If the differential pressure information detected by the differential pressure sensor 15a is equal to or lower than the combustion regeneration start information, S4 is again performed.
If Yes, that is, if several hours have passed from the start of operation of the diesel engine, the particulates are accumulated in the particulate collection part 4a to some extent, and the differential pressure information detected by the differential pressure sensor 15a is burned. If the reproduction start information is exceeded, the process jumps to S5. next,
The control unit 19 'determines that the particulate collection unit 4a has reached the combustion regeneration start time, introduces the exhaust gas into the other particulate collection unit 4b, and burns and regenerates the particulate collection unit 4a. Outputs a "closed" signal to the air supply valve 10a and the discharge valve 11a, and
An "open" signal is output to 0b and the discharge valve 11b (S5).
As a result, the air supply valve 10a and the exhaust valve 11a are "closed", the air supply valve 10b and the exhaust valve 11b are "open", and the exhaust gas is exhausted by the exhaust pipe 1, the first air supply pipe 2, and the second exhaust pipe. After the particulates introduced into the particulate trapping portion 4b through the trachea 3b are sequentially filtered and the particulates contained in the exhaust gas are filtered there, the first exhaust pipe 5b, the second exhaust pipe 6 and the purified gas exhaust gas are discharged. It is released into the atmosphere through the pipe 7 in sequence (S2).
Next, the control unit 19 'confirms whether the other particulate collection unit 4a needs combustion regeneration (S).
3). Here, the control unit 19 'judges the combustion regeneration of the particulate collection unit 4a and jumps to S6. Next, the circulation start determination unit 19f of the control unit 19 'confirms whether or not the particulate collection unit 4a has an appropriate temperature for performing combustion regeneration (S6). Here, if No, that is, if the particulate trap portion 4a has not been warmed up (or heated) at a predetermined temperature or higher as immediately after the start of operation of the diesel engine, the process jumps to S8 and Y
If it is es, that is, if several hours have passed from the start of operation of the diesel engine and the particulate trapping unit 4a has been sufficiently warmed up to a predetermined temperature or higher, the routine jumps to S7. Here, it is assumed that the diesel engine has jumped to S7 because it has been sufficiently heated to a predetermined temperature or more after several hours have passed since the start of operation. Next, the control unit 19 '
Outputs an "ON" signal to the air supply unit 14 'and the heating unit switch 20a, and outputs an "Open" signal to the air supply valve 12a and the air discharge valve 13a (S7). As a result, air is supplied from the air supply unit 14 'to the particulate collection unit 4a via the air supply pipe 8a, and the particulate matter deposited on the filter of the particulate collection unit 4a is heated by the heating unit 17a. . The air supplied to the particulate collecting portion 4a is discharged into the atmosphere through the air discharge pipe 9a. Next, the control unit 19 '
The combustion start determination unit 19a of the
It is confirmed whether or not the particulate in a has been ignited (S9). Here, if No, the process jumps to S9 again, and if Yes, that is, the particulate in the particulate collecting unit 4a is heated by the heating unit 17.
If it is heated by a and reaches the ignition temperature and combustion is started, the routine jumps to S10. Here, the combustion gas at the time of combustion regeneration of the particulate trapping portion 4a uses the inflow velocity of the air introduced into the particulate trapping portion 4a from the air supply portion 14 'to pass through the air exhaust pipe 9a to the atmosphere. It is released inside. Next, the control section 19 'outputs an "OFF" signal to the heating section switch 20a (S10). Here, although the particulates stop heating (or combustion) by the heating unit 17a, they continue to be burned by the air from the air supply unit 14 '. Next, the control unit 19 'determines whether or not the combustion regeneration of the particulate collection unit 4a is completed (S11). Here, if No,
That is, if the temperature information detected by the temperature sensor 16a is equal to or higher than the combustion regeneration end information, the process jumps to S12, Yes.
If the temperature information detected by the temperature sensor 16a is equal to or lower than the combustion regeneration end information, the process jumps to S14. Here, it is assumed that the temperature information detected by the temperature sensor 16a is equal to or higher than the combustion regeneration end information, that is, the combustion regeneration of the particulate trapping portion 4a is not completed, and therefore the routine jumps to S12. Next, the concentration information comparison unit 19b of the control unit 19 'confirms whether the concentration of carbon dioxide in the combustion gas discharged from the particulate collection unit 4a is within a predetermined range (S12). Here, if Yes, the process jumps to S11 again, and No.
If so, jump to S13. Here, it is assumed that the concentration information detected by the carbon dioxide sensor 22a is outside the predetermined range, and therefore the process jumps to S13. next,
The control unit 19 'of the control unit 19' controls the opening of the air supply valve 12a 'and the air supply unit 14' to keep the carbon dioxide concentration in the combustion gas discharged from the particulate trapping unit 4a within a predetermined range. The air supply amount supplied from is adjusted (S13), and the process again jumps to S12. Next, S12
~ S13 is repeated and the particulate collection unit 4a
When the combustion regeneration of the air is completed, the control unit 19 'outputs an "OFF" signal to the air supply unit 14' and the air supply valve 1
A "close" signal is output to 2'a and the air exhaust valve 13a (S
14). As a result, the particulate collection unit 4a is set in a collection standby state. Further, in S6 described above, No
If the above is true, that is, immediately after the diesel engine is started, the particulate collection unit 4 that performs combustion regeneration
If the temperature of a has fallen, it jumps to S8. Next, the circulation valve operating unit 19g of the control unit 19 'outputs an "open" signal to the first circulation valve 28a and the second circulation valve 29a (S8). As a result, the particulate collection unit 4b
The purified gas purified in (1) is introduced into the particulate collection unit 4a through the first communication pipe 25, the third communication pipe 27, and the second communication pipe 26 in this order, and the particulate collection unit 4a introduces the purified gas. 15 in about 10 minutes depending on the exhaust gas generated
It is heated to about 0 ° C. Further, when the control unit 19 'detects that the diesel engine is stopped in S10 to S13, the combustion regeneration continuation / stop determination unit 19d causes the particulate collection units 4a, 4b to burn based on the result of comparison by the concentration information comparison unit 19b. It is judged whether the regeneration is continued or stopped, and when the particulates of the particulate collection units 4a and 4b are started to burn, the combustion regeneration continuation / stop determination unit 19d.
Continues the combustion regeneration of the particulate traps 4a and 4b, and the changeover unit 19e outputs a changeover signal to the changeover switch 21 'to switch the heating units 17a and 17b from the power supply unit 18 to the other power supply unit 23 so that the current flows. / Apply voltage.

As described above, according to this embodiment, the carbon dioxide gas sensor in the system, the other power supply unit for applying the current / voltage to the heating unit, and the both ends of the predetermined portion of the side wall of the second air supply pipe. A first communication pipe that communicates with the second communication pipe, both ends of which communicate with a predetermined portion of the side wall of the first discharge pipe, and a second communication pipe from a predetermined portion of the side wall of the first communication pipe. A third communication pipe that communicates at both ends with a predetermined part of the side wall of the first communication valve, a first circulation valve disposed near both ends of the first communication pipe, and near both ends of the second communication pipe. A second circulation valve provided, and the control unit stores concentration information indicating a carbon dioxide concentration detected by the carbon dioxide sensor when the particulate trap is burned and regenerated, and a predetermined concentration stored in advance. A combustion start determination unit that compares information to determine the start of combustion of the particulates in the particulate collection unit; A concentration information comparison unit that compares the concentration information detected by the acid gas sensor with predetermined concentration information stored in advance, and the opening of the air supply valve and / or the air supply unit based on the result of the comparison made by the concentration information comparison unit. The control unit that controls the air flow rate of the diesel engine and the combustion regeneration continuation / judgment that determines whether the particulate trapping unit continues / stops combustion regeneration based on the result of comparison by the concentration information comparison unit when the operation of the diesel engine is stopped. When the combustion recovery of the particulate trapping part is continued by the stop determination part and the combustion recovery continuation / stop determination part, the heating part is switched from the power supply part to another power supply part to supply current / current.
Since a switching unit that applies voltage is provided, the heating unit is turned off when the start of burning of the particulates in the particulate collection unit that is burned and regenerated is detected, so that it is possible to reliably start the burning of particulates and loss of power. It is possible to prevent melting damage of the heating part, prevent abnormal combustion of the particulate collection part at the time of combustion regeneration, and perform combustion regeneration efficiently and safely. An operator who operates a car or the like can freely start / stop the car or the like without paying attention to the combustion regeneration of the particulate collect part, and when the diesel engine is restarted, the party collect part After heating to near the ignition temperature of the curate, the particulate collection part is burned and regenerated, so the particulate collection part is heated. Thermal shock can be suppressed to time, it is possible to prevent occurrence of cracks or ruptures due thermal stress and the like.

(Second Embodiment) An exhaust gas purifying apparatus for a diesel engine according to a second embodiment of the present invention will be described below with reference to the drawings. FIG. 5 is a schematic diagram showing a schematic configuration of an exhaust gas purifying apparatus for a diesel engine according to a second embodiment of the present invention. 1 is an exhaust pipe, 2 is a first air supply pipe, 3a and 3b are second air supply pipes, 4a and 4b are particulate traps, 5a and 5b are first exhaust pipes, and 6 is a second exhaust pipe. , 7 is a purified gas exhaust pipe, 10a and 10b are air supply valves, 11a and 11b are exhaust valves, 14 'is an air supply unit,
Reference numerals 15a and 15b are differential pressure sensors, 16a and 16b are temperature sensors, 18 is a power supply unit, 19 'is a control unit, 21' is a changeover switch, 23 is another power supply unit, 25 is a first communicating pipe, 26
Is a second communication pipe, 27 is a third communication pipe, 28a, 28b
Is the first circulation valve, and 29a and 29b are the second circulation valves, which are the same as those in the first embodiment, and are denoted by the same reference numerals and the description thereof will be omitted. The difference from the first embodiment is that the air supply pipes 8 ′ are respectively provided at predetermined portions of the side wall of the third communication pipe 27.
And the air discharge pipe 9'communicate with each other, and the heating portion 17 'is provided in the third communication pipe 27, so that the air supply valve 12 ",
An air exhaust valve 13 ', a carbon dioxide sensor 22', and heating unit switches 20 'and 24' are provided one by one, and an air supply unit 30 made of a sirocco fan or the like is provided in the middle of the third communication pipe 27. It is the point where it is arranged.

The operation of the exhaust gas purifying apparatus for a diesel engine in this embodiment is the same as that of the first embodiment except that the control unit 19 'drives the air supply unit 30 in S8 of FIG.

As described above, according to this embodiment, the air supply pipe and the air discharge pipe are communicated with the predetermined portion of the side wall of the third communication pipe, and the heating portion and the air supply are provided in the third communication pipe. Since the parts are installed, warming up / preheating of the particulate collection part when restarting the diesel engine can be completed in a short time, efficient combustion regeneration can be achieved, and system simplification, cost reduction, and labor saving can be achieved. In addition, the weight of the system can be reduced. In the conventional exhaust gas purifying device for a diesel engine, a power amount of 0.4 kWh was required, whereas in the present embodiment, a power amount of 0.3 kWh was able to be saved.

[0025]

As described above, in the exhaust gas purifying apparatus for a diesel engine of the present invention, the first air feeding pipe communicating with the end portion of the exhaust pipe of the diesel engine at a predetermined portion of the side wall and the first air feeding pipe. A second air supply pipe which is communicated with both ends of the trachea,
Particulate traps that communicate with the ends of the second air supply pipes, first exhaust pipes that communicate with the ends of the particulate traps, and ends of the first exhaust pipes. A second exhaust pipe that communicates with both ends of the second exhaust pipe, a purified gas exhaust pipe that communicates with a predetermined portion of the side wall of the second exhaust pipe, and a predetermined portion of the side wall of the second air supply pipe that communicates with each other. An air supply pipe, an air discharge pipe communicating with a predetermined portion of the side wall of the first discharge pipe, one end of the first air supply pipe or the second air supply pipe, or a portion in the vicinity thereof, or An air supply valve disposed across the ends of the first air supply pipe and the second air supply pipe, one end of the first exhaust pipe or the second exhaust pipe, or a portion in the vicinity thereof, Or a discharge valve disposed across the ends of the first discharge pipe and the second discharge pipe; Air supply valves respectively arranged in the air supply pipes, air discharge valves respectively arranged in the air discharge pipes, and an air supply unit for supplying air to the particulate collection unit via the air supply pipes. A heating unit arranged in the particulate collection unit; a power supply unit for applying current / voltage to the heating unit; exhaust gas introduced into the particulate collection unit and the particulate collection unit. A differential pressure sensor for detecting differential pressure information indicating the differential pressure of the purified gas purified by the method, and the temperature of the combustion gas discharged from the particulate trap when the particulate trap is regenerated by combustion. A temperature sensor that detects temperature information indicating, and a control unit that controls the whole by the differential pressure information detected by the differential pressure sensor and the temperature information detected by the temperature sensor, and An exhaust gas purifying apparatus for a diesel engine that alternately repeats purification and combustion regeneration of exhaust gas in a particulate trap, wherein a carbon dioxide sensor is provided in the system, and the controller burns and regenerates the particulate trap. At this time, a combustion start determination unit is provided to determine the combustion start of the particulates in the particulate collection unit by comparing the concentration information indicating the carbon dioxide concentration detected by the carbon dioxide sensor with the predetermined concentration information stored in advance. Therefore, it is possible to detect the start of combustion (or ignition or non-ignition) of the particulates in the particulate collection part during combustion regeneration that could not be judged by the temperature sensor, and it is also possible to detect the end of combustion of the particulates.
It is possible to provide a diesel engine exhaust gas purifying device that can start combustion reliably without loss of electric power or melting of a heating unit, can efficiently perform combustion regeneration, and is excellent in reliability and safety.

Further, the control unit compares the concentration information detected by the carbon dioxide gas sensor with the predetermined concentration information stored in advance when the particulate collection unit is burned and regenerated, and the concentration information comparing unit. Since the control unit adjusts the opening degree of the air supply valve and / or the air flow rate of the air supply unit based on the result compared by the information comparison unit, the particulate collection unit at the time of combustion regeneration. It is possible to prevent abnormal combustion of particles and incomplete combustion of particulates.
It is possible to provide an exhaust gas purification device for a diesel engine that can perform combustion regeneration with high safety and combustion efficiency and that is highly reliable and safe.

Further, the heating section is provided with another power source section for applying a current / voltage, and the control section is based on the result compared by the concentration information comparing section when the operation of the diesel engine is stopped. A combustion regeneration continuation / stop determination unit that determines continuation / stop of combustion regeneration of the curate collection unit, and a heating unit when the combustion regeneration continuation / stop determination unit continues combustion regeneration of the party curate collection unit On the other hand, a switching unit that switches from the power source unit to the other power source unit and applies current / voltage is provided, so that even if the diesel engine is stopped, the combustion regeneration is continuously continued without interruption. The operator, who operates a vehicle using a diesel engine, can freely start / stop the vehicle, etc., without being aware of combustion regeneration of the particulate collection unit. It is possible to improve the operability can be provided an exhaust gas purifying apparatus for reliability and driving operation excellent in the diesel engine.

Further, a first communicating pipe communicating at both ends with a predetermined portion of the side wall of the second air supply pipe and a second communicating pipe having both ends with a predetermined portion of the side wall of the first discharge pipe. A communication pipe, a third communication pipe that communicates from a predetermined portion of the side wall of the first communication pipe to a predetermined portion of the side wall of the second communication pipe at both ends, and one end of the first communication pipe. Or a portion in the vicinity thereof, or a first circulation valve disposed across the end portions of the first communication pipe and the second air supply pipe, and one end portion of the second communication pipe or a portion in the vicinity thereof Or a second circulation valve disposed across the ends of the second communication pipe and the first discharge pipe, the control unit burning and regenerating the particulate trapping unit. And a circulation start determination unit that compares the temperature information detected by the temperature sensor with predetermined temperature information stored in advance, and the circulation opening determination unit. Since the circulation valve operation unit that operates the first circulation valve and the second circulation valve based on the result compared by the determination unit, the particulate collection unit is burned when the diesel engine is restarted. When regenerating, the particulate collection part is heated and heated sufficiently near or above the combustion start temperature of the particulates, and then regenerated by combustion, so that thermal stress, etc. to the particulate collection part can be suppressed, and cracks and ruptures can be prevented. It is possible to provide an exhaust gas purifying device for a diesel engine, which can be prevented, can save power and can save power, and is excellent in economical efficiency and driving operability.

Further, the air supply pipe and / or the air discharge pipe is communicated with a predetermined portion of a side wall of any one of the first communication pipe, the second communication pipe or the third communication pipe,
The heating unit is disposed in any one of the first communication pipe, the second communication pipe, and the third communication pipe, and at least the first communication pipe and the second communication pipe. Or, since the air supply unit is provided in any one of the third communication pipes,
When the particulate collection part is burned and regenerated when the diesel engine is restarted, the heating of the particulate collection part can be completed in a short time, efficient combustion and regeneration can be achieved, and the system can be simplified, lightweight, and labor-saving. Therefore, it is possible to provide an exhaust gas purification device for a diesel engine, which is excellent in productivity, economy, and reliability.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a schematic configuration of an exhaust gas purifying apparatus for a diesel engine according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a schematic configuration of a control unit in FIG.

FIG. 3 (a): Combustion regeneration time of the particulate collection unit and discharge from the particulate collection unit when the air flow rate from the air supply unit is constant when the particulate collection unit is burned and regenerated. Characteristic diagram showing the relationship with the concentration of carbon dioxide gas contained in the combustion gas. (B) Adjusting the opening of the air supply valve and / or the air flow rate from the air supply part when the particulate collection part is regenerated by combustion. A characteristic diagram showing the relationship between the combustion regeneration time of the particulate matter collecting section when (or controlled) and the concentration of carbon dioxide gas contained in the combustion gas discharged from the particulate matter collecting section.

FIG. 4 is a flowchart of an exhaust gas purifying apparatus for a diesel engine according to the first embodiment of the present invention.

FIG. 5 is a schematic diagram showing a schematic configuration of an exhaust gas purifying apparatus for a diesel engine according to a second embodiment of the present invention.

FIG. 6 is a schematic diagram showing a schematic configuration of a conventional diesel engine exhaust gas purification device.

[Explanation of symbols]

1 Exhaust Pipe 2 First Air Pipe 3a, 3b Second Air Pipe 4a, 4b Particulate Collection 5a, 5b First Exhaust Pipe 6 Second Exhaust Pipe 7 Purified Gas Exhaust Pipe 8a, 8b, 8 ' Air supply pipe 9a, 9b, 9'Air discharge pipe 10a, 10b Air supply valve 11a, 11b Discharge valve 12a, 12b, 12a ', 12b', 12 "Air supply valve 13a, 13b, 13a 'Air discharge valve 14, 14 ′ Air supply part 15a, 15b Differential pressure sensor 16a, 16b Temperature sensor 17a, 17b, 17 ′ Heating part 18 Power supply part 19, 19 ′ Control part 19a Combustion start determination part 19b Concentration information comparison part 19c Control part 19d Combustion regeneration continuation / Stop determination unit 19e Switching unit 19f Circulation start determination unit 19g Circulation valve operation unit 20a, 20b, 20 ', 24a, 24b, 24' Heating unit switch 2 Control unit switch 21 'Changeover switch 22a, 22b, 22' Carbon dioxide sensor 23 Other power supply unit 25 First communication pipe 26 Second communication pipe 27 Third communication pipe 28a, 28b First circulation valve 29a, 29b Second circulation valve 30 Air supply unit

Claims (5)

[Claims] 1. A first air supply pipe communicating with an end of an exhaust pipe of a diesel engine at a predetermined portion of a side wall, and a second air supply pipe communicating with both ends of the first air supply pipe, respectively. The second
And a first discharge pipe that communicates with the end of the particulate collection unit, and both ends of the first discharge pipe that communicate with the end of the air supply pipe. A second exhaust pipe that communicates with the second exhaust pipe, and a purified gas exhaust pipe that communicates with a predetermined portion of the side wall of the second exhaust pipe,
An air supply pipe that communicates with a predetermined part of the side wall of the second air supply pipe, an air discharge pipe that communicates with a predetermined part of the side wall of the first discharge pipe, the first air supply pipe or the above. An air supply valve arranged at one end of the second air supply pipe or a portion in the vicinity thereof, or across the end parts of the first air supply pipe and the second air supply pipe, the first discharge pipe, or One end of the second discharge pipe or a portion in the vicinity thereof, or a discharge valve disposed across the ends of the first discharge pipe and the second discharge pipe, and the air supply pipe, respectively. An air supply valve provided, an air discharge valve provided in each of the air discharge pipes, an air supply unit for supplying air to the particulate collection unit via the air supply pipe, and the particulate collection unit. A heating part disposed in the collecting part, and an electric current applying a current / voltage to the heating part. Section, a differential pressure sensor for detecting differential pressure information indicating the differential pressure between the exhaust gas introduced into the particulate collection section and the purified gas purified by the particulate collection section, and the particulate collection Temperature sensor for detecting the temperature information indicating the temperature of the combustion gas discharged from the particulate collection part when the part is burned and regenerated, and the differential pressure information detected by the differential pressure sensor and the temperature sensor An exhaust gas purifying apparatus for a diesel engine, wherein the particulate trap collecting section alternately repeats purification and combustion regeneration of the exhaust gas. A gas sensor is provided, and when the control unit burns and regenerates the particulate trapping unit, concentration information indicating the concentration of carbon dioxide gas detected by the carbon dioxide gas sensor and the like, and a preliminary information. Exhaust gas purifying device for a diesel engine by comparing the stored predetermined density information has been characterized by comprising a combustion start determination unit that determines the start of combustion particulates of the particulate collection portion. 2. A concentration information comparison unit, wherein the control unit compares the concentration information detected by the carbon dioxide gas sensor with a predetermined concentration information stored in advance when the particulate collection unit is burned and regenerated, and The exhaust gas of a diesel engine according to claim 1, further comprising: an adjusting unit that adjusts an opening degree of the air supply valve and / or an air flow rate of the air supply unit based on a result of comparison by the concentration information comparing unit. Purification device. 3. The heating unit further comprises another power supply unit for applying a current / voltage, wherein the control unit is based on a result compared by the concentration information comparison unit when the operation of the diesel engine is stopped. Continuation of combustion regeneration of the particulate collection unit /
A combustion regeneration continuation / stop determination unit that determines a stop, and when the combustion regeneration continuation / stop determination unit continues combustion regeneration of the particulate collection unit, the heating unit supplies the other power source to the heating unit. An exhaust gas purifying apparatus for a diesel engine according to claim 1 or 2, further comprising: a switching unit that switches the unit to apply a current / voltage. 4. A first communication pipe communicating at both ends with a predetermined portion of a side wall of the second air supply pipe, and a second communication pipe having both ends communicating with a predetermined portion of a side wall of the first discharge pipe. Communication pipe, a third communication pipe communicated from a predetermined portion of the side wall of the first communication pipe to a predetermined portion of the side wall of the second communication pipe at both ends, and one end of the first communication pipe. Part or a portion in the vicinity thereof, or a first circulation valve disposed over the first communication pipe and the second air supply pipe, and one end of the second communication pipe or a portion in the vicinity thereof,
Alternatively, the second communication pipe and a second circulation valve disposed across the first discharge pipe may be provided, and the temperature may be adjusted when the control unit burns and regenerates the particulate trapping unit. A circulation start determination unit for comparing the temperature information detected by the sensor with predetermined temperature information stored in advance, and the first circulation valve and the second circulation based on the result of comparison by the circulation start determination unit. An exhaust gas purifying apparatus for a diesel engine according to any one of claims 1 to 3, further comprising: a circulation valve operating section that operates a valve. 5. The air supply pipe and / or the air discharge pipe is communicated with a predetermined portion of a side wall of any one of the first communication pipe, the second communication pipe and the third communication pipe. The heating unit is disposed in any one of the first communication pipe, the second communication pipe, and the third communication pipe, and at least the first communication pipe and the second communication pipe. Tube or the third
The exhaust gas purifying apparatus for a diesel engine according to any one of claims 1 to 4, wherein an air supply unit is provided in any one of the communication pipes.