JPH08128314A - Filter regeneration device - Google Patents

Abstract

PURPOSE: To obtain a filter regeneration device for an internal combustion engine for optimally operating a heating means and a combustion improving gas supplying means by detecting starting or completion of combustion of particulates in exhaust gas of a diesel engine or the like. CONSTITUTION: A particulate combustion judgment means 33 determines starting and completion of combustion of particulates during regeneration of a filter 4 based on detection values of a microwave electromagnetic field intensity sensing means 17 or a pressure detection sensing means 28.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention collects particulates (particulate matter) contained in exhaust gas discharged from a diesel engine by a filter and heats and burns the particulates collected by the filter. The present invention relates to a filter regeneration device that removes and regenerates the collection performance of a filter.

[0002]

2. Description of the Related Art A filter regeneration state, that is, a particulate combustion state, includes a filter temperature before starting regeneration, particulate collection weight, particulate quality, particulate heating energy, and a combustion gas for promoting combustion of particulates. It is deeply dependent on the supply flow rate and temperature, the unburned state during the previous filter regeneration (regeneration may be stopped during particulate combustion and then regenerated). Therefore, if the filter regeneration is performed by a single regeneration sequence, the particulates may not burn properly or the burning temperature may become excessively high, and the durability of the filter may be impaired. Therefore, it is necessary to detect various states with a sensor and perform reproduction control according to the detected states.

Above all, it is desirable to be able to detect the start or end of the combustion of particulates. Here, the auxiliary combustion gas for particulate combustion is supplied to burn the particulates, but insufficient heating (preheating) until the auxiliary combustion gas is supplied results in particulate combustion failure, and excessive preheating causes excessive combustion temperature. In particular, the temperature gradient becomes steeper at the initial stage of particulate combustion. Any of these will greatly impair the durability of the filter. On the other hand, it is necessary to suppress the power consumption during filter regeneration considering the on-vehicle power capacity, and in the case of a single filter, it is necessary to bypass the exhaust gas while avoiding the regeneration filter during filter regeneration.
It is necessary to shorten the regeneration time in consideration of the fact that unpurified exhaust gas is discharged. Therefore, it is desirable to stop the operation of the heating means immediately after the particulates are burned, supply a large amount of air to the filter to cool the filter, and finish the filter regeneration. However, even if the particulate combustion is not completed, increasing the amount of the auxiliary combustion gas for cooling the filter causes rapid combustion and raises the combustion temperature.

From the background described above, various combustion start / end detection systems have been proposed.

In Japanese Utility Model Laid-Open No. 62-122110, the light emission state of the filter is detected by an optical sensor to identify the particulate combustion.

Further, Japanese Patent Laid-Open No. 59-18220 detects the temperature of the exhaust gas leaving the filter during regeneration, and stops heating when the rising gradient of this temperature is above a predetermined value. Further, in Japanese Patent Laid-Open No. 59-20515, the regeneration is similarly ended when the exhaust gas temperature during the regeneration of the filter becomes equal to or lower than a predetermined value. These are a kind of combustion start or combustion end detection method using the auxiliary combustion gas temperature after passing through the filter.

Further, in Japanese Unexamined Patent Publication (Kokai) No. 5-179931, the preheating time is shortened as the filter temperature becomes higher immediately before the start of regeneration. This is to calculate the time to reach the particulate combustion start temperature from the filter temperature before filter regeneration, instead of detecting the particulate combustion start.

[0008]

The above-mentioned particulate combustion start or end detection has the following problems.

First, in the method of identifying the light emission state of the filter by an optical sensor, the sensor or the optical system uses exhaust gas during operation of the internal combustion engine (up to about 500 ° C.) and exhaust gas after passing through the filter during filter regeneration (up to 500). There is a problem in durability of the sensor or optical system due to exposure to radiant heat from the filter during filter regeneration.

In the case of utilizing the exhaust gas temperature during regeneration, the combustion state of a part of the particulates deposited on the filter is affected by the heat capacity of the auxiliary gas itself, the temperature detecting means, the filter, or the auxiliary gas flow path. It is difficult to detect with high accuracy.

Further, in the method of setting the preheating time based on the filter temperature immediately before the start of regeneration, it is difficult to know the filter temperature accurately, and the optimum preheating is affected by the variation in the heating state of the particulates. Difficult to give to.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a filter regenerator having a highly accurate particulate combustion start or end detection capability while ensuring durability.

[0013]

In order to achieve the above object, the present invention provides a filter for collecting particulates contained in exhaust gas, a heating means for heating the particulates collected by the filter, and a heating means. Inside of the filter holding means arranged on the side surface of the filter, the auxiliary gas supply means for supplying the auxiliary gas for promoting the combustion of the particulates heated by the means, the microwave supply means for supplying the microwave to the space containing the filter. Alternatively, at least one of combustion start and combustion end of the particulates collected by the filter based on the microwave electromagnetic field intensity detection means for detecting the intensity of the microwave electromagnetic field existing outside and the detection value of the microwave electromagnetic field intensity detection means. Based on the determination result of the particulate combustion determination means and the particulate combustion determination means Of stage and co 燃気-supplying means and a filter regeneration control means for controlling at least one operation.

Further, there is provided a microwave supply means for supplying a microwave for dielectrically heating the particulates collected by the filter.

Further, auxiliary combustion gas supply means for supplying the auxiliary combustion gas to the filter, and pressure detection means for detecting the pressure of the auxiliary combustion gas at least on the upstream side of the filter in the flow direction of the auxiliary gas supplied by the auxiliary gas supply means. And a particulate combustion determination means for determining the start or end of combustion of the particulates collected by the filter based on the detection signal of the pressure detection means.

The above particulate combustion discriminating means is
When the detection value of the microwave electromagnetic field intensity detection means during the operation of the microwave supply means increases, it is determined that the particulate combustion has started.

The particulate combustion discriminating means discriminates when the detected value of the pressure detecting means during the operation of the auxiliary combustion gas supplying means decreases as the start of particulate combustion.

Further, the particulate combustion discriminating means is
When the detection value of the microwave electromagnetic field intensity detection means during the operation of the microwave supply means exceeds a predetermined value, it is determined that the particulate combustion has ended.

Furthermore, the particulate combustion discriminating means discriminates that the particulate combustion has ended when the detection value of the pressure detecting means during the operation of the auxiliary combustion gas supplying means becomes equal to or less than a predetermined value.

[0020]

In the above structure, the microwave electromagnetic field strength detecting means detects the microwave electromagnetic field strength existing inside or outside the filter holding means by the microwave generated by the microwave supplying means. When the predetermined amount of collected particulates is reached or every predetermined time cycle, the operations of the heating means and the auxiliary combustion gas supply means are controlled to heat and remove the particulates accumulated on the filter (filter regeneration). As the heating of the particulates by the heating means progresses with respect to the microwave electromagnetic field strength detection value at the beginning of heating, the dielectric loss of the particulates and the filter increases and the microwave electromagnetic field strength near the filter holding means increases. It weakens and the detected value decreases.

When the temperature of the particulates reaches the combustible temperature (about 600 ° C.), the particulates start to burn when the auxiliary gas flows. The flame generated by this combustion prevents microwaves from entering, so that microwaves are distributed by avoiding this combustion region. This distribution strengthens the microwave electromagnetic field strength existing near the filter holding means. Therefore, when the burning of particulates in the filter starts, the microwave electromagnetic field strength detection value increases. The particulate combustion determination means determines that the particulate combustion has started when the detected value of the microwave electromagnetic field strength starts increasing. Based on this determination result, the operations of the heating means and the auxiliary combustion gas supply means are controlled thereafter to expand the particulate combustion region.

The particulates become a gas by combustion and are removed from the filter. The area from which the particulates have been removed is cooled by the flow of the auxiliary combustion gas. As the particulate combustion approaches the end, the temperature of the particulate and the filter decreases, so that the dielectric loss of them decreases, the microwave electromagnetic field strength near the filter holding means increases, and the detected value increases. The microwave electromagnetic field intensity detection value at the time of completion of particulate combustion is set in advance, and when it exceeds this predetermined value, it is determined that the particulate combustion has ended. In response to this determination result, the operation of the heating means is stopped, the auxiliary gas supply means is operated for a predetermined time, the filter is cooled, and the regeneration is completed.

Since the microwave electromagnetic field intensity detecting means is configured to detect the intensity of the microwave electromagnetic field existing inside or outside the filter holding means arranged on the side surface of the filter, the exhaust gas flowing through the filter or the filter being regenerated. It can be isolated from high heat and guarantee the durability of detection.

Incidentally, the start or end of particulate combustion can also be discriminated from the change in pressure loss when the auxiliary combustion gas flowing through the filter flows. Here, the pressure detection means is provided upstream of the filter in the flow direction of the auxiliary combustion gas supplied by the auxiliary combustion gas supply means. The downstream side is not suitable for detecting the pressure because a high temperature auxiliary combustion gas flows due to the heat of particulate combustion. The pressure loss due to the flow path on the downstream side of the filter is almost constant, and the pressure on the upstream side of the filter and the pressure loss due to the filter can be approximated to a linear function. If the particulate heating progresses and the particulate combustion starts when the auxiliary combustion gas is flowing, the particulate is removed by the combustion, and the pressure loss of the filter, that is, the detection value of the pressure detecting means is significantly reduced. Thus, it is determined that the particulate combustion has started at the time when the detection value of the pressure detecting means starts to decrease.

As the particulate combustion progresses and approaches the end of the combustion, the remaining particulate decreases and the pressure loss of the filter, that is, the pressure detection value decreases. The pressure detection value at the end of combustion is set in advance, and it is determined that the particulate combustion has ended when the pressure detection value becomes equal to or less than this set value.

Here, since the pressure detecting means may be arranged at a distance from the exhaust gas flow path to detect the pressure, the pressure detecting means can be protected from the high heat of the exhaust gas and its durability can be guaranteed.

With the above-mentioned configuration, while maintaining the durability of the microwave electromagnetic field intensity detecting means or the pressure detecting means, it has a highly accurate particulate combustion start or end discriminating ability based on the microwave electromagnetic field intensity detected value or the pressure detected value. A filter regeneration device can be provided.

With this, since the start of particulate combustion can be determined with high accuracy, it is possible to prevent the particulate from remaining unburned due to insufficient preheating, and to prevent the particulate combustion temperature from becoming excessively high due to excessive preheating.

Furthermore, since the end of combustion of particulates can be determined with high accuracy, useless operation of the heating means and auxiliary gas supply means can be eliminated, and power consumption can be minimized. Further, it is possible to prevent an increase in the amount of the auxiliary combustion gas for cooling the filter before the end of the combustion of the particulates and prevent the combustion temperature from becoming excessively high.

From the above, the long-term durability of the filter can be guaranteed.

[0031]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, the exhaust gas discharged from the diesel engine 1 is guided through the exhaust pipe 2 to the filter 4 housed in the heating space 3. The filter 4 has a honeycomb structure and collects particulates contained in the exhaust gas when the exhaust gas passes through. The heating space 3 limits the space for substantially confining the microwaves by the microwave shielding means 5 and 6 having a punching hole structure or a honeycomb structure. Reference numeral 7 denotes a filter holding means provided between the outer periphery of the filter 4 and the tube wall 8 forming the heating space 3, which holds the filter 4 and suppresses heat transfer from the side surface of the filter 4. Exhaust gas is blocked from flowing through the space in which the filter holding means 7 is arranged. Although only one filter 4 is shown in the figure, the exhaust pipe 2 may be divided into a plurality of parts and a filter may be provided for each.

Microwaves generated by the microwave supply means 9 (heating means) are coaxial transmission line 10, coaxial waveguide conversion antenna 11, annular rectangular waveguide 12 and feed hole 13.
Power is supplied to the heating space 3 through 14, and the particulates collected by the filter 4 are dielectrically heated. Although the heating means is the microwave supply means 9 in this embodiment, a heating source such as an electric heater or a burner may be used. Reference numeral 15 is a drive power source for the microwave supply means 9, and the annular rectangular waveguide 12 has a structure in which power feeding holes 13 and 14 provided substantially facing the wall surface of the exhaust gas discharge pipe 16 are arranged at the ends. .
The coaxial waveguide conversion antenna 11 is arranged at a desired position of the annular rectangular waveguide 12 so that the microwave is radiated into the heating space 3 with a phase difference of 180 ° from the two feeding holes 13 and 14. are doing.

Reference numeral 17 denotes a microwave electromagnetic field strength detecting means for detecting the microwave electromagnetic field strength existing inside or outside the filter holding means 7 by the operation of the microwave supplying means 9, and has a coaxial line structure. The center conductor 18 of the coaxial line is arranged inside or outside the filter holding means 7. The microwave electromagnetic field intensity detecting means 17 or the center conductor 18 is isolated from the exhaust gas of the diesel engine 1 or the high heat during regeneration of the filter 4 by the filter holding means 7, so that their durability can be guaranteed. The electromagnetic field state of the microwave changes depending on the dielectric properties of the filter 4 and the particulates and the state of the flame generated by the particulate combustion. Based on the detection value of the microwave electromagnetic field intensity detection means 17, the start or end of the particulate combustion is determined. Be seen. It is desirable that the microwave electromagnetic field intensity detection means 17 is provided at a position where the microwave electromagnetic field intensity detection value monotonously decreases with an increase in the particulate trap weight in a desired particulate trap weight. Further, the weight of particulates collected by the filter 4 is calculated based on the detection signal of the microwave electromagnetic field intensity detecting means 17. Although only one microwave detecting means 17 is shown in the figure, a plurality of microwave detecting means 17 may be provided.

The valve 19 is normally a diesel engine 1
The exhaust gas discharged more is made to flow through the filter 4,
When the filter 4 is regenerated, the valve position is switched to allow the exhaust gas to flow through the exhaust branch pipe 20, and the exhaust gas is discharged through the muffler 21. The auxiliary combustion gas supply unit 22 supplies a gas containing oxygen (natural air in the present invention) into the heating space 3 through the gas transfer pipe 23. It is desirable that the auxiliary combustion gas supply unit 22 has a characteristic of supplying a constant amount of auxiliary combustion gas with respect to a change in the pressure loss of the object of auxiliary combustion gas supply. Further, in the present invention, in order to prevent the particulate combustion temperature from becoming excessively high, the auxiliary combustion gas supply amount is set to 4
The air is set to about 0 NL / min. The valves 24 and 25 control the flow of this auxiliary combustion gas to the filter 4. The valve 24 is arranged in a branch pipe 26 which is an exhaust path of the auxiliary combustion gas that has flowed through the filter 4 when the filter 4 is regenerated.
Is disposed between the heating space 3 and the exhaust pipe 27 that communicates with the atmosphere, and controls these two valves to allow an auxiliary combustion gas for promoting combustion of the particulates heated by the filter 4 during filter regeneration. The exhaust gas of the diesel engine 1 may be used as the auxiliary combustion gas.

Reference numeral 28 is a pressure detecting means for detecting the pressure of the auxiliary combustion gas during the operation of the auxiliary combustion gas supply means 22, and is provided on the upstream side of the filter 4 in the flowing direction of the auxiliary combustion gas supplied by the auxiliary combustion gas supply means 22. To be The pressure detection value at that position and the pressure loss due to the filter 4 can be approximated to a linear function. As the particulates are removed from the filter 4 by combustion, the pressure loss due to the filter 4 is reduced. Based on the detection value of the pressure detection means 28, the start or end of particulate combustion is determined.

By the way, as described above, in the present invention, in order to prevent the particulate combustion temperature from becoming excessively high, the auxiliary gas supply amount is set to 40 NL / min of air, and the pressure detected by the pressure detection means 28 is at most. 20 mm
It is Aq. On the other hand, when the diesel engine 1 operates and particulate collection concentration depends on the condition of the pipe, the pressure at the position of the pressure detecting means 28 is about 2000 mmAq, and the exhaust gas temperature reaches a maximum of 500 ° C., so the valve 29 protecting the pressure detecting means 28 is It is provided, and the durability of the pressure detecting means 28 can be guaranteed.

An exhaust gas temperature detecting means 30 is provided between the heating space 3 and the branch pipe 26 in the vicinity of the filter 4 of the exhaust pipe 2. The exhaust gas temperature is detected while the diesel engine 1 is operating, and the temperature of the auxiliary combustion gas flowing through the filter 4 is detected during the filter regeneration process. Reference numeral 31 is a filter regeneration control means for controlling the operations of the microwave supply means 9 and the auxiliary combustion gas supply means 22, and the signal detected by the microwave electromagnetic field intensity detection means 17 is sent to the particulate combustion determination means 33 via the coaxial line 32. Input. Further, the detection signal of the pressure detection means 28 is also input to the particulate combustion determination means 33. The particulate combustion discriminating means 33 discriminates the combustion start and the combustion end of the particulates collected by the filter 4 based on the detection value of the microwave electromagnetic field intensity detecting means 17 or the pressure detecting means 28. The particulate combustion discriminating means 33 is built in the regeneration control means 31.

A feature of the combustion determination using the microwave electromagnetic field intensity detecting means 17 is that it can be determined independently of the flow rate of the auxiliary combustion gas flowing through the filter 4. On the other hand, the combustion discrimination using the pressure detection means 28 is performed by the quality of the particulate (S
The feature is that it is not affected by the difference in the content ratio of OOT and SOF. If both are used together, more accurate combustion determination can be performed.

The operation of the above configuration will be described below with reference to FIGS.
Will be explained. First, at the time of collecting particulates, the valve 19, the valve 24, and the valve 25 are switched to predetermined positions, and the exhaust gas discharged from the diesel engine 1 is passed through the filter 4 to collect the particulates contained in the exhaust gas. Purify exhaust gas. Filter 4
When the amount of the particulates collected in is increased, the pressure loss in the filter 4 is increased, the load of the diesel engine 1 is increased, and in the worst case, it is stopped. Therefore, it is necessary to remove (filter regeneration) the particulates collected by the filter 4 under an appropriate particulate collection weight. Based on the detection signal of the microwave electromagnetic field intensity detection means 17, the filter regeneration control means 32 determines that the particulate collection weight has been reached, and the regeneration of the filter 4 is started. Next, at the time of filter regeneration, the valve 19, valve 24, and valve 25 are switched, and
During operation, the exhaust gas is bypassed through the exhaust branch pipe 20. Further, the valve 29 is opened to enable the pressure detection by the pressure detection means 28.

According to the present invention, the particulate combustion determination is made based on the detection value of the microwave electromagnetic field intensity detecting means 17 in which the microwave supplying means 9 is operating during the filter regeneration or the pressure detecting means 28 in which the supporting gas supplying means 22 is operating. Means 3
3 is characterized by discriminating the start and end of combustion of particulates. When the regeneration of the filter 4 is started, the microwave supply means 9 is continuously operated, and the microwaves generated thereby dielectrically heat the particulates collected in the filter 4. On the other hand, the auxiliary combustion gas supply means 22 is intermittently driven (for example, driven for 15 seconds and stopped for 45 seconds) to supply the auxiliary combustion gas to the filter 4. When the auxiliary combustion gas supply means 22 is continuously driven, the filter 4 is cooled and the start of particulate combustion is delayed, so intermittent driving is performed. Every time the intermittent driving of the auxiliary combustion gas supply means 22 is completed, the particulate combustion determination means 33 determines the start of combustion.

The heating of the particulates progresses and the filter 4
As the temperature rises, the microwave field strength detection value decreases, while the pressure detection value increases. Here, the pressure detection value increases because it is equivalent to that the auxiliary combustion gas is heated by the filter and expanded to increase the gas flow rate. When the particulates are heated and the filter temperature rises to reach the combustible temperature of the particulates, the combustion of the particulates starts when the auxiliary gas supply unit 22 operates, the microwave electromagnetic field intensity detection value increases, and the pressure detection value increases. Turns to decrease, and the particulate combustion determination means 33 determines that particulate combustion has started at time t _S shown in FIGS. After time t _s , the filter regeneration control means 32 continuously drives the microwave supply means 9, continuously drives the auxiliary gas supply means 22 for 30 seconds, and intermittently drives the auxiliary gas supply means 22 for 30 seconds to increase combustion of particulates.

Similar to the detection of combustion start, the auxiliary gas supply means 2
Every time the intermittent driving of 2 ends, the particulate combustion determination means 33 determines the end of combustion. As the combustion of the particulates further progresses and approaches the end of the combustion, the amount of accumulated particulates is reduced, the part of the filter 4 from which the particulates have been removed is cooled by the supporting gas, and the microwave electromagnetic field intensity detection value increases and the pressure detection value increases. Decreases. When the microwave electromagnetic field intensity detection value becomes equal to or higher than a predetermined value (V ₀ shown in FIG. 2) or the pressure detection value becomes equal to or lower than a predetermined value (P ₀ shown in FIG. 3), the particulate combustion determination means 33. Judges that the particulate combustion has ended at time t _E shown in FIGS. 2 and 3. After the time t _E , the filter regeneration control means 31 stops the operation of the microwave supply means 9 and continuously operates the auxiliary gas supply means 22 for a predetermined time to cool the filter 4 and
Playback ends.

With the above, the regeneration of the filter 4 is completed and the valve 1
9, the valve 24, the valve 25, and the valve 29 are switched again so that the exhaust gas can flow through the filter 4 just regenerated.

The operations of the microwave supply means 9 and the auxiliary combustion gas supply means 22 are not limited to those described in this embodiment. For example, the microwave output of the microwave supply means 9 can be varied and intermittent driving can be performed. Further, the supply flow rate of the auxiliary combustion gas supply means 22 can be changed, continuous drive can be performed, and the intermittent drive operation and stop time can be changed.

As described above, according to the filter regenerating apparatus of the embodiment of the present invention, while maintaining the durability of the microwave electromagnetic field intensity detecting means 17 or the pressure detecting means 28, the microwave electromagnetic field directly connected to the particulate combustion state. Since the particulate combustion determination means 33 performs the combustion determination based on the intensity detection value or the pressure detection value, it is possible to provide a filter regeneration device having a highly accurate particulate combustion start or end determination capability while ensuring durability.

Further, since the start of combustion of particulates can be determined with high accuracy, it is possible to prevent unburned particulates from remaining unburned due to insufficient preheating, and to prevent excessive heating of particulates due to excessive preheating.

Furthermore, since the end of the particulate combustion can be determined with high accuracy, it is possible to eliminate unnecessary operation of the microwave supply means 9 and the auxiliary combustion gas supply means 22 and to minimize power consumption. Further, it is possible to prevent an increase in the amount of the auxiliary combustion gas for cooling the filter before the end of the combustion of the particulates and prevent the combustion temperature from becoming excessively high.

From the above, the long-term durability of the filter 4 can be guaranteed.

[0050]

As described above, according to the filter regenerating apparatus of the present invention, the following effects can be obtained.

(1) Flow through the filter by utilizing the detection value of the microwave electromagnetic field intensity detecting means for detecting the intensity of the microwave electromagnetic field existing inside or outside the filter holding means arranged on the side surface of the filter. It is possible to provide a filter regenerator having a highly accurate particulate combustion start or end determination capability that guarantees durability independently of the flow rate of auxiliary gas.

(2) Since the microwave supply means performs dielectric heating of the particulates, it is not necessary to provide heating means for heating the particulates, and the structure of the device can be simplified.

(3) By using the detection value of the pressure detecting means for detecting the pressure of the auxiliary combustion gas at least upstream of the filter in the flow direction of the auxiliary combustion gas supplied by the auxiliary combustion gas supply means, the pressure detection means is heated to a high temperature. Since it may be placed away from the exhaust gas of the exhaust gas and detected, durability can be guaranteed and the filter regeneration device has a highly accurate particulate start or end determination capability that is not affected by the quality of the particulate. Can be provided.

(4) Based on the detection value of the microwave electromagnetic field intensity detecting means or the pressure detecting means, the particulate combustion discriminating means can discriminate the start of the particulate combustion, and the optimum preheating of the filter until the particulate is ignited. Can be given. As a result, it is possible to prevent unburned particulates from remaining unburned due to insufficient preheating of the particulates, or to prevent excessive combustion temperature of the particulates due to excessive preheating, and to maintain the filter performance for a long period of time.

(5) Based on the detection value of the microwave electromagnetic field intensity detecting means or the pressure detecting means, the particulate combustion discriminating means can discriminate the end of the particulate combustion, and the particulate combustion can be regenerated at the optimum time. As a result, useless operation of the heating means and the auxiliary combustion gas supply means can be eliminated, and power consumption can be minimized. Further, it is possible to prevent an increase in the amount of the auxiliary combustion gas for cooling the filter before the end of the combustion of the particulates, and to prevent the particulates combustion temperature from becoming excessively high.

[Brief description of drawings]

FIG. 1 is a block diagram of a filter regeneration device showing an embodiment of the present invention.

FIG. 2 is a diagram showing an operation example of a microwave supply unit and an auxiliary combustion gas supply unit during filter regeneration according to an embodiment of the present invention, and a variation example of a microwave electromagnetic field intensity detection value.

FIG. 3 is a diagram showing an operation example of a microwave supply means and an auxiliary combustion gas supply means and a change example of a pressure detection value during filter regeneration according to an embodiment of the present invention.

[Explanation of symbols]

 4 Filter 9 Microwave Supply Means (Heating Means) 17 Microwave Electromagnetic Field Strength Detection Means 22 Supporting Gas Supply Means 28 Pressure Detection Means 31 Filter Regeneration Control Means 33 Particulate Combustion Discrimination Means

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location F02B 77/08 ZAB M (72) Inventor Masao Noguchi 1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric Industrial Co., Ltd. In-house (72) Inventor Norio Bada 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (7)

[Claims] 1. A filter for collecting particulates contained in exhaust gas, a heating means for heating the particulates collected by the filter, and an auxiliary combustion gas for promoting combustion of the particulates heated by the heating means. For supplying the supplementary gas, microwave supplying means for supplying microwaves to the space containing the filter, and the strength of the microwave electromagnetic field existing inside or outside the filter holding means arranged on the side surface of the filter. Microwave electromagnetic field intensity detection means for detecting, and particulate combustion determination means for determining at least one of combustion start and combustion end of the particulates collected by the filter based on the detection value of the microwave electromagnetic field intensity detection means The heating means and the auxiliary combustion gas based on the determination result of the particulate combustion determination means. Filter regeneration apparatus provided with the filter regeneration control means for controlling at least one operation of the supply means. 2. A filter for collecting particulates contained in exhaust gas, a microwave supply means for supplying microwaves for dielectrically heating the particulates collected by the filter, and the microwave supply means for heating. Supporting gas supply means for supplying a supporting gas for promoting the combustion of the particulates, and microwave electromagnetic field strength detecting means for detecting the strength of the microwave electromagnetic field existing inside or outside the filter holding means arranged on the side surface of the filter. When,
A particulate combustion determination means for determining at least one of the combustion start and the combustion end of the particulates collected by the filter based on the detection value of the microwave electromagnetic field intensity detection means, and the determination result of the particulate combustion determination means A filter regeneration device comprising: a microwave regeneration means and a filter regeneration control means for controlling the operation of at least one of the auxiliary gas supply means. 3. A filter for collecting particulates contained in exhaust gas, heating means for heating the particulates collected by the filter, and promotion of combustion of particulates heated by the microwave supply means. Of the auxiliary combustion gas supply means for supplying the auxiliary combustion gas, the pressure detection means for detecting the pressure of the auxiliary combustion gas at least on the upstream side of the filter in the flow direction of the auxiliary combustion gas supplied by the auxiliary combustion gas supply means, and the pressure detection means. The particulate combustion determination means for determining at least one of the combustion start and the combustion end of the particulates collected by the filter based on the detection signal, and the heating means and the above based on the determination result of the particulate combustion determination means. A filter provided with a filter regeneration control means for controlling the operation of at least one of the auxiliary gas supply means. Reproducing apparatus. 4. The filter regeneration device according to claim 1, wherein the particulate combustion determination means determines when the detection value of the microwave electromagnetic field intensity detection means during the operation of the microwave supply means increases as the particulate combustion start. 5. The particulate combustion discrimination means discriminates as the particulate combustion start when the detection value of the pressure detection means during the operation of the auxiliary gas supply means decreases.
The filter regeneration device described. 6. The particulate combustion discriminating means discriminates when the detected value of the microwave electromagnetic field intensity detecting means during the operation of the microwave supplying means exceeds a predetermined value as the particulate combustion end. Filter regenerator. 7. The filter regeneration device according to claim 3, wherein the particulate combustion determination means determines that the particulate combustion has ended when the detection value of the pressure detection means during the operation of the auxiliary combustion gas supply means becomes equal to or less than a predetermined value.