JP2002147220A - Filter heating and refreshing method for dpf device and dpf device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filter heating and refreshing method for a DPF device and the DPF device, separating high temperature gas and low temperature gas from exhaust gas by applying the vortex effect being thermodynamically proved already, and utilizing heat of the high temperature gas for heating a filter or burning particulates accumulated in the filter. SOLUTION: This method is a method for heating the filter 3 capturing particulates in exhaust gas G1 in an exhaust passage 2 of an internal combustion engine. Exhaust gas G2 having passed through the filter 3 is separated into high temperature gas G3 and low temperature gas G4 by utilizing the vortex effect, and the separated high temperature gas G3 is returned to the filter 3 to heat the filter 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for heating and regenerating a filter of a DPF device for collecting particulates discharged from a diesel engine such as a truck and a bus, and a DPF device.

More specifically, the present invention relates to a filter heating and regeneration method of a DPF device and a DPF device that utilize a part of heat energy of exhaust gas after passing through a filter to increase the temperature of the filter.

[0003]

2. Description of the Related Art Exhaust gas emitted from a diesel engine of an automobile or the like contains particulates (PM: particulate matter) of several μm to several tens μm which are compounds of carbon and unburned HC. Therefore, the removal of these particulates is important from the aspect of pollution prevention, and a DPF (Diesel Particulate Filter) is used to remove the particulates, and a DPF device equipped with the DPF is used. Is disposed in the exhaust passage of the engine.

The DPF is made of cordierite, a porous metal body (Celmet), an inorganic fiber material, or the like.
If the particulates continue to be collected, the filter will be clogged by the collected particulates. Therefore, it is necessary to remove the collected particulates causing the clogging of the DPF by some method. .

In the prior art, this particulate removal method is mainly performed by the following three methods.

In the first method, a filter is formed of a ceramic laminated filter, and while the exhaust passage is switched by a plurality of filters, particulates are collected by one filter and the other filter is heated by an electric heater. This is a method in which particulate collection and filter regeneration are alternately repeated while burning the accumulated particulates.

In a second method, a solid filter is used as a filter, and this solid filter is combined with an oxidation catalyst,
This is a method of treating particulates by a chemical reaction based on catalysis and heat generated by the chemical reaction.

The third method is a method of treating particulates by using a solid filter and an additive other than fuel to promote the burning of the particulates.

[0009]

However, in the first method, two or more filter units are required, and a heater unit for regeneration and a generator dedicated to the heater unit are indispensable. In particular, when retrofitting to an existing truck or bus, there is a problem that it is difficult to additionally install the truck or bus, and that a cost increase cannot be avoided.

Further, the second method has a problem that the cost is increased due to the necessity of an oxidation catalyst and a problem such as a regenerating method in a region where the exhaust temperature is low and a chemical reaction hardly occurs.

In the third method, an oxidation catalyst is required and the cost is unavoidable, and an additive for particulate combustion is required separately from the fuel. Has the problem of being unsuitable.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to reduce the temperature of an exhaust gas to a high-temperature gas by applying a thermodynamically proven vortex effect. Generates and separates cold gas,
The heat of the high-temperature gas can be used for heating the filter and burning particulates accumulated in the filter.
An object of the present invention is to provide a method for heating and regenerating a filter of a PF device and a DPF device.

[0013]

Means for Solving the Problems [Method of Heating Filter of DPF Apparatus] DPF to achieve the above object
(Diesel Particulate Filter) A filter heating method for a device is a method for heating a filter for collecting particulates in exhaust gas in an exhaust passage of an internal combustion engine, and using a vortex effect of exhaust gas passing through the filter. Then, the high temperature gas and the low temperature gas are separated, and the separated high temperature gas is returned to the filter to heat the filter.

According to this configuration, the heat of the exhaust gas after passing through the filter can be used for heating the filter, so that the temperature of the filter can be maintained at a high temperature. for that reason,
It can be used as a part or all of a heat source for promoting a chemical reaction based on catalysis or for regenerating collected particulates.

[Filter regeneration method of DPF device]
A method of regenerating a filter of a DPF device for achieving the above object is a method of regenerating a filter for trapping particulates in exhaust gas in an exhaust passage of an internal combustion engine, wherein the exhaust gas passing through the filter is regenerated. Is separated into a high-temperature gas and a low-temperature gas by using a vortex effect, and the separated high-temperature gas is refluxed to the filter to heat the filter. By the heating, the temperature of the filter is reduced to the combustion temperature of particulates. By heating as described above, the particulate matter collected in the filter is burned and removed.

According to this configuration, the temperature of the filter is heated to a temperature equal to or higher than the burning temperature of the particulates, and the particulates collected by the filter can be removed by combustion.
DPF can be continuously regenerated.

[DPF device] A DPF device for achieving the above-mentioned object is configured as follows.

A DPF device comprising: a filter for collecting particulates in exhaust gas in an exhaust passage of an internal combustion engine; and a temperature raising means for the filter, wherein the temperature raising means comprises an exhaust gas passing through the filter. Vortex effect generating means for separating the high-temperature gas and the low-temperature gas using the vortex effect, and heating means for heating the filter using the high-temperature gas separated by the vortex effect generating means.

According to this configuration, since the heat of the exhaust gas after passing through the filter can be used for heating the filter, the temperature of the filter can be maintained at a high temperature.

Examples of the heating means include a high-temperature gas passage provided around the filter and a heat exchanger provided at the upstream side of the filter for heating exhaust gas. The high-temperature gas is returned to the filter. It's easy.

That is, in the above DPF device, the heating means is constituted by a recirculation passage for recirculating the high-temperature gas generated by the vortex effect generating means to an upstream side of the filter.

According to this configuration, the filter can be efficiently heated from inside the filter with a very simple configuration.

In the above-mentioned DPF device, the vortex effect generating means may include an expansion swivel part having an exhaust gas inlet and a low-temperature gas outlet, a swirl tube connected to the expansion swivel part, and the other end of the swirl tube. And a flow control valve portion having a high-temperature gas outlet, the expansion swirling portion being disposed inside the expansion chamber for adiabatically expanding the exhaust gas introduced from the exhaust gas inlet. A swirl hole formed from the center side to the outer circumference side for sending the exhaust gas to the swirl tube as a high-speed swirl flow; and a low-temperature swirl member provided at the center side. It is formed having a gas discharge passage, the flow rate adjusting valve portion is a valve that adjusts the flow rate of the high-temperature gas on the outer peripheral side in the swirl tube is discharged from the high-temperature gas outlet, A case, a valve body which is inserted into the valve casing, is formed by a valve actuator that adjusts the valve opening by driving the valve body.

With this vortex effect generating means, the exhaust gas can be separated into a high-temperature gas and a low-temperature gas by utilizing the vortex effect.

[Vortex Effect] The vortex effect will be described below with reference to FIG.

The vortex effect is to generate a high-temperature gas and a low-temperature gas from exhaust gas by applying the principle of adiabatic expansion by centrifugal force.

Exhaust gas entering the expansion swirling section from the inlet of the vortex effect generating means is adiabatically expanded in the expansion chamber, is swirled by the swirl piece, flows through the swirling tube, and flows toward the flow control valve section. .

At this time, the high-speed swirling flow is pressed against the inner wall of the swirling tube by the centrifugal force, and a pressure difference from the central portion is generated. A part is formed in a pipe shape.

Since the swirling velocity of the vortexed exhaust gas is the same at both the center and the outside, the angular velocity at the center is increased, the energy level is increased, and at the same time, heat is transferred to the outside as heat. The temperature increases in the outer peripheral portion, and the temperature of the swirling flow in the central portion decreases.

The high-temperature gas on the outside that has reached the flow control valve portion is discharged from the outer periphery of the valve body, and the low-temperature gas on the inside is hindered by the valve body and rebounds by the valve body, and a pipe-shaped portion having a low pressure at the center. Through the cold gas discharge passage of the swirl piece.

In the flow control valve section, when the valve element is moved in the direction A and opened slightly, the outermost thin layer of high-temperature gas is discharged, and when the valve element is further opened, low-temperature gas near the center is also discharged. Therefore, the temperature and the flow rate of the gas returned to the filter can be adjusted by the valve opening.

Incidentally, regarding this vortex effect,
In a basic experiment using the vortex effect generating means according to the present invention, air at −47 ° C. to + 24 ° C. was supplied.
High, high-temperature air from + 3.9 ° C. to + 87 ° C. has been obtained, confirming the occurrence of the vortex effect.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for heating and regenerating a filter of a DPF according to an embodiment of the present invention and a DPF will be described below with reference to the drawings.

[Configuration of DPF Device] First, the DPF of the present invention
A DPF device that can execute the filter heating method and the regeneration method of the PF device will be described.

As shown in FIG. 1, this DPF device 1
A filter 3 provided in an exhaust passage 2 of the internal combustion engine, a high-temperature gas generator 5 which is a vortex effect generating means provided in an exhaust passage 4 downstream of the filter 3, and a gas discharged from the high-temperature gas generator 5 Hot gas (hot air) G3
A recirculation passage 6 for recirculating the gas to the upstream side of the filter 3 and an exhaust passage 7 for discharging a low-temperature gas (cool air) G4 discharged from the high-temperature gas generator 5 to the outside.

The filter 3 is made of silicon carbide (SiC)
And a solid filter made of cordierite,
The particulate matter (PM) in the exhaust gas G1 discharged from the internal combustion engine is collected.

As shown in FIG. 1 and FIG. 2, the high-temperature gas generator 5 is connected to the expansion swivel part 51, a swivel tube (separation pipe) 52 connected thereto, and the other end of the swivel tube 52. Flow control valve (hot air control valve) 5
3 are formed.

As shown in FIG.
Has an exhaust gas inlet 51a and a low temperature gas outlet 54c,
An expansion chamber 51b for adiabatically expanding the exhaust gas G entering from the exhaust gas inlet 51a, and a swirl piece (vortex generation member) 54 disposed inside the expansion chamber 51b. The swirl piece 54 has a swirl hole 54a penetrating from the center side to the outer peripheral side, and a low-temperature gas discharge passage 54b provided at the center side, and the exhaust gas G2 is swirl hole 54a.
The exhaust gas G2 is sent to the swirling tube 52 as a high-speed swirling flow by passing through.

The swivel tube 52 is formed as a cylinder. The flow rate adjustment valve section 53 is a valve that adjusts the flow rate when the high temperature gas G3 on the outer peripheral side in the swirl tube 52 is discharged from the high temperature gas outlet 53c.
3a, a valve element 53b having a conical surface inserted into the valve case 53a, and a valve actuator (not shown) for driving the valve element to adjust the valve opening.

As shown in FIG. 1, a recirculation passage 6 serving as a heating means for heating the filter is provided with an exhaust gas outlet 53c of a flow control valve 53 of the high-temperature gas generator 5 and a high-temperature gas inlet 3c of the filter 3. The high temperature gas G3 discharged from the high temperature gas generator 5 is returned to the upstream side of the filter 3.

[Flow of Exhaust Gas in DPF Apparatus and Effects] According to the DPF apparatus 1 having the above configuration, as shown in FIG. 1, the exhaust gas G1 discharged from the internal combustion engine is filtered from the exhaust passage 2 through the exhaust passage 2. The exhaust gas G1 is introduced into the exhaust gas inlet 3a, passes through the filter body 3b, and can collect and remove particulates in the exhaust gas G1.

Then, the exhaust gas G2 from which the particulates have been removed and purified is supplied to the exhaust gas outlet 3e of the filter 3.
And enters the high-temperature gas generator 5 via the exhaust passage 4.

As shown in FIG. 2, in the high-temperature gas generator 5, the exhaust gas G2 entering from the inlet 51a of the expansion swirling part 51 is adiabatically expanded in the expansion chamber 51b, and the vortex piece 5
The high-speed swirling flow is sent to the swirling tube 52 by the fourth swirling hole 54a.

The exhaust gas G2 sent into the swirling tube 52 is separated into a high-temperature gas G3 on the outer peripheral side and a low-temperature gas G4 on the central side by the above-mentioned vortex effect, and reaches the flow regulating valve section 53 while swirling. . The high-temperature gas G3 has a higher temperature than the exhaust gas G2, and the low-temperature gas G4 has a lower temperature than the exhaust gas G2.

The high-temperature gas G 3 arriving at the flow control valve portion 53 is discharged from the space between the valve body 53 b and the valve case 53 a via the high-temperature gas outlet 53 c, passes through the reflux passage 6, and enters the high-temperature gas inlet of the filter 3. 3c, filter 3
Heat.

The flow rate of the high-temperature gas G3 is adjusted by the degree of opening of the flow rate adjusting valve portion 53. Since this flow rate is closely related to the temperature of the high-temperature gas, the flow rate at which the filter 3 can be heated most efficiently is provided. The valve opening is adjusted and controlled so that

On the other hand, the low-temperature gas G3 arriving at the flow control valve portion 53 rebounds at the valve body 53b, passes through a pipe-shaped portion having a low central pressure, and flows from the low-temperature gas discharge passage 54b of the swirl piece 54 to the low-temperature gas. Exhaust passage 7 via outlet 54c
Is discharged to the outside.

Therefore, the filter 3 can be heated by generating the high-temperature gas G3 from the exhaust gas G2. That is, the exhaust gas G2 that has passed through the filter 3 can be separated into a high-temperature gas G3 and a low-temperature gas G4 by using the vortex effect, and the separated high-temperature gas G3 can be returned to the filter 3 to heat the filter 3. .

The high-temperature gas G3 re-introduced into the filter 3 raises the temperature inside the filter 3. By repeating this, the internal temperature of the filter 3 is raised to 600 ° C. or higher, which is the burning temperature of particulates. can do.

When the temperature reaches the burning temperature of the particulates, the particulates start burning, so that the particulates collected by the filter 3 burn, are discharged as gas, and the inside of the filter 3 is discharged. Washed.

During the burning of the particulates, the generation of the high-temperature gas G3 and the recirculation to the filter 3 can be continued without interruption, so that the trapped particulates can be burned and removed sequentially, so that the filter 3 Clogging due to the collection of water can be prevented.

That is, the exhaust gas G passing through the filter 3
2 is separated into a high-temperature gas G3 and a low-temperature gas G4 by using a vortex effect, and the separated high-temperature gas G3 is returned to the filter 3 to heat the filter 3, and this heating causes
By heating the temperature of the filter 3 to a temperature equal to or higher than the burning temperature of the particulates, the particulates collected by the filter 3 can be burned and removed.

[0053]

As described above, the DP according to the present invention is
According to the filter heating and regeneration method of the F apparatus and the DPF apparatus, the following effects can be obtained.

By applying the thermodynamically proven vortex effect, a high-temperature gas and a low-temperature gas are generated and separated from the exhaust gas, and the heat of the high-temperature gas is heated by the filter and the particulates deposited in the filter are heated. It can be used for combustion.

DPF that can use this vortex effect
The apparatus does not require a heater for regenerating the filter or an external power supply for the heater, so that the cost can be reduced.

Further, since this DPF device has few moving parts and electric parts, the failure rate is extremely low. In addition, since it is merely disposed in the middle of the exhaust pipe, it is not necessary to additionally install another component such as a generator, so that retrofitting can be easily performed.

In addition, the filter heating method and the filter regeneration method of the DPF apparatus according to the present invention can be applied to a continuous regeneration type DPF for constantly regenerating a filter, and also to a regeneration after particulate clogging becomes large. The present invention is also applicable to an intermittent DPF for processing.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a DPF device according to an embodiment of the present invention.

FIG. 2 is a side sectional view of a high-temperature gas generator of the vortex effect generator of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 DPF apparatus 2 Exhaust passage 3 Filter 5 High temperature gas generator (Vortex effect generating means) 6 Reflux passage (Heating means) 51 Expansion swirling part 51a Exhaust gas inlet 52 Swirling tube 53 Flow rate adjusting valve part 53a Valve case 53b Valve body 53c High temperature Gas outlet 54 Eddy flow piece (eddy current generating member) 54a Swirl hole 54b Low temperature gas discharge passage 54c Low temperature gas outlet

Claims (5)

[Claims] 1. A method for heating a filter for trapping particulates in exhaust gas in an exhaust passage of an internal combustion engine, wherein the exhaust gas passing through the filter is heated and cooled using a vortex effect. And heating the filter by refluxing the separated high-temperature gas to the filter. 2. A method for regenerating a filter for trapping particulates in exhaust gas in an exhaust passage of an internal combustion engine, wherein the exhaust gas passing through the filter is subjected to a high-temperature gas and a low-temperature gas using a vortex effect. And the separated high-temperature gas is refluxed to the filter to heat the filter. By the heating, the temperature of the filter is heated to a temperature equal to or higher than the burning temperature of the particulates, and the particles collected by the filter are heated. D characterized by burning and removing curates
A filter regeneration method for a PF device. 3. A DPF device comprising: a filter for trapping particulates in exhaust gas in an exhaust passage of an internal combustion engine; and a temperature raising means for the filter, wherein the temperature raising means comprises:
Vortex effect generating means for separating the exhaust gas passing through the filter into a high-temperature gas and a low-temperature gas using a vortex effect, and heating for heating the filter using the high-temperature gas separated by the vortex effect generating means A DPF device comprising: 4. The DPF apparatus according to claim 3, wherein said heating means is a recirculation passage for recirculating the high-temperature gas generated by said vortex effect generating means to an upstream side of said filter. 5. A vortex effect generating means, comprising: an expansion swirler having an exhaust gas inlet and a low-temperature gas outlet; a swirl tube connected to the expansion swirler; and a high-temperature gas connected to the other end of the swirl tube. An expansion chamber for adiabatically expanding exhaust gas introduced from an exhaust gas inlet, and a vortex generating member disposed inside the expansion chamber. The swirling flow generating member has a swirling hole provided from the center side to send the exhaust gas into a high-speed swirling flow to the swirling tube from the center side to the outer peripheral side, and a low-temperature gas discharge passage provided at the center side. The flow rate adjusting valve portion is a valve that adjusts a flow rate of the high-temperature gas on the outer peripheral side in the swirl tube discharged from the high-temperature gas outlet. The DPF device according to claim 3, wherein the DPF device is formed of a valve body that is driven and a valve actuator that drives the valve body to adjust a valve opening.