JP4035954B2 - DPF device filter heating and regeneration method and DPF device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a filter heating and regeneration method for a DPF device for collecting particulates discharged from diesel engines such as trucks and buses, and a DPF device.
[0002]
More specifically, the present invention relates to a filter heating and regeneration method for a DPF device that uses a part of heat energy of exhaust gas after passing through a filter to increase the temperature of the filter, and a DPF device.
[0003]
[Prior art]
The exhaust gas emitted from diesel engines such as automobiles contains particulates (PM: particulate matter) of several μm to several tens of μm, which are composites of carbon and unburned HC. The removal of curate is important from the aspect of pollution prevention, and DPF (diesel particulate filter: Diesel Particulate Filter) is used for the removal of this particulate, and the DPF device equipped with this is the exhaust passage of the engine. It is arranged.
[0004]
This DPF is composed of cordierite, metal porous material (Celmet), inorganic fiber material, etc., but if the particulates continue to be collected, the filter will be clogged by the collected particulates. It is necessary to remove the collected particulate matter causing the clogging of the DPF by some method.
[0005]
In the prior art, this particulate removal method is mainly performed by the following three methods.
[0006]
In the first method, the filter is formed of a ceramic multilayer filter, and particulates are collected by one filter while the exhaust passage is switched by a plurality of filters, and the other filter is heated by an electric heater and deposited. This is a method of alternately repeating particulate collection and filter regeneration while burning the particulates.
[0007]
The second method is a method in which a solid filter is used as a filter, and the solid filter and the oxidation catalyst are combined to treat the particulates by a chemical reaction based on the catalytic action and heat generated by the chemical reaction.
[0008]
The third method is a method of treating particulates by promoting combustion of particulates using an additive different from the solid filter and the fuel.
[0009]
[Problems to be solved by the invention]
However, in the first method, two or more filter units are required, and there is a problem that a heater unit for regeneration and a generator dedicated to the heater unit are indispensable. When retrofitting to a bus, there are problems that it is difficult to install and additional cost is unavoidable.
[0010]
Further, the second method has a problem that an oxidation catalyst is required and the cost is increased, and there are problems such as a regeneration method in a region where the exhaust temperature is low and a chemical reaction hardly occurs.
[0011]
Also in the third method, an oxidation catalyst is required and an increase in cost is inevitable, and an additive for particulate combustion is required in addition to the fuel, so that it is not suitable for retrofit as in the first method. There is a problem that.
[0012]
The present invention has been made to solve the above-mentioned problems of the prior art, and its purpose is to apply hot and cold gases from exhaust gas by applying a vortex effect that has been demonstrated thermodynamically. An object of the present invention is to provide a filter heating and regeneration method for a DPF device and a DPF device that can use the heat of the high-temperature gas that is generated and separated to heat the filter and burn particulates accumulated in the filter.
[0013]
[Means for Solving the Problems]
[DPF device filter heating method]
A filter heating method of a DPF (diesel particulate filter) device for achieving the above object is a method of heating a filter that collects particulates in exhaust gas in an exhaust passage of an internal combustion engine, The exhaust gas that has passed through the filter is separated into 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.
[0014]
With 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. Therefore, it can be used as a part or all of a heat source for promoting a chemical reaction based on a catalytic action or regenerating collected particulates.
[0015]
[Filter regeneration method of DPF device]
Further, a filter regeneration method for a DPF device for achieving the above object is a method for regenerating a filter that collects particulates in exhaust gas in an exhaust passage of an internal combustion engine, and has passed through the filter. The exhaust gas is separated into a high-temperature gas and a low-temperature gas using the vortex effect, the separated high-temperature gas is refluxed to the filter, the filter is heated, and the temperature of the filter is reduced by the heating. It is configured to heat up to the combustion temperature or higher to burn and remove the particulates collected in the filter.
[0016]
According to this configuration, since the temperature of the filter is heated to the particulate combustion temperature or higher and the particulates collected in the filter can be removed by combustion, the DPF can be continuously regenerated.
[0017]
[DPF equipment]
A DPF device for achieving the above object is configured as follows.
[0018]
A DPF device having 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,
The temperature raising means uses the vortex effect generating means for separating the exhaust gas that has passed through the filter into a high temperature gas and a low temperature gas using the vortex effect, and the high temperature gas separated by the vortex effect generating means. And heating means for heating the filter.
[0019]
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.
[0020]
As this heating means, a high-temperature gas passage provided around the filter and a heat exchanger for heating the exhaust gas provided upstream of the filter can be considered, but it is easy to recirculate the high-temperature gas to the filter. It is.
[0021]
That is, in the above DPF device, the heating means is constituted by a reflux passage for returning the high temperature gas generated by the vortex effect generating means to the upstream side of the filter.
[0022]
According to this configuration, the filter can be efficiently heated from the inside of the filter with a very simple configuration.
[0023]
Further, in the above DPF device, the vortex effect generating means is connected to an expansion swirling portion having an exhaust gas inlet and a low temperature gas outlet, a swirling tube connected to the expansion swirling portion, and the other end side of the swirling tube. A flow regulating valve portion having a hot gas outlet,
The expansion swirl is formed by an expansion chamber that adiabatically expands exhaust gas introduced from an exhaust gas inlet, and a vortex generator that is disposed inside the expansion chamber.
The eddy current generating member is formed to have a swirl hole that is provided to penetrate the exhaust gas from the center side to the outer periphery side in a high-speed swirl flow, and a low-temperature gas discharge passage that is provided on the center side. And
The flow rate adjusting valve part is a valve for adjusting a flow rate at which the high temperature gas on the outer peripheral side in the swivel tube is discharged from the high temperature gas outlet, a valve case, and a valve body inserted in the valve case, And a valve actuator that adjusts the valve opening by driving the valve body.
[0024]
By this vortex effect generating means, the exhaust gas can be separated into a high temperature gas and a low temperature gas using the vortex effect.
[0025]
[Vortex effect]
Hereinafter, the vortex effect will be described with reference to FIG.
[0026]
The vortex effect is to generate high-temperature gas and low-temperature gas from exhaust gas by applying the principle of adiabatic expansion by centrifugal force.
[0027]
The exhaust gas that has entered the expansion swirling unit from the inlet of the vortex effect generating means is adiabatically expanded in the expansion chamber, becomes a vortex flow by the vortex flow piece, passes through the swirl tube, and flows toward the flow rate adjusting valve unit.
[0028]
At this time, the high-speed swirling flow is pressed against the inner wall of the swirling tube by centrifugal force, creating a pressure difference from the center, and the center of the vortex is the same as the typhoon, and the low pressure part is piped to the center of the swirling tube. It is formed in a shape.
[0029]
Since the swirling flow velocity of the exhaust gas that has become the vortex is the same at the center and the outside, the angular velocity at the center increases and the energy level increases, and at the same time, heat is transferred to the outside, so the outer peripheral part is The temperature increases and the temperature of the swirling flow in the center decreases.
[0030]
The outer high temperature gas that has reached the flow control valve is discharged from the outer periphery of the valve body, and the inner low temperature gas is blocked by the valve body, bounces off the valve body, and passes through a pipe-shaped part with a low central pressure. , Discharged through the low temperature gas discharge passage of the vortex piece.
[0031]
When the valve body is moved in the direction A and slightly opened, the outermost thin layer of hot gas is discharged, and when it is further opened, the low-temperature gas close to the center is also discharged. Therefore, the temperature and flow rate of the gas returned to the filter can be adjusted by the valve opening.
[0032]
In addition, about this vortex effect, in a basic experiment using the vortex effect generating means according to the present invention, air of −47 ° C. to + 24 ° C. is supplied, and in an approximately linear relationship, an average of 50 ° C. from the supplied air. High temperature air from + 3.9 ° C. to + 87 ° C. can be obtained, and the occurrence of the vortex effect has been confirmed.
[0033]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a filter heating and regeneration method and a DPF device of a DPF device according to an embodiment of the present invention will be described with reference to the drawings.
[0034]
[Configuration of DPF device]
First, a DPF device capable of implementing the filter heating method and the regeneration method of the DPF device of the present invention will be described.
[0035]
As shown in FIG. 1, the DPF device 1 includes a filter 3 provided in an exhaust passage 2 of an internal combustion engine and high-temperature gas generation that is a vortex effect generating means provided in an exhaust passage 4 on the downstream side of the filter 3. A recirculation passage 6 for recirculating the high-temperature gas (hot air) G3 discharged from the high-temperature gas generator 5 to the upstream side of the filter 3, and a low-temperature gas (cold air) G4 discharged from the high-temperature gas generator 5; And an exhaust passage 7 for discharging to the outside.
[0036]
The filter 3 is a solid filter formed of silicon carbide (SiC) or cordierite, and collects particulates (PM) in the exhaust gas G1 discharged from the internal combustion engine.
[0037]
As shown in FIGS. 1 and 2, the hot gas generator 5 includes an expansion swivel 51, a swivel tube (separation pipe) 52 connected to the expansion swivel 51, and a flow rate adjustment valve connected to the other end of the swirl tube 52. Part (hot air adjusting valve) 53.
[0038]
As shown in FIG. 2, the expansion swivel 51 has an exhaust gas inlet 51a and a low-temperature gas outlet 54c, and an expansion chamber 51b that adiabatically expands the exhaust gas G that has entered from the exhaust gas inlet 51a, and the expansion chamber 51b. And a vortex flow piece (vortex flow generating member) 54 disposed in the inside. The swirl piece 54 is formed to have a swivel hole 54a provided penetrating from the center side to the outer peripheral side and a low-temperature gas discharge passage 54b provided on the center side, and the exhaust gas G2 passes through the swirl hole 54a. As a result, the exhaust gas G2 is sent to the swirl tube 52 as a high-speed swirl flow.
[0039]
The swivel tube 52 is formed in a cylindrical shape. The flow rate adjusting valve portion 53 is a valve that adjusts the flow rate when the high temperature gas G3 on the outer peripheral side in the swivel tube 52 is discharged from the high temperature gas outlet 53c, and includes a valve case 53a and a valve case 53a. It is formed by a valve body 53b having a conical surface to be inserted and a valve actuator (not shown) that drives the valve body to adjust the valve opening degree.
[0040]
The reflux passage 6 that is a heating means for heating the filter connects the exhaust gas outlet 53c of the flow rate adjusting valve portion 53 of the hot gas generator 5 and the hot gas inlet 3c of the filter 3 as shown in FIG. The hot gas G3 discharged from the hot gas generator 5 is recirculated to the upstream side of the filter 3.
[0041]
[Flow and effects of exhaust gas in DPF equipment]
According to the DPF device 1 having the above configuration, as shown in FIG. 1, the exhaust gas G1 discharged from the internal combustion engine is introduced from the exhaust passage 2 into the exhaust gas inlet 3a of the filter 3 and passes through the filter body 3b. The particulates in the exhaust gas G1 can be collected and removed.
[0042]
Then, the particulate gas is removed and the purified exhaust gas G2 is discharged from the exhaust gas outlet 3e of the filter 3 and enters the high temperature gas generator 5 through the exhaust passage 4.
[0043]
As shown in FIG. 2, in this high temperature gas generator 5, the exhaust gas G <b> 2 entering from the inlet 51 a of the expansion swirl 51 is adiabatically expanded in the expansion chamber 51 b, and at a high speed swirl flow by the swirl hole 54 a of the vortex flow piece 54. And is sent out to the swivel tube 52.
[0044]
The exhaust gas G2 sent to the swirl tube 52 is separated into the high temperature gas G3 on the outer peripheral side and the low temperature gas G4 on the center side by the vortex effect described above, and reaches the flow rate adjusting valve unit 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.
[0045]
The hot gas G3 that has reached the flow rate adjusting valve portion 53 is discharged from between the valve body 53b and the valve case 53a via the hot gas outlet 53c, and enters the hot gas inlet 3c of the filter 3 via the reflux passage 6. The filter 3 is heated.
[0046]
The flow rate of the high-temperature gas G3 is adjusted by the valve opening degree of the flow rate adjusting valve unit 53, but this flow rate is closely related to the temperature of the high-temperature gas, so that the filter 3 can be heated most efficiently. In addition, the valve opening degree is adjusted and controlled.
[0047]
On the other hand, the low temperature gas G3 that has reached the flow rate adjusting valve portion 53 bounces off at the valve body 53b, passes through a pipe-shaped portion having a low central pressure, passes through the low temperature gas discharge passage 54b of the vortex flow piece 54, and passes through the low temperature gas outlet 54c. Is discharged to the exhaust passage 7 and goes out.
[0048]
Accordingly, 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 the high temperature gas G3 and the low temperature gas G4 using the vortex effect, and the separated high temperature gas G3 can be refluxed to the filter 3 to heat the filter 3. .
[0049]
Moreover, since the high temperature gas G3 reintroduced into the filter 3 raises the temperature inside the filter 3, the internal temperature of the filter 3 can be raised to 600 ° C. or more, which is the particulate combustion temperature, by repeating this. it can.
[0050]
When the particulate combustion temperature is reached, the particulates start to burn, so the particulates collected in the filter 3 are combusted and discharged as gas, and the inside of the filter 3 is washed. .
[0051]
Even during the combustion of the particulates, the generation of the hot gas G3 and the reflux to the filter 3 can be continued without interruption, so that the collected particulates can be sequentially burned and removed, so that the filter 3 collects the particulates. Can prevent clogging.
[0052]
That is, the exhaust gas G2 that has passed through the filter 3 is separated into a high-temperature gas G3 and a low-temperature gas G4 using the vortex effect, and the separated high-temperature gas G3 is returned to the filter 3 to heat the filter 3, By heating, the temperature of the filter 3 can be heated above the combustion temperature of the particulates, and the particulates collected by the filter 3 can be removed by combustion.
[0053]
【The invention's effect】
As described above, according to the filter heating and regeneration method of a DPF device and the DPF device according to the present invention, the following effects can be obtained.
[0054]
By applying the vortex effect that has been demonstrated thermodynamically, the hot and cold gases are generated and separated from the exhaust gas, and the heat of the hot gas is used to heat the filter and burn the particulates deposited in the filter. Can be used.
[0055]
Since the DPF device that can use this vortex effect does not require a filter regeneration heater or an external power source for the heater, the cost can be reduced.
[0056]
In addition, since this DPF device has almost no movable parts and electrical parts, the failure rate is very low. Further, it is only disposed in the middle of the exhaust pipe, and it is not necessary to additionally install other parts such as a generator.
[0057]
In addition, the filter heating method and the filter regeneration method of the DPF device according to the present invention perform intermittent regeneration of the continuous regeneration type DPF that always regenerates the filter after particulate clogging becomes large. It can also be applied to the DPF of the formula.
[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 generating means of FIG.
[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 Swivel tube 53 Flow rate adjusting valve part 53a Valve case 53b Valve body 53c Hot gas outlet 54 Swirl piece (vortex generating member)
54a Swivel hole 54b Low temperature gas discharge passage 54c Low temperature gas outlet

Claims (5)

A method of heating a filter that collects particulates in exhaust gas in an exhaust passage of an internal combustion engine, wherein the exhaust gas that has passed through the filter is separated into high-temperature gas and low-temperature gas using a vortex effect, A filter heating method for a DPF device, wherein the separated hot gas is refluxed to the filter to heat the filter. A method of regenerating a filter that collects particulates in exhaust gas in an exhaust passage of an internal combustion engine, wherein the exhaust gas that has passed through the filter is separated into high-temperature gas and low-temperature gas using a vortex effect, The separated high-temperature gas is refluxed to the filter to heat the filter, and by the heating, the temperature of the filter is heated to a particulate combustion temperature or more, and the particulates collected in the filter are burned and removed. A filter regeneration method for a DPF device. A DPF device having 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,
Using the vortex effect generating means for separating the exhaust gas that has passed through the filter into a high temperature gas and a low temperature gas using the vortex effect, and the high temperature gas separated by the vortex effect generating means A DPF device comprising heating means for heating the filter. 4. The DPF device according to claim 3, wherein the heating means is a recirculation passage for recirculating the high temperature gas generated by the vortex effect generating means to the upstream side of the filter. The vortex effect generating means includes an expansion swirling portion having an exhaust gas inlet and a low temperature gas outlet, a swirling tube connected to the expansion swirling portion, a flow rate adjustment having a hot gas outlet connected to the other end of the swirling tube Formed from the valve part,
The expansion swirl is formed by an expansion chamber that adiabatically expands exhaust gas introduced from an exhaust gas inlet, and a vortex generator that is disposed inside the expansion chamber.
The eddy current generating member is formed to have a swirl hole that is provided to penetrate the exhaust gas from the center side to the outer periphery side in a high-speed swirl flow, and a low-temperature gas discharge passage that is provided on the center side. And
The flow rate adjusting valve part is a valve for adjusting a flow rate at which the high temperature gas on the outer peripheral side in the swivel tube is discharged from the high temperature gas outlet, a valve case, and a valve body inserted in the valve case, 5. The DPF device according to claim 3, wherein the DPF device is formed by a valve actuator that drives the valve body to adjust a valve opening degree.

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