US20150089924A1

US20150089924A1 - Exhaust gas processing device, exhaust gas processing system, method for controlling exhaust gas processing system, control program, and cylindrical tube

Info

Publication number: US20150089924A1
Application number: US14/388,558
Authority: US
Inventors: Unryu Ogawa; Kotaro Takenaga; Katsumi Takahashi
Original assignee: Hitachi Kokusai Electric Inc
Current assignee: Hitachi Kokusai Electric Inc
Priority date: 2012-04-26
Filing date: 2013-03-14
Publication date: 2015-04-02
Also published as: WO2013161423A1; JPWO2013161423A1; CN104220709A

Abstract

An exhaust gas processing system includes a cylindrical tube through which an exhaust gas of an engine passes, a sensor configured to detect information regarding the exhaust gas discharged from the engine, a coil antenna provided on an outer periphery of the cylindrical tube and connected to a high-frequency power supply, and a control unit configured to control output power of the high-frequency power supply. The control unit controls output power of the high-frequency power supply based on the information detected by the sensor.

Description

TECHNICAL FIELD

The present invention relates to an exhaust gas processing device for purifying an exhaust gas discharged from an engine, an exhaust gas processing system, a method for controlling the exhaust gas processing system, a control program, and a cylindrical tube.

BACKGROUND ART

In a diesel engine, it is known that, due to a structural problem, a nitrogen oxide (NOx) and particulate matter (PM) are contained in an exhaust gas.
As a method for reducing emission of a NOx, there is known an urea SCR (Selective Catalytic Reduction) system. In the urea SCR system, urea water (ammonia, NH₃) is sprayed on the NOx. By the reaction of the urea water, the NOx is reduced into nitrogen (N₂) and water (H₂O), thereby reducing the emission amount of the NOx.
As a method for reducing PM, there is known a diesel particulate filter (DPF) system. The DPF system is composed of a porous filter having a catalyst. The DPF system reduces the emission amount of PM by collecting the PM with the filter when an exhaust gas passes therethrough.
However, in the urea SCR system, a constant amount of urea water needs to be maintained in order to keep purification performance high. Furthermore, in the DPF system, it is necessary to periodically clean the filter. Thus, the conventional exhaust gas processing systems require periodic maintenance.
In addition, with a view to reducing a NOx and PM, a purification device that makes use of barrier discharge plasma is under review. The barrier discharge plasma is generated by, e.g., covering one or both electrodes of spaced-apart flat plates with an insulating material and applying an alternating current voltage thereto. However, the plasma generated by barrier discharge is locally instable. Therefore, even if an exhaust gas flows between the plasma-generating electrodes, it is difficult to convert the exhaust gas to uniform plasma. This makes it difficult to obtain high purification performance. Patent Document 1 discloses a purification device that makes use of barrier discharge plasma.
Patent Document 1: Japanese Patent Application Publication No. 2006-170049
As mentioned above, it is difficult in the urea SCR system and the DPF system to keep purification performance high without maintenance. Moreover, it is difficult in the barrier discharge plasma method to obtain stable and high purification performance.
As other plasma generating methods, it is conceivable to employ a capacity coupling method represented by parallel flat plate electrodes and a microwave method in which a gas is plasma-excited by irradiating microwaves to the gas. These methods are hard to generate stable plasma in an atmosphere other than a vacuum atmosphere and are not suitable for processing an engine exhaust gas.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an exhaust gas processing device capable of maintaining stable and high purification performance, an exhaust gas processing system, a method for controlling the exhaust gas processing system, a control program, and a cylindrical tube.
In accordance with a first aspect of the present invention, there is provided an exhaust gas processing device, including: a cylindrical tube through which an exhaust gas discharged from an engine passes; and a coil antenna provided on an outer periphery of the cylindrical tube and connected to a high-frequency power supply.
In accordance with a second aspect of the present invention, there is provided an exhaust gas processing system, including: a cylindrical tube through which an exhaust gas discharged from an engine passes; a high-frequency power supply; a coil antenna provided on an outer periphery of the cylindrical tube and connected to the high-frequency power supply; a sensor configured to detect information regarding the exhaust gas discharged from the engine; and a control unit configured to control an output power of the high-frequency power supply based on the detected information.
In accordance with a third aspect of the present invention, there is provided a method for controlling an exhaust gas processing system which includes a cylindrical tube through which an exhaust gas discharged from an engine passes, a high-frequency power supply, a coil antenna provided on an outer periphery of the cylindrical tube and connected to the high-frequency power supply, a sensor configured to detect information regarding the exhaust gas discharged from the engine, and a control unit, the method including: a step in which the sensor detects the information regarding the exhaust gas discharged from the engine; and a step in which the control unit controls an output power of the high-frequency power supply based on the detected information.
In accordance with a fourth aspect of the present invention, there is provided a control program for an exhaust gas processing system which includes a cylindrical tube through which an exhaust gas discharged from an engine passes, a high-frequency power supply, a coil antenna provided on an outer periphery of the cylindrical tube and connected to the high-frequency power supply, a sensor configured to detect information regarding the exhaust gas discharged from the engine, and a control unit, wherein the control program executes: a step in which the sensor detects the information regarding the exhaust gas discharged from the engine; and a step in which the control unit controls an output power of the high-frequency power supply based on the detected information.
In accordance with a fifth aspect of the present invention, there is provided a cylindrical tube around which a coil antenna is wound, the cylindrical tube including: an exhaust gas path through which an exhaust gas of an engine passes; and a coolant flow path provided at an outer periphery of the exhaust gas path.

ADVANTAGEOUS EFFECTS OF THE INVENTION

According to the present invention, it is possible to provide an exhaust gas processing device capable of maintaining stable and high purification performance, an exhaust gas processing system, a method for controlling the exhaust gas processing system, a control program, and a cylindrical tube.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing a configuration of an exhaust gas processing system according to an embodiment of the present invention.

FIG. 2 is a schematic diagram illustrating a control unit according to the embodiment of the present invention.

FIG. 3 is a schematic diagram illustrating a sensor according to the embodiment of the present invention.

FIGS. 4A and 4B are views showing an exhaust gas processing device according to the embodiment of the present invention.

MODE FOR CARRYING OUT THE INVENTION

An exhaust gas processing system 100 according to an embodiment of the present invention will be described with reference to FIG. 1. FIG. 1 is an explanatory view schematically illustrating the exhaust gas processing system.
The exhaust gas processing system 100 according to the embodiment of the present invention is connected to an engine 101 mounted to a motor vehicle. In the present embodiment, it is assumed that the engine 101 is a diesel engine. The engine 101 emits an exhaust gas containing a NOx and PM during its operation.
An exhaust gas processing device 103 for purifying an exhaust gas is connected to the downstream side of the engine 101 through a first pipe 102. An exhaust port 106 is provided at the downstream side of the exhaust gas processing device 103, i.e., at the downstream side of the first pipe 102, through a second pipe 104 and a DPF 105. In other words, the exhaust gas processing device 103 is provided between the first pipe 102 and the second pipe 104. Details of the exhaust gas processing device 103 will be described later.
The exhaust gas processing system 100 includes an exhaust gas processing device 103, a control unit 107 and a sensor 108. The control unit 107 receives information detected by the sensor 108 and controls the exhaust gas processing device 103 based on the information. As shown in FIG. 2, the control unit 107 includes a memory 202 which stores a program for controlling the exhaust gas processing device 103. Furthermore, the memory 202 has a function of storing data received from the sensor 108. A CPU (Central Processing Unit) 201 is provided within the control unit 107. The CPU 201 controls the exhaust gas processing device 103 pursuant to the data received from the sensor 108 and the program stored within the memory 202.
The program may be configured to be rewritable and may be changed depending on the operation state of the engine 101 or the motor vehicle, the external environment, and the like. In addition, when upgrading a version of software or initializing a control operation, the program may be renewed through the use of a terminal such as a personal computer or the like. The control unit 107 may be either a control unit of the motor vehicle or a control unit dedicated to the exhaust gas processing system.
Next, details of the sensor 108 will be described with reference to FIG. 3. The sensor 108 detects different kinds of information of the motor vehicle, particularly the information on an exhaust gas discharged from the engine 101. The sensor 108 includes the following sensors. That is to say, the sensor 108 includes an air intake amount sensor 301 for detecting an intake amount of an air drawn into the engine 101, a temperature detecting sensor 302 for detecting a temperature of a cylindrical structure 401 employed in the exhaust gas processing device 103, a NOx concentration detecting sensor 303 for detecting a NOx concentration (or amount) of an exhaust gas discharged from the engine 101, and a PM concentration detecting sensor 304 for detecting a PM concentration (or amount) in an exhaust gas discharged from the engine 101. The data detected by the sensor 108 are stored in the memory 202 of the control unit 107. The respective sensors may be the ones mounted to the motor vehicle in advance or may be newly mounted.
Next, the exhaust gas processing device 103 will be described with reference to FIGS. 4A and 4B. FIG. 4A is a schematic diagram of the exhaust gas processing device and FIG. 4B is a sectional view taken along line (A)-(A′) in FIG. 4A. In FIG. 4B, for the sake of convenience in description, a coil 411 to be described later is omitted.
The exhaust gas processing device 103 includes a cylindrical tube 401 made of quartz. As shown in FIG. 4B, the cylindrical tube 401 includes an exhaust gas path 403 through which an exhaust gas of the engine 101 passes and a coolant flow path 405 provided on the outer periphery of the exhaust gas path 403. More specifically, the cylindrical tube 401 is mainly composed of the exhaust gas path 403 surrounded by an inner wall 402 and the coolant flow path 405 as a temperature control unit provided between the inner wall 402 and an outer wall 404. The coolant flow path 405 is formed on the surface opposite to a coil 411 to be described later.
In the coolant flow path 405, there are provided a coolant supply port 406 for supplying a coolant therethrough and a coolant discharge port 407 for discharging a coolant therethrough. A coolant 420 is supplied to the coolant flow path 405 through the coolant supply port 406. The coolant 420 supplied to the coolant flow path 405 is discharged through the coolant discharge port 407. The coolant discharge port 407 is connected to a below-described coolant supply source through a pipe (not shown).
As shown in FIG. 4A, the coolant 420 is supplied from a coolant supply source (e.g., an electric pump) 421 to the coolant supply port 406 through a coolant supply pipe 422. The coolant supply source 421, a flow rate control unit (mass flow controller) 423 and a valve 424 are provided in the coolant supply pipe 422 in that order from the upstream side. The control unit 107 controls the flow rate control unit 423 and the valve 424, thereby controlling the supply amount of the coolant supplied to the coolant supply port 406. A cooling medium represented by Galden is used as the coolant 420.
In the present embodiment, the coolant flow path 405, the coolant supply port 406 and the coolant discharge port 407 are collectively referred to as a temperature control unit. However, one or all of the coolant supply source 421, the coolant supply pipe 422, the flow rate control unit 423 and the valve 424 may be included in the temperature control unit.
The inside of the cylindrical tube 401, i.e., the exhaust gas path 403, is formed into a circular columnar shape by the inner wall 402. Thus, the resistance on the contact surface of the inner wall 402 with an exhaust gas 430 is made uniform, thereby preventing the exhaust gas 430 from staying within the exhaust gas path 403. This restrains the NOx and the PM contained in the exhaust gas 430 from remaining within the exhaust gas path 403.
The exhaust gas path 403 is configured to bring the first pipe 102 and the second pipe 104 into communication with each other. This makes it possible to reliably supply the exhaust gas 430 from the engine 101 to the exhaust gas processing device 103. Furthermore, it is possible to reliably supply the gas purified in the exhaust gas processing device 103 to the exhaust port 106 through the second pipe 104.
The coil (coil antenna) 411 connected to a high-frequency power supply 412 is provided on the outer periphery of the outer wall 404 of the cylindrical tube 401. In other words, the coil 411 is provided so as to surround the outer wall 404 at the side surface (outer periphery) of the cylindrical tube 401. The high-frequency power supply 412 is connected to the control unit 107 and a battery (not shown) mounted to the motor vehicle. The high-frequency power supply 412 converts a direct current supplied from the battery to a specified high frequency power. The high-frequency power supply 412 amplifies and outputs the high frequency power. The high-frequency power supply 412 includes a variable amplifier and can adjust output power. When the exhaust gas 430 is flowing through the exhaust gas path 403, the control unit 107 controls the high-frequency power supply 412 to apply a high frequency power to the coil 411. So-called inductively coupled plasma is generated by this structure. The inductively coupled plasma can be stably generated even under an atmospheric pressure. Thus, it is possible to generate stable plasma even in a driving motor vehicle.
A high voltage is applied to the exhaust gas 430 by the coil 411 applied with a high frequency power, whereby the exhaust gas 430 is converted to a plasma state. An eddy current is generated within the plasma by the varying magnetic fields of the high frequency power. As a result, Joule heat is generated. In this way, exhaust gas plasma of a high temperature state is generated in the exhaust gas path 403. A NOx contained in the exhaust gas of a plasma state is decomposed into N (nitrogen) and O (oxygen) and is recombined with oxygen and nitrogen as given by the following formula (1).
2NOx→xO₂+N₂ (1)
The nitrogen and the oxygen thus decomposed are discharged through the exhaust port 106. On the other hand, the PM contained in the exhaust gas 430 is burned by the plasma of a high temperature state. In this way, the exhaust gas 430 is purified.
On the surface of the outer wall 404 of the cylindrical tube 401, a cylindrical temperature sensor 302 is provided in a region that receives the magnetic fields of the coil 411. As described earlier, upon generating the plasma, an eddy current is generated by the magnetic fields of the coil 411. As a result, Joule heat is generated. Thus, the region affected by the magnetic fields of the coil 411 has a highest temperature. For that reason, the coolant flow path 405 is provided on the surface opposite to the coil 411.
Thus, the cylindrical temperature sensor 302 for determining whether the temperature of the inside of the cylindrical tube is suitably controlled by the coolant flow path 405 is provided on the outer wall 404. More specifically, the cylindrical temperature sensor 302 is provided between coil end portions 411 a and 411 b of the coil 411. In this regard, the coil end portions 411 a and 411 b refer to those portions separating from the outer wall 404 of the cylindrical tube 401. By detecting the temperature of the outer wall 404 with the cylindrical temperature sensor 302, it is possible to indirectly detect the temperature of the exhaust gas path 403, i.e., the temperature of the exhaust gas 403. Alternatively, the cylindrical temperature sensor 302 may be provided in the exhaust gas path 403 or on the inner wall 402 to directly detect the temperature of the exhaust gas 430.
It is known that, if the mixing atmosphere of N and O is 550° C. or higher, N and O are recombined with each other. Accordingly, if the temperature of the exhaust gas 430 passing through the cylindrical tube 401 becomes 550° C. or higher, there is a fear that the decomposed N and O are recombined with each other and are returned to the NOx again. In the meantime, it is known that PM is burned at 350° C. or higher.
Thus, in the present embodiment, the temperature of the exhaust gas 430 is preferably controlled to be 350° C. or higher and lower than 550° C. Depending on the concentration of a NOx or PM contained in the exhaust gas 430, the temperature of the exhaust gas 430 may be controlled to be 350° C. or higher and 650° C. or lower.
Based on the temperature information detected by the cylindrical temperature sensor 302, the control unit 107 controls the flow rate control unit 423 and the valve 424 to thereby control the supply amount of the coolant supplied to the coolant supply port 406, whereby the temperature of the exhaust gas 430 is controlled to fall within the aforementioned range.
Subsequently, description will be made on a method for purifying an exhaust gas through the use of the present exhaust gas processing system. The following operations are controlled by the control unit of the motor vehicle or the control unit 107. Here, description will be made on the assumption that the following operations are mainly controlled by the control unit 107.
<Engine Startup Step>
Responsive to the instruction of a user of the motor vehicle, the control unit of the motor vehicle starts up the engine 101.
<Plasma Excitation Step>
If the engine 101 is started up, the control unit 107 feeds electric power to the coil 411 and applies a high frequency power. Thus, the exhaust gas 430 supplied to the exhaust gas path 403 is excited into a plasma state. The feeding of electric power to the coil 411 may be started prior to the startup of the engine 101 (e.g., at the time at which an ignition switch is moved to a specified position).
<Supply Power Adjustment Step>
If plasma is excited, the air intake amount sensor 301 detects the amount of an air drawn into the engine 101. The detected information is first stored in the memory 202 of the control unit 107.
Since the air intake amount and the exhaust gas amount are in a proportional relationship with each other, the exhaust gas amount can be calculated by detecting the air intake amount with the air intake amount sensor 301. The control unit 107 decides the output power of the high-frequency power supply 412 based on the exhaust gas amount thus calculated.
The high frequency power may be calculated by taking into account not only the detection value of the air intake amount sensor 301 but also the detection value of the NOx concentration detecting sensor 303 or the PM concentration detecting sensor 304 and other operation conditions of the engine 101 or the motor vehicle (such as a fuel injection amount, an air-fuel ratio, a speed, an acceleration (load), an engine speed, and the like). Instead of detecting the air intake amount, it may be possible to detect a throttle opening degree or a flow rate of the exhaust gas.
That is to say, the sensor 108 is not limited to the sensors shown in FIG. 3, as long as the sensor 108 can detect the information on the exhaust gas discharged from the engine 101. The control unit 107 decides the output power of the high-frequency power supply 412 based on the information (one kind of information or a combination of different kinds of information) detected by the sensor 108.
Next, based on the detection values stored in the memory 202, the CPU 201 of the control unit 107 decides the high frequency power to be applied to the coil 411. The start of the supply power adjustment step is not limited to the plasma excitation time. The supply power adjustment step may be performed at an appropriate timing before or after the feeding of electric power to the coil 411.
In an inductively coupled plasma (ICP) method, it is known that the electric power applied to a coil and the electron density of plasma are proportional to each other. Thus, in the present embodiment, the output power of the high-frequency power supply 412 is controlled depending on the air intake amount, i.e., the amount of the exhaust gas 430. By doing so, even if the amount of the exhaust gas 430 is increased, it is possible to generate plasma at a high density. That is to say, it is possible to efficiently decompose the exhaust gas 430.
In case of the present step, if the amount of the exhaust gas 430 is determined to be large, the output power of the high-frequency power supply corresponding thereto is calculated and is applied to the coil. Specifically, the output power of the high-frequency power supply 412 is increased as the amount of the exhaust gas becomes larger.
An appropriate relationship between the air intake amount (the exhaust gas amount) and the high frequency power is derived in advance through experiments. The output power of the high-frequency power supply 412 is controlled based on the appropriate relationship. The appropriate relationship refers to a relationship in which the exhaust gas is efficiently decomposed. If the air intake amount (the exhaust gas amount) has an appropriate relationship with the current high frequency power, the power supply level is maintained. Since the high frequency power is applied depending on the amount of the exhaust gas, it is possible to efficiently decompose the exhaust gas at all times.
<Coolant Supply Step>
By controlling the flow rate control unit 423 and the valve 424, the coolant is supplied to the coolant flow path 405 through the coolant supply port 406. In this way, the plasma of the exhaust gas 430 is maintained in a predetermined temperature range. More specifically, the temperature of plasma of the exhaust gas 430 is controlled to become 350′C or higher, at which PM is burned, and 5500 or lower, which is lower than the recombination temperature of a NOx.
Next, the temperature sensor 302 detects a temperature of the exhaust gas 430 (the outer wall 404 of the cylindrical tube 401, i.e., the wall of a plasma decomposition unit). Determination is made whether the temperature value is equal to or smaller than a predetermined value. If the temperature value is not equal to or smaller than the predetermined value, i.e., if the temperature value larger than the predetermined value is detected, the flow rate control unit 423 and the valve 424 are controlled to increase the supply amount of the coolant, thereby reducing the temperature of the exhaust gas 430.
If the detected temperature is equal to or smaller than the predetermined value, the supply amount of the coolant is maintained.
In this way, the temperature of the exhaust gas 430 is maintained at a temperature at which the PM is burned and at which the decomposed N and O are not recombined with each other. It is therefore possible to reduce the amount of the NOx and the PM.
Thereafter, if the engine 101 is stopped pursuant to the instruction of a user, the power supply to the coil 411 and the supply of the coolant are stopped.
As described above, according to the present embodiment, it is possible to provide an exhaust gas processing device capable of maintaining stable and high purification performance with respect to a discharged exhaust gas. Furthermore, the electric power and the coolant amount are adjusted depending on the situation of a motor vehicle. It is therefore possible to efficiently manage the electric power. Accordingly, the present exhaust gas processing device is particularly useful in, e.g., a motor vehicle having a limited battery capacity.
In the aforementioned embodiment, the present invention has been described using the quartz-made cylindrical tube. However, the present invention is not limited thereto. The cylindrical tube may be made of any material that allows electric fields to pass therethrough and that can endure a high temperature. For example, the cylindrical tube may be made of ceramic or carbon.
In the aforementioned embodiment, the electric power fed to the coil is controlled depending on the air intake amount. However, the present invention is not limited thereto. The electric power fed to the coil may be controlled depending on the concentration or the temperature of the exhaust gas or the engine load information such as the acceleration or the like. However, in the present embodiment, it is preferable to accurately measure the amount of the exhaust gas and to control the electric power depending on the measured value. It is more preferable to control the electric power depending on the information such as the air intake amount or the like, which has a proportional relationship with the exhaust gas amount.
In the aforementioned embodiment, a diesel engine has been described as the engine 101. However, the engine 101 may be a gasoline engine or an engine that uses an LP (liquefied petroleum) gas or the like as fuel. Furthermore, the engine 101 is mounted to the motor vehicle. However, the present invention is not limited thereto. The engine 101 may be used as a power source in a ship, a construction machine, a generator or the like rather than the motor vehicle. Moreover, the engine 101 or the DPF 105 may be used as a port of the exhaust gas processing system 100, thereby providing an integrated exhaust gas purification processing system that encompasses the control of the engine 101 and the collection of the PM in the DPF 105.
Next, other preferred embodiments of the present invention will be supplementarily stated. It goes without saying that the present invention is not limited to the following supplementary notes.
<Supplementary Note 1>
An exhaust gas processing device, including: a cylindrical tube through which an exhaust gas of an engine passes; and a coil antenna provided on an outer periphery of the cylindrical tube and connected to a high-frequency power supply.
This makes it possible to provide an exhaust gas processing device capable of maintaining stable and high purification performance.
<Supplementary Note 2>
The device of Supplementary Note 1, wherein a temperature control unit configured to control a temperature of an internal atmosphere of the cylindrical tube is provided to the cylindrical tube.
This makes it possible to maintain the exhaust gas at a temperature at which PM is burned and at which decomposed N and O are not recombined with each other. It is therefore possible to reduce the amount of a NOx and PM.
<Supplementary Note 3>
The device of Supplementary Note 2, wherein the exhaust gas contains at least particulate matter and a NOx and wherein the temperature control unit controls a temperature of the exhaust gas within the cylindrical tube to be 350° C. or higher and 650° C. or lower.
This makes it possible to reliably maintain the exhaust gas at a temperature at which a PM is burned and at which decomposed N and O are not recombined with each other. It is therefore possible to reliably reduce the amount of a NOx and PM.
<Supplementary Note 4>
The device of any one of Supplementary Notes 1 to 3, wherein a first pipe is connected to an upstream side of the cylindrical tube and a second pipe is connected to a downstream side of the cylindrical tube, the first pipe communicating with the second pipe.
This makes it possible to reliably supply the exhaust gas from the engine to the exhaust gas processing device and to reliably supply the gas purified in the exhaust gas processing device to an exhaust port through the second pipe.
<Supplementary Note 5>
The device of any one of Supplementary Notes 1 to 4, further including: a control unit configured to control output power of the high-frequency power supply based on information regarding the exhaust gas discharged from the engine.
This makes it possible to control the exhaust gas processing based on the information regarding the exhaust gas discharged from the engine. It is therefore possible to provide an exhaust gas processing system capable of being efficiently managed and capable of maintaining stable and high purification performance.
<Supplementary Note 6>
An exhaust gas processing system, including: a cylindrical tube through which an exhaust gas of an engine passes; a high-frequency power supply; a coil antenna provided on an outer periphery of the cylindrical tube and connected to the high-frequency power supply; a sensor configured to detect information regarding the exhaust gas discharged from the engine; and a control unit configured to control output power of the high-frequency power supply based on the detected information.
This makes it possible to control the exhaust gas processing based on the information regarding the exhaust gas discharged from the engine. It is therefore possible to provide an exhaust gas processing system capable of being efficiently managed and capable of maintaining stable and high purification performance.
<Supplementary Note 7>
A method for controlling an exhaust gas processing system which includes a cylindrical tube through which an exhaust gas of an engine passes, a high-frequency power supply, a coil antenna provided on an outer periphery of the cylindrical tube and connected to the high-frequency power supply, a sensor configured to detect information regarding the exhaust gas discharged from the engine, and a control unit, the method including: a step in which the sensor detects the information regarding the exhaust gas discharged from the engine; and a step in which the control unit controls output power of the high-frequency power supply based on the detected information.
This makes it possible to control the exhaust gas processing based on the information regarding the exhaust gas discharged from the engine. It is therefore possible to provide an exhaust gas processing system capable of being efficiently managed and capable of maintaining stable and high purification performance.
<Supplementary Note 8>
A control program for an exhaust gas processing system which includes a cylindrical tube through which an exhaust gas of an engine passes, a high-frequency power supply, a coil antenna provided on an outer periphery of the cylindrical tube and connected to the high-frequency power supply, a sensor configured to detect information regarding the exhaust gas discharged from the engine, and a control unit, wherein the control program executes a step in which the sensor detects the information regarding the exhaust gas discharged from the engine; and a step in which the control unit controls output power of the high-frequency power supply based on the detected information.
This makes it possible to control the exhaust gas processing based on the information regarding the exhaust gas discharged from the engine. It is therefore possible to provide a control program capable of being efficiently managed and capable of maintaining stable and high purification performance.
<Supplementary Note 9>
A cylindrical tube around which a coil antenna is wound, the cylindrical tube including: an exhaust gas path through which an exhaust gas of an engine passes; and a coolant flow path provided on an outer periphery of the exhaust gas path.
This makes it possible to provide a cylindrical tube for use in an exhaust gas processing device capable of maintaining stable and high purification performance.

EXPLANATION OF REFERENCE NUMERALS

- 100: exhaust gas processing system
- 103: exhaust gas processing device
- 107: control unit
- 108: sensor
- 401: cylindrical tube
- 403: exhaust gas path
- 405: coolant flow path
- 411: coil (coil antenna)
- 412: high-frequency power supply

Claims

1. An exhaust gas processing device, comprising:

a cylindrical tube through which an exhaust gas discharged from an engine passes; and

a coil antenna provided on an outer periphery of the cylindrical tube and connected to a high-frequency power supply.

2. The exhaust gas processing device of claim 1, wherein a temperature control unit configured to control a temperature of an internal atmosphere of the cylindrical tube is provided in the cylindrical tube.

3. The exhaust gas processing device of claim 2, wherein the exhaust gas contains at least particulate matter and a nitrogen oxide and wherein the temperature control unit controls a temperature of the exhaust gas within the cylindrical tube to be 350° C. or higher and 650° C. or lower.

4. The exhaust gas processing device of claim 1, wherein a first pipe is connected to an upstream side of the cylindrical tube and a second pipe is connected to a downstream side of the cylindrical tube, the first pipe communicating with the second pipe.

5. The exhaust gas processing device of claim 1, further comprising:

a control unit configured to control an output power of the high-frequency power supply based on information regarding the exhaust gas discharged from the engine.

6. An exhaust gas processing system, comprising:

a cylindrical tube through which an exhaust gas discharged from an engine passes;

a high-frequency power supply;

a coil antenna provided on an outer periphery of the cylindrical tube and connected to the high-frequency power supply;

a sensor configured to detect information regarding the exhaust gas discharged from the engine; and

a control unit configured to control an output power of the high-frequency power supply based on the detected information.

7. A method for controlling an exhaust gas processing system which includes a cylindrical tube through which an exhaust gas discharged from an engine passes, a high-frequency power supply, a coil antenna provided on an outer periphery of the cylindrical tube and connected to the high-frequency power supply, a sensor configured to detect information regarding the exhaust gas discharged from the engine, and a control unit, the method comprising:

detecting the information regarding the exhaust gas discharged from the engine with the sensor; and

controlling an output power of the high-frequency power supply based on the detected information by the control unit.

8. A control program for an exhaust gas processing system which includes a cylindrical tube through which an exhaust gas discharged from an engine passes, a high-frequency power supply, a coil antenna provided on an outer periphery of the cylindrical tube and connected to the high-frequency power supply, a sensor configured to detect information regarding the exhaust gas discharged from the engine, and a control unit, wherein the control program executes:

9. A cylindrical tube around which a coil antenna is wound, the cylindrical tube comprising:

an exhaust gas path through which an exhaust gas of an engine passes; and

a coolant flow path provided at an outer periphery of the exhaust gas path.

10. The exhaust gas processing device of claim 2, wherein a first pipe is connected to an upstream side of the cylindrical tube and a second pipe is connected to a downstream side of the cylindrical tube, the first pipe communicating with the second pipe.

11. The exhaust gas processing device of claim 3, wherein a first pipe is connected to an upstream side of the cylindrical tube and a second pipe is connected to a downstream side of the cylindrical tube, the first pipe communicating with the second pipe.

12. The exhaust gas processing device of claim 2, further comprising:

13. The exhaust gas processing device of claim 3, further comprising:

14. The exhaust gas processing device of claim 4, further comprising:

15. The exhaust gas processing device of claim 10, further comprising:

16. The exhaust gas processing device of claim 11, further comprising: