JP6459535B2 - Ozone supply device - Google Patents

Description

  The present invention relates to an ozone supply device that supplies ozone to an upstream side of a catalyst in an exhaust passage to oxidize predetermined components in the exhaust.

2. Description of the Related Art Conventionally, a combustion system including a catalyst that stores and purifies NOx (nitrogen oxide) in exhaust gas of an internal combustion engine is known. In such NOx occlusion reaction, NO ₂ (nitrogen dioxide) is more active than NO (nitrogen monoxide). Therefore, as described in Patent Documents 1 and 2, if the oxidation of NO with ozone is supplied to the exhaust passage to the NO ₂ by ozone supply device, it is possible to improve the storage efficiency. Further, even in a combustion system provided with a catalyst that oxidizes and purifies CO and HC in exhaust gas, if ozone is supplied to the exhaust passage, the oxidation function of the oxidation catalyst can be enhanced, which is useful.

  Note that the ozone supply device generally generates ozone from oxygen in the air by discharging the electrode into the air.

JP 2008-163887 A JP 2008-163898 A

  However, the present inventors actually connected the ozone supply device to the exhaust passage and conducted various tests, and found that “exhaust gas flows into the ozone supply device when exhaust pressure is high and soot adheres to the electrodes. It has been found that there is a problem of “disturbing the discharge”.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an ozone supply device that is intended to prevent foreign matter from adhering to an electrode due to exhaust gas flowing in.

  The invention disclosed herein employs the following technical means to achieve the above object. Note that the reference numerals in parentheses described in the claims and in this section indicate the correspondence with the specific means described in the embodiments described later, and do not limit the technical scope of the invention. .

A first disclosed invention is disposed in an exhaust passage (10ex) of an internal combustion engine (10) and is provided in a combustion system including a catalyst for purifying exhaust gas, and supplies ozone to the upstream side of the catalyst in the exhaust passage. In the ozone supply device that oxidizes predetermined components in the exhaust gas, the ozone generator (30) that has an electrode (31) that discharges into the air and generates ozone by the discharge, and the ozone generated by the ozonizer to the exhaust passage A supply pipe (26) that forms a supply passage (26a) to be supplied, an air pump (30p) that blows ozone into the supply passage, and a supply pipe that opens and closes by an electromagnetic force generated in energization. The electromagnetic on- off valve (26v1 ) that opens and closes, the first control means (41a) that controls the operation of the on-off valve, and the pressure in the exhaust passage after a predetermined time become higher than the predetermined pressure. Prediction means (S22, S100) for predicting whether or not, and air volume acquisition means (S31) for acquiring the amount of ozone blown by the air pump . When the first control means is in a high pressure state by the prediction means The on-off valve is operated to close when the predicted air flow rate acquired by the air flow rate acquisition means is smaller than a preset flow rate threshold value .
A second invention to be disclosed is disposed in an exhaust passage (10ex) of an internal combustion engine (10) and is provided in a combustion system including a catalyst for purifying exhaust gas, and supplies ozone to the upstream side of the catalyst in the exhaust passage. In the ozone supply device that oxidizes predetermined components in the exhaust gas, the ozone generator (30) that has an electrode (31) that discharges into the air and generates ozone by the discharge, and the ozone generated by the ozonizer to the exhaust passage A supply pipe (26) that forms a supply passage (26a), an electromagnetic on-off valve (26v1) that is provided in the supply pipe and opens and closes by an electromagnetic force generated by energization; First control means (41a) for controlling the operation of the valve, prediction means (S22, S100) for predicting whether or not the pressure in the exhaust passage after a predetermined time is higher than the predetermined pressure, Provided, the first control means is predicted to be a high-pressure state by the prediction means, and the pressure in the exhaust passage is higher than the exhaust pressure threshold value, characterized in that for valve closing the on-off valve.

According to the first and second aspects of the invention , when the exhaust pressure is high, the on-off valve is closed to suppress the exhaust from flowing backward into the supply passage and flowing into the ozone supply device. Therefore, it is possible to suppress foreign matters such as soot contained in the exhaust from adhering to the electrode, and it is possible to suppress discharge from being hindered by foreign matter adhesion.

The schematic diagram which shows the reducing system which has a function as an ozone supply apparatus which concerns on 1st Embodiment of this invention, and the combustion system to which this apparatus is applied. The flowchart which shows the process sequence of control based on the reducing agent supply apparatus shown in FIG. The flowchart which shows the procedure of the interruption process which controls an on-off valve in 1st Embodiment. The flowchart which shows the procedure of the interruption process which controls an on-off valve in 2nd Embodiment of this invention. The flowchart which shows the procedure of the interruption process which controls an on-off valve in 3rd Embodiment of this invention. The flowchart which shows the procedure of the interruption process which controls an on-off valve in 4th Embodiment of this invention. The flowchart which shows the procedure of the interruption process which controls an on-off valve in 5th Embodiment of this invention. The flowchart which shows the procedure of the interruption process which controls an on-off valve in 6th Embodiment of this invention. The schematic diagram which shows the ozone supply apparatus which concerns on 7th Embodiment of this invention. The schematic diagram which shows the ozone supply apparatus which concerns on 8th Embodiment of this invention. The flowchart which shows the procedure of the interruption process which controls an open valve in 8th Embodiment. The flowchart which shows the procedure of the interruption process which controls an open valve in 9th Embodiment of this invention. The schematic diagram which shows the ozone supply apparatus which concerns on 10th Embodiment of this invention.

  Hereinafter, a plurality of modes for carrying out the invention will be described with reference to the drawings. In each embodiment, portions corresponding to the matters described in the preceding embodiment may be denoted by the same reference numerals and redundant description may be omitted. In each embodiment, when only a part of the configuration is described, the other configurations described above can be applied to other portions of the configuration.

(First embodiment)
The combustion system shown in FIG. 1 includes an engine 10 (internal combustion engine), a supercharger 11, a NOx purification device 12, a particulate collection device (DPF 13), and a reducing agent addition device, which will be described in detail below. The combustion system is mounted on a vehicle, and the vehicle runs using the output of the engine 10 as a drive source. The engine 10 is a compression self-ignition type diesel engine, and light oil that is a hydrocarbon compound is used as a fuel for combustion. The engine 10 basically operates to burn in a lean state. That is, combustion is performed (lean combustion) in a state where the air-fuel ratio, which is the ratio between the fuel injected into the combustion chamber and the air sucked into the combustion chamber, is set to an excess of air.

  The supercharger 11 includes a turbine 11a, a rotating shaft 11b, and a compressor 11c. The turbine 11a is disposed in the exhaust passage 10ex of the engine 10 and rotates by the kinetic energy of the exhaust. The rotating shaft 11b couples the impellers of the turbine 11a and the compressor 11c to transmit the rotational force of the turbine 11a to the compressor 11c. The compressor 11 c is disposed in the intake passage 10 in of the engine 10 and compresses intake air to supercharge the engine 10.

  A cooler (not shown) for cooling the intake air (pressurized air) compressed by the compressor 11c is disposed on the downstream side of the compressor 11c in the intake passage 10in. The compressed intake air cooled by the cooler is adjusted in flow rate by a throttle valve (not shown) and distributed to a plurality of combustion chambers of the engine 10. A NOx purification device 12 is disposed downstream of the turbine 11a in the exhaust passage 10ex, and a DPF 13 (Diesel Particulate Filter) is disposed further downstream. The DPF 13 collects fine particles contained in the exhaust.

  A connecting pipe 23 of a reducing agent addition device is connected to the exhaust passage 10ex on the upstream side of the NOx purification device 12. The reformed fuel generated by the reducing agent addition device is added as a reducing agent from the connecting pipe 23 to the exhaust passage 10ex. The reformed fuel is obtained by partially oxidizing a hydrocarbon compound (fuel) used as a reducing agent and reforming it into a partially oxidized hydrocarbon such as an aldehyde. Moreover, the reducing agent addition device has a function of supplying ozone from the connection pipe 23 to the exhaust passage 10ex, and provides an ozone supply device.

The NOx purification device 12 is configured by accommodating a honeycomb-shaped carrier in a housing. A coating material is provided on the surface of the carrier, and a reduction catalyst is supported on the coating material. The NOx purification device 12 purifies NOx contained in the exhaust by reacting NOx in the exhaust with the reformed fuel on the reduction catalyst and reducing it to N ₂ . The exhaust gas contains O ₂ (oxygen) in addition to NOx, but the reformed fuel reacts selectively with NOx in the presence of O ₂ .

  A reduction catalyst having a function of adsorbing NOx is used. Specifically, when the catalyst temperature is lower than the activation temperature at which the reduction reaction is possible, the reduction catalyst exhibits a function of adsorbing NOx in the exhaust. For example, the NOx purification device 12 having a NOx adsorption function is provided by a reduction catalyst made of silver alumina supported on a carrier. Specifically, it is a structure in which silver as a reduction catalyst is supported on alumina coated on the support surface. The adsorbed NOx is desorbed from the reduction catalyst when the catalyst temperature is equal to or higher than the activation temperature. The desorbed NOx is reduced and purified by the reformed fuel. Furthermore, this reduction catalyst has a function of adsorbing active oxygen in addition to the NOx adsorption function.

  Next, a reducing agent addition device that generates reformed fuel and adds it to the exhaust passage 10ex from the connection pipe 23 will be described. The reducing agent addition apparatus includes a reaction vessel 20, a heater 21, an injection valve 22, an ozonizer 30, an air pump 30p, a connection pipe 23, a supply pipe 26, an on-off valve 26v1, and an electronic control unit (ECU 40) described in detail below.

  The ozonizer 30 includes a housing 32 that forms a flow passage 32a therein, and a plurality of electrodes 31 are disposed in the flow passage 32a. These electrodes 31 have a flat plate shape arranged so as to face each other in parallel, and electrodes to which a high voltage is applied and electrodes having a ground voltage are alternately arranged. The voltage application to the electrode 31 is controlled by a microcomputer (microcomputer 41) provided in the ECU 40.

  The air blown by the air pump 30p flows into the housing 32 of the ozonizer 30. The air pump 30p is a centrifugal air pump, and is configured by housing an impeller driven by an electric motor in a case. This electric motor is controlled by the microcomputer 41. For example, the amount of air blown by the air pump 30p is controlled by controlling the amount of power supplied by duty control. The air pump 30p sucks and pressurizes the air from the suction port 30in formed in the case, and blows air to the ozonizer 30. The air blown to the ozonizer 30 flows into the flow passage 32 a in the housing 32 and flows through the interelectrode passage 31 a that is a passage between the electrodes 31.

  The ozonizer 30 is connected to the reaction vessel 20 via the supply pipe 26. An electromagnetically driven on / off valve 26v1 is attached to the supply pipe 26. The on-off valve 26v1 is located on the upstream side of the reaction vessel 20. The opening / closing drive of the opening / closing valve 26v1 is controlled by the microcomputer 41. Specifically, the valve body of the on-off valve 26v1 is controlled to be switched between a fully open position and a fully closed position, and opens and closes the internal passage (supply passage 26a) of the supply pipe 26. Accordingly, when the air pump 30p is driven to open the on-off valve 26v1, the air that has flowed through the interelectrode passage 31a flows through the supply pipe 26, the reaction vessel 20, and the connection pipe 23 in order and flows into the exhaust passage 10ex. It will be. The microcomputer 41 when controlling the operation of the on-off valve 26v1 corresponds to the first control means 41a.

  A heater 21 and an injection valve 22 are attached to the reaction vessel 20, and a reaction chamber 20a communicating with the inflow port 20in and the outflow port 20out is formed inside the reaction vessel 20. The heater 21 has a heat generating portion that generates heat when energized, and power supply to the heat generating portion is controlled by the microcomputer 41. Specifically, the amount of heat generated is controlled by the microcomputer 41 performing duty control on the amount of power supplied to the heat generating unit. The heat generating portion is disposed in the reaction chamber 20a and heats the fuel injected from the injection valve 22 to the reaction chamber 20a. The temperature of the reaction chamber 20 a is detected by a reaction chamber temperature sensor 27. The reaction chamber temperature sensor 27 outputs the detected temperature information (reaction chamber temperature Th) to the ECU 40.

  The injection valve 22 has a body in which an injection hole is formed, an electric actuator, and a valve body. When the electric actuator is energized, the valve body opens and fuel is injected from the nozzle hole into the reaction chamber 20a. When the electric actuator is turned off, the valve body closes and fuel injection is stopped. The microcomputer 41 controls the amount of fuel injected per unit time into the reaction chamber 20a by controlling energization to the electric actuator. Liquid fuel in a fuel tank (not shown) is supplied to the injection valve 22 by a fuel pump (not shown). The fuel in the fuel tank is also used as the fuel for combustion described above, and the fuel used for combustion of the engine 10 and the fuel used as the reducing agent are shared.

  The fuel injected from the injection valve 22 into the reaction chamber 20a collides with the heat generating portion and is heated and vaporized. The vaporized fuel is mixed with the air flowing into the reaction chamber 20a from the inflow port 20in. As a result, the gaseous fuel is partially oxidized by oxygen in the air and reformed into partially oxidized hydrocarbons such as aldehydes. The reformed gaseous fuel (reformed fuel) flows into the exhaust passage 10ex through the connection pipe 23.

  When the electrode 31 of the ozonizer 30 is energized, electrons emitted from the electrode 31 collide with oxygen molecules contained in the air in the interelectrode passage 31a. Then, ozone is generated from oxygen molecules. That is, the ozonizer 30 generates ozone by changing oxygen molecules into a plasma state by discharge. Therefore, ozone is contained in the air flowing through the supply pipe 26 when the ozonizer 30 is energized.

  In the reaction chamber 20a, a cold flame reaction described in detail below occurs. This cold flame reaction is a reaction in which gaseous fuel is partially oxidized by oxygen in the air flowing in from the inlet 20in. Specific examples of such partially oxidized fuel (reformed fuel) include partial oxides (for example, aldehydes) in which a part of the fuel (hydrocarbon compound) is oxidized to aldehyde groups (CHO). It is done.

  The microcomputer 41 provided in the ECU 40 includes a storage device that stores a program, and a central processing unit that executes arithmetic processing according to the stored program. The ECU 40 controls the operation of the engine 10 based on various detection values such as the engine speed per unit time and the engine load.

  The engine speed is detected by a crank angle sensor 14 attached near the output shaft of the engine 10. Examples of the physical quantity representing the engine load include intake pressure, intake air amount, accelerator pedal depression amount, and the like. The intake pressure is detected by an intake pressure sensor 15 attached to a downstream portion of the compressor 11c in the intake passage 10in. The intake air amount is detected by an air flow meter 16 attached to the upstream side portion of the compressor 11c in the intake passage 10in. The accelerator pedal depression amount is detected by an accelerator sensor 17 attached to the accelerator pedal.

  Further, the ECU 40 is detected by the reaction chamber temperature sensor 27, the catalyst temperature sensor 42, the exhaust temperature sensor 43, the exhaust pressure sensor 44 and the air amount sensor 45 in addition to the detected values of the operating state of the engine 10 such as the engine speed and the engine load. Get the physical quantity. Based on these physical quantities, the operation of the reducing agent addition device is controlled. The catalyst temperature sensor 42 is attached to the NOx purification device 12 and detects the atmospheric temperature (catalyst temperature) of the reduction catalyst. The exhaust temperature sensor 43 is attached to the exhaust passage 10ex and detects the exhaust temperature. The exhaust pressure sensor 44 is attached to the exhaust passage 10ex and detects the exhaust pressure. The exhaust temperature sensor 43 and the exhaust pressure sensor 44 are attached to the upstream side of the NOx purification device 12 and the downstream side of the turbine 11a in the exhaust passage 10ex. The air amount sensor 45 is attached to the upstream side of the ozonizer 30 and the downstream side of the air pump 30p in the supply pipe 26, and detects the amount of air discharged from the air pump 30p.

  In general, the ECU 40 controls the operation of the reducing agent adding device as follows. That is, based on the reaction chamber temperature Th, switching is performed between a reducing agent supply control for supplying a reducing agent to the exhaust passage 10ex and an ozone supply control for supplying ozone. Further, when carrying out the reducing agent addition control, strong oxidation control, weak oxidation control, and oxidation stop control are switched based on the reaction chamber temperature Th.

  Specifically, the microcomputer 41 repeatedly executes the program of the procedure shown in FIG. 2 at a predetermined period, thereby controlling the operation of the reducing agent adding device. First, in step S10 of FIG. 2, it is determined whether or not the engine 10 is in operation. When it is determined that the engine is not in operation, it is assumed that NOx to be purified does not exist in the exhaust passage 10ex, and in step S19, full stop control is performed to stop the operation of the reducing agent addition device. The total stop control is control for stopping supply of the ozone and the reducing agent to the exhaust passage 10ex. That is, the air pump 30p, the ozonizer 30, the heater 21, and the injection valve 22 are all stopped, and the on-off valve 26v1 is closed.

  On the other hand, when it is determined in step S10 that the engine 10 is in operation, it is determined in step S11 whether or not the catalyst temperature is higher than a predetermined temperature T1. When it is determined that the temperature is lower than the predetermined temperature T1, it is determined in subsequent step S12 whether or not the catalyst temperature is higher than the second predetermined temperature T2. If it is determined that the temperature is lower than the second predetermined temperature, it is determined in subsequent step S13 whether or not the catalyst temperature is higher than the third predetermined temperature T3. If it is determined that the temperature is lower than the third predetermined temperature, it is determined in subsequent step S14 whether the catalyst temperature is higher than a fourth predetermined temperature T4 (predetermined temperature).

  The predetermined temperature T1 and the second predetermined temperature T2 are set to be higher than the third predetermined temperature T3. The predetermined temperature T1 is set to be higher than the second predetermined temperature T2. For example, when the third predetermined temperature T3 is 200 ° C., the second predetermined temperature T2 is set to 350 ° C., and the predetermined temperature T1 is set to 400 ° C. Here, the third predetermined temperature T3 of the reduction catalyst is the lowest temperature (activation temperature) at which NOx can be reduced and purified on the reduction catalyst. The fourth predetermined temperature T4 is the lowest temperature at which active oxygen can be adsorbed on the catalyst, and is set lower than the third predetermined temperature.

  If it is determined in steps S11, S12, S13, and S14 that the catalyst temperature is lower than the fourth predetermined temperature T4, the all-stop control described above is performed in step S19. When it is determined that the catalyst temperature is higher than the fourth predetermined temperature T4 and lower than the third predetermined temperature T3, ozone supply control is performed in step S15. When it is determined that the catalyst temperature is higher than the third predetermined temperature T3 and lower than the second predetermined temperature T2, strong oxidation control is performed in step S16. If it is determined that the catalyst temperature is higher than the second predetermined temperature T2 and lower than the predetermined temperature T1, weak oxidation control is performed in step S17. When it is determined that the catalyst temperature is higher than the predetermined temperature T1, oxidation stop control is performed in step S18.

  When the equivalent ratio, which is the ratio of the injected fuel to the supplied air, and the ambient temperature of the injected fuel are adjusted to a predetermined range, the injected fuel undergoes a cold flame reaction without reaching a hot flame reaction. The thermal flame reaction is a reaction in which carbon dioxide and water are produced by complete combustion of fuel. The cold flame reaction is a reaction in which fuel is partially oxidized by oxygen in the air. Specific examples of such partially oxidized fuel (reformed fuel) include partial oxides (for example, aldehydes) in which a part of the fuel (hydrocarbon compound) is oxidized to aldehyde groups (CHO). It is done. Based on this knowledge, in the strong oxidation control, weak oxidation control, and oxidation stop control according to steps S16, S17, and S18, the equivalent ratio and the ambient temperature are adjusted so that the reformed fuel is supplied to the catalyst.

  In the strong oxidation control according to step S16, the ozone generated by the ozonizer 30, the oxygen in the air, and the fuel vaporized by the heater 21 are mixed, and the fuel undergoes a cold flame reaction in the environment where ozone is present to cause partial oxidation. Is done.

  Specifically, the heater 21 is feedback-controlled so that the detection value (reaction chamber temperature Th) detected by the reaction chamber temperature sensor 27 coincides with a preset target temperature Ttrg. The target temperature Ttrg is set to be an ambient temperature (for example, 370 ° C.) at which the cold flame reaction is performed without reaching the hot flame reaction.

  Further, in the above strong oxidation control, when all of the NOx flowing into the NOx purification device 12 is reduced, the reducing agent addition amount for supplying the NOx purification device 12 without excess or deficiency is calculated as the target fuel amount Ftrg. For example, the target fuel amount Ftrg is set based on the NOx inflow amount flowing into the NOx purification device 12 per unit time and the catalyst temperature. The NOx inflow amount is estimated based on the operating state of the engine 10. The target fuel amount Ftrg is increased as the NOx inflow amount increases. Further, since the amount (reducing power) in which NOx is reduced on the reduction catalyst varies depending on the catalyst temperature, the target fuel amount Ftrg is set according to the difference in the reducing power depending on the catalyst temperature. Based on the calculated target fuel amount Ftrg, the operation of the injection valve 22 is controlled to perform fuel injection.

  Further, in the strong oxidation control, the target equivalent ratio φtrg is calculated so as to cause a cold flame reaction based on the reaction chamber temperature Th. Then, a target air amount Atrg is calculated based on the target equivalent ratio φtrg and the target fuel amount Ftrg, and the operation of the air pump 30p is controlled based on the target air amount Atrg. By controlling the reaction chamber temperature Th and the equivalence ratio as described above, a reformed fuel is generated by causing a cold flame reaction.

  Further, in the strong oxidation control, the opening / closing valve 26v1 is controlled to open, and the power supplied to the ozonizer 30 is controlled according to the concentration of fuel in the reaction vessel 20. Specifically, the target ozone amount Otrg is calculated based on the target fuel amount Ftrg. Specifically, the target ozone amount Otrg is calculated so that the ratio of the ozone concentration to the fuel concentration in the vaporizing chamber 25a becomes a predetermined value (for example, 0.2). For example, the ratio is set so that the cold flame reaction is completed within a predetermined time (for example, 0.02 seconds). Also, the target ozone amount Otrg is set to increase as the temperature of the reduction catalyst decreases.

  Then, based on the target air amount Atrg and the target ozone amount Otrg, a target energization amount Ptrg to the ozonizer 30 is calculated. Specifically, as the target air amount Atrg is larger, the residence time of air in the interelectrode passage 31a is shortened, so the target energization amount Ptrg is increased. Further, the target energization amount Ptrg is increased as the target ozone amount Otrg is increased. Next, the energization amount to the ozonizer 30 is controlled based on the target energization amount Ptrg. Specifically, as the target energization amount Ptrg is larger, the energization duty ratio to the ozonizer 30 is increased. Alternatively, the interval from the end of current energization to the start of next energization is shortened.

  By performing such a process, ozone is generated and supplied to the reaction vessel 20, so that the start timing of the cool flame reaction is advanced and the cool flame reaction time is shortened. Therefore, even if the reaction vessel 20 is downsized so that the residence time of the fuel in the reaction vessel 20 is shortened, the cold flame reaction can be completed within the residence time. Therefore, the reaction vessel 20 can be downsized.

  Thus, according to the strong oxidation control in step S16, the fuel is partially oxidized in an environment where ozone exists. On the other hand, in the weak oxidation control in step S17, the fuel is partially oxidized in an environment in which ozone does not exist by stopping the ozonizer 30 and stopping ozone generation. That is, heater control, fuel injection control, air pump control, and valve opening control are performed. However, discharge control is not performed, and the ozone generation is stopped by stopping energization to the ozonizer 30.

  According to the weak oxidation control in step S17, heating by heater control is performed to perform partial oxidation. On the other hand, in the oxidation stop control by step S18, the ozonizer 30 and the heater 21 are stopped, and ozone generation and fuel heating are stopped. As a result, fuel that is not partially oxidized without being oxidized by oxygen or ozone is added to the exhaust passage 10ex, and is exposed to high-temperature exhaust gas in the exhaust passage 10ex or the NOx purification device 12 to be partially oxidized. .

  In the oxidation stop control in step S18, fuel injection control, air pump control, and valve opening control are performed. However, the discharge control is not performed, the energization to the ozonizer 30 is stopped to stop the ozone generation, and the heater control is not performed to stop the energization to the heater 21 to stop the heating of the fuel.

In the ozone supply control according to step S19 in FIG. 2, the ozone generator 30 generally generates ozone in a state where the energization to the heater 21 is stopped and the energization to the injection valve 22 is stopped to stop the fuel injection. . The generated ozone is supplied to the exhaust passage 10ex through the supply pipe 26 and the connection pipe 23 by operating the air pump 30p with the on-off valve 26v1 opened. As a result, when the reduction catalyst of the NOx purification device 12 is not activated, NO in the exhaust is oxidized to NO ₂ by ozone, and the amount of NOx adsorbed on the reduction catalyst increases.

  In the ozone supply control, the ECU 40 acquires the operating state of the engine 10. The operating state includes the engine load, the engine speed, and the exhaust temperature Tex. The ECU 40 calculates the exhaust amount per unit time and the NO concentration in the exhaust based on the operating state, and estimates the NO amount flowing into the NOx purification device 12 per unit time from these values. Based on the NO amount estimated in this way, the ECU 40 calculates the ozone amount necessary for oxidizing NO (predetermined component) in the exhaust gas as the target ozone amount Otrg. Then, the supply power to the ozonizer 30 and the amount of air blown by the air pump 30p are controlled so that ozone of the target ozone amount Otrg (necessary amount) is supplied.

  In contrast to the present embodiment, if the heater 21 is energized during ozone supply control, the ozone is heated and collapses. Moreover, if fuel injection is implemented, ozone will react with fuel. In this embodiment in view of these points, since heating by the heater 21 is stopped and fuel injection is stopped, it is possible to avoid ozone reacting with fuel and heating collapse. Therefore, the generated ozone is added to the exhaust passage 10ex as it is.

  FIG. 3 is a process that is repeatedly executed by the microcomputer 41 at a predetermined cycle when the engine 10 is in operation, and is a process for forcibly closing the on-off valve 26v1. The process of FIG. 3 is an interrupt process that is performed in preference to the process of FIG. For example, according to the processing of steps S15, S16, S17, and S18 in FIG. 2, the on-off valve 26v1 is controlled to open. However, when the valve closing control of the on-off valve 26v1 is performed by the processing of FIG. 3, the valve closing control by the processing of FIG. 3 is performed in preference to the valve opening control by the processing of FIG.

  First, in step S20 of FIG. 3, the engine load is acquired, and in subsequent step S21, the engine speed is acquired. In the subsequent step S22, the exhaust pressure (exhaust pressure reached value) after a predetermined time is predicted. For example, when the values of the engine load and the engine speed acquired in steps S20 and S21 are rapidly increasing, there is a high probability that the exhaust pressure reaching value is also rapidly increasing. Therefore, the exhaust pressure reached value is predicted based on the degree of change in engine load and engine speed.

  In subsequent step S100, it is determined whether or not the predicted exhaust pressure predicted in step S22 is higher than a predetermined pressure. The predetermined pressure used for this determination is set to the air pump limit pressure. The air pump limit pressure is the air discharge pressure of the air pump 30p when the air pump 30p is operated at the maximum output. When it is determined that the predicted exhaust pressure value> the air pump limit pressure, it is considered that the exhaust pressure becomes higher than the air pump limit pressure after a predetermined time, and in the subsequent step S200, the on-off valve 26v1 is forcibly closed. When it is not determined that the predicted exhaust pressure value> the air pump limit pressure, the process returns to step S20 without forcibly closing the on-off valve 26v1. Thus, the microcomputer 41 that executes the processes of steps S22 and S100 provides a predicting unit that predicts whether or not the exhaust pressure becomes a high pressure state after a predetermined time.

  When the on-off valve 26v1 is forcibly closed, full stop control is performed in step S19. However, with regard to the stop of the operation of the air pump 30p, the operation of the air pump 30p is continued until a predetermined time has elapsed after the start of the valve closing operation of the on-off valve 26v1, and the operation of the air pump 30p is stopped after the predetermined time has elapsed. .

  As described above, according to the present embodiment, the ozonizer 30 that generates ozone by the discharge from the electrode 31, the supply pipe 26 that supplies the ozone generated by the ozonizer 30 to the exhaust passage 10ex, and the supply path 26a by the supply pipe 26 And an on-off valve 26v1 for opening and closing. Therefore, by closing the on-off valve 26v1 when the exhaust pressure is high, exhaust can be prevented from flowing back into the interelectrode passage 31a through the supply passage 26a. Therefore, it is possible to suppress foreign matters such as soot contained in the exhaust from adhering to the electrode 31, and it is possible to suppress discharge from being hindered by foreign matter adhesion.

  Further, in the present embodiment, the on-off valve 26v1 is an electromagnetic type that opens and closes by an electromagnetic force generated by energization, and the operation of the on-off valve 26v1 is controlled by the first control means 41a. Therefore, since the on-off valve 26v1 can be opened or closed at any timing, it is possible to switch between prevention of exhaust inflow into the supply passage 26a and supply of ozone from the supply passage 26a at a suitable timing. Become.

  Furthermore, in the present embodiment, there is provided a predicting unit that predicts whether or not the pressure in the exhaust passage (exhaust pressure reaching value) after a predetermined time is higher than the predetermined pressure (air pump limit pressure). When it is predicted that the first control means 41a will be in a high pressure state, the first control means 41a closes the on-off valve 26v1. According to this, before the high pressure state is reached, the valve closing operation of the on-off valve 26v1 is started. Therefore, it is possible to further suppress the possibility that the exhaust gas flows backward compared to the case where the valve closing operation of the on-off valve 26v1 is started at the timing when the high pressure state is detected contrary to the present embodiment.

  Furthermore, according to this embodiment, the on-off valve 26v1 is provided on the upstream side of the reaction chamber 20a. For this reason, the fuel injected into the reaction chamber 20a can also be prevented from flowing back into the ozonizer 30 through the supply pipe 26 by closing the on-off valve 26v1. Therefore, it is possible to suppress the fuel as the reducing agent from adhering to the electrode 31 and preventing the discharge.

  Furthermore, according to this embodiment, the reduction catalyst is a substance containing at least silver. Specifically, a silver catalyst is supported on alumina coated on a carrier. By employing a silver catalyst in this way, the partial oxidation reaction of FIG. 3 is more likely to occur than when a platinum catalyst is employed, for example. Therefore, according to this embodiment that employs a silver catalyst, the NOx purification rate can be improved as compared with the case where a platinum catalyst is employed. In particular, the effect of improving the NOx purification rate is remarkably exhibited in the low temperature region of the temperature region where the catalyst temperature Tcat is activated.

  Furthermore, in this embodiment, the reducing agent heated to a predetermined temperature or higher by the heater 21 is partially oxidized by oxygen contained in the air to be reformed. According to this, partial oxidation of the fuel can be easily realized, and reforming of the reducing agent can be easily realized. Further, by heating the fuel with the heater 21, cracking that causes the fuel to decompose into a hydrocarbon compound having a small number of carbon atoms occurs. And since the boiling point of the hydrocarbon whose carbon number decreased by cracking becomes low, it is suppressed that the vaporized fuel returns to a liquid.

  Furthermore, in the present embodiment, ozone generated by the ozonizer 30 is supplied when a cold flame reaction is caused by strong oxidation control. Therefore, it is possible to accelerate the start time of the cold flame reaction and shorten the cold flame reaction time. Therefore, even if the reaction vessel 20 is downsized so that the residence time of the fuel in the reaction chamber 20a is shortened, the cold flame reaction can be completed within the residence time. Therefore, the reaction vessel 20 can be downsized.

(Second Embodiment)
In the present embodiment, the process of FIG. 3 according to the first embodiment is changed to the process shown in FIG. The process of FIG. 4 is a process that is repeatedly executed by the microcomputer 41 at a predetermined cycle when the engine 10 is operating, and is a process for forcibly closing the on-off valve 26v1.

  First, in step S30 of FIG. 4, the target air amount Atrg used in the control of FIG. 2 is acquired as the required air flow rate. In the subsequent step S31, the actual air amount detected by the air amount sensor 45 is acquired. In this way, the microcomputer 41 that executes the process of step S31 provides a blowing amount acquisition unit that acquires the blowing amount of ozone by the air pump 30p. Since the pressure in the supply passage 26a and the air flow rate are highly correlated, the pressure may be detected by a pressure sensor, and the actual air amount may be estimated based on the detection result.

  In the subsequent step S110, a shortage (flow rate deviation) of the actual air amount with respect to the required air flow rate is calculated, and it is determined whether or not this shortage is larger than a preset flow rate deviation threshold value. When it is determined that the flow rate deviation> the flow rate deviation threshold value, it is considered that the exhaust pressure is flowing back to the supply passage 26a or is in a state where there is a high possibility of backflowing. Close the valve. When it is not determined that the flow rate deviation> the flow rate deviation threshold value, the process returns to step S30 without forcibly closing the on-off valve 26v1.

  As described above, according to the present embodiment, the first control unit 41a closes the on-off valve 26v1 based on the comparison between the actual air amount and the required air flow rate. Specifically, when it is determined that the flow rate deviation> the flow rate deviation threshold value, it is considered that the exhaust pressure is backflowing into the supply passage 26a or that there is a high possibility of backflowing, and the on-off valve 26v1 is closed. . Therefore, it is possible to suppress the exhaust gas from flowing backward through the supply passage 26 a and flowing into the interelectrode passage 31 a, and it is possible to suppress discharge from being hindered due to foreign matter adhesion to the electrode 31.

(Third embodiment)
In the present embodiment, the process of FIG. 4 according to the second embodiment is changed to the process shown in FIG. The process of FIG. 5 is a process that is repeatedly executed by the microcomputer 41 at a predetermined cycle when the engine 10 is operating, and is a process for forcibly closing the on-off valve 26v1.

First, in step S31 in FIG. 5, the actual air amount detected by the air amount sensor 45 is acquired in the same manner as in FIG. In a succeeding step S120, it is determined whether or not the acquired actual air amount is larger than a preset flow rate threshold value. If it is determined that the actual air quantity <flow threshold, considers the exhaust is flowing back into the supply passage 26a, or is in a state likely to reflux, in the subsequent step S200, the forced opening and closing valve 26v1 Close the valve. When it is not determined that the actual air amount <the flow rate threshold value, the process returns to step S31 without forcibly closing the on-off valve 26v1.

As described above, according to the present embodiment, the first control means 41a closes the on-off valve 26v1 based on the actual air amount. Specifically, if it is determined that the actual air quantity <flow threshold, considers the exhaust is flowing back into the supply passage 26a, or is in a state likely to flow back, to close actuated on-off valve 26v1 . Therefore, it is possible to suppress the exhaust gas from flowing backward through the supply passage 26 a and flowing into the interelectrode passage 31 a, and it is possible to suppress discharge from being hindered due to foreign matter adhesion to the electrode 31.

(Fourth embodiment)
In this embodiment, the process of FIG. 3 according to the first embodiment is changed to the process shown in FIG. The process of FIG. 6 is a process that is repeatedly executed by the microcomputer 41 at a predetermined cycle when the engine 10 is operated, and is a process for forcibly closing the on-off valve 26v1.

  First, in step S40 of FIG. 6, the exhaust pressure detected by the exhaust pressure sensor 44 is acquired. In subsequent step S130, it is determined whether or not the acquired exhaust pressure is larger than a preset exhaust pressure threshold (predetermined value). If it is determined that exhaust pressure> exhaust pressure threshold, it is considered that the exhaust pressure is backflowing into the supply passage 26a or that there is a high possibility of backflow, and in the subsequent step S200, the on-off valve 26v1 is forcibly set. Close the valve. If it is not determined that exhaust pressure> exhaust pressure threshold, the process returns to step S40 without forcibly closing the on-off valve 26v1.

  As described above, according to the present embodiment, the first control means 41a closes the on-off valve 26v1 based on the actual exhaust pressure. Specifically, when it is determined that exhaust pressure> exhaust pressure threshold, it is considered that the exhaust pressure is backflowing into the supply passage 26a or that there is a high possibility of backflow, and the on-off valve 26v1 is closed. . Therefore, it is possible to suppress the exhaust gas from flowing backward through the supply passage 26 a and flowing into the interelectrode passage 31 a, and it is possible to suppress discharge from being hindered due to foreign matter adhesion to the electrode 31.

(Fifth embodiment)
In the present embodiment, as shown in FIG. 7, the process of FIG. 3 according to the first embodiment and the process of FIG. 5 according to the third embodiment are combined. That is, in steps S20, S21, and S22, the engine load and the engine speed are acquired, and the exhaust pressure reached value is predicted based on the degree of change of the acquired value. Thereafter, the actual air amount by the air amount sensor 45 is acquired in step S31.

If it is determined in step S100 that the predicted exhaust pressure> the air pump limit pressure, and it is determined in step S120 that the actual air amount <the flow rate threshold value, then in step S200, the on-off valve 26v1 is forcibly closed. Operate the valve. If it is not determined that the predicted exhaust pressure value> the air pump limit pressure, or if it is not determined that the actual air amount <the flow rate threshold value, the process returns to step S20 without forcibly closing the on-off valve 26v1.

As described above, according to the present embodiment, the first control unit 41a closes the on-off valve 26v1 based on the amount of air discharged from the air pump 30p and the predicted exhaust pressure. Specifically, when it is determined that the exhaust pressure prediction value> the air pump limit pressure and it is determined that the actual air amount <the flow rate threshold value, it is considered that the exhaust pressure becomes higher than the air pump limit pressure after a predetermined time, The on-off valve 26v1 is closed. Therefore, compared with the case where the valve closing operation is performed based on the predicted exhaust pressure value without taking the air amount into account or the case where the valve closing operation is performed based on the air amount without considering the exhaust pressure predicted value, Accuracy can be improved.

(Sixth embodiment)
In this embodiment, as shown in FIG. 8, the process of FIG. 3 according to the first embodiment and the process of FIG. 6 according to the fourth embodiment are combined. That is, in steps S20, S21, and S22, the engine load and the engine speed are acquired, and the exhaust pressure reached value is predicted based on the degree of change of the acquired value. Thereafter, the exhaust pressure detected by the exhaust pressure sensor 44 is acquired in step S40.

  If it is determined in step S100 that the predicted exhaust pressure> the air pump limit pressure, and it is determined in step S130 that the exhaust pressure> the exhaust pressure threshold, then in step S200, the on-off valve 26v1 is forcibly closed. Operate the valve. When it is not determined that the predicted exhaust pressure> the air pump limit pressure, or when it is not determined that the exhaust pressure> the exhaust pressure threshold, the process returns to step S20 without forcibly closing the on-off valve 26v1.

  As described above, according to the present embodiment, the first control unit 41a closes the on-off valve 26v1 based on the current exhaust pressure and the predicted exhaust pressure. Specifically, when it is determined that the exhaust pressure prediction value> the air pump limit pressure and it is determined that the exhaust pressure> the exhaust pressure threshold value, it is considered that the exhaust pressure becomes higher than the air pump limit pressure after a predetermined time, The on-off valve 26v1 is closed. Therefore, compared with the case where the valve closing operation is performed based on the exhaust pressure prediction value without taking the exhaust pressure into consideration or the case where the valve closing operation is performed based on the exhaust pressure without taking the exhaust pressure prediction value into consideration, the prediction or detection of the backflow is not performed. Accuracy can be improved.

(Seventh embodiment)
In the first embodiment, the reducing agent addition device having a function of supplying ozone provides the ozone supply device according to the present invention. In contrast, in the present embodiment, the ozone supply device shown in FIG. 9 is provided, which is a device in which the reaction vessel 20, the heater 21, and the injection valve 22 shown in FIG. 1 are eliminated. The ozone supply device includes an ozonizer 30, an air pump 30p, a supply pipe 26, a connection pipe 23, an on-off valve 26v1, and an ECU 40.

Further, the NOx purification device 12 shown in FIG. 1 employs a reduction catalyst that selectively reacts the reducing agent with NOx in the presence of O ₂ . On the other hand, the NOx purification device according to this embodiment employs a reduction catalyst that stores NOx in a lean environment in the presence of O ₂ and reacts a reducing agent with NOx in a rich environment. As a specific example of the catalyst that captures NOx during lean combustion in this way, an occlusion reduction catalyst using platinum and barium supported on a carrier can be cited.

  In the control according to the present embodiment, the processing content shown in FIG. 2 is changed as follows. That is, the determinations in steps S11 and S12 shown in FIG. 2 are abolished, and the control of the reducing agent supply in steps S16, S17, and S18 is abolished. When it is determined in step S13 that the catalyst temperature is higher than T3, the full stop control in step S19 is performed.

  The processing of FIG. 3 is performed in the present embodiment as well as in the first embodiment. That is, when the exhaust pressure reaching value is higher than the air pump limit pressure, the on-off valve 26v1 is closed. Therefore, the backflow of the exhaust gas to the supply passage 26a can be suppressed.

(Eighth embodiment)
As shown in FIG. 10, the ozone supply device according to the present embodiment includes an open valve 26v2 in addition to the open / close valve 26v1. The release valve 26v2 is provided on the upstream side of the open / close valve 26v1 in the supply pipe 26, and switches the supply passage 26a between a communication state and an open state. In the open state, the gas in the supply passage 26a is opened to the atmosphere. In the communication state, the gas in the supply passage 26a is circulated without opening. The release valve 26v2 is an electromagnetic drive type and is controlled by the microcomputer 41. The microcomputer 41 when controlling the operation of the release valve 26v2 corresponds to the second control means 41b.

  In the present embodiment, the operation of the ozone supply device is controlled by the same processing as in the seventh embodiment. That is, the operations of the ozonizer 30 and the air pump 30p are controlled so as to supply an ozone amount corresponding to the NO amount, and the on-off valve 26v1 is opened when ozone is supplied. If there is a concern about the backflow of exhaust, the on-off valve 26v1 is forcibly closed.

  Furthermore, in this embodiment, the microcomputer 41 repeatedly executes the process shown in FIG. 11 at a predetermined cycle. First, in step S50 of FIG. 11, it is determined whether or not the forced closing operation of the on-off valve 26v1 is requested. When it is determined that there is a valve closing request, the process proceeds to step S51, and it is determined whether or not a predetermined time has elapsed since the valve closing operation of the on-off valve 26v1 was started.

  When it is determined that the predetermined time has elapsed, it is considered that the opening / closing valve 26v1 has completed the closing operation, and in the next step S300, the opening valve 26v2 is operated to open (opening operation) to Switch to the open state. On the other hand, if it is determined in step S50 that there is no valve closing request, or if it is not determined in step S51 that the predetermined period has elapsed, in step S310, the open valve 26v2 is activated (communication operation). Let the communication state continue.

  Note that when the on / off valve 26v1 is forcibly closed to perform the full stop control, the air pump 30p is continuously operated until a predetermined time has elapsed after the on / off valve 26v1 is started. The operation of the air pump 30p is stopped after a predetermined time has elapsed. Then, when the release valve 26v2 is opened, the duration of the air pump 30p is set so that the operation of the air pump 30p is still continued.

  As described above, according to the present embodiment, the opening valve 26v2 that switches between the open state in which the gas in the supply passage 26a is opened to the atmosphere and the communication state in which the gas in the supply passage 26a is in communication and the operation of the release valve 26v2 are controlled. Second control means 41b. Then, the first control means 41a closes the opening / closing valve 26v1 while the air pump 30p is operating, and the second control means 41b opens the opening valve 26v2 from the communication state after the opening / closing valve 26v1 is closed. Switch to.

  Thus, since the on-off valve 26v1 is closed during the operation of the air pump 30p, the discharge pressure of the air pump 30p operates without decreasing from the start to the completion of the valve closing operation. Therefore, it is possible to improve the certainty of suppressing the exhaust gas from flowing backward to the supply passage 26a. Moreover, after the on-off valve 26v1 is closed, the release valve 26v2 is switched from the communication state to the open state. For this reason, in the period from when the on-off valve 26v1 is closed until the discharge pressure of the air pump 30p decreases, the pressure on the upstream side of the on-off valve 26v1 and the downstream side of the air pump 30p is increased. Can be avoided. Therefore, it is possible to avoid the pressure in the supply passage 26a from increasing during the above period and damaging the supply pipe 26 and the like.

(Ninth embodiment)
The hardware configuration of the ozone supply apparatus according to this embodiment is the same as that of the eighth embodiment, and includes an open valve 26v2 in addition to the open / close valve 26v1. Then, the microcomputer 41 repeatedly executes the process shown in FIG. 12 at a predetermined cycle. First, in step S60 of FIG. 12, it is determined whether or not there is a drive request for the air pump 30p. When it is determined that there is a drive request, the process proceeds to step S61, and it is determined whether or not a predetermined time has elapsed since the start of driving the air pump 30p.

  If a negative determination is made that the predetermined time has not elapsed, it is considered that the discharge pressure of the air pump 30p has not increased sufficiently, and the release valve 26v2 is opened in the next step S300, while the next step S400. To keep the on-off valve 26v1 closed. On the other hand, if an affirmative determination is made that the predetermined time has elapsed, it is considered that the discharge pressure of the air pump 30p has increased sufficiently, and the release valve 26v2 is operated to communicate in the next step S300, while in the next step S410. The on-off valve 26v1 is opened.

  As described above, according to the present embodiment, the release valve 26v2 that switches between the open state and the communication state described above and the second control means 41b that controls the operation of the release valve 26v2 are provided. Then, until a predetermined time has elapsed from the start of the start of the air pump 30p, the first control means 41a closes the on-off valve 26v1, and the second control means operates the open valve 26v2 in an open state. On the other hand, after the predetermined time has elapsed, the first control means 41a opens the on-off valve 26v1, and the second control means 41b operates the open valve 26v2 in a communicating state.

  Thus, immediately after the start of the air pump 30p, the opening / closing valve 26v1 is closed and the opening valve 26v2 is opened, so that it is possible to prevent the backflow of the exhaust gas reliably and upstream of the opening / closing valve 26v1 and the air pump 30p. It is possible to avoid an increase in pressure on the downstream side. On the other hand, when a predetermined time has elapsed from the start of the start of the air pump 30p, the on-off valve 26v1 is opened and the open valve 26v2 is communicated, so that ozone can be supplied to the exhaust passage 10ex with a sufficiently increased discharge pressure.

(10th Embodiment)
The on-off valve 26v1 according to each of the above embodiments is an electromagnetic type controlled by the first control means 41a. On the other hand, the on-off valve 260 of this embodiment shown in FIG. 13 is a mechanical type that opens and closes according to the differential pressure between the downstream pressure and the upstream pressure of the on-off valve 260. Specifically, the on-off valve 260 includes a valve body 261 that opens and closes the supply passage 26a, and an elastic member 262 that applies an elastic force to the valve body 261 in the valve closing direction. When the pressure on the upstream side of the valve body 261 is low, the valve body 261 is closed by the elastic force. When the pressure on the upstream side of the valve body 261 is increased by the operation of the air pump 30p, the valve body 261 is opened by the pressure.

  As described above, according to the present embodiment, when the pressure difference between the upstream side and the downstream side of the valve body 261 exceeds a predetermined value, the valve is mechanically opened, and when it is less than the predetermined value, the valve is closed by an elastic force. Therefore, it is possible to suppress the backflow of the exhaust gas to the supply passage 26a while making the microcomputer 41 need not control the on-off valve 260.

(Other embodiments)
The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made as illustrated below. Not only combinations of parts that clearly show that combinations are possible in each embodiment, but also combinations of the embodiments even if they are not explicitly stated unless there is a problem with the combination. Is also possible.

  In the first embodiment, the exhaust pressure attainment value is predicted based on the degree of change in the engine load and the engine speed. On the other hand, the exhaust pressure reach value may be predicted based on the degree of change in the accelerator pedal depression amount and the engine speed.

  The ozone supply apparatus according to the present invention may be applied to a combustion system including a catalyst that oxidizes and purifies CO and HC (predetermined components) in exhaust gas. In this case, by supplying ozone to the exhaust passage 10ex, the oxidation function of the oxidation catalyst can be enhanced, which is useful. If ozone is excessively supplied at the time of a low demand and adsorbed to the oxidation catalyst, the adsorbed ozone can contribute to the oxidation when the state changes to a high demand state.

  In the embodiment shown in FIG. 1, an ozone supply device is applied to a combustion system mounted on a vehicle. On the other hand, an ozone supply device may be applied to a stationary combustion system. In the embodiment shown in FIG. 1, an ozone supply device is applied to a compression self-ignition diesel engine, and light oil used as a fuel for combustion is used as a reducing agent. In contrast, an ozone supply device may be applied to an ignition ignition type gasoline engine, and gasoline used as a fuel for combustion may be used as a reducing agent.

  Means and / or functions provided by the ECU 40 (control device) can be provided by software recorded in a substantial storage medium and a computer that executes the software, only software, only hardware, or a combination thereof. For example, if the controller is provided by a circuit that is hardware, it can be provided by a digital circuit including a number of logic circuits, or an analog circuit.

  DESCRIPTION OF SYMBOLS 10 ... Internal combustion engine, 10ex ... Exhaust passage, 26 ... Supply pipe, 26a ... Supply passage, 26v1, 260 ... Open / close valve, 30 ... Ozonizer, 31 ... Electrode.

Claims (2)

A predetermined component in the exhaust gas by supplying ozone to the upstream side of the catalyst in the exhaust passage, which is disposed in the exhaust passage (10ex) of the internal combustion engine (10) and provided with a catalyst for purifying exhaust gas. In the ozone supply device that oxidizes
An ozonizer (30) having an electrode (31) for discharging into the air and generating ozone by the discharge;
A supply pipe (26) forming a supply passage (26a) for supplying ozone generated by the ozonizer to the exhaust passage;
An air pump (30p) for blowing ozone into the supply passage;
An electromagnetic on- off valve (26v1 ) provided in the supply pipe and opening / closing the supply passage by opening / closing by an electromagnetic force generated by energization ;
First control means (41a) for controlling the operation of the on-off valve;
Predicting means (S22, S100) for predicting whether or not the pressure in the exhaust passage after a predetermined time is higher than a predetermined pressure;
An air volume acquisition means (S31) for acquiring an air volume of ozone by the air pump;
Equipped with a,
The first control unit closes the on-off valve when the predicting unit is predicted to be in the high pressure state and the blast amount acquired by the blast amount acquiring unit is smaller than a preset flow rate threshold value. An ozone supply device characterized by operating a valve . A predetermined component in the exhaust gas by supplying ozone to the upstream side of the catalyst in the exhaust passage, which is disposed in the exhaust passage (10ex) of the internal combustion engine (10) and provided with a catalyst for purifying exhaust gas. In the ozone supply device that oxidizes
An ozonizer (30) having an electrode (31) for discharging into the air and generating ozone by the discharge;
A supply pipe (26) forming a supply passage (26a) for supplying ozone generated by the ozonizer to the exhaust passage;
An electromagnetic on-off valve (26v1) that is provided in the supply pipe and opens and closes by opening and closing with an electromagnetic force generated by energization;
First control means (41a) for controlling the operation of the on-off valve;
Predicting means (S22, S100) for predicting whether or not the pressure in the exhaust passage after a predetermined time is higher than a predetermined pressure;
With
The first control means, said by the prediction means is expected to be the high pressure and wherein when the pressure in the exhaust passage is higher than the exhaust pressure threshold value, to the feature that is closed actuating the on-off valve Luo Zon feeding device.

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