JP2006183573A - Exhaust emission control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control system rapidly and efficiently heating an exhaust emission control catalyst in a short period of time. <P>SOLUTION: In the exhaust emission control system provided with an internal combustion engine 1, the exhaust emission control catalyst 2 purifying exhaust gas of the internal combustion engine 1, and a warming up means including a reformer 3 forming reformed gas by reforming hydrocarbon fuel, a combustion part 4 burning the reformed gas with catalyst, and a supply part 5 supplying heat generated by the catalyst combustion to an outer circumference surface of the exhaust emission control catalyst 2, a compressor, a blower or the like are not affected by back pressure and operate efficiently since an exhaust gas passage of the internal combustion engine and a passage through which the reformed gas passes are not communicated. The exhaust emission control catalyst can be rapidly and efficiently heated to operational temperature in a short period time since reformed gas is supplied to an outer circumference surface of the exhaust emission control catalyst. Consequently, the exhaust emission control system rapidly and efficiently heating the exhaust emission control catalyst to operational temperature in the short period of time can be provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an exhaust purification system, and more particularly to control for heating an exhaust purification catalyst to an operating temperature with high efficiency within a short time.

  Hazardous substances such as carbon monoxide, nitrogen carbide, and nitrogen oxides contained in the exhaust gas of the internal combustion engine are purified by the exhaust purification catalyst, but when the exhaust gas temperature is low just after the start of the internal combustion engine (for example, 350 ° C.) In the following, the exhaust purification catalyst is not effective. Therefore, generally, a method is known in which the exhaust purification catalyst is electrically heated at the time of cold start to promote the reaction.

  Further, the following methods have been proposed as a method for heating the exhaust purification catalyst. For example, in Patent Document 1, a gas that undergoes an oxidation reaction is generated by an exhaust purification catalyst, this gas is introduced into the exhaust purification catalyst to cause an oxidation reaction, and the exhaust purification catalyst is heated using heat generated by this oxidation reaction. Techniques to do this are disclosed.

  Patent Document 2 discloses that in a vehicle including an internal combustion engine and a fuel cell, heat exhausted from the fuel cell via the exhaust gas can be at least partially guided to the exhaust purification catalyst. In addition, a technique is disclosed in which a thermal connection portion is provided between the fuel cell and the exhaust purification catalyst to heat the exhaust purification catalyst quickly.

JP-A-7-127447 Special table 2004-525300 gazette

  However, in Patent Document 1, in order to introduce the gas into the exhaust purification catalyst, the gas is introduced into the exhaust passage of the internal combustion engine as a means. Therefore, the gas introduction passage communicates with the exhaust passage of the internal combustion engine, and as a result, is affected by the exhaust pressure of the internal combustion engine. Thereby, for example, when the exhaust pressure of the internal combustion engine changes with the load fluctuation, the rotational speed of the compressor, blower, etc. that are driven to introduce the gas or oxygen-containing gas into the exhaust purification catalyst also changes. As a result, system efficiency decreases.

  Further, in Patent Document 2, when a thermal connection portion is provided between the fuel cell and the exhaust purification catalyst, at least the fuel cell is operated at an operating temperature after the vehicle control system is activated until the fuel cell is activated. Therefore, the exhaust purification catalyst is not warmed up until the heat exhausted through the exhaust gas by the power generation of the fuel cell is guided to the exhaust purification catalyst. Not. Therefore, when the internal combustion engine is started during that time, the exhaust purification catalyst does not exhibit its effectiveness.

  The present invention has been made in view of the above problems, and an object thereof is to provide an exhaust purification system that heats an exhaust purification catalyst rapidly in a short time with high efficiency.

  The present invention relates to an internal combustion engine, an exhaust purification catalyst that purifies exhaust gas of the internal combustion engine, a reformer that reforms a hydrocarbon fuel to generate reformed gas, and catalytically burns the reformed gas An exhaust purification system comprising: a combustion unit; and a warm-up unit having a supply unit that supplies heat generated by the catalytic combustion to the outer peripheral surface of the exhaust purification catalyst. According to this configuration, since the passage through which the reformed gas passes and the exhaust passage of the internal combustion engine are not communicated with each other, there is no influence of the back pressure, and an efficient operation of the compressor, blower, or the like is possible. At the same time, since the reformed gas is supplied to the outer peripheral surface of the exhaust purification catalyst, the exhaust purification catalyst can be efficiently heated to the operating temperature rapidly within a short time.

  Further, the warm-up means can be configured to include the combustion part for catalytically burning the reformed gas on the outer peripheral surface of the exhaust purification catalyst. With this configuration, it is possible to suppress communication between the exhaust gas passage and the reformed gas passage of the internal combustion engine, so that the influence of back pressure on the compressor, blower, and the like can be removed. Moreover, since the combustion part is provided in the outer peripheral surface of the exhaust purification catalyst, it is possible to suppress heat loss when transferring the heat generated in the combustion part to the supply part.

  Further, when a fuel cell is provided, the reformed gas introduced into the fuel cell can be branched at the fuel cell outlet and introduced into the combustion section. With this configuration, part of the heat generated in the reforming reaction can be supplied to the fuel cell via the reformed gas, so that the time required for the fuel cell to be heated to the operating temperature can be shortened. System efficiency can be improved.

  Further, the warm-up means has a valve provided in a reformed gas passage from the reformer to the combustion section, and when the system is started, before the exhaust purification catalyst is heated to the operating temperature, When the load is driven by the battery and the warm-up is completed after that, the internal combustion engine is started, and the reformed gas is shut off by controlling the valve. With this configuration, since the load can be driven without starting the internal combustion engine until the exhaust purification catalyst is heated to the operating temperature, more excellent exhaust purification can be realized. Further, after the exhaust purification catalyst is rapidly heated to the operating temperature within a short time, the valve is shut off to use the reformed gas as fuel for the fuel cell, thereby improving the efficiency of the system. be able to.

  According to the present invention, it is possible to provide an exhaust purification system that heats an exhaust purification catalyst rapidly within a short time with high efficiency.

  Hereinafter, the best mode for carrying out the present invention will be described.

  FIG. 1 is a schematic diagram illustrating a configuration of an exhaust purification system according to a first embodiment having an internal combustion engine and a reforming unit that reforms a hydrocarbon-based fuel to generate a reformed gas. As shown in FIG. 1, the exhaust purification system includes an internal combustion engine 1, an exhaust purification catalyst 2, a reformer 3, a combustion unit 4, a supply unit 5, a control unit 8, and a sensor 9. As will be described later, the constituent elements shown by solid lines in the block of FIG. 1 mean the minimum configuration necessary for rapidly heating the exhaust purification catalyst 2 within a short time and purifying the exhaust, and are indicated by broken lines. The constituent elements shown are arbitrarily provided as necessary.

  The internal combustion engine 1 is, for example, a gasoline engine, and burns a mixture of a fuel raw material and air. The exhaust purification catalyst 2 purifies the exhaust gas discharged from the internal combustion engine 1. At this time, in a state where the exhaust gas temperature is low (for example, 350 ° C. or less) immediately after the internal combustion engine 1 is started, the exhaust purification catalyst 2 is not effective.

  The reformer 3 reforms the reforming raw material and generates a reformed gas. The generated reformed gas is introduced from the outlet of the reformer 3 into the combustion unit 4 provided on the outer periphery of the exhaust purification catalyst 2. The combustion unit 4 performs catalytic combustion of hydrogen or the like of the reformed gas component. The combustion unit 4 includes a catalyst made of a noble metal such as platinum or palladium. The supply unit 5 supplies the heat generated by the catalytic combustion to the exhaust purification catalyst 2 mounted on the inside thereof, and warms up the exhaust purification catalyst 2 rapidly. After the exhaust purification catalyst 2 reaches the operating temperature, the exhaust purification catalyst 2 can exert its effectiveness.

  When the control of the exhaust purification system having such a configuration is started, the temperature of the exhaust purification catalyst 2 is in a low state. When the internal combustion engine 1 is started in this state, the exhaust purification catalyst 2 cannot exhibit its effect because the temperature of the exhaust purification catalyst 2 has not reached the operating temperature. Therefore, the present invention has a configuration for rapidly warming up the exhaust purification catalyst 2 within a short time, and has a configuration for controlling the start of the internal combustion engine 1 in accordance with the temperature state of the exhaust purification catalyst 2. At the start of control of the drive system, the exhaust purification catalyst 2 is rapidly heated to its operating temperature within a short time, and after the exhaust purification catalyst 2 reaches the operating temperature, the exhaust purification catalyst 2 can be effective. The internal combustion engine 1 can be started.

  Specifically, in the exhaust purification system shown in FIG. 1, the temperature generated by the exhaust purification catalyst warming-up means for supplying heat generated by catalytic combustion of the reformed gas to the exhaust purification catalyst and the temperature state of the exhaust purification catalyst 2 is obtained. Correspondingly, a control means for starting the internal combustion engine 1 is provided.

  The warming-up means exhausts the heat generated by the reformer 3, the combustion section 4 provided on the outer periphery of the exhaust purification catalyst 2 for catalytically burning the reformed gas generated by the reformer 3, and exhaust heat purification. A supply unit 5 for supplying the catalyst 2 is provided. Oxygen is required when the reformed gas is catalytically combusted in the combustion unit 4, but for example, oxygen in the air may be supplied as illustrated. With this configuration, heat generated by catalytic combustion is generated on the outer periphery of the exhaust purification catalyst 2 to be warmed up, and the heat is supplied to the exhaust purification catalyst 2 provided on the inner side. As a result, it is possible to supply heat to the exhaust purification catalyst 2 with high efficiency. Since the reformed gas passage does not communicate with the exhaust gas passage but communicates with the combustion section 4 provided on the outer periphery of the exhaust purification catalyst 2, the influence of the back pressure on the compressor, blower, etc. can be eliminated. Efficiency improvement can be realized.

  The control means includes a sensor 9 that detects the temperature state of the exhaust purification catalyst 2 and a control unit 8 that controls the start of the internal combustion engine 1 in accordance with an output signal of the sensor 9. For example, if the temperature of the exhaust purification catalyst 2 is equal to or lower than the operating temperature, the control unit 8 continuously monitors the output signal of the sensor 9, and if the temperature of the exhaust purification catalyst 2 reaches the operating temperature, the internal combustion engine 1 is monitored. Start. With this configuration, it is possible to prevent the internal combustion engine 1 from being started when the exhaust purification catalyst 2 is below the operating temperature, and as a result, the exhaust purification catalyst 2 can exhibit its effectiveness.

  FIG. 1 shows the minimum configuration necessary for rapidly heating the exhaust purification catalyst 2 within a short time to purify the exhaust, and reforming as shown by the broken line in FIG. A heat exchanger 6 that converts the heat of the gas into the operating temperature of the fuel cell 7, an anode, a cathode, and an electrolyte. From hydrogen in the reformed gas supplied to the anode and air (oxygen) supplied to the cathode A fuel cell 7 that generates water and generates electric power, a valve 10 that can control the passage of the reformed gas from the reformer 3 to the combustion unit 4 according to the state, and can be controlled to be communicable, and electric power that can drive the vehicle The battery 11 (secondary battery) may be stored.

  Next, the control performed by the control unit 8 to heat the exhaust purification catalyst 2 when starting the exhaust purification system will be described. Here, the case of a vehicle equipped with an exhaust purification system is illustrated. FIG. 4 is a flowchart for realizing control performed by the control unit 8 shown in FIG. The control unit 8 is constituted by a microcomputer that executes a program.

  As shown in FIG. 4, the vehicle control system is first activated.

  After starting the control system, the control unit 8 starts the reformer 3 (step S1). The reformed gas generated by the reforming reaction in the reformer 3 is introduced into the combustion unit 4 provided on the outer periphery of the exhaust purification catalyst 2, and hydrogen or the like of the reformed gas component is catalytically combusted. Heat generated by catalytic combustion is supplied to the exhaust purification catalyst 2 mounted on the inside thereof, and the exhaust purification catalyst 2 is rapidly warmed up.

  In step S1, when it is determined from the output signal of the sensor 9 provided in the exhaust purification catalyst 2 that the temperature is equal to or lower than the setting (the exhaust purification catalyst 2 is not warmed up to the operating temperature), the control unit 8 Continues to monitor the sensor 9 (step S2).

  In step S2, when it is determined from the output signal of the sensor 9 provided in the exhaust purification catalyst 2 that the temperature is not lower than the set value (the exhaust purification catalyst 2 has been warmed up to the operating temperature), the control unit 8 Then, the internal combustion engine 1 is started (step S3).

  As described above, since the internal combustion engine 1 is controlled to start after the exhaust purification catalyst 2 is rapidly warmed up, more excellent exhaust purification can be achieved. The system configuration eliminates the effect of back pressure on the compressor, blower, etc. by connecting the reformed gas passage to the combustion section 4 provided on the outer periphery of the exhaust purification catalyst 2 without communicating with the exhaust gas passage. As a result, system efficiency can be improved. Furthermore, heat can be generated by catalytic combustion on the outer periphery of the exhaust purification catalyst 2 to be warmed up, and the heat can be supplied to the exhaust purification catalyst 2 provided on the inner side, resulting in a structure with less heat loss. Highly efficient heat can be supplied to the exhaust purification catalyst 2.

  FIG. 2 is a schematic diagram illustrating a configuration of a hybrid system including the exhaust purification system according to the second embodiment. As shown in FIG. 2, the hybrid system includes an internal combustion engine 1, an exhaust purification catalyst 2, a reformer 3, a combustion unit 4, a supply unit 5, a fuel cell 7, a control unit 8, and a sensor 9. The exhaust purification system according to the second embodiment includes an internal combustion engine 1, a fuel cell 2, and a reformer 3. The hybrid system may include a heat exchanger 6 and a battery 11 between the reformer 3 and the fuel cell 7 as necessary, and the exhaust purification system may be configured to include the reformer 3 as necessary. And a device including a valve 10 or the like between the passages of the reformed gas communicating with the combustion unit 4.

  When the fuel cell 7 is provided as shown in FIG. 2, the reformed gas introduced into the fuel cell 7 is branched from the outlet of the fuel cell 7 and then introduced into the combustion unit 4. The combustion unit 4 catalytically combusts hydrogen or the like of the reformed gas component, and the supply unit 5 rapidly heats up the exhaust purification catalyst 2 by supplying heat generated by catalytic combustion to the exhaust purification catalyst 2. . As the oxygen introduction path for catalytic combustion of hydrogen or the like, oxygen in the air can be supplied as shown in FIG. 1, and oxygen is supplied to the cathode of the fuel cell 7 as shown in FIG. A cathode pump 12 may be used. With this configuration, the reformed gas is catalytically combusted, the heat is supplied to the exhaust purification catalyst 2, the exhaust purification catalyst 2 is heated to the operating temperature, and at the same time, part of the heat of the reformed gas is supplied to the fuel cell 7. can do.

  The fuel cell 7 is, for example, a hydrogen separation membrane type battery. The hydrogen separation membrane type battery has an electrolyte membrane in which an electrolyte layer having proton conductivity is laminated on a hydrogen permeable metal layer. Of course, other types of fuel cells can be used.

  When a control system for a vehicle having a hybrid system including an exhaust purification system having such a configuration is started, normally, at least a time until the fuel cell 7 reaches the operating temperature is required before the fuel cell 7 can be operated. I need. However, from the viewpoint of reducing the exhaust gas itself containing harmful substances from the internal combustion engine 1, the fuel cell 7 operates as soon as possible after the vehicle control system is started, and uses the electric power for driving the vehicle. Thus, it is desirable that the internal combustion engine 1 can be stopped. Therefore, the present invention includes a fuel cell 7 between the reformed gas introduction passages from the reformer 3 to the combustion unit 4 so that a part of the heat of the reformed gas can be supplied to the fuel cell 7.

  Specifically, the hybrid system including the exhaust purification system shown in FIG. 2 supplies a part of the heat of the reformed gas to the fuel cell 7. As in the configuration of FIG. 1, according to the warming-up means of the exhaust purification catalyst for supplying heat generated by catalytic combustion of the reformed gas to the exhaust purification catalyst, and the temperature state of the exhaust purification catalyst 2 as in the configuration of FIG. It is good also as a structure which has a control means to start the internal combustion engine 1. FIG.

  A hybrid system including the exhaust purification system of FIG. 2 includes a reformer 3, a combustion unit 4, and a fuel cell 7. Moreover, the structure including the heat exchanger 6 which converts a part of the heat of the reformed gas and supplies the fuel cell 7 may be used. When the vehicle control system is started, the temperature of the fuel cell 7 is low. With this configuration, part of the heat generated by the reforming reaction in the reformer 3 is supplied to the fuel cell 7 via the reformed gas. Therefore, the time required for the fuel cell 7 to be heated to the operating temperature can be shortened. The warm-up means of the exhaust purification catalyst 2 may have the same configuration as in FIG. The control means for starting the internal combustion engine 1 also controls the fuel cell 7 in addition to the configuration of FIG. After the control unit 8 starts the internal combustion engine 1 in response to the temperature of the exhaust purification catalyst 2 reaching the operating temperature by the output signal of the sensor 9, the control unit 8 performs a predetermined operation such as the operating temperature. If the conditions are met, the fuel cell 7 is started. In such a configuration, it is possible to prevent the internal combustion engine 1 from being started while the exhaust purification catalyst 2 is at the operating temperature or lower, and after the fuel cell 7 is started, the internal combustion engine 1 is operated under predetermined operating conditions. By stopping, the amount of exhaust gas discharged from the internal combustion engine 1 can be suppressed, and by supplying a part of the heat of the reformed gas, the fuel cell 7 reaches the operating temperature necessary for its start. Can be shortened.

  Next, the control performed by the control unit 8 to heat the exhaust purification catalyst 2 when starting the hybrid system including the exhaust purification system will be described. Here, it illustrates as a case of the vehicle provided with the hybrid system containing an exhaust gas purification system. FIG. 5 is a flowchart for realizing the control performed by the control unit 8 shown in FIG.

  As shown in FIG. 5, first, the vehicle control system is activated.

After starting the control system, the control unit 8 starts the reformer 3 (step S11).
The reformed gas generated by the reforming reaction in the reformer 3 is introduced into the fuel cell 7. The reformed gas passage is branched from the outlet of the fuel cell 7 and the reformed gas is introduced from the outlet of the fuel cell 7 into the combustion section 4 provided on the outer periphery of the exhaust purification catalyst 2 to catalytically burn the reformed gas component hydrogen or the like. As a result, heat generated by catalytic combustion is supplied to the exhaust purification catalyst 2 mounted on the inside thereof, and the exhaust purification catalyst 2 is rapidly warmed up.

  In step S11, when it is determined from the output signal of the sensor 9 provided in the exhaust purification catalyst 2 that the temperature is equal to or lower than the setting (the exhaust purification catalyst 2 is not warmed up to the operating temperature), the control unit 8 Continues to monitor the sensor 9 (step S12).

  In step S12, when it is determined from the output signal of the sensor 9 provided in the exhaust purification catalyst 2 that the temperature is not lower than the set value (the exhaust purification catalyst 2 has been warmed up to the operating temperature), the control unit 8 Then, the internal combustion engine 1 is started (step S13).

  In step S13, when the conditions (for example, operating temperature) which can start the fuel cell 7 are prepared, the fuel cell 7 is started (step S14).

  As described above, since a part of the heat generated in the reforming reaction can be supplied to the fuel cell 7 via the reformed gas, the time required for the fuel cell 7 to be heated to the operating temperature is reduced. Shortening can be achieved and the efficiency of the system can be improved.

  FIG. 3 is a schematic diagram illustrating a configuration of a hybrid system including the exhaust purification system according to the third embodiment. As shown in FIG. 3, the hybrid system includes an internal combustion engine 1, an exhaust purification catalyst 2, a reformer 3, a combustion unit 4, a supply unit 5, a fuel cell 7, a control unit 8, a sensor 9, a valve 10, and a battery 11. Including. The exhaust purification system according to the third embodiment includes an internal combustion engine 1, a fuel cell 7, a valve 10, a battery 11, and a reformer 3. The hybrid system may include a heat exchanger 6 between the reformer 3 and the fuel cell 7 as necessary. Here, it illustrates as a case of the vehicle provided with the hybrid system containing an exhaust gas purification system.

  In the case of a hybrid system including the fuel cell 7, the valve 10, and the battery 11 as shown in FIG. 3, the control unit 8 is driven so that the load is driven by the power of the battery 11 when the control system is activated. Control. With this configuration, before the exhaust purification catalyst 2 reaches the operating temperature, the vehicle is driven by the electric power of the battery 11 without starting the internal combustion engine 1, and the exhaust purification catalyst 2 reaches the operating temperature and exhibits its effectiveness. After that, the internal combustion engine 1 can be started. Further, after the exhaust purification catalyst 2 reaches the operating temperature, the controller 8 closes the valve 10 and shuts off the valve 10 to use the reformed gas as fuel for the fuel cell, thereby improving the efficiency of the system. be able to.

  When the vehicle control system having the exhaust purification system having such a configuration is activated, when the battery that stores the electric power that can drive the vehicle is not provided, the exhaust purification catalyst 2 is activated when the vehicle control system is activated. Until the engine is heated to the operating temperature, the internal combustion engine 1 cannot be started, so that a waiting time is required until the driver can operate. However, starting the internal combustion engine 1 before the exhaust purification catalyst 2 reaches the operating temperature is not effective from the viewpoint of exhaust purification because the exhaust purification catalyst 2 cannot exhibit its effect. Therefore, the present invention includes a battery 11 that stores electric power that can drive the vehicle, and the vehicle can be driven by the electric power of the battery 11 until the exhaust purification catalyst 2 reaches the operating temperature. Can be driven. In the exhaust purification system having the above-described configuration, as a warm-up means for the exhaust purification catalyst 2, a configuration in which the exhaust purification catalyst 2 similar to the configuration in FIG. 1 is rapidly heated and a reformed gas similar to the configuration in FIG. A configuration in which a part of heat is supplied to the fuel cell 7 may be used. Further, the control means may be configured to control the start of the internal combustion engine 1 in accordance with the temperature state of the exhaust purification catalyst 2. In the hybrid system including this exhaust purification system, the control means includes the internal combustion engine 1, the fuel cell 7, the control unit 8, the valve 10, and the battery 11, and the control unit 8 includes the exhaust purification catalyst 2. After the temperature reaches the operating temperature, the internal combustion engine 1 is started, and the valve 10 is shut off to use the reformed gas as fuel for the fuel cell 7, thereby improving the efficiency of the system. Thereafter, the drive control by the power of the battery 11 is stopped, and the fuel cell 7 is started when the operating conditions such as the operating temperature are met. By having the battery 11, the vehicle can be driven by the electric power of the battery 11 without starting the internal combustion engine 1 even before the exhaust purification catalyst 2 reaches the operating temperature, so that the vehicle is driven immediately after the vehicle control system is activated. can do.

  In this way, the reformed gas is supplied to the combustion unit 4, and the supply unit 5 supplies the heat generated by the catalytic combustion to the exhaust purification catalyst 2, thereby rapidly heating the exhaust purification catalyst 2 within a short time. Can do. In addition, the reformed gas combustion section 4 is provided on the outer periphery of the exhaust purification catalyst 2, the reformed gas reformer 3 is introduced into the combustion section 4 via the fuel cell 7, and after the control system is started. A battery 11 for driving the vehicle before the exhaust purification catalyst 2 is warmed up, and a valve 10 for shutting off the reformed gas introduction path from the reformer to the combustion section after the exhaust purification catalyst 2 reaches the operating temperature. This makes it possible to realize a hybrid system including an exhaust purification system that is highly efficient.

  Next, the control performed by the control unit 8 to heat the exhaust purification catalyst 2 when the vehicle is started will be described. FIG. 6 is a flowchart for realizing the control performed by the control unit 8 shown in FIG.

  As shown in FIG. 6, first, the vehicle control system is activated.

  After starting the control system, the control unit 8 controls the driving force so as to drive the vehicle with the battery (step S21).

  In step S21, the control unit 8 activates the reformer 3 while driving the vehicle with the battery (step S22).

  The reformed gas generated by the reforming reaction in the reformer 3 is introduced into the fuel cell 7. Branching the reformed gas from the outlet of the fuel cell 7 and introducing the reformed gas from the outlet of the fuel cell 7 into the combustion section 4 provided on the outer periphery of the exhaust purification catalyst 2 to catalytically burn the reformed gas component hydrogen or the like Thus, heat generated by catalytic combustion is supplied to the exhaust purification catalyst 2 mounted on the inside thereof, and the exhaust purification catalyst 2 is rapidly warmed up.

  In step S22, when it is determined from the output signal of the sensor 9 provided in the exhaust purification catalyst 2 that the temperature is equal to or lower than the setting (the exhaust purification catalyst 2 is not warmed up to the operating temperature), the control unit 8 Continues to monitor the sensor 9 (step S23).

  In step S23, when it is determined from the output signal of the sensor 9 provided in the exhaust purification catalyst 2 that the temperature is not below the setting (the exhaust purification catalyst 2 has been warmed up to the operating temperature), the control unit 8 Then, the internal combustion engine 1 is started.

  At the same time, when it is determined from the output signal of the sensor 9 provided in the exhaust purification catalyst 2 that the temperature is not below the set value (the exhaust purification catalyst 2 has been warmed up to the operating temperature), the control unit 8 The valve provided in the reformed gas passage between the mass device and the combustion section is shut off (step S24).

  In step S24, when the internal combustion engine 1 is started, the control unit 8 stops control of driving of the vehicle by the battery 11 (step S25).

  In step S25, when the conditions (for example, operating temperature) for starting the fuel cell 7 are met, the fuel cell 7 is started (step 26).

  FIG. 7 is a schematic diagram showing an example when the hybrid system is applied to an automobile. As shown in FIG. 3, the hybrid vehicle 200 includes a hybrid system 100, a battery 11, a power generation device 21, a power transmission device 22, a plurality of wheels 23, and a regeneration device 24. The hybrid system 100 has the configuration shown in FIGS. In FIG. 7, the battery 11 is illustrated separately from the hybrid system 100 for convenience.

  The electric power generated in the fuel cell of the hybrid system 100 is supplied to the power generation device 21 or stored in the battery 11 and then supplied to the power generation device 21. The power generation device 21 includes a converter, an inverter, an electric motor, and the like, converts electric power supplied from the hybrid system 100 or the battery 11 into a shaft output, and transmits the shaft output to the power transmission device 22. The power transmission device 22 transmits the given shaft output to the wheel 23. As a result, the hybrid vehicle 200 starts operating. Subsequently, the hybrid vehicle 200 switches the power to the internal combustion engine as the load increases. First, the power transmission device 22 stops supplying the shaft output from the power generation device 21. Next, power generated by the internal combustion engine 1 of the hybrid system 100 is given to the power transmission device 22 as a shaft output. The power transmission device 22 transmits the given shaft output to the wheel 23. If the load further increases, the power transmission device 22 transmits the shaft output given from both the internal combustion engine of the hybrid system 100 and the power generation device 21 to the wheels 23. The regenerative device 24 includes a generator and the like. When the user decelerates the hybrid vehicle 200, the generator of the regenerative device 24 converts the power of the wheels 23 into electric power and supplies the converted electric power to the battery 11.

  In such a hybrid vehicle 200, the exhaust purification system in the hybrid system 100 operates as described above.

  As described above, when the system includes the battery 11 that can drive the vehicle, the vehicle can be driven without starting the internal combustion engine 1 until the exhaust purification catalyst 2 is heated to the operating temperature. Therefore, after the exhaust purification catalyst 2 is heated to the operating temperature, the valve 10 is shut off in order to use the reformed gas as the fuel for the fuel cell 7. Can improve system efficiency.

It is a figure which shows the structure of the exhaust gas purification system which concerns on Example 1 of this invention. It is a figure which shows the discard purification system which concerns on Example 2 of this invention. It is a figure which shows the structure of the exhaust gas purification system which concerns on Example 3 of this invention. It is an operation | movement flowchart of the control part shown in FIG. It is an operation | movement flowchart of the control part shown in FIG. It is an operation | movement flowchart of the control part shown in FIG. It is a schematic diagram which shows an example at the time of applying a hybrid system to a motor vehicle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Exhaust purification catalyst 3 Reformer 4 Combustion part 5 Supply part 6 Heat exchanger 7 Fuel cell 8 Control part 9 Sensor 10 Valve 11 Battery 12 Cathode pump 21 Power generation device 22 Power transmission device 23 Wheel 24 Regeneration device 100 Hybrid system 200 Hybrid vehicle

Claims (4)

An internal combustion engine;
An exhaust purification catalyst for purifying the exhaust gas of the internal combustion engine;
A reformer for reforming hydrocarbon fuel to generate reformed gas;
A warm-up means having a combustion section for catalytic combustion of the reformed gas, and a supply section for supplying heat generated by the catalytic combustion to the outer peripheral surface of the exhaust purification catalyst;
An exhaust purification system comprising: The exhaust gas purification system according to claim 1, wherein the warm-up unit includes the combustion portion for catalytically burning the reformed gas on an outer peripheral surface of the exhaust gas purification catalyst. The exhaust gas purification system according to claim 1 or 2, wherein the reformed gas introduced into the fuel cell is branched at the fuel cell outlet and introduced into the combustion section. The warming-up means has a valve provided in a reformed gas passage from the reformer to the combustion section, and at the time of system start-up, until the exhaust purification catalyst is heated to the operating temperature, the battery The load is driven, and when the warm-up is completed after that, the internal combustion engine is started, and the valve is controlled to shut off the reformed gas. Exhaust purification system.

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