Fuel reformation device and internal combustion engine having the same

Abstract

To appropriately adjust an oxygen concentration in a fuel reformation device and an internal combustion engine having the same.SOLUTION: The present invention includes: a fuel reformer 20 provided in an EGR path that returns a part of an exhaust gas of an internal combustion engine 200 to a downstream of an intake throttle 10 provided to an intake pipe; an air supply path connecting an upstream of the intake throttle 10 of the internal combustion engine 200 to an upstream of the fuel reformer 20; an EGR flow rate adjustment valve 16 provided between an exhaust pipe of the internal combustion engine 200 and a connection part with the air supply path in the EGR path; and an air flow rate adjustment valve 26 provided to the air supply path. Flow rates of the fuel, exhaust gas, and air are adjusted by the EGR flow rate adjustment valve 16 and the air flow rate adjustment valve 26 and supplied to the fuel reformer 20.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a fuel reformer and an internal combustion engine equipped with the same. [Background technology]

[0002] 2. Description of the Related Art Fuel reformers are known that utilize a fuel reforming catalyst and the heat of exhaust gas to produce a reformed gas containing hydrogen from exhaust gas containing water and carbon dioxide.

[0003] For example, a technology has been disclosed in which a fuel reforming device including a fuel sprayer, a fuel evaporator, and a fuel reforming catalyst is placed within the exhaust gas recirculation system, the temperature of the fuel reforming catalyst is detected, and the amount of oxygen in the exhaust gas, the amount of exhaust gas, and the amount of fuel supplied to the fuel reforming device are adjusted according to that temperature, thereby controlling the molar ratio of oxygen to carbon in the fuel at the inlet of the fuel reforming catalyst (Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-133253 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, in the prior art, it is said that an air supply device is used as a means for changing the oxygen concentration, but no specific method for adjusting the oxygen concentration is disclosed.

[0006] In addition, because exhaust pulsation and pressure loss generally cause the pressure inside the exhaust pipe to be higher than atmospheric pressure, it is necessary to pressurize the air using a pump or other device to introduce it into the EGR path, which poses a problem of power loss in the pump or other device. [Means for solving the problem]

[0007] One aspect of the present invention is a fuel reforming device that reforms fuel in an internal combustion engine to produce hydrogen, and is characterized in that it comprises a fuel reforming catalyst arranged in an EGR path that returns a portion of the exhaust gas of the internal combustion engine downstream of an intake throttle installed in an intake pipe, an air supply path that connects upstream of the intake throttle of the internal combustion engine to upstream of the fuel reforming catalyst, an EGR flow control valve provided in the EGR path between the exhaust pipe of the internal combustion engine and the connection point with the air supply path, and an air flow control valve provided in the air supply path, and the flow rates of fuel, exhaust gas, and air are adjusted by the EGR flow control valve and the air flow control valve and are supplied to the fuel reforming catalyst.

[0008] Another aspect of the present invention is a fuel reforming device that reforms fuel in an internal combustion engine to produce hydrogen, and includes: a fuel reforming catalyst arranged in an EGR path that returns a portion of the exhaust gas from the internal combustion engine downstream of a first intake throttle and upstream of a second intake throttle installed in an intake pipe; an air supply path that connects downstream of a connection between the intake pipe and the EGR path and upstream of the second intake throttle to upstream of the fuel reforming catalyst; an EGR flow control valve provided in the EGR path between the exhaust pipe of the internal combustion engine and the connection with the air supply path; and an air flow control valve provided in the air supply path, wherein the flow rates are adjusted by the EGR flow control valve and the air flow control valve and the fuel, exhaust gas, and air are supplied to the fuel reforming catalyst.

[0009] Here, it is preferable that the fuel supply means for supplying fuel to the fuel reforming catalyst includes an ejector capable of sucking air and supplying the air from the air supply path to the EGR path.

[0010] Furthermore, it is preferable that the internal combustion engine is a turbocharged internal combustion engine equipped with a compressor and a turbine, the exhaust gas intake port to the EGR path is located downstream of the turbine, the return position of the EGR path to the intake pipe is located upstream of the compressor, and air containing reformed gas is taken out from downstream of the compressor and supplied upstream of the fuel reforming catalyst via the air flow control valve.

[0011] It is also preferable to have a means for detecting or estimating the temperature of the exhaust gas of the internal combustion engine, and to control the ratio of the air flow rate to the supply fuel flow rate supplied to the fuel reforming catalyst so that the higher the temperature of the exhaust gas, the smaller the ratio.

[0012] It is also preferable to have a means for detecting or estimating the temperature of the fuel reforming catalyst, and to control the ratio of the air flow rate to the supply fuel flow rate supplied to the fuel reforming catalyst so that the higher the temperature of the fuel reforming catalyst, the smaller the ratio.

[0013] It is also preferable to control the ratio of the air flow rate to the supplied fuel flow rate so that the temperature of the fuel reforming catalyst is constant.

[0014] It is also preferable to perform control so as not to allow exhaust gas to flow into the fuel reforming catalyst during at least one of the start-up and warm-up processes of the internal combustion engine.

[0015] It is also preferable that the fuel supplied to the fuel reforming catalyst is ammonia.

[0016] It is preferable that an intake port for exhaust gas into the EGR path is disposed downstream of a three-way catalyst provided in the internal combustion engine, and that the mixture supplied to the internal combustion engine is controlled to be stoichiometric.

[0017] Another aspect of the present invention is an internal combustion engine comprising the above-described fuel reformer. [Effects of the Invention]

[0018] According to the present invention, it is possible to appropriately adjust the oxygen concentration in a fuel reformer and an internal combustion engine equipped with the same. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a diagram showing the configuration of a fuel reformer and an internal combustion engine equipped with the same according to a first embodiment. [Figure 2] FIG. 4 is a diagram showing the relationship between the temperature of exhaust gas and the air / fuel flow ratio in the embodiment of the present invention. [Figure 3] FIG. 10 is a diagram showing the configuration of a fuel reformer and an internal combustion engine equipped with the same according to a second embodiment. [Figure 4] FIG. 10 is a diagram showing the configuration of a fuel reformer and an internal combustion engine equipped with the same according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0020] 1, the fuel reformer 100 in the first embodiment includes an intake pipe 8, an intake throttle 10, a fuel ejector 12, a three-way catalyst 14, an EGR path 15, an EGR flow rate adjustment valve 16, a reformed fuel ejector 18, a fuel reformer 20, a cooler 22, an EGR valve 24, an air supply path 25, an air flow rate adjustment valve 26, a temperature sensor 28, and a control unit 30. The fuel reformer 100 is used in combination with an internal combustion engine 200 such as an internal combustion engine.

[0021] The intake pipe 8 is a pipe for supplying air and fuel to the internal combustion engine 200. An intake throttle 10 and a fuel ejector 12 are provided in the intake pipe 8. The intake throttle 10 is a throttle for sending air into a combustion chamber of the internal combustion engine 200. The opening of the intake throttle 10 is controlled by the control unit 30 in accordance with the load on the internal combustion engine 200, which is determined by factors such as the user's accelerator operation. The fuel ejector 12 is provided as a means for supplying fuel to be burned in the combustion chamber of the internal combustion engine 200. The amount of fuel supplied from the fuel ejector 12 is controlled by the control unit 30 in accordance with the load on the internal combustion engine 200, which is determined by factors such as the user's accelerator operation.

[0022] A mixture of air supplied from an intake throttle 10 and fuel supplied from a fuel ejector 12 is supplied to a combustion chamber of the internal combustion engine 200. In the internal combustion engine 200, the mixture of air and fuel is compressed by a piston, and the mixture is burned by spark ignition or the like. The piston is driven by the combustion, and power is output from the internal combustion engine 200. Exhaust gas after combustion is discharged from the internal combustion engine 200 to a three-way catalyst 14.

[0023] The three-way catalyst 14 is provided to remove harmful substances contained in exhaust gas, such as hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxides (NOx). The three-way catalyst 14 is installed midway through the exhaust pipe of the internal combustion engine 200. The three-way catalyst 14 includes a catalyst using, for example, platinum, palladium, or rhodium. The hydrocarbons contained in the exhaust gas are oxidized to water and carbon dioxide, the carbon monoxide is oxidized to carbon dioxide, and the nitrogen oxides are reduced to nitrogen. The three-way catalyst 14 is manufactured by a washcoat method in which a catalyst support formed from ceramic or the like is immersed in a precious metal salt solution to fix (support) precious metal particles on the surface of the catalyst support, or a coating method in which precious metal particles are applied to a catalyst substrate.

[0024] The EGR path 15 is a path consisting of piping for recirculating exhaust gas emitted from the internal combustion engine 200 to the intake pipe 8 in an exhaust gas recirculation system (EGR). The EGR path 15 is composed of piping that connects the downstream side of the three-way catalyst 14 to the intake pipe 8. The EGR path 15 is provided with an EGR flow rate adjustment valve 16, a fuel reformer 20, a cooler 22, and an EGR valve 24.

[0025] The EGR flow rate adjustment valve 16 is provided to adjust the flow rate of exhaust gas recirculated in the EGR. The EGR aims to reduce nitrogen oxides in the exhaust gas and to suppress fuel consumption during low loads. The EGR flow rate adjustment valve 16 is located downstream of the three-way catalyst 14 in the exhaust system of the internal combustion engine 200.

[0026] The reformed fuel ejector 18 is provided as a means for supplying fuel used in the fuel reformer 20. The reformed fuel ejector 18 is disposed within the exhaust gas recirculation system. The fuel supplied from the reformed fuel ejector 18 is, for example, ammonia. The amount of fuel supplied from the reformed fuel ejector 18 is controlled by the control unit 30.

[0027] The fuel reformer 20 includes a fuel reforming catalyst. The fuel reformer 20 is disposed within the exhaust gas recirculation system. The fuel reformer 20 utilizes the fuel reforming catalyst and heat from the exhaust gas to generate a reformed gas containing hydrogen from exhaust gas containing water and carbon dioxide, or from exhaust gas and fuel. The fuel reforming catalyst preferably contains at least one metal selected from platinum (Pt), rhodium (Rh), palladium (Pd), nickel (Ni), copper (Cu), and cobalt (Co). However, the catalyst component may be selected from materials appropriate for the type of fuel to be treated. The fuel reforming catalyst preferably contains an oxide of at least one metal selected from aluminum (Al), cerium (Ce), zirconium (Zr), lanthanum (La), neodymium (Nd), niobium (Nb), silicon (Si), magnesium (Mg), and calcium (Ca) as a support or promoter component. For example, a catalyst is used which uses rhodium (Rh) as a catalytic component and an oxide containing cerium (Ce) and lanthanum (La) as a support.

[0028] The cooler 22 is a means for cooling the reformed gas produced by the reforming process in the fuel reformer 20. The cooler 22 can be an air-cooled or water-cooled cooling system.

[0029] The EGR valve 24 is provided as a means for supplying the reformed gas to the piping of the intake system of the internal combustion engine 200. The EGR valve 24 is disposed downstream of the intake throttle 10 in the piping of the intake system of the internal combustion engine 200. By opening the EGR valve 24, the reformed gas generated in the fuel reformer 20 is supplied into the piping of the intake system.

[0030] The air supply path 25 is a path consisting of piping for supplying air to the EGR path 15. The air supply path 25 is composed of piping that connects the intake pipe 8 to the EGR path 15. An air flow rate adjustment valve 26 is provided in the air supply path 25. The air flow rate adjustment valve 26 is a valve provided for supplying air to the EGR piping. The air flow rate adjustment valve 26 is provided midway in the piping that connects the upstream side of the intake throttle 10 in the piping of the intake system of the internal combustion engine 200 to the upstream side of the reformed fuel ejector 18 in the piping of the EGR system.

[0031] In the fuel reformer 100, ammonia is injected as reformed fuel from a reformed fuel ejector 18 into exhaust gas introduced into the EGR piping via an EGR flow rate adjustment valve 16, and the ammonia is supplied to a fuel reformer 20. This allows a portion of the ammonia to be decomposed into hydrogen in the fuel reformer 20 and supplied to an internal combustion engine 200. By generating hydrogen in the fuel reformer 20, it is possible to assist the combustion of ammonia, which has a slow combustion rate.

[0032] Here, the decomposition of ammonia into hydrogen is an endothermic reaction, so the higher the temperature of the exhaust gas, the easier it is to generate hydrogen in the fuel reformer 20. On the other hand, depending on the operating conditions of the internal combustion engine 200, the temperature of the exhaust gas may become low, resulting in insufficient generation of hydrogen in the fuel reformer 20. In such cases, the opening of the air flow control valve 26 is adjusted to supply air to the fuel reformer 20 through the air supply pipe. A portion of the ammonia, which is the reformed fuel, is oxidized by the air, making it possible to make up for the heat that is insufficient from the exhaust gas alone.

[0033] In the fuel reformer 100 of this embodiment, air can be supplied to the EGR piping at an appropriate flow rate by adjusting the openings of the air flow control valve 26 and the EGR flow control valve 16 so that the pressure in the EGR piping downstream of the EGR flow control valve 16 is lower than the pressure (atmospheric pressure) upstream of the intake throttle 10 in the piping of the intake system of the internal combustion engine 200. That is, since the pressure in an exhaust pipe is generally equal to or higher than atmospheric pressure, adjusting the opening of the EGR flow control valve 16 reduces the pressure in the EGR piping below atmospheric pressure, thereby allowing atmospheric air to be supplied to the EGR piping. Furthermore, although air can be supplied by opening the air flow control valve 26, the opening of the EGR flow control valve 16 can be reduced to further increase the air flow rate.

[0034] As a method for controlling the air flow rate, the amount of air supplied into the EGR piping can be controlled according to the exhaust gas temperature. The exhaust gas temperature is measured by a temperature sensor 28 provided in the piping of the exhaust system of the internal combustion engine 200. When the control unit 30 receives the exhaust gas temperature measured by the temperature sensor 28, if the temperature is equal to or higher than a predetermined exhaust gas temperature reference value, the control unit 30 closes the air flow rate control valve 26 to reform ammonia without supplying air into the EGR piping. If the temperature is lower than the exhaust gas temperature reference value, as shown in FIG. 2, the control unit 30 adjusts the apertures of the air flow rate control valve 26 and the EGR flow rate control valve 16 so that air and reformed fuel are supplied into the EGR piping at flow rates corresponding to the decrease in exhaust gas temperature. In other words, the apertures of the air flow rate control valve 26 and the EGR flow rate control valve 16 are controlled so that the air flow rate relative to the ammonia flow rate supplied to the fuel reformer 20 increases as the exhaust gas temperature decreases.

[0035] This allows stable hydrogen production while adjusting the flow rates of exhaust gas and air according to the temperature of the exhaust gas.

[0036] As another method for controlling the air flow rate, the catalyst temperature in the fuel reformer 20 can be used as a guide. The temperature of the fuel reforming catalyst is measured by a temperature sensor 28 provided in the fuel reformer 20. When the control unit 30 receives the temperature of the fuel reforming catalyst measured by the temperature sensor 28, if the temperature is equal to or higher than a predetermined catalyst temperature reference value, the control unit 30 adjusts the apertures of the air flow rate control valve 26 and the EGR flow rate control valve 16 so as to decrease the ratio of the air flow rate to the ammonia flow rate. If the temperature of the fuel reforming catalyst is less than the catalyst temperature reference value, the control unit 30 adjusts the apertures of the air flow rate control valve 26 and the EGR flow rate control valve 16 so as to increase the ratio of the air flow rate to the ammonia flow rate.

[0037] This allows stable hydrogen generation while controlling the temperature of the fuel reforming catalyst to approach the catalyst temperature reference value.

[0038] Furthermore, there is a possibility that combustion may become unstable or the temperature of the exhaust gas may become low during the cold start and warm-up process of the internal combustion engine 200. Therefore, by closing the EGR flow control valve 16 to prevent the exhaust gas from being recirculated and supplying only air and ammonia to the fuel reformer 20, stable hydrogen generation and engine operation can be achieved.

[0039] Furthermore, by operating the EGR system with the exhaust gas intake into the piping downstream of the three-way catalyst 14 and controlling the air-fuel mixture stoichiometrically, the unburned fuel in the exhaust gas can be oxidized just enough, and the temperature of the exhaust gas can be increased. This is suitable for fuel reforming in the fuel reformer 20.

[0040] In addition to the ammonia supplied to the fuel reformer 20, ammonia may be supplied directly to the intake system of the internal combustion engine 200 without being reformed. In this case, a fuel ejector 12 for supplying ammonia to piping on the intake side of the internal combustion engine 200 may be provided.

[0041] 3 shows the configuration of a fuel reformer 102 according to the second embodiment. In place of the reformed fuel ejector 18, the fuel reformer 102 is provided with a reformed fuel ejector 32 equipped with an ejector capable of sucking air.

[0042] In the ejector of the reformed fuel ejector 32, negative pressure is generated by flowing ammonia, which is the fuel, at high speed, and it is possible to supply air into the piping even when the EGR piping pressure is higher than the air pressure (atmospheric pressure). In this case, air is supplied at a constant ratio to the flow rate of ammonia.

[0043] The ratio of the flow rate of exhaust gas recirculated by the EGR to the flow rate of air can be adjusted by changing the flow rate of the recirculated exhaust gas. The flow rate of exhaust gas can be adjusted by providing an EGR flow rate adjustment valve 16, as in the fuel reformer 100, and adjusting the aperture of the EGR flow rate adjustment valve 16. In addition, in a configuration such as the fuel reformer 102, in which an on-off valve (shutoff valve) 34 without a flow rate adjustment function is provided instead of the EGR flow rate adjustment valve 16, the ratio of the flow rates of exhaust gas and air can also be adjusted by adjusting the aperture of the EGR valve 24 provided downstream of the fuel reformer 20. That is, if the air flow rate is to be reduced relative to the exhaust gas flow rate by the EGR, the aperture of the EGR valve 24 can be increased to increase the exhaust gas flow rate of the EGR. If the air flow rate is to be increased relative to the exhaust gas flow rate by the EGR, the aperture of the EGR valve 24 can be decreased to reduce the exhaust gas flow rate of the EGR.

[0044] The air supply pipe may be provided with an air flow rate adjusting valve 26. By changing the opening of the air flow rate adjusting valve 26, it becomes possible to change the air flow rate relative to the flow rate of the fuel (ammonia).

[0045] 4 shows the configuration of a fuel reformer 104 in the third embodiment. The fuel reformer 104 shows a configuration in which the fuel reformer 104 is applied to an internal combustion engine 200 equipped with an exhaust turbocharging mechanism.

[0046] In the exhaust turbocharging mechanism, an intake compressor 36 is disposed between a first intake throttle 10a and a second intake throttle 10b provided in the piping of the intake system of the internal combustion engine 200, and an exhaust turbine 38 is disposed on the exhaust side of the internal combustion engine 200. In this configuration, the intake compressor 36 is driven by the exhaust turbine 38, thereby increasing the intake pressure of the air downstream of the first intake throttle 10a.

[0047] The EGR piping connects the downstream side of the exhaust turbine 38 on the exhaust side of the internal combustion engine 200 to the upstream side of the intake compressor 36 on the intake side. In addition, the air supply pipe to the fuel reformer 20 is connected between the intake compressor 36 on the intake side and a second intake throttle 10b provided downstream of it. An air flow control valve 26 is provided in the path of the air supply pipe. The air flow rate can be controlled by adjusting the opening of the air flow control valve 26.

[0048] In the fuel reformer 104, by driving the intake compressor 36 on the intake side, the pressure downstream of the intake compressor 36 in the intake system piping can be increased to be higher than the pressure in the EGR piping, making it possible to supply air to the fuel reformer 20. However, since the reformed gas containing ammonia and hydrogen as fuel is supplied upstream of the intake compressor 36, part of the mixture of air and reformed gas is supplied to the fuel reformer 20 through the air supply pipe.

[0049] As described above, the fuel reformer of the above embodiment can adjust the amount of oxygen, exhaust gas, and fuel supplied to the fuel reformer in accordance with the exhaust gas temperature and the reforming catalyst temperature, as well as the amount of air supplied, thereby enabling more responsive and rapid control.

[0050] [Configuration of the present invention] [Configuration 1] A fuel reformer for generating hydrogen by reforming fuel in an internal combustion engine, a fuel reforming catalyst disposed in an EGR path that returns a portion of the exhaust gas from the internal combustion engine downstream of an intake throttle disposed in an intake pipe; an air supply path connecting an upstream of the intake throttle of the internal combustion engine to an upstream of the fuel reforming catalyst; an EGR flow rate adjustment valve provided in the EGR path between an exhaust pipe of the internal combustion engine and a connection portion with the air supply path; an air flow rate adjusting valve provided in the air supply path; Equipped with A fuel reforming device, characterized in that the fuel, exhaust gas and air are supplied to the fuel reforming catalyst with their flow rates adjusted by the EGR flow rate adjustment valve and the air flow rate adjustment valve. [Configuration 2] A fuel reformer for generating hydrogen by reforming fuel in an internal combustion engine, a fuel reforming catalyst disposed in an EGR path that returns a portion of the exhaust gas from the internal combustion engine downstream of a first intake throttle and upstream of a second intake throttle disposed in an intake pipe; an air supply path that connects a downstream portion of a connection portion between the intake pipe and the EGR path and an upstream portion of the second intake throttle to a location upstream of the fuel reforming catalyst; an EGR flow rate adjustment valve provided in the EGR path between an exhaust pipe of the internal combustion engine and a connection portion with the air supply path; an air flow rate adjusting valve provided in the air supply path; Equipped with A fuel reforming device, characterized in that the fuel, exhaust gas and air are supplied to the fuel reforming catalyst with their flow rates adjusted by the EGR flow rate adjustment valve and the air flow rate adjustment valve. [Configuration 3] The fuel reformer according to the first or second aspect, A fuel reforming device characterized in that the fuel supply means for supplying fuel to the fuel reforming catalyst includes an ejector capable of sucking air and supplying the air from the air supply path to the EGR path. [Configuration 4] The fuel reformer according to configuration 2, the internal combustion engine is a supercharged internal combustion engine equipped with a compressor and a turbine, an intake port for exhaust gas into the EGR path is provided downstream of the turbine; a return position of the EGR path to the intake pipe is provided upstream of the compressor, A fuel reforming device, characterized in that air containing reformed gas is taken out from downstream of said compressor and supplied to upstream of said fuel reforming catalyst via said air flow rate adjusting valve. [Configuration 5] A fuel reformer according to any one of configurations 1 to 4, means for detecting or estimating the temperature of exhaust gas from the internal combustion engine; A fuel reforming device characterized in that the ratio of the air flow rate to the supply fuel flow rate supplied to the fuel reforming catalyst is controlled so as to decrease as the temperature of the exhaust gas increases. [Configuration 6] A fuel reformer according to any one of configurations 1 to 4, a means for detecting or estimating the temperature of the fuel reforming catalyst; A fuel reforming device characterized in that the ratio of the air flow rate to the supply fuel flow rate supplied to the fuel reforming catalyst is controlled so as to decrease as the temperature of the fuel reforming catalyst increases. [Configuration 7] 7. The fuel reformer according to claim 6, A fuel reforming device characterized in that the ratio of air flow rate to the supplied fuel flow rate is controlled so that the temperature of the fuel reforming catalyst is kept constant. [Configuration 8] A fuel reformer according to any one of configurations 1 to 7, A fuel reforming device characterized by controlling so as not to allow exhaust gas to flow into said fuel reforming catalyst during at least one of the start-up and warm-up processes of said internal combustion engine. [Configuration 9] A fuel reformer according to any one of configurations 1 to 8, 2. A fuel reforming device according to claim 1, wherein the fuel supplied to the fuel reforming catalyst is ammonia. [Configuration 10] A fuel reformer according to any one of configurations 1 to 9, an intake port for exhaust gas into the EGR path is disposed downstream of a three-way catalyst provided in the internal combustion engine; A fuel reformer characterized in that the air-fuel mixture supplied to the internal combustion engine is controlled to have a stoichiometric ratio. [Configuration 11] 11. An internal combustion engine comprising the fuel reformer according to any one of aspects 1 to 10. [Explanation of symbols]

[0051] 8 intake pipe, 10 intake throttle, 12 fuel ejector, 14 three-way catalyst, 15 EGR path, 16 EGR flow control valve, 18 reformed fuel ejector, 20 fuel reformer, 22 cooler, 24 EGR valve, 25 air supply path, 26 air flow control valve, 28 temperature sensor, 30 control unit, 32 reformed fuel ejector, 34 on-off valve (shutoff valve), 36 intake compressor, 38 exhaust turbine, 100, 102, 104 fuel reformer, 200 internal combustion engine.

Claims

1. A fuel reformer for generating hydrogen by reforming fuel in an internal combustion engine, a fuel reforming catalyst disposed in an EGR path that returns a portion of the exhaust gas from the internal combustion engine downstream of an intake throttle disposed in an intake pipe; an air supply path connecting an upstream of the intake throttle of the internal combustion engine to an upstream of the fuel reforming catalyst; an EGR flow rate adjustment valve provided in the EGR path between an exhaust pipe of the internal combustion engine and a connection portion with the air supply path; an air flow rate adjusting valve provided in the air supply path; Equipped with A fuel reforming device, characterized in that the fuel, exhaust gas and air are supplied to the fuel reforming catalyst with their flow rates adjusted by the EGR flow adjustment valve and the air flow adjustment valve.

2. A fuel reformer for generating hydrogen by reforming fuel in an internal combustion engine, a fuel reforming catalyst disposed in an EGR path that returns a portion of the exhaust gas from the internal combustion engine downstream of a first intake throttle and upstream of a second intake throttle disposed in an intake pipe; an air supply path connecting a downstream portion of a connection portion between the intake pipe and the EGR path and an upstream portion of the second intake throttle to a location upstream of the fuel reforming catalyst; an EGR flow rate adjustment valve provided in the EGR path between an exhaust pipe of the internal combustion engine and a connection portion with the air supply path; an air flow rate adjusting valve provided in the air supply path; Equipped with A fuel reforming device, characterized in that the fuel, exhaust gas and air are supplied to the fuel reforming catalyst with their flow rates adjusted by the EGR flow adjustment valve and the air flow adjustment valve.

3. 3. The fuel reformer according to claim 1 or 2, A fuel reforming device, wherein the fuel supply means for supplying fuel to the fuel reforming catalyst includes an ejector capable of sucking air and supplying the air from the air supply path to the EGR path.

4. 3. The fuel reformer according to claim 2, the internal combustion engine is a supercharged internal combustion engine equipped with a compressor and a turbine, an exhaust gas intake port for the EGR path is provided downstream of the turbine; a recirculation position of the EGR path to the intake pipe is provided upstream of the compressor, A fuel reforming device, characterized in that air containing reformed gas is taken out from downstream of said compressor and supplied to upstream of said fuel reforming catalyst via said air flow rate adjusting valve.

5. 3. The fuel reformer according to claim 1 or 2, means for detecting or estimating the temperature of exhaust gas from the internal combustion engine; A fuel reforming device characterized in that the ratio of the air flow rate to the supply fuel flow rate supplied to the fuel reforming catalyst is controlled so as to decrease as the temperature of the exhaust gas increases.

6. 3. The fuel reformer according to claim 1 or 2, a means for detecting or estimating the temperature of the fuel reforming catalyst; A fuel reforming device characterized in that the ratio of the air flow rate to the supply fuel flow rate supplied to the fuel reforming catalyst is controlled so as to decrease as the temperature of the fuel reforming catalyst increases.

7. 7. A fuel reformer according to claim 6, A fuel reforming device characterized in that the ratio of the air flow rate to the supplied fuel flow rate is controlled so that the temperature of the fuel reforming catalyst is kept constant.

8. 3. The fuel reformer according to claim 1 or 2, A fuel reforming device characterized by controlling so as not to allow exhaust gas to flow into said fuel reforming catalyst during at least one of the start-up and warm-up processes of said internal combustion engine.

9. 3. The fuel reformer according to claim 1 or 2, 2. A fuel reforming device according to claim 1, wherein the fuel supplied to the fuel reforming catalyst is ammonia.

10. 3. The fuel reformer according to claim 1 or 2, an intake port for exhaust gas into the EGR path is disposed downstream of a three-way catalyst provided in the internal combustion engine; A fuel reformer characterized in that the air-fuel mixture supplied to the internal combustion engine is controlled to have a stoichiometric ratio.

11. An internal combustion engine comprising the fuel reformer according to claim 1 or 2.

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