Fuel reforming system

Abstract

To provide a technology for reforming gas containing fuel without depending on an operating state of an internal combustion engine, in a fuel reforming system provided in an intake system of the internal combustion engine.SOLUTION: A fuel reforming system provided in an intake system of an internal combustion engine comprises a flow path member, a fuel injection device, a reforming catalyst, and a light source device. The flow path member forms an intake flow path to the internal combustion engine. The fuel injection device is configured to inject fuel into the intake flow path. The reforming catalyst is configured to reform gas containing the injected fuel downstream of the fuel injection device in the intake flow path. The light source device is configured to emit a light flux including infrared rays toward the reforming catalyst.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a fuel reforming system provided in the intake system of an internal combustion engine. [Background technology]

[0002] For example, Patent Document 1 describes a reformed gas engine system that includes an evaporator, a heat exchanger, and a reforming catalyst. In the system described in Patent Document 1, the evaporator evaporates fuel and supplies it to the reforming catalyst. The heat exchanger heats the reforming catalyst. Then, while heated by the heat exchanger, the reforming catalyst reforms the gas containing fuel supplied by the evaporator. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-228610 Summary of the Invention [Problem to be solved by the invention]

[0004] In the system described in Patent Document 1, in order for the reforming catalyst to reform the gas containing fuel, the reforming catalyst needs to be heated to an activation temperature. However, in the system described in Patent Document 1, the heat exchanger is configured to heat the reforming catalyst by using thermal energy of exhaust gas from the internal combustion engine. For this reason, it may be difficult for the heat exchanger to heat the reforming catalyst, for example, in a state where no exhaust gas is generated, such as before the internal combustion engine starts, or in a state where the temperature of the exhaust gas is low, such as immediately after the internal combustion engine starts. In other words, depending on the operating state of the internal combustion engine, it may be difficult for the heat exchanger to heat the reforming catalyst. If the reforming catalyst is difficult to heat, it becomes difficult to reform the gas containing fuel.

[0005] One aspect of the present disclosure provides a technology for making it easier to reform a gas containing fuel in a fuel reforming system provided in an intake system of an internal combustion engine, regardless of the operating state of the internal combustion engine. [Means for solving the problem]

[0006] One aspect of the present disclosure is a fuel reforming system provided in an intake system of an internal combustion engine, comprising a flow path member, a fuel injection device, a reforming catalyst, and a light source device. The flow path member forms an intake flow path to the internal combustion engine. The fuel injection device is configured to inject fuel into the intake flow path. The reforming catalyst is configured to reform a gas containing the injected fuel downstream of the fuel injection device in the intake flow path. The light source device is configured to emit a light beam including infrared rays toward the reforming catalyst. With this configuration, the fuel reforming system can easily reform the gas containing fuel regardless of the operating state of the internal combustion engine.

[0007] In one aspect of the present disclosure, the reforming catalyst may have a plurality of cells. The plurality of cells are a plurality of cylindrical portions extending in the flow direction of the intake air flow passage. The light source device may be configured to emit a light beam such that at least some of the plurality of light rays constituting the light beam intersect with the inner surfaces of the plurality of cells. With this configuration, the fuel reforming system can more easily reform a gas containing fuel, regardless of the operating state of the internal combustion engine.

[0008] In one aspect of the present disclosure, the light source device may be configured to emit a light flux in which a plurality of light rays converge. The light source device may also be disposed so that a region of the light flux in which the plurality of light rays converge does not overlap with a surface of the outer surfaces of the plurality of cells that faces the light source device in the flow direction of the intake air flow passage. This configuration can suppress deterioration of the reforming catalyst in the fuel reforming system.

[0009] In one aspect of the present disclosure, the light source device may be configured to emit a light beam in which a plurality of light rays are parallel to each other, and the light source device may be disposed such that the emission direction of the light beam intersects with the inner surfaces of the plurality of cells.

[0010] In one aspect of the present disclosure, the light source device may be configured to emit a light flux from the upstream side of the reforming catalyst. With this configuration, compared to when the light source device is configured to emit a light flux from the downstream side of the reforming catalyst, it is possible to prevent the temperature of the gas that has passed through the reforming catalyst from becoming too high while maintaining the effect of facilitating reforming of the gas that contains fuel, regardless of the operating state of the internal combustion engine.

[0011] In one aspect of the present disclosure, the light source device may be a halogen lamp heater. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic diagram showing an intake system and an exhaust system of an internal combustion engine of a vehicle; [Figure 2] FIG. 1 is a block diagram showing the configuration of a fuel reforming system. [Figure 3] 1 is a schematic diagram of a reforming catalyst whose outer periphery is covered with a support mat, viewed from the upstream side. [Figure 4] FIG. 2 is a schematic diagram for explaining how a light ray travels within a reforming catalyst. [Figure 5] 4 is a flowchart illustrating a fuel reforming process. [Figure 6] 6 is a flowchart continuing from FIG. 5. [Figure 7] FIG. 10 is a schematic diagram for explaining a first modified example of the position of the light source device. [Figure 8] FIG. 10 is a schematic diagram illustrating a second modified example of the position of the light source device. [Figure 9] FIG. 10 is a schematic diagram for explaining a first modified example of the directions of a plurality of light rays. [Figure 10] FIG. 10 is a schematic diagram for explaining a second modified example of the directions of a plurality of light rays. [Figure 11]1 is a schematic diagram of a reformulated fuel system having multiple light source devices. [Figure 12] FIG. 10 is a schematic diagram for explaining a modification of the position of the fuel injection device. [Figure 13] FIG. 1 is a schematic diagram of a reformed fuel system equipped with a stirring member. [Figure 14] FIG. 4 is a perspective view of the stirring member as viewed from the downstream side. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings.

[0014] [1. Configuration] [1-1. Configuration of intake and exhaust systems] FIG. 1 shows an intake system 2 and an exhaust system 6 of an internal combustion engine 1 of a vehicle. The intake system 2 supplies atmospheric air to the internal combustion engine 1. The exhaust system 6 discharges exhaust gas from the internal combustion engine 1 to the outside of the vehicle. In the drawing, the flow of gas including air in the intake system 2 is indicated by open arrows. Furthermore, the flow of exhaust gas in the exhaust system 6 is indicated by filled arrows. Note that in a vehicle, the internal combustion engine 1 may be used, for example, for driving the vehicle or for generating electricity.

[0015] The intake system 2 includes an intake passage member 30, a supercharger 40, and a fuel reforming system 50.

[0016] The intake passage member 30 is a member that forms the intake passage 31. The intake passage 31 is a passage that supplies air in the atmosphere to the internal combustion engine 1.

[0017] The intake passage 31 includes a main passage 311 and a branch passage 312. The main passage 311 is a passage that continues from an intake port (not shown) to the internal combustion engine 1. Specifically, the main passage 311 continues from the intake port to the main combustion chamber 11 of the internal combustion engine 1. The intake port is an opening configured to take in air from the atmosphere. The branch passage 312 is a passage that branches off from the main passage 311 and continues to the internal combustion engine 1. Specifically, the branch passage 312 branches off from the main passage 311 and continues to the auxiliary combustion chamber 12 of the internal combustion engine 1. The branch position of the branch passage 312 from the main passage 311 is downstream of the turbocharger 40.

[0018] Both the main combustion chamber 11 and the auxiliary combustion chamber 12 are chambers where combustion takes place. The main combustion chamber 11 is larger than the auxiliary combustion chamber 12. The main combustion chamber 11 and the auxiliary combustion chamber 12 are connected to each other via a communication hole 13, and are configured so that flames generated in the auxiliary combustion chamber 12 are ejected from the communication hole 13 into the main combustion chamber 11.

[0019] The supercharger 40 is configured to compress the air flowing through the intake passage 31 and send it downstream. The supercharger 40 of this embodiment is a turbocharger. The turbocharger uses the pressure of exhaust gas to rotate a turbine, and compresses the air flowing through the main passage 311 with a compressor connected to the turbine.

[0020] The fuel reforming system 50 is applied to the branch flow path 312. As will be described in detail later, the fuel reforming system 50 is configured to generate a reformed gas containing hydrogen. The reformed gas generated by the fuel reforming system 50 is supplied from the branch flow path 312 to the auxiliary combustion chamber 12 of the internal combustion engine 1. A flame generated by combustion of the reformed gas in the auxiliary combustion chamber 12 is ejected into the main combustion chamber 11, and combustion takes place in the main combustion chamber 11, thereby achieving lean combustion in the main combustion chamber 11. Therefore, the combustion efficiency of the internal combustion engine 1 is improved compared to when the reformed gas is not supplied to the internal combustion engine 1.

[0021] The exhaust system 6 includes an exhaust flow path member 70 and a purification catalyst 80.

[0022] The exhaust flow path member 70 is a member that forms an exhaust flow path 71. The exhaust flow path 71 is a flow path that discharges exhaust gas from the internal combustion engine 1 to the outside of the vehicle. The exhaust flow path 71 continues from the internal combustion engine 1 to an exhaust port (not shown). Specifically, the exhaust flow path 71 continues from the main combustion chamber 11 of the internal combustion engine 1 to the exhaust port. The exhaust port is an opening that is open to the atmosphere. In this embodiment, since the supercharger 40 is a turbocharger, the exhaust flow path 71 passes through the turbine of the turbocharger.

[0023] The purification catalyst 80 is configured to purify the exhaust gas flowing through the exhaust flow path 71. The purification catalyst 80 purifies the exhaust gas by the catalytic components carried inside reacting with harmful components in the exhaust gas or by adsorbing the harmful components.

[0024] The exhaust system 6 may further include, for example, a silencer downstream of the purification catalyst 80. The silencer is configured to reduce noise caused by exhaust gases.

[0025] [1-2. Configuration of fuel reforming system] The fuel reforming system 50 will be described in further detail with reference to Figures 2 to 4. The fuel reforming system 50 is provided in the intake system 2 of the internal combustion engine 1. The fuel reforming system 50 may be supplied with power from, for example, a drive battery of the vehicle, or from an auxiliary battery of the vehicle.

[0026] As shown in FIG. 2, the fuel reforming system 50 includes a reforming flow path member 51, a fuel injection device 52, a reforming catalyst 53, a retaining mat 54, a light source device 55, a heat exchanger 56, a first temperature sensor 57A, a second temperature sensor 57B, a gas analyzer 58, and a control unit 59.

[0027] The reforming flow path member 51 constitutes a part of the intake flow path member 30 described above. That is, the reforming flow path member 51 forms a part of the intake flow path 31. Specifically, the reforming flow path member 51 forms a part of the branch flow path 312. The reforming flow path member 51 is tubular. The reforming flow path member 51 of this embodiment is tubular. The reforming flow path member 51 corresponds to an example of a flow path member.

[0028] The fuel injection device 52 is configured to inject fuel into the branch passage 312. The fuel referred to here is fuel that is compatible with the internal combustion engine 1. A specific example of the fuel that is compatible with the internal combustion engine 1 is gasoline fuel.

[0029] The fuel injector 52 is fixed to the wall of the reforming flow path member 51 so as to be able to inject fuel into the branch flow path 312. The fuel injector 52 is fixed to a position on the wall of the reforming flow path member 51 upstream of the reforming catalyst 53. Specifically, the fuel injector 52 is fixed to a position on the wall of the reforming flow path member 51 facing the reforming catalyst 53 from the upstream side. In other words, the fuel injector 52 faces the reforming catalyst 53 from the upstream side. The fuel injector 52 is configured to inject fuel upstream of the reforming catalyst 53 in the branch flow path 312.

[0030] The activation and deactivation of the fuel injection device 52 is electrically controlled by the control unit 59. When the fuel injection device 52 is activated, the fuel injection device 52 starts injecting fuel. When the fuel injection device 52 is deactivated, the fuel injection device 52 stops injecting fuel.

[0031] The reforming catalyst 53 is a member having a columnar outer shape. In this embodiment, the reforming catalyst 53 is formed to have a columnar outer shape, as shown in Figures 2 and 3, in correspondence with the reforming flow path member 51 having a cylindrical shape.

[0032] The reforming catalyst 53 has a so-called honeycomb structure. The reforming catalyst 53 has a plurality of cells 531. The plurality of cells 531 is a cylindrical portion extending along the central axis X of the reforming catalyst 53. The plurality of cells 531 is, for example, a polygonal cylindrical shape such as a square cylindrical shape or a hexagonal cylindrical shape. The plurality of cells 531 is made of, for example, ceramics. The plurality of cells 531 in this embodiment is made of aluminum oxide (so-called alumina). A catalyst component is supported inside the plurality of cells 531.

[0033] 2, the reforming catalyst 53 is disposed downstream of the fuel injector 52 in the branch flow passage 312. The central axis X of the reforming catalyst 53 is aligned with the flow direction of the branch flow passage 312. Therefore, the multiple cells 531 can be said to be cylindrical portions extending in the flow direction of the branch flow passage 312.

[0034] The reforming catalyst 53 is configured to reform the mixed gas downstream of the fuel injector 52 in the branch flow path 312. The mixed gas is a gas obtained by mixing the fuel injected by the fuel injector 52 and air. The reforming catalyst 53 reforms the mixed gas when the temperature is equal to or higher than the activation temperature Ta. In other words, the reforming catalyst 53 generates a reformed gas, which is a gas obtained by reforming the mixed gas, when the temperature is equal to or higher than the activation temperature Ta. The activation temperature Ta is the temperature at which the catalytic components contained in the reforming catalyst 53 are activated. The activation temperature Ta of the reforming catalyst 53 in this embodiment is 350°C. The reforming catalyst 53 generates a reformed gas containing hydrogen from the fuel contained in the mixed gas and moisture in the air through the action of the catalytic components.

[0035] The retention mat 54 is an elastic member. The retention mat 54 is disposed between the inner surface of the reforming flow path member 51 and the outer surface of the reforming catalyst 53. That is, the reforming catalyst 53 is disposed in the branch flow path 312 with its outer periphery covered by the retention mat 54, as shown in FIG.

[0036] Returning to FIG. 2 , the light source device 55 has a light source and a reflecting mirror (not shown). The light source is configured to emit a plurality of light rays L including infrared rays. The light source in this embodiment is a halogen lamp. That is, the light source device 55 in this embodiment is a halogen lamp heater. The halogen lamp emits a plurality of light rays L including near-infrared rays among infrared rays. The reflecting mirror is configured to reflect at least a portion of the plurality of light rays L emitted from the light source. In the light source device 55, the plurality of light rays L emitted from the light source heads toward the outside of the light source device 55 either directly or after being reflected by the reflecting mirror, and is emitted to the outside of the light source device 55 as a single light beam R. That is, the light source device 55 is configured to emit a light beam R composed of the plurality of light rays L. Since the plurality of light rays L include infrared rays, the light beam R also includes infrared rays.

[0037] In Figure 2 and other figures, the emission direction D of the light beam R is indicated by a solid arrow, and some of the multiple light rays L that make up the light beam R are indicated by dashed arrows. The emission direction D of the light beam R is the direction in which the light beam R is emitted from the light source device 55 to the outside of the light source device 55, and is a direction along the central axis of the light beam R. The light beam R is emitted in one emission direction D as a whole, but the multiple light rays L included in the light beam R do not necessarily have to be parallel to each other. The direction of each of the multiple light rays L within the light beam R can be adjusted by the shape of the mirror surface of the reflecting mirror.

[0038] In this embodiment, the light source device 55 is configured to emit a light flux R in which multiple light rays L converge. That is, the light source device 55 of this embodiment is a so-called converging type. The region in the light flux R where the multiple light rays L converge is hereinafter referred to as a converging region F. The converging region F may be, for example, circular or strip-shaped. In other words, the light source device 55 may be, for example, a so-called point converging type in which the multiple light rays L converge approximately on one point, or a so-called line converging type in which the multiple light rays L converge approximately on one line. After converging toward the converging region F, the multiple light rays L further travel while diverging.

[0039] The light source device 55 is fixed to the wall of the reforming flow path member 51 so as to be able to emit a light flux R toward the reforming catalyst 53. The light source device 55 is fixed to a position on the wall of the reforming flow path member 51 upstream of the reforming catalyst 53. That is, the light source device 55 is configured to emit the light flux R from the upstream side with respect to the reforming catalyst 53. In this embodiment, the light source device 55 is fixed to a portion on the wall of the reforming flow path member 51 that surrounds the reforming catalyst 53 when viewed along the central axis X of the reforming catalyst 53. The light source device 55 is arranged so that the emission direction D of the light flux R intersects with the central axis X of the reforming catalyst 53. In this case, as shown in FIGS. 2 and 7, the position of the light source device 55 in the circumferential direction based on the central axis X of the reforming catalyst 53 is not particularly limited.

[0040] 4, in this embodiment, the light source device 55 is a so-called converging type as described above, and the light source device 55 is arranged so that the convergence region F does not overlap with the upstream surfaces 531a of the multiple cells 531. The upstream surfaces 531a of the multiple cells 531 are the upstream surfaces of the multiple cells 531. Because the light source device 55 is arranged upstream of the reforming catalyst 53, the upstream surfaces 531a of the multiple cells 531 can also be referred to as the surfaces of the multiple cells 531 that face the light source device 55 in the flow direction of the branch flow path 312, among the outer surfaces of the multiple cells 531. Specifically, the light source device 55 is arranged so that the convergence region F is located upstream of the upstream surfaces 531a of the multiple cells 531. When the light source device 55 emits a luminous flux R to the reforming catalyst 53, the multiple light rays L converging in the convergence region F and then diverging further toward the upstream surface 531a. At least some of the light rays L intersect with the inner surfaces 531b of the cells 531. That is, the light source device 55 is configured to emit the light beam R so that at least some of the light rays L intersect with the inner surfaces 531b of the cells 531.

[0041] When the light source device 55 emits a light flux R toward the reforming catalyst 53, the infrared rays contained in the light flux R that reaches the reforming catalyst 53 are absorbed by the reforming catalyst 53, heating the reforming catalyst 53. The intensity of the light flux R is set to an intensity that allows the reforming catalyst 53 to reach at least the activation temperature Ta.

[0042] In particular, in this embodiment, the light beam R is emitted such that at least some of the light beams L intersect with the inner surfaces 531b of the cells 531. At least some of the light beams L enter the cells 531 from a direction intersecting with the inner surfaces 531b of the cells 531. Therefore, the infrared rays contained in the light beam R are more likely to strike the inner surfaces 531b and be more likely to be absorbed by the inner surfaces 531b. In other words, the inner surfaces 531b are more likely to be heated. Furthermore, for example, even if some of the infrared rays are reflected without being absorbed by the inner surfaces 531b of the cells 531 due to the absorbance of the cells 531, the reflected infrared rays strike another part of the same inner surface 531b. If the infrared rays are further reflected from the other part, they strike yet another part of the same inner surface 531b. Therefore, the area of the inner surfaces 531b of the cells 531 that the infrared rays strike is more likely to increase. Consequently, the infrared rays are more likely to be absorbed by the inner surfaces 531b of the cells 531, and the inner surfaces 531b are more likely to be heated. Therefore, the mixed gas is more likely to be reformed by the reforming catalyst 53.

[0043] 2, the activation and deactivation of the light source device 55 is electrically controlled by the control unit 59. When the light source device 55 is activated, the light source device 55 starts emitting a light flux R to the reforming catalyst 53. In other words, the light source device 55 starts heating the reforming catalyst 53. When the light source device 55 is deactivated, the light source device 55 stops emitting the light flux R to the reforming catalyst 53. In other words, the light source device 55 stops heating the reforming catalyst 53.

[0044] The heat exchanger 56 is disposed downstream of the reforming catalyst 53 in the branch flow path 312. The heat exchanger 56 is configured to cool the gas that has passed through the reforming catalyst 53, for example, by heat exchange with a refrigerant. A specific example of the refrigerant is cooling water. The temperature, flow rate, and flow velocity of the refrigerant are set to a temperature, flow rate, and flow velocity that can cool the gas that has passed through the reforming catalyst 53 to a predetermined target temperature Tb. In this embodiment, the target temperature Tb is 120°C.

[0045] The start and stop of the heat exchanger 56 is electrically controlled by the control unit 59. When the heat exchanger 56 is started, the heat exchanger 56 starts circulating the refrigerant. That is, the heat exchanger 56 starts cooling the gas. When the heat exchanger 56 is stopped, the heat exchanger 56 stops circulating the refrigerant. That is, the heat exchanger 56 stops cooling the gas.

[0046] The gas that has passed through the reforming catalyst 53 is cooled by the heat exchanger 56, thereby increasing its density. As a result, the amount of reformed gas containing hydrogen per unit volume increases. By supplying such gas to the internal combustion engine 1, the fuel efficiency of the internal combustion engine 1 is improved.

[0047] The first temperature sensor 57A is disposed inside the reforming catalyst 53. The first temperature sensor 57A is configured to detect a first temperature T1, which is the temperature inside the reforming catalyst 53. The first temperature sensor 57A is configured to output the detected first temperature T1 to the control unit 59.

[0048] The second temperature sensor 57B is disposed adjacent to the downstream side of the heat exchanger 56 in the branch flow path 312. The second temperature sensor 57B is configured to detect a second temperature T2, which is the temperature of the gas immediately after passing through the heat exchanger 56. The second temperature sensor 57B is configured to output the detected second temperature T2 to the control unit 59.

[0049] The gas analyzer 58 is disposed downstream of the reforming catalyst 53 in the branch flow path 312. In this embodiment, the gas analyzer 58 is disposed adjacent to the heat exchanger 56 on the downstream side in the branch flow path 312. Furthermore, in this embodiment, the gas analyzer 58 is disposed at approximately the same position as the second temperature sensor 57B in the flow direction of the branch flow path 312. The gas analyzer 58 is configured to analyze components contained in the gas that has passed through the reforming catalyst 53 (in this embodiment, the gas that has passed through the reforming catalyst 53 and then the heat exchanger 56 immediately after). The gas analyzer 58 is configured to output the analysis results to the control unit 59.

[0050] The control unit 59 is mainly configured with a well-known microcomputer having a CPU and semiconductor memories such as ROM and RAM. The control unit 59 is configured to acquire a first temperature T1 from a first temperature sensor 57A. The control unit 59 is configured to acquire a second temperature T2 from a second temperature sensor 57B. The control unit 59 is configured to acquire gas analysis results from a gas analyzer 58. Although not shown in the figure, the control unit 59 is also configured to acquire a signal indicating whether the internal combustion engine 1 is operating.

[0051] The control unit 59 is configured to control the operation of the fuel injection device 52, the light source device 55, and the heat exchanger 56 based on the first temperature T1, the second temperature T2, and the gas analysis results. Furthermore, for example, the control unit 59 is configured to control whether or not a malfunction lamp (not shown) provided in the vehicle is turned on based on the first temperature T1 and the second temperature T2. The malfunction lamp is a lamp that notifies, for example, the driver or an inspector of the vehicle, of a malfunction in the fuel reforming system 50.

[0052] Each function of the control unit 59 is realized by the CPU executing a program stored in a semiconductor memory. Furthermore, the execution of this program results in the execution of a method corresponding to the program. Note that the control unit 59 may have one microcomputer or multiple microcomputers.

[0053] [2. Processing] The fuel reforming process executed by the control unit 59 will be described with reference to Figures 5 and 6. The fuel reforming process is started when the power of the vehicle is turned on.

[0054] 5, first, in S101, the control unit 59 determines whether the first temperature T1 acquired from the first temperature sensor 57A is equal to or higher than the activation temperature Ta. That is, the control unit 59 determines whether the temperature inside the reforming catalyst 53 is equal to or higher than the activation temperature Ta. In this embodiment, the activation temperature Ta is 350°C as described above.

[0055] If the control unit 59 determines in S101 that the first temperature T1 is not equal to or higher than the activation temperature Ta (i.e., is lower than the activation temperature Ta), the process proceeds to S103. Then, the control unit 59 starts the light source device 55 in S103. When the control unit 59 starts the light source device 55, the light source device 55 starts emitting the light flux R to the reforming catalyst 53. In other words, the light source device 55 starts heating the reforming catalyst 53. When S103 ends, the process returns to S101.

[0056] On the other hand, if the control unit 59 determines in S101 that the first temperature T1 is equal to or higher than the activation temperature Ta, the process proceeds to S102. Then, if the light source device 55 has been activated, the control unit 59 stops the light source device 55 in S102. When the control unit 59 stops the light source device 55, the light source device 55 stops emitting the light flux R to the reforming catalyst 53. In other words, the light source device 55 stops heating the reforming catalyst 53.

[0057] Subsequently, in S104, the control unit 59 determines whether the internal combustion engine 1 is operating. If the control unit 59 determines in S104 that the internal combustion engine 1 is not operating, the process returns to S101.

[0058] On the other hand, if the control unit 59 determines in S104 that the internal combustion engine 1 is operating, the process proceeds to S105 shown in Fig. 6. Then, the control unit 59 starts the heat exchanger 56 in S105. When the control unit 59 starts the heat exchanger 56, the heat exchanger 56 starts circulating the refrigerant as described above. That is, the heat exchanger 56 starts cooling the gas that has passed through the reforming catalyst 53.

[0059] Subsequently, in S106, the control unit 59 activates the fuel injector 52. When the control unit 59 activates the fuel injector 52, the fuel injector 52 starts injecting fuel into the branch passage 312.

[0060] Next, in S107, the control unit 59 determines whether the second temperature T2 acquired from the second temperature sensor 57B is equal to or lower than the target temperature Tb. That is, the control unit 59 determines whether the gas immediately after passing through the heat exchanger 56 has been cooled to at least the target temperature Tb. The target temperature Tb in this embodiment is 120°C, as described above.

[0061] If the control unit 59 determines in S107 that the second temperature T2 is not equal to or lower than the target temperature Tb (that is, exceeds the target temperature Tb), the process proceeds to S112, which will be described later.

[0062] On the other hand, if the control unit 59 determines in S107 that the second temperature T2 is equal to or lower than the target temperature Tb, the process proceeds to S108. Then, in S108, the control unit 59 determines, based on the gas analysis results acquired from the gas analyzer 58, whether the gas that has passed through the reforming catalyst 53 (in this embodiment, the gas immediately after passing through the reforming catalyst 53 and then the heat exchanger 56) satisfies the post-reforming requirements. The post-reforming requirements are requirements for determining whether the mixed gas has been reformed by the reforming catalyst 53. Therefore, in S108, the control unit 59 can also be said to determine whether the mixed gas has been reformed by the reforming catalyst 53. In other words, in S108, the control unit 59 determines whether the reformed gas has been produced. The post-reforming requirements include at least a requirement that the gas contain hydrogen.

[0063] In S108, if the control unit 59 determines that the gas that has passed through the reforming catalyst 53 satisfies the post-reformed requirements, the process returns to S107.

[0064] On the other hand, if the control unit 59 determines in S108 that the gas that has passed through the reforming catalyst 53 does not satisfy the post-reforming requirements, the process proceeds to S109. Then, in S109, the control unit 59 determines whether the first temperature T1 acquired from the first temperature sensor 57A is equal to or higher than the activation temperature Ta. For example, if the reaction by which the reforming catalyst 53 reforms the mixed gas is an endothermic reaction, it is conceivable that the first temperature T1 will gradually decrease and fall below the activation temperature Ta. In this case, it is conceivable that the reaction by which the reforming catalyst 53 reforms the mixed gas will no longer progress, and the gas that has passed through the reforming catalyst 53 will no longer satisfy the post-reforming requirements. For this reason, if it is determined in S108 that the gas that has passed through the reforming catalyst 53 does not satisfy the post-reforming requirements, the first temperature T1 is checked in S109.

[0065] If the control unit 59 determines in S109 that the first temperature T1 is not equal to or higher than the activation temperature Ta (i.e., is lower than the activation temperature Ta), the process proceeds to S111. Then, in S111, the control unit 59 starts up the light source device 55. When S111 ends, the process returns to S107.

[0066] On the other hand, if the control unit 59 determines in S109 that the first temperature T1 is equal to or higher than the activation temperature Ta, the process proceeds to S110. Then, if the light source device 55 has been activated, the control unit 59 stops the light source device 55 in S110. When S110 ends, the process returns to S107.

[0067] As described above, if the control unit 59 determines in S107 that the second temperature T2 is not equal to or lower than the target temperature Tb, the process proceeds to S112. In S112, the control unit 59 turns on the malfunction lamp. Then, in the following S113, the control unit 59 shuts down the fuel reforming system 50. Shutting down the fuel reforming system 50 includes shutting down the fuel injector 52, the light source device 55, and the heat exchanger 56. If it is determined in S107 that the second temperature T2 is not equal to the target temperature Tb even though the heat exchanger 56 was started in S105, it is possible that the heat exchanger 56 is not operating normally. For this reason, in S112 and S113, the malfunction lamp is turned on and the fuel reforming system 50 is shut down.

[0068] Although not shown in the figure, if the power supply to the vehicle is turned off while steps S101 to S111 are being executed, the process also proceeds to step S113, where the fuel reforming system 50 is stopped.

[0069] When S113 is completed, the fuel reforming process is completed.

[0070] [3.Effects] According to the embodiment described above in detail, the following effects can be obtained.

[0071] (3a) The fuel reforming system 50 includes a reforming flow path member 51, a fuel injection device 52, a reforming catalyst 53, and a light source device 55. The light source device 55 is configured to emit a light flux R including infrared rays to the reforming catalyst 53.

[0072] With this configuration, the reforming catalyst 53 can be heated by the infrared rays contained in the light flux R. This is true regardless of the presence or temperature of exhaust gas emitted from the internal combustion engine 1. Therefore, for example, the reforming catalyst 53 can be heated even before the internal combustion engine 1 starts operating or immediately after the internal combustion engine 1 starts operating. In other words, it is possible to easily reform the mixed gas regardless of the operating state of the internal combustion engine 1. As a result, the reforming catalyst 53 can be warmed up quickly.

[0073] Furthermore, heating the reforming catalyst 53 with the infrared rays contained in the light flux R is less affected by the outside temperature. Therefore, for example, even in an environment where the outside temperature is low, it is possible to heat the reforming catalyst 53. As a result, it becomes easier to reform the mixed gas.

[0074] (3b) The reforming catalyst 53 has a plurality of cells 531. The light source device 55 is configured to emit the light flux R so that at least some of the plurality of light rays L constituting the light flux R intersect with the inner surfaces 531b of the plurality of cells 531.

[0075] According to this configuration, it is possible to make it easier for the infrared rays contained in the light beam R to be absorbed by the inner surfaces 531b of the plurality of cells 531. This makes it easier to heat the inner surfaces 531b of the plurality of cells 531. As a result, it is possible to make it easier to reform the mixed gas.

[0076] (3c) The light source device 55 is configured to emit a luminous flux R in which multiple light rays L converge. In this case, the intensity of the luminous flux R is particularly high in the convergence region F. Therefore, the light source device 55 is disposed so that the convergence region F does not overlap with the upstream surfaces 531a of the multiple cells 531. In other words, the light source device 55 is disposed so that the convergence region F does not overlap with the outer surface of the multiple cells 531 that is on the light source device 55 side in the flow direction of the branch flow channel 312. With this configuration, the convergence region F, where the intensity of the luminous flux R is particularly high, does not overlap with the upstream surfaces 531a of the multiple cells 531, so that the reforming catalyst 53 can be prevented from being overheated. Therefore, deterioration of the reforming catalyst 53 can be suppressed.

[0077] (3d) The light source device 55 is configured to emit the light flux R from the upstream side relative to the reforming catalyst 53. With this configuration, compared to when the light source device 55 is configured to emit the light flux R from the downstream side relative to the reforming catalyst 53, it is possible to make it easier to heat the upstream portion of the reforming catalyst 53 and make it harder to heat the downstream portion of the reforming catalyst 53. Therefore, while maintaining the effect of making it easier to reform the mixed gas by the reforming catalyst 53, it is possible to prevent the temperature of the gas that has passed through the reforming catalyst 53 from becoming too high. As a result, it is possible to make it easier to improve the combustion efficiency of the internal combustion engine 1. This is because the lower the temperature of gas, the higher the density becomes, and the amount of reformed gas containing hydrogen per unit volume increases.

[0078] (3e) In this embodiment, the light source device 55 is a halogen lamp heater. The light flux R emitted from the halogen lamp heater includes near-infrared rays among other infrared rays. When near-infrared rays are absorbed by a substance, they are particularly effective in heating the substance. Therefore, with the above-described configuration, the reforming catalyst 53 can be heated even more easily. Consequently, the mixed gas can be reformed even more easily.

[0079] (3f) In this embodiment, the plurality of cells 531 are made of alumina. With this configuration, the plurality of cells 531 have high thermal conductivity, which makes it possible to heat the reforming catalyst 53 even more easily. Therefore, for example, the reforming catalyst 53 can be heated even more easily without applying an electromagnetic wave absorber or the like to the surfaces of the plurality of cells 531. Consequently, it becomes possible to reform the mixed gas even more easily.

[0080] 4. Other Embodiments Although the embodiments of the present disclosure have been described above, it goes without saying that the present disclosure is not limited to the above-described embodiments and can take on various forms.

[0081] (4a) In the above embodiment, the light source device 55 is disposed so that the convergence region F does not overlap with the upstream surfaces 531a of the multiple cells 531. Specifically, the light source device 55 is disposed so that the convergence region F is located upstream of the upstream surfaces 531a.

[0082] However, the light source device 55 may be disposed, for example, such that the convergence region F is located downstream of the upstream surface 531a. In other words, the light source device 55 may be configured, for example, to emit the light flux R so that the multiple light rays L reach the reforming catalyst 53 before they finish converging. In this case as well, at least some of the multiple light rays L constituting the light flux R intersect with the inner surfaces 531b of the multiple cells 531 in the reforming catalyst 53. Therefore, an effect similar to that of (3b) above can be obtained.

[0083] (4b) In the above embodiment, the light source device 55 is disposed so that the emission direction D of the light flux R intersects with the central axis X of the reforming catalyst 53. However, as shown in FIG. 8, the light source device 55 may be disposed, for example, so that the emission direction D of the light flux R is parallel to the central axis X of the reforming catalyst 53. In other words, the light source device 55 may be disposed, for example, so that the emission direction D of the light flux R is parallel to the inner surfaces 531b of the multiple cells 531. Even in this case, the light source device 55 is configured to emit a light flux R in which multiple light rays L are converged, and therefore at least some of the multiple light rays L constituting the light flux R intersect with the inner surfaces 531b of the multiple cells 531. Therefore, an effect similar to that of (3b) above can be obtained.

[0084] (4c) In the above embodiment, the light source device 55 is disposed upstream of the reforming catalyst 53. That is, the light source device 55 is configured to emit the light flux R from the upstream side relative to the reforming catalyst 53. However, the light source device 55 may also be disposed downstream of the reforming catalyst 53, for example. That is, the light source device 55 may be configured to emit the light flux R from the downstream side relative to the reforming catalyst 53, for example. In this case, it is preferable that the light source device 55 is disposed so that the convergence region F does not overlap with the downstream surfaces of the multiple cells 531 in the reforming catalyst 53. This is because an effect similar to that described in (3c) above can be obtained. Note that the downstream surfaces of the multiple cells 531 refer to the downstream surfaces of the outer surfaces of the multiple cells 531. When the light source device 55 is disposed downstream of the reforming catalyst 53, the downstream surfaces of the multiple cells 531 correspond to the surfaces of the outer surfaces of the multiple cells 531 that are on the light source device 55 side in the flow direction of the branch flow channel 312.

[0085] (4d) In the above embodiment, the light source device 55 is configured to emit a light beam R in which multiple light rays L converge. However, when the light beam is emitted in one emission direction D as a whole, the directions of the multiple light rays L included in the light beam are not particularly limited.

[0086] For example, as shown in FIG. 9, the light source device 55A may be configured to emit a light flux Ra in which a plurality of light rays L are parallel to one another. That is, the light source device 55A may be a so-called parallel light type. The position of such a light source device 55A relative to the reforming catalyst 53 is not particularly limited. For example, the light source device 55A may be disposed so that the emission direction D of the light flux Ra intersects with the central axis X of the reforming catalyst 53, as with the light source device 55 of the above embodiment. In other words, the light source device 55A may be disposed so that the emission direction D of the light flux Ra intersects with the inner surfaces 531b of the plurality of cells 531. In this case, at least some of the plurality of light rays L constituting the light flux Ra intersect with the inner surfaces 531b of the plurality of cells 531 in the reforming catalyst 53. Therefore, an effect similar to that of (3b) above can be obtained.

[0087] 10, the light source device 55B may be configured to emit a light flux Rb in which a plurality of light rays L are diffused. That is, the light source device 55B may be a so-called diffusion type. With this configuration, similar to the light source device 55 of the above embodiment, at least some of the plurality of light rays L constituting the light flux Rb intersect with the inner surfaces 531b of the plurality of cells 531 in the reforming catalyst 53, regardless of the position of the light source device 55B relative to the reforming catalyst 53. Therefore, it is possible to obtain the same effect as in (3b) above.

[0088] (4e) In the above embodiment, the fuel reforming system 50 has one light source device 55. However, for example, as shown in FIG. 11, the fuel reforming system 50A may have two light source devices 55. Also, for example, the fuel reforming system may have three or more light source devices. In other words, the number of light source devices provided in the fuel reforming system is not particularly limited.

[0089] (4f) In the above embodiment, the light source device 55 is a halogen lamp heater having a halogen lamp as a light source. However, the light source device may have any light source that emits multiple light rays including infrared rays. For example, the light source device may be a xenon lamp heater having a xenon lamp as a light source.

[0090] (4g) In the fuel reforming system 50 of the above embodiment, the fuel injector 52 is fixed to the wall of the reforming flow path member 51 at a position facing the reforming catalyst 53 from the upstream side. However, the fuel injector 52 does not necessarily have to be disposed at a position facing the reforming catalyst 53. For example, as shown in FIG. 12 , the fuel injector 52 may be fixed to a portion of the wall of the reforming flow path member 51 that surrounds the reforming catalyst 53 when viewed along the central axis X of the reforming catalyst 53.

[0091] (4h) As shown in FIG. 13, the fuel reforming system 50B may further include, for example, an agitator 90. The agitator 90 is configured to agitate the mixed gas, for example, between the fuel injector 52 and the light source device 55 in the branch flow path 312. As shown in FIG. 14, for example, the agitator 90 may have a cylindrical portion 91 and two types of blades 92a, 92b. The cylindrical portion 91 is a cylindrical portion fixed to the inner surface of the reforming flow path member 51. The two types of blades 92a, 92b are portions that extend from the downstream end of the cylindrical portion 91 toward the downstream side and toward the central axis of the cylindrical portion 91. With this configuration, it is possible to more uniformly disperse the fuel in the mixed gas.

[0092] (4i) The function of one component in the above embodiments may be distributed among multiple components, or the functions of multiple components may be integrated into one component. Also, part of the configuration of the above embodiments may be omitted. Furthermore, at least part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments.

[0093] (4j) In addition to the fuel reforming system 50 described above, the present disclosure can be realized in various forms, such as a program for causing a computer to function as the fuel reforming system 50, a medium on which this program is recorded, and a fuel reforming method.

[0094] [Technical idea disclosed in this specification] [Item 1] A fuel reforming system provided in an intake system of an internal combustion engine, a flow path member that forms an intake flow path to the internal combustion engine; a fuel injector configured to inject fuel into the intake passage; a reforming catalyst configured to reform the injected gas containing the fuel, located downstream of the fuel injection device in the intake passage; a light source device configured to emit a light beam including infrared rays toward the reforming catalyst; A fuel reforming system comprising:

[0095] [Item 2] Item 1, the fuel reforming system according to item 1, the reforming catalyst has a plurality of cells, which are a plurality of cylindrical portions extending in the flow direction of the intake passage, A fuel reforming system, wherein the light source device is configured to emit the light beam so that at least some of the plurality of light rays constituting the light beam intersect with inner surfaces of the plurality of cells.

[0096] [Item 3] Item 2: The fuel reforming system according to item 2, The light source device is The light source is configured to emit the light beam in which the plurality of light rays converge, A fuel reforming system in which the region where the multiple light rays in the light flux converge is arranged so as not to overlap with the surface of the outer surfaces of the multiple cells that faces the light source device in the flow direction of the intake air flow path.

[0097] [Item 4] Item 2: The fuel reforming system according to item 2, The light source device is The plurality of light beams are configured to emit the light beams parallel to each other, A fuel reforming system, wherein the plurality of light beams are arranged to intersect with the inner surfaces of the plurality of cells.

[0098] [Item 5] A fuel reforming system according to any one of items 1 to 4, The light source device is configured to emit the light flux from an upstream side of the reforming catalyst.

[0099] [Item 6] A fuel reforming system according to any one of items 1 to 5, The fuel reforming system, wherein the light source device is a halogen lamp heater. [Explanation of symbols]

[0100] 1...internal combustion engine, 2...intake system, 30...intake flow path member, 31...intake flow path, 311...main flow path, 312...branch flow path, 50...fuel reforming system, 51...reforming flow path member, 52...fuel injection device, 53...reforming catalyst, 531...cell, 531a...upstream surface, 531b...inner surface, 55...light source device, 56...heat exchanger, 59...control unit, 6...exhaust system, D...emission direction, F...focusing area, L...light ray, R...light flux, X...central axis

Claims

1. A fuel reforming system provided in an intake system of an internal combustion engine, a flow path member that forms an intake flow path to the internal combustion engine; a fuel injector configured to inject fuel into the intake passage; a reforming catalyst configured to reform the injected gas containing the fuel, located downstream of the fuel injection device in the intake passage; a light source device configured to emit a light beam including infrared rays toward the reforming catalyst; A fuel reforming system comprising:

2. 10. The fuel reforming system of claim 1, the reforming catalyst has a plurality of cells, which are a plurality of cylindrical portions extending in the flow direction of the intake passage, A fuel reforming system, wherein the light source device is configured to emit the light beam so that at least some of the plurality of light rays constituting the light beam intersect with inner surfaces of the plurality of cells.

3. 3. The fuel reforming system of claim 2, The light source device is The light source is configured to emit the light beam in which the plurality of light rays converge, A fuel reforming system in which the region where the multiple light rays in the light flux converge is arranged so as not to overlap with the surface of the outer surfaces of the multiple cells that faces the light source device in the flow direction of the intake air flow path.

4. 3. The fuel reforming system of claim 2, The light source device is The plurality of light beams are configured to emit the light beams parallel to each other, a fuel reforming system, wherein the cells are arranged so that the emission direction of the light beam intersects with the inner surfaces of the cells;

5. 3. The fuel reforming system according to claim 1 or 2, The light source device is configured to emit the light flux from an upstream side of the reforming catalyst.

6. 3. The fuel reforming system according to claim 1 or 2, The fuel reforming system, wherein the light source device is a halogen lamp heater.

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