JP2005299500A - Internal combustion engine using hydrogen - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase the production quantity of hydrogen by improving reaction efficiency when inducing a dehydrogenation reaction using energy of exhaust gas. <P>SOLUTION: An internal combustion engine using hydrogen is provided with a hydrogenated gasoline injector 24 for supplying catalysts 72 with organic hydride containing fuel and a hydrogen supply injector 18 for supplying an internal combustion engine 10 with hydrogen taken out from the organic hydride containing fuel by the dehydrogenation reaction on the catalysts 72. The internal combustion engine 10 has a plurality of cylinders and the plurality of catalysts 72 are respectively built in a plurality of exhaust passages 14a-14d provided for every cylinder or for every cylinder group in a state that they are shut off from contact with exhaust gas flowing through the exhaust passages 14a-14d. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a hydrogen-utilizing internal combustion engine.

  Conventionally, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2003-343360, an internal combustion engine system having a hydrogen generation function is known. Specifically, this system uses a hydrogenated fuel containing an organic hydride such as decalin as a raw material to generate a hydrogen rich gas and a dehydrogenated product such as naphthalene, and the generated hydrogen rich gas as a fuel. It has a working hydrogen engine.

  The system disclosed in the above publication separates hydrogenated fuel into a hydrogen-rich gas and a dehydrogenated product using heat generated during the operation of the hydrogen engine. More specifically, hydrogenated fuel is injected onto the catalyst, and a dehydrogenation reaction is caused on the catalyst to take out hydrogen. At this time, in order to efficiently extract hydrogen, the catalyst is heated using the waste heat of the engine.

JP 2003-343360 A JP 2002-255503 A JP-A-6-2615

  As a method of heating the catalyst using the waste heat of the engine, it is conceivable to heat the catalyst using the energy of the exhaust gas of the engine. However, when hydrogen is extracted by heating the catalyst using the energy of the exhaust gas, if the exhaust heat cannot be used effectively, the amount of hydrogen extracted with respect to the amount of hydrogen required by the engine may be insufficient.

  Further, since the dehydrogenation reaction is an endothermic reaction, the temperature of the catalyst is lowered due to the endotherm accompanying the reaction, and the reactivity may be lowered.

  The present invention has been made to solve the above-described problems. In the case where the dehydrogenation reaction is caused by using the energy of the exhaust gas, the reaction efficiency is improved and the amount of hydrogen generated is increased. Objective.

  In order to achieve the above object, the first invention provides a fuel supply means for supplying an organic hydride-containing fuel to a catalyst, and an internal combustion engine for removing hydrogen extracted from the organic hydride-containing fuel by a dehydrogenation reaction on the catalyst. The internal combustion engine has a plurality of cylinders, and a plurality of exhaust passages provided for each cylinder or each cylinder group, in contact with the exhaust gas flowing through the exhaust passages Each of the plurality of catalysts is incorporated in a state where the catalyst is cut off.

  According to a second aspect of the present invention, in the first aspect, a hydrogen amount acquisition unit that acquires a hydrogen amount required by the internal combustion engine; and, if the hydrogen amount is equal to or less than a predetermined threshold value, The fuel supply stopping means for stopping the supply of the organic hydride-containing fuel to a part of the catalyst, and the exhaust gas flowing through the exhaust passage incorporating the catalyst for which the supply of the organic hydride-containing fuel is stopped, Exhaust gas supply control means for supplying to an exhaust passage containing a catalyst whose supply is not stopped.

  When the temperature of the said catalyst to which the organic hydride containing fuel is supplied in the 2nd invention is further provided with the temperature detection means which detects the temperature of the said catalyst, and becomes below a predetermined threshold value Is characterized in that the supply of the organic hydride-containing fuel to the catalyst is stopped, and the organic hydride-containing fuel is supplied to the catalyst that has been stopped.

  According to a fourth invention, in the second invention, when a predetermined time has elapsed, the supply of the organic hydride-containing fuel to the catalyst to which the organic hydride-containing fuel is supplied is stopped, and the supply is stopped An organic hydride-containing fuel is supplied to the catalyst.

  According to the first invention, since a plurality of catalysts are built in each of the plurality of exhaust passages, a dehydrogenation reaction can be caused in each catalyst. Accordingly, the amount of hydrogen produced can be increased.

  According to the second aspect of the present invention, the exhaust gas flowing through the exhaust passage containing the catalyst in which the supply of the organic hydride-containing fuel is stopped is transferred to the exhaust passage containing the catalyst in which the supply of the organic hydride-containing fuel is not stopped. Since the fuel is supplied, the temperature of the catalyst in which the dehydration reaction is generated by supplying the organic hydride-containing fuel can be increased. As a result, the efficiency of the dehydrogenation reaction can be improved, and the amount of hydrogen produced can be increased by increasing the conversion ratio to hydrogen.

  According to the third invention, when the temperature of the catalyst to which the organic hydride-containing fuel is supplied becomes equal to or lower than a predetermined threshold value, the supply of the organic hydride-containing fuel to the catalyst is stopped and the supply is stopped. Since the organic hydride-containing fuel is supplied to the stopped catalyst, it is possible to prevent the organic hydride-containing fuel from being supplied to the catalyst whose temperature has decreased due to the endothermic action of the dehydrogenation reaction. Therefore, the efficiency of the dehydrogenation reaction can be increased.

  According to the fourth invention, when a predetermined time has elapsed, the supply of the organic hydride-containing fuel to the catalyst to which the organic hydride-containing fuel is supplied is stopped, and the supply of the catalyst that has been stopped contains the organic hydride Since the fuel is supplied, it is possible to suppress the supply of the organic hydride-containing fuel to the catalyst whose temperature has decreased due to the endothermic action of the dehydrogenation reaction. Therefore, the efficiency of the dehydrogenation reaction can be increased.

  An embodiment of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the element which is common in each figure, and the overlapping description is abbreviate | omitted. The present invention is not limited to the following embodiments.

  FIG. 1 is a diagram for explaining a configuration of an internal combustion engine system according to each embodiment of the present invention. This system includes an internal combustion engine 10. An intake pipe 12 and an exhaust pipe 14 communicate with the internal combustion engine 10.

  A throttle valve 16 for controlling the intake air amount is incorporated in the intake pipe 12. A hydrogen supply injector 18 is disposed downstream of the throttle valve 16. A gasoline supply injector 20 is disposed at the intake port of the internal combustion engine 10.

  A hydrogen rich gas is supplied to the hydrogen supply injector 18 at a predetermined pressure, as will be described later. The hydrogen supply injector 18 opens a valve in response to a drive signal supplied from the outside, and can inject an amount of hydrogen rich gas into the intake pipe 12 according to the valve opening time. In the system shown in FIG. 1, the hydrogen supply injector 18 is arranged in the intake pipe 12, but the arrangement is not limited to this. That is, the hydrogen supply injector 18 may be incorporated in the main body of the internal combustion engine 10 so that hydrogen can be injected into the cylinder.

  As will be described later, gasoline is supplied to the gasoline supply injector 20 at a predetermined pressure. The gasoline supply injector 20 opens a valve in response to a drive signal supplied from the outside, so that an amount of gasoline corresponding to the valve opening time can be injected into the intake port.

  A dehydrogenation reactor 22 is attached to the exhaust pipe 14. In addition, a hydrogenated gasoline injector 24 is assembled on the upper part of the dehydrogenation reactor 22.

  As will be described later, the hydrogenated gasoline injector 24 is supplied with hydrogenated gasoline at a predetermined pressure. The hydrogenated gasoline injector 24 is opened in response to a drive signal supplied from the outside, so that it corresponds to the valve opening time. An amount of hydrogenated gasoline can be fed into the dehydrogenation reactor 22. Here, the amount of hydrogen required by the internal combustion engine 10 varies depending on the operating state of the internal combustion engine 10. The ECU 80 stores a map that defines the relationship between the amount of hydrogen required by the internal combustion engine 10 and the operating state (engine speed, load (throttle opening)), and obtains the required amount of hydrogen from this map. The valve opening / closing state of the hydrogenated gasoline injector 24 is controlled. Further, the dehydrogenation reactor 22 uses the exhaust heat radiated from the exhaust pipe 14 to separate the hydrogenated gasoline supplied as described above into a hydrogen rich gas and a dehydrogenated gasoline and flow them out. have.

An exhaust temperature sensor 25 is incorporated in the exhaust pipe 14 upstream of the dehydrogenation reactor 22. Further, an O ₂ sensor 26 and a NOx sensor 28 are incorporated in the exhaust pipe 14 downstream of the dehydrogenation reactor 22. The O ₂ sensor 26 is a sensor that emits an output corresponding to the exhaust air / fuel ratio based on the presence or absence of oxygen in the exhaust gas. The NOx sensor 28 is a sensor that emits an output corresponding to the NOx concentration in the exhaust gas. A catalyst 30 for purifying exhaust gas is disposed downstream of these sensors 26 and 28.

  The system of this embodiment includes a hydrogenated gasoline tank 32. In the hydrogenated gasoline tank 32, hydrogenated gasoline containing a large amount of organic hydride as compared with general gasoline is stored. Here, the “organic hydride” is a hydrocarbon (HC) component that causes a dehydrogenation reaction at a temperature of about 300 ° C., and specifically, decalin and cyclohexane correspond to this.

Ordinary gasoline (LFT-1C) contains about 40% of toluene. When toluene is hydrogenated, methylcyclohexane (C ₇ H ₁₄ ), which is an organic hydride, can be produced. That is, hydrogenation gasoline containing about 40% of methylcyclohexane can be produced by hydrogenating toluene contained in ordinary gasoline as a raw material. In the present embodiment, for the sake of convenience, the hydrogenated gasoline tank 32 is supplied with hydrogenated gasoline having such a composition.

  A hydrogenated gasoline supply pipe 34 communicates with the hydrogenated gasoline tank 32. The hydrogenated gasoline supply pipe 34 includes a pump 36 in the middle thereof and communicates with the hydrogenated gasoline injector 24 at the end thereof. Hydrogenated gasoline in the hydrogenated gasoline tank 32 is pumped up by a pump 36 during operation of the internal combustion engine, and is supplied to the hydrogenated gasoline injector 24 at a predetermined pressure.

  The hydrogenated gasoline injector 24 is assembled to the upper part of the dehydrogenation reactor 22 as described above. The dehydrogenation reactor 22 is an apparatus for processing hydrogenated gasoline using exhaust heat. For this reason, during operation of the internal combustion engine, the interior of the dehydrogenation reactor 22 rises to a temperature exceeding 300 ° C.

  The hydrogenated gasoline injector 24 is assembled so that the main portion protrudes into the space above the dehydrogenation reactor 22 in order to avoid direct exposure to the internal temperature. For this reason, according to the system of this embodiment, the temperature of the hydrogenated gasoline injector 24 does not become unduly high.

  In the system shown in FIG. 1, the hydrogenated gasoline injector 24 is cooled by air, but the cooling method is not limited to this. For example, a cooling water passage for guiding the cooling water of the internal combustion engine 10 to the periphery of the hydrogenated gasoline injector 24 may be provided to cool the hydrogenated gasoline injector 24 with water.

  A reaction chamber is formed inside the dehydrogenation reactor 22. The fuel injected from the hydrogenated gasoline injector 24 is separated into hydrogen-rich gas and dehydrogenated gasoline inside the reaction chamber, and is led to a pipe line 38 connected to the dehydrogenation reactor 22. A separation device 40 communicates with the dehydrogenation reactor 22 via a pipe line 38.

As described above, the hydrogenated gasoline used in the present embodiment is obtained by organically hydrating toluene contained in normal gasoline. Therefore, if the hydrogenated gasoline is subjected to a dehydrogenation treatment, hydrogen-rich gas and ordinary gasoline are generated as a result. Specifically, methylcyclohexane C ₇ H ₁₄ which is an organic hydride is separated into hydrogen H ₂ and toluene C ₇ H ₈ as follows by a dehydrogenation reaction.
C ₇ H ₁₄ → C ₇ H ₈ + 3H ₂ (1)
The dehydrogenation reaction represented by the formula (1) is an endothermic reaction.

  For this reason, specifically, a mixture of hydrogen-rich gas and ordinary gasoline is supplied from the dehydrogenation reactor 22 to the separation device 40.

  The separation device 40 has a function of cooling the high-temperature hydrogen-rich gas and dehydrogenated gasoline (ordinary gasoline) supplied from the dehydrogenation reactor 22 and separating them. Similar to the internal combustion engine 10, the separation device 40 is water-cooled by circulating cooling water. For this reason, the separator 40 can cool the hydrogen rich gas and the dehydrogenated gasoline efficiently.

  A liquid storage space for storing dehydrogenated gasoline liquefied by being cooled is provided at the bottom of the separation device 40. Further, a gas storage space for storing the hydrogen-rich gas remaining as a gas is secured above the storage space. The separator 40 is connected with a gasoline pipe line 42 so as to communicate with the liquid storage space, and with a hydrogen pipe line 44 so as to communicate with the gas storage space.

  The gasoline pipeline 42 communicates with the gasoline buffer tank 48. Although FIG. 1 shows a configuration in which the hydrogenated gasoline tank 32 and the gasoline buffer tank 48 are arranged at positions separated from each other, the configuration is not limited to this. That is, they may be housed in a single housing.

  A liquid amount sensor 58 is assembled in the gasoline buffer tank 48. The liquid amount sensor 58 is a sensor that emits an output corresponding to the amount of dehydrogenated gasoline stored therein. In addition, a gasoline supply pipe 60 communicates with the gasoline buffer tank 48. The gasoline supply pipe 60 includes a pump 62 in the middle thereof and communicates with the gasoline supply injector 20 at an end thereof. The dehydrogenated gasoline in the gasoline buffer tank 48 is pumped up by the pump 62 during operation of the internal combustion engine, and is supplied to the gasoline supply injector 20 at a predetermined pressure.

  The hydrogen pipe 44 communicates with the hydrogen buffer tank 64. The hydrogen pipe 44 incorporates a pump 66 for pumping the hydrogen-rich gas in the separator 40 to the hydrogen buffer tank 64 and a relief valve 68 for preventing the discharge side pressure of the pump 66 from becoming excessive. It is. According to the pump 66 and the relief valve 68, the hydrogen rich gas can be fed into the hydrogen buffer tank 64 within a range in which the internal pressure does not become excessive.

  A pressure sensor 70 is assembled in the hydrogen buffer tank 64. The pressure sensor 70 is a sensor that generates an output corresponding to the internal pressure of the hydrogen buffer tank 64. According to the output of the pressure sensor 70, the amount of hydrogen rich gas stored in the hydrogen buffer tank 64 can be estimated.

  A hydrogen supply pipe 71 communicates with the hydrogen buffer tank 64. The hydrogen supply pipe 71 includes a regulator 73 in the middle thereof and communicates with the hydrogen supply injector 18 at an end thereof. According to such a configuration, the hydrogen rich gas is supplied to the hydrogen supply injector 18 by the pressure adjusted by the regulator 73 on the condition that the hydrogen rich gas is stored in the hydrogen buffer tank 64.

The system of this embodiment includes an ECU 80. The ECU 80 has a function of controlling the system of this embodiment. That is, the ECU 80 is supplied with outputs from various sensors such as the O ₂ sensor 26, the NOx sensor 28, the liquid amount sensor 58, and the pressure sensor 70 described above. The ECU 80 is connected to the above-described pumps 36, 62, 66 and actuators such as the injectors 18, 20, 24. The ECU 80 can appropriately drive the various actuators described above by performing predetermined processing based on these sensor outputs.

  Next, based on FIG.2 and FIG.3, the structure of the dehydrogenation reactor 22 is demonstrated in detail. FIG. 2 is a cross-sectional view showing the configuration of the dehydrogenation reactor 22. As shown in FIG. 2, a catalyst 72 for causing a dehydrogenation reaction is provided in a casing 74, and the casing 74 is inserted into the exhaust pipe 14 with its longitudinal direction facing the exhaust gas flow direction. Yes. Both ends of the casing 74 protrude out of the exhaust pipe 14, and the injector 24 is provided at the upper end. A heat insulating material 76 is wound around the outer periphery of the exhaust pipe 14 in the region where the casing 74 is inserted.

  FIG. 3 is a cross-sectional view showing a cross section taken along the alternate long and short dash line I-I ′ of FIG. 2. As shown in FIG. 3, the casing 74 is disposed at the center in the exhaust pipe 14, and in the area where the casing 74 is inserted, the inside of the exhaust pipe 14 has a two-layer structure. Accordingly, the casing 74 is surrounded by the exhaust gas flowing outside in the exhaust pipe 14, and heat supply to the catalyst 72 can be efficiently performed.

  Thereby, the utilization efficiency of exhaust heat can be significantly increased, and the dehydrogenation reaction in the catalyst 72 can be promoted. As described above, since the dehydrogenation reaction is an endothermic reaction, the reaction efficiency decreases when the temperature of the catalyst 72 decreases. However, according to the configuration of the present embodiment, the amount of hydrogen required in the internal combustion engine 10 is small. Even when the amount becomes large, it is possible to minimize the decrease in the internal temperature of the catalyst 72. Thereby, hydrogen can always be generated stably. Moreover, since the heat insulating material 76 is wound around the exhaust pipe 14 in the region where the casing 74 is inserted, it is possible to minimize the exhaust heat from leaking to the outside, and to further improve the efficiency of using the exhaust heat. .

  Further, since the end portion of the casing 74 is protruded to the outside of the exhaust pipe 14, it is possible to supply fuel to the catalyst 72 only by mounting the injector 24 at the end portion. Accordingly, it is not necessary to provide an opening for supplying fuel to the catalyst 72 in the exhaust pipe 14 itself, and the fuel can be supplied to the catalyst 72 with a simple configuration. Therefore, the productivity of the dehydrogenation reactor 22 can be increased. Further, since the dehydrogenation reactor 22 has a two-layer structure, the diameter can be reduced, and the mountability can be improved.

  Next, the relationship between each cylinder of the internal combustion engine 10 and the dehydrogenation reactor 22 will be described with reference to FIG. In this embodiment, as shown in FIG. 4, two dehydrogenation reactors 22a and 22b are provided. The dehydrogenation reactors 22 a and 22 b are connected by a pipe 78, and the hydrogenated gasoline supplied from the hydrogenated gasoline supply pipe 34 is provided to the dehydrogenation reactors 22 a and 22 b by the pipe 78. It is distributed to the injector 24.

  As shown in FIG. 4, the internal combustion engine 10 of the present embodiment is composed of four cylinders # 1 to # 4. Each cylinder is connected to exhaust pipes 14a to 14d, and each cylinder and the dehydrogenation reactors 22a and 22b are connected to each other by exhaust pipes 14a to 14d. That is, the # 1 cylinder is connected to the dehydrogenation reactor 22a by the exhaust pipe 14a, and the # 4 cylinder is connected to the dehydrogenation reactor 22a by the exhaust pipe 14d. The # 2 cylinder is connected to the dehydrogenation reactor 22b by the exhaust pipe 14b, and the # 3 cylinder is connected to the dehydrogenation reactor 22b by the exhaust pipe 14c.

  As described above, in this embodiment, by providing two dehydrogenation reactors 22, the dehydrogenation reaction is caused in each of the dehydrogenation reactors 22 a and 22 b to increase the amount of hydrogen generated.

  In order to increase the amount of hydrogen produced in the dehydrogenation reactor 22, it is conceivable to increase the volume of the catalyst 72. However, simply increasing the size of the catalyst 72 may prevent the fuel injected from the injector 24 from reaching the entire area of the catalyst 72, so it is difficult to increase the reaction efficiency. In this embodiment, since the two dehydrogenation reactors 22a and 22b are provided, the dehydrogenation reactors 22a and 22b can be configured relatively small, and the dehydrogenation reactors 22a and 22b of both the catalysts 72 can be formed. The dehydrogenation reaction can be caused almost all over. Therefore, the amount of hydrogen produced can be greatly increased.

  In the case of a four-cylinder internal combustion engine, an explosion stroke is performed every crank angle of 180 ° in the order of # 1- # 3- # 4- # 2, and exhaust gas is discharged from each cylinder in this order. At this time, as shown in FIG. 4, by connecting the dehydrogenation reactor 22a and # 1, # 4 cylinder, and connecting the dehydrogenation reactor 22b and # 2, # 3 cylinder, # 1- # 3- The exhaust gases discharged in the order of # 4- # 2 are alternately sent to the dehydrogenation reactors 22a and 22b. As a result, exhaust gas is sent to the dehydrogenation reactors 22a and 22b at equal intervals of every crank angle of 360 °, and the temperature fluctuation of the catalyst 72 can be minimized. In addition, by alternately sending the exhaust gas discharged in each explosion stroke to the dehydrogenation reactors 22a and 22b, it becomes possible to maintain the temperatures of both dehydrogenation reactors 22a and 22b substantially uniformly. Thereby, hydrogen can be generated stably. Even when the internal combustion engine is an engine other than the four-cylinder engine, it is preferable to send the exhaust gas discharged in each explosion stroke to the plurality of dehydrogenation reactors 22 in a balanced manner.

  As described above, according to the first embodiment, since the exhaust gas discharged from the internal combustion engine 10 is supplied to the two dehydrogenation reactors 22a and 22b, the hydrogen is supplied to both the dehydrogenation reactors 22a and 22b. Can be generated. Thereby, the reaction efficiency in each dehydrogenation reactor 22a, 22b can be raised, and it becomes possible to increase the production amount of hydrogen.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described. FIG. 5 is a schematic diagram showing the configuration of the second embodiment, and shows the relationship between each cylinder of the internal combustion engine 10 and the dehydrogenation reactors 22a and 22b, as in FIG. Also in the second embodiment, two dehydrogenation reactors 22a and 22b are provided as in the first embodiment.

  As shown in FIG. 5, in the second embodiment, the exhaust pipe 14 b and the exhaust pipe 14 c are introduced into the switching valve 82. An exhaust pipe 14e that connects the switching valve 82 and the dehydrogenation reactor 22a and an exhaust pipe 14f that connects the switching valve 82 and the dehydrogenation reactor 22b are provided. The switching valve 82 has a function of sending the exhaust gas sent from the exhaust pipes 14b and 14c to either the exhaust pipe 14e or the exhaust pipe 14f.

  In normal control, the state of the switching valve 82 is set so that the exhaust gas sent from the exhaust pipes 14b and 14c is sent to the dehydrogenation reactor 22b via the exhaust pipe 14f. On the other hand, exhaust gas is sent from the exhaust pipes 14a and 14b to the dehydrogenation reactor 22a. Thereby, like Embodiment 1, hydrogen can be produced | generated by both dehydrogenation reactors 22a and 22b, and the production amount of hydrogen can be increased.

  By the way, as explained in the first embodiment, the amount of hydrogen required by the internal combustion engine varies according to the operating state (rotation speed, load) of the engine and controls the fuel injection amount from the injector 24. The amount of hydrogen produced is controlled. In addition, in Embodiment 2, it is possible to control the amount of hydrogen produced by producing hydrogen in one or both of the dehydrogenation reactors 22a and 22b.

  That is, in the second embodiment, when the amount of hydrogen required by the internal combustion engine 10 is small, the fuel is injected only from the injector 24 of the dehydrogenation reactor 22a, and the fuel is injected from the injector 24 of the dehydrogenation reactor 22b. Stop. Thereby, hydrogen can be generated only by the dehydrogenation reactor 22a, and a necessary amount of hydrogen corresponding to the operating state can be supplied to the internal combustion engine 10.

  When hydrogen is generated only by the dehydrogenation reactor 22a, the exhaust gas sent from the exhaust pipes 14b and 14c is used as the exhaust pipe 14e in order to effectively use the exhaust heat sent to the dehydrogenation reactor 22b that does not generate hydrogen. The state of the switching valve 82 is set so as to be sent to. As a result, the exhaust of the # 1, # 4 cylinder and the exhaust of the # 2, # 3 cylinder are fused, and the exhaust gas of all the cylinders is sent to the dehydrogenation reactor 22a. Therefore, even if endotherm accompanying the generation of hydrogen occurs, the temperature of the catalyst 72 of the dehydrogenation reactor 22a can be maintained at a high temperature, and hydrogen can be stably generated in the dehydrogenation reactor 22a. .

  In this case, for example, it is preferable to send a part of the exhaust gas flowing through the exhaust pipe 14c to the dehydrogenation reactor 22b so that the temperature of the catalyst 72 of the dehydrogenation reactor 22b does not decrease. Thereby, when the production | generation of hydrogen by the dehydrogenation reactor 22b is restarted, it can suppress that reaction efficiency falls.

  FIG. 6 is a flowchart showing a processing procedure in the hydrogen-utilizing internal combustion engine of the second embodiment. First, in step S1, the engine speed and the throttle opening are acquired. In the next step S2, the amount of hydrogen required in the current operating state is calculated from the map based on the engine speed and throttle opening acquired in step S1.

  In the next step S3, it is determined whether or not the necessary hydrogen amount obtained in step S2 is equal to or greater than a predetermined threshold value. Here, the limit hydrogen amount that can be generated in one dehydrogenation reactor 22 is A liter / min, and it is determined whether or not the required hydrogen amount ≧ A.

  If the required hydrogen amount ≧ A in step S3, the amount of hydrogen required in the current operation state is larger than the limit hydrogen amount that can be generated in one dehydrogenation reactor 22, and therefore the process proceeds to step S4. Hydrogenated gasoline is injected from the injectors 24 of the dehydrogenation reactors 22a and 22b, and hydrogen is produced in both dehydrogenation reactors 22a and 22b.

  On the other hand, if the required hydrogen amount <A in step S3, the required hydrogen amount is smaller than the limit hydrogen amount that can be generated by one dehydrogenation reactor 22, and therefore, the process proceeds to step S5, and the switching valve 82 is operated and # The exhaust gas of cylinders # 2 and # 3 is flowed to the dehydrogenation reactor 22a. In the next step S6, fuel injection from the injector 24 of the dehydrogenation reactor 22b is stopped, and hydrogen is generated only by the dehydrogenation reactor 22a.

  As described above, according to the second embodiment, in the operation state where the required hydrogen amount is small, hydrogen is generated only by one of the dehydrogenation reactors 22a, so that an appropriate amount of hydrogen corresponding to the operation state is generated. be able to. Further, by operating the switching valve 82, the exhaust gas supplied to the dehydrogenation reactor 22b that is not producing hydrogen is sent to the dehydrogenation reactor 22a that is producing hydrogen, so that hydrogen is produced. Thus, the temperature of the catalyst 72 of the dehydrogenation reactor 22a can be kept high. Accordingly, it is possible to stably generate hydrogen in the dehydrogenation reactor 22a.

Embodiment 3 FIG.
Next, a third embodiment of the present invention will be described. FIG. 7 is a schematic diagram showing the configuration of the third embodiment, and shows the relationship between each cylinder of the internal combustion engine 10 and the dehydrogenation reactor 22 as in FIG.

  As in the second embodiment, the exhaust pipe 14 b and the exhaust pipe 14 c are introduced into the switching valve 82. An exhaust pipe 14e that connects the switching valve 82 and the dehydrogenation reactor 22a and an exhaust pipe 14f that connects the switching valve 82 and the dehydrogenation reactor 22b are provided. The switching valve 82 has a function of sending the exhaust gas sent from the exhaust pipes 14b and 14c to either the exhaust pipe 14e or the exhaust pipe 14f.

  Further, the exhaust pipe 14 a and the exhaust pipe 14 d are introduced into the switching valve 84. An exhaust pipe 14g for connecting the switching valve 84 to the dehydrogenation reactor 22a and an exhaust pipe 14h for connecting the switching valve 84 and the dehydrogenation reactor 22b are provided. The switching valve 84 has a function of sending the exhaust gas sent from the exhaust pipes 14a and 14d to either the exhaust pipe 14g or the exhaust pipe 14h.

  In the third embodiment, catalyst temperature sensors 88 and 90 are provided to detect the temperatures of the catalysts 72 of both the dehydrogenation reactor 22a and the dehydrogenation reactor 22b.

  In normal control, the state of the switching valve 82 is set so that the exhaust gas sent from the exhaust pipes 14b and 14c is sent to the dehydrogenation reactor 22b via the exhaust pipe 14f. The state of the switching valve 84 is set so that the exhaust gas sent from the exhaust pipes 14a and 14d is sent to the dehydrogenation reactor 22a via the exhaust pipe 14g. Thereby, like Embodiment 1, hydrogen can be produced | generated by both dehydrogenation reactors 22a and 22b, and the production amount of hydrogen can be increased.

  When the amount of hydrogen required by the internal combustion engine 10 is small, hydrogen is generated in one of the dehydrogenation reactors 22a and 22b. When hydrogen is generated only by the dehydrogenation reactor 22a, the fuel is injected only from the injector 24 of the dehydrogenation reactor 22a, and the fuel injection from the injector 24 of the dehydrogenation reactor 22b is stopped. In order to effectively use the exhaust heat sent to the dehydrogenation reactor 22b that is not producing hydrogen, the state of the switching valve 82 is set so that the exhaust gas sent from the exhaust pipes 14b and 14c is sent to the exhaust pipe 14e. Is set. Thereby, hydrogen can be generated only by the dehydrogenation reactor 22a, and a necessary amount of hydrogen corresponding to the operating state can be supplied to the internal combustion engine 10.

  When hydrogen is generated only by the dehydrogenation reactor 22b, the fuel is injected only from the injector 24 of the dehydrogenation reactor 22b, and the fuel injection from the injector 24 of the dehydrogenation reactor 22a is stopped. The state of the switching valve 84 is set so that the exhaust gas flowing through the exhaust pipes 14a and 14d is sent to the exhaust pipe 14h in order to effectively use the exhaust heat sent to the dehydrogenation reactor 22a that is not producing hydrogen. The Thereby, hydrogen can be generated only by the dehydrogenation reactor 22b, and a necessary amount of hydrogen corresponding to the operating state can be supplied to the internal combustion engine 10.

  In this way, when hydrogen is generated in one of the dehydrogenation reactors 22a and 22b, the dehydrogenation reactor that generates hydrogen from the exhaust gas sent to the dehydrogenation reactor 22 that does not generate hydrogen. , The exhaust gas of all cylinders can be sent to the dehydrogenation reactor 22 that is producing hydrogen. Accordingly, the temperature of the catalyst 72 of the dehydrogenation reactor 22 generating hydrogen can be maintained at a high temperature, and hydrogen can be generated stably.

  By the way, when hydrogen is generated only in one of the dehydrogenation reactors 22, the temperature of the catalyst 72 of the dehydrogenation reactor 22 that does not generate hydrogen decreases, and the reaction efficiency decreases when hydrogen generation is resumed. There is a case.

  For this reason, in the third embodiment, when hydrogen is generated only by the dehydrogenation reactor 22a, the temperature of the catalyst 72 of the dehydrogenation reactor 22b is detected by the catalyst temperature sensor 88, and the detected value is more than a predetermined value. If it also decreases, the hydrogen production by the dehydrogenation reactor 22a is stopped and switched to the hydrogen production by the dehydrogenation reactor 22b.

  Similarly, when hydrogen is generated only by the dehydrogenation reactor 22b, the temperature of the catalyst 72 of the dehydrogenation reactor 22a is detected by the catalyst temperature sensor 88, and the detected value is lower than a predetermined value. Stops hydrogen production by the dehydrogenation reactor 22b and switches to hydrogen production by the dehydrogenation reactor 22a.

  As described above, when only one dehydrogenation reactor 22 generates hydrogen, the temperature of the catalyst 72 of the dehydrogenation reactor 22 that does not generate hydrogen is monitored, and the temperature of the catalyst 72 falls below a predetermined value. In this case, by switching the dehydrogenation reactor 22 that generates hydrogen, the temperature of the catalyst 22 of both dehydrogenation reactors 22 can be maintained at a predetermined temperature suitable for the reaction. Therefore, it can suppress that the efficiency of a dehydrogenation reaction falls, and it becomes possible to produce | generate hydrogen stably.

  FIG. 8 is a flowchart showing a processing procedure in the hydrogen-utilizing internal combustion engine of the third embodiment. First, in step S11, the engine speed and the throttle opening are acquired. In the next step S12, the amount of hydrogen required in the current operating state is calculated from the map based on the engine speed and throttle opening acquired in step S11.

  In the next step S13, it is determined whether or not the required hydrogen amount obtained in step S12 is greater than or equal to a predetermined threshold value. Here, the limit hydrogen amount that can be generated in one dehydrogenation reactor 22 is A liter / min, and it is determined whether or not the required hydrogen amount ≧ A.

  If the required hydrogen amount ≧ A in step S13, the amount of hydrogen required in the current operating state is larger than the limit hydrogen amount that can be generated in one dehydrogenation reactor 22, and therefore the process proceeds to step S14. Hydrogenated gasoline is injected from the injectors 24 of the dehydrogenation reactors 22a and 22b, and hydrogen is produced in both dehydrogenation reactors 22a and 22b.

  On the other hand, if the required hydrogen amount <A in step S13, the required hydrogen amount is smaller than the limit hydrogen amount that can be generated by one dehydrogenation reactor 22, the process proceeds to step S15, and the switching valve 84 is operated to perform # While the exhaust gas from the first and # 4 cylinders flows to the dehydrogenation reactor 22a, the switching valve 82 is operated to flow the exhaust gas from the # 2 and # 3 cylinders to the dehydrogenation reactor 22a. In the next step S16, fuel injection from the injector 24 of the dehydrogenation reactor 22b is stopped, and hydrogen is generated only by the dehydrogenation reactor 22a.

  In the next step S17, the temperature of the catalyst 72 of the dehydrogenation reactor 22b that is not producing hydrogen is detected, and it is determined whether or not the catalyst temperature ≦ T ° C. Here, T ° C. is a threshold value that is a lower limit value of the temperature of the catalyst 72. If the catalyst temperature is equal to or lower than T ° C in step S17, the process proceeds to step S18, the switching valve 84 is operated to flow the exhaust gases of # 1 and # 4 cylinders to the dehydrogenation reactor 22b, and the switching valve 82 is operated. The exhaust gas of cylinders # 2 and # 3 is flowed to the dehydrogenation reactor 22b. On the other hand, if the catalyst temperature> T ° C. in step S17, the process waits in step S17, and continues to generate hydrogen only by the dehydrogenation reactor 22a.

  After step S18, the process proceeds to step S19, where fuel is injected from the injector 24 of the dehydrogenation reactor 22b, and fuel injection from the injector 24 of the dehydrogenation reactor 22a is stopped, so that only hydrogen is removed from the dehydrogenation reactor 22b. Is generated.

  As described above, according to the third embodiment, when only one dehydrogenation reactor 22 generates hydrogen, the temperature of the catalyst 72 of the dehydrogenation reactor 22 that does not generate hydrogen is lower than a predetermined value. In the case of the decrease, since the dehydrogenation reactor 22 that generates hydrogen is switched, it is possible to prevent the temperature of the catalyst 22 of the dehydrogenation reactor 22 from decreasing. Therefore, it can suppress that the efficiency of a dehydrogenation reaction falls, and it becomes possible to produce | generate hydrogen stably.

  In the third embodiment, a part of the exhaust gas may be sent to the dehydrogenation reactor 22 that does not generate hydrogen so that the temperature of the catalyst 72 does not decrease.

Embodiment 4 FIG.
Next, a fourth embodiment of the present invention will be described. In the fourth embodiment, the dehydrogenation reactor 22 that generates hydrogen is switched as in the third embodiment. However, the dehydrogenation reaction that generates hydrogen every predetermined time without detecting the temperature of the catalyst 72 is performed. The device 22 is switched.

  FIG. 9 is a flowchart showing a processing procedure in the hydrogen-utilizing internal combustion engine of the fourth embodiment. First, in step S21, the engine speed, throttle opening, and exhaust temperature are acquired. In the next step S22, the amount of hydrogen required in the current operating state is calculated from the map based on the engine speed and throttle opening obtained in step S21.

  In the next step S23, it is determined whether or not the required hydrogen amount obtained in step S22 is greater than or equal to a predetermined threshold value. Here, the limit hydrogen amount that can be generated in one dehydrogenation reactor 22 is A liter / min, and it is determined whether or not the required hydrogen amount ≧ A.

  If the required hydrogen amount ≧ A in step S23, the amount of hydrogen required in the current operating state is larger than the limit hydrogen amount that can be generated in one dehydrogenation reactor 22, and therefore the process proceeds to step S14. Hydrogenated gasoline is injected from the injectors 24 of the dehydrogenation reactors 22a and 22b, and hydrogen is produced in both dehydrogenation reactors 22a and 22b.

  On the other hand, if the required hydrogen amount <A in step S23, the required hydrogen amount is smaller than the limit hydrogen amount that can be generated by one dehydrogenation reactor 22, the process proceeds to step S25, and the switching valve 84 is operated and # While the exhaust gas from the first and # 4 cylinders flows to the dehydrogenation reactor 22a, the switching valve 82 is operated to flow the exhaust gas from the # 2 and # 3 cylinders to the dehydrogenation reactor 22a. In the next step S26, the fuel injection from the injector 24 of the dehydrogenation reactor 22b is stopped, and hydrogen is generated only by the dehydrogenation reactor 22a.

  In the next step S27, it is determined whether or not a predetermined time has elapsed. Here, the predetermined time is a threshold value that varies according to the exhaust gas temperature, and is calculated from the map. The temperature of the catalyst 72 varies depending on the operating conditions of the internal combustion engine 10, and the lower the exhaust temperature, the lower the temperature of the catalyst 72. Therefore, the predetermined time in step S27 is set shorter as the exhaust temperature is lower.

  When the predetermined time has elapsed in step S27, the process proceeds to step S28, the switching valve 84 is operated to flow the exhaust gas of # 1 and # 4 cylinders to the dehydrogenation reactor 22b, and the switching valve 82 is operated to ## The exhaust gas of cylinders # 2 and # 3 is flowed to the dehydrogenation reactor 22b. On the other hand, if the predetermined time has not elapsed in step S27, the process waits in step S27 and continues to generate hydrogen only by the dehydrogenation reactor 22a.

  After the next step S28, the process proceeds to step S29, the fuel injection from the injector 24 of the dehydrogenation reactor 22a is stopped, and hydrogen is generated only by the dehydrogenation reactor 22b.

  According to the process of FIG. 9, the dehydrogenation reactor that generates hydrogen before the temperature of the catalyst 72 on the side that does not generate hydrogen decreases by changing the predetermined time in step S27 according to the exhaust gas temperature. 22 can be switched.

  As described above, according to the fourth embodiment, when only one dehydrogenation reactor 22 generates hydrogen, the dehydrogenation reactor 22 that generates hydrogen is switched at a predetermined time interval. It can suppress that the temperature of the catalyst 72 of the elementary reactor 22 falls. Therefore, it can suppress that the efficiency of a dehydrogenation reaction falls, and it becomes possible to produce | generate hydrogen stably.

  In each of the above-described embodiments, the amount of hydrogen generated is increased by providing two dehydrogenation reactors 22a and 22b, but more dehydrogenation reactors 22 may be provided.

  Further, in each of the above-described embodiments, a hydrogen fuel gasoline is supplied as fuel, hydrogen desorbed from the hydrogenated gasoline by the dehydrogenation process, and a single fuel system that supplies the dehydrogenated gasoline to the internal combustion engine 10. Although an example in which the present invention is applied has been shown, two types of fuel, methylcyclohexane and normal gasoline, are supplied, hydrogen desorbed from methylcyclohexane, and dual fuel for supplying normal gasoline to the internal combustion engine 10 are shown. Of course, it can be applied to the system.

It is a figure for demonstrating the structure of the internal combustion engine system which concerns on each embodiment of this invention. It is sectional drawing which shows the structure of a dehydrogenation reactor. FIG. 3 is a cross-sectional view showing a cross section taken along one-dot chain line I-I ′ of FIG. 2. In Embodiment 1, it is a schematic diagram which shows the relationship between each cylinder of an internal combustion engine, and a dehydrogenation reactor. In Embodiment 2, it is a schematic diagram which shows the relationship between each cylinder of an internal combustion engine, and a dehydrogenation reactor. 6 is a flowchart showing a processing procedure in the hydrogen-utilizing internal combustion engine of the second embodiment. In Embodiment 3, it is a schematic diagram which shows the relationship between each cylinder of an internal combustion engine, and a dehydrogenation reactor. 10 is a flowchart showing a processing procedure in the hydrogen-utilizing internal combustion engine of the third embodiment. 6 is a flowchart showing a processing procedure in the hydrogen-utilizing internal combustion engine of the fourth embodiment.

Explanation of symbols

18 Hydrogen Supply Injector 24 Hydrogenated Gasoline Injector 14, 14a-14h Exhaust Passage 72 Catalyst 82, 84 Switching Valve

Claims (4)

A fuel supply means for supplying an organic hydride-containing fuel to the catalyst;
Hydrogen supply means for supplying hydrogen extracted from the organic hydride-containing fuel to the internal combustion engine by a dehydrogenation reaction on the catalyst,
The internal combustion engine has a plurality of cylinders, and each of the plurality of catalysts in a plurality of exhaust passages provided for each cylinder or each cylinder group is cut off from contact with exhaust gas flowing through the exhaust passages. An internal combustion engine using hydrogen. A hydrogen amount acquisition means for acquiring a hydrogen amount required by the internal combustion engine;
A fuel supply stopping means for stopping supply of the organic hydride-containing fuel to a part of the plurality of catalysts when the amount of hydrogen is a predetermined threshold value or less;
Exhaust gas for supplying exhaust gas flowing through the exhaust passage in which the supply of organic hydride-containing fuel is stopped to the exhaust passage in which the supply of organic hydride-containing fuel is not stopped Supply control means;
The hydrogen-based internal combustion engine according to claim 1, further comprising: A temperature detection means for detecting the temperature of the catalyst;
When the temperature of the catalyst to which the organic hydride-containing fuel is supplied falls below a predetermined threshold value, the supply of the organic hydride-containing fuel to the catalyst is stopped, and the supply of the organic catalyst is stopped. The hydrogen-containing internal combustion engine according to claim 2, wherein a hydride-containing fuel is supplied.   When a predetermined time has elapsed, the supply of the organic hydride-containing fuel to the catalyst to which the organic hydride-containing fuel is supplied is stopped, and the organic hydride-containing fuel is supplied to the catalyst that has been stopped. The hydrogen-utilized internal combustion engine according to claim 2,

Images