JP4677996B2 - Internal combustion engine using hydrogen - Google Patents

Description

  The present invention relates to a hydrogen-utilizing internal combustion engine, and more particularly to a hydrogen-utilizing internal combustion engine having a function of separating hydrogenated fuel into hydrogen and dehydrogenated fuel.

  Conventionally, for example, Japanese Patent Application Laid-Open No. 2005-147124 discloses a system that generates a hydrogen-rich gas and a dehydrogenated fuel by dehydrogenating a hydrogenated fuel containing an organic hydride using a catalyst. According to this system, by supplying only hydrogenated fuel containing organic hydride, three kinds of fuels, hydrogen rich gas, dehydrogenated fuel, and hydrogenated fuel, are used as fuel for operating the internal combustion engine on the vehicle. can do.

Japanese Patent Laying-Open No. 2005-147124 JP 2004-189585 A JP 2005-299501 A JP 2005-299497 A

  By the way, according to the above-described conventional system, the lean burn region of the internal combustion engine can be expanded by adding hydrogen generated on the vehicle to gasoline such as dehydrogenated fuel, thereby improving fuel consumption. A significant effect such as a reduction in the amount of NOx generated can be obtained.

  However, a system that uses exhaust heat to generate hydrogen may not be able to generate hydrogen, such as when the internal combustion engine is cold. Depending on the capacity of the storage tank, there may be a situation where hydrogen is sometimes insufficient. . Therefore, it is conceivable to use hydrogenated fuel as a fuel for an internal combustion engine. However, since hydrogenated fuel has characteristics different from those of ordinary gasoline, the optimum operating region and method are considered in consideration of these characteristics. Etc. need to be selected. In this regard, the above-described conventional technology does not disclose a specific method for using hydrogenated fuel as fuel for an internal combustion engine, and there is room for improvement.

  The present invention has been made to solve the above-described problems, and relates to a hydrogen-utilized internal combustion engine having a function of separating hydrogenated fuel into hydrogen and dehydrogenated fuel, and uses the hydrogenated fuel as fuel for the internal combustion engine. It is intended to achieve high efficiency and low emission while being used.

In order to achieve the above object, a first invention is a hydrogen-utilizing internal combustion engine,
In a hydrogen-based internal combustion engine capable of compression self-ignition operation and spark ignition operation,
Fuel separation means for separating hydrogenated fuel containing organic hydride into hydrogen and dehydrogenated fuel;
Fuel supply means for supplying the internal combustion engine selectively or in combination with any one of the hydrogenated fuel, the hydrogen, and the dehydrogenated fuel;
Control means for performing operation by compression auto-ignition diffusion combustion using the hydrogenated fuel as fuel;
Equipped with a,
When the internal combustion engine is operating in a predetermined operating region, the control means performs an operation by compression auto-ignition diffusion combustion using the hydrogenated fuel as a fuel, and the internal combustion engine is in a lower load region than the predetermined operating region. When the operation is performed with the above, the operation is performed by spark ignition combustion using the dehydrogenated fuel and the hydrogen as fuel .

The second invention is the first invention, wherein
When the internal combustion engine is operated in a lower load region than the operation region where the internal combustion engine is operated using the dehydrogenated fuel and the hydrogen as fuel, the control means is based on compression auto-ignition diffusion combustion using the hydrogenated fuel as a fuel. It is characterized by performing driving.

The third invention is the first or second invention, wherein
Water temperature acquisition means for acquiring the water temperature of the internal combustion engine,
When the water temperature is equal to or lower than a determination value and the internal combustion engine is operated in an operation region based on compression auto-ignition combustion, the control means applies the internal combustion engine to the internal combustion engine prior to supplying the hydrogenated fuel that is fuel. While supplying the said hydrogen, the ignition device arrange | positioned in a combustion chamber is operated, It is characterized by the above-mentioned.

According to the first invention, compression autoignition diffusion combustion using hydrogenated fuel as fuel is performed. Since hydrogenated fuel has a lower octane number than ordinary gasoline (dehydrogenated fuel), it has good self-ignitability. For this reason, according to the present invention, it is possible to achieve both good fuel efficiency and output by compression self-ignition combustion of hydrogenated fuel. Further, hydrogenated fuel has poor knock resistance, but according to the present invention, diffusion fuel is injected at the latter stage of the compression stroke, so that knocking is completely wiped out and exhaust emission is deteriorated. Can be prevented.
Further, according to the present invention, when the internal combustion engine is operated at a relatively high load, compression auto-ignition diffusion combustion using hydrogenated fuel as fuel is performed. Since the self-ignitability is good when the internal combustion engine is operated at a high load, the operation can be performed more efficiently than the operation by premixed spark ignition combustion using dehydrogenated fuel and hydrogen as fuel. For this reason, according to the present invention, high efficiency and low emission can be realized by compression auto-ignition combustion of hydrogenated fuel.

According to the second aspect of the invention, when the internal combustion engine is operated at a relatively low load, compression auto-ignition diffusion combustion using hydrogenated fuel as fuel is performed. When the internal combustion engine is operated at a low load, the intake air can be throttled. For this reason, according to the present invention, it is possible to reduce the dehydrogenation fuel and hydrogen fuel pumping loss, and it is possible to operate more efficiently than the operation by premixed spark ignition combustion using dehydrogenated fuel and hydrogen as fuel. Become. In addition, since the cooling loss is small, fuel consumption can be improved.

In addition, when the internal combustion engine is not warmed up, it is difficult to perform self-ignition combustion during a cold start. According to the third invention, in such a situation, since a small amount of hydrogen is combusted prior to the supply of the hydrogenated fuel, the temperature in the combustion chamber can be effectively increased. For this reason, according to the present invention, even when the internal combustion engine is cold-started, it is possible to reliably perform compression auto-ignition diffusion combustion using hydrogenated fuel as fuel.

  Several embodiments 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.

Embodiment 1 FIG.
[Configuration of Embodiment 1]
FIG. 1 is a diagram for explaining a system configuration according to the first embodiment of the present invention. As shown in FIG. 1, the system of the present embodiment includes an internal combustion engine (hereinafter also referred to as “engine”) 10. The internal combustion engine 10 according to the present embodiment is a spark ignition type four-stroke engine, and includes a spark plug 22 in a combustion chamber 4 formed in the engine body 2. The internal combustion engine 10 self-ignites by injecting fuel into the high-pressure combustion chamber 4 in the later stage of the compression stroke in addition to flame propagation combustion realized by igniting the fuel mixture with the spark plug 22. Has a configuration capable of realizing compression auto-ignition diffusion combustion (hereinafter also referred to as “diesel combustion”) in which combustion is performed while diffusing and mixing with air. More specifically, a variable valve mechanism (not shown) is provided in the intake valve or intake / exhaust valve, and the substantial compression ratio is changed by controlling the valve overlap and intake valve closing timing. It is configured to be possible. When flame propagation combustion is selected as the combustion type, the setting of the variable valve mechanism is set to the low compression ratio side, and when diesel combustion is selected as the combustion type, the setting is changed to the high compression ratio. It has become.

  The internal combustion engine 10 of the present embodiment is a hydrogen-based internal combustion engine that can use gasoline and hydrogen as its fuel. In the present embodiment, gasoline as one fuel is supplied from the outside (for example, a fueling facility such as a gasoline station), whereas hydrogen as the other fuel is generated in the system. ing. More specifically, hydrogen is generated from gasoline by the configuration described below.

  As shown in FIG. 1, an intake pipe 12 and an exhaust pipe 14 communicate with the combustion chamber 4 of the internal combustion engine 10. A throttle valve 16 for controlling the intake air amount is disposed in the intake pipe 12. A hydrogen injection valve 18 is disposed downstream of the throttle valve 16. A gasoline injection valve 20 is disposed downstream of the hydrogen injection valve 18.

  The hydrogen injector 18 is supplied with hydrogen-rich gas at a predetermined pressure, as will be described later. The hydrogen injection valve 18 is opened in response to a drive signal supplied from the outside, so that an amount of hydrogen rich gas corresponding to the valve opening time can be injected into the intake pipe 12.

  As will be described later, gasoline is supplied to the gasoline injection valve 20 at a predetermined pressure. The gasoline injection valve 20 is opened 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 pipe 12.

  A dehydrogenation reactor 24 is arranged in the middle of the exhaust pipe 14. Inside the dehydrogenation reactor 24, a heat exchanger 26 and a dehydrogenation catalyst 28 are arranged. The dehydrogenation reactor 24 is an apparatus that separates hydrogen and gasoline by dehydrogenating hydrogenated gasoline that is a hydrogenated fuel. The dehydrogenation catalyst 28 is further accommodated in a cylindrical casing in the dehydrogenation reactor 24. A temperature sensor 80 that detects the temperature THC of the dehydrogenation catalyst 28 is installed in the vicinity of the dehydrogenation catalyst 28.

  The heat exchanger 26 absorbs the heat of the exhaust gas when the exhaust gas flowing through the exhaust pipe 14 passes through the dehydrogenation reactor 24, and heats the dehydrogenation catalyst 28 using the heat. It is a device that can. Thereby, the dehydrogenation catalyst 28 is heated to a temperature at which dehydrogenation reaction is possible (for example, 300 ° C. or more).

The hydrogenated gasoline in the present embodiment contains a large amount of organic hydride as compared with general gasoline. Here, the “organic hydride” is a hydrocarbon component that causes a dehydrogenation reaction at a temperature of about 300 ° C., and specifically, decalin and cyclohexane correspond to this. Hydrogenated gasoline can be produced, for example, from gasoline. That is, 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, hydrogenated gasoline containing about 40% methylcyclohexane can be produced by hydrogenating toluene contained in ordinary gasoline as a raw material.

  When the hydrogenated gasoline described above is dehydrogenated, hydrogen-rich gas and normal gasoline are generated. In the present embodiment, for convenience of explanation, hydrogenated gasoline having the above-described composition is used as the hydrogenated fuel, and “gasoline” in the present embodiment is generated by a dehydrogenation reaction of hydrogenated gasoline. Equivalent to dehydrogenated fuel.

  As shown in FIG. 1, a hydrogenated gasoline injection valve 30 is disposed above the dehydrogenation catalyst 28. As will be described later, the hydrogenated gasoline injection valve 30 is supplied with hydrogenated gasoline at a predetermined pressure, and is opened by receiving a drive signal received from the outside, so that an amount corresponding to the valve opening time is obtained. The hydrogenated gasoline can be supplied to the dehydrogenation catalyst 28.

  The internal combustion engine 10 is provided with an in-cylinder hydrogenated gasoline injection valve 32 for injecting hydrogenated gasoline into the combustion chamber 4. The above-described hydrogenated gasoline is supplied to the in-cylinder hydrogenated gasoline injection valve 32 at a predetermined pressure. The in-cylinder hydrogenated gasoline injection valve 32 is opened in response to a drive signal supplied from the outside, so that an amount of hydrogenated gasoline corresponding to the valve opening time can be injected into the cylinder.

  The system of the present embodiment includes a hydrogenated gasoline tank 34 that stores hydrogenated gasoline. The hydrogenated gasoline tank 34 is supplied with the hydrogenated gasoline described above. A hydrogenated gasoline supply pipe 36 communicates with the hydrogenated gasoline tank 34. The hydrogenated gasoline supply pipe 36 includes a pump (not shown) in the middle thereof, and communicates with the hydrogenated gasoline injection valve 30 and the in-cylinder hydrogenated gasoline injection valve 32 at the end thereof. The hydrogenated gasoline in the hydrogenated gasoline tank 34 is pumped up by a pump during operation of the internal combustion engine 10 and supplied to the hydrogenated gasoline injection valve 30 or the in-cylinder hydrogenated gasoline injection valve 32 at a predetermined pressure. Thereby, the hydrogenated gasoline in the hydrogenated gasoline tank 34 can be injected from the hydrogenated gasoline injection valve 30 or can be injected from the in-cylinder hydrogenated gasoline injection valve 32.

  One end of a pipe line 38 is connected to the lower part of the dehydrogenation catalyst 28. The other end of the pipe line 38 communicates with the separation device 40. The mixture of the hydrogen-rich gas and gasoline generated in the dehydrogenation catalyst 28 flows into the separation device 40 through the pipe line 38.

  The separation device 40 has a function of cooling the high-temperature hydrogen-rich gas and gasoline supplied from the dehydrogenation catalyst 28 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 hydrogen-rich gas and gasoline efficiently.

  A liquid storage space for storing 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 tank 48. A gasoline supply pipe 50 communicates with the gasoline tank 48. The gasoline supply pipe 50 is provided with a pump (not shown) in the middle thereof, and communicates with the gasoline injection valve 20 at its end. Gasoline in the gasoline tank is pumped up by a pump during operation of the internal combustion engine 10 and supplied to the gasoline injection valve 20 at a predetermined pressure.

  The hydrogen pipe 44 communicates with the hydrogen tank 52. Further, a pump (not shown) for pumping the hydrogen rich gas in the separation device 40 to the hydrogen tank 52 is incorporated in the hydrogen pipe 44. A hydrogen supply pipe 54 communicates with the hydrogen tank 52. The hydrogen supply pipe is provided with a regulator (not shown) in the middle thereof and communicates with the hydrogen injection valve 18 at its end. According to such a configuration, the hydrogen injector 18 is supplied with the hydrogen rich gas by the pressure regulated by the regulator on the condition that the hydrogen rich gas is stored in the hydrogen tank 52.

  The system according to the present embodiment includes an ECU (Electronic Control Unit) 70. Overall control of the internal combustion engine 10 is performed by the ECU 70. In addition to the hydrogen injector 18, gasoline injector 20, hydrogenated gasoline injector 30, in-cylinder hydrogenated gasoline injector 32, various devices (not shown) such as a pump are connected to the output portion of the ECU 70. . Various inputs such as an engine speed sensor 72, an accelerator opening sensor 74, a vehicle speed sensor 76, a temperature sensor 78 that detects the temperature of the cooling water, and a temperature sensor 80 that detects the temperature of the dehydrogenation catalyst 28 are input to the ECU 70. Sensors are connected. Engine speed NE (rpm), accelerator opening ACCP (%), vehicle speed SPD (m / s), water temperature THW (° C), catalyst temperature THC (° C) input from these sensors 72, 74, 76, 78, 80 ) Is used as information related to engine control. The ECU 70 drives each device in accordance with a predetermined program based on various types of input information.

[Operation in Embodiment 1]
Next, the operation of the first embodiment will be described. The system according to the present embodiment is based on the operation state of the internal combustion engine 10 and is operated by diesel combustion of hydrogenated gasoline (hereinafter referred to as “diesel combustion operation”) and lean burn performed by adding hydrogen rich gas to gasoline. Operation (hereinafter referred to as hydrogen addition lean burn operation) can be selected.

  During the hydrogen addition lean burn operation, hydrogen and gasoline production operations in the dehydrogenation catalyst 28 and combustion operations of these fuels are executed. More specifically, in the system of the present embodiment, when the temperature of the dehydrogenation catalyst 28 in the dehydrogenation reactor 24 reaches about 300 ° C., the hydrogenated gasoline can be separated into hydrogen-rich gas and gasoline. After starting the internal combustion engine 10, the ECU 70 determines whether or not the dehydrogenation reactor 24 is ready to perform the separation process based on the output of the temperature sensor 80. When it is determined that the process can be performed, the hydrogenated gasoline injection valve 30 starts to inject an appropriate amount of hydrogenated gasoline.

  When injection of hydrogenated gasoline is started in this way, high-temperature gas in which hydrogen-rich gas and gasoline are mixed begins to flow out from the bottom of the dehydrogenation reactor 24. When this high-temperature gas is cooled by the separator 40, gasoline starts to flow through the gasoline pipe 42 and hydrogen-rich gas starts to flow through the hydrogen pipe 44. Thereby, gasoline and hydrogen rich gas are supplied to the gasoline tank 48 and the hydrogen tank 52, respectively.

  Further, during the hydrogen addition lean burn operation, the hydrogen rich gas in the hydrogen tank 52 is supplied to the hydrogen injection valve 18 through the hydrogen supply pipe 54. At the same time, gasoline stored in the gasoline tank 48 is supplied to the gasoline injection valve 20 through the gasoline supply pipe 50. Gasoline is injected into the intake pipe 12 by the operation of the gasoline injection valve 20, and hydrogen rich gas is injected into the intake pipe 12 by the operation of the hydrogen injection valve 18. The hydrogen-rich gas and gasoline injected into the intake pipe 12 are sucked into the combustion chamber 4 while being mixed with air, and burned (flame propagation combustion) by being ignited by the spark plug 22.

  On the other hand, during diesel combustion operation, hydrogenated gasoline stored in the hydrogenated gasoline tank 34 is supplied to the in-cylinder hydrogenated gasoline injection valve 32 via the hydrogenated gasoline supply pipe 36. During the diesel combustion operation, only the in-cylinder hydrogenated gasoline injection valve 32 operates, and hydrogenated gasoline is injected into the combustion chamber 4 at the latter stage of the compression stroke. Hydrogenated gasolines based on naphthenic hydrocarbons such as methylcyclohexane are suitable for diesel combustion because they have lower octane numbers and are easier to ignite at lower temperatures than gasolines based on aromatic hydrocarbons such as toluene. ing. In the latter stage of the compression stroke, the inside of the combustion chamber 4 is at high temperature and pressure. For this reason, the hydrogenated gasoline injected into the combustion chamber 4 self-ignites and starts combustion, and the hydrogenated gasoline is continuously injected, so that the hydrogenated gasoline burns while being diffusely mixed with air. To do.

  Of the two operation methods that can be executed in the engine according to the present embodiment, according to the hydrogen-added lean burn operation, the lean burn operation using only gasoline as fuel is performed by adding a hydrogen-rich gas with excellent combustibility. As a result, the air-fuel ratio can be made leaner, and the fuel consumption can be further improved and the amount of NOx generated can be reduced.

  However, in the hydrogen addition lean burn operation, there is a possibility that knocking in a high load region may occur, and in such a case, there is a concern about deterioration of fuel consumption and exhaust emission. In addition, in order to perform the hydrogen addition lean burn operation, naturally, a hydrogen rich gas is required, and in a situation where the hydrogen rich gas is insufficient, the hydrogen addition lean burn operation cannot be performed. In the case of a system that generates hydrogen rich gas by dehydrogenating hydrogenated gasoline as in the present embodiment, in a low load region where the exhaust heat of the engine is low and the dehydrogenation catalyst 28 cannot be heated sufficiently, There is a possibility that an amount of hydrogen rich gas necessary for the hydrogen addition lean burn operation cannot be generated.

  On the other hand, according to the diesel combustion operation, knocking can be completely wiped out even in a high load region by using hydrogenated fuel excellent in self-ignitability, so that both good fuel consumption and output can be achieved. be able to. In addition, since the intake air can be throttled in the low load range, the pumping loss and the cooling loss can be reduced, and the fuel efficiency can be improved.

  Therefore, in the system according to the present embodiment, the engine operation method is selected according to the engine operation region according to the map of FIG. The map of FIG. 2 is a multi-dimensional map with the engine load and the engine speed as axes, and the low load region and the high load region of the engine operation region are set as regions where diesel combustion operation is performed, and the medium load region Is set in the region where the hydrogen addition lean burn operation is performed.

  In the map of FIG. 2, the boundary between the operation region in which the low load diesel combustion operation is selected and the operation region in which the hydrogen addition lean burn operation is selected indicates that the low load diesel combustion operation is more effective than the hydrogen addition lean burn operation. It means a limit load with high efficiency. In addition, the boundary between the operation range in which high-load diesel combustion operation is selected and the operation region in which hydrogen-added lean burn operation is selected is the limit that high-load diesel combustion operation is more efficient than hydrogen-added lean burn operation. Means load.

  According to the map of FIG. 2, the low load region where the hydrogen addition lean burn operation becomes difficult due to the lack of the hydrogen rich gas can be supplemented by the low load diesel combustion. Moreover, the high load region where the hydrogen addition lean burn operation becomes difficult due to the occurrence of knocking can be supplemented by high load diesel combustion. Therefore, by switching the operation method of the engine according to the map of FIG. 2, high efficiency and low emission can be realized in a wide operation region while using hydrogenated gasoline as a fuel for the internal combustion engine 10.

[Specific Processing in Embodiment 1]
Next, with reference to FIG. 3, the specific content of the process performed in this Embodiment is demonstrated. FIG. 3 is a flowchart of a routine in which the ECU 70 executes fuel injection control.

  In the routine shown in FIG. 3, first, the operating state of the internal combustion engine 10 is input (step 100). Specifically, specifically, the engine speed NE detected from the rotation signal of the rotation speed sensor 72, the accelerator opening ACCP detected from the output signal of the accelerator opening sensor 74, the vehicle speed SPD detected from the vehicle speed sensor, The engine load calculated from these values, the water temperature THW detected from the temperature sensor 78, and the like are input as the operating state of the internal combustion engine 10.

  Next, the storage amount of each fuel is input (step 102). Here, specifically, the stored fuel amounts are respectively detected based on the output signals of the liquid amount sensors provided in the hydrogenated gasoline tank 34, the hydrogen tank 52, and the gasoline tank 48.

  Next, it is determined whether or not the amount of gasoline stored exceeds the lower limit value V1 (step 104). Specifically, the gasoline storage amount input in step 102 is compared with a predetermined lower limit value V1. As the lower limit value V1, a value set in advance is used as the minimum storage amount of gasoline that can be subjected to the hydrogen addition lean burn operation.

  As a result, if establishment of gasoline storage amount> lower limit value V1 is not confirmed, it is determined that the hydrogen-added lean burn operation of gasoline cannot be executed, and the routine proceeds to the next step, where diesel combustion of hydrogenated gasoline is performed. Operation is performed (step 106).

  On the other hand, in the above step 104, when it is recognized that the gasoline storage amount> the lower limit value V1 is established, the process proceeds to the next step, and whether or not the engine load in the current operation state is in the high load diesel combustion operation region. Determination is made (step 108). Here, specifically, it is determined whether or not the operating state acquired in step 100 belongs to a region where a high-load diesel combustion operation is selected in the map shown in FIG. As a result, when it is determined that the high-load diesel operation belongs to the region to be selected, the process proceeds to step 106, and the diesel combustion operation is executed.

  On the other hand, if it is determined in step 108 that the high load diesel operation does not belong to the selected region, the process proceeds to the next step, and the engine load in the current operation state is low load diesel combustion operation. It is determined whether it is an area (step 110). Here, specifically, it is determined whether or not the operating state acquired in step 100 belongs to a region where a low-load diesel combustion operation is selected in the map shown in FIG. As a result, when it is determined that the low-load diesel operation belongs to the selected region, the process proceeds to step 106, and the diesel combustion operation is executed. On the other hand, when it is determined that the low-load diesel operation does not belong to the selected region, the process proceeds to the next step, and the gasoline hydrogen addition lean burn operation is executed (step 112).

  As described above, according to the first embodiment, it is possible to supplement the low load region in which the hydrogen addition lean burn operation becomes difficult due to the lack of the hydrogen rich gas by the low load diesel combustion. Moreover, the high load region where the hydrogen addition lean burn operation becomes difficult due to the occurrence of knocking can be supplemented by high load diesel combustion. Therefore, high efficiency and low emission can be realized in a wide range of operation while using hydrogenated gasoline as fuel for the engine.

  By the way, in Embodiment 1 mentioned above, it is supposed that the hydrogen injection valve 18 is arrange | positioned in the intake pipe 12, However, The arrangement | positioning is not limited to this. That is, the hydrogen injection valve 18 may be incorporated in the engine body 2 so that hydrogen can be injected into the cylinder. Further, the arrangement of the gasoline injection valve 20 is not limited to the intake pipe 12 and may be incorporated in the engine body 2 so that hydrogen can be injected into the cylinder. This also applies to other embodiments described below.

  In the first embodiment described above, hydrogenated gasoline produced by hydrogenating gasoline is used as the hydrogenated fuel containing organic hydride. However, the hydrogenated fuel to be used is limited to this. Absent. That is, it may be a hydrogenated fuel produced by reforming or blending a fraction containing a large amount of organic hydride components. Further, the organic hydride contained in the hydrogenated fuel is not limited to methylcyclohexane, and may be decalin or cyclohexane. Further, the content ratio of the organic hydride in the hydrogenated fuel is not particularly limited as long as it is higher than that of ordinary gasoline. This also applies to other embodiments described below.

  In Embodiment 1 described above, the hydrogen addition lean burn operation is selected in the medium load region, but the operation selected in this region is not limited to the lean burn operation. That is, in the hydrogen addition lean burn operation, the knocking resistance deteriorates as the engine load increases. For this reason, it is good also as performing the stoichiometric or rich operation by hydrogen addition in the high load side in a middle load region, and performing the combustion which suppressed generation of knocking. In this case, the operation region in which the high-load diesel combustion operation is selected may be bounded by a limit load at which the high-load diesel combustion operation is more efficient than the hydrogen addition stoichiometric (or rich) operation.

  In the first embodiment described above, hydrogenated gasoline is the “hydrogenated fuel” in the first invention, gasoline is the “dehydrogenated fuel” in the first invention, and the dehydrogenation reactor 24 is the first hydrogenated fuel. This corresponds to the “fuel separation means” in the first invention. Further, the “control means” according to the first aspect of the present invention is realized by the ECU 70 executing the processing of step 106 described above.

In the first embodiment described above, the “control means” according to the first aspect of the present invention is implemented when the ECU 70 executes the process of step 112.

In the first embodiment described above, the “control means” according to the second aspect of the present invention is realized by the ECU 70 executing the process of step 106.

Embodiment 2. FIG.
[Features of Embodiment 2]
Next, a second embodiment of the present invention will be described with reference to FIG. The system of the present embodiment can be realized by causing the ECU 70 to execute a routine shown in FIG. 4 to be described later using the hardware configuration shown in FIG.

  In the first embodiment described above, the operation by diesel combustion of hydrogenated gasoline is performed in a predetermined operation region. As described above in Embodiment 1, hydrogenated gasoline mainly composed of naphthenic hydrocarbons such as methylcyclohexane has a lower octane number than gasoline mainly composed of aromatic hydrocarbons such as toluene and ignites at a lower temperature. It has the characteristic that it is easy to do. However, under operating conditions such as when the engine is cold started, it is assumed that the combustion chamber 4 does not reach the pressure and temperature at which hydrogenated gasoline can self-ignite, and the emission deteriorates due to misfire.

  Therefore, in the second embodiment, at the time of cold start of the internal combustion engine 10, prior to the injection of hydrogenated gasoline in the combustion cycle, self-ignition assistance is performed in which a small amount of hydrogen rich gas is combusted in the combustion chamber 4. And Specifically, first, the hydrogen rich gas stored in the hydrogen tank 52 is supplied to the hydrogen injection valve 18 through the hydrogen supply pipe 54. In the intake stroke, a very small amount of hydrogen rich gas is injected into the intake pipe 12 by the operation of the hydrogen injection valve 18 for a very short time. The hydrogen-rich gas injected into the intake pipe 12 is sucked into the combustion chamber 4 while being mixed with air. Then, in the first half of the compression stroke, the ignition of the spark plug 22 burns hydrogen-rich gas with excellent combustibility. Thereby, the temperature in the combustion chamber 4 can be raised.

  In the latter half of the compression stroke, only the in-cylinder hydrogenated gasoline injection valve 32 operates, and hydrogenated gasoline is injected into the high-pressure combustion chamber 4. At this time, the temperature in the combustion chamber 4 has increased due to the combustion of the hydrogen-rich gas immediately before. For this reason, the injected hydrogenated gasoline can be surely self-ignited, and emission deterioration due to misfire can be effectively suppressed.

[Specific Processing in Second Embodiment]
Next, with reference to FIG. 4, the specific content of the process performed in this Embodiment is demonstrated. FIG. 4 is a flowchart of a routine in which the ECU 70 performs fuel injection control when the diesel combustion operation is executed.

  In the routine shown in FIG. 4, first, the operating state of the internal combustion engine 10 is input (step 200). Next, the storage amount of each fuel is input (step 202). Here, specifically, the same processing as in steps 100 and 102 is executed.

  Next, it is determined whether or not the coolant temperature THW is smaller than a determination value T1 (step 204). Specifically, the magnitude of the coolant temperature THW input in step 200 is compared with the determination value T1 for determining the warm-up state of the internal combustion engine 10. As the determination value T1, a value set in advance as a water temperature at which the warm-up of the internal combustion engine 10 is completed is used.

  As a result, when the establishment of the water temperature THW <the determination value T1 is recognized, the process proceeds to the next step, and diesel combustion with self-ignition assistance by hydrogen combustion is executed (step 206). On the other hand, if the establishment of the water temperature THW <determination value T1 is not recognized in step 204, it is determined that the internal combustion engine 10 has been warmed up and that self-ignition assistance is not required, and the next step is performed. The routine proceeds to normal hydrogenated gasoline diesel combustion (step 208).

  As described above, according to the second embodiment, in the diesel combustion of hydrogenated gasoline, even if it is an operation condition that is difficult to self-ignite, such as at the time of cold start of the internal combustion engine 10, it is possible to surely self-ignite. it can. Thereby, the efficiency fall and emission deterioration by misfire can be suppressed effectively.

  In the second embodiment described above, the ignition plug 22 is used as an ignition device for igniting the hydrogen-rich gas at the time of self-ignition assist combustion by hydrogen addition, but a dedicated ignition device is provided separately from the ignition plug 22. It is good also as a structure.

  In the second embodiment described above, hydrogenated gasoline is the “hydrogenated fuel” in the first invention, gasoline is the “dehydrogenated fuel” in the first invention, and the dehydrogenation reactor 24 is the first hydrogenated fuel. This corresponds to the “fuel separation means” in the present invention. Further, the “control means” according to the first aspect of the present invention is realized by the ECU 70 executing the processing of step 206 or 208 described above.

In the first embodiment described above, the spark plug 22 corresponds to the “ignition device” in the first invention, and the temperature sensor 78 corresponds to the “water temperature acquisition means” in the third invention. Further, the “control means” according to the third aspect of the present invention is realized by the ECU 70 executing the process of step 206 described above.

Embodiment 3 FIG.
[Features of Embodiment 3]
Next, a third embodiment of the present invention will be described with reference to FIGS. The system of the present embodiment can be realized by causing the ECU 70 to execute a routine shown in FIG. 6 to be described later using the hardware configuration shown in FIG. However, the internal combustion engine 10 of the present embodiment is a low compression ratio spark ignition type four-stroke engine, and has a configuration capable of realizing only flame propagation combustion realized by igniting a fuel mixture with an ignition plug 22. is doing.

  The system of the present embodiment is based on the operation state of the internal combustion engine 10 based on the operation of hydrogenated gasoline by flame propagation combustion (hereinafter referred to as “hydrogenated gasoline operation”) and the operation of gasoline by flame propagation combustion (hereinafter referred to as “hydrogenated gasoline operation”). , "Gasoline operation") and hydrogen-added lean burn operation performed by adding a hydrogen rich gas to gasoline.

  During the hydrogen addition lean burn operation, the hydrogen rich gas in the hydrogen tank 52 is supplied to the hydrogen injector 18 through the hydrogen supply pipe 54. At the same time, gasoline stored in the gasoline tank 48 is supplied to the gasoline injection valve 20 through the gasoline supply pipe 50. Gasoline is injected into the intake pipe 12 by the operation of the gasoline injection valve 20, and hydrogen rich gas is injected into the intake pipe 12 by the operation of the hydrogen injection valve 18. The hydrogen-rich gas and gasoline injected into the intake pipe 12 are sucked into the combustion chamber 4 while being mixed with air, and burned (flame propagation combustion) by being ignited by the spark plug 22.

  On the other hand, during the hydrogenated gasoline operation, the hydrogenated gasoline stored in the hydrogenated gasoline tank 34 is supplied to the in-cylinder hydrogenated gasoline injection valve 32 via the hydrogenated gasoline supply pipe 36. During the hydrogenated gasoline operation, only the in-cylinder hydrogenated gasoline injection valve 32 operates, and hydrogenated gasoline is injected into the combustion chamber 4 at an early stage of the intake stroke. The injected hydrogenated gasoline is mixed with air in the combustion chamber 4 and burned (flame propagation combustion) by being ignited by the spark plug 22.

  Further, during gasoline operation, gasoline stored in the gasoline tank 48 is supplied to the gasoline injection valve 20 through the gasoline supply pipe 50. During gasoline operation, only the gasoline injection valve 20 operates and gasoline is injected into the intake pipe 12. The gasoline injected into the intake pipe 12 is sucked into the combustion chamber 4 while being mixed with air, and burned (flame propagation combustion) by being ignited by the spark plug 22.

  Further, during the hydrogen-added lean burn operation and the gasoline operation, in addition to the combustion operation of these fuels, the operation of generating hydrogen and gasoline in the dehydrogenation catalyst 28 is executed. Since this operation is the same as that described in the first embodiment, detailed description thereof is omitted.

  Among the three operation methods that can be executed in the engine according to the present embodiment, according to the hydrogen addition lean burn operation, the lean burn operation using only gasoline as fuel is performed by adding a hydrogen rich gas with excellent combustibility. As a result, the air-fuel ratio can be made leaner, and the fuel consumption can be further improved and the amount of NOx generated can be reduced. However, in order to perform the hydrogen-added lean burn operation, naturally, a hydrogen-rich gas is required, and the hydrogen-added lean burn operation cannot be performed in a situation where the hydrogen-rich gas is insufficient. In the case of a system that generates hydrogen rich gas by dehydrogenating hydrogenated gasoline as in the present embodiment, in a low load region where the exhaust heat of the engine is low and the dehydrogenation catalyst 28 cannot be heated sufficiently, There is a possibility that an amount of hydrogen rich gas necessary for the hydrogen addition lean burn operation cannot be generated.

  On the other hand, according to hydrogenated gasoline operation, hydrogenated gasoline can be burned and operated even in a situation where hydrogen rich gas or gasoline is insufficient. However, hydrogenated gasolines based on naphthenic hydrocarbons such as methylcyclohexane have a lower octane number and are easier to ignite at lower temperatures than gasolines based on aromatic hydrocarbons such as toluene. Is bad. For this reason, in hydrogenated gasoline operation, there is a possibility of knocking in a high load region, and in such a case, there is a concern about deterioration of fuel consumption and exhaust emission.

  Therefore, in the system according to the present embodiment, an engine operation method is selected according to the engine operation region according to the map of FIG. The map in FIG. 5 is a multi-dimensional map with the engine load and the engine speed as axes. The low load range is set as the hydrogenated gasoline operation range and the medium load range is the gasoline operation range. The high load region is set to the region where the hydrogen addition lean burn operation is performed.

  In the map of FIG. 5, the boundary between the operation region in which low-load hydrogenated gasoline operation is selected and the operation region in which gasoline operation is selected is the limit at which flame propagation combustion with hydrogenated gasoline becomes difficult due to occurrence of knocking. Means load. In addition, the boundary between the operation range in which medium-load gasoline combustion operation is selected and the operation region in which high-load hydrogen addition lean burn operation is selected indicates that the high load hydrogen addition lean burn operation is more efficient than gasoline operation. It means a good limit load.

  According to the map of FIG. 5, hydrogenated gasoline can be used to the maximum extent that knocking does not occur. Therefore, by switching the engine operation method according to the map of FIG. 5, it is possible to achieve high efficiency and low emission in a wide range of operation while using hydrogenated gasoline.

[Specific Processing in Embodiment 3]
Next, with reference to FIG. 6, the specific content of the process performed in this Embodiment is demonstrated. FIG. 6 is a flowchart of a routine in which the ECU 70 executes fuel injection control.

  In the routine shown in FIG. 6, first, the operating state of the internal combustion engine 10 is input (step 300). Here, specifically, the same processing as in step 100 is executed. Next, it is determined whether or not the engine load in the current operating state is in the hydrogenated gasoline operating region (step 302). Here, specifically, it is determined whether or not the operating state acquired in step 300 belongs to a region in which hydrogenated gasoline operation is selected in the map shown in FIG. As a result, when it is determined that the hydrogenated gasoline operation belongs to the selected region, the process proceeds to the next step, and the hydrogenated gasoline operation is executed (step 304).

  On the other hand, if it is determined in step 302 that the hydrogenated gasoline operation does not belong to the selected region, the process proceeds to the next step, where the engine load in the current operation state is the hydrogenated lean burn operation region. It is determined whether or not (step 306). Specifically, it is determined whether or not the operating state acquired in step 300 belongs to a region where the hydrogen addition lean burn operation is selected in the map shown in FIG. As a result, when it is determined that the hydrogen addition lean burn operation belongs to the selected region, the process proceeds to the next step and the gasoline hydrogen addition lean burn operation is executed (step 308). On the other hand, if it is determined in step 306 that the hydrogen addition lean burn operation does not belong to the selected region, the process proceeds to the next step and the gasoline operation is executed (step 310).

  As described above, according to the third embodiment, in a region where knocking occurs due to hydrogenated gasoline, hydrogenated gasoline operation is prohibited and premixed spark ignition combustion using gasoline is performed. It can be effectively prevented. Moreover, the low load region in which the hydrogen addition lean burn operation becomes difficult due to the lack of the hydrogen rich gas can be supplemented by flame propagation combustion with hydrogenated gasoline. Therefore, high efficiency and low emission can be realized in a wide range of operation while using hydrogenated gasoline as engine fuel.

  Incidentally, in Embodiment 3 described above, the in-cylinder hydrogenated gasoline injection valve 32 is incorporated in the engine body 2 so that hydrogenated gasoline can be directly injected into the combustion chamber 4, but the arrangement is limited to this. Is not to be done. That is, the in-cylinder hydrogenated gasoline injection valve 32 may be disposed in the intake pipe 12 so that hydrogenated gasoline is injected into the intake pipe 12 and is sucked into the combustion chamber 4 while being mixed with air.

  In the above-described third embodiment, the hydrogenated lean burn operation or gasoline operation of gasoline is executed in a region other than the hydrogenated gasoline operation region, but the selected operation is limited to this. Absent. That is, as long as the knocking resistance can be improved as compared with the hydrogenated gasoline operation, another operation may be selected and executed according to the operation state.

Embodiment 4 FIG.
[Features of Embodiment 4]
Next, a fourth embodiment of the present invention will be described with reference to FIGS. The system of the present embodiment can be realized by causing the ECU 70 to execute a routine shown in FIG. 8 to be described later using the hardware configuration shown in FIG. However, the internal combustion engine 10 according to the present embodiment can realize HCCI (Homogeneous Change Compression Ignition) combustion not based on flame propagation in addition to flame propagation combustion realized by igniting the fuel mixture with the spark plug 22. It has a configuration. More specifically, a variable valve mechanism (not shown) is provided in the intake valve or intake / exhaust valve, and the substantial compression ratio is changed by controlling the valve overlap and intake valve closing timing. It is configured to be possible. When flame propagation combustion is selected as the combustion type, the setting of the variable valve mechanism is set to the low compression ratio side, and when HCCI combustion is selected as the combustion type, the setting is changed to the high compression ratio. It has become.

  The system of the present embodiment includes a hydrogen addition lean burn operation performed by adding a hydrogen rich gas to gasoline, an operation by HCCI combustion of gasoline (hereinafter referred to as “gasoline HCCI combustion operation”), hydrogen, To select the operation by HCCI combustion of hydrogenated gasoline (hereinafter referred to as “hydrogenated gasoline HCCI combustion operation”) and the operation by flame propagation combustion of gasoline and hydrogenated gasoline (hereinafter referred to as “mixed gasoline operation”). Can do.

  During the hydrogen addition lean burn operation, the hydrogen rich gas in the hydrogen tank 52 is supplied to the hydrogen injector 18 through the hydrogen supply pipe 54. At the same time, gasoline stored in the gasoline tank 48 is supplied to the gasoline injection valve 20 through the gasoline supply pipe 50. Gasoline is injected into the intake pipe 12 by the operation of the gasoline injection valve 20, and hydrogen rich gas is injected into the intake pipe 12 by the operation of the hydrogen injection valve 18. The hydrogen-rich gas and gasoline injected into the intake pipe 12 are sucked into the combustion chamber 4 while being mixed with air, and burned (flame propagation combustion) by being ignited by the spark plug 22.

  On the other hand, during gasoline HCCI operation, gasoline stored in the gasoline tank 48 is supplied to the gasoline injection valve 20 via the gasoline supply pipe 50. During gasoline HCCI operation, only the gasoline injection valve 20 is operated, and gasoline is injected into the intake pipe 12. The injected gasoline is mixed with air, sucked into the combustion chamber 4, and compressed to self-ignite and burn.

  Further, during the hydrogenated gasoline HCCI operation, the hydrogenated gasoline stored in the hydrogenated gasoline tank 34 is supplied to the in-cylinder hydrogenated gasoline injection valve 32 via the hydrogenated gasoline supply pipe 36. During the hydrogenated gasoline operation, only the in-cylinder hydrogenated gasoline injection valve 32 operates, and hydrogenated gasoline is injected into the combustion chamber 4 at an early stage of the intake stroke. Hydrogenated gasoline containing naphthenic hydrocarbons such as methylcyclohexane as the main component has a lower octane number and is easier to ignite at lower temperatures than gasoline containing mainly aromatic hydrocarbons such as toluene, so it is suitable for HCCI combustion. ing. The injected hydrogenated gasoline mixes with air in the combustion chamber 4 and is compressed to self-ignite and burn.

  Further, during the mixed gasoline operation, the gasoline stored in the gasoline tank 48 is supplied to the gasoline injection valve 20 through the gasoline supply pipe 50. Further, the hydrogenated gasoline stored in the hydrogenated gasoline tank 34 is supplied to the in-cylinder hydrogenated gasoline injection valve 32 through the hydrogenated gasoline supply pipe 36. During the mixed gasoline operation, the gasoline injection valve 20 and the in-cylinder hydrogenated gasoline injection valve are operated, and gasoline and hydrogenated gasoline are injected into the intake pipe 12. Gasoline and hydrogenated gasoline injected into the intake pipe 12 are sucked into the combustion chamber 4 while being mixed with air, and burned (flame propagation combustion) by being ignited by the spark plug 22.

  Further, during the hydrogen addition lean burn operation and the gasoline HCCI operation, in addition to the combustion operation of these fuels, the dehydrogenation catalyst 28 generates hydrogen and gasoline. Since this operation is the same as that described in the first embodiment, detailed description thereof is omitted.

  Of the four operating methods that can be executed in the engine according to the present embodiment, according to the hydrogen-added lean burn operation, the lean burn operation using only gasoline as fuel is performed by adding a hydrogen-rich gas with excellent combustibility. As a result, the air-fuel ratio can be made leaner, and the fuel consumption can be further improved and the amount of NOx generated can be reduced. In addition, in the present embodiment, more stable combustion at a high load is possible by using gasoline (dehydrogenated gasoline) having a high octane number instead of hydrogenated gasoline as a raw fuel.

  However, in the hydrogen addition lean burn operation, the hydrogen addition lean burn operation naturally requires a hydrogen rich gas, and the hydrogen addition lean burn operation cannot be executed in a situation where the hydrogen rich gas is insufficient. . In the case of a system that generates hydrogen rich gas by dehydrogenating hydrogenated gasoline as in the present embodiment, in a low load region where the exhaust heat of the engine is low and the dehydrogenation catalyst 28 cannot be heated sufficiently, There is a possibility that an amount of hydrogen rich gas necessary for the hydrogen addition lean burn operation cannot be generated.

  On the other hand, according to the HCCI combustion operation, an ultra-lean air-fuel mixture that exceeds the combustion limit of flame propagation combustion can be burned. Thereby, it is possible to further reduce the amount of NOx produced and to achieve higher thermal efficiency than the hydrogen addition lean burn operation which is one form of flame propagation combustion. In particular, in the hydrogenated gasoline HCCI operation in the present embodiment, hydrogenated gasoline having a low octane number and easily ignited at a low temperature is used as a fuel, so that stable HCCI combustion in a low load range is possible.

  However, on the other hand, in the HCCI combustion, when the engine load becomes higher, the generation of combustion noise becomes remarkable, so that it is difficult to execute the HCCI combustion in a high load region. On the other hand, when the engine load decreases to an extremely low load range, the compression ratio decreases and the self-ignitability deteriorates, so that it is difficult to execute HCCI combustion.

  Therefore, in the system according to the present embodiment, the engine operation method is selected according to the engine operation region according to the map of FIG. The map in FIG. 7 is a multi-dimensional map with the engine load and the engine speed as axes. The engine load range is lower than the set hydrogenated gasoline HCCI combustion operation range, and the mixed gasoline operation is performed. The high load region is set as a region where HCCI combustion operation using gasoline is performed, and the high load region is set as a region where hydrogen addition lean burn operation is performed.

  In the map of FIG. 7, the boundary between the operation region where the mixed gasoline operation is selected and the operation region where the hydrogenated gasoline HCCI combustion operation is selected means a limit load at which HCCI combustion using hydrogenated gasoline becomes difficult. Yes. Further, the boundary between the operation region in which the HCCI combustion operation using gasoline is selected and the operation region in which the hydrogen addition lean burn operation is selected means a limit load that makes HCCI combustion using gasoline difficult. Further, the boundary between the HCCI combustion operation using hydrogenated gasoline and the HCCI combustion operation using gasoline means a limit load that makes hydrogenated gasoline HCCI combustion difficult.

  That is, the map of FIG. 7 is as wide as possible by giving priority to the hydrogenated gasoline HCCI combustion operation over the mixed gasoline operation and giving priority to the gasoline HCCI combustion operation over the hydrogenated lean burn operation. It is created so that the HCCI combustion operation is selected in the operation region. This is because, when comparing the HCCI combustion operation with the hydrogen addition lean burn operation and the mixed gasoline operation, the HCCI combustion operation has higher thermal efficiency than the hydrogen addition lean burn operation and the mixed gasoline operation, and the amount of NOx generated This is because it can be suppressed to an extremely low level.

  According to the map of FIG. 7, the low load region where the hydrogenated gasoline HCCI combustion operation becomes difficult due to the decrease in the compression ratio can be supplemented by flame propagation combustion with the mixed gasoline. In addition, the intermediate load range in which hydrogenated gasoline HCCI combustion operation becomes difficult due to the occurrence of knocking can be supplemented by gasoline HCCI combustion. Moreover, the high load region where the gasoline HCCI combustion operation becomes difficult due to the generation of combustion noise can be supplemented by gasoline HCCI combustion. Therefore, by switching the engine operation method according to the map of FIG. 7, it is possible to achieve high efficiency and low emission in a wide range of operation while using hydrogenated gasoline as engine fuel.

[Specific Processing in Embodiment 4]
Next, with reference to FIG. 8, the specific content of the process performed in this Embodiment is demonstrated. FIG. 8 is a flowchart of a routine in which the ECU 70 executes fuel injection control.

  In the routine shown in FIG. 8, first, the operating state of the internal combustion engine 10 is input (step 400). Here, specifically, the same processing as in step 100 is executed. Next, it is determined whether or not the engine load in the current operation state is in the hydrogen addition lean burn operation region (step 402). Here, specifically, it is determined whether or not the operating state acquired in step 400 belongs to a region where the hydrogen addition lean burn operation is selected in the map shown in FIG. As a result, when it is determined that the hydrogen addition lean burn operation belongs to the selected region, the process proceeds to the next step, and the hydrogen addition lean burn operation is executed (step 404).

  On the other hand, when it is determined in step 402 that the hydrogenated gasoline operation does not belong to the selected region, the process proceeds to the next step, and whether or not the engine load in the current operation state is the gasoline HCCI combustion operation region. Is determined (step 406). Here, specifically, it is determined whether or not the operating state acquired in step 300 belongs to a region where the gasoline HCCI combustion operation is selected in the map shown in FIG. As a result, when it is determined that the gasoline HCCI combustion operation belongs to the selected region, the process proceeds to the next step and the gasoline HCCI combustion operation is executed (step 408).

  On the other hand, when it is determined in step 406 that the gasoline HCCI combustion operation does not belong to the selected region, the process proceeds to the next step, and the engine load in the current operation state is the hydrogenated gasoline HCCI combustion operation region. Is determined (step 410). Here, specifically, it is determined whether or not the operating state acquired in step 300 belongs to a region in which the hydrogenated gasoline HCCI combustion operation is selected in the map shown in FIG. As a result, when it is determined that the hydrogenated gasoline HCCI combustion operation belongs to the selected region, the process proceeds to the next step, and the hydrogenated gasoline HCCI combustion operation is executed (step 412).

  On the other hand, when it is determined in step 410 that the hydrogenated gasoline HCCI combustion operation does not belong to the selected region, the process proceeds to the next step and the mixed gasoline operation is executed (step 414).

  As described above, according to the fourth embodiment, the HCCI combustion operation can be performed in the widest possible operation region. Thereby, high efficiency and low emission can be realized in a wide range of operation.

  Incidentally, in Embodiment 4 described above, the in-cylinder hydrogenated gasoline injection valve 32 is incorporated in the engine main body 2 so that hydrogenated gasoline can be directly injected into the combustion chamber 4, but the arrangement thereof is here. It is not limited. That is, the in-cylinder hydrogenated gasoline injection valve 32 may be disposed in the intake pipe 12 so that hydrogenated gasoline is injected into the intake pipe 12 and is sucked into the combustion chamber 4 while being mixed with air.

It is a figure for demonstrating the structure of the hydrogen utilization internal combustion engine of Embodiment 1 of this invention. It is a figure which shows the map used for selection of the operating method of an internal combustion engine in Embodiment 1 of this invention. It is a flowchart of the routine performed in Embodiment 1 of the present invention. It is a flowchart of the routine performed in Embodiment 2 of this invention. It is a figure which shows the map used for selection of the operating method of an internal combustion engine in Embodiment 3 of this invention. It is a flowchart of the routine performed in Embodiment 3 of the present invention. It is a figure which shows the map used for selection of the operating method of an internal combustion engine in Embodiment 4 of this invention. It is a flowchart of the routine performed in Embodiment 4 of this invention.

Explanation of symbols

2 Engine body 4 Combustion chamber 10 Internal combustion engine (engine)
12 Intake pipe 14 Exhaust pipe 16 Throttle valve 18 Hydrogen injection valve 20 Gasoline injection valve 22 Spark plug 24 Dehydrogenation reactor 26 Heat exchanger 28 Dehydrogenation catalyst 30 Hydrogenated gasoline injection valve 32 In-cylinder hydrogenated gasoline injection valve 34 Hydrogenation Gasoline tank 36 Hydrogenated gasoline supply pipe 38 Pipe 40 Separating device 42 Gasoline pipe 44 Hydrogen pipe 48 Gasoline tank 50 Gasoline supply pipe 52 Hydrogen tank 54 Hydrogen supply pipe 70 ECU (Electrical Control Unit)
72 Speed sensor 74 Accelerator opening sensor 76 Vehicle speed sensor 78 Temperature sensor 80 Temperature sensor

Claims (3)

In a hydrogen-based internal combustion engine capable of compression self-ignition operation and spark ignition operation,
Fuel separation means for separating hydrogenated fuel containing organic hydride into hydrogen and dehydrogenated fuel;
Fuel supply means for supplying the internal combustion engine selectively or in combination with any one of the hydrogenated fuel, the hydrogen, and the dehydrogenated fuel;
Control means for performing operation by compression auto-ignition diffusion combustion using the hydrogenated fuel as fuel;
Equipped with a,
When the internal combustion engine is operating in a predetermined operating region, the control means performs an operation by compression auto-ignition diffusion combustion using the hydrogenated fuel as a fuel, and the internal combustion engine is in a lower load region than the predetermined operating region. A hydrogen-utilized internal combustion engine characterized by performing an operation by spark ignition combustion using the dehydrogenated fuel and the hydrogen as fuel . When the internal combustion engine is operated in a lower load region than the operation region where the internal combustion engine is operated using the dehydrogenated fuel and the hydrogen as fuel, the control means is based on compression auto-ignition diffusion combustion using the hydrogenated fuel as a fuel. 2. The hydrogen-utilizing internal combustion engine according to claim 1 , wherein the operation is performed. Water temperature acquisition means for acquiring the water temperature of the internal combustion engine,
When the water temperature is equal to or lower than a determination value and the internal combustion engine is operated in an operation region based on compression auto-ignition combustion, the control means applies the internal combustion engine to the internal combustion engine prior to supplying the hydrogenated fuel that is fuel. 3. The hydrogen-utilizing internal combustion engine according to claim 1, wherein the hydrogen is supplied and the ignition device disposed in the combustion chamber is operated. 4.

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