JP2007064150A - Control device for hydrogen engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for a hydrogen engine capable of using both of hydrogen and gasoline and extending cruising distance while inhibiting drop of emission performance. <P>SOLUTION: This control device for the hydrogen engine 1 is provided with hydrogen supply devices 50, 40, 42 supplying the engine with hydrogen from a hydrogen storage source 52, gasoline supply devices 64, 44 supplying the engine with gasoline from a gasoline storage source 62, and a hydrogen remaining quantity detection means 66 detecting hydrogen remaining quantity of the hydrogen storage source, and includes a supply fuel change over means changing over from supply of hydrogen by the hydrogen supply device to supply of both of hydrogen and gasoline by the hydrogen supply device and the gasoline supply device when hydrogen remaining quantity is detected as a predetermined value or less by the hydrogen remaining quantity detection means, and a supply fuel ration setting means keeping hydrogen larger than gasoline in hydrogen and gasoline supply ratio at a time of low rotation speed of the hydrogen engine and increasing ratio of gasoline than low rotation speed at a time of high speed rotation. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a control device for a hydrogen engine, and more particularly to a hydrogen supply device that supplies hydrogen to the hydrogen engine, a gasoline supply device that supplies gasoline to the hydrogen engine, and a hydrogen residue that detects the remaining amount of hydrogen in a hydrogen storage source. The present invention relates to a control device for a hydrogen engine provided with a quantity detection means.

  A dual fuel hydrogen engine that can use both hydrogen and gasoline as fuel is known (for example, Patent Document 1). In such a hydrogen engine, the vehicle is usually driven by hydrogen fuel, and when the remaining amount of hydrogen is reduced, the vehicle is switched to running by gasoline. In other words, even if the number of hydrogen stations as infrastructure is small and hydrogen cannot be replenished, the cruising range can be extended with gasoline.

  In such a dual fuel hydrogen engine, in order to extend the cruising range, it is necessary to use hydrogen and gasoline effectively. For example, it is conceivable to effectively use each fuel by mixing hydrogen and gasoline. In particular, when both the remaining hydrogen amount and the remaining gasoline amount are small, it is necessary to ensure that the vehicle can travel to the hydrogen station or the gasoline station.

  Patent Document 2 discloses an engine in which compressed natural gas is injected into an intake passage and gasoline is injected into an intake passage when the residual pressure of the compressed natural gas of fuel is reduced. In the engine described in Patent Document 2, when the residual pressure of the compressed natural gas is small and the combustion cannot be stabilized, the compressed natural gas remains and is wasted, and the cruising distance is reduced accordingly. It is intended to prevent.

Japanese Patent Application Laid-Open No. 07-097906 JP 2004-346841 A

  Here, the hydrogen engine is originally an engine excellent in terms of emission performance and fuel consumption performance. Accordingly, there is a demand for ensuring emission performance even when gasoline is used in a hydrogen engine. However, in the dual fuel hydrogen engine described above, when hydrogen and gasoline are mixed and burned, in comparison with when only hydrogen is burned, in general, the output performance is easily obtained, but the emission performance is likely to be reduced, because gasoline is mixed. There is a problem.

  Accordingly, the present invention has been made to solve the above-described problems of the prior art, and is a hydrogen engine that can use both hydrogen and gasoline that can extend the cruising distance while suppressing a decrease in emission performance. It aims to provide a control device.

In order to achieve the above object, the present invention provides a hydrogen supply device that supplies hydrogen from a hydrogen storage source to a hydrogen engine, a gasoline supply device that supplies gasoline from a gasoline storage source to a hydrogen engine, and a hydrogen residue in the hydrogen storage source. A hydrogen engine control device comprising a hydrogen remaining amount detection means for detecting the amount of hydrogen supplied by the hydrogen supply device when the hydrogen remaining amount detection means detects that the hydrogen remaining amount is equal to or less than a predetermined value. From the hydrogen supply device and the gasoline supply device to the supply fuel switching means for switching to supply of both hydrogen and gasoline, and at the time of low rotation of the hydrogen engine, the supply ratio of hydrogen to gasoline is larger than that of gasoline and high rotation Sometimes, it is characterized by having a supply fuel ratio setting means for increasing the ratio of gasoline compared to that at the time of low rotation.
In the present invention configured as described above, when the remaining amount of hydrogen is detected to be equal to or less than a predetermined value, the supply fuel switching means switches from supplying hydrogen to supplying both hydrogen and gasoline. Effective use of both hydrogen and gasoline can extend the cruising range. Furthermore, the supply fuel ratio setting means makes the supply ratio of hydrogen and gasoline larger than gasoline at low revolution, and increases the ratio of gasoline at high revolution compared to low revolution. It is possible to extend the cruising distance while suppressing a decrease in the amount of HC and CO emissions and at the same time ensuring high output at high revolutions.

In the present invention, preferably, when both hydrogen and gasoline are supplied, the hydrogen supply amount and the gasoline supply amount are determined so that the hydrogen air-fuel ratio and the gasoline air-fuel ratio are in the lean region, respectively. It has a fuel supply amount determination means.
In the present invention configured as described above, the hydrogen supply amount and the gasoline supply amount are determined so that the air fuel ratio of hydrogen and the air fuel ratio of gasoline are in the lean region, respectively. The cruising range can be extended more reliably.

In the present invention, preferably, the hydrogen engine further includes a gasoline remaining amount detecting means for detecting a gasoline remaining amount of a gasoline storage source, and the supply fuel switching means has a predetermined amount of hydrogen remaining by the hydrogen remaining amount detecting means. When it is detected that the gasoline remaining amount is less than the predetermined value by the gasoline remaining amount detecting means, the supply is switched from the supply of hydrogen to the supply of both hydrogen and gasoline.
In the present invention configured as described above, when both hydrogen and gasoline are low, the cruising distance can be extended by effectively using each of these fuels.

In the present invention, it is preferable that the hydrogen engine further includes an EGR device, and the control device further detects that the remaining amount of hydrogen is equal to or less than a predetermined value by the remaining hydrogen amount detecting means and further detects the remaining gasoline amount. When it is detected that the gasoline remaining amount exceeds a predetermined value, the second supply fuel switching means for switching from hydrogen supply to gasoline supply, and when both hydrogen and gasoline are supplied, EGR of the EGR device EGR control means for increasing the rate higher than the EGR rate at the time of gasoline supply.
In the present invention configured as described above, the EGR control means increases the EGR rate when both hydrogen and gasoline are supplied compared to the EGR rate when gasoline is supplied. It is possible to suppress the deterioration of the emission performance due to, particularly the increase of the NOx amount. Furthermore, since the ignitability of hydrogen is very high, deterioration of combustibility due to an increase in the EGR rate is also prevented.

  According to the hydrogen engine capable of using both hydrogen and gasoline according to the present invention, the cruising distance can be extended while suppressing a decrease in emission performance.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
First, the configuration of a hydrogen engine to which a hydrogen engine control device according to an embodiment of the present invention is applied will be described with reference to FIGS. 1 and 2. FIG. 1 is a diagram showing a schematic configuration of a hydrogen engine main body to which a hydrogen engine control device according to the present embodiment is applied, and FIG. 2 is a hydrogen showing a hydrogen engine main body shown in FIG. 1 and a device associated therewith. It is a figure which shows the whole structure of an engine.

  First, as shown in FIG. 1, the hydrogen engine 1 according to the present embodiment is a rotary engine. The hydrogen engine 1 includes a rotor housing 2 having a trochoidal inner peripheral surface and side housings 4 (one of which is not shown) having planar inner surfaces disposed on both sides thereof. The rotor 6 is arranged in the space constituted by 4. The rotor 6 is supported by the inner eccentric shaft 8 and rotates eccentrically with the eccentric shaft 8. Around the rotor 6, three working chambers 10, 11 and 12 surrounded by the housings 2 and 4 and the rotor 6 are formed. The volume of each working chamber 10, 11, 12 is changed by the eccentric rotation of the rotor 6. Then, the rotor 6 is rotated and the eccentric shaft 8 is rotated by a series of steps of intake, compression, expansion (explosion), and exhaust in the working chambers 10, 11, and 12, and the rotational force is used as power to drive the eccentric shaft 8 as a power. Is output to a drive shaft (not shown). In the state shown in FIG. 1, intake and compression strokes are performed in the working chamber 10, an expansion (explosion) process is performed in the working chamber 11, and an exhaust stroke is performed in the working chamber 12.

  An ignition plug 14 is attached to the rotor housing 2, and an intake port 16 and an exhaust port 18 are formed in the side housing 4. An intake passage 20 is connected to the intake port 16, and air is guided into the working chamber 10 through the intake passage 20. Further, an exhaust passage 22 is connected to the exhaust port 18, and the exhaust gas in the working chamber 12 is exhausted through the exhaust passage 22.

As shown in FIG. 2, a throttle valve 24 is provided on the upstream side of the intake passage 20, and an air cleaner 26 is further provided on the upstream side thereof.
Further, an exhaust gas purification catalyst (not shown) or the like is provided on the downstream side of the exhaust passage 22. The exhaust passage 22 is provided with an EGR device 30 for returning a part of the exhaust gas in the exhaust passage 22 to the intake passage 20. The EGR device 30 controls the EGR rate, the EGR passage 32 that connects the exhaust passage 22 and the intake passage 20, the EGR cooler 34 that cools the exhaust gas that recirculates in the EGR passage 32 to increase the density, and the EGR rate. EGR valve 36. The EGR valve 36 is connected to a control unit (ECU) 70, and the EGR rate is controlled by the ECU 70 as described later.

  Here, the hydrogen engine 1 can use both hydrogen (hydrogen gas) and gasoline as fuel. As shown in FIG. 1, as a hydrogen and fuel injection device, a direct injection hydrogen gas injector 40 that injects hydrogen into the working chamber 10 is attached to the rotor housing 2, and a port injection type that injects hydrogen into the intake passage 20. A hydrogen gas injector 42 is attached to the intake passage 20, and a port injection type gasoline injector 44 that injects gasoline fuel into the intake passage 20 is closer to the intake port 16 than the port injection type hydrogen gas injector 26. Is attached.

  As shown in FIG. 2, each hydrogen gas injector 40, 42 is connected to a hydrogen high-pressure gas tank 52 via a hydrogen gas supply passage 50 branched in the middle, and hydrogen gas is supplied from this hydrogen high-pressure gas tank 52. It is like that. A stop valve 54 for controlling discharge of hydrogen gas from the tank 52 to the hydrogen gas supply passage 50 is provided at the discharge port of the hydrogen high-pressure gas tank 52, and further, the hydrogen gas supply passage 50 on the downstream side thereof is provided with a stop valve 54. A shutoff valve 56 for controlling the hydrogen supply amount (hydrogen supply pressure) to each of the injectors 40 and 42 is provided. Further, a hydrogen gas pressure sensor 58 for detecting the residual pressure in the hydrogen gas supply passage 50 is attached to the hydrogen gas supply passage 50 on the downstream side of the shutoff valve 56. The remaining amount of hydrogen in the hydrogen high-pressure gas tank 52 is calculated from the remaining pressure in the hydrogen gas supply passage 50 detected by the sensor 58.

The gasoline injector 44 is connected to a gasoline tank 62 via a gasoline supply passage 60. The gasoline in the gasoline tank 62 is sent to the gasoline supply passage 60 by the fuel pump 64. A gasoline level sensor 66 for detecting the remaining amount of gasoline is attached to the gasoline tank 62.
Each of the hydrogen and gasoline injectors 40, 42, 44 incorporates a solenoid valve (not shown), and the hydrogen gas injection amount by the hydrogen gas injectors 40, 42 and the gasoline by the gasoline injector 44. The injection amount is adjusted by the opening / closing amount of each electromagnetic valve. Each injector 40, 42, 44 is connected to the ECU 70, and the ECU 70 controls the hydrogen gas ejection amount and the gasoline ejection amount as will be described later.

  In addition to the hydrogen gas pressure sensor 58 and the gasoline level sensor 66 described above, an engine speed sensor 72 that detects the engine speed is attached to the engine body. An oxygen concentration sensor 74 that detects the oxygen concentration in the exhaust passage 22 is attached to the exhaust passage 22, and the air-fuel ratio λ is calculated based on the oxygen concentration detected by the oxygen concentration sensor 74. Further, although not shown, a water temperature sensor for detecting the temperature of the engine cooling water, an intake air temperature sensor for detecting the temperature and amount of air in the intake passage 20, an air flow sensor, and a throttle opening sensor for detecting the opening of the throttle valve 24 An exhaust temperature sensor for detecting the temperature of the exhaust gas in the exhaust passage 22, a hydrogen gas flow meter for detecting the flow rate of the hydrogen gas flowing in the hydrogen gas supply passage 50, and a flow rate of the gasoline flowing in the gasoline supply passage 60. A gasoline flow meter and the like are also provided in the engine 1.

  The ECU 70 outputs an output signal from these sensors, in particular, an output signal from the hydrogen gas pressure sensor 58 relating to the remaining amount H of hydrogen in the hydrogen high-pressure gas tank 52, an output signal relating to the remaining amount G of gasoline from the gasoline level sensor 66, and engine rotation. An output signal related to the engine speed N from the number sensor 72 and an output signal related to the air-fuel ratio λ from the oxygen concentration sensor 74 are inputted.

Next, the contents of the fuel injection control and the EGR rate control performed by the ECU 70 will be described with reference to FIGS.
FIG. 3 is a flowchart showing the contents of fuel injection control by the control unit of the present embodiment, and FIG. 4 is a chart showing a control map for determining the mixing ratio of hydrogen and gasoline based on the engine speed. . In the flowchart shown in FIG. 3, “S” indicates each step.

First, as shown in FIG. 3, in S <b> 1, an output signal related to the remaining amount of hydrogen H, an output signal indicating the remaining amount of gasoline G, and an output signal indicating the engine speed N are read from the sensors 58, 66, and 72.
Next, in S2, it is determined whether or not the remaining hydrogen amount H read in S1 is equal to or less than a predetermined value. In the present embodiment, the predetermined value is set to 3% of the total capacity of the hydrogen high-pressure gas tank 52. For example, if the total capacity of the tank 52 is 35 MPa, the predetermined value is set to 1 MPa. Thus, in S2, it is determined whether or not the remaining hydrogen amount H is small.
In S3, it is determined whether or not the gasoline remaining amount G read in S1 is equal to or less than a predetermined value. In the present embodiment, the predetermined value is set to 3% of the total capacity of the gasoline tank 62. Thus, in S3, it is determined whether the gasoline remaining amount G is small. Note that the predetermined values of the remaining amount of hydrogen and the remaining amount of gasoline may differ depending on the vehicle.

In the present embodiment, the operation using hydrogen, the operation using gasoline, and the operation in which hydrogen and gasoline are mixed are switched according to the determinations of S2 and S3. Each case will be described below.
First, a case where it is determined in S2 that the remaining hydrogen amount H exceeds a predetermined value, that is, a case where there is a surplus in the remaining hydrogen amount will be described.
In this case, after completion of the determination in S2, the process proceeds to S4, and operation with hydrogen gas is performed. Specifically, the ECU 70 prohibits the injection of gasoline by the port injection type gasoline injector 44 and causes each injector 40 to execute the injection of hydrogen gas by the direct injection type hydrogen gas injector 40 or the port injection type hydrogen gas injector 42. , 42 and 44 are controlled.

Here, the control content of the hydrogen gas injection in S4 will be described. In the present embodiment, the injectors 40 and 42 are used properly according to the engine speed.
Specifically, when the engine speed N read in S1 is in the first region (800 to 2500 rpm), hydrogen gas is injected only by the direct injection hydrogen gas injector 40 in the compression stroke. Thereby, the charging efficiency of air and hydrogen gas is improved, and output torque is ensured. That is, if it is injected from the intake passage 20 during the intake stroke, it is difficult to ensure a sufficient amount of air in the working chamber 10 due to the large volume of hydrogen gas.

When the engine speed N is in the second region (2500 to 5000 rpm), hydrogen gas is injected only by the direct injection hydrogen gas injector 40 in the intake stroke. Thus, by injecting hydrogen gas at the stage of the intake stroke, the mixing time of air and hydrogen gas is ensured, and the occurrence of abnormal combustion such as premature ignition due to insufficient mixing is suppressed.
When the engine speed N is in the third region (5000 to 7000 rpm), the injection by the direct injection hydrogen gas injector 40 in the compression stroke and the premixed injection by the port injection hydrogen gas injector 42 in the intake stroke are used in combination. This is because the torque is ensured by the injection by the direct injection hydrogen gas injector 40 in the compression stroke, and the mixing property of air and hydrogen gas is improved by the premixed injection by the port injection hydrogen gas injector 42. In this embodiment, the ratio of the injection amounts of the injectors 40 and 42 is set such that the injection amount by the direct injection hydrogen gas injector 40 is 20% and the injection amount by the port injection hydrogen gas injector 42 is 80%.

The hydrogen gas injection amount itself is determined based on the intake air amount, the intake air temperature, the output signal from the oxygen concentration sensor 74 (air-fuel ratio λ), etc., so that the air-fuel ratio becomes λ = 2.
When the process in S4 ends, the process proceeds to S5, where the ECU 70 controls the EGR valve 36 so that the EGR rate becomes 50%. As described above, the EGR rate is set to a large value of 50% as compared with the EGR rate (limit is about 20%) when only gasoline is burned to effectively reduce NOx. Here, even if the EGR rate is set to a large value of 50%, since hydrogen gas is very excellent in ignitability compared to gasoline, there is very little concern about deterioration in combustibility.

Next, if it is determined in S2 that the remaining amount of hydrogen H is less than or equal to the predetermined value and it is determined in S3 that the remaining amount of gasoline G exceeds the predetermined value, that is, the remaining amount of hydrogen is small but the remaining amount of gasoline. A case where there is a margin in the amount will be described.
In this case, after completion of the determination in S3, the process proceeds to S6, and driving with gasoline is performed. Specifically, the ECU 70 causes the port injection type gasoline injector 44 to execute gasoline injection, and prohibits the injection of hydrogen gas from the direct injection type hydrogen gas injector 40 and the port injection type hydrogen gas injector 42. , 42 and 44 are controlled. The injection amount of gasoline hydrogen gas is determined based on the intake air amount, the intake air temperature, the output signal from the oxygen concentration sensor 74 (air-fuel ratio λ), and the like so that the air-fuel ratio becomes λ = 1.
Next, in S7, the ECU 70 controls the EGR valve 36 so that the EGR rate becomes 20%. The value of 20% of the EGR rate is generally a value close to the limit value in gasoline combustion. If the EGR rate exceeds 20%, it is very difficult to ignite, or there is a risk of misfire even if ignited.

Next, when it is determined in S2 that the remaining amount of hydrogen H is less than or equal to a predetermined value and it is determined in S3 that the remaining amount of gasoline G is less than or equal to a predetermined value, that is, both the remaining amount of hydrogen and the remaining amount of gasoline are small. The case will be described.
In this case, after completion of the determination in S3, the process proceeds to S8, and an operation in which hydrogen gas and gasoline are mixed is performed. Specifically, the ECU 70 performs injection of gasoline by the port injection type gasoline injector 44 and injection of hydrogen gas by the direct injection type hydrogen gas injector 40 or the port injection type hydrogen gas injector 42, 42 and 44 are controlled.

Here, the contents of control of hydrogen gas and gasoline injection in S8 will be described. In this embodiment, the mixing ratio of hydrogen gas and gasoline is set according to the engine speed.
In this S8, based on the map shown in FIG. 4, the mixing ratio of hydrogen gas and gasoline according to the engine speed N is determined, and each injector 40, 42, 44 is controlled so as to be the determined mixing ratio. Like to do.
In the present embodiment, as shown in FIG. 4, in the engine speed (up to 3000 rpm) in the practical range (low rotation range), the hydrogen gas and the ratio of gasoline are set so that the hydrogen gas is larger than the gasoline. 70% and gasoline 30%. At the engine speed in the middle speed range (3,000 to 3500 rpm), hydrogen gas is set to decrease linearly from 70% to 50% with respect to the engine speed N, and gasoline is set to engine speed from 50% to 70%. It is set so as to increase linearly with respect to N. At the engine speed in the high speed range (from 3500 rpm), the ratio of hydrogen gas to gasoline is set to be equal to 50%. Therefore, in this high speed range, the ratio of hydrogen gas is lowered while the ratio of gasoline is increased compared to the practical range.

  In the present embodiment, in this way, in the practical range, by controlling so that the ratio of hydrogen gas is larger than the ratio of gasoline, the increase in emissions due to the combined use of gasoline is minimized. That is, the generation of HC and CO can be suppressed as much as possible because of the small proportion of gasoline. On the other hand, in the high rotation range, a high output (high torque) can be obtained by increasing the ratio of gasoline compared to the practical range. In addition, by obtaining a high torque, it is possible to prevent the accelerator from being depressed excessively in a situation where a torque is necessary, such as a slope, and to extend the cruising distance.

  Here, the injectors 40 and 42 for injecting the hydrogen gas are selectively used according to the engine speed as in S4 described above. That is, in the first region (800 to 2500 rpm), only the direct injection hydrogen gas injector 40 is used in the compression stroke, and in the second region (2500 to 5000 rpm), only the direct injection hydrogen gas injector 40 is used in the intake stroke. 7000 rpm), hydrogen gas is injected by the combined use of the direct injection type hydrogen gas injector 40 in the direct injection compression stroke and the premixed injection by the port injection type hydrogen gas injector 42 in the intake stroke.

  The injection amounts of hydrogen gas and gasoline are set so that the air-fuel ratio of hydrogen gas and the air-fuel ratio of gasoline are in a lean region, respectively. For example, the air-fuel ratio of hydrogen gas and the air-fuel ratio of gasoline are each set to λ = 2. The air-fuel ratio of hydrogen gas and gasoline as a whole is set to be λ = 1. The injection amount itself is determined based on the intake air amount, the intake air temperature, the output signal (air-fuel ratio λ) from the oxygen concentration sensor 74, and the like.

  When the process in S8 ends, the process proceeds to S9, where the ECU 70 controls the EGR valve 36 so that the EGR rate becomes 40%. In this way, NOx is effectively reduced by setting the EGR rate to a large value of 40% compared to the EGR rate (for example, 20%) when only gasoline is burned. That is, since the ignitability of hydrogen gas is high, the EGR rate can be increased as compared to the case of gasoline alone, and as a result, deterioration of combustibility can be prevented and NOx can be reduced.

Here, FIG. 5 shows output characteristics and charging efficiency characteristics as an example of engine characteristics when hydrogen, a mixture of hydrogen and gasoline, and gasoline are respectively used.
As shown in FIG. 5, when each fuel is used, the charging efficiency and the torque as the output change according to the engine speed. When hydrogen and gasoline are mixed, the characteristics change according to the mixing ratio, and in the practical range of 70% hydrogen and 30% gasoline, the charging efficiency and output when using hydrogen are almost the same. As the ratio is decreased and the gasoline ratio is increased, both the charging efficiency and the output increase, and in the high speed range (50% hydrogen, 50% gasoline), the magnitude is approximately halfway between using hydrogen and gasoline. Filling efficiency and output are obtained. As described above, it has been confirmed that even when an operation in which hydrogen and gasoline are mixed is performed when both the remaining amount of hydrogen is small, both the charging efficiency and the output are ensured and the vehicle can travel reliably.

  As another embodiment, when it is determined in S2 that the remaining amount of hydrogen H is equal to or less than a predetermined value, the operation by mixing hydrogen gas and gasoline in S8 and S9 is performed regardless of the remaining amount of gasoline. May be. In this case, in S3, it is determined whether or not the remaining amount of hydrogen H is 0. When it is determined that the remaining amount of hydrogen is 0, that is, when all the hydrogen is used up, the operation is switched to the gasoline only operation in S6 and S7. It is good to do so. According to this modification, it is possible to perform an operation for reducing emissions, for example, HC, CO, and NOx, as compared with an operation using only gasoline until the hydrogen gas is used up.

  In the present embodiment, the control device for the hydrogen engine is applied to the rotary engine, but can also be applied to a reciprocating engine.

It is a figure which shows schematic structure of the hydrogen engine main-body part by embodiment of this invention. It is a figure which shows the whole structure of the hydrogen engine by this embodiment which shows the hydrogen engine main-body part shown in FIG. 1, and its accompanying apparatus. It is a flowchart which shows the control content by the control unit of this embodiment. It is a graph which shows the control map for determining the mixing ratio of hydrogen and gasoline based on an engine speed. It is a diagram which shows the relationship between the engine speed at the time of mixing of hydrogen and gasoline, and charging efficiency or an output with the relationship at the time of hydrogen use and gasoline use.

Explanation of symbols

1 Hydrogen Engine 20 Intake Passage 22 Exhaust Passage 32 EGR Passage 36 EGR Valve 40 Direct Injection Hydrogen Gas Injector 42 Port Injection Hydrogen Gas Injector 44 Port Injection Gasoline Injector 50 Hydrogen Gas Supply Passage 52 Hydrogen High Pressure Gas Tank 58 Hydrogen Gas Pressure Sensor 60 Gasoline Supply passage 62 Gasoline tank 66 Gasoline level sensor 70 Control unit 72 Engine speed sensor

Claims (4)

A hydrogen supply device for supplying hydrogen from a hydrogen storage source to a hydrogen engine, a gasoline supply device for supplying gasoline from a gasoline storage source to a hydrogen engine, and a hydrogen remaining amount detecting means for detecting a hydrogen remaining amount of the hydrogen storage source. A hydrogen engine control device comprising:
When the remaining hydrogen amount detecting means detects that the remaining hydrogen amount is less than or equal to a predetermined value, the supply of hydrogen from the hydrogen supply device to the supply of both hydrogen and gasoline by the hydrogen supply device and the gasoline supply device. Supply fuel switching means for switching to,
And a supply fuel ratio setting means for making the supply ratio of hydrogen and gasoline larger than that of gasoline when the hydrogen engine is running at a low speed and increasing the ratio of gasoline when running at a high speed than when running at a low speed. Control device for hydrogen engine.   The fuel supply amount determination means further determines a hydrogen supply amount and a gasoline supply amount so that the hydrogen air-fuel ratio and the gasoline air-fuel ratio are in a lean region when both hydrogen and gasoline are supplied. 2. A control device for a hydrogen engine according to 1. The hydrogen engine further includes a gasoline remaining amount detecting means for detecting a gasoline remaining amount of the gasoline storage source,
The supply fuel switching means is configured to detect hydrogen when the remaining amount of hydrogen is detected to be less than a predetermined value by the remaining amount of hydrogen detection means and when the remaining amount of gasoline is detected to be less than a predetermined value by the remaining amount of gasoline detection means. The hydrogen engine control means according to claim 1 or 2, wherein the supply is switched from the supply of hydrogen to the supply of both hydrogen and gasoline. The hydrogen engine further includes an EGR device,
The control device further detects the amount of hydrogen when the hydrogen remaining amount detecting means detects that the remaining amount of hydrogen is less than a predetermined value and the gasoline remaining amount detecting means detects that the gasoline remaining amount exceeds a predetermined value. Second supply fuel switching means for switching from supply to gasoline supply;
The hydrogen engine control device according to claim 3, further comprising: an EGR control unit that increases an EGR rate of the EGR device when an amount of both hydrogen and gasoline is supplied, compared to an EGR rate at the time of gasoline supply.

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