JP4438715B2 - Hydrogen engine fuel control system - Google Patents

Description

  The present invention relates to a fuel control device for a hydrogen engine comprising a direct injection injector that directly injects gaseous hydrogen into a working chamber and a premixing injector that injects gaseous hydrogen into an intake passage communicating with the working chamber. .

  2. Description of the Related Art Conventionally, for example, in an automatic transmission (AT) vehicle, it is known to forcibly reduce the torque by temporarily retarding the ignition timing of the engine in order to suppress a shift shock at the time of shifting.

In relation to this, for example, in Patent Document 1, in a gasoline engine, it is intended to reduce the shift shock without causing an increase in the exhaust temperature, and the fuel is reduced when the shift shock is reduced by retarding the ignition timing. Discloses a shift shock reduction device that corrects the increase in accordance with the retard amount of the ignition timing.
Japanese Patent Publication No. 6-63479

  By the way, in recent years, for the purpose of reducing pollution, development of a vehicle equipped with an engine that uses gaseous fuel such as compressed natural gas, liquefied petroleum gas, and compressed hydrogen has been developed, but compressed hydrogen is used as the gaseous fuel. In a hydrogen engine, if the ignition timing is greatly retarded at high load, combustion becomes too slow and the exhaust gas temperature rises, and the hot exhaust gas is brought into the next intake stroke, so that the next cycle Therefore, there is a possibility that an abnormal combustion that ignites prematurely occurs and a backfire to the intake system (so-called backfire) occurs.

  Further, as a method for reducing the torque, it is also known to suppress the air filling amount in addition to the retard of the ignition timing. However, in this method, the air filling amount is suppressed in response to a predetermined torque reduction request. If the throttle opening is reduced, the response to the torque down request may be delayed due to the time during which the air flow closed by the throttle valve flows through the intake passage to the working chamber.

  The present invention has been made in view of the above technical problem, and an object of the present invention is to provide a fuel control device for a hydrogen engine that can reduce the torque with good responsiveness while suppressing the occurrence of backfire.

  For this reason, the invention according to claim 1 of the present application provides a first hydrogen supply means for directly injecting and supplying gaseous hydrogen into the working chamber, and a second apparatus for injecting and supplying gaseous hydrogen into the intake passage communicating with the working chamber. A hydrogen engine fuel control apparatus comprising: a hydrogen supply means; a determination means for determining whether or not a predetermined torque-down control condition is satisfied; and the first according to an operating state of the hydrogen engine. The hydrogen supply ratio of hydrogen supplied from the hydrogen supply means and the second hydrogen supply means is set, and when it is determined by the determination means that a predetermined torque-down control condition is satisfied, Hydrogen supply ratio control means for controlling the hydrogen supply ratio so as to increase the supply ratio of hydrogen supplied from the second hydrogen supply means with respect to the supply ratio. .

  In the invention according to claim 2 of the present application, in the invention according to claim 1, the hydrogen supply rate control means is a hydrogen hydrogen supplied from the first hydrogen supply means and the second hydrogen supply means. The supply ratio is set so as to increase the supply ratio of hydrogen supplied from the second hydrogen supply means in accordance with an increase in the engine speed.

  Furthermore, in the invention according to claim 3 of the present application, in the invention according to claim 1 or 2, when the hydrogen supply ratio control means determines that a predetermined torque-down control condition is satisfied by the determination means, When the engine speed is equal to or higher than a predetermined speed and the engine load is in a high speed and full load range operation state, the hydrogen is supplied only from the second hydrogen supply means. When the supply ratio is controlled and the hydrogen supply amount from the second hydrogen supply means is controlled so that the air / fuel ratio is leaner than the stoichiometric air / fuel ratio, and the engine is in an operating state other than the high rotation and full load range. Is characterized in that the hydrogen supply rate is controlled so as to increase the supply rate of hydrogen supplied from the second hydrogen supply means.

As described above, as a means for executing torque reduction, in addition to a method of changing the ignition timing, a method of suppressing the air filling amount is known. Normally, the throttle valve opening is closed in order to suppress the amount of air filling, but in this case, a response delay occurs due to the volume of the intake system from the throttle valve to the working chamber, so the torque down responsiveness is reduced. bad. On the other hand, when gaseous hydrogen is injected and supplied, the volume of gaseous hydrogen is larger than that of liquid fuel such as gasoline, so if the injection is performed during the intake stroke, the volumetric air of gaseous hydrogen will not enter the working chamber. , Air filling amount is reduced. That is, according to the method in which gaseous hydrogen is injected and supplied during the intake stroke, the amount of air filling can be reduced with good responsiveness because there is no influence of the volume of the intake system as described above.
Therefore, according to claim 1 of the present application, it is necessary to retard the ignition timing because the torque is reduced by increasing the supply rate of gaseous hydrogen by the second hydrogen supply means and suppressing the amount of air filling. In addition, torque can be reduced with good responsiveness while suppressing the occurrence of backfire.

Another cause of backfire is low mixing of air and gaseous hydrogen. The higher the engine speed, the shorter the time required for the intake stroke of the engine, and the shorter the mixing time of air and gaseous hydrogen, the more the mixing property tends to deteriorate. If the miscibility of air and gaseous hydrogen is poor, dense gaseous hydrogen lumps are unevenly distributed in a part of the working chamber and premature ignition occurs from there. Fire can be suppressed.
According to claim 2 of the present application, since the hydrogen supply rate by the second hydrogen supply means is set to increase in accordance with the increase in the engine speed, the mixing property of air and gaseous hydrogen can be improved. This can suppress the occurrence of premature ignition.

Further, in the operating state in the high rotation and full load range, although the amount of gaseous hydrogen is large, the rotation speed is high and the mixing time of air and gaseous hydrogen is short. Even if the ratio is increased, there is a limit to improving the mixing property. Further, the hydrogen engine has an emission characteristic that the NOx emission amount decreases when the air-fuel ratio is set to be leaner than the stoichiometric air-fuel ratio, and the NOx emission amount becomes substantially 0 near λ = 2.
Therefore, according to claim 3 of the present application, at the time of a torque reduction request, in the operating state of the high rotation and full load region, hydrogen is supplied only from the second hydrogen supply means, and the air-fuel ratio is substantially reduced. By setting the lean value close to 0, premature ignition can be suppressed by making the air-fuel ratio lean while suppressing the deterioration of the NOx emission amount.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is an explanatory diagram schematically showing a rotary type hydrogen engine according to an embodiment of the present invention.
The hydrogen engine 1 has a rotor housing H ₁ having a trochoidal inner peripheral surface and a substantially flat side housing H ₂ that extends along the plane direction of the rotor R as an outer configuration. . In a state where the housings H ₁ and H ₂ are combined and the rotor R is housed in an internal space formed inside the housings H ₁ and H ₂ , the inner surface of the rotor housing H ₁ , the side housing H ₂ , Thus, three working chambers E are defined. Each working chamber E repeatedly expands and contracts its working volume as the rotor R rotates about the eccentric axis C, and during each rotation of the rotor R, each working chamber E has an intake stroke, a compression stroke, and an expansion stroke. A series of strokes consisting of a stroke and an exhaust stroke is performed.

The rotor housing H ₁ includes a hydrogen injector (hereinafter referred to as a direct injection injector) I ₁ that directly injects gaseous hydrogen into the working chamber E in the compression stroke, and gaseous hydrogen and air supplied into the working chamber E. And an ignition plug 2 for igniting the air-fuel mixture. On the other hand, the side housing H ₂ is formed with an intake port 4 communicating with the intake passage 3 and an exhaust port 6 communicating with the exhaust passage 5.

In this embodiment, in addition to the direct injection injector I ₁ provided in the rotor housing H ₁ , a hydrogen injector (hereinafter referred to as a pre-injection) for injecting gaseous hydrogen into the intake passage 3 communicating with the working chamber E according to the intake stroke. that mixed injector) I ₂ is provided. The hydrogen engine 1 is controlled so that the hydrogen supply ratio of hydrogen supplied from the direct injection injector I ₁ and the premixing injector I ₂ is set according to the operating state.

FIG. 2 is an explanatory diagram conceptually showing the hydrogen engine 1 and the configuration related thereto. As can be seen from this figure, the direct injection injector I ₁ and the premixing injector I ₂ are provided with solenoid valves V ₁ and V ₂ , respectively, and these fuel injections are performed by opening and closing the respective solenoid valves V ₁ and V ₂ . It is controlled based on. In FIG. 2, the electromagnetic valves V ₁ and V ₂ are separately provided for the injectors I _{1 and} I ₂ , but actually, the electromagnetic valves V ₁ and V ₂ are provided for the injectors I _{1 and} I ₂ . _1, built into I ₂ .

  As shown in FIG. 2, in the present embodiment, with respect to the main body of the hydrogen engine 1, a water temperature sensor 10 for detecting the engine temperature of the hydrogen engine 1 and an engine speed sensor 11 for detecting the engine speed. And are provided. The intake passage 3 is provided with an air amount sensor 12 for detecting the amount of intake air, and a throttle valve 14 having a function of being controlled to open and close by an actuator 13 according to the amount of depression of an accelerator pedal (not shown). The exhaust passage 5 is provided with an oxygen concentration sensor 15 for detecting the oxygen concentration in order to calculate the air-fuel ratio in the working chamber.

Further, the direct injection injector I ₁ provided in the rotor housing H ₁ constituting the main body of the hydrogen engine 1 and the premixing injector I ₂ attached to the intake passage 3 are used as fuel for the injectors I _{1 and} I ₂ . It is connected to a hydrogen storage tank 21 for storing hydrogen via a hydrogen supply passage 20 for supplying hydrogen. A discharge valve of the hydrogen storage tank 21 is provided with a stop valve 22 that is controlled to be opened and closed in order to control hydrogen discharge from the hydrogen storage tank 21 to the hydrogen supply passage 20. In the hydrogen supply passage 20, a shutoff valve 23 is provided for controlling hydrogen supply to the injectors I _{1 and} I ₂ . Further, a pressure sensor 24 for detecting the hydrogen pressure in the hydrogen supply passage 20 is provided in the hydrogen supply passage 20 between the shut-off valve 23 and the direct injection injector I ₁ .

Although not particularly illustrated, the configuration related to the hydrogen engine 1 includes an air cleaner provided in the intake passage 3, a throttle opening sensor for detecting the opening of the throttle valve 14, and an exhaust gas provided in the exhaust passage 5. Other components such as a purification catalyst, an exhaust temperature sensor, and a fuel flow meter provided in the hydrogen supply passage 20 for detecting the flow rate of fuel supplied to the injectors I _{1 and} I ₂ are provided.

Furthermore, as shown in FIG. 2, an engine control unit 30 is provided for controlling the hydrogen engine 1 and related components. The engine control unit 30 is a comprehensive control device for the hydrogen engine 1, and is detected by the intake air amount detected by the air amount sensor 12, the throttle opening detected by the throttle opening sensor, and the water temperature sensor 10. Various control information such as the engine temperature, the engine speed detected by the engine speed sensor 11, the exhaust temperature detected by the exhaust temperature sensor, and the fuel flow rate to the injectors I _{1 and} I ₂ detected by the fuel flow meter Based on this, various controls such as fuel injection control and ignition timing adjustment control of the hydrogen engine 1 are performed.

The engine control unit 30 is also connected to an automatic transmission control unit 40 that performs shift control according to the operation of the shift lever by the driver, and a traction control unit 50 that controls idling of the drive wheels that are likely to occur at the time of start and acceleration. Yes. The automatic transmission control unit 40 requests the engine control unit 30 to perform torque-down control of the hydrogen engine 1 in order to reduce a shift shock at the time of shifting of the AT vehicle, while the traction control unit 50 In order to suppress slipping of the drive wheels during acceleration, the engine control unit 30 is requested to perform torque down control of the hydrogen engine 1.
The engine control unit 30, the automatic transmission control unit 40, and the traction control unit 50 each have a microcomputer as a main part.

In the configuration shown in FIG. 2, the engine control unit 30 controls the hydrogen supplied to the working chamber E and the intake passage 3 from the direct injection injector I ₁ and the premixing injector I ₂ , respectively, according to the operating state of the hydrogen engine 1. Set the ratio (hereinafter referred to as hydrogen supply ratio). FIG. 3 is a diagram showing a map used for control of hydrogen injection of the direct injection injector I ₁ and the premixing injector I _{2 according to} the present embodiment. In FIG. 3, the hydrogen injection setting of the direct injection injector I ₁ and the premixed injector I ₂ controlled according to the operating state of the hydrogen engine 1, that is, the engine speed and the engine load, takes the engine speed on the horizontal axis, The engine load is shown on the vertical axis.

As shown in FIG. 3, in this embodiment, the engine speed is less than 3000 rpm, that is, the idling speed region A1 during idling when the engine speed is less than 1000 rpm and the engine speed is 1000 rpm or more and less than 3000 rpm. it is when in the operating condition is a low rotation speed region A2, the hydrogen is supplied to the working chamber E by only the direct injector I _1.

On the other hand, when the engine speed is 3000 rpm or more, hydrogen is supplied from both the premixed injector I ₂ and the direct injection injector I ₁ . In FIG. 3, the hydrogen supply ratio of hydrogen supplied from the premixing injector I ₂ and the direct injection injector I ₁ according to the engine speed and the engine load is displayed as “premixing injector: direct injection injector”. Yes.

As shown in FIG. 3, the hydrogen supply ratio is as follows: in an operation state where the engine speed is 3000 rpm or more, the light / medium load region A3, the high load regions A4 and A5, and the full load region according to the engine load. Different settings are made for A6 to A8, and different settings are made depending on the predetermined engine speed.
When the engine load is in the engine speed is 3000rpm or more is in a light-load region A3 is a hydrogen supply rate of hydrogen supplied from the premixed injector I ₂ and direct injector I ₁ Metropolitan "5: 5 ' is set to, the hydrogen supply amount is set according to the engine speed and the engine load, is set to supply to the injection by the same amount from the premixed injector I ₂ and direct injector I ₁ Tokyo.

When the engine load is in the high load range, the hydrogen supply ratio is such that the engine rotation speed is a medium rotation and high load area A4 that is a medium rotation area of 3000 rpm or more and less than 5500 rpm, and the engine rotation speed is 5500 rpm or more. high rotational and different settings and high load region A5 is made is the region, the hydrogen feed rate of hydrogen supplied from the middle speed and high load region A4 in premixed injector I ₂ and direct injector I ₁ Metropolitan "6: 4 ", and in the high rotation and high load region A5, the hydrogen supply ratio is set to" 7: 3 ".

Further, the hydrogen supply ratio is such that when the engine load is in the full load range, the engine rotation speed is at a medium rotation and full load area A6 that is a medium rotation area of 3000 rpm or more and less than 5500 rpm, and the engine rotation speed is 5500 rpm or more. Different settings are made for the high rotation and full load regions A7 and A8, which are high rotation regions. The high rotation and full load region further includes a region A7 in which the engine speed is 5500 rpm or more and less than 6500 rpm, and an engine speed is 6500 rpm or more. The setting differs between the area A8.
Each region A6, A7, A8 are set also hydrogen feed rate of the premixed injector I ₂ and direct injector I _1, respectively for, as shown in FIG. 3, middle speed and the full load region A6 above The hydrogen supply ratio is set to “7: 3”, “8: 2” in the high rotation and full load region A7, and “8.5: 1.5” in the high rotation and full load region A8.

As described above, the engine control unit 30 premixes the hydrogen supply ratio of the hydrogen supplied from the direct injection injector I ₁ and the premixing injector I ₂ according to the increase in the engine speed if the engine load is the same. The hydrogen supply rate from the injector I ₂ is set to be increased. If the engine speed is the same, the hydrogen supply rate from the premixing injector I ₂ is set to increase with an increase in engine load. .

As described above, since the hydrogen supply rate by the premixing injector I ₂ is set to increase as the engine speed increases, the mixing of air and gaseous hydrogen can be improved, and pre-ignition can be prevented. Generation can be suppressed.

In the present embodiment, the engine control unit 30 determines whether a predetermined torque down control condition is satisfied in response to a torque down request from the automatic transmission control unit 40 or the traction control unit 50, and the like. When the torque-down control condition is satisfied, the supply of hydrogen from the premixing injector I _{2 with} respect to the hydrogen supply ratio of hydrogen supplied from the premixing injector I ₂ and the direct injection injector I ₁ shown in FIG. The hydrogen supply rate is controlled to increase the rate.

FIG. 4 is a control flowchart of the direct injection injector I ₁ and the premixing injector I _{2 according to} the present embodiment.
In the engine control unit 30 of the hydrogen engine 1, first, for example, the detection is performed by the configuration related to the hydrogen engine 1 shown in FIG. # 1).

Next, in step # 2, the hydrogen injection amount supplied to the working chamber is set according to the engine speed and the engine load based on the signal. Then, at step # 3, the fuel injection ratio of premixing hydrogen injector I ₂ and direct injector I ₁ for supplying the hydrogen injection quantity is set. That is, the above-described hydrogen supply ratio is set according to the engine speed and the engine load.
The hydrogen injection quantity is supplied from the direct injector I ₁ when the engine speed is less than 3000rpm, when the engine speed is more than 3000rpm, in response to the engine speed and the engine load as shown in FIG. 3 The hydrogen is supplied from the direct injection injector I ₁ and the premixing injector I ₂ at the hydrogen supply rate set in the above.

  When the hydrogen injection amount supplied to the working chamber and the injection ratio of premixing and direct injection are set in steps # 2 and # 3, it is determined in step # 4 whether or not a predetermined torque-down condition is satisfied. Is done. In the present embodiment, the engine control unit 30 determines whether or not a predetermined torque down control condition is satisfied in response to a torque down request from the automatic transmission control unit 40.

  If the determination result in step # 4 is no (NO), that is, if it is determined that the torque-down condition is not satisfied, hydrogen injection is executed based on the injection ratio set in step # 3. (Step # 5).

On the other hand, if the determination result in step # 4 is YES (YES), that is, if it is determined that the torque-down condition is satisfied, the engine speed Ne is a predetermined speed, which is less than 5500 rpm in this embodiment. It is determined whether or not there is (step # 6). If the determination in step # 6 is YES, i.e., when the engine speed Ne is less than 5500rpm in step # 7, the increase in the fuel injection ratio of premixed, that is, of hydrogen from premixed injector _{I 2} the feed rate is increased, the hydrogen injection is executed by premixing injector I ₂ and direct injector I ₁ this increased fuel injection ratio (step # 8).

If the determination result in step # 6 is NO, that is, if the engine speed Ne is 5500 rpm or more, it is determined in step # 9 whether the engine load is full load. If the determination result in step # 9 is NO, that is, if the engine load is not full load, in step # 7, the premixing injection ratio is increased, and the premixing injector I _{2 is} increased with this increased injection ratio. hydrogen injection is performed by the direct injector I ₁ (step # 8).

On the other hand, when the result of the determination in step # 9 is YES, i.e., when the engine load is a full load, at step # 10, so as to provide only the hydrogen from the premixed injector I ₂ premixed injection only Switch. When switching to premixed injection only, the intake air amount can be reduced and the NOx emission amount can be increased. In this embodiment, in step # 11, the air-fuel ratio is made lean, that is, the air side leaner than the stoichiometric air-fuel ratio. After correcting the hydrogen injection amount to reduce the hydrogen injection amount from the premixing injector I ₂ so as to become the fuel ratio, hydrogen injection is executed by the premixing injector I ₂ that injects and supplies the hydrogen injection amount ( Step # 12). In this embodiment, for example, λ = 2 is set to make the air-fuel ratio lean.

As described above, in the present embodiment, when the engine control unit 30 determines that the predetermined torque-down control condition is satisfied, the engine speed is equal to or higher than the predetermined speed and the engine load is in the full load range. the hydrogen feed rate so as to provide only the hydrogen from the premixed injector I ₂ increases the feed rate of hydrogen from the premixed injector I ₂ in the case where there is a high rotation and operating conditions of full load region A7, A8 It controls amount of hydrogen supplied from the premixed injector I ₂ such that the air-fuel ratio leaner than the stoichiometric air-fuel ratio to control the, when in the high rotation and the operation state other than the full load region A7, A8 is , controls the hydrogen supply rate to increase the feed rate of hydrogen from the premixed injector I _2.

  In this embodiment, in order to satisfy a predetermined torque reduction request, the hydrogen supply ratio is “8: 2”, “8.5: 1.5” at a high rotation speed and the entire operation state is switched to only premixed injection. Load areas A7 and A8 are set. For example, depending on other torque reduction requests such as the traction control unit 50, an area where the hydrogen supply ratio is “6: 4” to “8.5: 1.5”, for example. Settings corresponding to the amount of torque reduction may be performed, for example, the operation states of A4 to A8 are set.

Thus, when the engine control unit 30 sets the hydrogen supply ratio of the hydrogen supplied from the direct injection injector I ₁ and the premixing injector I ₂ and determines that the torque-down control condition is satisfied, by increasing the feed rate of hydrogen supplied from the premixed injector I _2, for example, when aT car speed, when a predetermined torque reduction request, increasing the feed rate of the gaseous hydrogen by premixing injector I _2, Since the torque is reduced by suppressing the amount of air filled in the working chamber E, it is not necessary to retard the ignition timing, and the torque can be reduced with good responsiveness while suppressing the occurrence of backfire.

Further, the engine control unit 30, when the torque reduction control condition is determined to be satisfied, when in the operating condition of high rotational and full load region A7, A8 may only hydrogen from premixed injector I ₂ By supplying the air-fuel ratio and setting the air-fuel ratio to a lean value at which the NOx emission amount is approximately zero, it is possible to suppress pre-ignition by reducing the air-fuel ratio while suppressing the deterioration of the NOx emission amount.

  In this way, when it is determined that the torque-down control condition is satisfied, the engine control unit 30 suppresses the deterioration of the NOx emission amount and suppresses the occurrence of backfire in the operation state of the entire region. However, the torque can be reduced with good responsiveness.

  In the present embodiment, a rotary engine is described as the hydrogen engine 1, but the present invention can be similarly applied to other types of engines such as a reciprocating engine.

  As described above, the present invention is not limited to the illustrated embodiments, and it goes without saying that various improvements and design changes can be made without departing from the gist of the present invention.

  The present invention is a fuel control device for a hydrogen engine including a direct injection injector that directly injects gaseous hydrogen into a working chamber and a premixing injector that injects and supplies gaseous hydrogen into an intake passage. For example, the present invention can be suitably applied to a vehicle equipped with a hydrogen engine equipped with the direct injection and premixing injectors.

It is explanatory drawing which shows roughly the rotary type hydrogen engine which concerns on embodiment of this invention. It is explanatory drawing which shows notionally the said hydrogen engine and the structure relevant to it. It is a figure which shows the map used for control of the hydrogen injection of the direct injection injector which concerns on this embodiment, and a premixing injector. It is a control flowchart of the direct injection injector and premixing injector which concern on this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydrogen engine 3 Intake passage 5 Exhaust passage 11 Engine speed sensor 12 Air quantity sensor 14 Throttle valve 15 Oxygen concentration sensor 30 Engine control unit 40 Automatic transmission control unit 50 Traction control unit E Working chamber I ₁ Direct injection injector I ₂ Premix Injector

Claims (3)

Fuel control for a hydrogen engine comprising a first hydrogen supply means for injecting and supplying gaseous hydrogen directly into the working chamber, and a second hydrogen supply means for injecting and supplying gaseous hydrogen into the intake passage communicating with the working chamber A device,
Determining means for determining whether or not a predetermined torque-down control condition is satisfied;
A hydrogen supply ratio of hydrogen supplied from the first hydrogen supply unit and the second hydrogen supply unit is set according to an operating state of the hydrogen engine, and a predetermined torque down control condition is established by the determination unit. When it is determined that the hydrogen supply ratio is determined, the hydrogen supply ratio control means controls the hydrogen supply ratio so as to increase the hydrogen supply ratio supplied from the second hydrogen supply means with respect to the set hydrogen supply ratio. When,
A fuel control device for a hydrogen engine, comprising: The hydrogen supply ratio control means is configured to obtain a hydrogen supply ratio of hydrogen supplied from the first hydrogen supply means and the second hydrogen supply means from the second hydrogen supply means according to an increase in engine speed. Set to increase the supply rate of supplied hydrogen,
The fuel control device for a hydrogen engine according to claim 1. The hydrogen supply ratio control means, when it is determined by the determination means that a predetermined torque down control condition is satisfied,
When the engine speed is equal to or higher than a predetermined speed and the engine load is in a high speed and full load range operation state, the hydrogen is supplied only from the second hydrogen supply means. Controlling the supply rate and controlling the hydrogen supply amount from the second hydrogen supply means so that the air-fuel ratio is leaner than the stoichiometric air-fuel ratio;
When in an operating state other than the high rotation and full load range, the hydrogen supply rate is controlled to increase the supply rate of hydrogen supplied from the second hydrogen supply means;
The fuel control apparatus for a hydrogen engine according to claim 1 or 2, wherein

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