JPH0617708A - Hydrogen engine fuel supply system - Google Patents

Abstract

(57) [Summary] [Purpose] When switching and using two hydrogen storage tanks, one for starting and one for running, according to the state of the engine,
Prevents deterioration of combustibility due to lack of fuel during switching. [Structure] A hydrogen storage tank 5 for starting, which releases hydrogen in a low temperature state, a hydrogen storage tank 4 for traveling, which releases hydrogen in a higher temperature state than the hydrogen storage tank for starting, and supplies the released hydrogen to an engine. And a hydrogen intake passage 6 for supplying hydrogen. A hydrogen pressure sensor 24 for detecting the pressure of hydrogen released from the traveling hydrogen storage tank is provided, and when the detected hydrogen pressure value is lower than a set value, the first hydrogen valve 22 is opened to set the starting hydrogen storage tank to the hydrogen supply passage. The second hydrogen valve 2 when the hydrogen pressure detection value is higher than the set value.
A switching control means 48 is provided which opens 3 to switch the running hydrogen storage tank to communicate with the hydrogen supply passage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supply device for supplying hydrogen as a fuel to a hydrogen engine.

[0002]

2. Description of the Related Art Conventionally, as a fuel supply device for a hydrogen engine of this kind, a hydrogen storage tank containing a hydrogen storage alloy for storing and releasing hydrogen is provided, and the hydrogen storage alloy is cooled by cooling the hydrogen storage tank. It is known that after hydrogen is stored in the hydrogen storage tank, the hydrogen storage tank is heated by engine cooling water to release the hydrogen stored in the hydrogen storage alloy and supply the hydrogen to the engine (for example, See Japanese Patent Laid-Open No. 1-216024).
Generally, as the hydrogen storage tank is heated, the amount of released hydrogen increases and the pressure of the hydrogen increases.

[0003]

However, in the above-described conventional fuel supply device for a hydrogen engine, since the hydrogen storage tank is heated by the engine cooling water, the amount of hydrogen released during engine cooling such as at the time of start-up. However, there is a drawback that the air-fuel ratio of the air-fuel mixture is too lean and the startability is not good. Therefore, a hydrogen storage tank for starting, which releases hydrogen at a temperature lower than that of the hydrogen storage alloy of the hydrogen storage tank, is separately provided in addition to the hydrogen storage tank, and the starting hydrogen is used when the engine is cold at the time of starting. It is conceivable to use hydrogen from the storage tank and switch to the original hydrogen storage tank to use the hydrogen from the hydrogen storage tank when the engine cooling water reaches a predetermined temperature or higher after warming up. That is, it is conceivable that the original hydrogen storage tank is used for running, the startup hydrogen storage tank is used when the engine is cold, and the switching is performed using the water temperature of the engine cooling water as an index.

However, when the temperature of the engine cooling water is switched as an index, it takes a certain time from the heating of the hydrogen storage tank with the engine cooling water until the hydrogen storage alloy releases hydrogen. As a result, a response delay occurs, and due to this response delay, fuel shortage may occur at the time of switching, resulting in deterioration of combustibility.

Further, the amount of hydrogen released from the hydrogen storage alloy is not only determined by the heating temperature, but also changes by the amount of hydrogen adsorbed to the hydrogen storage alloy, that is, the amount of hydrogen remaining in the hydrogen storage tank. . That is, FIG.
As shown in 2, the released hydrogen pressure, that is, the released amount of hydrogen decreases as the amount of adsorbed hydrogen decreases even at the same heating temperature. Therefore, even when a heat source other than the engine cooling water is used as the heat source for releasing hydrogen from the hydrogen storage tank, as long as the heating temperature such as the engine cooling water temperature is used as an index only, the hydrogen storage tank Depending on the remaining amount of hydrogen, the fuel shortage may occur at the time of switching as in the case of the response delay.

The present invention has been made in view of the above circumstances, and an object thereof is to use two hydrogen storage tanks, one for starting and one for traveling, to switch and use according to the state of the engine. In doing so, it is to obtain good combustibility without causing deterioration of combustibility due to fuel shortage at the time of switching.

[0007]

In order to achieve the above object, the invention described in claim 1 is, for example, as shown in FIG.
First hydrogen storage tank 5 that releases hydrogen in a predetermined low temperature state
A second hydrogen storage tank 4 that releases hydrogen at a temperature higher than that of the first hydrogen storage tank 5, and a hydrogen supply system 6 that supplies the released hydrogen to the engine 1.
The hydrogen pressure detecting means 24 for detecting the pressure of hydrogen released from the second hydrogen storage tank 4 and the output from the hydrogen pressure detecting means 24 are received, and when the hydrogen pressure is lower than a set value, A switching control means for connecting the first hydrogen storage tank 5 to the hydrogen supply system 6 and switching the second hydrogen storage tank 4 to communicate with the hydrogen supply system 6 when the hydrogen pressure is higher than the set value. 48
And a configuration including.

[0008]

With the above construction, in the invention according to claim 1,
Hydrogen released from the first hydrogen storage tank 5 is supplied to the engine until the pressure of the hydrogen released from the second hydrogen storage tank 4 reaches the set pressure, and the hydrogen pressure reaches the set pressure. The switching control means 48 switches from the first hydrogen storage tank 5 to the second hydrogen storage tank 4. That is, at the time of starting the engine 1 in the cold state, hydrogen from the first hydrogen storage tank 5 that releases hydrogen even in a low temperature state is supplied to the engine 1 through the hydrogen supply system 6 from the first hydrogen storage tank 5. When the second hydrogen storage tank 4 is warmed while the hydrogen is being supplied and the hydrogen pressure reaches the set pressure, the switching control means 48 switches the hydrogen pressure, and thereafter the second hydrogen storage tank 4 is switched. The engine 1 is burned by the hydrogen supplied from. That is, the switching is performed using not the indirect index of the engine cooling water temperature but the hydrogen pressure directly corresponding to the hydrogen supply amount to the engine 1 as the index. Therefore, there is no delay in response when the engine cooling water temperature is used as an index, and moreover, regardless of the remaining amount of hydrogen in the second hydrogen storage tank 4, it is possible to ensure that the hydrogen at the predetermined pressure is kept. Supply is made.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 shows the overall structure of a hydrogen rotary piston engine (hereinafter, simply referred to as an engine) 1 equipped with a fuel supply device according to an embodiment of the present invention, and 2 supplies air to the engine 1. Intake passage 3, 3 is an exhaust passage for discharging exhaust gas from the engine 1 to the outside, 4 is a traveling metal hydride tank as a second hydrogen storage tank (hereinafter abbreviated as traveling MH tank), 5 is a first hydrogen storage tank A metal hydride tank for start-up (hereinafter abbreviated as MH tank for start-up), 6 is a hydrogen supply system for supplying hydrogen gas as fuel to the engine 1 from the MH tanks 4 and 5 for running or starting. A supply passage, 7 is an engine cooling water circulation passage for circulating engine cooling water, and 8 is the traveling or starting MH tanks 4, 5
A control unit (hereinafter abbreviated as ECU) that controls the supply of hydrogen gas from the.

The engine 1 has a rotor housing 9 having a peritrochoid curve as an inner peripheral surface, and a pair of side housings 10 mounted on both side surfaces of the rotor housing 9.
(Only one is shown in FIG. 2), and a cylinder 11 is formed by these housings 9 and 10.
A substantially triangular rotor 12 having three inner envelope surfaces is housed in the cylinder 11.
The three ridges come into airtight contact with the inner peripheral surface of the rotor housing 9 via the apex seals, whereby three working chambers 13, 13, 13 are formed between the rotor 12 and the housings 9, 10. It is compartmentalized.

The rotor 12 is supported by an eccentric shaft 14 so as to be eccentrically rotatable. The eccentric rotation of the rotor 12 causes the volume of each working chamber 13 to change so that intake, compression, expansion (explosion), and exhaust can be performed. The eccentric shaft 14 is rotationally driven by sequentially performing each process.

An intake port 15 and a hydrogen supply port 16 are formed in the side housing 10 independently of each other and open toward the working chamber 13 in the intake stroke of the cylinder 11. The intake port 15 is in communication with the downstream end of the intake passage 2, and the hydrogen supply port 16 is in communication with the downstream end of the hydrogen supply passage 6.

The rotor housing 9 has the cylinder 11 therein.
An exhaust port 17 is formed so as to open toward the working chamber 13 in the exhaust stroke, and the exhaust port 17 communicates with the upstream end of the exhaust passage 3.

The rotor housing 9 is a portion corresponding to the working chambers 13, 13 in the compression and expansion strokes of the cylinder 11, and has spark plugs 18 at a leading side position and a trailing side position in the rotor rotating direction. Are installed respectively. Each of the spark plugs 18 is connected to an igniter coil 19 and is ignited at a predetermined timing by a secondary current supplied from the igniter coil 19.

In the intake passage 2, an air cleaner and an air pump (not shown) are provided at the upstream end side position, and the air throttle valve 2 is provided.
0 is arranged at each intermediate position. The air throttle valve 20 is adapted to be opened and closed by driving a DC motor 21, and the DC motor 21 is driven by a control signal from the ECU 8. That is, the air throttle valve 20 is controlled by the ECU 8 based on the operation amount of the accelerator 30 described later, the opening degree of the hydrogen flow rate adjusting valve 27, the outputs of the intake air temperature sensor and the air pressure sensor (not shown), and the predetermined value. A flow rate of air is supplied to the cylinder 11
It is designed to be supplied to.

The traveling MH tank 4 has a hydrogen storage alloy capable of storing and releasing hydrogen therein.
This hydrogen storage alloy stores hydrogen by the hydrogen invading between the metal crystal lattices forming a metal hydride, and by cooling, the production of the metal hydride proceeds to store hydrogen, and conversely, It has the property of releasing hydrogen by heating. Then, a heating water passage 40 described later
It is heated by the engine cooling water circulated through it, and hydrogen is released at a maximum hydrogen pressure of approximately 9 kg / cm @ 2.

The starting MH tank 5 is the running MH tank.
It has a smaller capacity than the tank 4. This MH for starting
The tank 5 is internally provided with a hydrogen storage alloy having a characteristic different from that of the hydrogen storage alloy of the traveling MH tank 4, and releases hydrogen at a temperature lower than that of the traveling MH tank 4. That is, the hydrogen storage alloy of the starting MH tank 5 is lower than the temperature at which the running MH tank 4 starts to release hydrogen without originally requiring heating by the engine cooling water, for example, at a low temperature of 30 to less than 40 ° C. Even in the state, it has a characteristic of releasing hydrogen at a predetermined pressure (for example, about 20 Kg / cm @ 2). As a hydrogen storage alloy having such characteristics, for example, one represented by a chemical formula of MmNi _4.42 , Fe _0.48 , Co _0.1 (where Mm is misch metal) may be used.

The upstream end side of the hydrogen supply passage 6 is branched into two, one of which is connected to the starting MH tank 5 through a first hydrogen valve 22 and the other of which is connected through a second hydrogen valve 23. And is connected to the traveling MH tank 4. The first or second hydrogen valve 22, 23 is an EC
It is designed to be opened and closed by a control signal from U8, which is fully opened by an ON operation signal and fully closed by an OFF operation signal. With this fully closed state, the traveling or starting MH tanks 4 and 5 are in a hermetically sealed state and are disconnected from the hydrogen supply passage 6. Further, a hydrogen pressure sensor 24, which is a hydrogen pressure detecting means, is arranged between the traveling MH tank 4 and the second hydrogen valve 23. The hydrogen pressure sensor 24 is connected to the traveling MH tank 4 from the traveling MH tank 4. The pressure of the released hydrogen is detected and output to the ECU 8. The first and second hydrogen valves 22 and 23 are controlled by the ECU 8 and the hydrogen supply passage 6 is controlled.
MH tank 5 for starting or MH for traveling that releases hydrogen to the
The tank 4 is switched.

The hydrogen supply passage 6 is merged on the downstream side of the first and second hydrogen valves 22 and 23, and then arranged in order from the upstream side to the hydrogen supply port 16 at the downstream end. A third hydrogen valve 25 for opening and closing the hydrogen supply passage 6, a pressure regulator 26, and a hydrogen flow rate regulating valve 27.
And a hydrogen injection valve 2 provided in the hydrogen supply port 16
8 and.

The third hydrogen valve 25 is adapted to be opened / closed by a control signal from the ECU 8, and is fully opened by an ON operation signal and fully closed by an OFF operation signal. The third hydrogen valve 25 is selectively switched to a fourth hydrogen valve 33, which will be described later, so that the traveling or starting MH tanks 4 and 5 can be operated.
The supply of hydrogen from the vehicle to the engine 1 and the charging of the running or starting MH tanks 4 and 5 with hydrogen are switched.

The pressure regulator 26 supplies hydrogen gas supplied through the third hydrogen valve 25 to approximately 5 kg / cm ^2.
It is designed to regulate the pressure. That is, 5 kg / cm
Hydrogen gas higher than ² the pressure to approximately 5Kg / cm ² under reduced pressure, the hydrogen gas pressure below 5Kg / cm ² is as pass it.

The hydrogen flow rate adjusting valve 27 is a DC motor 29.
The DC motor 29 is driven by the control signal from the ECU 8. That is, the hydrogen flow rate adjusting valve 27 is controlled by the ECU 8 based on the operation amount of the accelerator 30 and the flow rate detected by a hydrogen flow meter (not shown) to supply a predetermined amount of hydrogen gas to the hydrogen injection valve 28. It has become.

The hydrogen injection valve 28 is connected to the eccentric shaft 14 via a timing belt 31 and is opened / closed at a predetermined timing in mechanical synchronization with the rotation of the eccentric shaft 14. That is, the hydrogen injection valve 28 is opened near the closing timing of the intake port 15 and injects hydrogen gas from the hydrogen supply port 16 which is opened after the intake port 15 in the opening stage of the cylinder 11 in the initial stage of the compression stroke. It is like this.

The first and second hydrogen valves 2 are also provided.
Hydrogen supply passage 6 between the second hydrogen valve 23 and the third hydrogen valve 25
An upstream end of a hydrogen filling passage 32 is connected to the hydrogen filling passage 32.
A hydrogen valve 33 is provided. The fourth hydrogen valve 33 is adapted to be opened / closed by a control signal from the ECU 8, and is fully opened in response to an ON operation signal.
The F actuation signal causes a fully closed state. Then, the above-mentioned first to fourth hydrogen valves 22, 23, 25, 3
The ECU 3 is controlled by the ECU 8 so that the traveling MH tank 4 and the starting MH tank 5 are filled with hydrogen separately.

The engine cooling water circulation passage 7 includes water jackets 34a and 34b of the rotor housing 9 and
The engine cooling water is circulated between the radiator 35 and the radiator 35, and the engine cooling water heated by the combustion of the engine 1 is led out from the one end 34a of the water jacket to the radiator 35, and the radiator 35. It is provided with an introduction passage 37 for returning the engine cooling water cooled in step 2 to the other end 34b of the water jacket, and two electric water pumps 38, 39 for forcibly circulating the engine cooling water.

At the position of the outlet passage 36 on the engine 1 side, one end of the heated water inlet passage 40 has a first heat medium valve 41.
The heating water passage 40 is branched from the intermediate position and the downstream end of the one 40a is connected to one end of the traveling MH tank 4, and the downstream end of the other 40b is connected to the second heat medium valve 4.
2 is connected to one end of the starting MH tank 5 respectively. On the other hand, one end of the heated water outlet passage 43a is connected to the other end of the traveling MH tank 4, and one end of another heated water outlet passage 43b is connected to the other end of the starting MH tank 5, respectively. The other ends of the passages 43a and 43b are connected to and communicate with an intermediate position of the introduction passage 37 of the engine cooling water circulation passage 7. The heating water inlet passage 40 and the heating water outlet passages 43a and 43b are controlled by the ECU 8 to open and close the first heat medium valve 41, and mainly the engine cooling water heated by the engine is used for the traveling MH tank 4. The engine cooling water is used as a heat source to release hydrogen from the traveling MH tank 4.

The downstream end of the cooling water supply passage 44 is connected to the confluence of the two branch passages 40a and 40b of the heating water introduction passage 40, and the intermediate position of the heating water outlet passage 43b on the side of the starting MH tank 5 is connected. The upstream end of the cooling water drainage passage 45 is connected to. Then, the second heat medium valve 42 and the like are controlled by the ECU 8 and the running water is forcibly supplied by the cooling water such as tap water that is forcibly supplied from the water supply port 46 which is the upstream end of the cooling water supply passage 44. Cooling is performed when the MH tank 4 and the MH tank 5 for starting are filled with hydrogen.

The two water pumps 38 and 39 are E
Each of them is driven by a control signal from the CU 8, and the circulating flow rate of the engine cooling water is changed in a plurality of steps. That is, the circulating flow rate can be changed depending on the state in which both water pumps 38 and 39 are driven, the state in which one is stopped and the other is driven, and the state in which one is stopped and the other is intermittently driven. You can do it.

In FIG. 2, reference numeral 47 is a metering oil pump for supplying oil into the cylinder 11 to lubricate the seal.
It is driven by a control signal from the CU 8 to discharge a predetermined amount of oil according to the condition of the engine 1.

The ECU 8 has the above-mentioned air throttle valve 20,
In addition to controlling the hydrogen flow rate adjusting valve 27, the metering oil pump 47, and the like, all the hydrogen supply, supply stop, injection, and other fuel supply control are performed. Supply MH tank 5 for starting to MH tank 4 for running according to hydrogen pressure
The switching control means 48 shown in FIG. That is, the ECU 8 includes the ignition switch 49, the starter switch 50, the traveling or starting MH.
Injection switch 5 for selecting hydrogen filling in tanks 4 and 5
1, the MH tank for running or starting with hydrogen filling 4,
Based on outputs from the injection changeover switch 52 for selecting the changeover to 5, the kill switch 53 for selecting the emergency stop, the hydrogen pressure sensor 24, the rotation speed sensor 54, and the like,
The first to fourth hydrogen valves 22, 23, 25, 33, the first and second water pumps 38, 39, and the first and second
The opening / closing and drive of the heat medium valves 41, 42 and the like are controlled.

Next, fuel supply control by the ECU 8 will be described with reference to FIGS. The fuel supply control consists of a main routine and a plurality of subroutines,
The subroutine to be processed by the main routine is discriminated and determined based on the output from the ignition switch 49 or the like.

In the main routine, as shown in FIG. 4, the ignition switch 49 is turned on in step S1.
If it is turned on, it is determined in step S2.
It is determined whether or not the starter switch 50 is turned on. If this starter switch 50 is ON,
When it is determined that the engine is starting, the warm-up routine SUB1 that supplies the engine 1 with hydrogen released from the starting MH tank 5 is executed. Then, in step S3, it is determined whether or not the kill switch 53 has been turned on, and if it is turned on, the emergency stop routine SUB3 is executed, and OF
If it remains F, it returns. The emergency stop routine SUB3 performs interrupt processing by detecting the ON operation of the kill switch 53 even when any of the subroutines such as the warm-up routine SUB1 is being executed.

If the starter switch 50 is in the OFF state in step S2, it is determined that the warm-up operation is in progress after the start operation, and in step S4 the value detected by the rotation speed sensor 54 is a predetermined rotation speed (eg, (500 rpm) or higher. If it is less than 500 rpm, it is determined that the engine is in the stalled state, and the stop / store routine SUB4 is executed. If the detected value is 500 rpm or more, it is determined in step S5 whether or not the detected value of the hydrogen pressure sensor 24 is a predetermined set pressure value (for example, 5 Kg / cm2) or more, and it is 5 Kg / cm2 or more. If so, the running routine SUB2 is executed, and if it has not yet reached 5 kg / cm2, the warm-up routine SUB1 is continued. That is,
As the engine 1 that has been in a cold state by the fuel supply by the warm-up routine SUB1 is warmed up, the engine cooling water temperature rises, and the traveling MH heated by this engine cooling water
When the pressure of hydrogen released from the tank 4 is raised to a pressure (above set pressure) that can be supplied to the engine 1 through the hydrogen supply passage 6, the running routine SUB2 is switched to the running routine SUB2 that supplies hydrogen from the running MH tank 4. If the pressure has not been increased yet, the warm-up routine SUB1 for supplying hydrogen from the starting MH tank 5 is continued.

On the other hand, if the ignition switch 49 is not turned on in step S1, it is determined in step S6 whether the injection switch 51 is turned on. If the injection switch 51 is not turned on, the stop / store routine SUB4 is executed. If the injection switch 51 is turned on, the operation position of the injection changeover switch is determined in step S7. If the injection operation position to the traveling MH tank 4 is switched, the traveling tank injection routine SUB5 is started. Tank injection routine for starting SUB if the operation position is changed to the injection MH tank 5
6 respectively. Even if the ignition switch 49 is not turned on, that is, even when the ignition switch 49 is turned off, the EC is turned on by operating the injection switch 51.
The internal power supply of U8 is turned on and the subsequent processing is performed.

Step S5 in the main routine
However, when the hydrogen pressure in the traveling MH tank 4 is increased to the above set pressure, the hydrogen supply is started and the starting MH tank 5 is supplied.
The switching control means 48 for switching from the vehicle to the traveling MH tank 4 is configured.

In the warm-up routine SUB1, as shown in FIG. 5, first, in step S8, the second and fourth hydrogen valves 23, 33 are turned off (closed), and the first and third hydrogen valves 22, 25 are turned on. Turn it on (open). As a result, the hydrogen released from the starting MH tank 4 is supplied to the engine 1 in a state in which the pressure is reduced to 5 Kg / cm 2 by the pressure regulator 26. Next, in step S9, the first heat medium valve 41 is turned on (open) and the second heat medium valve 42 is turned off (closed) so that the engine cooling water can be introduced into the heating water introducing passage 40. To do. Then, in step S10, the first
Then, both the second water pumps 38 and 39 are turned on (driven) to guide the engine cooling water whose temperature has risen due to the warm-up of the engine 1 to the traveling MH tank 4 through the heating water passage 40 to cool the engine. MH for running with water
The tank 4 is actively heated. Then return.

In the traveling routine SUB2, as shown in FIG. 6, the first and fourth hydrogen valves 2 are set in step S11.
2, 33 are turned off and the second and third hydrogen valves 2
Turn on 3,25. That is, the traveling MH tank 5
Since the hydrogen released from was above the set pressure above,
The hydrogen supply from the starting MH tank 5 in the warm-up routine SUB1 is switched to the hydrogen supply from the traveling MH tank 4. Then, in step S12, the first heat medium valve 4
1 is maintained in the ON state and the second heat medium valve 42 is maintained in the OFF state, and the hydrogen pressure from the traveling MH tank 4 is set to a predetermined upper limit value a shown in FIG. 7 (for example, 7 kg / cm ² ) and the lower limit value b (for example, 5 Kg
The drive of the first and second water pumps (WP) 38, 39 is controlled so as to maintain the range of / cm ² ).

That is, it is determined in step S13 whether or not the detected value of the hydrogen pressure sensor 24 is higher than the upper limit value a, and if it is higher, the driving of the first and second water pumps 38, 39 is turned off in step S14. To return.
If the detected value is lower than the upper limit value a, it is further determined in step S15 whether or not the detected value is lower than or equal to the lower limit value b. If it is higher than the lower limit value b, in step S16 the first and second waters are detected. The pumps 38 and 39 are maintained in the previous driving state. On the other hand, if it is equal to or lower than the lower limit value b, the process proceeds to step S17, where the rotation speed sensor 54
The detected value of is a predetermined low rotation speed (for example, 1000 rpm)
It is determined whether or not the following. If it is 1000 rpm or less, the first water pump 38 is turned on in step S18.
The second water pump 39 is turned off in the intermittent driving state in which it is alternately turned off.

If the detected rotation speed is not lower than 1000 rpm in step S17, the process proceeds to step S19, and the detected rotation speed is changed from 1000 to 2 in step S19.
It is determined whether or not it is within the range of 000 rpm. If it is within this range, turn on the first water pump in step S20.
Set to N and turn off the second water pump. If it is not within the above range and the detected rotation speed is higher than 2000 rpm, both the first and second water pumps 38 and 39 are turned on. That is, when the hydrogen pressure is equal to or lower than the lower limit value b, by controlling the driving of the first and second water pumps 38 and 39 according to the engine speed,
The circulation rate of the engine cooling water is changed in three stages to adjust the heating degree. Then, in the case where the engine speed is a low speed of 1000 rpm or less, one water pump 38 is operated in step S18 so as not to be rapidly heated and suddenly exceed the upper limit value a.
Only the water pump 38 is driven, and the water pump 38 is intermittently driven. In this way, by controlling the driving of the first and second water pumps 38 and 39 to change the circulation amount of the engine cooling water in a plurality of stages, the pressure of hydrogen released from the traveling MH tank 4 is changed to the engine pressure. It can be reliably adjusted to a predetermined range according to the rotation speed.

In the emergency stop routine SUB3, as shown in FIG. 8, in steps S22, the first to fourth hydrogen valves 2 are connected.
All of 2, 23, 25 and 33 are turned off to disconnect the hydrogen supply passage 6 and both MH tanks 4 and 5. And
In step S23, the first and second heat medium valves 41, 4
2 is turned off, the driving of the first and second water pumps 38, 39 is turned off in step S24, and the supply of the heat source by the engine cooling water is stopped. As a result, the supply of hydrogen as fuel is stopped, so that the engine 1 naturally stops.

The stop / save routine SUB4 shown in FIG.
As shown in step S25, all of the first to fourth hydrogen valves 22, 23, 25, 33 are turned off in step S25, and the hydrogen supply passage 6 and both MH tanks 4, 5 are connected in the same manner as in the emergency stop routine SUB3. Cut off. And step S2
In step 6, the first and second heat medium valves 41 and 42 are turned off, and in step S27, the drive of the first and second water pumps 38 and 39 is turned off to stop the supply of the heat source by the engine cooling water. .

The running tank filling routine SUB5
10, the first and third hydrogen valves 22, 25 are turned off and the second and fourth hydrogen valves 23, 33 are turned on in step S28, as shown in FIG. As a result, the hydrogen filling passage 32 and the traveling MH tank 4 are communicated with each other.
Next, in step S29, the second heat medium valve 42 is turned off.
Then, the first heat medium valve 41 is turned on, and step S3 is performed.
0 turns off the first and second water pumps 38, 39
To In this state, cooling water is supplied from the water supply port 46 to the traveling MH tank 4 through the cooling water supply passage 44, and while the traveling MH tank 4 is cooled, hydrogen is supplied to the traveling MH tank 4 through the hydrogen filling passage 32. Filling, ie
Fuel may be injected.

The starting tank filling routine SUB6
11, the second and third hydrogen valves 23 and 25 are turned off and the first and fourth hydrogen valves 22 and 33 are turned on in step S31. As a result, the hydrogen filling passage 32 and the starting MH tank 5 are communicated with each other. Next, in step S32, the second heat medium valve 42 is turned on.
Then, the first heat medium valve 41 is turned off, and the first and second water pumps 38 and 39 are turned on in step S33.
Set to FF. In this state, the cooling water is supplied from the water supply port 46 to the starting MH tank 5 through the second heat medium valve 42 to cool the starting MH tank 5 while cooling the hydrogen filling passage 3
It is sufficient to fill the starting MH tank 5 with hydrogen through 2, that is, to inject fuel.

Cooling by the cooling water in the running tank injection routine SUB5 and the starting tank routine SUB6 generates heat due to the adsorption of hydrogen to the internal hydrogen storage alloy, which lowers the adsorption capacity. It is performed to promote adsorption.

In the fuel supply system for the hydrogen engine, when the starter switch 50 is turned on and the engine 1 is started, the engine is in a cold state and the engine cooling water is still in a low temperature state and is discharged from the traveling MH tank 4. Since the hydrogen pressure has not risen to a pressure (set pressure value 5 Kg / cm ² ) that can be supplied by the hydrogen supply passage 6, the warm-up routine SUB1 is executed and the hydrogen released from the starting MH tank 5 is It is supplied to the engine 1. Since the starting MH tank 5 can release hydrogen at a pressure that can be supplied by the hydrogen supply passage 6 even in a low temperature state corresponding to the cold state, the combustibility is not deteriorated at the time of starting, and a good starting is achieved. It can be performed.

After the start, the temperature of the engine cooling water rises as the engine warms up due to the combustion of hydrogen from the start MH tank 5, which increases the heating degree of the running MH tank 4. The pressure of the released hydrogen rises. When the hydrogen pressure from the traveling MH tank 4 is increased to 5 kg / cm ² , the switching control means 48 switches from the warm-up routine SUB1 to the traveling routine SUB2, and as a result, the hydrogen is supplied to the hydrogen supply passage 6. The hydrogen source from the starting MH tank 5 to the traveling MH
It is switched to the tank 4. In the subsequent normal traveling state, the engine 1 is driven by the hydrogen released from the traveling MH tank 4.

As described above, since the starting MH tank 5 is switched to the traveling MH tank 4 using the pressure of hydrogen actually supplied to the hydrogen supply passage 6 as an index, the hydrogen is supplied to the engine 1 at the time of switching. The generated hydrogen pressure, that is, the situation where the hydrogen supply amount is insufficient can be prevented from occurring, and the deterioration of the combustibility due to the hydrogen supply amount insufficient can be prevented. Therefore, it is possible to prevent a response delay that may occur when switching is performed using an indirect index of engine cooling water temperature in the conventional device, and it is possible to improve combustibility.

Moreover, since the switching is performed using the hydrogen pressure as an index, even when the rate of increase in the amount of released hydrogen relative to the increase in the degree of heating is low when the remaining amount of hydrogen in the traveling MH tank 4 is small, The above switching is not performed until the switching hydrogen pressure is reached, and thereby hydrogen can be reliably supplied at a predetermined pressure regardless of the remaining amount of hydrogen.

The present invention is not limited to the above embodiment, but includes various other modifications. That is, in the above embodiment, the case where the present invention is applied to the hydrogen rotary piston engine is shown, but the present invention is not limited to this, and may be applied to a reciprocating engine that uses hydrogen as fuel. Even in this case, the same action and effect as those of the hydrogen rotary piston engine can be obtained.

In the above-described embodiment, the switching control means 48 is configured to switch using only hydrogen pressure as an index. However, the present invention is not limited to this, and in addition to the hydrogen pressure, for example, a water temperature sensor 55 (see FIG. 2). The engine cooling water temperature detected by the above) may be used as an index, and the switching may be performed based on both indexes. For example, whether or not the traveling MH tank has been heated to a temperature at which hydrogen can be supplied is determined by the engine cooling water temperature, and even if the temperature has reached a predetermined temperature, the hydrogen pressure is set due to a decrease in the remaining amount of hydrogen or the like. If the pressure has not been reached, it may be controlled so that the timing of switching from the starting MH tank to the traveling MH tank is delayed until the set pressure is reached.

Although the engine cooling water is used as the heat source for the traveling MH tank 4 in the above embodiment, the present invention is not limited to this, and other heating means may be used.

Further, in the above embodiment, the switching hydrogen pressure of the switching control is set to 5 Kg / cm 2, but the invention is not limited to this, and it may be set according to the pressure at which hydrogen can be supplied to the engine 1 through the hydrogen supply passage. . Therefore, it may be determined according to the configuration of the hydrogen supply passage and the hydrogen release characteristic of the traveling MH tank.

[0054]

As described above, according to the fuel supply system for a hydrogen engine of the invention described in claim 1, the hydrogen from the starting MH tank (first hydrogen storage tank) is started during normal running. By supplying hydrogen from the special MH tank (second hydrogen storage tank) to the engine, when the engine is in a cold state, good starting can be performed without deteriorating the combustibility at the time of starting. Also,
Since the switching from the starting MH tank to the traveling MH tank is performed using the pressure of hydrogen actually supplied to the hydrogen supply system as an index, the hydrogen pressure supplied to the engine at the time of the switching, that is, the hydrogen supply amount. It is possible to prevent the occurrence of a shortage of hydrogen, and it is possible to prevent the deterioration of combustibility due to the shortage of hydrogen supply. Therefore, it is possible to prevent a response delay that may occur when switching is performed using an indirect index such as the engine cooling water temperature, and it is possible to improve combustibility during switching. Moreover, since the switching is performed using the hydrogen pressure as an index, the switching is not performed until the predetermined switching hydrogen pressure is reached even when the hydrogen remaining amount in the traveling MH tank is small. Therefore, it is possible to reliably supply hydrogen at a predetermined pressure regardless of the remaining amount of hydrogen.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an exemplary embodiment of the present invention.

FIG. 2 is an overall configuration diagram of a hydrogen engine.

FIG. 3 is a relationship diagram between an ECU and an input / output element.

FIG. 4 is a flowchart showing a main routine in the ECU.

FIG. 5 is a flowchart of a warm-up routine.

FIG. 6 is a flowchart of a traveling routine.

FIG. 7 is a diagram showing a relationship between elapsed time and hydrogen pressure in a traveling state.

FIG. 8 is a flowchart of an emergency stop routine.

FIG. 9 is a flowchart of a stop / store routine.

FIG. 10 is a flowchart of a traveling tank filling routine.

FIG. 11 is a flowchart of a starting tank filling routine.

FIG. 12 is a diagram showing characteristics in the case where the amount of hydrogen adsorbed in the hydrogen storage alloy is large and small in relation to the temperature and the released hydrogen pressure.

[Explanation of symbols]

 1 Engine (Hydrogen Engine) 4 MH Tank for Running (Second Hydrogen Storage Tank) 5 MH Tank for Starting (First Hydrogen Storage Tank) 6 Hydrogen Supply Passage (Hydrogen Supply System) 24 Hydrogen Pressure Sensor (Hydrogen Pressure Detection Means) 48 Switching control means

Claims (1)

[Claims] 1. A first hydrogen storage tank that releases hydrogen at a predetermined low temperature state, a second hydrogen storage tank that releases hydrogen at a higher temperature state than the first hydrogen storage tank, and the released hydrogen. A hydrogen supply system for supplying to the engine, a hydrogen pressure detecting means for detecting the pressure of hydrogen released from the second hydrogen storage tank, and an output from the hydrogen pressure detecting means, the hydrogen pressure is set to a set value or more. A switching control means for connecting the first hydrogen storage tank to the hydrogen supply system when it is low, and for connecting the second hydrogen storage tank to the hydrogen supply system when the hydrogen pressure is higher than the set value. A fuel supply device for a hydrogen engine, comprising: