JP2000012062A - Hydrogen gas supply device and hydrogen gas supply method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To repeat starting with a small capacity starting hydrogen storage tank in a hydrogen gas supply device, using a starting hydrogen storage tank and a running hydrogen storage tank and in a hydrogen gas supply method. SOLUTION: Since hydrogen is supplied from a sub-tank 14 to a fuel cell 16 in starting, hydrogen can be supplied to the fuel cell 16 without heating a tank in starting. When supply of hydrogen from a main tank 12 to the fuel cell 16 is started, hydrogen is supplied from the main tank 12 to the sub-tank 14 from which hydrogen is released in starting of the fuel cell, and stored in the sub-tank 14. Thereby, starting of the fuel cell can be repeated by using the small capacity sub-tank 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydrogen gas supply device and a hydrogen gas supply method for supplying hydrogen to a fuel cell or a hydrogen engine, and more particularly to a hydrogen gas supply device and a hydrogen gas supply method suitable for a fuel cell used as a power source of an electric vehicle. The present invention relates to a hydrogen gas supply device and a hydrogen gas supply method to be obtained.

[0002]

2. Description of the Related Art As a hydrogen gas supply device for an external load using hydrogen as a fuel, a hydrogen storage alloy for storing and releasing hydrogen is accommodated in a hydrogen storage tank, and the hydrogen storage tank is cooled to store hydrogen. After that, a method is known in which heat generated by an external load is supplied to the hydrogen storage tank to release hydrogen from the hydrogen storage alloy in the hydrogen storage tank and supply hydrogen to the external load side. In addition, the external load using hydrogen as a fuel is a unit that generates electric power or driving force using hydrogen as a fuel, and examples thereof include a fuel cell and a hydrogen engine.

[0003]

As described above, the hydrogen storage alloy releases hydrogen when it reaches a predetermined high temperature state. Therefore, as a heat source for heating to this temperature state, waste heat from the external load side is used. Is generally used. However,
At the start of the external load, no waste heat is generated, so that hydrogen cannot be supplied from the hydrogen storage tank. For this reason, a heating device for heating the hydrogen storage tank has been provided, or a surge tank for pressurizing and storing hydrogen to be supplied at the time of starting has been provided. Here, if a heating device is provided, a source of energy supply to the heating device is required, and if a surge tank capable of supplying a sufficient amount of hydrogen to the external load is provided during a period when the external load generates sufficient waste heat, the device is provided. There is a problem that the whole becomes large.

On the other hand, in order to secure the hydrogen pressure even at a low temperature, it is conceivable to use a hydrogen storage alloy having a high plateau pressure at a low temperature (a temperature lower than a predetermined temperature). At the time of storage, when the operating environment temperature increases, the pressure in the hydrogen storage tank increases, and in order to withstand the high pressure, an increase in the size of the device is inevitable.

Further, a hydrogen storage tank for starting which stores a hydrogen storage alloy capable of releasing hydrogen even at a temperature lower than a predetermined temperature, and a hydrogen storage tank for normal running which stores a hydrogen storage alloy which releases hydrogen at a high temperature are used to provide a hydrogen engine. A system in which hydrogen is supplied from the starting hydrogen storage tank at the time of start-up is proposed in JP-A-6-17708. However, in such a technique, there is a problem in filling hydrogen into a starting tank containing a hydrogen storage alloy capable of releasing hydrogen even at a low temperature. That is, when a vehicle equipped with a hydrogen engine is repeatedly started, the amount of hydrogen in the start-up tank is reduced. It is necessary to increase the capacity of the storage tank. However, since the hydrogen in the start-up tank is not used during normal traveling, a large-capacity tank is constituted by storing unused hydrogen in a hydrogen-absorbing alloy and causing the vehicle to travel. This causes a reduction in the running efficiency of a vehicle driven by a hydrogen engine and an electric vehicle running by driving a motor with electric power generated by a fuel cell. In particular, the starting hydrogen storage tank needs to be configured more robustly than the traveling hydrogen storage tank because a high hydrogen pressure is already generated in a temperature state lower than a predetermined high temperature state. This causes an increase in the size and weight of the device, and poses a serious problem when the device is mounted on a vehicle (a vehicle driven by a hydrogen engine and an electric vehicle driven by driving a motor with electric power generated by a fuel cell).

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a hydrogen gas supply apparatus and a hydrogen gas supply method using a starting hydrogen storage tank and a traveling hydrogen storage tank. It is an object of the present invention to make it possible to repeat starting using a small-capacity starting hydrogen storage tank.

[0007]

According to a first aspect of the present invention, there is provided a hydrogen gas supply device, comprising: a main hydrogen storage tank containing a high-temperature hydrogen storage alloy that releases hydrogen at a predetermined high temperature; A sub-hydrogen storage tank containing a low-temperature hydrogen storage alloy capable of releasing hydrogen at a temperature lower than a predetermined high-temperature state, a first supply path for supplying hydrogen from the main hydrogen storage tank to an external load, A second supply path for supplying hydrogen from the secondary hydrogen storage tank to an external load, a third supply path for supplying hydrogen from the main hydrogen storage tank to the secondary hydrogen storage tank, and a heat generated by the external load. A heat supply device that supplies the main hydrogen storage tank, a main pressure detection device that detects the hydrogen pressure of the main hydrogen storage tank, and a low hydrogen pressure in the main hydrogen storage tank detected by the main pressure detection device. To supply hydrogen from the sub-hydrogen storage tank to the external load via the second supply path, and when the hydrogen pressure in the main hydrogen storage tank detected by the main pressure detecting device increases, Starting the supply of hydrogen from the main hydrogen storage tank to the external load via the first supply path and supplying the hydrogen to the sub-hydrogen storage tank via the third supply path; And a supply path switching means for storing hydrogen therein.

[0008] The hydrogen gas supply apparatus according to claim 2 is claim 1.
In the above, a technical feature is that heat from the external load is not supplied to the secondary hydrogen storage tank.

A third aspect of the present invention is a hydrogen gas supply device.
Or in 2, wherein the apparatus further comprises a sub-pressure detecting device for detecting a pressure in the sub-hydrogen storage tank, and wherein the supply path switching means causes the pressure in the sub-hydrogen storage tank detected by the sub-pressure detecting device to exceed a predetermined value. In this case, a technical feature is that hydrogen is released from the secondary hydrogen storage tank to the main hydrogen storage tank via the third supply path.

According to a fourth aspect of the present invention, there is provided a hydrogen gas supply method, comprising: a main hydrogen storage tank containing a high-temperature hydrogen storage alloy for releasing hydrogen by heat supplied from an external load; A method for supplying hydrogen from a main hydrogen storage tank and a sub-hydrogen storage tank to an external load, comprising: a sub-hydrogen storage tank containing a low-temperature hydrogen storage alloy capable of releasing hydrogen; Supplying hydrogen from the secondary hydrogen storage tank to the external load when the pressure of hydrogen in the main hydrogen storage tank is low at the time of startup when sufficient heat is not supplied from the load to the main hydrogen storage tank;
When sufficient heat is supplied to the main hydrogen storage tank from the external load to increase the hydrogen pressure in the main hydrogen storage tank, supply of hydrogen from the main hydrogen storage tank to the external load is started, and A technical feature is to supply hydrogen from the main hydrogen storage tank to the sub-hydrogen storage tank and store hydrogen in the sub-hydrogen storage tank.

According to a fifth aspect of the present invention, there is provided a hydrogen gas supply method.
In the above, after the storage of hydrogen in the secondary hydrogen storage tank is started, when the pressure in the secondary hydrogen storage tank and the pressure in the main hydrogen storage tank become substantially equal, the secondary hydrogen storage tank The technical feature is to complete the storage of hydrogen.

According to a sixth aspect, in the fourth or fifth aspect, when the pressure in the secondary hydrogen storage tank exceeds a predetermined value, hydrogen is released from the secondary hydrogen storage tank to the main hydrogen storage tank. Technical features.

A seventh aspect of the present invention is characterized in that in the first to third aspects, the external load is a fuel cell.

An eighth aspect of the present invention is characterized in that, in any of the fourth to sixth aspects, the external load is a fuel cell.

According to the first and fourth aspects of the present invention, when the detected hydrogen pressure in the main hydrogen storage tank is low, hydrogen is supplied from the secondary hydrogen storage tank to an external load. For this reason, even at the time of startup, without heating the main hydrogen storage tank,
Hydrogen can be supplied to an external load. Then, when the external load is started, the heat generated by the external load is supplied to the main hydrogen storage tank, and when the hydrogen pressure in the main hydrogen storage tank increases, the main hydrogen storage tank passes through the second supply path. Start supplying hydrogen to the external load. Therefore, hydrogen can be stably supplied from the main hydrogen storage tank to the external load. Here, when starting the external load, the hydrogen in the secondary hydrogen storage tank is released and decompressed, but when starting to supply hydrogen from the main hydrogen storage tank to the external load side,
The hydrogen is supplied from the main hydrogen storage tank to the sub-hydrogen storage tank, and hydrogen is stored in the sub-hydrogen storage tank. For this reason, the start of the external load can be repeated using the secondary hydrogen storage tank having the minimum capacity required for starting the external load.

According to the second aspect of the present invention, since heat from an external load is not supplied to the secondary hydrogen storage tank, the configuration can be simplified.

According to the third or sixth aspect of the present invention, when the pressure in the sub-hydrogen storage tank exceeds a predetermined value, hydrogen is released from the sub-hydrogen storage tank to the main hydrogen storage tank. As a result, the pressure in the secondary hydrogen storage tank at which a predetermined or higher hydrogen pressure can be generated can be kept within a certain range, and it is safe.

According to the fifth aspect of the invention, after the storage of hydrogen in the secondary hydrogen storage tank is started, when the pressure in the secondary hydrogen storage tank and the pressure in the main hydrogen storage tank become substantially equal, The storage of hydrogen in the secondary hydrogen storage tank is completed.
For this reason, hydrogen can be stored in the sub hydrogen storage tank to the maximum pressure that can be realized using the hydrogen pressure of the main hydrogen storage tank.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a hydrogen gas supply device and a hydrogen gas supply method according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of the hydrogen gas supply device of the first embodiment. The hydrogen gas supply device is mounted on an electric vehicle that runs by driving a motor with electric power supplied from a fuel cell 16. In this embodiment, an example in which the fuel cell 16 is used as an external load will be described.

The hydrogen gas supply device can maintain a plateau pressure of 1 MPa or less even in a predetermined high temperature state (20 ° C. to 60 ° C.) up to an upper limit temperature (60 ° C.) which can normally be generated in a PEM type fuel cell system. Main hydrogen storage tank (running tank) 12 containing a hydrogen storage alloy for normal temperature operation to be kept
0.1MP even at low temperature (-10 ° C to 20 ° C)
a secondary hydrogen storage tank (starting tank) 14 containing a hydrogen storage alloy capable of generating a plateau pressure of a, and a fuel cell 16
(External load) generates waste heat from the main hydrogen storage tank 12
And a heat exchanger 18 for supplying to the side. The heat exchanger 18 is a device for supplying waste heat of the cooling water used for cooling during the reaction of the fuel cell 16 to the main hydrogen storage tank 12, and heat from the fuel cell 16 is used for storing the secondary hydrogen. It is not supplied to the tank 14 side. Here, when starting up the fuel cell 16, it is necessary to supply hydrogen at a pressure of 0.1 MPa or more, but the sub-hydrogen storage tank 14 is supplied to the sub-hydrogen storage tank 14 at a low temperature (for example, even at −10 ° C.). A hydrogen storage alloy capable of holding a pressure of 0.1 MPa or more is accommodated.

In this embodiment, the predetermined high temperature state is set at 20 ° C. to 60 ° C., and the predetermined low temperature state (temperature state lower than the predetermined temperature state) is set at −10 ° C. to 20 ° C. However, this setting can be changed depending on the characteristics of the hydrogen storage alloy used, and is not limited to the above-mentioned temperature state. In addition, the upper limit of the temperature in the predetermined high temperature state can be naturally changed depending on what is used as the external load.

As will be described later, as the hydrogen storage alloy on the side of the main hydrogen storage tank 12 that releases hydrogen when heated to a predetermined high temperature state, for example, a Ti—Fe alloy, T
i-Mn-based alloys, La-based alloys, Mm-based alloys, and V-based alloys can be used. Of course, it is not limited to these alloys. On the other hand, in a low temperature state (−10 ° C. to 20 ° C.)
As a hydrogen storage alloy on the side of the secondary hydrogen storage tank 14 capable of generating a plateau pressure of 0.1 MPa at
Ti-Mn alloys such as 0.9Zr 0.1Mn 1.7, T
i-Cr alloys, La alloys, Mn alloys, Ti alloys
Cr, Zr, and base alloys such as Fe-based alloys
By adding additives such as V, Ni, Fe, Ca, and Al, it is possible to use a material having improved characteristics at low temperatures.
Of course, it is not limited to these alloys and additives.

The main hydrogen storage tank 12 is provided with a thermometer 32 for detecting the temperature of the internal hydrogen storage alloy and a pressure gauge 22 for detecting the internal hydrogen pressure. Similarly, the secondary hydrogen storage tank 14 is also provided with a thermometer 34 for detecting the temperature of the internal hydrogen storage alloy and a pressure gauge 24 for detecting the internal hydrogen pressure. Hydrogen from the main hydrogen storage tank 12 is supplied to the fuel cell 16 via a supply pipe 52. The supply pipe 52 is provided with a valve 44 for opening and closing the supply pipe 52. Further, hydrogen from the secondary hydrogen storage tank 14 is supplied to the fuel cell 16 via the supply pipe 54.
The supply pipe 54 is provided with a valve 42 for opening and closing the supply pipe 54. The supply pipe 52 and the supply pipe 54
A switching valve 46 is provided at the connection point between the main hydrogen storage tank 12 and the sub-hydrogen storage tank 14 by the valve 46. And
Between the main hydrogen storage tank 12 and the sub-hydrogen storage tank 14, a supply pipe 56 for communicating the two is provided.
The main hydrogen storage tank 12
The communication and separation of the secondary hydrogen storage tank 14 are performed. The valves 40, 42, 44, 46 described above
Is controlled by a control circuit 10. The control circuit 10 includes the main hydrogen storage tank 1 described above.
Based on the temperatures and pressures measured by the thermometers 32 and 34 and the pressure gauges 22 and 24 of the second and auxiliary hydrogen storage tanks 14, the opening and closing of the valves 40, 42, 44 and 46 are controlled.

The hydrogen gas supply device is used when hydrogen cannot be discharged from the main hydrogen storage tank 12 (when no heat is generated in the fuel cell 16 at the time of starting, or when the main hydrogen storage tank 12
Is not sufficiently warmed and the inside hydrogen pressure is not sufficiently high, for example). First, hydrogen is supplied from the auxiliary hydrogen storage tank 14 to the fuel cell 16 side. Then, the main hydrogen storage tank 12 is heated by the heat generated after the fuel cell 16 is activated by the hydrogen from the secondary hydrogen storage tank 14. Then, while supplying hydrogen from the main hydrogen storage tank 12 to the fuel cell 16 side, hydrogen from the main hydrogen storage tank 12 is sent to the sub-hydrogen storage tank 14 side,
It is stored in the auxiliary hydrogen storage tank 14.

This series of operations will be described in more detail with reference to the graph of FIG. 2 and the flowchart of FIG. In FIG. 2A, the horizontal axis represents the elapsed time, and the vertical axis represents the temperature (° C.) of the secondary hydrogen storage tank 14 and the main hydrogen storage tank 12.
2 (B) shows a graph of elapsed time and pressure (MPa), and FIG. 2 (C) shows a graph of hydrogen supply amount (L / min). Here, when the fuel cell 16 is started (time t0 in FIG. 2), the control circuit 10 determines that the temperature measured by the thermometer 32 of the main hydrogen storage tank 12 shown in FIG. It is determined whether the pressure measured by the pressure gauge 22 is 0.12 MPa or more (S12 in FIG. 3). When the pressure of the main hydrogen storage tank 12 is currently 0.12 MPa or more, for example, the vehicle is temporarily stopped, but the main hydrogen storage tank 12 has not been cooled because the stop has not been performed for a long time and the main hydrogen storage tank 12 has not been cooled. If the hydrogen pressure is sufficient in the tank 12 (S12
s) Go to step 28, close the valve 44 and open the valve 42, supply hydrogen from the main hydrogen storage tank 12 side to the fuel cell 16 via the supply pipe 52, and immediately start the steady operation. .

On the other hand, when the temperature of the main hydrogen storage tank 12 is 10
If the temperature is equal to or lower than ° C or the pressure is less than 0.12 MPa (No in S12), the process proceeds to step 14, where the valve 42 on the main hydrogen storage tank 12 is closed and the valve 44 on the sub hydrogen storage tank 14 is opened. And the secondary hydrogen storage tank 1
4 supplies hydrogen to the fuel cell 16 via a supply pipe 54. In the present embodiment, whether or not hydrogen can be discharged from the main hydrogen storage tank 12 is determined based on both the temperature and the pressure of the main hydrogen storage tank 12. However, either the temperature or the pressure is determined. The above determination may be made. At this time, the switching valve 46 is switched,
The hydrogen from the supply pipe 54 is passed to the fuel cell 16. As a result, the fuel cell 16 is started (time t0 in FIG. 2), the waste heat temperature (cooling water temperature) of the fuel cell 16 rises as shown in FIG. And the temperature of the main hydrogen storage tank 12 rises. Then, as the temperature increases, the pressure in the main hydrogen storage tank 12 increases (see FIG. 2B).

On the other hand, on the other hand, on the side of the sub-hydrogen storage tank 14, the internal pressure is gradually decreased by the supply of hydrogen (see FIG. 2B), and the hydrogen is absorbed from the internal hydrogen storage alloy. The temperature decreases due to the endothermic reaction when released. FIG. 2C shows the amount of hydrogen supply from the sub-hydrogen storage tank 14 from the time t0.

The control circuit 10 continues to determine whether the pressure in the main hydrogen storage tank 12 has become 0.12 MPa or more (S16). Here, when the pressure of the main hydrogen storage tank 12 is less than 0.12 MPa (S16: No), the process returns to step 14, and the supply of hydrogen from the sub hydrogen storage tank 14 is continued. On the other hand, when the pressure of the main hydrogen storage tank 12 becomes 0.12 MPa or more due to the heat supply from the fuel cell 16 (Yes in S16), the process proceeds to step 18, where the pressure in the sub-hydrogen storage tank 14 becomes 0.1 due to the release of hydrogen. 12MPa
It is determined whether the temperature has decreased to the following (S18). Here, while the pressure does not decrease to 0.12 MPa (S18 is N
o), returning to step 14 to continue supplying hydrogen from the secondary hydrogen storage tank 14;

On the other hand, when the pressure in the secondary hydrogen storage tank 14 drops to 0.12 MPa or less at time t1 in FIG. 2 (Yes in S18), the process proceeds to step 20, and the valve 44 on the secondary hydrogen storage tank 14 side is closed. At the same time, the valve 42 is opened and the supply pipe 52 is opened from the main hydrogen storage tank 12 side.
The hydrogen is supplied to the fuel cell 16 side via the. This S18
By judging the pressure of the secondary hydrogen storage tank 14 according to the above, it is confirmed whether or not the hydrogen inside has been sufficiently used. For this reason, it is possible to effectively use the hydrogen in the secondary hydrogen storage tank 14. At this time, the switching valve 46 is switched so that hydrogen from the supply pipe 52 is passed. When the supply of hydrogen from the main hydrogen storage tank 12 is started, the valve 40 is opened to open the main hydrogen storage tank 12.
The hydrogen on the side is supplied to the sub-hydrogen storage tank 14, and the filling of the sub-hydrogen storage tank 14 is started (S22).

As described above, the internal pressure of the secondary hydrogen storage tank 14 is reduced to 0.12 MPa or less due to the release of hydrogen (see FIG. 2 (B)), and the temperature is lowered by -10 ° by the endothermic reaction. C (Fig. 2 (A)
reference). On the other hand, the pressure in the main hydrogen storage tank 12 heated by the waste heat from the fuel cell 16 is increasing. Therefore, by opening the valve 40, the main hydrogen storage tank 12
Is supplied to the side of the sub-hydrogen storage tank 14 and stored in the low-temperature hydrogen storage alloy in the sub-hydrogen storage tank 14. By filling the secondary hydrogen storage tank 14 with hydrogen,
From time t1, the temperature and pressure in the secondary hydrogen storage tank 14 increase.

The control circuit 10 monitors the pressure in the main hydrogen storage tank 12 and the pressure in the sub-hydrogen storage tank 14 and determines whether the two pressures are equal (S24). Here, while the pressure on the side of the secondary hydrogen storage tank 14 is low (S24
No), the process returns to step 22, and the secondary hydrogen storage tank 14
Continue filling hydrogen into the reactor. Then, the time t shown in FIG.
When the pressures of the two become equal at 2 (Yes at S24),
The valve 40 is closed to complete the filling of the secondary hydrogen storage tank 14 with hydrogen (S26). As described above, the valve 44 is closed and the valve 42 is opened, and the supply of hydrogen from the main hydrogen storage tank 12 is continued (S28).

As described above, in the present embodiment, when the fuel cell 16 is started, the hydrogen in the sub-hydrogen storage tank 14 is released, but the supply of hydrogen from the main hydrogen storage tank 12 to the fuel cell side is performed. When starting, the main hydrogen storage tank 12
The hydrogen is supplied to the sub-hydrogen storage tank 14 from the sub-hydrogen storage tank 14 and stored in the sub-hydrogen storage tank 14. Therefore, it is possible to repeat the start of the fuel cell using the small hydrogen storage tank 14 having a small capacity, that is, a capacity capable of starting the fuel cell 16 once.

The capacity of the sub-hydrogen storage tank 14 that can start the fuel cell 16 once depends on the time required for the main hydrogen storage tank 12 to reach a temperature and pressure at which hydrogen can be released, and the flow rate of hydrogen gas released during that time. Is determined by This depends on the ambient temperature, the capacity of the main hydrogen storage tank, and the performance of the heat exchanger. Furthermore, since the temperature of the low-temperature operating hydrogen storage alloy stored in the sub-hydrogen storage tank 14 decreases while releasing hydrogen, not all of the stored hydrogen can be released. In particular, the amount of hydrogen released from the low-temperature operation hydrogen storage alloy is affected by the temperature drop due to the endothermic reaction, and this also depends on the environmental temperature and the characteristics of the alloy. In the present embodiment, the secondary hydrogen storage tank 1
4 and the material of the low-temperature hydrogen storage alloy are determined.

On the other hand, as described above, in the conventional hydrogen gas supply device including the main hydrogen storage tank (running hydrogen storage tank) and the auxiliary hydrogen storage tank (starting hydrogen storage tank), an external hydrogen filling device is used. The main hydrogen storage tank and the sub-hydrogen storage tank were simultaneously performed when hydrogen was charged, and thereafter, the hydrogen was supplied from the sub-hydrogen storage tank side every time the fuel cell or the like was started. For this reason, it was unavoidable to enlarge the secondary hydrogen storage tank so that a large amount of hydrogen could be stored. That is, in order to be able to start the fuel cell five times with one hydrogen filling, the capacity of the sub-hydrogen storage tank according to the present embodiment is required to be approximately five times as large.

Here, the secondary hydrogen storage tank has a capacity of 0.1 M which can start the fuel cell even at a low temperature (for example, -10 ° C.).
When Pa can be generated, the pressure rises to a very high value at the allowable upper limit temperature (for example, 60 ° C.) of the hydrogen gas supply device. For this reason, in order to increase the pressure resistance of the sub-hydrogen storage tank, it is necessary to make the structure more robust than the main hydrogen storage tank, and the device per unit capacity becomes larger and the weight increases. Therefore, a secondary hydrogen storage tank (starting tank) having a capacity five times that of the present embodiment is directly linked to energy loss when mounted on an electric vehicle.

Further, in the conventional hydrogen gas supply device,
The hydrogen in the starting tank is not always used during normal running. For example, even in a hydrogen gas supply device having a starting tank set to be able to start five times, it is usually used only once or twice. Therefore, the remaining four to three times of hydrogen may not be used while being stored in the starting tank. Therefore, in the hydrogen gas supply device of the related art, the vehicle is driven by storing unused hydrogen in the hydrogen storage alloy, and there is a possibility that the running efficiency of the electric vehicle is reduced. On the other hand, in the hydrogen gas supply device of the present embodiment, since the unused hydrogen is not stored in the auxiliary hydrogen storage tank 14 side, the electric vehicle can be efficiently driven.

Further, in the hydrogen gas supply device and the hydrogen gas supply method of the present embodiment, since a heating device is not particularly arranged in the secondary hydrogen storage tank 14, the device can be configured simply and lightly.

Next, the management of the main hydrogen storage tank 12 and the sub-hydrogen storage tank 14 in the normal state by the hydrogen gas supply device of the first embodiment will be described with reference to the flowchart of FIG. The control circuit 10 always operates the secondary hydrogen storage tank 14 regardless of whether the fuel cell 16 is operating.
The pressure inside is monitored. Here, the secondary hydrogen storage tank 1
When the pressure in the fuel tank 4 is less than a preset value (for example, 1 MPa) (No in S30), the supply pipe 56 that connects the main hydrogen storage tank 12 and the sub hydrogen storage tank 14 shown in FIG.
Is closed (S34). On the other hand, when the environmental temperature rises to a very high temperature and the pressure in the secondary hydrogen storage tank 14 exceeds a preset 1 MPa (S30: Yes), the valve 40 of the supply pipe 56 is opened (S32).
The hydrogen in the secondary hydrogen storage tank 14 is
Side, and is adsorbed by the high-temperature hydrogen storage alloy in the main hydrogen storage tank 12 to maintain the pressure in the sub-hydrogen storage tank 14 at 1 MPa or less.

In this embodiment, the control circuit monitors the pressure in the secondary hydrogen storage tank 14 to control the valve 40. However, instead of or together with this control, the control circuit and the secondary hydrogen storage tank 14 A relief valve is provided between the main hydrogen storage tank 12 and, for example, when the pressure in the sub-hydrogen storage tank 14 reaches 1.1 MPa, hydrogen from the sub-hydrogen storage tank 14 is released to the main hydrogen storage tank 12. Alternatively, the pressure in the secondary hydrogen storage tank 14 may be reduced.

As described above, when the temperature of the secondary hydrogen storage tank 14 containing the hydrogen storage alloy that generates a predetermined pressure even at a low temperature rises to a normal temperature or higher, the internal pressure can rise to a high value. For this reason, the starting tank of the prior art requires a very robust configuration and has to be enlarged in synergy with the relatively large capacity required as described above. In contrast, in the present embodiment, the secondary hydrogen storage tank 1
4 may be configured to withstand a predetermined value, so that it is possible to reduce the size.

[0041]

As described above, according to the first and fourth aspects of the present invention, the hydrogen storage tank is heated at the start to supply hydrogen from the secondary hydrogen storage tank to the fuel cell (external load) at the start. Hydrogen can be supplied to the fuel cell without the need. Further, when the supply of hydrogen from the main hydrogen storage tank to the fuel cell side is started, the hydrogen is supplied from the main hydrogen storage tank to the sub-hydrogen storage tank from which hydrogen was released when the fuel cell was started. Since hydrogen is stored in the tank, it is possible to repeat the start of the fuel cell using a small-capacity sub-hydrogen storage tank that is minimum necessary for starting the fuel cell.

According to the second aspect of the present invention, since the heat from the fuel cell is not supplied to the secondary hydrogen storage tank, the configuration can be simplified.

According to the third or sixth aspect of the present invention, when the pressure in the sub-hydrogen storage tank exceeds a predetermined value, hydrogen is released from the sub-hydrogen storage tank to the main hydrogen storage tank. The pressure in the sub-hydrogen storage tank where the hydrogen pressure can be generated can be kept within a certain level, which is safe.

According to the fifth aspect of the present invention, after the storage of hydrogen in the secondary hydrogen storage tank is started, when the pressure in the secondary hydrogen storage tank and the pressure in the main hydrogen storage tank become substantially equal, The storage of hydrogen in the secondary hydrogen storage tank is completed.
For this reason, hydrogen can be stored in the sub hydrogen storage tank to the maximum pressure that can be realized using the hydrogen pressure of the main hydrogen storage tank.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a hydrogen gas supply device according to a first embodiment of the present invention.

FIG. 2A is a graph showing the temperature and elapsed time of a main hydrogen storage tank and a sub-hydrogen storage tank.
FIG. 2B is a graph showing pressure and elapsed time, and FIG.
(C) is a graph showing a hydrogen supply amount and an elapsed time.

FIG. 3 is a flowchart showing a process when the fuel cell is started in the hydrogen gas supply device according to the first embodiment of the present invention.

FIG. 4 is a flowchart showing a normal process in the hydrogen gas supply device according to the first embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10 control circuit (supply path switching means) 12 main hydrogen storage tank 14 sub hydrogen storage tank 16 fuel cell 18 heat exchanger (heat supply device) 22 pressure gauge (main pressure detection device) 24 pressure gauge (sub pressure detection device) 32, 34 thermometer 40, 42, 44, 46 valve 52 supply pipe (first supply path) 54 supply pipe (second supply path) 56 supply pipe (third supply path)

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masafumi Kobayashi F-term (reference) 5-3-0-6 Imura Japan Co., Ltd. 2-3-6 Shimonopporo Techno Park, Atsubetsu-ku, Sapporo, Hokkaido 5H027 AA06 BA14 CC06 KK01 MM01 MM08 MM09

Claims (8)

[Claims] 1. A main hydrogen storage tank containing a high-temperature hydrogen storage alloy that releases hydrogen at a predetermined high temperature, and a low-temperature hydrogen storage alloy that can release hydrogen at a temperature lower than the predetermined high temperature. A secondary hydrogen storage tank to be accommodated; a first supply path for supplying hydrogen from the main hydrogen storage tank to an external load; a second supply path for supplying hydrogen from the secondary hydrogen storage tank to an external load; A third supply path for supplying hydrogen from the hydrogen storage tank to the sub-hydrogen storage tank, a heat supply device for supplying heat generated by the external load to the main hydrogen storage tank, and a hydrogen pressure of the main hydrogen storage tank When the hydrogen pressure in the main hydrogen storage tank detected by the main pressure detection device is low, removing hydrogen from the sub-hydrogen storage tank through the second supply path. Supply to a load, and when the hydrogen pressure in the main hydrogen storage tank detected by the main pressure detection device increases, the external load of hydrogen from the main hydrogen storage tank through the first supply path Supply path switching means for starting supply of hydrogen to the secondary hydrogen storage tank via the third supply path and storing hydrogen in the secondary hydrogen storage tank. Gas supply device. 2. The hydrogen gas supply device according to claim 1, wherein heat from the external load is not supplied to the secondary hydrogen storage tank. 3. A sub-pressure detecting device for detecting a pressure in the sub-hydrogen storage tank, wherein the supply path switching means sets the pressure in the sub-hydrogen storage tank detected by the sub-pressure detecting device to a predetermined value. 3. The hydrogen gas supply device according to claim 1, wherein, when the hydrogen gas is exceeded, hydrogen is released from the secondary hydrogen storage tank to the main hydrogen storage tank via the third supply path. 4. 4. A main hydrogen storage tank for storing a high-temperature hydrogen storage alloy that releases hydrogen by heat supplied from an external load, and a sub-hydrogen storage tank for storing a low-temperature hydrogen storage alloy that can release hydrogen at room temperature. A hydrogen gas supply method for supplying hydrogen from the main hydrogen storage tank and the sub-hydrogen storage tank to an external load, wherein the main hydrogen at the time of startup when heat is not supplied from the external load to the main hydrogen storage tank When the hydrogen pressure in the storage tank is low, hydrogen is supplied from the sub-hydrogen storage tank to the external load, heat is supplied from the external load to the main hydrogen storage tank, and the hydrogen pressure in the main hydrogen storage tank increases. At the same time, the supply of hydrogen from the main hydrogen storage tank to the external load is started, and the supply of hydrogen from the main hydrogen storage tank to the sub-hydrogen storage tank is performed. Hydrogen gas supply wherein the to store hydrogen within. 5. After starting storage of hydrogen in the secondary hydrogen storage tank, when the pressure in the secondary hydrogen storage tank and the pressure in the main hydrogen storage tank become substantially equal, the secondary hydrogen The hydrogen gas supply method according to claim 4, wherein the storage of hydrogen in the storage tank is completed. 6. The method according to claim 4, wherein when the pressure in the secondary hydrogen storage tank exceeds a predetermined value, hydrogen is released from the secondary hydrogen storage tank to the main hydrogen storage tank. Hydrogen gas supply method. 7. The hydrogen gas supply device according to claim 1, wherein the external load is a fuel cell. 8. The method for supplying hydrogen gas according to claim 4, wherein the external load is a fuel cell.