Hydrogen generator

Abstract

It provides a stable supply of hydrogen gas when switching cartridges. [Solution] A hydrogen generator comprising a water supply device for supplying water to first and second cartridges, a first hydrogen supply valve for opening and closing a first hydrogen supply passage for supplying hydrogen gas from the first cartridge to a buffer tank, a second hydrogen supply valve for opening and closing a second hydrogen supply passage for supplying hydrogen gas from the second cartridge to the buffer tank, and a main hydrogen supply passage for supplying hydrogen gas from the buffer tank to the outside. When switching the hydrogen supply source from the first cartridge to the second cartridge, the control device performs a first process of supplying water to the second cartridge while stopping the water supply to the first cartridge and closing the second hydrogen supply valve, and a second process of opening the second hydrogen supply valve after the first process and supplying hydrogen gas from the second cartridge to the buffer tank.

Description

Technical Field

[0001] The technology disclosed in this specification relates to a hydrogen generator.

[0002] Hydrogen generators that generate hydrogen using a cartridge containing a substance that reacts with water to generate hydrogen gas are known. For example, Patent Document 1 discloses a hydrogen generator that uses a cartridge containing a substance (specifically, a catalyst) that reacts with water (specifically, an aqueous solution) to generate hydrogen gas. The cartridge is detachable from the hydrogen generator. The hydrogen generator generates hydrogen gas by supplying water into the cartridge and supplies the generated hydrogen gas to an external device (e.g., a fuel cell).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the hydrogen generator of Patent Document 1, since there is only one cartridge attachment part, the hydrogen generator cannot be used during the replacement of the cartridge. Therefore, the continuous operation time of the hydrogen generator of Patent Document 1 is short. In contrast, by providing a plurality of cartridge attachment parts in the hydrogen generator and switching the cartridges to be used, the continuous operation time of the hydrogen generator can be lengthened. In this specification, a technique for stably supplying hydrogen gas when switching the cartridge to be used in a hydrogen generator capable of attaching a plurality of cartridges is proposed.

Means for Solving the Problems

[0005] The first hydrogen generator disclosed herein includes a first mounting section and a second mounting section to which cartridges containing a substance that reacts with water to generate hydrogen gas are attached; a water supply device for supplying water to a first cartridge attached to the first mounting section and a second cartridge attached to the second mounting section; a buffer tank; a first hydrogen supply path for supplying hydrogen gas from the first cartridge to the buffer tank; a second hydrogen supply path for supplying hydrogen gas from the second cartridge to the buffer tank; a first hydrogen supply valve for opening and closing the first hydrogen supply path; a second hydrogen supply valve for opening and closing the second hydrogen supply path; a main hydrogen supply path for supplying hydrogen gas from the buffer tank to the outside; and a control device for controlling the water supply device, the first hydrogen supply valve, and the second hydrogen supply valve. When the hydrogen supply source is switched from the first cartridge to the second cartridge while water is being supplied to the first cartridge and the first hydrogen supply valve is open, thereby supplying hydrogen gas from the first cartridge to the buffer tank, the control device executes a first process and a second process. In the first process, the control device stops supplying water to the first cartridge and supplies water to the second cartridge with the second hydrogen supply valve closed. In the second process, after the first process, the control device opens the second hydrogen supply valve and supplies hydrogen gas from the second cartridge to the buffer tank.

[0006] Furthermore, the "water" in the above-mentioned "substance that reacts with water to generate hydrogen gas" may be pure water or an aqueous solution.

[0007] In the first hydrogen generator, when switching the hydrogen supply source from the first cartridge to the second cartridge, in the first process, water is supplied to the second cartridge with the second hydrogen supply valve closed. Hydrogen gas is generated in the second cartridge by the water supply. Because the second hydrogen supply valve is closed, the pressure inside the second cartridge increases due to the generation of hydrogen gas. Subsequently, in the second process, the second hydrogen supply valve is opened and hydrogen gas is supplied from the second cartridge to the buffer tank. Because the pressure inside the second cartridge is high, hydrogen gas can be supplied appropriately from the second cartridge to the buffer tank. In this way, the hydrogen supply source can be switched from the first cartridge to the second cartridge by performing the first and second processes. Also, in the first process, the water supply to the first cartridge is stopped and water is supplied to the second cartridge. Because the water supply to the first cartridge is stopped, the supply of hydrogen gas from the first cartridge to the buffer tank decreases or stops after the first process. However, even if the supply of hydrogen gas from the first cartridge to the buffer tank decreases, hydrogen gas is supplied from the buffer tank to the main hydrogen supply line due to the pressure inside the buffer tank. Therefore, this hydrogen generator can stably supply hydrogen gas even during switching operations.

[0008] The second hydrogen generator disclosed herein includes a first mounting section and a second mounting section to which a cartridge containing a substance that reacts with water to generate hydrogen gas is attached; a first water supply device for supplying water to a first cartridge attached to the first mounting section; a second water supply device for supplying water to a second cartridge attached to the second mounting section; a main hydrogen supply passage for supplying hydrogen gas to the outside; a first hydrogen supply passage for supplying hydrogen gas from the first cartridge to the main hydrogen supply passage; a second hydrogen supply passage for supplying hydrogen gas from the second cartridge to the main hydrogen supply passage; a first hydrogen supply valve for opening and closing the first hydrogen supply passage; a second hydrogen supply valve for opening and closing the second hydrogen supply passage; and a control device for controlling the first water supply device, the second water supply device, the first hydrogen supply valve, and the second hydrogen supply valve. When switching the hydrogen supply source from the first cartridge to the second cartridge while water is being supplied to the first cartridge and the first hydrogen supply valve is open, thereby supplying hydrogen gas from the first cartridge to the main hydrogen supply line, the control device performs a first process and a second process. In the first process, the control device supplies water to the second cartridge while maintaining the state of supplying water to the first cartridge and keeping the first hydrogen supply valve open, and closing the second hydrogen supply valve. In the second process, after the first process, the control device opens the second hydrogen supply valve to supply hydrogen gas from the second cartridge to the main hydrogen supply line and closes the first hydrogen supply valve.

[0009] Furthermore, the "water" in the above-mentioned "substance that reacts with water to generate hydrogen gas" may be pure water or an aqueous solution.

[0010] In the second hydrogen generator, when switching the hydrogen supply source from the first cartridge to the second cartridge, in the first process, water is supplied to the second cartridge with the second hydrogen supply valve closed. Hydrogen gas is generated in the second cartridge by the water supply. Because the second hydrogen supply valve is closed, the pressure inside the second cartridge increases due to the generation of hydrogen gas. Subsequently, in the second process, the second hydrogen supply valve is opened to supply hydrogen gas from the second cartridge to the main hydrogen supply line. Because the pressure inside the second cartridge is high, hydrogen gas can be supplied appropriately from the second cartridge to the main hydrogen supply line. Also, in the second process, the first hydrogen supply valve is closed to stop the supply of hydrogen gas from the first cartridge to the main hydrogen supply line. In this way, by performing the first and second processes, the hydrogen supply source can be switched from the first cartridge to the second cartridge. In addition, in the first process, water is supplied to the first cartridge and the state in which the first hydrogen supply valve is open is maintained. That is, in the first process, the state in which hydrogen gas is supplied from the first cartridge to the main hydrogen supply line is maintained. Therefore, this hydrogen generator can stably supply hydrogen gas even during switching operations. [Brief explanation of the drawing]

[0011] [Figure 1] Perspective view of the hydrogen generator. [Figure 2] A diagram showing the paths of hydrogen gas and water in the hydrogen generator of Example 1. [Figure 3] A diagram showing the paths of hydrogen gas and water at each stage of the hydrogen generator in Example 1. [Figure 4] A flowchart illustrating the switching process in Example 1. [Figure 5] A diagram showing the paths of hydrogen gas and water in the hydrogen generator of Example 2. [Figure 6] A diagram showing the paths of hydrogen gas and water at each stage of the hydrogen generator in Example 2. [Figure 7] A flowchart illustrating the switching process in Example 2. [Modes for carrying out the invention]

[0012] In the first hydrogen generator, the control device may perform the first process while maintaining the first hydrogen supply valve in an open state, and then close the first hydrogen supply valve after the first process.

[0013] With this configuration, hydrogen gas can be supplied to the buffer tank from the first cartridge during the execution of the first process. Therefore, this hydrogen generator can supply hydrogen gas more stably during the switching operation.

[0014] In the first hydrogen generator, the control device may perform a process before the first process to increase the amount of water supplied to the first cartridge and raise the pressure inside the first cartridge.

[0015] This configuration allows for a more stable supply of hydrogen gas from the first cartridge to the buffer tank during the execution of the first and second processes.

[0016] The first hydrogen generator may further include a purge valve that opens and closes a flow path that opens the second cartridge to the outside air. In the first process, the control device may open the purge valve to purge the second cartridge, and after the purging, close the purge valve to increase the pressure inside the second cartridge.

[0017] Before use, the second cartridge is filled with a different filling gas (e.g., an inert gas) than hydrogen gas. With this hydrogen generator, the filling gas can be discharged from the second cartridge to the outside by purging, thus preventing the filling gas from being supplied to the buffer tank.

[0018] The second hydrogen generator may further include a purge valve that opens and closes a flow path for opening the second cartridge to the outside air. In the first process, the control device may open the purge valve to purge the second cartridge, and after the purge, close the purge valve to increase the pressure inside the second cartridge.

[0019] According to this hydrogen generator, the filling gas can be discharged from the second cartridge to the outside by purging, so it is possible to prevent the filling gas from being supplied to the main hydrogen supply path.

Example

[0020] As shown in FIG. 1, the hydrogen generator 10 of Example 1 has a first slot hole 11 and a second slot hole 12 provided on the side surface. By inserting the cartridge C into each of the slot holes 11 and 12, the cartridge C can be attached to the hydrogen generator 10. The cartridge C is a kind of reaction vessel and contains a hydrogen generating agent inside. The hydrogen generating agent is a substance that generates hydrogen gas (that is, H2) when reacting with water, and in this example, it is sodium borohydride. The cartridge C is detachable with respect to the slot holes 11 and 12. Hereinafter, the cartridge attached to the first slot hole 11 is referred to as cartridge C1, and the cartridge attached to the second slot hole 12 is referred to as cartridge C2.

[0021] FIG. 2 is a path diagram showing the paths of hydrogen gas and water inside the hydrogen generator 10. In FIG. 2, the solid line path is the hydrogen gas path, and the broken line path is the water path.

[0022] The hydrogen generator 10 has a water tank 56 and a water supply pipe 54. Water (more specifically, pure water) is stored in the water tank 56. The upstream end of the water supply pipe 54 is connected to the water tank 56. The downstream part of the water supply pipe 54 branches into two branch pipes 54a and 54b. When cartridge C1 is installed in the hydrogen generator 10, the downstream end of branch pipe 54a is connected to cartridge C1. When cartridge C2 is installed in the hydrogen generator 10, the downstream end of branch pipe 54b is connected to cartridge C2. A pump 50 is provided in the upstream part of the water supply pipe 54 (i.e., the unbranched part). The pump 50 sends the water in the water supply pipe 54 downstream. Branch pipe 54a is provided with a valve VW1 that opens and closes branch pipe 54a. Branch pipe 54b is provided with a valve VW2 that opens and closes branch pipe 54b. The water supply pipe 54 supplies water from the water tank 56 to cartridges C1 and C2. When water is injected into cartridge C1 from the water supply pipe 54, the hydrogen generating agent and water react inside cartridge C1 to generate hydrogen gas. When water is injected into cartridge C2 from the water supply pipe 54, the hydrogen generating agent and water react inside cartridge C2 to generate hydrogen gas.

[0023] The hydrogen generator 10 includes a first hydrogen supply pipe 21, a second hydrogen supply pipe 22, and a buffer tank 20. When cartridge C1 is installed in the hydrogen generator 10, the upstream end of the first hydrogen supply pipe 21 is connected to cartridge C1. The downstream end of the first hydrogen supply pipe 21 is connected to the buffer tank 20. When cartridge C2 is installed in the hydrogen generator 10, the upstream end of the second hydrogen supply pipe 22 is connected to cartridge C2. The downstream end of the second hydrogen supply pipe 22 is connected to the buffer tank 20. In Figure 1, the downstream sections of the first hydrogen supply pipe 21 and the second hydrogen supply pipe 22 are shared, but the first hydrogen supply pipe 21 and the second hydrogen supply pipe 22 may each be independently connected to the buffer tank 20. The first hydrogen supply pipe 21 supplies hydrogen gas from cartridge C1 to the buffer tank 20. The second hydrogen supply pipe 22 supplies hydrogen gas from cartridge C2 to the buffer tank 20.

[0024] A valve VH1 for opening and closing the first hydrogen supply pipe 21 is provided in the upstream portion of the first hydrogen supply pipe 21 (i.e., the portion independent from the second hydrogen supply pipe 22). A pressure sensor PS1 is provided in the first hydrogen supply pipe 21 upstream of valve VH1. The pressure sensor PS1 detects the pressure P1 inside cartridge C1. One end of a purge pipe 23 is connected to the first hydrogen supply pipe 21 upstream of valve VH1. The other end of the purge pipe 23 is connected to the outside of the hydrogen generator 10 via a check valve. The check valve of the purge pipe 23 allows gas to flow out of the purge pipe 23 to the outside, while preventing gas from flowing into the purge pipe 23 from the outside. When the check valve opens, cartridge C1 is exposed to the outside air. A purge valve VO1 for opening and closing the purge pipe 23 is provided in the purge pipe 23.

[0025] Upstream of the second hydrogen supply pipe 22 (i.e., the portion independent from the first hydrogen supply pipe 21), a valve VH2 is provided to open and close the second hydrogen supply pipe 22. Upstream of valve VH2, a pressure sensor PS2 is provided in the second hydrogen supply pipe 22. The pressure sensor PS2 detects the pressure P2 inside cartridge C2. One end of a purge pipe 24 is connected to the second hydrogen supply pipe 22 upstream of valve VH2. The other end of the purge pipe 24 is connected to the outside of the hydrogen generator 10 via a check valve. The check valve of the purge pipe 24 allows gas to flow out of the purge pipe 24 to the outside, while preventing gas from flowing into the purge pipe 24 from the outside. When the check valve opens, cartridge C2 is opened to the outside air. The purge pipe 24 is provided with a purge valve VO2 to open and close the purge pipe 24.

[0026] Hydrogen gas is supplied to the buffer tank 20 from cartridges C1 and C2. The buffer tank 20 temporarily stores the hydrogen gas supplied from cartridges C1 and C2. The upstream end of the main hydrogen supply pipe 26 is connected to the buffer tank 20. The downstream end of the main hydrogen supply pipe 26 is connected to an external device 99 (for example, a fuel cell system) installed outside the hydrogen generator 10. The hydrogen gas in the buffer tank 20 is supplied to the external device 99 via the main hydrogen supply pipe 26.

[0027] The main hydrogen supply pipe 26 is equipped with, in order from upstream, a condenser 30, a gas-liquid separator 32, a regulator 34, and a main valve 36. The main valve 36 opens and closes the main hydrogen supply pipe 26. When the main valve 36 is open, hydrogen gas is supplied from the buffer tank 20 to the external device 99 via the main hydrogen supply pipe 26.

[0028] The condenser 30 cools the hydrogen gas in the main hydrogen supply pipe 26 by heat exchange with the outside air. The hydrogen gas generated in cartridges C1 and C2 contains water vapor. The condenser 30 condenses the water vapor in the hydrogen gas by cooling the hydrogen gas in the main hydrogen supply pipe 26.

[0029] Hydrogen gas and liquid water that have passed through the condenser 30 flow into the gas-liquid separator 32. The gas-liquid separator 32 separates water from the hydrogen gas. The gas-liquid separator 32 is connected to the water tank 56 by a drain pipe 58. The water separated from the hydrogen gas in the gas-liquid separator 32 is returned to the water tank 56 via the drain pipe 58.

[0030] The hydrogen gas separated from the water in the gas-liquid separator 32 flows downstream through the main hydrogen supply pipe 26. The regulator 34 adjusts the pressure of the hydrogen gas supplied to the external device 99.

[0031] The hydrogen generator 10 has a control device 90. The control device 90 controls valves VH1, VW1, VO1, VH2, VW2, VO2, pump 50, and main valve 36. The control device 90 also receives the detected values ​​from pressure sensors PS1 and PS2.

[0032] Next, the operation of supplying hydrogen gas to the external device 99 will be described. When supplying hydrogen gas to the external device 99, the main valve 36 is controlled to be in the open state. In the following description of the operation, the main valve 36 will be assumed to be open. The hydrogen generator 10 can perform a first operation in which hydrogen gas is generated in cartridge C1, and a second operation in which hydrogen gas is generated in cartridge C2.

[0033] In the first operation, the control device 90 controls the valves VH1, VW1, VO1, VH2, VW2, VO2 and the pump 50 as follows. Valve VH1: Open Valve VW1: Open Valve VO1: Closed Valve VH2: Closed Valve VW2: Closed Valve VO2: Closed Pump 50: Operation

[0034] Figure 3(a) shows the first operation. In the first operation, valve VW2 is closed and valve VW1 is open, so water delivered by pump 50 is injected into cartridge C1. As a result, hydrogen gas is generated in cartridge C1. Since valve VH1 is open, hydrogen gas is supplied from cartridge C1 to buffer tank 20. The hydrogen gas in buffer tank 20 flows to the main hydrogen supply pipe 26 and is supplied to the external device 99. Also in the first operation, the control device 90 provides feedback control to pump 50 based on the pressure P1 in cartridge C1 (i.e., the value detected by pressure sensor PS1). The control device 90 adjusts the amount of water supplied to cartridge C1 by operating pump 50 intermittently, controlling the pressure P1 in cartridge C1 to approximately 190 kPa. As a result, the pressure of the hydrogen gas in buffer tank 20 also becomes high.

[0035] Next, we will explain the switching process that transitions from the first operation, in which hydrogen gas is generated in cartridge C1, to the second operation, in which hydrogen gas is generated in cartridge C2. The flowchart in Figure 4 shows the switching process. The control device 90 executes the process in Figure 4 when a cartridge switch is necessary, such as when the usage time of cartridge C1 exceeds a reference value. At the timing of the start of the switch in Figure 4, the control device 90 is executing the first operation (i.e., Figure 3(a)).

[0036] In step S2, the control device 90 operates the pump 50 continuously to increase the amount of water supplied to the cartridge C1. This causes the pressure P1 inside the cartridge C1 to rise. In step S4, the control device 90 determines whether the pressure P1 inside the cartridge C1 exceeds 210 kPa. The control device 90 repeats steps S2 and S4 until the pressure P1 exceeds 210 kPa.

[0037] When the pressure P1 exceeds 210 kPa, the control device 90 temporarily stops the pump 50 in step S6. Next, in step S8, the control device 90 controls the valve as follows. Valve VW1: Closed Valve VW2: Open Valve VO2: Open The status of the other valves will not be changed. Next, in step S10, the control device 90 activates the pump 50.

[0038] Figure 3(b) shows the state of each part in step S10. Since valve VW1 is closed, the water supply to cartridge C1 is stopped. Also, since valve VW2 is open, water supplied by pump 50 is injected into cartridge C2. As a result, hydrogen gas is generated in cartridge C2. Since valve VH2 is closed and purge valve VO2 is open, the gas in cartridge C2 is released to the outside through purge valve VO2. Before use, cartridge C2 is sealed with an inert gas (for example, nitrogen gas). As shown in Figure 3(b), purging cartridge C2 releases the inert gas inside cartridge C2 to the outside of the hydrogen generator 10. This prevents the inert gas from flowing into the buffer tank 20 in a later step.

[0039] Furthermore, as shown in Figure 3(b), since the pressure in the buffer tank 20 is high, hydrogen gas flows from the buffer tank 20 to the main hydrogen supply pipe 26 even in step S10. In this way, the supply of hydrogen gas to the main hydrogen supply pipe 26 continues even in step S10. Also, as shown in Figure 3(b), since valve VH1 is open in step S10, hydrogen gas flows from cartridge C1 to the buffer tank 20. In particular, since the pressure in cartridge C1 has been raised in advance in steps S2 and S4, hydrogen gas flows from cartridge C1 to the buffer tank 20 even when the water injection into cartridge C1 is stopped. This suppresses the pressure drop in the buffer tank 20.

[0040] In step S10, the control device 90 performs a purging operation of cartridge C2 for a certain period of time, and then performs the pressure increase operation in step S12. In step S12, the control device 90 closes the purge valve VO2. The state of the other valves remains unchanged. Figure 3(c) shows the state of each part in step S12. When the purge valve VO2 is closed, the release of gas from cartridge C2 to the outside stops. As a result, the pressure P2 inside cartridge C2 rises as hydrogen gas is generated inside cartridge C2. In step S14, the control device 90 determines whether the pressure P2 inside cartridge C2 exceeds 190 kPa. The control device 90 repeats steps S12 and S14 until the pressure P2 exceeds 190 kPa.

[0041] As shown in Figure 3(c), hydrogen gas flows from the buffer tank 20 to the main hydrogen supply pipe 26 even while steps S12 and S14 are being executed. In this way, the supply of hydrogen gas to the main hydrogen supply pipe 26 continues even during steps S12 and S14. Also, as shown in Figure 3(c), hydrogen gas flows from cartridge C1 to the buffer tank 20 even while steps S12 and S14 are being executed. This suppresses a pressure drop in the buffer tank 20.

[0042] When the pressure P2 exceeds 190 kPa, the control device 90 closes valve VH1 in step S16 and opens valve VH2 in step S18. As shown in Figure 3(d), the closing of valve VH1 stops the supply of hydrogen gas from cartridge C1 to buffer tank 20, and the opening of valve VH2 starts the supply of hydrogen gas from cartridge C2 to buffer tank 20. Since the pressure in cartridge C2 has risen to an appropriate value in steps S12 and S14, hydrogen gas is properly supplied from cartridge C2 to buffer tank 20. In this way, by executing steps S16 and S18, the supply of hydrogen gas from cartridge C1 is stopped, and instead, the supply of hydrogen gas from cartridge C2 is started. This completes the switchover from the first operation in which hydrogen gas is generated in cartridge C1 to the second operation in which hydrogen gas is generated in cartridge C2. In the second operation after the switchover is complete, the control device 90 intermittently operates pump 50 so that the pressure P2 in cartridge C2 reaches an appropriate value.

[0043] As described above, since the hydrogen generator 10 of Example 1 has a buffer tank 20, the supply of hydrogen gas to the main hydrogen supply pipe 26 is maintained by the pressure in the buffer tank 20 during the cartridge switching process. Therefore, the switching process can be performed without interrupting the supply of hydrogen gas to the external device 99.

[0044] Furthermore, the hydrogen generator 10 of Example 1 performs the processes of steps S6 to S14 (i.e., the purging operation of cartridge C2 and the pressure-raising operation) while maintaining the valve VH1 open, and closes valve VH1 after the pressure-raising operation. As a result, hydrogen gas is supplied from cartridge C1 to the buffer tank 20 while the purging operation of cartridge C2 and the pressure-raising operation are being performed, and a pressure drop in the buffer tank 20 can be suppressed. Therefore, hydrogen gas can be stably supplied to the external device 99 during the cartridge switching process.

[0045] Furthermore, in the hydrogen generator 10 of Example 1, in steps S2 and S4, prior to the execution of steps S6 to S14 (i.e., the purging operation and pressure increase operation of cartridge C2), the amount of water supplied to cartridge C1 is increased to raise the pressure inside cartridge C1. This allows for more effective suppression of the pressure drop in the buffer tank 20 during the purging operation and pressure increase operation of cartridge C2. As a result, hydrogen gas can be supplied to the external device 99 more stably during the cartridge switching process.

[0046] Furthermore, the hydrogen generator 10 of Example 1 performs a purging operation on the cartridge C2 before the pressure increase operation. This prevents the inert gas present in the cartridge C2 before use from flowing into the buffer tank 20.

[0047] In Example 1, hydrogen gas was supplied from cartridge C1 to buffer tank 20 during the purging operation and pressure increase operation. However, if the pressure drop in buffer tank 20 is small, it is not necessary to supply hydrogen gas from cartridge C1 to buffer tank 20 during the purging operation and pressure increase operation.

[0048] In Example 1, steps S16 and S18 are executed almost simultaneously, but step S16 may be executed before step S18, or step S18 may be executed before step S16. [Examples]

[0049] The hydrogen generator 100 of Embodiment 2 shown in Figure 5 does not have a buffer tank 20. Therefore, the downstream ends of the first hydrogen supply pipe 21 and the second hydrogen supply pipe 22 are directly connected to the upstream end of the main hydrogen supply pipe 26. In addition, in the hydrogen generator 100 of Embodiment 2, the pump 50 is not provided in the common part of the water supply pipe 54, but the pump 51 is provided in the branch pipe 54a and the pump 52 is provided in the branch pipe 54b. The other configurations of the hydrogen generator 100 of Embodiment 2 are the same as those of Embodiment 1.

[0050] Next, the operation of supplying hydrogen gas to the external device 99 will be described. When hydrogen gas is being supplied to the external device 99, the main valve 36 is controlled to be in the open state. In the following description of the operation, it will be assumed that the main valve 36 is open. The hydrogen generator 100 can perform a first operation in which hydrogen gas is generated in cartridge C1 and a second operation in which hydrogen gas is generated in cartridge C2.

[0051] In the first operation, the control device 90 controls the valves VH1, VW1, VO1, VH2, VW2, VO2 and the pumps 51 and 52 as follows. Valve VH1: Open Valve VW1: Open Valve VO1: Closed Valve VH2: Closed Valve VW2: Closed Valve VO2: Closed Pump 51: Operation Pump 52: Stopped

[0052] Figure 6(a) shows the first operation. In the first operation, the water supply to cartridge C2 is stopped by valve VW2 and pump 52. On the other hand, since valve VW1 is open and pump 51 is operating, water is supplied to cartridge C1. As a result, hydrogen gas is generated in cartridge C1. Since valve VH1 is open, the hydrogen gas in cartridge C1 flows to the main hydrogen supply pipe 26 and is supplied to the external device 99. Also in the first operation, the control device 90 provides feedback control to pump 51 based on the pressure P1 in cartridge C1 (i.e., the value detected by pressure sensor PS1). The control device 90 adjusts the amount of water supplied to cartridge C1 by operating pump 51 intermittently, and controls the pressure P1 in cartridge C1 to approximately 190 kPa.

[0053] Next, we will explain the switching process that transitions from the first operation, in which hydrogen gas is generated in cartridge C1, to the second operation, in which hydrogen gas is generated in cartridge C2. The flowchart in Figure 7 shows the switching process. The control device 90 executes the process in Figure 7 when it becomes necessary to switch cartridges, such as when the usage time of cartridge C1 exceeds a reference value. At the timing of the start of the switching in Figure 7, the control device 90 is executing the first operation (i.e., Figure 6(a)).

[0054] In step S20, the control device 90 controls the valve and pump as follows: Valve VW2: Open Valve VO2: Open Pump 52: Operation The status of the other valves and pumps will not be changed.

[0055] Figure 6(b) shows the state of each part in step S20. Since the pump 52 is operating and valve VW2 is open, water is injected into cartridge C2. As a result, hydrogen gas is generated in cartridge C2. Since valve VH2 is closed and purge valve VO2 is open, the gas in cartridge C2 is released to the outside of the hydrogen generator 100 via purge valve VO2. Before use, cartridge C2 is sealed with an inert gas (for example, nitrogen gas). As shown in Figure 6(b), when cartridge C2 is purged, the inert gas inside cartridge C2 is released to the outside. This prevents the inert gas from flowing to the main hydrogen supply pipe 26 in a later step. Also, as shown in Figure 6(b), the state of cartridge C1 is not changed in step S20, so the supply of hydrogen gas from cartridge C1 to the main hydrogen supply pipe 26 continues.

[0056] In step S20, the control device 90 performs a purging operation of cartridge C2 for a certain period of time, and then performs the pressure increase operation in step S22. In step S22, the control device 90 closes the purge valve VO2. The state of the other valves and pumps remains unchanged. Figure 6(c) shows the state of each part in step S22. When the purge valve VO2 is closed, the release of gas from cartridge C2 to the outside stops. As a result, the pressure P2 inside cartridge C2 rises as hydrogen gas is generated inside cartridge C2. In step S24, the control device 90 determines whether the pressure P2 inside cartridge C2 exceeds 190 kPa. The control device 90 repeats steps S22 and S24 until the pressure P2 exceeds 190 kPa.

[0057] As shown in Figure 6(c), the state of cartridge C1 does not change even during the execution of steps S22 and S24, so the supply of hydrogen gas from cartridge C1 to the main hydrogen supply pipe 26 continues.

[0058] When the pressure P2 exceeds 190 kPa, the control device 90 controls the valve and pump in step S26 as follows: Valve VH1: Closed Valve VW1: Closed Pump 51: Stopped Furthermore, in step S28, the control device 90 opens valve VH2. The status of the other valves and pumps will not be changed.

[0059] As shown in Figure 6(d), when valve VW1 closes and pump 51 stops, the water supply to cartridge C1 stops. Also, when valve VH1 closes, the supply of hydrogen gas from cartridge C1 to the main hydrogen supply pipe 26 stops. When valve VH2 opens, the supply of hydrogen gas from cartridge C2 to the main hydrogen supply pipe 26 starts. In this way, by executing steps S26 and S28, the supply of hydrogen gas from cartridge C1 stops and the supply of hydrogen gas from cartridge C2 starts instead. This completes the switchover from the first operation in which hydrogen gas is generated in cartridge C1 to the second operation in which hydrogen gas is generated in cartridge C2. In the second operation after the switchover is complete, the control device 90 intermittently operates pump 50 so that the pressure P2 in cartridge C2 reaches an appropriate value.

[0060] As described above, in the hydrogen generator 100 of Example 2, hydrogen gas is supplied from cartridge C1 to the main hydrogen supply pipe 26 during the purging and pressure-boosting operations of cartridge C2. When cartridge C2 is ready, the supply of hydrogen gas from cartridge C1 is stopped and the supply of hydrogen gas from cartridge C2 is started. Therefore, the supply of hydrogen gas to the main hydrogen supply pipe 26 is maintained during the cartridge switching process. As a result, the switching process can be performed without interrupting the supply of hydrogen gas to the external device 99.

[0061] Furthermore, the hydrogen generator 100 of Example 2 performs a purge operation before the pressure increase operation. This prevents the inert gas present in the cartridge C2 before use from flowing into the main hydrogen supply pipe 26.

[0062] In Example 2, steps S26 and S28 are executed almost simultaneously, but step S26 may be executed slightly before step S28, or step S28 may be executed slightly before step S26.

[0063] In Examples 1 and 2, the switching process from cartridge C1 to cartridge C2 was described, but the switching process from cartridge C2 to cartridge C1 can be performed in the same manner as in Examples 1 and 2.

[0064] The first slot hole 11 is an example of a first mounting part. The second slot hole 12 is an example of a second mounting part. Valve VH1 is an example of a first hydrogen supply valve. Valve VH2 is an example of a second hydrogen supply valve. The water supply pipe 54, pump 50 and valves VW1 and VW2 of Example 1 are an example of a water supply system. The branch pipe 54a, pump 51 and valve VW1 of Example 2 are an example of a first water supply system. The branch pipe 54b, pump 52 and valve VW2 of Example 2 are an example of a second water supply system.

[0065] Although embodiments have been described in detail above, these are merely illustrative and do not limit the scope of the claims. The technologies described in the claims include various modifications and changes to the specific examples illustrated above. The technical elements described in this specification or drawings exhibit technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technologies illustrated in this specification or drawings achieve multiple objectives simultaneously, and achieving even one of these objectives constitutes technical usefulness. [Explanation of Symbols]

[0066] 10: Hydrogen generator, 20: Buffer tank, 21: First hydrogen supply pipe, 22: Second hydrogen supply pipe, 26: Main hydrogen supply pipe, 50-52: Pump, 54: Water supply pipe, 56: Water tank

Claims

1. A hydrogen generator, A first mounting section and a second mounting section to which a cartridge containing a substance that reacts with water to generate hydrogen gas is attached, A water supply device that supplies water to a first cartridge attached to the first mounting part and a second cartridge attached to the second mounting part, Buffer tank and A first hydrogen supply path that supplies hydrogen gas from the first cartridge to the buffer tank, A second hydrogen supply path that supplies hydrogen gas from the second cartridge to the buffer tank, A first hydrogen supply valve that opens and closes the first hydrogen supply path, A second hydrogen supply valve that opens and closes the second hydrogen supply passage, The main hydrogen supply channel supplies hydrogen gas from the buffer tank to the outside, The water supply device, the first hydrogen supply valve, and the control device for controlling the second hydrogen supply valve, It has, When water is being supplied to the first cartridge and hydrogen gas is being supplied from the first cartridge to the buffer tank by opening the first hydrogen supply valve, the control device switches the hydrogen supply source from the first cartridge to the second cartridge, A first process involves stopping the water supply to the first cartridge and supplying water to the second cartridge while closing the second hydrogen supply valve, After the first process, a second process is performed in which the second hydrogen supply valve is opened and hydrogen gas is supplied from the second cartridge to the buffer tank. A hydrogen generator that performs the following action.

2. The hydrogen generator according to claim 1, wherein the control device performs the first process while maintaining the first hydrogen supply valve in an open state, and closes the first hydrogen supply valve after the first process.

3. The hydrogen generator according to claim 2, wherein the control device performs a process of increasing the amount of water supplied to the first cartridge and raising the pressure inside the first cartridge before the first process.

4. The second cartridge further has a purge valve that opens and closes a passage that opens to the outside air, In the first process, the control device opens the purge valve to purge the second cartridge, and after the purging closes the purge valve to increase the pressure inside the second cartridge. A hydrogen generator according to claim 1 or 2.

5. A hydrogen generator, A first mounting section and a second mounting section to which a cartridge containing a substance that reacts with water to generate hydrogen gas is attached, A first water supply device that supplies water to the first cartridge attached to the first mounting portion, A second water supply device that supplies water to the second cartridge attached to the second mounting portion, The main hydrogen supply line that supplies hydrogen gas to the outside, A first hydrogen supply channel that supplies hydrogen gas from the first cartridge to the main hydrogen supply channel, A second hydrogen supply channel that supplies hydrogen gas from the second cartridge to the main hydrogen supply channel, A first hydrogen supply valve that opens and closes the first hydrogen supply path, A second hydrogen supply valve that opens and closes the second hydrogen supply passage, The first water supply device, the second water supply device, the first hydrogen supply valve, and the control device for controlling the second hydrogen supply valve, It has, When water is being supplied to the first cartridge and the first hydrogen supply valve is open, thereby supplying hydrogen gas from the first cartridge to the main hydrogen supply path, and the hydrogen supply source is switched from the first cartridge to the second cartridge, the control device, A first process involves supplying water to the second cartridge while keeping the first hydrogen supply valve open and the second hydrogen supply valve closed, and maintaining that state while supplying water to the first cartridge and the first hydrogen supply valve is open. After the first process, the second process involves opening the second hydrogen supply valve to supply hydrogen gas from the second cartridge to the main hydrogen supply path and closing the first hydrogen supply valve. A hydrogen generator that performs the following action.

6. The second cartridge further has a purge valve that opens and closes a passage that opens to the outside air, In the first process, the control device opens the purge valve to purge the second cartridge, and after the purging closes the purge valve to increase the pressure inside the second cartridge. The hydrogen generator according to claim 5.

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