Hydrogen system

Abstract

To provide a hydrogen system in which heat is effectively utilized.SOLUTION: A hydrogen system comprises: a water electrolysis apparatus 14 in which hydrogen can be generated by water electrolysis; a dehumidifier 15 for removing moisture included in the hydrogen generated in the water electrolysis apparatus 14; and a storage alloy tank 16 for storing the hydrogen from which the moisture is removed by the dehumidifier 15. The hydrogen system is configured so that supply processing is performed, in which heat generated in one of the water electrolysis apparatus 14, the dehumidifier 15, and the storage alloy tank 16 is supplied to another of the water electrolysis apparatus 14, the dehumidifier 15, and the storage alloy tank 16.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to hydrogen system technology. [Background technology]

[0002] Conventionally, techniques for producing hydrogen have been publicly known, for example as described in Patent Document 1.

[0003] The hydrogen production and storage system described in Patent Document 1 includes a hydrogen production device such as a water electrolysis device, and a hydrogen storage device such as a hydrogen absorbing alloy tank. The hydrogen storage device is configured to be able to store hydrogen produced by the hydrogen production device and to be able to release the hydrogen. The hydrogen production and storage system adjusts the amount of hydrogen produced and released based on the predicted and actual values ​​of surplus power.

[0004] Here, the water electrolysis device and hydrogen storage alloy tank described in Patent Document 1 generate heat during operation. For example, when water is electrolyzed with a water electrolysis device, exhaust heat is generated. Since effective use of this heat can lead to energy savings, there is a demand for technology that can effectively utilize the heat generated during hydrogen production and storage. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2020-54085 A Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and the problem to be solved by the present invention is to provide a hydrogen system capable of effectively utilizing heat. [Means for solving the problem]

[0007] The problem to be solved by the present invention has been described above, and the means for solving this problem will now be described.

[0008] That is, in claim 1, the device comprises a water electrolysis unit capable of producing hydrogen by electrolyzing water, a dehumidification unit that removes moisture contained in hydrogen produced in the water electrolysis unit, and a storage unit that stores hydrogen from which moisture has been removed in the dehumidification unit, and is configured to perform a supply process for supplying heat generated in one device among the water electrolysis unit, the dehumidification unit, and the storage unit to another device among the water electrolysis unit, the dehumidification unit, and the storage unit.

[0009] In claim 2, the storage unit is cooled when storing hydrogen and is heated when releasing the stored hydrogen, and the supply process includes a first process that is performed when hydrogen produced by the operations of the water electrolysis unit and the dehumidification unit is stored in the storage unit, and a second process that is performed when hydrogen stored in the storage unit is released.

[0010] In claim 3, the first process includes a first water utilization process in which heat generated in the one device is supplied to the other device using water as a heat medium.

[0011] In claim 4, the first water utilization process includes a process of supplying heat generated in at least one of the water electrolysis section and the storage section to the dehumidification section.

[0012] In claim 5, in the first water utilization process, when the temperature of the water is lower than a first threshold value based on the temperature at which hydrogen can be stored in the storage section, heat generated in the storage section is supplied to the dehumidification section.

[0013] In claim 6, in the first water utilization process, hydrogen is produced in the water electrolysis section by utilizing the water used as a heat medium.

[0014] In claim 7, the first process includes a first air utilization process in which heat generated in at least one of the water electrolysis unit and the storage unit is supplied to the dehumidification unit using air as a heat medium.

[0015] In claim 8, the second process includes a second air utilization process in which heat generated in at least one of the water electrolysis section and the dehumidification section is supplied to the storage section using air as a heat medium.

[0016] In claim 9, the second process includes a second water utilization process in which the water is used as a heat medium to heat the storage unit when the temperature of the water is higher than a second threshold value based on the temperature at which hydrogen can be released from the storage unit.

[0017] In claim 10, the second process includes a second water utilization process in which the storage unit is heated using the water as a heat medium when the temperature of the water is higher than a second threshold value based on the temperature at which hydrogen can be released from the storage unit, and a waste heat utilization process in which the storage unit is heated using waste heat generated by a fuel cell using hydrogen in the storage unit when the storage unit is further heated after performing the second air utilization process and the second water utilization process. Effect of the Invention

[0018] The present invention has the following advantages.

[0019] According to claim 1, heat can be effectively utilized.

[0020] In claim 2, different processes can be carried out depending on when hydrogen is stored and when it is released.

[0021] In claim 3, water can be used to efficiently transfer heat from one device to another.

[0022] According to claim 4, heat can be efficiently transferred from at least one of the water electrolysis section and the storage section to the dehumidification section.

[0023] In claim 5, low-temperature water can be used to efficiently transfer heat from the storage section to the dehumidifying section.

[0024] According to claim 6, water can be effectively utilized in the first water treatment.

[0025] In claim 7, air can be used to effectively utilize heat generated in at least one of the water electrolysis unit and the storage unit.

[0026] In claim 8, air is used, and heat generated in at least one of the water electrolysis section and the dehumidification section can be effectively utilized.

[0027] In claim 9, the storage section can be heated more efficiently by using high-temperature water.

[0028] According to claim 10, the exhaust heat of the fuel cell can be effectively utilized. [Brief description of the drawings]

[0029] [Figure 1] FIG. 1 is a block diagram showing a hydrogen system according to an embodiment of the present invention. [Diagram 2] 1A is a block diagram showing an example of a path through which air flows, and FIG. 1B is a block diagram showing an example of a path through which water flows. [Diagram 3] 13 is a flowchart showing a distribution control process. [Figure 4] 4 is a block diagram showing the flow directions of air and water when hydrogen is stored in the storage alloy tank; FIG. [Diagram 5] FIG. 4 is a block diagram showing the flow directions of air and water when hydrogen is released from the storage alloy tank. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] The following describes a hydrogen system 10 according to one embodiment of the present invention.

[0031] The hydrogen system 10 shown in FIG. 1 is for using hydrogen as an energy source. More specifically, the hydrogen system 10 produces and stores hydrogen, and uses the hydrogen to generate power. The hydrogen system 10 is primarily used in factories, residential areas, and the like. The hydrogen system 10 supplies power generated using hydrogen to power loads in the factories, residential areas, and the like. The hydrogen system 10 primarily comprises a solar power generation device 11, a storage battery 12, a pure water production device 13, a water electrolysis device 14, a dehumidifier 15, a storage alloy tank 16, and a fuel cell 17.

[0032] The solar power generation device 11 is a device that generates power by utilizing sunlight. The solar power generation device 11 is composed of a solar cell panel and the like. The solar power generation device 11 is installed in a sunny location, for example, on the roof of a house. The solar power generation device 11 is connected to the storage battery 12 and the like so that the generated power can be output to the storage battery 12, the pure water production device 13, and the water electrolysis device 14.

[0033] The storage battery 12 is configured to be able to charge and discharge electric power. The storage battery 12 is, for example, a lithium ion battery. The storage battery 12 is configured to be able to charge electric power from the solar power generation device 11. The storage battery 12 is also connected to the pure water production device 13 and the water electrolysis device 14 so that the electric power charged in the pure water production device 13 and the water electrolysis device 14 can be discharged. The storage battery 12 can also be charged with electric power other than that of the solar power generation device 11 (for example, electric power from a system power source).

[0034] The pure water production apparatus 13 purifies water to produce pure water. The pure water production apparatus 13 can use the power generated by the solar power generation apparatus 11, the discharged power from the storage battery 12, and the power from the fuel cell 17 as power for operation. The pure water production apparatus 13 can also be operated using power different from that in this embodiment (for example, power from a power grid). The pure water production apparatus 13 supplies the produced pure water to a pure water tank (not shown). The pure water supplied to the pure water tank is introduced into the water electrolysis apparatus 14 when the water electrolysis apparatus 14 is in operation.

[0035] The water electrolysis device 14 produces hydrogen using electric power. The water electrolysis device 14 produces hydrogen by electrolyzing the pure water produced by the pure water production device 13. The water electrolysis device 14 mainly uses the electric power generated by the solar power generation device 11 as the electric power used for producing hydrogen. The water electrolysis device 14 can also use the discharged electric power from the storage battery 12, the electric power from the fuel cell 17, and the electric power from the system power supply as the electric power used for producing hydrogen.

[0036] The dehumidifier 15 removes moisture contained in gas introduced from the outside. The dehumidifier 15 is, for example, a heater-type dehumidifier, a desiccant-type dehumidifier, or the like. In the above-mentioned water electrolysis device 14, hydrogen is produced by electrolysis of water, and therefore the hydrogen contains a large amount of moisture. For this reason, in this embodiment, the hydrogen produced by the water electrolysis device 14 is introduced into the dehumidifier 15, and the moisture contained in the hydrogen is removed. This makes it possible to increase the purity of the hydrogen.

[0037] The storage alloy tank 16 is a container for storing hydrogen from which moisture has been removed by the dehumidifier 15. The storage alloy tank 16 has a case filled with a storage alloy, and a sensor (not shown) capable of measuring the temperature of the storage alloy (storage alloy temperature). The storage alloy is an alloy that can take in (absorb) hydrogen and also release the absorbed hydrogen. Depending on the temperature, the storage alloy changes between a state in which it easily absorbs hydrogen and a state in which it easily releases the absorbed hydrogen.

[0038] More specifically, when the temperature of the storage alloy is within a predetermined temperature range, the storage alloy is in a state in which it is easy to store hydrogen. Therefore, the temperature of the storage alloy tank 16 is adjusted so that the temperature of the storage alloy is within that temperature range when storing (absorbing) hydrogen. On the other hand, when the temperature of the storage alloy is within a temperature range lower than the lower limit of the temperature range, the storage alloy is in a state in which it is easy to release hydrogen. Therefore, the temperature of the storage alloy tank 16 is adjusted so that the temperature of the storage alloy is within that temperature range when releasing hydrogen.

[0039] The fuel cell 17 is a device that generates power using gas fuel such as hydrogen. The fuel cell 17 is configured by a polymer electrolyte fuel cell (PEFC: Polymer Electrolyte Fuel Cell) or a solid oxide fuel cell (SOFC: Solid Oxide Fuel Cell), etc. The fuel cell 17 can generate power using hydrogen released from the storage alloy tank 16. The fuel cell 17 is also connected to an electric power load, etc., so that the generated power can be output to the electric power loads of the above-mentioned factories, residential areas, etc., and the pure water production system 13.

[0040] The hydrogen system 10 can operate in a storage state and a release state. The storage state is a state in which hydrogen is stored in the storage alloy tank 16 (storage alloy). Specifically, the storage state is a state in which the pure water production system 13, the water electrolysis system 14, and the dehumidifier 15 are operating, and the fuel cell 17 is stopped. In the storage state, pure water produced in the pure water production system 13 is electrolyzed in the water electrolysis system 14 to produce hydrogen, and moisture contained in the hydrogen is removed by the dehumidifier 15. The storage alloy tank 16 also stores the hydrogen from which moisture has been removed.

[0041] The release state is a state in which hydrogen is released from the storage alloy tank 16. More specifically, the release state is a state in which the fuel cell 17 generates (operates) electricity using the hydrogen released from the storage alloy tank 16. In the release state, the pure water production system 13, the water electrolysis system 14, and the dehumidifier 15 may or may not be operating. For example, when it is necessary to produce hydrogen, the pure water production system 13 and the like are operated, and hydrogen production, hydrogen dehumidification, and electricity generation by the fuel cell 17 are performed simultaneously. In addition, when it is not necessary to produce hydrogen, the pure water production system 13 and the like are stopped, and only electricity generation by the fuel cell 17 is performed.

[0042] Here, in the hydrogen system 10, heat is generated by the operation of each of the above-mentioned devices. Specifically, in the water electrolysis device 14, exhaust heat is generated when water is electrolyzed. In addition, the dehumidifier 15 and the fuel cell 17 generate exhaust heat as they operate. The exhaust heat from the fuel cell 17 is stored as hot water in a hot water storage tank (not shown).

[0043] Furthermore, the storage alloy tank 16 (storage alloy) generates heat as it absorbs hydrogen, and may rise to a temperature at which it becomes difficult to absorb hydrogen. For this reason, when storing hydrogen, the storage alloy tank 16 must be cooled. On the other hand, the storage alloy tank 16 absorbs heat as it releases hydrogen, and may fall to a temperature at which it becomes difficult to release hydrogen. For this reason, when releasing hydrogen, the storage alloy tank 16 must be heated.

[0044] The hydrogen system 10 of this embodiment is capable of transferring heat between each of the devices. More specifically, heat can be transferred between the water electrolysis device 14, the dehumidifier 15, and the storage alloy tank 16. In this embodiment, heat can also be transferred from the fuel cell 17 to the storage alloy tank 16. Air and water are used as heat media for transferring heat.

[0045] An example of a heat medium flow path will be described below. First, an example of an air flow path will be described with reference to Fig. 2(a). Fig. 2(a) shows a first path K10 and a second path K20 through which air can flow.

[0046] The first path K10 is a path for introducing heat generated in the water electrolysis device 14 to the dehumidifier 15. One end of the first path K10 is open to the outside. The other end of the first path K10 is connected to the dehumidifier 15. The first path K10 is configured to have a heat exchanger provided in the middle of the first path K10, for example, and to exchange heat between the water electrolysis device 14 and the air. A first fan K11 is provided in the middle of the first path K10. The first fan K11 can generate an air flow from one end to the other end (the dehumidifier 15) by rotating its blades.

[0047] The second path K20 is a path for transferring heat between the dehumidifier 15 and the storage alloy tank 16. One end of the second path K20 is open to the outside. The other end of the second path K20 is connected to the dehumidifier 15. The second path K20 is configured to have a heat exchanger provided in the middle of the second path K20, for example, and to exchange heat between the storage alloy tank 16 and the air. A second fan K21 is provided in the middle of the second path K20.

[0048] The second fan K21 can generate an air flow from one end to the other end (dehumidifier 15) by rotating the blades in a first direction. Also, the second fan K21 can generate an air flow from the other end to the one end by rotating the blades in a second direction opposite to the first direction.

[0049] Next, an example of a water flow path will be described with reference to Fig. 2(b). Fig. 2(b) shows a third path K30 through which water can flow. The third path K30 includes a first portion K31 to a seventh portion K37.

[0050] The upstream end of the first part K31 is configured to be connected to a water faucet or the like so that tap water (clean water) flows in. The tap water that flows into the first part K31 is heat exchanged between the tap water and the storage alloy tank 16 by a heat exchanger provided at the downstream end of the first part K31.

[0051] An upstream end of the second portion K32 is connected to a downstream end of the first portion K31. The tap water flowing from the first portion K31 into the second portion K32 is heat exchanged between the tap water and the water electrolysis device 14 by a heat exchanger provided at the downstream end of the second portion K32.

[0052] An upstream end of the third portion K33 is configured to allow tap water to flow in. The tap water that has flowed into the third portion K33 undergoes heat exchange with the water electrolysis device 14 by a heat exchanger provided at a downstream end of the third portion K33.

[0053] An upstream end of the fourth portion K34 is connected to downstream ends of the second portion K32 and the third portion K33. The tap water flowing from the second portion K32 and the third portion K33 into the fourth portion K34 is heat exchanged between the tap water and the dehumidifier 15 by a heat exchanger provided at the downstream end of the fourth portion K34.

[0054] The fifth section K35 is configured to connect the downstream end of the fourth section K34 and the pure water producing apparatus 13.

[0055] An upstream end of the sixth portion K36 is connected to the hot water tank of the fuel cell 17, and is configured so that hot water from the hot water tank flows in. The hot water that flows into the sixth portion K36 is heat exchanged with the storage alloy tank 16, similar to the tap water that flows into the first portion K31.

[0056] The seventh portion K37 is configured to connect the downstream ends of the first portion K31 and the sixth portion K36 to the pure water producing apparatus 13.

[0057] In the third path K30, the flow of water (tap water and hot water) is controlled, for example, by opening and closing valves provided in each of the portions K31 to K37. For example, tap water can be circulated through the first portion K31, the second portion K32, the fourth portion K34, and the fifth portion K35, and heat can be exchanged between the tap water and the storage alloy tank 16, the water electrolysis device 14, and the dehumidifier 15. In addition, for example, tap water and hot water can be circulated through the first portion K31, the sixth portion K36, and the seventh portion K37, and heat can be exchanged between the tap water and the hot water and the storage alloy tank 16.

[0058] The flow control process for controlling the flow of the heat medium (air and water) described above will be described below with reference to Fig. 2 to Fig. 5. The flow control process shown in Fig. 3 is executed by a device (control unit 18) capable of controlling the flow of the heat medium.

[0059] 2(a) is configured to control the flow of air by controlling the first fan K11 and the second fan K21. The control unit 18 is also configured to control the flow of water in the third path K30 by controlling a valve provided in the third path K30, for example.

[0060] The control unit 18 can also acquire the measurement results of the outside air temperature and the tap water temperature by communicating with an outside air temperature sensor that measures the outside air temperature (outside air temperature) and a water temperature sensor that measures the tap water temperature. The control unit 18 can also acquire the measurement results of the storage alloy temperature by communicating with a sensor provided in the storage alloy tank 16.

[0061] The control unit 18 repeatedly executes the flow control process shown in Fig. 3 at predetermined time intervals, for example. By executing the flow control process, the control unit 18 controls the flow of the heat medium (air, etc.) so that heat generated in one device in the hydrogen system 10 is supplied to another device in the hydrogen system 10 that requires heat. This allows for effective use of heat. The contents of the flow control process will be described in detail below. When the flow control process is started, the control unit 18 proceeds to step S10.

[0062] In step S10, if the state of the hydrogen system 10 is the storage state, the control unit 18 proceeds to step S20. Note that the storage state is a state in which hydrogen produced by the operation of the water purifier 13 and the like is stored in the storage alloy tank 16, as described above.

[0063] If the hydrogen system 10 is in the discharging state in step S10, the control unit 18 proceeds to step S90. The discharging state is a state in which the fuel cell 17 generates power using hydrogen discharged from the storage alloy tank 16, as described above.

[0064] In step S10, there is no particular limitation on the method for detecting the state of the hydrogen system 10. For example, the control unit 18 can detect the occlusion state when the power generated by the fuel cell 17 is less than a predetermined threshold, and detect the release state when the power generated is equal to or greater than the threshold.

[0065] 3 and 4, in step S20, the control unit 18 introduces outside air from the water electrolysis device 14 to the dehumidifier 15. More specifically, the control unit 18 controls the first fan K11 (see FIG. 2(a)) to cause the outside air introduced into the first path K10 to flow from the water electrolysis device 14 to the dehumidifier 15.

[0066] Here, the water electrolysis device 14 is operating in an occlusion state (step S20) and has a higher temperature than the outside air. Therefore, the air (outside air) flowing through the first path K10 removes heat from the water electrolysis device 14 and is introduced into the dehumidifier 15. The dehumidifier 15 uses the heat of the air (heat generated in the water electrolysis device 14) to remove the moisture contained in the hydrogen. In this way, the heat generated in the water electrolysis device 14 can be utilized to achieve energy conservation. When the process of step S20 is completed, the control unit 18 proceeds to step S30.

[0067] In step S30, the control unit 18 acquires the measurement result of the outside air temperature from the outside air temperature sensor, and if the measurement result is less than the absorption temperature (step S30: YES), the control unit 18 proceeds to step S40. On the other hand, if the measurement result of the outside air temperature is equal to or higher than the absorption temperature (step S30: NO), the control unit 18 proceeds to step S50. The absorption temperature is a target value of the temperature of the absorption alloy in the absorption state. The absorption temperature is, for example, a temperature within a temperature range in which the absorption alloy is in a state in which it is easy to absorb hydrogen.

[0068] In step S40, the control unit 18 introduces outside air (air) into the storage alloy tank 16. More specifically, the control unit 18 controls the second fan K21 (see FIG. 2(a)) to cause the outside air introduced into the second path K20 to flow from the storage alloy tank 16 to the dehumidifier 15.

[0069] At this time, the low-temperature air (outside air that is lower than the storage temperature) flowing through the second path K20 absorbs heat from the storage alloy tank 16 and is introduced into the dehumidifier 15. This makes it possible to cool the storage alloy tank 16 using the air. Also, the heat of the storage alloy tank 16 can be used to dehumidify the hydrogen in the dehumidifier 15. When the processing of step S40 is completed, the control unit 18 proceeds to step S50.

[0070] In step S50, the control unit 18 acquires the measurement result of the storage alloy temperature from the sensor provided in the storage alloy tank 16, and if the measurement result is higher than the storage temperature (step S50: YES), the control unit 18 proceeds to step S60. On the other hand, if the measurement result of the storage alloy temperature is equal to or lower than the storage temperature (step S50: NO), the control unit 18 proceeds to step S80.

[0071] In step S60, the control unit 18 acquires the measurement result of the tap water temperature from the water temperature sensor, and if the measurement result is less than the occlusion temperature (step S60: YES), the control unit 18 proceeds to step S70. On the other hand, if the measurement result of the tap water temperature is equal to or higher than the occlusion temperature (step S60: NO), the control unit 18 proceeds to step S80.

[0072] In step S70, the control unit 18 uses tap water to cool the storage alloy tank 16 (storage alloy). More specifically, the control unit 18 controls a valve or the like to cause tap water to flow into the first portion K31 of the third path K30. The tap water, which is lower in temperature than the storage temperature and circulates through the first portion K31, removes heat from the storage alloy tank 16. In this way, when air alone is insufficient to cool the storage alloy tank 16 (step S50: YES), the control unit 18 uses tap water to further cool the storage alloy tank 16. When the processing of step S70 is completed, the control unit 18 proceeds to step S80.

[0073] In step S80, the control unit 18 uses tap water in the water electrolysis device 14, the dehumidifier 15, and the pure water production device 13. At this time, the control unit 18 causes the tap water to flow through the fourth portion K34 and the fifth portion K35. Note that different tap water flows into the fourth portion K34 depending on the step immediately before step S80.

[0074] For example, when the control unit 18 transitions from step S70 to step S80, the tap water that has flowed through the second portion K32 flows into the fourth portion K34. The tap water absorbs heat from the water electrolysis device 14 and transfers it to the dehumidifier 15. This allows the dehumidifier 15 to dehumidify hydrogen by utilizing the heat from the storage alloy tank 16 and the water electrolysis device 14.

[0075] Furthermore, for example, when moving from step S50 or step S60 to step S80, the control unit 18 causes tap water from the third portion K33 (see FIG. 2(b)) to flow into the fourth portion K34. The tap water absorbs heat from the water electrolysis device 14 and moves it to the dehumidifier 15. As a result, even if the storage alloy tank 16 is not cooled with tap water, the heat of the water electrolysis device 14 can be used to dehumidify hydrogen in the dehumidifier 15.

[0076] In step S80, the tap water that has flowed through the fourth portion K34 is introduced into the pure water production system 13 via the fifth portion K35. The pure water production system 13 produces pure water using the tap water and supplies it to the water electrolysis system 14. This allows the tap water used for heat exchange to be effectively utilized without being discarded. When the process of step S80 ends, the control unit 18 ends the flow control process.

[0077] In step S90, which is performed if the state of the hydrogen system 10 is the discharge state (the fuel cell 17 is generating electricity) in step S10, the control unit 18 proceeds to step S100 if the water electrolysis device 14 is operating (step S90: YES). On the other hand, if the water electrolysis device 14 is stopped (step S90: NO), the control unit 18 proceeds to step S110.

[0078] The method for detecting the state (operation or non-operation) of the water electrolysis device 14 in step S90 is not particularly limited. For example, the control unit 18 can detect that the water electrolysis device 14 is operating when the power consumption of the water electrolysis device 14 is equal to or greater than a predetermined threshold, and can detect that the water electrolysis device 14 is stopped when the power consumption is less than the threshold.

[0079] In step S90, it is sufficient to be able to determine whether hydrogen is being produced, and the method is not limited to this embodiment (whether the water electrolysis device 14 is operating or not). For example, the control unit 18 may proceed to step S100 or step S110 depending on whether the dehumidifier 15 is operating or not.

[0080] 3 and 5, in step S100, the control unit 18 introduces outside air into the water electrolysis device 14, the dehumidifier 15, and the storage alloy tank 16 in that order. At this time, the control unit 18 introduces outside air from the water electrolysis device 14 to the dehumidifier 15 via the first path K10 by processing similar to that of step S20 described above. The control unit 18 also controls the second fan K21 (see FIG. 2(a)) to cause the outside air to flow from the dehumidifier 15 to the storage alloy tank 16 via the second path K20.

[0081] Here, in step S100, the temperature of the storage alloy tank 16 (storage alloy) drops due to an endothermic reaction accompanying the release of hydrogen, and so it becomes necessary to heat it. In step S100, by circulating outside air from the dehumidifier 15 to the storage alloy tank 16, the heat of the water electrolysis device 14 and the dehumidifier 15 can be supplied to the storage alloy tank 16 via the air (heating the storage alloy tank 16). This allows the heat of the water electrolysis device 14 and the dehumidifier 15 to be effectively utilized. When the processing of step S100 is completed, the control unit 18 proceeds to step S130.

[0082] In step S110, the control unit 18 acquires the measurement result of the outside air temperature from the outside air temperature sensor, and if the measurement result is higher than the release temperature (step S110: YES), the control unit 18 proceeds to step S120. On the other hand, if the measurement result of the outside air temperature is equal to or lower than the release temperature (step S110: NO), the control unit 18 proceeds to step S130. The release temperature is a target value for the storage alloy temperature in the release state. The release temperature is, for example, a temperature within a temperature range in which the storage alloy is in a state in which it is easy to release hydrogen.

[0083] In step S120, the control unit 18 introduces outside air into the storage alloy tank 16 by the same process as in step S40 (see FIG. 4). This makes it possible to heat the storage alloy tank 16 (storage alloy) by using air at a higher temperature than the release temperature. When the process of step S120 is completed, the control unit 18 proceeds to step S130.

[0084] In step S130, the control unit 18 acquires the measurement result of the storage alloy temperature from the sensor provided in the storage alloy tank 16, and if the measurement result is below the release temperature (step S130: YES), the control unit 18 proceeds to step S140. On the other hand, if the measurement result of the storage alloy temperature is equal to or higher than the release temperature (step S130: NO), the control unit 18 ends the flow control process.

[0085] In step S140, the control unit 18 acquires the measurement result of the tap water temperature from the water temperature sensor, and if the measurement result is higher than the discharge temperature (step S140: YES), the control unit 18 proceeds to step S150. On the other hand, if the measurement result of the tap water temperature is equal to or lower than the discharge temperature (step S140: NO), the control unit 18 proceeds to step S160.

[0086] In step S150, the control unit 18 uses tap water to heat the storage alloy tank 16 (storage alloy). Specifically, the control unit 18 causes tap water to flow into the first portion K31 of the third path K30. This makes it possible to heat the storage alloy tank 16 using tap water that is hotter than the release temperature. The control unit 18 also introduces the tap water into the pure water production system 13 via the seventh portion K37. The pure water production system 13 produces pure water using the tap water. The pure water produced by the pure water production system 13 is appropriately processed depending on whether the water electrolysis system 14 is operating (whether hydrogen is being produced).

[0087] For example, when the water electrolysis device 14 is operating (step S90: YES), the pure water produced by the pure water production device 13 is supplied to the water electrolysis device 14, as in step S80. On the other hand, when the water electrolysis device 14 is stopped (step S90: NO), the pure water is stored in the pure water tank. The pure water stored in the pure water tank is supplied to the water electrolysis device 14 when the water electrolysis device 14 is operating. This allows the heated tap water in the storage alloy tank 16 to be used effectively without being discarded. When the processing of step S150 is completed, the control unit 18 proceeds to step S160.

[0088] In step S160, control unit 18 compares the storage alloy temperature measurement result with the release temperature, similar to step S130. If the storage alloy temperature measurement result is less than the release temperature (step S160: YES), control unit 18 proceeds to step S170. On the other hand, if the storage alloy temperature measurement result is equal to or greater than the release temperature (step S160: NO), control unit 18 ends the flow control process.

[0089] In step S170, the control unit 18 utilizes the exhaust heat of the fuel cell 17 to heat the storage alloy tank 16 (storage alloy). Specifically, the control unit 18 causes the hot water (hot water stored in the hot water tank) generated by the exhaust heat of the fuel cell 17 to flow into the sixth portion K36 of the third path K30. In this way, when the air and tap water alone are not sufficient to heat the storage alloy tank 16 (step S160: YES), the control unit 18 further heats the storage alloy tank 16 using the exhaust heat of the fuel cell 17. The control unit 18 also introduces the hot water used for heating into the pure water manufacturing device 13 via the seventh portion K37. When the process of step S170 ends, the control unit 18 ends the flow control process.

[0090] According to the above-described flow control process, heat can be exchanged in multiple stages between the multiple devices of the hydrogen system 10 and the heat medium (air and water), enabling cascaded utilization of heat. For example, as shown in Fig. 4, air that has been heat exchanged with the water electrolysis device 14 can be further heat exchanged with the dehumidifier 15, so that the heat of the water electrolysis device 14 can be utilized by the dehumidifier 15 (step S20). Also, as shown in Fig. 5, air that has been heat exchanged with the dehumidifier 15 can be further heat exchanged with the storage alloy tank 16, so that the exhaust heat of the dehumidifier 15 can be utilized for heating the storage alloy tank 16 (step S100).

[0091] In this way, heat generated by one device in the hydrogen system 10 can be used by another device that requires heat, making effective use of heat and achieving energy savings throughout the hydrogen system 10.

[0092] Furthermore, the flow control process changes the route through which the heat medium (air and water) flows depending on whether hydrogen is being stored (steps S20 to S80) or released (steps S90 to S170). For example, when hydrogen is being stored in the storage alloy tank 16, the storage alloy tank 16 needs to be cooled. For this reason, as shown in Fig. 4, in the flow control process, the heat medium is circulated from the storage alloy tank 16 to the dehumidifier 15 to cool the storage alloy tank 16 and introduce the heat of the storage alloy tank 16 into the dehumidifier 15 (steps S40, S70, and S80).

[0093] In contrast, when releasing hydrogen from the storage alloy tank 16, it is necessary to heat the storage alloy tank 16. For this reason, as shown in Fig. 5, in the flow control process, a heat medium is caused to flow from the dehumidifier 15 toward the storage alloy tank 16, and the exhaust heat from the dehumidifier 15 is used to heat the storage alloy tank 16 (step S100). In this way, in the flow control process, the flow direction of the heat medium can be appropriately controlled so that the heat medium flows from the heat generating device toward the heat absorbing device.

[0094] As described above, the hydrogen system 10 of this embodiment comprises a water electrolysis device 14 (water electrolysis section) capable of producing hydrogen by electrolyzing water, a dehumidifier 15 (dehumidification section) that removes moisture contained in the hydrogen produced by the water electrolysis device 14, and a storage alloy tank 16 (storage section) that stores the hydrogen from which the moisture has been removed by the dehumidifier 15, and is configured to perform a supply process (steps S10 to S170, flow control process) to supply heat generated in one device among the water electrolysis device 14, the dehumidifier 15, and the storage alloy tank 16 to another device among the water electrolysis device 14, the dehumidifier 15, and the storage alloy tank 16.

[0095] By configuring in this way, heat can be effectively utilized.

[0096] In addition, the storage alloy tank 16 is cooled when hydrogen is stored and heated when the stored hydrogen is released, and the supply process includes a first process (steps S20 to S80) that is performed when hydrogen produced by the operation of the water electrolysis device 14 and the dehumidifier 15 is stored in the storage alloy tank 16, and a second process (steps S90 to S170) that is performed when the hydrogen stored in the storage alloy tank 16 is released.

[0097] With this configuration, different processes can be performed depending on whether hydrogen is stored or released. With this configuration, for example, it is possible to supply heat from the storage alloy tank 16, which needs to be cooled when hydrogen is stored, to other equipment (see FIG. 4), and to supply heat from other equipment to the storage alloy tank 16, which needs to be heated when hydrogen is released (see FIG. 5). This allows for appropriate heat control, making it possible to utilize heat more effectively.

[0098] The first process also includes a first water use process (steps S70 and S80) in which heat generated in the one device is supplied to the other device using water as a heat medium.

[0099] With this configuration, it is possible to efficiently transfer heat from one device to another by utilizing water, which has a relatively high thermal conductivity.

[0100] The first water utilization process includes a process of supplying heat generated in at least one of the water electrolysis device 14 and the storage alloy tank 16 to the dehumidifier 15 (steps S70 and S80).

[0101] With this configuration, heat can be efficiently transferred from at least one of the water electrolysis device 14 and the storage alloy tank 16 to the dehumidifier 15 .

[0102] In addition, in the first water utilization process, when the temperature of the water is lower than a first threshold value (storage temperature) based on the temperature at which hydrogen can be stored in the storage alloy tank 16 (step S60: YES), the heat generated in the storage alloy tank 16 is supplied to the dehumidifier 15.

[0103] With this configuration, it is possible to efficiently transfer heat from storage alloy tank 16 to dehumidifier 15 using low-temperature water.

[0104] In the first water utilization process, hydrogen is produced in the water electrolysis device 14 by utilizing the water used as a heat medium (see FIG. 4).

[0105] With this configuration, the water in the first water treatment can be effectively utilized without being discarded.

[0106] The first process also includes a first air utilization process (steps S20-S40) in which heat generated in at least one of the water electrolysis device 14 or the storage alloy tank 16 is supplied to the dehumidifier 15 using air as a heat medium.

[0107] With this configuration, it is possible to effectively utilize the heat generated in at least one of the water electrolysis device 14 and the storage alloy tank 16 by using air.

[0108] The second process also includes a second air utilization process (steps S100-S120) in which heat generated by at least one of the water electrolysis device 14 and the dehumidifier 15 is supplied to the storage alloy tank 16 using air as a heat medium.

[0109] With this configuration, it is possible to effectively utilize the heat generated by at least one of the water electrolysis device 14 and the dehumidifier 15 by using air.

[0110] In addition, the second water utilization process involves using the water as a heat medium to heat the storage alloy tank 16 when the temperature of the water is higher than a second threshold value (release temperature) based on the temperature at which hydrogen can be released from the storage alloy tank 16 (step S140: YES).

[0111] With this configuration, the storage alloy tank 16 can be heated more efficiently using high-temperature water.

[0112] In addition, the second process includes a second water utilization process (step S150) in which the water is used as a heat medium to heat the storage alloy tank 16 when the temperature of the water is higher than a second threshold value (release temperature) based on the temperature at which hydrogen can be released from the storage alloy tank 16, and a waste heat utilization process (step S170) in which the storage alloy tank 16 is heated using waste heat generated when the fuel cell 17 generates electricity using the hydrogen in the storage alloy tank 16 when the storage alloy tank 16 is further heated after performing the second air utilization process (steps S100-S120) and the second water utilization process (step S160: YES).

[0113] With this configuration, the exhaust heat of the fuel cell 17 can be utilized more effectively. Specifically, the exhaust heat of the fuel cell 17 is generated relatively stably and is therefore more easily utilized by devices external to the hydrogen system 10 than air and water. By prioritizing heating of the storage alloy tank 16 with air and water (steps S100, S120, S150) over heating with the exhaust heat of the fuel cell 17 (step S170), the storage alloy tank 16 can be heated with air and water as much as possible. This makes it easier to supply the exhaust heat of the fuel cell 17 (easily utilized exhaust heat) to external devices, and therefore the exhaust heat of the fuel cell 17 can be utilized more effectively.

[0114] The water electrolysis device 14 according to this embodiment is one embodiment of the water electrolysis section according to the present invention. Moreover, the dehumidifier 15 according to this embodiment is one embodiment of a dehumidifying section according to the present invention. The storage alloy tank 16 according to this embodiment is one embodiment of a storage section according to the present invention. The distribution control process according to this embodiment is an embodiment of a supply process according to the present invention. Moreover, the processing of steps S20 to S80 according to this embodiment is an embodiment of the first processing according to the present invention. Moreover, steps S90 to S170 according to this embodiment are an embodiment of the second process according to the present invention. Moreover, steps S70 and S80 according to this embodiment are one embodiment of a first water-use treatment process according to the present invention. Moreover, steps S20 to S40 according to this embodiment are one embodiment of the first air utilization process according to the present invention. Moreover, steps S100 to S120 according to this embodiment are one embodiment of the second air utilization process according to the present invention. Moreover, step S150 according to this embodiment is one embodiment of the second water-use treatment according to the present invention. Moreover, step S170 according to this embodiment is one embodiment of the exhaust heat utilization process according to the present invention.

[0115] Although the embodiment of the present invention has been described above, the present invention is not limited to the above configuration, and various modifications are possible within the scope of the invention described in the claims.

[0116] For example, while it has been assumed that the pure water production system 13 and the water electrolysis system 14 are supplied with electricity from the solar power generation system 11 or the like, the source of electricity supplied to the pure water production system 13 or the like is not particularly limited. It is preferable that the pure water production system 13 or the like operates using electricity derived from renewable energy (wind power, hydroelectric power, etc.). This can contribute to energy saving.

[0117] In this embodiment, air and water are used as heat transfer media to effectively utilize heat between the devices, but the heat transfer media are not limited to this embodiment and can be changed as desired. For example, it is also possible to effectively utilize heat by using only either air or water. The type of water used as the heat transfer media is not limited to this embodiment (tap water), and well water, etc. can also be used.

[0118] In this embodiment, hydrogen is stored in the storage alloy tank 16, but the configuration of the storage unit that stores hydrogen is not limited to the storage alloy tank 16 and can be changed as desired. For example, hydrogen can be stored in a pressure accumulator tank, an organic hydride, or the like.

[0119] In the flow control process, the heat generated in the water electrolysis device 14 and the storage alloy tank 16 in the storage state is supplied to the dehumidifier 15 (steps S20-S40), but the source of heat supply to the dehumidifier 15 is not limited to this embodiment. For example, it is also possible to supply only the heat generated in either the water electrolysis device 14 or the storage alloy tank 16 to the dehumidifier 15.

[0120] In the flow control process, in step S60, the tap water temperature is compared with the storage temperature, but the comparison target with the tap water temperature is not limited to the storage temperature. In step S60, the tap water temperature can also be compared with other indices that can determine whether or not the temperature is at a temperature at which hydrogen can be stored in the storage alloy tank 16.

[0121] In the flow control process, when the water electrolysis device 14 is operating (step S90: YES), the heat generated in the water electrolysis device 14 and the dehumidifier 15 is supplied to the storage alloy tank 16 (see FIG. 5), but the source of the heat supply to the storage alloy tank 16 is not limited to this embodiment. For example, it is also possible to supply only the heat generated in either the water electrolysis device 14 or the dehumidifier 15 to the storage alloy tank 16.

[0122] In the flow control process, in step S140, the tap water temperature is compared with the release temperature, but the comparison target with the tap water temperature is not limited to the release temperature. In step S140, the tap water temperature can also be compared with other indices that can determine whether or not the temperature is at a temperature at which hydrogen can be released from the storage alloy tank 16. [Explanation of symbols]

[0123] 10 Hydrogen Systems 13 Water electrolysis equipment 15 Dehumidifier 16. Storage alloy tank

Claims

1. a water electrolysis unit capable of producing hydrogen by electrolyzing water; a dehumidification unit for removing moisture contained in the hydrogen produced by the water electrolysis unit; a storage unit for storing hydrogen from which moisture has been removed by the dehumidification unit; Equipped with The water electrolysis unit is configured to perform a supply process for supplying heat generated in one of the water electrolysis unit, the dehumidification unit, and the storage unit to another of the water electrolysis unit, the dehumidification unit, and the storage unit. Hydrogen system.

2. The storage unit includes: The hydrogen is cooled when stored and heated when released. The supply process includes: A first process is performed when hydrogen produced by the operation of the water electrolysis unit and the dehumidification unit is stored in the storage unit, and a second process is performed when the hydrogen stored in the storage unit is released. The hydrogen system of claim 1 .

3. The first process includes: A first water utilization treatment system supplies heat generated in the one device to the other device using water as a heat medium; The hydrogen system of claim 2.

4. The first water use treatment is A process of supplying heat generated in at least one of the water electrolysis unit and the storage unit to the dehumidification unit. The hydrogen system of claim 3.

5. In the first water use treatment, When the temperature of the water is lower than a first threshold value based on a temperature at which hydrogen can be stored in the storage unit, heat generated in the storage unit is supplied to the dehumidification unit.

5. The hydrogen system of claim 4.

6. In the first water use treatment, Hydrogen is produced in the water electrolysis unit by using the water used as a heat medium. A hydrogen system according to any one of claims 3 to 5.

7. The first process includes: A first air utilization process supplies heat generated in at least one of the water electrolysis unit and the storage unit to the dehumidification unit using air as a heat medium. A hydrogen system according to any one of claims 2 to 5.

8. The second process includes: A second air utilization process is included in which heat generated in at least one of the water electrolysis unit and the dehumidification unit is supplied to the storage unit using air as a heat medium. The hydrogen system of claim 2.

9. The second process includes: and a second water utilization process for heating the storage unit using the water as a heat medium when the temperature of the water is higher than a second threshold based on a temperature at which hydrogen can be released from the storage unit. The hydrogen system of claim 2.

10. The second process includes: a second water usage process for heating the storage unit using the water as a heat medium when the temperature of the water is higher than a second threshold based on a temperature at which hydrogen can be released from the storage unit; and a waste heat utilization process for heating the storage unit using waste heat generated when a fuel cell generates electricity using hydrogen in the storage unit when the storage unit is to be further heated after the second air utilization process and the second water utilization process are performed; Including, 9. The hydrogen system of claim 8.

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