Hydrogen supply system

Abstract

To reliably supply hydrogen to a hydrogen utilization device at the startup of the hydrogen utilization device.SOLUTION: A hydrogen supply system O includes: hydrogen storage alloys 11A, 11B that store hydrogen to be supplied to a hydrogen utilization device C; a flow passage 52 connected to the hydrogen storage alloys 11A, 11B and the hydrogen utilization device C; a hydrogen tank 70 for storing hydrogen supplied from the flow passage 52 and supplying hydrogen to the hydrogen utilization device C at the startup of the hydrogen utilization device C; a flow passage 72 connected to the flow passage 52 and the hydrogen tank 70 for supplying hydrogen from the flow passage 52 to the hydrogen tank 70: a flow passage 73 connected to the flow passage 52 and the hydrogen tank 70 for supplying hydrogen from the hydrogen tank 70 to the flow passage 52; a check valve 75 provided in the flow passage 73 for blocking the flow of hydrogen from the hydrogen tank 70 to the flow passage 52; and an opening / closing valve 76 which is provided in the flow passage 73 and opens at the startup of the hydrogen utilization device C to supply hydrogen from the hydrogen tank 70 to the flow passage 52.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Patent document 1 discloses a hydrogen supply system including a hydrogen storage alloy container in which a hydrogen storage alloy is housed, a heat medium flow path through which a heat medium moves to transfer heat to the hydrogen storage alloy, and a temperature adjustment unit that adjusts the temperature of the heat medium moving in the heat medium flow path. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-35479 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the invention described in Patent Document 1, water (heat medium) in a water tank is heated by a heater, and the hydrogen storage alloy is heated by the heated water, thereby desorbing hydrogen from the hydrogen storage alloy.

[0005] However, in the invention described in Patent Document 1, for example, when starting up a fuel cell (hydrogen utilization device), if a power outage or other condition occurs that makes it impossible to secure a power source to operate the heater, the hydrogen storage alloy cannot be heated. As a result, hydrogen cannot be supplied to the fuel cell, and there is a risk that the fuel cell cannot be started.

[0006] An object of the present invention is to supply hydrogen to a hydrogen utilization device at the start of the hydrogen utilization device without receiving an external power supply. [Means for solving the problem]

[0007] The present invention comprises a hydrogen storage alloy that absorbs hydrogen to be supplied to a hydrogen utilization device, a first supply flow path connected to the hydrogen storage alloy and the hydrogen utilization device and supplying hydrogen desorbed from the hydrogen storage alloy to the hydrogen utilization device, a storage container that stores hydrogen supplied from the first supply flow path and supplies hydrogen to the hydrogen utilization device when the hydrogen utilization device is started up, a first connection flow path connected to the first supply flow path and the storage container and supplying hydrogen from the first supply flow path to the storage container, a second connection flow path connected to the first supply flow path and the storage container and supplying hydrogen from the storage container to the first supply flow path, a check valve provided in the first connection flow path to prevent hydrogen from flowing from the storage container to the first supply flow path, and a supply valve provided in the second connection flow path that opens when the hydrogen utilization device is started up to supply hydrogen from the storage container to the first supply flow path. Effect of the Invention

[0008] According to the present invention, hydrogen can be supplied to the hydrogen utilization device at the start of the hydrogen utilization device without receiving power from an external source. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram of a hydrogen energy system S to which a hydrogen supply system according to an embodiment of the present invention is applied. [Diagram 2] FIG. 2 is a characteristic diagram showing the relationship between the amount of hydrogen stored in the hydrogen storage alloy according to the embodiment of the present invention and the pressure inside the hydrogen storage tank. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] The hydrogen supply system O supplies hydrogen to a generator or driving source that uses hydrogen gas as fuel and is installed or mounted in a building or mobility, and absorbs or releases hydrogen gas generated by a hydrogen generation device P. First, a hydrogen energy system S to which the hydrogen supply system O according to an embodiment of the present invention is applied will be briefly described with reference to Fig. 1.

[0012] As shown in FIG. 1, the hydrogen energy system S includes a hydrogen supply system O, a hydrogen generation device P that supplies hydrogen to the hydrogen supply system O, and a hydrogen utilization device C that utilizes the hydrogen released from the hydrogen supply system O.

[0013] The hydrogen generation device P generates hydrogen by electrolyzing water. The hydrogen generation device P is equipped with a temperature regulator (not shown) that regulates the temperature of the generated hydrogen, and a pressure regulator (not shown) that regulates the pressure of the generated hydrogen.

[0014] The hydrogen utilization device C is an energy generation source that produces energy through a chemical reaction of hydrogen released from the hydrogen supply system O. Specifically, the energy generation source is a fuel cell or a hydrogen engine. A fuel cell produces electrical energy by reacting hydrogen released from the hydrogen supply system O with oxygen, and a hydrogen engine produces rotational energy by burning the hydrogen released from the hydrogen supply system O. The fuel cell and hydrogen engine emit heat and water or water vapor.

[0015] The hydrogen supply system O includes hydrogen storage alloys 11A, 11B for storing hydrogen, hydrogen storage tanks 10A, 10B in which the hydrogen storage alloys 11A, 11B are respectively housed, circulation circuits 20A, 20B in which water (fluid) circulates and which exchanges heat with the hydrogen storage alloys 11A, 11B, a cooling mechanism 30 that cools the water flowing through the circulation circuits 20A, 20B, and heating mechanisms 40A, 40B that heat the water flowing through the circulation circuits 20A, 20B.

[0016] The hydrogen storage tanks 10A, 10B are connected to the hydrogen generation device P by flow paths 51A, 51B, respectively, and are connected to the hydrogen utilization device C by flow paths 52A, 52B, respectively. In other words, the hydrogen storage tanks 10A, 10B are provided in parallel in the flow path connecting the hydrogen generation device P and the hydrogen utilization device C.

[0017] The flow paths 51A, 51B are provided with on-off valves 53A, 53B for opening or closing the flow paths 51A, 51B, and the flow paths 52A, 52B are provided with on-off valves 54A, 54B for opening or closing the flow paths 52A, 52B. The operation of the on-off valves 53A, 53B and the on-off valves 54A, 54B is controlled by a controller 60. In the following, the entire flow path connecting the hydrogen generation device P and the hydrogen storage tanks 10A, 10B, i.e., the flow paths 51A, 51B, is referred to as a flow path 51 (second supply flow path), and the entire flow path connecting the hydrogen storage tanks 10A, 10B and the hydrogen utilization device C, i.e., the flow paths 52A, 52B, is referred to as a flow path 52 (first supply flow path).

[0018] The hydrogen supply system O further includes a hydrogen tank 70 (storage container) for storing hydrogen supplied from the hydrogen generation device P and hydrogen desorbed from the hydrogen storage alloys 11A, 11B.

[0019] Hydrogen tank 70 is a high-pressure container that stores high-pressure hydrogen. Hydrogen tank 70 is connected to flow path 51 upstream of on-off valves 53A, 53B through flow path 71 (third connection flow path). Hydrogen tank 70 is also connected to flow path 52 downstream of on-off valves 54A, 54B through flow path 72 (first connection flow path) and flow path 73 (second connection flow path). Flow path 72 is connected to flow path 52 upstream of its connection point with flow path 73.

[0020] An on-off valve 74 that opens or closes the flow path 71 is provided in the flow path 71. The operation of the on-off valve 74 is controlled by the controller 60.

[0021] A compressor 80 and a check valve 75 are provided in the flow path 72. The compressor 80 compresses the hydrogen flowing through the flow path 52 and supplies the hydrogen to the hydrogen tank 70. The operation of the compressor 80 is controlled by the controller 60.

[0022] The check valve 75 is provided downstream of the compressor 80 in the flow path 72 , and prevents hydrogen from flowing back from the hydrogen tank 70 to the compressor 80 and the flow path 52 .

[0023] The flow path 73 is provided with an on-off valve 76 (supply valve) that opens or closes the flow path 73. The operation of the on-off valve 76 is controlled by the controller 60.

[0024] A check valve 77 is provided in flow path 52 downstream of the connection point with flow path 72 and upstream of the connection point with flow path 73. In addition, a pressure reducing valve 56 is provided in flow path 52 downstream of the connection point with flow path 73. The set pressure of the pressure reducing valve 56 is controlled by the controller 60. The pressure reducing valve 56 reduces the pressure of hydrogen supplied through flow path 52 (to, for example, about 0.15 MPa (G)) and supplies it to the hydrogen utilization device C.

[0025] Next, the hydrogen storage tanks 10A, 10B, the circulation circuits 20A, 20B, and the heating mechanisms 40A, 40B will be described. Since the hydrogen storage tanks 10A, 10B, the circulation circuits 20A, 20B, and the heating mechanisms 40A, 40B have the same configuration, the following description will focus on the hydrogen storage tank 10A, the circulation circuit 20A, and the heating mechanism 40A, and the hydrogen storage tank 10B, the circulation circuit 20B, and the heating mechanism 40B will be omitted by assigning the same numerals to the configurations of the hydrogen storage tank 10A, the circulation circuit 20A, and the heating mechanism 40B in the drawings that are the same as those of the hydrogen storage tank 10A, the circulation circuit 20A, and the heating mechanism 40A. The configurations of the hydrogen storage tank 10A, the circulation circuit 20A, and the heating mechanism 40A will be distinguished by adding "A" to the reference numerals, and the configurations of the hydrogen storage tank 10B, the circulation circuit 20B, and the heating mechanism 40B will be distinguished by adding "B" to the reference numerals.

[0026] The hydrogen storage tank 10A is composed of a pressure vessel, and a hydrogen storage alloy 11A is accommodated inside the hydrogen storage tank 10A. As the hydrogen storage alloy 11A, AB5 type, AB2 type, A2B type, solid solution type (BCC alloy), etc. can be used.

[0027] A pressure sensor 55A is provided downstream of the on-off valve 53A in the flow path 51A. The pressure sensor 55A detects the pressure around the hydrogen storage alloy 11A (the hydrogen pressure in the hydrogen storage tank 10A). The pressure sensor 55A may be provided upstream of the on-off valve 54A in the flow path 52A.

[0028] In the hydrogen energy system S, hydrogen generated by the hydrogen generation device P is supplied to the hydrogen storage tank 10A through the flow path 51A (flow path 51) by opening the on-off valve 53A. In addition, the supply of hydrogen generated by the hydrogen generation device P to the hydrogen storage tank 10A is cut off by closing the on-off valve 53A.

[0029] Furthermore, in the hydrogen energy system S, by opening the on-off valve 54A, hydrogen in the hydrogen storage tank 10A is supplied to the hydrogen utilization device C through the flow path 52A (flow path 52) and the pressure reducing valve 56. By closing the on-off valve 54A, the supply of hydrogen in the hydrogen storage tank 10A to the hydrogen utilization device C is cut off.

[0030] Next, the circulation circuit 20A will be described.

[0031] The circulation circuit 20A circulates water and exchanges heat with the hydrogen storage alloy 11A, thereby adjusting the temperature of the hydrogen storage alloy 11A.

[0032] As shown in FIG. 1, the circulation circuit 20A further includes a pump 21A for circulating water within the circulation circuit 20A, a first heat exchange unit 22A that performs heat exchange with the heating mechanism 40A, a second heat exchange unit 23A that performs heat exchange with the hydrogen storage alloy 11A, a cooling mechanism 30 that cools the water flowing within the circulation circuit 20A, a bypass flow path 24A that bypasses the cooling mechanism 30, a control valve 25A that controls the distribution of the flow rate to the cooling mechanism 30 and the bypass flow path 24A, a first temperature sensor 26A that detects the water temperature on the inlet side of the second heat exchange unit 23A, and a second temperature sensor 27A that detects the water temperature on the outlet side of the second heat exchange unit 23A.

[0033] The pump 21A is driven by a motor (not shown). The type of the pump 21A is not particularly limited, but the pump 21A may be a centrifugal pump, a gear pump, a vane pump, or the like.

[0034] The first heat exchange unit 22A exchanges heat with the heating mechanism 40A and receives heat from the heating mechanism 40A to heat the water circulating in the circulation circuit 20A.

[0035] The second heat exchange section 23A exchanges heat with the hydrogen storage alloy 11A to adjust the temperature of the hydrogen storage alloy 11A.

[0036] The control valve 25A distributes the water that has passed through the second heat exchange section 23A to the cooling mechanism 30 and the bypass flow path 24A. Specifically, the control valve 25A is configured as a three-way valve. The control valve 25A is controlled by the controller 60, and controls the flow rate of the water distributed to the cooling mechanism 30 and the bypass flow path 24A. In this embodiment, the control valve 25A is configured as a three-way valve, but the control valve 25A may be configured as two two-way valves.

[0037] The cooling mechanism 30 is composed of a chiller, a cooling tower, a radiator, etc. The cooling mechanism 30 may be any mechanism as long as it has at least a function as a radiator that releases heat of the water circulating in the circulation circuit 20A to the atmosphere.

[0038] In this embodiment, one cooling mechanism 30 cools the water circulating in the circulation circuits 20A and 20B. In other words, in this embodiment, the cooling mechanism 30 is common to the circulation circuits 20A and 20B, but the cooling mechanism 30 may be provided separately in the circulation circuits 20A and 20B.

[0039] The heating mechanism 40A includes a circulation circuit 41A through which water circulates as a heat medium, a pump 42 for circulating the water within the circulation circuit 41A, a third heat exchange unit 43A provided in the circulation circuit 41A and performing heat exchange with the first heat exchange unit 22A, a fourth heat exchange unit 44 provided in the circulation circuit 41A and performing heat exchange with the hydrogen utilization device C, and an on-off valve 45A provided between the pump 42 and the third heat exchange unit 43A in the circulation circuit 41A and for allowing or blocking the flow of water from the pump 42 to the third heat exchange unit 43A.

[0040] The circulation circuit 41A transfers the exhaust heat generated in the hydrogen utilization device C to the circulation circuit 20A by circulating the water therein.

[0041] The pump 42 is driven by a motor (not shown). There is no particular limitation on the type of the pump 42, but the pump 42 may be a centrifugal pump, a gear pump, a vane pump, or the like.

[0042] The third heat exchange section 43A exchanges heat with the first heat exchange section 22A, and heats the water circulating in the circulation circuit 20A with the heat of the water circulating in the circulation circuit 41A.

[0043] The fourth heat exchange section 44 exchanges heat with the hydrogen utilization device C, and heats the water circulating in the circulation circuit 41A with exhaust heat generated when the hydrogen utilization device C is driven.

[0044] In this manner, the heating mechanism 40A utilizes the exhaust heat generated when the hydrogen utilization device C is driven to heat the water circulating within the circulation circuit 41A.

[0045] In this embodiment, one pump 42 circulates the water in the circulation circuits 41A and 41B, and one fourth heat exchange section 44 heats the water circulating in the circulation circuits 41A and 41B. In other words, in this embodiment, the pump 42 and the fourth heat exchange section 44 are common to the circulation circuits 41A and 41B, but the pump 42 and the fourth heat exchange section 44 may be provided individually in the circulation circuits 41A and 41B, respectively.

[0046] Next, the adsorption and desorption of hydrogen in the hydrogen storage alloy 11A will be described with reference to Fig. 2. Fig. 2 is a graph showing the relationship between the pressure, temperature, and amount of hydrogen absorbed in the hydrogen storage alloys 11A and 11B (hydrogen storage tanks 10A and 10B). Note that the solid line in Fig. 2 shows the characteristics during adsorption, and the dotted line shows the characteristics during desorption.

[0047] First, the adsorption of hydrogen into the hydrogen storage alloy 11A will be described. Hydrogen generated by the hydrogen generation device P is guided into the hydrogen storage tank 10A through the flow path 51A by opening the on-off valve 53A. In this embodiment, the pressure of the hydrogen supplied from the hydrogen generation device P is about 0.8 MPa. The hydrogen guided into the hydrogen storage tank 10A is adsorbed by the hydrogen storage alloy 11A. When the hydrogen storage alloy 11A adsorbs hydrogen, the temperature of the hydrogen storage alloy 11A rises due to an exothermic reaction.

[0048] As shown in Fig. 2, the hydrogen storage alloy 11A absorbs less water at the same pressure as the temperature increases. Therefore, in this embodiment, the pump 21A is driven during absorption to circulate the water in the circulation circuit 20A. In this embodiment, the pump 21A is driven so that the discharge flow rate is constant.

[0049] The water discharged from the pump 21A cools the hydrogen storage alloy 11A in the second heat exchanger 23A. The water (which has passed through the second heat exchanger 23A) whose temperature has increased by heat exchange with the hydrogen storage alloy 11A is guided to the cooling mechanism 30 through the control valve 25A. In the cooling mechanism 30, the heat of the water passing through is removed, and the temperature of the water is reduced. The water cooled by the cooling mechanism 30 is guided to the pump 21A and discharged from the pump 21A again. By circulating the water in the circulation circuit 20A in this way, the heat generated by the hydrogen storage alloy 11A can be released to the outside. During adsorption, the pump 42 of the heating mechanism 40A is stopped or the opening / closing valve 45A is closed, so that heat exchange is not performed in the first heat exchanger 22A. As a result, the water in the circulation circuit 20A is not heated.

[0050] In this embodiment, when hydrogen is adsorbed by the hydrogen storage alloy 11A, the hydrogen pressure is controlled to be constant at about 0.8 MPa. Specifically, when the hydrogen pressure detected by the pressure sensor 55A decreases, the controller 60 controls the control valve 25A to guide a portion of the water that has passed through the second heat exchanger 23A to the bypass flow path 24A. As a result, the water guided to the bypass flow path 24A is discharged again from the pump 21A without passing through the cooling mechanism 30, i.e., without being cooled.

[0051] If the hydrogen storage alloy 11A is cooled too strongly, that is, if the temperature of the water passing through the second heat exchanger 23A is too low, the temperature of the hydrogen drops, and as a result, the hydrogen pressure drops. Therefore, a part of the water that has passed through the second heat exchanger 23A is led to the bypass flow passage 24A to bypass the cooling mechanism 30, thereby increasing the temperature of the water led to the second heat exchanger 23A. In this way, when the hydrogen pressure drops, the hydrogen pressure can be maintained at a constant pressure by suppressing the cooling of the hydrogen storage alloy 11A. Note that, for this control, the relationship between the hydrogen pressure and the opening degree of the control valve 25A (the amount of flow rate distributed to the cooling mechanism 30 and the bypass flow passage 24A) is obtained in advance by experiments or the like, and these relationships are stored in the controller 60, and the control is performed based on the stored relationship. Feedback control may also be performed based on the pressure detected by the pressure sensor 55A. Alternatively, control may be performed using the first temperature sensor 26A and the second temperature sensor 27A provided in the circulation circuit 20A, or control may be performed using a combination of the pressure sensor 55A, the first temperature sensor 26A, and the second temperature sensor 27A.

[0052] The adsorption by the hydrogen storage alloy 11A is terminated by closing the on-off valve 53A.

[0053] Next, desorption of hydrogen from the hydrogen storage alloy 11A will be described. Hydrogen in the hydrogen storage tank 10A is led to the hydrogen utilization device C through a flow path 52A by opening an on-off valve 54A.

[0054] When the hydrogen utilization device C starts up, the controller 60 desorbs hydrogen from the hydrogen storage alloy 11A to supply hydrogen to the hydrogen utilization device C. Specifically, the controller 60 first opens the on-off valve 54A. This allows hydrogen to be supplied from the hydrogen storage tank 10A to the hydrogen utilization device C. In this embodiment, the pressure of the hydrogen desorbed from the hydrogen storage alloy 11A is controlled to be constant at about 0.8 MPa.

[0055] When the hydrogen storage alloy 11A desorbs hydrogen, the temperature of the hydrogen storage alloy 11A drops due to an endothermic reaction. When the temperature of the hydrogen storage alloy 11A drops, the pressure of the hydrogen desorbed from the hydrogen storage alloy 11A drops, and the hydrogen stops being desorbed. Therefore, in this embodiment, the heating mechanism 40A is driven to heat the water circulating in the circulation circuit 20A, thereby heating the hydrogen storage alloy 11A.

[0056] Specifically, the controller 60 drives the pump 42 and opens the on-off valve 45A. The controller 60 also drives the pump 21A and controls the control valve 25A so that the entire amount of water circulating in the circulation circuit 20A passes through the bypass flow path 24A. As a result, the water in the circulation circuit 41A circulates, and the water in the circulation circuit 20A circulates while bypassing the cooling mechanism 30.

[0057] The water circulating in the circulation circuit 41A exchanges heat with the hydrogen utilization device C in the fourth heat exchange section 44, and is heated by the exhaust heat of the hydrogen utilization device C. When the water heated in the fourth heat exchange section 44 reaches the third heat exchange section 43A, heat exchange occurs between the third heat exchange section 43A and the first heat exchange section 22A, and the water circulating in the circulation circuit 20A is heated. In this manner, in this embodiment, the hydrogen storage alloy 11A is heated using the exhaust heat of the hydrogen utilization device C. The circulation circuits 20A, 20B and the heating mechanisms 40A, 40B in this embodiment correspond to the "heat exchange device" in the claims.

[0058] If the temperature of the water circulating in the circulation circuit 20A becomes too high, the pressure of the hydrogen desorbed from the hydrogen storage alloy 11A increases. In this case, the controller 60 controls the on-off valve 45A to reduce the flow rate of the water passing through the third heat exchange section 43A. This reduces the amount of heat received by the first heat exchange section 22A from the third heat exchange section 43A, thereby suppressing the temperature rise of the water circulating in the circulation circuit 20A. This control is performed by performing feedback control based on the pressure detected by the pressure sensor 55A.

[0059] When the temperature of the water circulating in the circulation circuit 20A becomes too high, in addition to controlling the on-off valve 45A, the control valve 25A may be controlled so that a part of the water circulating in the circulation circuit 20A passes through the cooling mechanism 30. The water that has passed through the cooling mechanism 30 is cooled by the cooling mechanism 30 and merges with the water that has passed through the bypass flow path 24A. This makes it possible to lower the temperature of the water circulating in the circulation circuit 20A. Alternatively, only the control valve 25A may be controlled. Furthermore, the control may be performed using the first temperature sensor 26A and the second temperature sensor 27A provided in the circulation circuit 20A, or the control may be performed using the pressure sensor 55A in combination with the first temperature sensor 26A and the second temperature sensor 27A.

[0060] In the hydrogen energy system S, the hydrogen supply system O includes two hydrogen storage tanks 10A, 10B. Therefore, when one of the hydrogen storage alloys 11A, 11B of the hydrogen storage tanks 10A, 10B is desorbing hydrogen, the other hydrogen storage alloy 11A, 11B can adsorb hydrogen. This allows a stable supply of hydrogen to the hydrogen utilization device C. The number of hydrogen storage tanks may be three or more, or may be one as long as the requirements for the hydrogen energy system S are met.

[0061] However, for example, if the hydrogen utilization device C has been stopped for a long period of time, there is a risk that it will not be possible to heat the hydrogen storage alloys 11A, 11B because no exhaust heat is generated from the hydrogen utilization device C. Therefore, it is conceivable to provide a heat generating device such as a heater and use the heat generated by the heat generating device when the hydrogen utilization device C is started up to heat the hydrogen storage alloys 11A, 11B and desorb hydrogen from the hydrogen storage alloys 11A, 11B.

[0062] However, even if a heating device such as a heater is provided, if a power outage or other event occurs that makes it impossible to secure a power source to operate the heater, it may be impossible to heat the hydrogen storage alloys 11A and 11B and therefore impossible to desorb hydrogen from the hydrogen storage alloys 11A and 11B. As a result, hydrogen may not be supplied to the hydrogen utilization device C, and the hydrogen utilization device C may not be able to start up.

[0063] Therefore, in the hydrogen supply system O of the present embodiment, the hydrogen tank 70 is provided so as to be able to supply hydrogen to the hydrogen utilization device C without using electric power. The specific operation of the hydrogen tank 70 will be described below.

[0064] When starting up the hydrogen utilization device C, the on-off valve 76 is opened. This causes hydrogen stored in the hydrogen tank 70 to be supplied to the hydrogen utilization device C through the flow path 73 and the flow path 52. The on-off valve 76 is an electrically operated valve that is opened and closed in response to instructions from the controller 60. Since the on-off valve 76 uses a small amount of power, it can be operated by receiving power from an emergency power source such as a battery even during a power outage. However, since the heater uses a large amount of power, it cannot be operated by a battery or the like.

[0065] In this way, since the hydrogen supply system O is provided with the hydrogen tank 70, the hydrogen utilization device C can be started even in a situation where the hydrogen storage alloys 11A, 11B cannot be heated, specifically, in a situation where no power supply can be received from the outside. Once the hydrogen utilization device C is started, it becomes possible to generate power and to utilize the exhaust heat of the hydrogen utilization device C. This makes it possible to execute normal control.

[0066] As shown in FIG. 1, in the hydrogen supply system O, a check valve 77 is provided in the flow path 52, so that when the on-off valve 76 is opened to supply hydrogen from the hydrogen tank 70 to the hydrogen utilization device C, hydrogen discharged from the hydrogen tank 70 does not flow into the hydrogen storage tanks 10A, 10B or the flow path 72.

[0067] Next, a method for filling the hydrogen tank 70 with hydrogen will be described.

[0068] The hydrogen tank 70 is filled with hydrogen generated by the hydrogen generation device P or hydrogen desorbed from the hydrogen storage alloys 11A, 11B.

[0069] The decision as to whether or not to fill the hydrogen tank 70 with hydrogen generated by the hydrogen generation device P is made by the controller 60. The controller 60 decides whether or not it is necessary to fill the hydrogen tank 70 with hydrogen generated by the hydrogen generation device P based on the pressure inside the hydrogen tank 70 and the pressure upstream of the on-off valve 74 in the flow path 71, and if it is determined that filling is necessary, it opens the on-off valve 74. As a result, the hydrogen generated by the hydrogen generation device P is guided into the hydrogen tank 70 through the flow path 71 and the on-off valve 74, and is stored in the hydrogen tank 70.

[0070] 1, flow path 71 is provided with on-off valve 74, but instead of on-off valve 74, a check valve that allows only flow from hydrogen generation device P to hydrogen tank 70 may be provided. In this case, when the pressure upstream of check valve in flow path 71 is greater than the pressure inside hydrogen tank 70, hydrogen is automatically filled into hydrogen tank 70.

[0071] When hydrogen desorbed from the hydrogen storage alloys 11A, 11B is to be filled into the hydrogen tank 70, the compressor 80 is driven. The decision as to whether or not to fill the hydrogen tank 70 with hydrogen desorbed from the hydrogen storage alloys 11A, 11B is made by the controller 60. When hydrogen is being desorbed from the hydrogen storage alloys 11A, 11B, the controller 60 makes a decision as to whether or not to fill the hydrogen tank 70 with hydrogen desorbed from the hydrogen storage alloys 11A, 11B based on the pressure in the hydrogen tank 70 and the pressure in the flow path 52, and drives the compressor 80 if it is decided to fill the hydrogen tank 70.

[0072] By using the compressor 80, it is possible to fill the hydrogen tank 70 with more hydrogen even when the pressure in the flow path 52 is lower than the pressure in the hydrogen tank 70. Note that, for example, if the amount of hydrogen required for starting the hydrogen utilization device C can be secured by directly filling the hydrogen tank 70 with hydrogen in the flow path 52, then the compressor 80 does not need to be provided.

[0073] Specifically, as is clear from Fig. 2, even if the hydrogen storage alloys 11A and 11B have the same hydrogen storage capacity, the hydrogen pressure differs when the temperatures of the hydrogen storage alloys 11A and 11B are different. It is also clear that there is a region in which the hydrogen storage capacity changes significantly even at the same temperature.

[0074] In the hydrogen storage alloys 11A, 11B of this embodiment, when the temperature is around 60° C., the hydrogen pressure during adsorption and desorption is 0.8 MPa (A) or more. On the other hand, the pressure of hydrogen supplied to the hydrogen utilization device C of this embodiment is about 0.15 MPa (G). For this reason, when the hydrogen storage alloys 11A, 11B are operated at a temperature of around 60° C., it is not necessary to increase the pressure by the compressor 80 when filling the hydrogen tank 70 with hydrogen from the hydrogen storage alloys 11A, 11B. In other words, when such high-pressure hydrogen is desorbed, the compressor 80 does not need to be provided.

[0075] In contrast, when the hydrogen storage alloys 11A, 11B are operated at around 20° C., the hydrogen pressure during adsorption and desorption is about 0.2 MPa. For this reason, in order to supply a sufficient amount of hydrogen at the start-up of the hydrogen utilization device C, it is desirable to compress (increase the pressure of) the hydrogen stored in the hydrogen tank 70 by the compressor 80.

[0076] In addition, if compressor 80 is not provided, when the pressure upstream of check valve 77 in flow path 52, i.e., the pressure of hydrogen supplied to flow path 52 from hydrogen storage tanks 10A, 10B, is greater than the pressure inside hydrogen tank 70, hydrogen is automatically supplied from flow path 52 through check valve 77 into hydrogen tank 70.

[0077] The hydrogen supply system O configured as above provides the following advantages.

[0078] According to the hydrogen supply system O of this embodiment, hydrogen can be reliably supplied to the hydrogen utilization device C without receiving power supply from an external source. This allows the hydrogen utilization device C to be started reliably.

[0079] Furthermore, in the hydrogen supply system O, even if the hydrogen in the hydrogen tank 70 is consumed, the hydrogen flowing through the flow path 51 or the flow path 52 can be used to refill the hydrogen tank 70. This eliminates the need to refill the hydrogen tank 70 with hydrogen or to replace the hydrogen tank 70. Furthermore, no special equipment is required to refill the hydrogen tank 70 with hydrogen, which helps prevent costs from increasing.

[0080] Furthermore, in the hydrogen supply system O, the compressor 80 is used to compress hydrogen and fill it into the hydrogen tank 70. This allows a larger amount of hydrogen to be stored in the hydrogen tank 70, so that a larger amount of hydrogen can be supplied when the hydrogen utilization device C is started up. This allows the hydrogen utilization device C to be started up more reliably.

[0081] Furthermore, in the hydrogen supply system O, the hydrogen storage alloys 11A, 11B are heated by the exhaust heat generated by the operation of the hydrogen utilization device C, so that the energy efficiency can be improved.

[0082] As described above, by providing the hydrogen supply system O, it is possible to start up the hydrogen utilization device C to generate power without receiving power from an external source. Therefore, the hydrogen energy system S can be used as an emergency power generation facility, more specifically, as an emergency power generation facility for avoiding, for example, a power outage in the power grid.

[0083] Although the embodiments of the present invention have been described above, the above-mentioned embodiments merely show some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above-mentioned embodiments.

[0084] In the above embodiment, the operation of the on-off valve 76 is controlled by the controller 60, but the on-off valve 76 may be manually operated. Also, instead of the on-off valve 76, a pressure reducing valve (supply valve) may be provided.

[0085] In the above embodiment, the hydrogen tank 70 can be filled with hydrogen from the flow path 51, but the flow path 71 and the on-off valve 74 do not have to be provided if they are not required.

[0086] In the above embodiment, the heating mechanisms 40A, 40B are described as being configured to heat the water flowing through the circulation circuits 41A, 41B using exhaust heat from the hydrogen utilization device C, but the present invention is not limited to this. The heating mechanisms 40A, 40B may be heaters that directly heat the water circulating in the circulation circuits 20A, 20B. In addition, if a chiller or the like capable of heating and cooling the water circulating in the circulation circuits 20A, 20B is provided, the heating mechanisms 40A, 40B may not be provided. From the viewpoint of energy saving, it is preferable to employ the heating mechanisms 40A, 40B that utilize exhaust heat generated in the hydrogen utilization device C as in the above embodiment.

[0087] In the above embodiment, water has been described as an example of the fluid flowing through the circulation circuits 20A and 20B, but this is not limiting. When a radiator, chiller, or the like is used as the cooling mechanism 30, the circulation circuits 20A and 20B can be isolated from the outside, so that a fluid other than water can be used.

[0088] Furthermore, in the above embodiment, an example has been described in which pump 21A is driven so that the discharge flow rate is constant during adsorption, but this is not limiting, and the discharge flow rate of pump 21A may be changed in response to changes in the hydrogen pressure or temperature.

[0089] In the above embodiment, the pressure is controlled to be constant, but the pressure may be controlled to be within a predetermined range. In addition, if the cooling temperature can be lowered, the pressure during adsorption may be set lower than 0.8 MPa.

[0090] In the embodiment shown in FIG. 1 and the like, for convenience, the heat exchanger composed of the first heat exchange section 22A and the third heat exchange section 43A is described as a parallel flow type, and the heat exchanger composed of the first heat exchange section 22B and the third heat exchange section 43B is described as a counterflow type, but either the parallel flow type or the counterflow type can be used.

[0091] In the above embodiment, the hydrogen generation device P has been described as an electrolysis device that generates hydrogen by electrolyzing water. However, the hydrogen generation device P is not limited to a fixed device such as an electrolysis device, and may be a mobile device such as a hydrogen trailer. [Explanation of symbols]

[0092] S...Hydrogen Energy System P... Hydrogen generator O Hydrogen Supply System C Hydrogen Utilization Device 10A, 10B: Hydrogen storage tank 11A, 11B: Hydrogen storage alloy 20A,20B...Circulation circuit (heat exchange device) 30...Cooling mechanism 40A, 40B... Heating mechanism (heat exchange device) 51, 51A, 51B...flow path (second supply flow path) 52, 52A, 52B...flow path (first supply flow path) 60...Controller 70 Hydrogen tank (storage container) 71···Flow path (third connecting flow path) 72... Flow path (first connecting flow path) 73... Flow path (second connecting flow path) 75 Check valve 76...Shut-off valve (supply valve) 80···Compressor

Claims

1. a hydrogen storage alloy that stores hydrogen to be supplied to a hydrogen utilization device; a first supply flow passage connected to the hydrogen storage alloy and the hydrogen utilization device, for supplying hydrogen desorbed from the hydrogen storage alloy to the hydrogen utilization device; a storage container that stores hydrogen supplied from the first supply flow path and supplies hydrogen to the hydrogen utilization device when the hydrogen utilization device is started up; a first connection flow path connected to the first supply flow path and the storage container and configured to supply hydrogen from the first supply flow path to the storage container; a second connection flow path connected to the first supply flow path and the storage container and configured to supply hydrogen from the storage container to the first supply flow path; a check valve provided in the first connection flow path and configured to prevent hydrogen from flowing from the storage container to the first supply flow path; a supply valve provided in the second connection flow path and opening when the hydrogen utilization device is started to supply hydrogen from the storage container to the first supply flow path.

2. 2. The hydrogen supply system according to claim 1, The hydrogen supply system further comprises a compressor provided in the first connection flow path for compressing the hydrogen stored in the storage container.

3. 2. The hydrogen supply system according to claim 1, The hydrogen supply system further comprises a heat exchanger that heats the hydrogen storage alloy with exhaust heat generated by the operation of the hydrogen utilization device.

4. 2. The hydrogen supply system according to claim 1, a second supply flow path for supplying hydrogen to the hydrogen storage alloy; a third connection flow path connected to the second supply flow path and the storage container for supplying hydrogen from the second supply flow path to the storage container.

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