Hydrogen Generator

Abstract

To provide a hydrogen generator capable of improving accuracy in adjusting the temperature of water using a heat exchanger to improve the production efficiency of hydrogen gas in the hydrogen generator.SOLUTION: There is provided a hydrogen generator comprises an electrolysis device for electrolyzing water to generate hydrogen, a water circulation route in which water circulates via the electrolysis device, an ion exchanger for removing an ion in the water circulation route, and a water temperature adjustment device for adjusting the temperature of water flowing in the water circulation route. The water circulation route branches between the ion exchanger and the electrolysis device and subsequently merges, the water temperature adjustment device supplies the ion exchanger with water of a lower temperature than that of the water discharged from the electrolysis device, comprises a heat exchanger disposed between the branching point and the merging point so as to supply the electrolysis device with water of a higher temperature than that of the water of the low temperature, and comprises a temperature adjustment valve configured to provide the merging water merging at the merging point with a temperature difference to adjust the ratio of the merging water to adjust the temperature of the water to be supplied to the electrolysis device.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a hydrogen generating device, and more particularly to a hydrogen generating device equipped with an electrolysis device that generates hydrogen by electrolyzing water. [Background technology]

[0002] In recent years, opportunities to use hydrogen as a clean energy source have been increasing. Hydrogen generators that generate hydrogen by electrolyzing water are known as devices for obtaining hydrogen. One such hydrogen generator is equipped with a circulation path for circulating water through the electrolysis device, in which a larger amount of water than is electrolyzed is supplied to the anode side of an electrolysis device that electrolyzes water, a gas-liquid mixture containing oxygen gas and remaining water that has not been electrolyzed is discharged from the electrolysis device, the gas-liquid mixture is separated into water and oxygen in a gas-liquid separator, and the separated water is supplied again to the electrolysis device.

[0003] In this type of hydrogen generation device, an ion exchanger containing ion exchange resin is placed in the circulation path to capture ions eluted in the water in the device's piping, and the circulating water is passed through the ion exchanger to perform ion exchange. In a hydrogen generation device, the higher the water temperature, the higher the electrolysis efficiency in the electrolysis device, but passing high-temperature water through the ion exchanger will damage the ion exchange resin. For this reason, some hydrogen generation devices are known that include a water temperature adjustment device that cools the water before it passes through the ion exchanger and heats the water after it passes through the ion exchanger and before it is supplied to the electrolysis device (see Patent Documents 1 and 2 below). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2020-518719 [Patent Document 2] Special Publication No. 2023-529566 Summary of the Invention [Problem to be solved by the invention]

[0005] Heat exchangers, for example, are used as a means for heating or cooling water. While using electric heaters and the like requires relatively large amounts of energy, heat exchangers make it easy to utilize unused energy, such as low-temperature waste heat from other devices. Furthermore, using a heat exchanger allows the hot or cold energy obtained through heat exchange to be effectively utilized elsewhere. Therefore, the use of heat exchangers offers many advantages in terms of energy conservation. However, compared to water temperature adjustment using electric heaters and the like, temperature adjustment using a heat exchanger is less responsive and makes delicate temperature adjustment difficult. For example, large temporal fluctuations in the temperature of water supplied to an electrolysis device can make it difficult to sufficiently improve electrolysis efficiency, or the water may become too hot inside the electrolysis device, generating steam. Therefore, an objective of the present invention is to provide a hydrogen generation device that can improve the accuracy of water temperature adjustment using a heat exchanger, thereby improving the hydrogen gas production efficiency of the hydrogen generation device. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention provides: an electrolysis device that electrolyzes water to generate hydrogen; a water circulation path for circulating water through the electrolysis device; an ion exchanger for removing ions contained in the water flowing through the water circulation path; a water temperature adjusting device that adjusts the temperature of the water flowing through the water circulation path, The water temperature adjustment device is the system is configured to supply to the ion exchanger water having a lower temperature than the water discharged from the electrolysis device, and to supply to the electrolysis device water having a higher temperature than the water supplied to the ion exchanger, and includes one or more heat exchangers including a first heat exchanger that exchanges heat with the water that has passed through the ion exchanger upstream of the electrolysis device; The water circulation path is a first path from the ion exchanger through the first heat exchanger to the electrolyzer; a second path branching from the first path between the ion exchanger and the first heat exchanger and joining the first path between the first heat exchanger and the electrolysis device; a third path from the electrolysis device to the ion exchanger; The first pathway is the route has three sections separated by a branch point with the second route and a junction point with the second route, the three sections being composed of a first section upstream of the branch point, a second section after the branch point and upstream of the junction point, and a third section after the junction point; The water temperature adjustment device is The present invention provides a hydrogen generation device having a temperature control valve that adjusts the ratio between the amount of water flowing through the second section and the amount of water flowing through the second path to adjust the temperature of the water supplied to the electrolysis device. [Effects of the Invention]

[0007] In this invention, water whose temperature has been adjusted through a heat exchanger and water that has not passed through the heat exchanger are combined. Then, in this invention, the temperature of the combined water is adjusted by adjusting the ratio of the water that is combined using a temperature control valve. Therefore, in this invention, the accuracy of temperature adjustment can be improved compared to when temperature adjustment is performed using only a heat exchanger. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a hydrogen generation device according to a first embodiment. [Figure 2a] FIG. 2a is a schematic diagram showing one variation of the connection state between the first route and the second route at the branch point. [Figure 2b] FIG. 2b is a schematic diagram showing one variation (an embodiment different from FIG. 2a) of the connection state between the first path and the second path at the branch point. [Figure 2c] FIG. 2c is a schematic diagram showing one variation of the connection state between the first path and the second path at the branch point (an embodiment different from those in FIGS. 2a and 2b). [Figure 3]FIG. 3 is a schematic diagram showing the configuration of a hydrogen generation apparatus according to the second embodiment. [Figure 4] FIG. 4 is a schematic diagram showing a modified example of the hydrogen generation device according to the second embodiment. [Figure 5] FIG. 5 is a schematic diagram showing the configuration of a hydrogen generation apparatus according to the third embodiment. [Figure 6] FIG. 6 is a schematic diagram showing a modified example of the hydrogen generation device according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0010] (First embodiment) The hydrogen generation device 1 according to the first embodiment illustrated in Fig. 1 includes an electrolysis device 10 that electrolyzes water to generate hydrogen, a water circulation path CL for circulating water through the electrolysis device 10, and a pump CP for circulating water through the water circulation path CL. The water circulation path CL is provided with an ion exchanger 20 that removes ions contained in the water flowing through the water circulation path CL. The hydrogen generation device 1 according to the first embodiment also includes a water temperature adjustment device TC that adjusts the temperature of the water flowing through the water circulation path CL.

[0011] In the hydrogen generator 1 of this embodiment, the temperature of the water is adjusted using heat exchangers (first heat exchanger HX1, second heat exchanger HX2) and a temperature control valve TCV, as described below. In this embodiment, water that passes through at least one heat exchanger (first heat exchanger HX1) and water that does not pass through are combined, and the temperature control valve TCV adjusts the ratio of the combined water to adjust the temperature of the combined water. Therefore, in this embodiment, the temperature of the water in the ion exchanger 20 can be adjusted to be equal to or higher than the heat resistance temperature of the ion exchange resin, and the electrolysis efficiency of the electrolysis device 10 can be increased. In the figure, arrow C pointing toward the heat exchanger represents a cold medium, and arrow H pointing toward the heat exchanger represents a hot medium. Arrow H pointing away from the heat exchanger represents the cold medium being heated in the heat exchanger and discharged, and arrow C pointing away from the heat exchanger represents the hot medium being cooled in the heat exchanger and discharged.

[0012] The electrolysis device 10 includes an electrolysis device main body 11 having a plurality of electrolysis cells, each of which includes an anode chamber where oxygen gas is generated by electrolysis of water, a cathode chamber where hydrogen gas is generated, and a solid polymer electrolyte membrane that separates the cathode chamber from the anode chamber, and a power supply device 12 that supplies power to the electrolysis device main body 11.

[0013] The water circulation path CL in this embodiment is composed of multiple devices such as the electrolysis device 10 and piping connecting the devices, and the piping may be composed of pipes such as steel pipes or PVC pipes, joints such as elbows and tee pipes, and various valves.

[0014] The hydrogen generator 1 is configured to supply an amount of water in excess of the amount of water to be electrolyzed to the anode side of the electrolysis device main body 11, and to discharge a gas-liquid mixed fluid containing water that has not been electrolyzed and oxygen gas from the anode side. The hydrogen generator 1 has an anode-side gas-liquid separator 30 that separates the gas-liquid mixed fluid into gas and liquid. The anode-side gas-liquid separator 30 is disposed downstream of the electrolysis device 10 in the direction of water flow in the water circulation path CL, and upstream of the ion exchanger 20. The hydrogen generator 1 further includes a water supply system 40 for replenishing water consumed by electrolysis. The water supply system 40 is disposed outside the water circulation path CL and is provided to replenishing water to the water circulation path CL through the anode-side gas-liquid separator 30.

[0015] The water supply system 40 may include, for example, a water purifier that removes impurities from raw water such as tap water to improve the purity of the water. The water purifier may include a reverse osmosis (RO) filter, an activated carbon filter, or the like. In this embodiment, water may be supplied directly from the water purifier to the anode-side gas-liquid separator 30. Alternatively, if the water supply system 40 further includes, for example, a pure water reservoir that stores pure water obtained by the water purifier, water may be supplied to the anode-side gas-liquid separator 30 from the pure water reservoir. The pure water reservoir may include, for example, a pure water tank that stores pure water. That is, the water supply system 40 of this embodiment may be configured to supply water with improved purity to the anode-side gas-liquid separator 30 on-time, or may be configured to store the water with improved purity in the pure water tank during off-time when water is not being supplied. Note that the location where water is supplied from the water supply system 40 to the water circulation path CL is not limited to the anode-side gas-liquid separator 30, and may be another location.

[0016] The hydrogen generation device 1 has the water temperature adjustment device TC configured to supply the ion exchanger 20 with water having a lower temperature than the water discharged from the electrolysis device 10, and to supply the electrolysis device 10 with water having a higher temperature than the water supplied to the ion exchanger 20.

[0017] The water temperature adjustment device TC has one or more heat exchangers including a first heat exchanger HX1 that exchanges heat with the water that has passed through the ion exchanger 20 upstream of the electrolysis device 10. The water temperature adjustment device TC of this embodiment further has a second heat exchanger HX2 that exchanges heat with the water that flows between the electrolysis device 10 and the ion exchanger 20. The second heat exchanger HX2 in this embodiment is disposed downstream of the anode-side gas-liquid separator 30.

[0018] Each of the first heat exchanger HX1 and the second heat exchanger HX2 may be a liquid-liquid heat exchanger in which both substances in heat exchange are liquid, or a gas-liquid heat exchanger in which one substance is liquid and the other is gas. Each of the first heat exchanger HX1 and the second heat exchanger HX2 may be a plate-type heat exchanger, a multi-tube heat exchanger (shell-tube heat exchanger), or a fin-tube heat exchanger. In this embodiment, the first heat exchanger HX1 is used to heat water flowing through the water circulation path CL, and the second heat exchanger HX2 is used to cool water flowing through the water circulation path CL. Among the above, the plate-type heat exchanger is preferable in that it has excellent heat exchange efficiency and allows the temperature of the water after heat exchange to be easily adjusted by adjusting the flow rate.

[0019] The water circulation path CL includes a first path CL1 that runs from the ion exchanger 20 through the first heat exchanger HX1 to the electrolysis device 10, a second path CL2 that branches off from the first path CL1 between the ion exchanger 20 and the first heat exchanger HX1 and joins the first path CL1 between the first heat exchanger HX1 and the electrolysis device 10, and a third path CL3 that runs from the electrolysis device 10 to the ion exchanger 20.

[0020] In the water circulation pathway CL, the outlet of the ion exchanger 20 is the starting point of a first pathway CL1, and the inlet of the electrolysis device 10 is the end point of the first pathway CL1. In addition, in the water circulation pathway CL, the inlet of the electrolysis device 10 is the starting point of a third pathway CL3, and the outlet of the ion exchanger 20 is the end point of the third pathway CL3. The first pathway CL1 includes a branch point PS with a second pathway CL2 and a junction point PJ between the starting point and the end point. That is, the first pathway CL1 has three sections separated by the branch point PS and the junction point PJ, and the three sections are composed of a first pathway A1 upstream of the branch point PS, a second pathway A2 subsequent to the branch point PS and upstream of the junction point PJ, and a third pathway A3 subsequent to the junction point PJ.

[0021] Specifically, the branch point PS and the junction point PJ can be configured as T-shaped or Y-shaped. For example, when the branch point PS is configured as a T-shaped, a first section A1 and a second section A2 may extend from two of the three openings of the T-shaped, aligned in the straight direction, as shown in Figure 2a, and the second path CL2 may branch off in a direction intersecting with the first path CL1. When the branch point PS is configured as a T-shaped, the second section A2 may be connected to the first section A1 so as to intersect at a right angle, and the second path CL2 may branch off so as to extend in a straight direction following the first section A1, as shown in Figure 2b. Furthermore, when the branch point PS is configured as a T-shaped cheese, as shown in Figure 2c, the second section A2 and the second route CL2 may extend from two openings aligned in the straight-ahead direction of the T-shaped cheese, and the second section A2 and the second route CL2 may extend in a direction perpendicular to the extension direction of the first section A1. The same can be said for the junction point PJ in that the connection status between the first route CL1 and the second route CL2 can be freely set as described above.

[0022] In this embodiment, the flow of water passing through the water circulation path CL is divided into a first flow passing through the second section A2 and a second flow flowing through the second path midway through the first path CL1, and then a temperature difference is created between the first flow and the second flow in the first heat exchanger HX1, and the first flow and the second flow, which have different temperatures, are joined together to adjust the temperature of the water supplied to the electrolysis device 10.

[0023] The water temperature adjustment device TC has the temperature control valve TCV that adjusts the ratio between the amount of water flowing through the second section A2 and the amount of water flowing through the second path CL2, and adjusts the temperature of the water supplied to the electrolysis device 10. In this embodiment, the adjustment of the ratio (flow rate adjustment) by the temperature control valve TCV can preferably be based on any one of the following (a), (b), and (c). (a) The temperature of the water that joins at the joining point PJ and is supplied to the electrolysis device 10. (b) The temperature of each of the waters that meet at the junction PJ. (c) The temperature of the water discharged from the electrolysis device 10. The adjustment of the ratio (flow rate adjustment) by the temperature control valve TCV may be performed based on one or more of (a), (b), and (c).

[0024] Generally, the amount of heat exchanged in a heat exchanger varies depending on various factors, such as the flow rate, temperature difference, and specific heat of the two materials being heat exchanged through the heat exchanger. Therefore, it is difficult to accurately adjust the temperature of the water after passing through the first heat exchanger HX1 using only the first heat exchanger HX1. In particular, under operating conditions in which the electrolysis output fluctuates temporarily or constantly, it is difficult to accurately adjust the temperature of the water using only the first heat exchanger HX1. The water temperature adjustment device TC in this embodiment adjusts the ratio between the amount of water flowing through the first path CL1 and the amount of water flowing through the second path CL2 based on the aperture of the temperature control valve TCV. This allows the temperature of the water supplied to the electrolysis device 10 to be adjusted with minimal error from the target value and stably over time. For these reasons, the hydrogen generator 1 in this embodiment can adjust the water temperature with minimal error from the target value and stably over time, even when at least a portion of the power used for electrolysis is generated from renewable energy sources such as solar power and wind power, which have less stable power supply than grid power.

[0025] To more accurately adjust the temperature of the water supplied to the electrolysis device 10, it is more preferable that the temperature control valve TCV adjusts the proportion of water to be joined based on the temperature (a) of the water after joining. The temperature of the water after joining may be detected immediately after joining, at a midpoint between the joining point and the electrolysis device 10, or just before the inlet of the electrolysis device 10. The temperature of the water that joins at the joining point PJ and is supplied to the electrolysis device 10 may be detected within the electrolysis device 10, or may be detected immediately after flowing into the electrolysis device 10. In other words, the temperature of the water supplied to the electrolysis device 10 can be measured not only in any of the third section A3, but also in the third route CL3.

[0026] Regarding the temperature (b) of each of the waters joining at the junction PJ, it is preferable to measure the temperature of the water joining at the junction PJ from the first path CL1 (second section A2) side and the temperature of the water joining from the second path CL2 side at a position close to the junction PJ, preferably at a position closer to the junction PJ than the midpoint of the second path CL2, and at a position closer to the junction PJ than the midpoint between the first heat exchanger HX1 and the junction PJ, and more preferably just before the junction PJ. The temperature of the water joining from the second path CL2 side may be measured at a point before the midpoint of the second path CL2, or may be measured in the first path CL1 before the branch point PS, or if necessary, may be measured between the branch point PS and the first heat exchanger HX1.

[0027] The temperature (c) of the water discharged from the electrolysis device 10 may be measured in the anode-side gas-liquid separator 30, or may be measured upstream of the anode-side gas-liquid separator 30, or may be measured at a position closer to the electrolysis device 10 than a midpoint between the electrolysis device 10 and the anode-side gas-liquid separator 30. The temperature (c) of the water discharged from the electrolysis device 10 may be measured, for example, at a position where the water enters the electrolysis device 10 from the outlet of the electrolysis device 10.

[0028] In the hydrogen generator 1, the pump CP disposed in the water circulation path CL adjusts the flow rate of water, thereby adjusting the dynamic pressure of the water flowing through each path. The dynamic pressure of the water flowing through the first section A1 is distributed to the second path CL2 and the second section A2 at the branch point PS. In the hydrogen generator 1 illustrated in FIG. 1, a temperature control valve TCV is provided in the second path CL2 to adjust the flow resistance of water in the second path CL2 and thereby adjust the flow rate of water in the second path CL2 and also adjust the flow rate in the second section A2. The temperature control valve TCV may be provided on the second section A2 side, or may be provided in both the second path CL2 and the second section A2. A three-way temperature control valve may be used as the temperature control valve TCV, and the junction point PJ and the branch point PS may be configured using the three-way temperature control valve.

[0029] The temperature of the water supplied to the electrolysis device 10 is, for example, 70°C or higher. The temperature of the water supplied to the electrolysis device 10 may be 75°C or higher, or 80°C or higher. The temperature of the water supplied to the electrolysis device 10 is, for example, 95°C or lower. In the first heat exchanger HX1, heat exchange is performed so that the temperature of the water immediately after passing through the first heat exchanger HX1 is, for example, 75°C or higher. The temperature of the water immediately after passing through the first heat exchanger HX1 may be 80°C or higher, 85°C or higher, or 90°C or higher. The temperature of the water immediately after passing through the first heat exchanger HX1 is, for example, 98°C or lower.

[0030] In this embodiment, in order to heat water in the first heat exchanger HX1, a heat medium having a temperature higher than that of the water is supplied to the first heat exchanger HX1. The supplied heat medium may be a gaseous fluid, a liquid fluid, or a gas-liquid mixed fluid. The liquid fluid may be a slurry containing solid particles.

[0031] A common heating device such as a water heater or an oil heater can be used to supply the heated heat medium. Furthermore, waste heat from a facility attached to the hydrogen generator 1 can be used to heat the water in the first heat exchanger HX1. For example, the water can be heated using waste heat from a boiler SB. Specifically, for example, if the first heat exchanger HX1 is a plate-type heat exchanger, the first heat exchanger HX1 can be arranged so that one of two flow paths adjacent to each other via a plate in the plate-type heat exchanger forms part of the first path CL1 (second section A2), and high-temperature cooling water used to cool the boiler SB can be circulated through the other flow path. Furthermore, if the first heat exchanger HX1 is a shell-tube heat exchanger, the first heat exchanger HX1 can be arranged so that the tubes of the heat exchanger form part of the first path CL1 (second section A2), and high-temperature cooling water used to cool the boiler SB and exhaust gas can be circulated through the shell side. If the first heat exchanger HX1 is a finned tube type heat exchanger, the first heat exchanger HX1 is arranged so that the finned tubes form part of the first path CL1 (second section A2), and the finned tubes are arranged in a duct through which the exhaust gas from the boiler SB flows.

[0032] In the second heat exchanger HX2 of this embodiment, water can be cooled using cooling water or the like in a facility attached to the hydrogen generation apparatus 1. The second heat exchanger HX2 is used to cool the water discharged from the electrolysis device 10 without damaging the ion exchange resin used in the ion exchanger 20.

[0033] In the second heat exchanger HX2, a heat transfer medium having a lower temperature than the water to be cooled is supplied to the second heat exchanger HX2 to cool the water. As in the case of the first heat exchanger HX1, the supplied heat transfer medium may be a gaseous fluid, a liquid fluid, or a gas-liquid mixed fluid. The liquid fluid may be a slurry containing solid particles.

[0034] In the second heat exchanger HX2, heat exchange is performed so that the temperature of the water immediately after passing through the second heat exchanger HX2 is, for example, 60°C or less. The temperature of the water immediately after passing through the second heat exchanger HX2 may be 50°C or less, or may be 45°C or less. The temperature of the water immediately after passing through the second heat exchanger HX2 is, for example, 35°C or more.

[0035] When the second heat exchanger HX2 is a plate-type heat exchanger, for example, the second heat exchanger HX2 can be arranged to form part of the third path CL3 in one of two adjacent paths separated by a plate in the plate-type heat exchanger, and cooling water cooled in a cooling tower CT can be circulated through the other path, thereby cooling the water supplied to the ion exchanger 20 to a predetermined temperature. When the second heat exchanger HX2 is a shell-and-tube heat exchanger, for example, the second heat exchanger HX2 can be arranged to form part of the third path CL3 with its tubes, and cooling water cooled in a cooling tower CT can be circulated through the shell side. When the first heat exchanger HX1 is a fin-tube heat exchanger, the second heat exchanger HX2 can be arranged to form part of the third path CL3 with its fin tubes. The fin tubes can be cooled by blowing air onto them with a fan, or the fin tubes can be immersed in water in a water tank.

[0036] The temperature of the cooling water introduced into the second heat exchanger HX2 to exchange heat with the water flowing through the water circulation path CL (third water path CL3) is set to, for example, 45° C. or lower. The temperature of the cooling water may be 40° C. or lower, 35° C. or lower, or 30° C. or lower. The temperature of the cooling water is set to, for example, 15° C. or higher.

[0037] In the hydrogen generation device 1 of this embodiment, the water temperature adjustment device TC effectively functions to supply high-temperature water to the electrolysis device 10 to improve electrolysis efficiency. The operating status of the electrolysis device 10 may fluctuate depending on the demand for hydrogen gas. Furthermore, the amount of heat exchanged in the heat exchanger varies due to various factors, as described above. Therefore, if water that has passed through the first heat exchanger HX1 is directly supplied to the electrolysis device 10, the water heated in the electrolysis device 10 may exceed its boiling point. Therefore, if the temperature of the water supplied to the electrolysis device 10 is adjusted using only the first heat exchanger HX1, it is necessary to lower the set temperature of the water supplied to the electrolysis device 10 in anticipation of temperature variations. On the other hand, in this embodiment, temperature adjustment is performed not only by the first heat exchanger HX1 but also by the temperature control valve TCV. Therefore, the temperature of the water supplied to the electrolysis device 10 can be set higher within the electrolysis device 10 within a range that does not exceed the boiling point, thereby maintaining high electrolysis efficiency.

[0038] The temperature control valve TCV in this embodiment does not need to be used to keep the temperature of the water supplied to the electrolysis device 10 constant regardless of the operating state, and may be used, for example, to change the temperature of the water supplied to the electrolysis device 10 depending on the operating state of the electrolysis device 10 (the heating state of water in the electrolysis device 10).

[0039] (Second embodiment) Next, a second embodiment of the present invention will be described below. The hydrogen generation device 1 of the second embodiment shown in Fig. 3 is the same as the hydrogen generation device 1 of the first embodiment in that it has a water temperature adjustment device TC and thereby performs the functions described above.

[0040] In the first embodiment, the heat source (hot heat source) for heating water in the first heat exchanger HX1 and the heat source (cold heat source) for cooling water in the second heat exchanger HX2 were separate, whereas in the second embodiment, heat is transferred from the second heat exchanger HX2 to the first heat exchanger HX1. More specifically, in the first embodiment, the heat sources of the first heat exchanger HX1 and the second heat exchanger HX2 were separate, and the temperature adjustments in each heat exchanger were performed independently of each other, but the hydrogen generation apparatus 1 of the second embodiment is configured so that the heat obtained in the second heat exchanger HX2 is transferred to the first heat exchanger HX1 and used as a hot heat source in the first heat exchanger HX1.

[0041] The hydrogen generation device 1 in the second embodiment differs from the hydrogen generation device 1 in the first embodiment in that the water temperature adjustment device TC has a heat transfer means that transfers heat from the water flowing between the electrolysis device 10 and the ion exchanger 20 to the water flowing between the ion exchanger 20 and the confluence PJ, thereby supplying the ion exchanger 20 with water that is at a lower temperature than the water discharged from the electrolysis device 10.

[0042] In the hydrogen generator 1 of the second embodiment, the heat medium passes through the second heat exchanger HX2 to cool the water flowing through the water circulation path CL, and the heat medium, whose temperature has increased, is used to heat the water in the first heat exchanger HX1, and heat is transferred from the second heat exchanger HX2 to the first heat exchanger HX1. In the hydrogen generator 1 of the second embodiment, the heat medium supplied to the first heat exchanger HX1 after passing through the second heat exchanger HX2 preferably has a large heat capacity per unit volume and is preferably in a liquid state (liquid or slurry).

[0043] In the hydrogen generation device 1 of the second embodiment, the water temperature adjustment device TC has a second heat exchanger HX2 that exchanges heat with water flowing between the electrolysis device 10 and the ion exchanger 20, and has the heat transfer means that transfers heat from the second heat exchanger HX2 to the first heat exchanger HX1 and transfers heat to the water flowing in the second section A2. In this embodiment, water that is discharged from the electrolysis device 10 without being electrolyzed is used as a heat source for heating water in the first heat exchanger HX1.

[0044] The second heat exchanger HX2 in this embodiment may be provided upstream of the anode-side gas-liquid separator 30 (between the electrolysis device 10 and the anode-side gas-liquid separator 30) because it is capable of heat exchange with water at a higher temperature. However, because heat exchange is easier with water after gas-liquid separation than with water in a gas-liquid mixed state before gas-liquid separation, the second heat exchanger HX2 in this embodiment is provided downstream of the anode-side gas-liquid separator 30 (between the anode-side gas-liquid separator 30 and the ion exchanger 20). When the second heat exchanger HX2 is a finned tube heat exchanger, for example, as shown in FIG. 4 , finned tubes may be disposed in the anode-side gas-liquid separator 30, and a heat medium (refrigerant) for cooling the water in the anode-side gas-liquid separator 30 may be circulated through the finned tubes so that the entire water contained in the anode-side gas-liquid separator 30 serves as a heat source for heating the water in the first heat exchanger HX1.

[0045] In the hydrogen generation device 1 of this embodiment, the heat medium heated in the second heat exchanger HX2 is transferred to the first heat exchanger HX1 and used as a heat source in the first heat exchanger HX1, thereby reducing the need to introduce a heat source for heating from outside the device, thereby achieving energy savings and simplifying the control method and device configuration.

[0046] (Third embodiment) The hydrogen generator 1 of the third embodiment shown in Fig. 5 is common to the hydrogen generator 1 of the second embodiment in that it has a heat transfer means. While the second embodiment is provided with heat transfer means that transfer heat using two heat exchangers, a first heat exchanger HX1 and a second heat exchanger HX2, the hydrogen generator 1 of the third embodiment differs from the second embodiment in that heat is transferred using a single heat exchanger that exchanges heat between water before and after passing through the ion exchanger 20.

[0047] In the hydrogen generation apparatus 1 of the third embodiment, the water temperature adjustment device TC has a second heat exchanger HX2 that exchanges heat with water flowing between the electrolysis device 10 and the ion exchanger 20, and has the heat transfer means that passes the water flowing in the first section A1 through the second heat exchanger HX2 to transfer heat from the water flowing upstream of the ion exchanger 20 to the water flowing in the first section A1. That is, the hydrogen generation apparatus 1 of the third embodiment is configured so that the water flowing in the water circulation path CL functions as a hot medium (arrow H pointing toward the second heat exchanger HX2) or a cold medium (arrow C pointing toward the second heat exchanger HX2) that is supplied to the second heat exchanger HX2.

[0048] The hydrogen generation device 1 of this embodiment is similar to the first and second embodiments in that it is configured to circulate water through the electrolysis device 10. The temperature of the water flowing through the water circulation path CL increases due to Joule heat generated in the electrolysis device 10 and heat generated in the pump CP. The temperature of the water supplied from the water supply equipment 40 is usually lower than the temperature of the water flowing through the water circulation path CL (water discharged from the electrolysis device 10). Therefore, it is considered that the temperature of the water flowing through the water circulation path CL decreases to some extent due to the water supply from the water supply equipment 40. Normally, heating by the electrolysis device 10 and the pump CP dominates over the temperature decrease due to the water supply. In this embodiment, the heat balance in the second heat exchanger HX2 is basically zero, so while the first heat exchanger HX1 is used to heat water in the first and second embodiments, in this embodiment the first heat exchanger HX1 is used to cool water.

[0049] The hydrogen generator 1 of this embodiment is similar to the first and second embodiments in that a temperature difference is created between the water flowing through the second path CL2 and the water flowing through the second section A2 by the first heat exchanger HX1, but differs from the first and second embodiments in that, while in the first and second embodiments the water flowing through the second section A2 is heated by the first heat exchanger HX1 to make it hotter than the water flowing through the second path CL2, in this embodiment the water flowing through the second section A2 is cooled by the first heat exchanger HX1 to make it colder than the water flowing through the second path CL2. Note that, in this case as well, temperature adjustment is performed by the temperature control valve TCV in addition to the first heat exchanger HX1, so that the temperature of the water supplied to the electrolysis device 10 can be adjusted more accurately, similar to the first and second embodiments.

[0050] In the hydrogen generation device 1 of this embodiment, for example, as shown in FIG. 6, in order to prevent the second heat exchanger HX2 from insufficiently cooling the water and supplying high-temperature water to the ion exchanger 20, the water temperature adjustment device TC may be provided with a third heat exchanger HX3 that cools the water between the second heat exchanger HX2 and the ion exchanger 20.

[0051] As described above, the hydrogen generators 1 according to the first, second, and third embodiments perform a hydrogen gas production method in which water is circulated through the electrolysis device 10 and the ion exchanger 20, water is electrolyzed in the electrolysis device 10, and ions contained in the water before electrolysis are removed in advance in the ion exchanger 20 to generate hydrogen gas. The hydrogen generators 1 according to the first, second, and third embodiments split the water flow into multiple streams, including a first stream and a second stream, between the ion exchanger 20 and the electrolysis device 10, and then merge the multiple streams to supply them to the electrolysis device 10. A temperature difference is provided between the first stream and the second stream, and the flow rate ratio of the first stream to the second stream is adjusted by the temperature control valve TCV to adjust the water temperature after merging. Therefore, the hydrogen generators 1 according to the first, second, and third embodiments can stably adjust the temperature of the water supplied to the electrolysis device 10 over time with little error from a target value, even when the first stream or the second stream is heated or cooled by a heat exchanger, which is difficult to precisely adjust the temperature of.

[0052] The present invention is not limited to the first, second, and third embodiments described above, and various modifications can be made thereto. In other words, the present invention is not limited to the above examples.

[0053] As mentioned above, this specification includes the following disclosures. (1) an electrolysis device that electrolyzes water to generate hydrogen; a water circulation path for circulating water through the electrolysis device; an ion exchanger for removing ions contained in the water flowing through the water circulation path; a water temperature adjusting device that adjusts the temperature of the water flowing through the water circulation path, The water temperature adjustment device is the system is configured to supply to the ion exchanger water having a lower temperature than the water discharged from the electrolysis device, and to supply to the electrolysis device water having a higher temperature than the water supplied to the ion exchanger, and includes one or more heat exchangers including a first heat exchanger that exchanges heat with the water that has passed through the ion exchanger upstream of the electrolysis device; The water circulation path is a first path from the ion exchanger through the first heat exchanger to the electrolyzer; a second path branching from the first path between the ion exchanger and the first heat exchanger and joining the first path between the first heat exchanger and the electrolysis device; a third path from the electrolysis device to the ion exchanger; The first pathway is the route has three sections separated by a branch point with the second route and a junction point with the second route, the three sections being composed of a first section upstream of the branch point, a second section after the branch point and upstream of the junction point, and a third section after the junction point; The water temperature adjustment device is a temperature control valve that adjusts the ratio between the amount of water flowing through the second section and the amount of water flowing through the second path to adjust the temperature of the water supplied to the electrolysis device.

[0054] (2) The hydrogen generating apparatus according to (1), wherein the temperature control valve is configured to adjust the ratio based on at least one of the following (a), (b), and (c): (a) the temperature of the water that joins at the joining point and is supplied to the electrolysis device; (b) the temperature of each of the waters that meet at said junction (c) the temperature of the water discharged from the electrolysis device

[0055] (3) The water temperature adjustment device is The hydrogen generation device according to (1) or (2), further comprising a heat transfer means for transferring heat from the water flowing between the electrolysis device and the ion exchanger to the water flowing between the ion exchanger and the junction, thereby supplying the ion exchanger with water having a lower temperature than the water discharged from the electrolysis device.

[0056] (4) The water temperature adjustment device is a second heat exchanger that exchanges heat with water flowing between the electrolysis device and the ion exchanger; The hydrogen generating apparatus according to (3), further comprising a heat transfer means for transferring heat from the second heat exchanger to the first heat exchanger and transferring the heat to the water flowing through the second section.

[0057] (5) The water temperature adjustment device is a second heat exchanger that exchanges heat with water flowing between the electrolysis device and the ion exchanger; The hydrogen generating apparatus according to (3), further comprising the heat transfer means for transferring heat to the water flowing through the first section by passing the water flowing through the second heat exchanger. [Explanation of symbols]

[0058] 1: Hydrogen generator, 10: Electrolyzer, 11: Electrolyzer body, 12: Power supply, 20: Ion exchanger, 30: Anode side gas-liquid separator, 40: Water supply equipment, CL: Water circulation pathway, CL1: 1st pathway, CL2: 2nd pathway, CL3: 3rd pathway, CP: Pump, CT: cooling tower, HX1: first heat exchanger, HX2: second heat exchanger, HX3: third heat exchanger, PJ: confluence, PS: branch point, SB: Boiler, TC: Water temperature control device, TCV: Temperature Control Valve.

Claims

1. an electrolysis device that electrolyzes water to generate hydrogen; a water circulation path for circulating water through the electrolysis device; an ion exchanger for removing ions contained in the water flowing through the water circulation path; a water temperature adjusting device that adjusts the temperature of the water flowing through the water circulation path, The water temperature adjustment device is the system is configured to supply to the ion exchanger water having a lower temperature than the water discharged from the electrolysis device, and to supply to the electrolysis device water having a higher temperature than the water supplied to the ion exchanger, and includes one or more heat exchangers including a first heat exchanger that exchanges heat with the water that has passed through the ion exchanger upstream of the electrolysis device; The water circulation path is a first path from the ion exchanger through the first heat exchanger to the electrolyzer; a second path branching from the first path between the ion exchanger and the first heat exchanger and joining the first path between the first heat exchanger and the electrolysis device; a third path from the electrolysis device to the ion exchanger; The first pathway is the route has three sections separated by a branch point with the second route and a junction point with the second route, the three sections being composed of a first section upstream of the branch point, a second section after the branch point and upstream of the junction point, and a third section after the junction point; The water temperature adjustment device is a temperature control valve that adjusts the ratio between the amount of water flowing through the second section and the amount of water flowing through the second path to adjust the temperature of the water supplied to the electrolysis device so that it is within a predetermined temperature range.

2. 2. The hydrogen generating apparatus of claim 1, wherein the temperature regulating valve is configured to regulate the ratio based on at least one of the following: (a) a temperature of the hydrogen generator; (b) a temperature of the hydrogen generator; and (c) a temperature of the hydrogen generator. (a) the temperature of the water that joins at the joining point and is supplied to the electrolysis device (b) the temperature of each of the waters that are joined at the joining point (c) the temperature of the water discharged from the electrolysis device

3. The water temperature adjustment device is 3. The hydrogen generation apparatus according to claim 1, further comprising a heat transfer means for transferring heat from the water flowing between the electrolysis device and the ion exchanger to the water flowing between the ion exchanger and the junction, thereby supplying the ion exchanger with water having a lower temperature than the water discharged from the electrolysis device.

4. The water temperature adjustment device is a second heat exchanger that exchanges heat with water flowing between the electrolysis device and the ion exchanger; 4. The hydrogen generating apparatus according to claim 3, further comprising heat transfer means for transferring heat from said second heat exchanger to said first heat exchanger and transferring heat to water flowing through said second section.

5. The water temperature adjustment device is a second heat exchanger that exchanges heat with water flowing between the electrolysis device and the ion exchanger; 4. The hydrogen generating apparatus according to claim 3, further comprising said heat transfer means for transferring heat to the water flowing through said first section by passing said water flowing through said first section through said second heat exchanger.

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