Operation method for dehumidifier device, control device for dehumidifier device, dehumidifier device, and hydrogen production facility

Abstract

Provided is an operation method for a dehumidifier device for dehumidifying hydrogen gas produced by a hydrogen production device. The dehumidifier device comprises; a dehumidifier; a discharge line for discharging hydrogen gas dehumidified by the dehumidifier from the dehumidifier; a dew point measurement line connected to the discharge line; a dew point meter provided on the dew point measurement line; and an inlet valve and an outlet valve provided on opposite sides of the dew point meter on the dew point measurement line. The method includes: a stop step of stopping discharge of the hydrogen gas from the dehumidifier to the discharge line; and a maintenance step of maintaining a state in which a dew point meter installation part including at least a installation place of the dew point meter on the dew point measurement line is filled with dry gas when the discharge of the hydrogen gas from the dehumidifier to the discharge line is stopped.

Description

Dehumidifier operating method, dehumidifier control device, dehumidifier and hydrogen production facility

[0001] This disclosure relates to a method for operating a dehumidifier, a control device for a dehumidifier, a dehumidifier, and hydrogen production equipment. This application claims priority based on Japanese Patent Application No. 2024-003251, filed with the Japan Patent Office on January 12, 2024, the contents of which are incorporated herein by reference.

[0002] In hydrogen production facilities, dehumidifiers are used to remove moisture from hydrogen gas produced in hydrogen production equipment such as water decomposition units. To check the performance of the dehumidifier, a dew point meter installed on the outlet side of the dehumidifier is sometimes used to measure the dew point (dew point temperature) of the hydrogen gas dehumidified by the dehumidifier.

[0003] Patent Document 1 describes a water electrolysis system (hydrogen production facility) including a water electrolysis device, a dehumidification device for dehumidifying hydrogen discharged from the water electrolysis device, and a dew point meter for measuring the dew point of the hydrogen dehumidified by the dehumidifier.

[0004] JP 2014-40637 A

[0005] Dew point meters have dew point conditions (usage conditions) for dehumidified hydrogen. When dehumidified hydrogen is not circulating at the location where the dew point meter is installed, such as when the dehumidifier is stopped, the dew point at the location where the dew point meter is installed may rise due to the intrusion of air, causing the dew point at the location to fall outside the range of the hydrogen usage conditions. For this reason, when the dehumidifier is restarted, hydrogen gas dehumidified by the dehumidifier is typically supplied to the location where the dew point meter is installed until the dew point at the location where the dew point meter is installed falls within the range of the hydrogen usage conditions. However, it takes a long time for the hydrogen at the location where the dew point meter is installed to fall within the dew point range of the usage conditions and become capable of appropriate dew point measurement.

[0006] Furthermore, hydrogen production facilities may produce hydrogen in response to fluctuations in power supply, such as renewable energy sources, or in response to fluctuations in demand on the demand side. In such cases, the frequency of switching on and off the entire hydrogen production facility, including the dehumidifier, increases. As a result, each time the hydrogen production facility is restarted, it takes a long time, as mentioned above, for the hydrogen dew point at the dew point meter to fall within the range of operating conditions, and this increased standby time can become a problem.

[0007] In view of the above circumstances, at least one embodiment of the present invention aims to provide a method for operating a dehumidifier, a control device for a dehumidifier, a dehumidifier, and hydrogen production equipment that can quickly start appropriate dew point measurement when the dehumidifier is restarted.

[0008] a dew point meter provided in the dew point measurement line; an inlet valve provided in the dew point measurement line at a position closer to the connection point with the discharge line than the dew point meter; and an outlet valve provided in the dew point measurement line at a position opposite the inlet valve, with the dew point meter sandwiched between the dew point meter and the dew point measurement line; and a stopping step of stopping the discharge of the hydrogen gas from the dehumidifier to the discharge line; and a maintaining step of maintaining a state in which at least a dew point meter installation portion of the dew point measurement line, including an installation position of the dew point meter, is filled with dry gas when the discharge of the hydrogen gas from the dehumidifier to the discharge line is stopped.

[0009] Furthermore, at least one embodiment of the present invention provides a control device for a dehumidifier, which is a control device for controlling the operation of a dehumidifier for dehumidifying hydrogen gas produced in a hydrogen production apparatus, the dehumidifier including: a dehumidifier for dehumidifying moisture contained in hydrogen gas; a discharge line for discharging the hydrogen gas dehumidified by the dehumidifier from the dehumidifier; a dew point measurement line connected to the discharge line; a dew point meter provided in the dew point measurement line; an inlet valve provided in the dew point measurement line at a position closer to the connection point with the discharge line than the dew point meter; and an outlet valve provided in the dew point measurement line at a position opposite the inlet valve, with the dew point meter in between; and the control device is configured to operate the opening and closing of the inlet valve or the outlet valve so that, when discharge of the hydrogen gas from the dehumidifier to the discharge line is stopped, a state in which at least the dew point meter installation portion of the dew point measurement line, which includes the installation location of the dew point meter, is maintained filled with dry gas.

[0010] Furthermore, at least one embodiment of the present invention provides a dehumidification device for dehumidifying hydrogen gas produced in a hydrogen production apparatus, the dehumidification device comprising: a dehumidifier for dehumidifying moisture contained in hydrogen gas; an exhaust line for discharging the hydrogen gas dehumidified by the dehumidifier from the dehumidifier; a dew point measurement line connected to the exhaust line; a dew point meter provided on the dew point measurement line; an inlet valve provided on the dew point measurement line at a position closer to the connection point with the exhaust line than the dew point meter; and an outlet valve provided on the dew point measurement line at a position opposite the inlet valve across the dew point meter, and configured so that the hydrogen gas that has passed through the outlet valve on the dew point measurement line is released into the atmosphere.

[0011] Moreover, a hydrogen production facility according to at least one embodiment of the present invention includes: a hydrogen production device; and the above-described dehumidification device configured to dehumidify the hydrogen gas produced by the hydrogen production device.

[0012] According to at least one embodiment of the present invention, there are provided a method for operating a dehumidifier, a control device for a dehumidifier, a dehumidifier, and hydrogen production equipment that enable appropriate dew point measurement to be started promptly when the dehumidifier is restarted.

[0013] Fig. 1 is a schematic diagram showing a hydrogen production facility according to an embodiment; Fig. 2 is a schematic diagram showing a hydrogen production facility according to an embodiment; Fig. 3 is a time chart showing an example of the open / closed state of a valve in a dehumidifier when an operating method according to an embodiment is applied; Fig. 4 is a time chart showing an example of the open / closed state of a valve in a dehumidifier when an operating method according to an embodiment is applied; Fig. 5 is a time chart showing an example of the open / closed state of a valve in a dehumidifier when an operating method according to an embodiment is applied.

[0014] Hereinafter, several embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present invention.

[0015] 1 and 2 are schematic diagrams showing an example of a hydrogen production facility including a dehumidifier to which an operating method according to an embodiment is applied. As shown in FIGS. 1 and 2, the hydrogen production facility 1 includes a hydrogen production device 10 for producing hydrogen and a dehumidifier 20 for dehumidifying the hydrogen gas produced by the hydrogen production device 10.

[0016] The hydrogen production device 10 shown in FIGS. 1 and 2 includes a water electrolysis device 12 configured to electrolyze water to produce hydrogen and oxygen, and a gas-liquid separator 14 configured to guide the hydrogen gas produced in the water electrolysis device 12.

[0017] The water electrolysis device 12 may be, for example, an alkaline water electrolysis device, a polymer electrolyte membrane (PEM) water electrolysis device, an anion exchange membrane (AEM) water electrolysis device, or a solid oxide electrolysis cell (SOEC) water electrolysis device.

[0018] The water electrolysis device 12 includes an electrolytic cell for electrolyzing water. Water is supplied to the electrolytic cell. A current is supplied to the electrolytic cell via a rectifier. This applies a voltage between electrodes provided in the electrolytic cell to pass a current, thereby electrolyzing the water in the electrolytic cell, generating hydrogen on the cathode side and oxygen on the anode side. Water in which an electrolyte is dissolved (electrolyte solution) may be supplied to the electrolytic cell, and the water (water constituting the electrolyte solution) may be electrolyzed. The electrolyte may be an alkaline substance such as potassium hydroxide (KOH).

[0019] The hydrogen gas generated in the electrolytic cell of the water electrolysis device 12 is discharged from the electrolytic cell together with moisture and is guided to the gas-liquid separator 14 via a hydrogen line 16. In the gas-liquid separator 14, the moisture-containing hydrogen gas is separated into hydrogen gas and water (liquid). The gas-phase hydrogen gas in the gas-liquid separator 14 contains moisture equivalent to saturated vapor. This hydrogen gas is discharged from the gas-liquid separator 14 and guided to a dehumidifier 20. The water (electrolyte solution) separated in the gas-liquid separator 14 is returned to the electrolytic cell of the water electrolysis device 12 via a return line (not shown).

[0020] The oxygen generated in the water electrolysis device 12 may be discharged from the electrolytic cell via an oxygen line (not shown) and then used in an oxygen-using device or released to the outside.

[0021] The dehumidification device 20 includes a dehumidifier 22, an inlet line 24 for introducing hydrogen gas into the dehumidifier 22, and an outlet line 28 for discharging the hydrogen gas from the dehumidifier 22. The inlet line 24 and the outlet line 28 may be provided with an inlet valve 25 and an outlet valve 29, respectively.

[0022] The dehumidifier 22 may include at least one adsorption tower provided with an adsorbent capable of adsorbing moisture. The inlet line 24 is provided between the hydrogen production device 10 and the dehumidifier 22, and is configured to guide hydrogen gas (wet hydrogen gas) from the hydrogen production device 10 to the dehumidifier 22. The outlet line 28 is configured to discharge hydrogen gas dehumidified by the dehumidifier 22 (dry hydrogen gas) from the dehumidifier 22. In other words, the hydrogen gas introduced into the dehumidifier 22 via the inlet line 24 is dehumidified by the adsorbent and then discharged from the dehumidifier 22.

[0023] The inlet valve 25 may be configured to adjust the amount of hydrogen gas (wet hydrogen gas) that flows from the gas-liquid separator 14 to the dehumidifier 22. The outlet valve 29 may be configured to adjust the amount of hydrogen gas (dry hydrogen gas) that is discharged from the dehumidifier 22.

[0024] The dehumidifier 20 may include a vent line 26 connected to the adsorption tower (dehumidifier 22) for releasing hydrogen gas from the adsorption tower (dehumidifier 22) to the outside, and a vent valve 27 provided in the vent line 26. The vent line 26 functions as a line for discharging regeneration gas supplied for regenerating the adsorbent from the adsorption tower when performing a regeneration process for the adsorbent provided inside the adsorption tower. During normal operation (dehumidification) of the hydrogen production facility 1 and the dehumidifier 20, the vent valve 27 is basically closed.

[0025] The hydrogen gas (dehumidified hydrogen gas) discharged from the dehumidifier 22 via the discharge line 28 may be stored in a storage unit (tank) or the like, or may be supplied to a hydrogen-consuming facility (user). The hydrogen-consuming facility may include, for example, a hydrogen combustion facility configured to combust hydrogen (e.g., a gas turbine facility or a steelmaking facility), a hydrogen liquefaction facility configured to liquefy hydrogen, a facility that generates electricity through a chemical reaction using hydrogen as fuel (e.g., a power generation facility including a fuel cell such as an SOFC (Solid Oxide Fuel Cell)), a facility that produces fuel using hydrogen as a raw material (e.g., a fuel synthesis facility), or a hydrogen gas station configured to supply hydrogen to equipment.

[0026] 1 and 2 , the dehumidifier 20 further includes a dew point measurement line 32 connected to the discharge line 28, a dew point meter 34 provided on the dew point measurement line 32, and an inlet valve 36 and an outlet valve 38 provided on the dew point measurement line 32. The upstream end of the dew point measurement line 32 is connected to the discharge line 28. The inlet valve 36 is provided on the dew point measurement line 32 closer to the connection point 30 with the discharge line 28 than the dew point meter 34 (i.e., upstream of the dew point meter 34). The outlet valve 38 is provided on the dew point measurement line 32 on the opposite side of the dew point meter 34 from the inlet valve 36 (i.e., downstream of the dew point meter 34).

[0027] The dew point meter 34 is configured to measure the dew point of the gas in the dew point measurement line 32. During operation of the hydrogen production device 10 (i.e., during hydrogen production), the hydrogen gas discharged from the dehumidifier 22 flows through the discharge line 28, and a portion of this gas is guided to the dew point measurement line 32 and becomes the target for dew point measurement by the dew point meter 34. Therefore, the dew point measured by the dew point meter 34 during operation of the hydrogen production device 10 indicates the dew point of the hydrogen gas flowing through the discharge line 28 (hydrogen gas supplied to hydrogen consumption equipment, etc.).

[0028] There is no particular limitation on the type of dew-point meter 34. For example, a capacitance type dew-point meter, a cooled mirror type dew-point meter, or a quartz oscillator type dew-point meter can be used as the dew-point meter 34.

[0029] The hydrogen gas introduced into the dew point measurement line 32 passes through the outlet valve 38 and is then released into the atmosphere via the dew point measurement line 32. For example, the downstream end of the dew point measurement line 32 may be open to the atmosphere, or a device (pipe, etc.) to which the downstream end of the dew point measurement line 32 is connected may be open to the atmosphere.

[0030] 2 , the dehumidification device 20 includes a dry gas supply unit 40 for supplying dry gas to the dew point measurement line 32. The dry gas supply unit 40 includes a dry gas storage unit 42 (such as a gas tank or gas cylinder) for storing dry gas, a supply line 44 provided between the dry gas storage unit 42 and the dew point measurement line 32, and a supply valve 46 provided on the supply line 44.

[0031] The supply line 44 is configured to supply dry gas to a portion of the dew point measurement line 32 between the inlet valve 36 and the outlet valve 38. As shown in FIG. 2 , the supply line 44 may be connected to a portion of the dew point measurement line 32 between the inlet valve 36 and the dew point meter 34.

[0032] The dry gas may be a gas having a dew point equal to or lower than the upper limit of the measurable range of the dew point meter 34. The dry gas may be a gas having a dew point equal to or higher than the lower limit and equal to or lower than the upper limit of the measurable range of the dew point meter 34.

[0033] The dry gas may be, for example, a gas having a dew point at atmospheric pressure of 0° C. or less. The dry gas may be, for example, a gas having a dew point at atmospheric pressure of −100° C. or more and 0° C. or less.

[0034] The dry gas may comprise hydrogen or an inert gas such as nitrogen or argon. The dry gas may be hydrogen with a purity of 99.0% or greater or an inert gas such as nitrogen or argon.

[0035] 1 and 2, the dehumidifier 20 may further include a control device 50 for controlling the opening and closing of the inlet valve 36 and the outlet valve 38 provided in the dew point measurement line 32. The control device 50 may be configured to control the opening and closing of the discharge valve 29 in the discharge line 28 through which hydrogen discharged from the dehumidifier 22 flows. The control device 50 may also be configured to adjust the aperture of the supply valve 46 (see FIG. 2) provided in the supply line 44. The inlet valve 36, the outlet valve 38, the discharge valve 29, and / or the supply valve 46 may each be electrically connected to the control device, and an electrical signal indicating an opening / closing command or an aperture command from the control device may be given to each valve.

[0036] 2, an electrical signal indicating the dew point (measured value) measured by the dew point meter 34 may be sent to a control device 50. The control device 50 may be configured to control the opening and closing of the inlet valve 36, the outlet valve 38, and / or the supply valve 46 based on the measured value by the dew point meter 34.

[0037] The control device 50 includes a computer equipped with a processor (such as a CPU), a main storage device (such as a memory device; such as a RAM), an auxiliary storage device, an interface, and the like. The control device 50 may be configured to receive a signal from the dew point meter 34 via the interface. The processor is configured to process the signal thus received. The processor is also configured to process a program loaded in the main storage device.

[0038] The processing contents of the control device 50 are implemented as programs executed by the processor. The programs may be stored in, for example, an auxiliary storage device. When the programs are executed, they are loaded into the main storage device. The processor reads the programs from the main storage device and executes the instructions contained in the programs.

[0039] (Operating Method of Dehumidifier) ​​Next, an operating method of the dehumidifier 20 according to several embodiments will be described. Figures 3 to 5 are time charts each showing an example of the open / closed state of the valve in the dehumidifier 20 when an operating method according to one embodiment is applied. t10 to t36 in Figures 3 to 5 each indicate a time.

[0040] In the operation method of the dehumidifier described below, the opening / closing or adjustment of the opening degree of the inlet valve 36, outlet valve 38, supply valve 46 and / or discharge valve 29 may be performed using the above-mentioned control device 50 or may be performed manually.

[0041] A method for operating a dehumidifier 20 according to some embodiments is applied when stopping an operating dehumidifier 20. During normal operation of the dehumidifier 20 (t12 to t13 in FIG. 3 , t22 to t23 in FIG. 4 , and t32 to t33 in FIG. 5 ), hydrogen gas generated in the hydrogen production device 10 is introduced into the dehumidifier 20 via the gas-liquid separator 14 and dehumidified, and the dehumidified hydrogen gas is discharged from the dehumidifier 20 via the discharge line 28. At this time, a discharge valve 29 provided on the discharge line 28 is open. During normal operation of the dehumidifier 20, the inlet valve 36 and the outlet valve 38 of the dew point measurement line 32 are open, and a portion of the hydrogen gas flowing through the discharge line 28 is introduced into the dew point measurement line 32, and the dew point of the hydrogen gas is measured by the dew point meter 34. The hydrogen gas flowing through the dew point measurement line 32 and passing through the dew point meter 34 and the outlet valve 38 is released into the atmosphere.

[0042] In some embodiments, when the operation of the dehumidifier 22 is stopped, such as when the hydrogen production device 10 is shut down, the discharge of hydrogen gas (dehumidified hydrogen gas) from the dehumidifier 22 to the discharge line 28 is stopped (stopping step; t15 in FIG. 3 , t23 in FIG. 4 , and t33 in FIG. 5 ). In the stopping step, the discharge valve 29 provided in the discharge line 28 is closed, thereby stopping the discharge of hydrogen gas from the dehumidifier 22 to the discharge line 28.

[0043] When the discharge of hydrogen gas from the dehumidifier 22 to the discharge line 28 is stopped, the dew point meter installation portion of the dew point measurement line 32, which includes at least the installation location of the dew point meter 34, is maintained in a state filled with dry gas (maintenance step). The dry gas may be hydrogen gas introduced from the dehumidifier 22 (dehumidified hydrogen gas), or may be dry gas supplied from the dry gas supply unit 40 (see FIG. 2).

[0044] Here, the dew point meter 34 has dew point conditions (usage conditions) for dehumidified hydrogen. When dehumidified hydrogen gas is not flowing through the installation location of the dew point meter 34, such as when the dehumidifier 22 is stopped, the dew point at the installation location of the dew point meter 34 may rise due to the intrusion of atmospheric air, etc., and fall outside the range of the usage conditions for hydrogen. For example, in a dehumidification device 20 configured to release hydrogen gas into the atmosphere through a dew point measurement line 32 connected to the exhaust line 28, when the dehumidifier 22 is stopped, if the discharge of hydrogen gas from the dehumidifier 22 to the exhaust line 28 is stopped and hydrogen gas from the dehumidifier 22 no longer flows through the dew point measurement line 32, atmospheric air (humid air) may intrude into the dew point measurement line 32, causing the dew point at the installation location of the dew point meter to rise. Alternatively, when the dehumidifier 22 is stopped, the dew point in the dew point measurement line 32 may rise due to moisture adhering to or contained in the piping that constitutes the dew point measurement line 32.

[0045] In this regard, according to the above-described method, the dew point meter installation portion in the dew point measurement line 32 is kept filled with dry gas when the dehumidifier 22 is stopped, so the dew point at the dew point meter installation portion can be kept low even during periods when the dehumidifier 22 is stopped and dehumidified hydrogen gas is not being discharged from the dehumidifier 22. Therefore, when the dehumidifier 22 is restarted, the dew point at the dew point meter installation portion can be quickly brought within the range of the operating conditions, and therefore appropriate dew point measurement by the dew point meter 34 can be quickly started.

[0046] Furthermore, in some embodiments, when the operation of the dehumidifier 22 is resumed (when it is restarted; t10 in FIG. 3 , t20 in FIG. 4 , and t30 in FIG. 5 ), the maintenance step described above is performed, and the operation of the dehumidifier 22 is resumed with the dew point meter installation section of the dew point measurement line 32 filled with dry gas. That is, when the operation of the dehumidifier 22 is resumed (when it is restarted), the discharge of hydrogen gas (dehumidified hydrogen gas) from the dehumidifier 22 to the discharge line is resumed with the dew point meter installation section of the dew point measurement line 32 filled with dry gas. In the embodiment described below, when the operation of the dehumidifier 22 is resumed (restarted), the discharge valve 29 provided in the discharge line 28 is opened (t10 in FIG. 3 , t20 in FIG. 4 , t30 in FIG. 5 ), and then the inlet valve 36 and / or the outlet valve 38 are opened (t11 and t12 in FIG. 3 , t21 and t22 in FIG. 4 , t32 in FIG. 5 ), but the order of opening and closing the valves is not limited to this. For example, the inlet valve 36 and / or the outlet valve 38 may be opened simultaneously with the opening of the discharge valve 29.

[0047] According to the above-described method, after the dehumidifier 22 is stopped, the discharge of hydrogen gas from the dehumidifier 22 to the discharge line 28 is resumed (i.e., the dehumidifier 22 is restarted) while the dew point meter installation portion of the dew point measurement line 32 is filled with dry gas. In other words, the discharge of hydrogen gas from the dehumidifier 22 to the discharge line 28 is resumed while the dew point at the dew point meter installation portion is maintained low. Therefore, by opening the inlet valve 36 and the outlet valve 38 in this state, hydrogen gas from the dehumidifier 22 can be introduced into the dew point measurement line 32 without causing a substantial increase in the dew point at the dew point meter installation portion. Therefore, when the dehumidifier 22 is restarted, appropriate dew point measurement by the dew point meter 34 can be started promptly.

[0048] Hereinafter, the operation method of the dehumidifier 20 according to some embodiments will be described in more detail with reference to FIGS.

[0049] In some embodiments, in the above-mentioned maintenance step, dry gas may be sealed in the portion 32a of the dew point measurement line 32 between the inlet valve 36 and the outlet valve 38, thereby maintaining the dew point meter installation portion of the dew point measurement line 32 filled with dry gas.

[0050] For example, in the case of the dehumidification device 20 shown in FIG. 1, in the above-mentioned maintenance step, hydrogen gas from the dehumidifier 22 can be sealed as dry gas in the portion 32a of the dew point measurement line 32 between the inlet valve 36 and the outlet valve 38.

[0051] In this case, the operating procedure when the dehumidifier 20 is stopped is, for example, as follows. First, when the discharge of hydrogen gas (dry hydrogen gas) from the dehumidifier 22 to the discharge line 28 is stopped, the inlet valve 36 and the outlet valve 38 provided on the dew point measurement line 32 are closed, thereby sealing the hydrogen gas present in the portion 32a between the inlet valve 36 and the outlet valve 38 in this portion 32a. Then, while the dehumidifier 22 is stopped, the inlet valve 36 and the outlet valve 38 are maintained in a closed state. Here, "when the discharge of hydrogen gas from the dehumidifier 22 to the discharge line 28 is stopped" refers to a time range including the time before and after the time (t15 in FIG. 3 , t23 in FIG. 4 , and t33 in FIG. 5 ) when the discharge valve 29 provided on the discharge line 28 is closed.

[0052] More specifically, for example, the following procedure may be adopted. As shown in FIG. 3 , first, while hydrogen gas (dehumidified hydrogen gas) is discharged from the dehumidifier 22 to the exhaust line 28 and hydrogen gas from the dehumidifier 22 is flowing through the dew point measurement line 32, the outlet valve 38 is closed (t13 in FIG. 3 ), and then the inlet valve 36 is closed (t14 in FIG. 3 ; inlet valve closing step). This results in hydrogen gas (dry gas) from the dehumidifier 22 being sealed in the portion 32a of the dew point measurement line 32. Then, the exhaust valve 29 is closed to stop the discharge of hydrogen gas from the dehumidifier 22 to the exhaust line 28 (t15; stop step). Then, while the dehumidifier 20 is stopped (from t15 onward or until t10 in FIG. 3 ), the inlet valve 36 and the outlet valve 38 are kept closed, maintaining the state in which hydrogen gas is sealed in the portion 32a of the dew point measurement line 32 (maintenance step). It should be noted that the order in which the exhaust valve 29, the inlet valve 36, and the outlet valve 38 are opened and closed does not have to be as described above, as long as hydrogen gas can be sealed in the portion 32a between the inlet valve 36 and the outlet valve 38. For example, hydrogen gas can also be sealed in the portion 32a between the inlet valve 36 and the outlet valve 38 by closing the inlet valve 36 and the outlet valve 38 immediately after closing the exhaust valve 29.

[0053] Furthermore, for example, in the case of the dehumidification device 20 shown in FIG. 2, in the above-mentioned maintenance step, dry gas (hydrogen gas, or an inert gas such as nitrogen or argon) supplied via a supply line 44 can be sealed in the portion 32a between the inlet valve 36 and the outlet valve 38 in the dew point measurement line 32.

[0054] In this case, the operating procedure when the dehumidifier 20 is stopped is, for example, as follows. As shown in FIG. 4 , the inlet valve 36 of the dew point measurement line 32 is closed (t24 in FIG. 4 ; inlet valve closing step) to block the inflow of hydrogen gas from the discharge line 28 to the dew point measurement line 32. At this time, the outlet valve 38 is open. Note that in FIG. 4 , the discharge valve 29 is closed at time t23 to stop the discharge of hydrogen gas from the dehumidifier 22 to the discharge line 28 (stop step), and then the inlet valve 36 of the dew point measurement line 32 is closed. However, the inlet valve 36 may be closed before the discharge valve 29 is closed. Thereafter, with the inlet valve 36 closed and the outlet valve 38 open, the supply valve 46 is opened (t25 in FIG. 4 ) to supply dry gas via the supply line 44 to the portion 32a of the dew point measurement line 32 between the inlet valve 36 and the outlet valve 38. Then, by closing the outlet valve 38 (t26 in FIG. 4 ), the dry gas from the dry gas supply unit 40 is sealed in the portion 32a of the dew point measurement line 32. After closing the outlet valve 38 at time t26, the supply valve 46 is closed to stop the supply of dry gas to the portion 32a of the dew point measurement line 32 via the supply line 44 (t27 in FIG. 4 ). Thereafter, while the dehumidifier 20 is stopped (from t27 onwards or until t20 in FIG. 4 ), the inlet valve 36 and the outlet valve 38 remain closed, maintaining the state in which the dry gas is sealed in the portion 32a of the dew point measurement line 32 (maintenance step).

[0055] Note that the order of opening and closing the exhaust valve 29, the inlet valve 36, the outlet valve 38, and the supply valve 46 does not have to be as described above, as long as the dry gas can be sealed in the portion 32a between the inlet valve 36 and the outlet valve 38. For example, the dry gas can also be sealed in the portion 32a between the inlet valve 36 and the outlet valve 38 by closing the inlet valve 36 and opening the supply valve 46 immediately after closing the exhaust valve 29.

[0056] As described above, when dry gas (hydrogen gas from the dehumidifier 22 or dry gas from the dry gas supply unit 40) is sealed in the portion 32a of the dew point measurement line 32, the dehumidifier 22 can be restarted, for example, by the following procedure. First, the exhaust valve 29 is opened to resume the discharge of hydrogen gas from the dehumidifier 22 to the exhaust line 28 (t10 in FIG. 3 and t20 in FIG. 4). Then, the inlet valve 36 and the outlet valve 38 are opened in this order (t11 to t12 in FIG. 3 and t21 to t22 in FIG. 4). This allows a portion of the hydrogen gas from the dehumidifier 22 to flow through the dew point measurement line 32, and measurement of the hydrogen gas dew point using the dew point meter 34 can be resumed. In the procedure for restarting the dehumidifier, the order in which the exhaust valve 29, inlet valve 36, outlet valve 38, and / or supply valve 46 are opened and closed does not have to be as described above.

[0057] According to the method of the above embodiment, a state in which dry gas (hydrogen gas from the dehumidifier 22 or dry gas from the dry gas supply unit 40) is sealed in the portion 32a of the dew point measurement line 32 between the inlet valve 36 and the outlet valve 38 can be maintained while the dehumidifier 22 is stopped. Therefore, the dew point at the dew point meter installation location can be maintained low while the dehumidifier 22 is stopped, so that the dew point at the dew point meter installation location can be quickly brought within the range of the operating conditions when the dehumidifier 22 is restarted. Therefore, appropriate dew point measurement by the dew point meter 34 can be quickly started when the dehumidifier 22 is restarted.

[0058] In some embodiments, in the above-mentioned maintenance step, dry gas (hydrogen gas or inert gas from the dry gas supply unit 40) may be continuously flowed into the portion 32a of the dew point measurement line 32 between the inlet valve 36 and the outlet valve 38, so as to maintain the dew point meter installation portion of the dew point measurement line 32 filled with dry gas.

[0059] For example, in the case of the dehumidification device 20 shown in FIG. 2, in the above-mentioned maintenance step, the inlet valve 36 of the dew point measurement line 32 is closed and the outlet valve 38 is open, and dry gas is continuously supplied to the dew point measurement line 32 via the supply line 44, thereby allowing dry gas to continue to flow through the portion 32a of the dew point measurement line 32.

[0060] In this case, the operating procedure when the dehumidifier 20 is stopped is, for example, as follows. As shown in FIG. 5 , the inlet valve 36 of the dew point measurement line 32 is closed (t34 in FIG. 5 ; inlet valve closing step) to block the inflow of hydrogen gas from the discharge line 28 to the dew point measurement line 32. At this time, the outlet valve 38 is open. Note that in FIG. 5 , the discharge valve 29 is closed at time t33 to stop the discharge of hydrogen gas from the dehumidifier 22 to the discharge line 28 (stop step), and then the inlet valve 36 of the dew point measurement line 32 is closed. However, the inlet valve 36 may be closed before the discharge valve 29 is closed. Alternatively, the discharge valve 29 and the inlet valve 36 may be closed simultaneously. Thereafter, with the inlet valve 36 closed and the outlet valve 38 open, the supply valve 46 is opened (t35 in FIG. 5 ), and dry gas is supplied via the supply line 44 to the portion 32a of the dew point measurement line 32 between the inlet valve 36 and the outlet valve 38. Then, thereafter, while the dehumidifier 20 is stopped (the period from t35 onwards or up to t30 in Figure 5), dry gas continues to be supplied to the dew point measurement line 32 via the supply line 44 with the inlet valve 36 closed and the outlet valve 38 open (maintenance step).

[0061] Note that the order of opening and closing the exhaust valve 29, the inlet valve 36, the outlet valve 38, and the supply valve 46 does not have to be the same as described above, as long as the dry gas can be continuously supplied to the portion 32 a between the inlet valve 36 and the outlet valve 38. For example, the dry gas can also be continuously supplied to the portion 32 a between the inlet valve 36 and the outlet valve 38 by closing the inlet valve 36 and opening the supply valve 46 immediately after closing the exhaust valve 29.

[0062] As described above, when the dehumidifier 22 is restarted while the dry gas (dry gas from the dry gas supply unit 40) continues to flow through the dew point measurement line 32, the following procedure is performed, for example. First, the exhaust valve 29 is opened to resume the discharge of hydrogen gas from the dehumidifier 22 to the exhaust line 28 (t30 in FIG. 5 ). Then, the supply valve 46 is closed and the inlet valve 36 is opened (t31 to t32 in FIG. 5 ). This allows a portion of the hydrogen gas from the dehumidifier 22 to flow through the dew point measurement line 32, and measurement of the dew point of the hydrogen gas using the dew point meter 34 can be resumed. In the procedure for restarting the dehumidifier, the order in which the exhaust valve 29, inlet valve 36, outlet valve 38, and / or supply valve 46 are opened and closed does not have to be as described above.

[0063] According to the method of the above embodiment, while the dehumidifier 22 is stopped, dry gas (such as hydrogen gas or an inert gas) continues to be supplied to the dew point measurement line 32 via the supply line 44 with the inlet valve 36 closed. This allows the dew point meter installation section of the dew point measurement line 32 to be filled with dry gas (such as hydrogen gas or an inert gas) while the dehumidifier 22 is stopped. This allows the dew point at the dew point meter installation section to be maintained low while the dehumidifier 22 is stopped. Therefore, when the dehumidifier 22 is restarted, the dew point at the dew point meter installation section can be quickly brought within the range of the operating conditions. Therefore, when the dehumidifier 22 is restarted, appropriate dew point measurement by the dew point meter can be quickly started.

[0064] In the above-mentioned maintenance step, for example, as described with reference to Figures 2 and 4, when dry gas from the dry gas supply unit 40 is sealed in the portion 32a of the dew point measurement line 32 between the inlet valve 36 and the outlet valve 38, the supply valve 46 and / or the outlet valve 38 may be operated based on the dew point measurement value of the dew point meter 34, so as to maintain the dew point meter installation portion of the dew point measurement line 32 filled with dry gas.

[0065] Specifically, for example, after sealing dry gas from the dry gas supply unit 40 in the portion 32a of the dew point measurement line 32 between the inlet valve 36 and the outlet valve 38 in the procedure described above, while the dehumidifier 20 is stopped (the period from t27 onwards or up to t20 in Figure 4), the state in which dry gas is sealed in the portion 32a of the dew point measurement line 32 is maintained (maintenance step), the supply valve 46 and / or the outlet valve 38 can be operated, for example, in the following manner.

[0066] With the dry gas sealed in the portion 32a of the dew point measurement line 32, the dew point at the dew point installation portion is measured by the dew point meter 34. When the dew point rises and becomes greater than the first threshold, the outlet valve 38 and the supply valve 46 are opened in this order, and the dry gas is supplied to the dew point measurement line 32 via the supply line 44. While the dry gas is being supplied to the dew point measurement line 32 in this manner, the dew point at the dew point installation portion is measured by the dew point meter 34, and when the dew point falls to a second threshold that is lower than the first threshold, the outlet valve 38 and the supply valve 46 are closed in this order, and the dry gas is again sealed in the portion 32a of the dew point measurement line 32.

[0067] According to the above-described method, the supply valve 46 and / or the outlet valve 38 provided on the supply line 44 are operated based on the dew point measurement value in the portion of the dew point measurement line 32 containing the dry gas (hydrogen gas or inert gas) during the dehumidifier 22 shutdown period. By appropriately operating the supply valve 46 and / or the outlet valve 38, dry gas can be appropriately supplied to the dew point measurement line 32 to maintain the dew point at the dew point meter within a desired range (in the above example, a range between the second threshold and the first threshold). This maintains a low dew point at the dew point meter during the dehumidifier 22 shutdown period. Therefore, when the dehumidifier 22 is restarted, the dew point at the dew point meter can be quickly brought within the operating conditions. Therefore, when the dehumidifier 22 is restarted, the dew point meter 34 can quickly begin appropriate dew point measurement.

[0068] In some embodiments, the dew point meter 34 may be a capacitance type dew point meter.

[0069] While capacitance dew point meters have the advantage of being able to measure dew points with high accuracy over a wider temperature range than other types of dew point meters (e.g., chilled mirror dew point meters), they are characterized by difficulty in properly measuring the dew point in high humidity conditions. In this regard, in the above-described embodiment, in the dehumidifier 20 equipped with a capacitance dew point meter as the dew point meter 34, as already described, the dew point at the dew point meter installation location on the dew point measurement line 32 can be maintained low while the dehumidifier 22 is stopped. Therefore, when the dehumidifier 22 is restarted, the dew point at the dew point meter installation location can be quickly brought within the operating conditions. Therefore, when the dehumidifier 22 is restarted, the dew point meter can quickly begin measuring the dew point properly.

[0070] The contents described in each of the above embodiments can be understood, for example, as follows.

[0071] [1] A method for operating a dehumidifier (20) according to at least one embodiment of the present invention is a method for operating a dehumidifier for dehumidifying hydrogen gas produced by a hydrogen production apparatus (10), the dehumidifier comprising: a dehumidifier (22) for dehumidifying moisture contained in hydrogen gas; a discharge line (28) for discharging the hydrogen gas dehumidified by the dehumidifier from the dehumidifier; a dew point measurement line (32) connected to the discharge line; a dew point meter (34) provided in the dew point measurement line; an inlet valve (36) provided in the dew point measurement line at a position closer to a connection portion (30) with the discharge line than the dew point meter; and an outlet valve (38) provided in the dew point measurement line at a position opposite the inlet valve across the dew point meter; and a stop step of stopping the discharge of the hydrogen gas from the dehumidifier to the discharge line. and a maintaining step of maintaining a state in which a dew point meter installation portion of the dew point measurement line, which includes at least the installation location of the dew point meter, is filled with dry gas when the discharge of the hydrogen gas from the dehumidifier to the discharge line is stopped.

[0072] According to the method [1] above, the dew point meter installation section in the dew point measurement line is kept filled with dry gas when the dehumidifier is stopped (i.e., during the dehumidifier's shutdown period), so the dew point at the dew point meter installation section can be kept low even during the dehumidifier's shutdown period when dehumidified hydrogen gas is not being discharged from the dehumidifier. Therefore, when the dehumidifier is restarted, the dew point at the dew point meter installation section can be quickly brought within the range of the operating conditions, and therefore appropriate dew point measurement by the dew point meter can be quickly started.

[0073] [2] In some embodiments, in the method of [1] above, the method of operating the dehumidifier includes a step of resuming the discharge of the hydrogen gas from the dehumidifier to the discharge line in a state where the dew point meter installation section of the dew point measurement line is filled with the dry gas.

[0074] According to the method [2] above, after the dehumidifier is stopped, the discharge of hydrogen gas from the dehumidifier to the exhaust line is resumed (i.e., the dehumidifier is restarted) while the dew point meter installation section of the dew point measurement line is filled with dry gas. In other words, the discharge of hydrogen gas from the dehumidifier to the exhaust line is resumed while the dew point at the dew point meter installation section is maintained low. Therefore, by opening the inlet valve and outlet valve in this state, hydrogen gas from the dehumidifier can be introduced into the dew point measurement line without causing a significant increase in the dew point at the dew point meter installation section. Therefore, when the dehumidifier is restarted, appropriate dew point measurement by the dew point meter can be started promptly.

[0075] [3] In some embodiments, in the configuration of [1] or [2] above, the configuration further comprises a step of sealing the hydrogen gas in a portion of the dew point measurement line between the inlet valve and the outlet valve by closing the inlet valve and the outlet valve when the discharge of the hydrogen gas from the dehumidifier to the discharge line is stopped, and in the maintaining step, the inlet valve and the outlet valve are maintained in a closed state.

[0076] According to the configuration [3] above, when the dehumidifier is shut down and the discharge of hydrogen gas from the dehumidifier to the exhaust line is stopped, the dew point meter installation section of the dew point measurement line is filled with hydrogen gas from the dehumidifier, and the outlet valve and inlet valve are closed to seal hydrogen gas (hydrogen gas dehumidified and dried by the dehumidifier) ​​in the section between the inlet and outlet valves of the dew point meter side line. Then, by keeping the inlet and outlet valves closed after the discharge of hydrogen gas from the dehumidifier to the exhaust line is stopped, dry hydrogen gas (dry gas) can be maintained in the section between the inlet and outlet valves while the dehumidifier is shut down. Therefore, the dew point at the dew point meter installation section can be maintained low during the dehumidifier's shutdown period, and the dew point at the dew point meter installation section can be quickly brought within the operating conditions when the dehumidifier is restarted. Therefore, appropriate dew point measurement by the dew point meter can be quickly initiated when the dehumidifier is restarted.

[0077] [4] In some embodiments, the method of [3] above further comprises an inlet valve closing step of closing the inlet valve when the discharge of the hydrogen gas from the dehumidifier to the discharge line is stopped, wherein in the inlet valve closing step, the outlet valve is closed while hydrogen gas is being discharged from the dehumidifier to the discharge line, and then the inlet valve is closed, thereby sealing the hydrogen gas as the dry gas in the portion (32a) of the dew point measurement line between the inlet valve and the outlet valve, and in the stop step, after the inlet valve closing step, the discharge of the hydrogen gas from the dehumidifier to the discharge line is stopped.

[0078] According to the method [4] above, when the dehumidifier is shut down, immediately before the dehumidifier stops discharging hydrogen gas from the dehumidifier to the exhaust line, the outlet valve and the inlet valve are closed in this order while hydrogen gas from the dehumidifier is still flowing through the dew point meter-mounted section of the dew point measurement line. This seals hydrogen gas (hydrogen gas dehumidified and dried by the dehumidifier) ​​in the section between the inlet and outlet valves of the dew point meter-side line. Then, by keeping the inlet and outlet valves closed after the dehumidifier stops discharging hydrogen gas to the exhaust line, dry hydrogen gas (dry gas) can be maintained in the section between the inlet and outlet valves during the dehumidifier's shutdown period. Therefore, the dew point at the dew point meter-mounted section can be maintained low during the dehumidifier's shutdown period. Therefore, when the dehumidifier is restarted, the dew point at the dew point meter-mounted section can be quickly brought within the operating conditions. Therefore, when the dehumidifier is restarted, appropriate dew point measurement by the dew point meter can be quickly initiated.

[0079] [5] In some embodiments, in the method of [1] or [2] above, the method of operating the dehumidifier comprises: an inlet valve closing step of closing the inlet valve when the discharge of the hydrogen gas from the dehumidifier to the discharge line is stopped; and a supply step of supplying hydrogen gas or an inert gas as the dry gas to the dew point measurement line through a supply line (44) connected to a portion of the dew point measurement line between the inlet valve and the dew point meter while the inlet valve is closed.

[0080] According to the method [5] above, when the dehumidifier is stopped, with the outlet valve open and the inlet valve closed, hydrogen gas or inert gas (dry gas) is supplied to the dew point measurement line through a supply line connected to a portion of the dew point measurement line between the inlet valve and the dew point meter. This allows the dew point meter installation area to be filled with hydrogen gas or inert gas (dry gas) while the dehumidifier is stopped. This allows the dew point at the dew point meter installation area to be maintained low during the dehumidifier's stopped period, so that when the dehumidifier is restarted, the dew point at the dew point meter installation area can be quickly brought within the operating conditions. Therefore, when the dehumidifier is restarted, the dew point meter can quickly begin appropriate dew point measurement.

[0081] [6] In some embodiments, in the method of [5] above, in the maintaining step, the dry gas continues to be supplied to the dew point measurement line via the supply line with the inlet valve closed and the outlet valve open.

[0082] According to the method [6] above, while the dehumidifier is stopped, hydrogen gas or inert gas (dry gas) is continuously supplied to the dew point measurement line through the supply line with the inlet valve closed and the outlet valve open. This allows the dew point meter installation area to be filled with hydrogen gas or inert gas (dry gas) while the dehumidifier is stopped. This allows the dew point at the dew point meter installation area to be maintained low while the dehumidifier is stopped, so that when the dehumidifier is restarted, the dew point at the dew point meter installation area can be quickly brought within the operating conditions. Therefore, when the dehumidifier is restarted, appropriate dew point measurement by the dew point meter can be quickly started.

[0083] [7] In some embodiments, in the method of [5] above, the method of operating the dehumidifier includes a step of sealing the dry gas in the portion of the dew point measurement line between the inlet valve and the outlet valve by closing the outlet valve while the dew point measurement line is filled with the dry gas from the supply line, and in the maintaining step, the inlet valve and the outlet valve are maintained in a closed state.

[0084] According to the method [7] above, the inlet valve is closed and the dew point measurement line is filled with hydrogen gas or inert gas (dry gas) from the supply line. By closing the outlet valve, hydrogen gas or inert gas (dry gas) is sealed in the section between the inlet and outlet valves, and the inlet and outlet valves are maintained closed. This allows the hydrogen gas or inert gas (dry gas) to be sealed in the section of the dew point measurement line between the inlet and outlet valves during periods when the dehumidifier is not in operation. Furthermore, since there is no need to continue supplying hydrogen gas or inert gas via the supply line to maintain the section of the dew point measurement line filled with dry gas, hydrogen gas or inert gas can be saved. This allows the dew point at the dew point meter to be maintained low during periods when the dehumidifier is not in operation. Therefore, when the dehumidifier is restarted, the dew point at the dew point meter can be quickly brought within the operating conditions. Therefore, appropriate dew point measurement by the dew point meter can be quickly initiated when the dehumidifier is restarted.

[0085] [8] In some embodiments, in the method of [7] above, the method of operating the dehumidifier includes a step of measuring the dew point of the dry gas present in the portion of the dew point measurement line using the dew point meter, and in the maintaining step, while maintaining the inlet valve and the outlet valve in a closed state, operating a supply valve (46) provided in the supply line based on the measured value of the dew point.

[0086] According to the method [8] above, during periods when the dehumidifier is stopped, a supply valve provided in the supply line is operated based on the dew point measurement value in the portion of the dew point measurement line filled with hydrogen gas or inert gas (dry gas). By appropriately operating the supply valve, dry gas can be appropriately supplied to the dew point measurement line, thereby maintaining the dew point at the dew point meter installation location within a desired range. This allows the dew point at the dew point meter installation location to be maintained low during periods when the dehumidifier is stopped, so that when the dehumidifier is restarted, the dew point at the dew point meter installation location can be quickly brought within the operating conditions. Therefore, when the dehumidifier is restarted, appropriate dew point measurement by the dew point meter can be quickly initiated.

[0087] [9] In some embodiments, in the method according to any one of [1] to [8] above, the dew point meter is a capacitance type dew point meter.

[0088] While capacitance dew point meters have the advantage of being able to measure dew points with high accuracy over a wider temperature range than other types of dew point meters (e.g., chilled mirror dew point meters), they are characterized by difficulty in properly measuring the dew point in high humidity conditions. In this regard, the method described in [9] above allows a dehumidifier equipped with a capacitance dew point meter to maintain a low dew point at the dew point meter installation location on the dew point measurement line during periods when the dehumidifier is not in operation, as described in [1] above. Therefore, when the dehumidifier is restarted, the dew point at the dew point meter installation location can be quickly brought within the operating conditions. Therefore, when the dehumidifier is restarted, appropriate dew point measurement using the dew point meter can be quickly initiated.

[0089]

[10] A control device (50) for a dehumidifier according to at least one embodiment of the present invention is a control device for controlling the operation of a dehumidifier (20) for dehumidifying hydrogen gas produced by a hydrogen production device (10), wherein the dehumidifier includes: a dehumidifier (22) for dehumidifying moisture contained in the hydrogen gas; an exhaust line (28) for exhausting the hydrogen gas dehumidified by the dehumidifier from the dehumidifier; a dew point measurement line (32) connected to the exhaust line; a dew point meter (34) provided on the dew point measurement line; an inlet valve (36) provided on the dew point measurement line at a position closer to the connection portion (30) with the exhaust line than the dew point meter; and an outlet valve (38) provided on the dew point measurement line at a position opposite the inlet valve across the dew point meter. The control device is configured to operate the opening and closing of the inlet valve or the outlet valve so that, when the discharge of the hydrogen gas from the dehumidifier to the discharge line is stopped, the dew point meter installation section of the dew point measurement line, which includes at least the installation location of the dew point meter, is maintained filled with dry gas.

[0090] According to the configuration

[10] above, the dew point meter installation section in the dew point measurement line is kept filled with dry gas when the dehumidifier is stopped, so the dew point at the dew point meter installation section can be kept low even during periods when the dehumidifier is stopped and dehumidified hydrogen is not being discharged from the dehumidifier. Therefore, when the dehumidifier is restarted, the dew point at the dew point meter installation section can be quickly brought within the range of the operating conditions, and therefore appropriate dew point measurement by the dew point meter can be quickly started.

[0091]

[11] A dehumidification device (20) according to at least one embodiment of the present invention is a dehumidification device for dehumidifying hydrogen gas produced in a hydrogen production device (10), and comprises: a dehumidifier (22) for dehumidifying moisture contained in the hydrogen gas; an exhaust line (28) for exhausting the hydrogen gas dehumidified by the dehumidifier from the dehumidifier; a dew point measurement line (32) connected to the exhaust line; a dew point meter (34) provided in the dew point measurement line; an inlet valve (36) provided in the dew point measurement line at a position closer to the connection portion (30) with the exhaust line than the dew point meter; and an outlet valve (38) provided in the dew point measurement line at a position opposite the inlet valve across the dew point meter, and is configured so that the hydrogen gas that has passed through the outlet valve in the dew point measurement line is released into the atmosphere.

[0092] In a dehumidifier configured as described above in

[11] , in which hydrogen gas is released into the atmosphere through a dew point measurement line connected to the exhaust line, if hydrogen from the dehumidifier stops flowing through the dew point measurement line when the dehumidifier is shut down, atmospheric air (humid air) may enter the dew point measurement line, causing the dew point at the dew point meter to rise. In this regard, the configuration described above in

[11] provides inlet and outlet valves on both sides of the dew point meter in the dew point measurement line. By appropriately opening and closing the inlet and outlet valves when the dehumidifier is shut down, the dew point at the dew point meter can be kept filled with dry gas. Therefore, even during dehumidifier shutdown periods when dehumidified hydrogen is not being discharged from the dehumidifier, the dew point at the dew point meter can be maintained low. Therefore, when the dehumidifier is restarted, the dew point at the dew point meter can be quickly brought within the operating conditions, allowing the dew point meter to quickly begin appropriate dew point measurement.

[0093]

[12] A hydrogen production facility (1) according to at least one embodiment of the present invention comprises: a hydrogen production device (10); and a dehumidification device (20) according to the above

[11] configured to dehumidify the hydrogen gas produced by the hydrogen production device.

[0094] According to the configuration

[12] above, an inlet valve and an outlet valve are provided on both sides of the dew point meter in the dew point measurement line. Therefore, when the dehumidifier is stopped, the inlet valve and the outlet valve can be appropriately opened and closed to keep the dew point meter-mounted portion of the dew point measurement line filled with dry gas. Therefore, even during periods when the dehumidifier is stopped and dehumidified hydrogen is not being discharged from the dehumidifier, the dew point at the dew point meter-mounted portion can be maintained low. Therefore, when the dehumidifier is restarted, the dew point at the dew point meter-mounted portion can be quickly brought within the operating conditions, allowing the dew point meter to quickly begin appropriate dew point measurement.

[0095] The above describes an embodiment of the present invention, but the present invention is not limited to the above-described embodiment, and also includes forms in which the above-described embodiment is modified, or forms in which these forms are appropriately combined.

[0096] In this specification, expressions expressing relative or absolute arrangements, such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial," not only strictly express such arrangements, but also express a state in which there is a relative displacement with a tolerance or an angle or distance to the extent that the same function is obtained. For example, expressions expressing that things are in an equal state, such as "identical," "equal," and "homogeneous," not only express a state in which there is a strict equivalence, but also express a state in which there is a tolerance or a difference to the extent that the same function is obtained. Furthermore, in this specification, expressions expressing shapes such as a rectangular shape or a cylindrical shape not only express shapes such as a rectangular shape or a cylindrical shape in the strict geometric sense, but also express shapes including concave and convex portions, chamfered portions, etc., to the extent that the same effect is obtained. Furthermore, in this specification, the expressions "comprise," "include," or "have" a component are not exclusive expressions that exclude the presence of other components.

[0097] REFERENCE SIGNS LIST 1 Hydrogen production facility 10 Hydrogen production device 12 Water electrolysis device 14 Gas-liquid separator 16 Hydrogen line 20 Dehumidifier 22 Dehumidifier 24 Inlet line 25 Inlet valve 26 Vent line 27 Vent valve 28 Discharge line 29 Discharge valve 30 Connection part 32 Dew point measurement line 32a part 34 Dew point meter 36 Inlet valve 38 Outlet valve 40 Dry gas supply part 42 Dry gas storage part 44 Supply line 46 Supply valve 50 Control device

Claims

1. A method for operating a dehumidifying device for dehumidifying hydrogen gas produced by a hydrogen production device, the dehumidifying device comprising: a dehumidifier for dehumidifying moisture contained in the hydrogen gas; a discharge line for discharging the hydrogen gas dehumidified by the dehumidifier from the dehumidifier; a dew point measurement line connected to the discharge line; a dew point meter provided in the dew point measurement line; an inlet valve provided at a position on the dew point measurement line closer to the connection portion with the discharge line than the dew point meter; and an outlet valve provided at a position on the dew point measurement line on the opposite side of the dew point meter, the method comprising: a stop step of stopping the discharge of the hydrogen gas from the dehumidifier to the discharge line; and a maintenance step of maintaining a state in which at least a dew point meter installation portion including the installation location of the dew point meter in the dew point measurement line is filled with a dry gas when the discharge of the hydrogen gas from the dehumidifier to the discharge line is stopped.

2. The method for operating a dehumidifying device according to claim 1, further comprising a step of restarting the discharge of the hydrogen gas from the dehumidifier to the discharge line while the dew point meter installation portion of the dew point measurement line is filled with the dry gas.

3. The method for operating a dehumidifying device according to claim 1 or 2, comprising a step of closing the inlet valve and the outlet valve to enclose the hydrogen gas in a portion between the inlet valve and the outlet valve of the dew point measurement line when stopping the discharge of the hydrogen gas from the dehumidifier to the discharge line, and in the maintenance step, maintaining the state in which the inlet valve and the outlet valve are closed.

4. The method for operating a dehumidifying device according to claim 3, comprising an inlet valve closing step of closing the inlet valve when stopping the discharge of the hydrogen gas from the dehumidifier to the discharge line, in the inlet valve closing step, closing the outlet valve while the hydrogen gas is being discharged from the dehumidifier to the discharge line, and then closing the inlet valve to enclose the hydrogen gas as the dry gas in a portion between the inlet valve and the outlet valve of the dew point measurement line, and in the stop step, stopping the discharge of the hydrogen gas from the dehumidifier to the discharge line after the inlet valve closing step.

5. An inlet valve closing step of closing the inlet valve when discharging of the hydrogen gas from the dehumidifier to the discharge line is stopped, and a supply step of supplying hydrogen gas or an inert gas as the dry gas to the dew point measurement line via a supply line connected to a portion between the inlet valve and the dew point meter in the dew point measurement line in a state where the inlet valve is closed. The operation method of the dehumidifying device according to claim 1 or 2.

6. In the maintaining step, the dry gas is continuously supplied to the dew point measurement line via the supply line in a state where the inlet valve is closed and the outlet valve is open. The operation method of the dehumidifying device according to claim 5.

7. A step of enclosing the dry gas in a portion between the inlet valve and the outlet valve of the dew point measurement line by closing the outlet valve in a state where the dew point measurement line is filled with the dry gas from the supply line. In the maintaining step, the inlet valve and the outlet valve are maintained in a closed state. The operation method of the dehumidifying device according to claim 5.

8. A step of measuring the dew point of the dry gas present in the portion of the dew point measurement line using the dew point meter. In the maintaining step, while maintaining the inlet valve and the outlet valve in a closed state, a supply valve provided in the supply line is operated based on the measured value of the dew point. The operation method of the dehumidifying device according to claim 7.

9. The dew point meter is a capacitance type dew point meter. The operation method of the dehumidifying device according to claim 1 or 2.

10. A control device for controlling the operation of a dehumidifying device for dehumidifying hydrogen gas produced by a hydrogen production device, wherein the dehumidifying device includes: a dehumidifier for dehumidifying moisture contained in the hydrogen gas; a discharge line for discharging the hydrogen gas dehumidified by the dehumidifier from the dehumidifier; a dew point measurement line connected to the discharge line; a dew point meter provided in the dew point measurement line; an inlet valve provided at a position on the dew point measurement line closer to the connection portion with the discharge line than the dew point meter; and an outlet valve provided at a position on the dew point measurement line on the opposite side of the dew point meter with the dew point meter interposed therebetween. The control device for the dehumidifying device is configured to operate the opening and closing of the inlet valve or the outlet valve so that a state in which at least a dew point meter installation portion including the installation location of the dew point meter in the dew point measurement line is filled with a dry gas is maintained when the discharge of the hydrogen gas from the dehumidifier to the discharge line is stopped.

11. A dehumidifying device for dehumidifying hydrogen gas produced by a hydrogen production device, comprising: a dehumidifier for dehumidifying moisture contained in the hydrogen gas; a discharge line for discharging the hydrogen gas dehumidified by the dehumidifier from the dehumidifier; a dew point measurement line connected to the discharge line; a dew point meter provided in the dew point measurement line; an inlet valve provided at a position on the dew point measurement line closer to the connection portion with the discharge line than the dew point meter; and an outlet valve provided at a position on the dew point measurement line on the opposite side of the dew point meter with the dew point meter interposed therebetween. The dehumidifying device is configured such that the hydrogen gas passing through the outlet valve in the dew point measurement line is released to the atmosphere.

12. A hydrogen production facility comprising: a hydrogen production device; and the dehumidifying device according to claim 11 configured to dehumidify the hydrogen gas produced by the hydrogen production device.

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