Abnormity diagnostic device and abnormity diagnostic method and abnormity diagnostic program

Abstract

To diagnose abnormality in a solid polymer electrolyte membrane without reducing the operating rate of a water electrolysis apparatus.SOLUTION: An information processing device (2) includes a determination unit (200) that includes a voltage determination unit (201) that determines whether or not a voltage drop of a voltage threshold or more has occurred for each electrolytic cell, and an abnormality diagnostic unit (207) that diagnoses abnormality in a solid polymer electrolyte membrane based on the determination result from the determination unit (200).SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an abnormality diagnosis device for a water electrolysis device that electrolyzes water. [Background technology]

[0002] Conventionally, water electrolysis devices have been put to practical use, which electrolyze pure water by applying a voltage to a solid polymer electrolyte membrane and passing a current through it, generating hydrogen (H2) on the cathode side and oxygen (O2) on the anode side. In this type of water electrolysis device, when electrolysis operations are repeated, the solid polymer electrolyte membrane repeatedly swells and shrinks, which can damage the solid polymer electrolyte membrane.

[0003] Microshort circuits are known to be one of the causes of damage to solid polymer electrolyte membranes. A microshort circuit is a phenomenon in which conductive fibers, such as carbon fibers and metal fibers, which are the constituent materials of electrolysis cells, penetrate the solid polymer electrolyte membrane and cause a short circuit. When a microshort circuit occurs, a current flows through the conductive fibers during electrolysis operation, generating heat, and the solid polymer electrolyte membrane around the conductive fibers is dissolved. As a result, pinholes are formed in the solid polymer electrolyte membrane, and water or gas leaks through the pinholes.

[0004] As a technique for diagnosing such an abnormality in a solid polymer electrolyte membrane, Patent Document 1 proposes a technique in which a voltage is applied to an electrolysis cell stack using an auxiliary power supply when electrolysis operation is stopped, and the presence or absence of a micro-short circuit is determined. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2020-196906 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the above-mentioned conventional techniques, it is necessary to stop the electrolysis operation when determining whether or not a micro-short circuit exists, which causes a problem of a decrease in the availability of the water electrolysis device.

[0007] One aspect of the present invention has been made in consideration of the above-mentioned problems in the conventional technology, and has an object to diagnose an abnormality in a solid polymer electrolyte membrane without reducing the operating rate of a water electrolysis device. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, an abnormality diagnosis device according to one embodiment of the present invention is an abnormality diagnosis device for a water electrolysis apparatus including an electrolytic cell in which a plurality of electrolytic cells, each including a solid polymer electrolyte membrane, are connected in series, and includes a judgment unit including a voltage judgment unit that judges for each electrolytic cell whether a voltage drop of a predetermined threshold or more has occurred in the electrolytic cell based on the amount of voltage change for each electrolytic cell during a predetermined period of time during electrolysis operation, and an abnormality diagnosis unit that diagnoses an abnormality in the solid polymer electrolyte membrane based on the judgment result of the judgment unit.

[0009] In order to solve the above-mentioned problems, an abnormality diagnosis method according to one embodiment of the present invention is a method for diagnosing an abnormality in a water electrolysis apparatus including an electrolytic cell in which a plurality of electrolytic cells, each including a solid polymer electrolyte membrane, are connected in series, and includes a determination step including a voltage determination step of determining for each electrolytic cell whether a voltage drop of equal to or greater than a predetermined voltage threshold has occurred in the electrolytic cell based on an amount of voltage change for each electrolytic cell during a predetermined period of electrolysis operation, and an abnormality diagnosis step of diagnosing an abnormality in the solid polymer electrolyte membrane based on a determination result of the determination step. Effect of the Invention

[0010] According to one aspect of the present invention, it is possible to diagnose an abnormality in a solid polymer electrolyte membrane without reducing the availability of a water electrolysis device. [Brief description of the drawings]

[0011] [Figure 1]1 is a schematic diagram showing a schematic configuration of a water electrolysis system according to an embodiment of the present invention. FIG. [Diagram 2] FIG. 2 is a block diagram showing an example of the configuration of a main part of the water electrolysis system shown in FIG. 1. [Diagram 3] 3 is a flowchart showing an example of an abnormality diagnosis process executed by the information processing device shown in FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] An embodiment of the present invention will be described below with reference to Figures 1 to 3. However, the following description is an example of an abnormality diagnosis device according to the present invention, and the technical scope of the present invention is not limited to the illustrated example.

[0013] [Outline of the water electrolysis system 100] First, an overview of a water electrolysis system 100 according to one embodiment of the present invention will be described with reference to Fig. 1. Fig. 1 is a block diagram showing a schematic configuration of the water electrolysis system 100 according to this embodiment. The water electrolysis system 100 according to this embodiment is a solid polymer water electrolysis system that electrolyzes pure water by applying a voltage to a solid polymer electrolyte membrane 102 to pass a current therethrough, thereby generating hydrogen (H2) and oxygen (O2).

[0014] 1, the water electrolysis system 100 includes a water electrolysis apparatus 1 equipped with an electrolytic cell 10 in which a plurality of electrolytic cells 101, each of which has a solid polymer electrolyte membrane 102, are connected in series, and an information processing device (abnormality diagnosis device) 2 that controls the water electrolysis apparatus 1. The information processing device 2 comprehensively controls the operation of the water electrolysis apparatus 1, and also executes abnormality diagnosis processing to diagnose whether or not there is an abnormality in the solid polymer electrolyte membrane 102.

[0015] The information processing device 2 performs the abnormality diagnosis process to diagnose an abnormality in the solid polymer electrolyte membrane 102 without stopping the electrolysis operation of the electrolytic cell 10. Therefore, according to the water electrolysis system 100, it is possible to diagnose an abnormality in the solid polymer electrolyte membrane 102 without reducing the operation rate of the water electrolysis apparatus 1.

[0016] [Configuration of water electrolysis system 100] Next, with reference to FIG. 2 in addition to FIG. 1, a configuration example of the water electrolysis device 1 and the information processing device 2 included in the water electrolysis system 100 will be described.

[0017] (Water electrolysis device 1) 1, the water electrolysis apparatus 1 includes an electrolytic cell 10, a hydrogen gas-liquid separator 11, an oxygen gas-liquid separator 12, a water circulation line 13, an ion exchanger 14, and a pure water tank 15. The water electrolysis apparatus 1 also includes a rectifier 16 that supplies electric power to the electrolytic cell 10.

[0018] The water circulation line 13 is a pipe for circulating water from the oxygen gas-liquid separator 12 to the electrolytic cell 10. The water circulation line 13 is provided with a circulation pump 30 for circulating water and a circulation water cooler 31 for cooling the circulation water before being supplied to the electrolytic cell 10. The circulation water circulating through the water circulation line 13 is adjusted to a predetermined temperature (e.g., 80°C) by the circulation water cooler 31 and supplied to the electrolytic cell 10. In the illustrated example, the circulation water cooler 31 is provided downstream of the circulation pump 30. That is, the circulation water cooler 31 is provided between the circulation pump 30 and the electrolytic cell 10. By providing the circulation water cooler 31 downstream of the circulation pump 30 in this way, the circulation water can easily pass through the circulation water cooler 31 by utilizing the discharge pressure of the circulation pump 30. However, it is also possible to provide the circulation water cooler 31 upstream of the circulation pump 30.

[0019] Further, a circulating water flow meter 42 and a conductivity meter 43 are installed in the water circulation line 13. The circulating water flow meter 42 is a sensor that detects the flow rate of the circulating water circulating through the water circulation line 13, and outputs a detection signal to the information processing device 2. In the illustrated example, the circulating water flow meter 42 is installed downstream of the circulating water cooler 31, but the installation position of the circulating water flow meter 42 is not limited to this. The conductivity meter 43 is a sensor that detects the conductivity of the circulating water circulating through the water circulation line 13, and outputs a detection signal to the information processing device 2. In the illustrated example, the conductivity meter 43 is installed on the inlet side of the circulating water of the electrolytic cell 10, but the installation position of the conductivity meter 43 is not limited to this.

[0020] The electrolytic cell 10 electrolyzes water using a solid polymer electrolyte membrane 102 to generate hydrogen and oxygen. The electrolytic cell 10 is an electrolytic cell stack in which a plurality of electrolytic cells 101, each including a solid polymer electrolyte membrane 102, are connected in series. The electrolytic cell 10 is supplied with power (DC) required for water electrolysis from a rectifier 16. The power supplied to the electrolytic cell 10 can be power from a commercial power source, or can be renewable energy such as solar power generation or wind power generation, or surplus power thereof. The hydrogen generated at the cathode of the electrolytic cell 10 is sent to a hydrogen gas-liquid separator 11 in the form of a gas-liquid mixed water. The oxygen generated at the anode of the electrolytic cell 10 is sent to an oxygen gas-liquid separator 12 in the form of a gas-liquid mixed water.

[0021] A voltmeter 40 is attached to each of the electrolytic cells 101. The voltmeter 40 is a sensor that detects the voltage of each electrolytic cell 101 and outputs a detection signal to the information processing device 2. In addition, an ammeter 41 is attached to the electrolytic bath 10. The ammeter 41 is a sensor that detects the current flowing through the electrolytic bath 10 and outputs a detection signal to the information processing device 2.

[0022] The hydrogen gas-liquid separator 11 separates the hydrogen generated in the electrolytic cell 10 from the water. The hydrogen separated in the hydrogen gas-liquid separator 11 is cooled by a hydrogen cooler 32 and then supplied to a dehumidifier (not shown) or the like, where moisture is removed to produce a product gas. Meanwhile, the water separated in the hydrogen gas-liquid separator 11 is supplied to the pure water tank 15. A drainage flow meter 45 is installed in the piping connecting the hydrogen gas-liquid separator 11 and the pure water tank 15. The drainage flow meter 45 is a sensor that detects the flow rate (drainage amount) of water drained from the hydrogen gas-liquid separator 11, and outputs a detection signal to the information processing device 2.

[0023] The oxygen gas-liquid separator 12 separates the oxygen generated in the electrolytic cell 10 from water. The oxygen separated in the oxygen gas-liquid separator 12 is cooled by the oxygen cooler 33 and then exhausted, for example, to the atmosphere. A hydrogen concentration meter 44 is installed in a pipe connecting the oxygen gas-liquid separator 12 and the oxygen cooler 33. The hydrogen concentration meter 44 is a sensor that detects the hydrogen concentration contained in the oxygen generated in the electrolytic cell 10, specifically, the hydrogen concentration contained in the oxygen separated in the oxygen gas-liquid separator 12, and outputs a detection signal to the information processing device 2.

[0024] The pure water tank 15 is a water tank that stores water to be electrolyzed in the electrolytic cell 10. The pure water tank 15 stores water obtained by treating supply water (city water, etc.) newly supplied to the electrolytic cell 10 using the ion exchanger 14. The pure water tank 15 also stores water separated in the hydrogen gas-liquid separator 11. A supply pump 34 is installed in the piping that connects the pure water tank 15 and the oxygen gas-liquid separator 12 to send water from the pure water tank 15 to the oxygen gas-liquid separator 12. The water temporarily stored in the pure water tank 15 is sent to the oxygen gas-liquid separator 12 by the supply pump 34 in accordance with a preset level setting for the oxygen gas-liquid separator 12.

[0025] The water electrolysis device 1 is not limited to the above-mentioned configuration. As the water electrolysis device 1, a wide variety of known water electrolysis facilities including an electrolysis cell stack can be used.

[0026] (Information processing device 2) The information processing device 2 comprehensively controls the operation of the water electrolysis device 1. The information processing device 2 controls, for example, the rectifier 16 to supply power to the electrolytic cell 10 and controls the operation of the electrolytic cell 10. The information processing device 2 also executes an abnormality diagnosis process to diagnose whether or not there is an abnormality in the solid polymer electrolyte membrane 102.

[0027] Fig. 2 is a block diagram showing an example of the configuration of the main parts of the water electrolysis system 100 shown in Fig. 1. As shown in Fig. 2, the information processing device 2 includes a control unit 20 that controls each part of the information processing device 2, a communication unit 21 that enables the information processing device 2 to communicate with other devices (e.g., the water electrolysis device 1), and a storage unit 22 that stores data such as detection signals from the water electrolysis device 1 and various threshold values.

[0028] The communication unit 21 transmits and receives various signals in a wired or wireless manner. The information processing device 2 controls the water electrolysis device 1 through communication via the communication unit 21. The information processing device 2 also acquires detection signals from various sensors provided in the water electrolysis device 1 through communication via the communication unit 21. For example, the communication unit 21 outputs each detection signal acquired from the various sensors provided in the water electrolysis device 1 to the control unit 20. The communication unit 21 also outputs each detection signal to the storage unit 22, and stores them in the storage unit 22 as history information.

[0029] The control unit 20 includes a determination unit 200, an abnormality diagnosis unit 207, and an equipment control unit 208. The determination unit 200 includes a voltage determination unit 201, a current determination unit 202, a flow rate determination unit 203, a conductivity determination unit 204, a hydrogen concentration determination unit (concentration determination unit) 205, and a wastewater amount determination unit 206.

[0030] The voltage determination unit 201 determines for each electrolytic cell 101 whether a voltage drop of equal to or greater than a predetermined voltage threshold has occurred in the electrolytic cell 101 based on the amount of voltage change for each electrolytic cell 101 during a predetermined period during electrolysis operation (voltage determination step). If it is determined that no voltage drop of equal to or greater than the voltage threshold has occurred in the electrolytic cell 101, the voltage determination unit 201 outputs the determination result to the abnormality diagnosis unit 207. On the other hand, if it is determined that a voltage drop of equal to or greater than the voltage threshold has occurred in at least one electrolytic cell 101, the voltage determination unit 201 outputs the determination result and an identification signal for identifying the electrolytic cell 101 (hereinafter, sometimes referred to as the determination result, etc.) to the current determination unit 202.

[0031] The determination result, etc. may include various information related to the determination of the next and subsequent steps, in addition to the determination result and the identification number of the electrolytic cell 101. For example, when a plurality of electrolytic cells 10 are installed in the water electrolysis apparatus 1, the determination result, etc. may include an identification signal for identifying the electrolytic cell 10 having the electrolytic cell 101 that has been determined to have experienced a voltage drop of equal to or greater than the voltage threshold.

[0032] When it is determined that a voltage drop of equal to or greater than the voltage threshold has occurred in the electrolytic cell 101, the current determination unit 202 determines whether or not a current drop of equal to or greater than a predetermined current threshold has occurred in the electrolytic cell 10, based on the amount of current change in the electrolytic cell 10 during the specified period, i.e., the period during which it is determined that the voltage drop has occurred (current determination step). When it is determined that no current drop of equal to or greater than the current threshold has occurred in the electrolytic cell 10, the current determination unit 202 outputs the determination result, etc. to the abnormality diagnosis unit 207. On the other hand, when it is determined that a current drop of equal to or greater than the current threshold has occurred in the electrolytic cell 10, the current determination unit 202 outputs the determination result, etc. to the flow rate determination unit 203.

[0033] When it is determined that a current drop of equal to or greater than the current threshold has occurred in the electrolytic cell 10, the flow rate determination unit 203 determines whether the flow rate of the circulating water circulating through the water electrolysis apparatus 1 is equal to or less than a predetermined flow rate threshold (flow rate determination step). When it is determined that the flow rate of the circulating water is equal to or less than the flow rate threshold, the flow rate determination unit 203 outputs the determination result, etc. to the conductivity determination unit 204. On the other hand, when it is determined that the flow rate of the circulating water exceeds the flow rate threshold, the flow rate determination unit 203 outputs the determination result, etc. to the hydrogen concentration determination unit 205.

[0034] When it is determined that the flow rate of the circulating water is equal to or lower than the flow rate threshold, the conductivity determination unit 204 determines whether or not the circulating water has experienced an increase in conductivity equal to or higher than a predetermined conductivity threshold based on the amount of change in the conductivity of the circulating water in a certain period after the predetermined period (conductivity determination step). In both cases where it is determined that the circulating water has not experienced an increase in conductivity equal to or higher than the conductivity threshold, and where it is determined that the circulating water has experienced an increase in conductivity equal to or higher than the conductivity threshold, the conductivity determination unit 204 outputs the determination result and the like to the abnormality diagnosis unit 207.

[0035] When it is determined that the flow rate of the circulating water exceeds the flow rate threshold, the hydrogen concentration determination unit 205 determines whether or not an increase in hydrogen concentration equal to or greater than a predetermined hydrogen concentration threshold has occurred, based on the amount of change in hydrogen concentration contained in the oxygen generated in the electrolytic cell 10 (hydrogen concentration determination step). When it is determined that an increase in hydrogen concentration equal to or greater than the hydrogen concentration threshold has occurred, the hydrogen concentration determination unit 205 outputs the determination result, etc. to the abnormality diagnosis unit 207. On the other hand, when it is determined that an increase in hydrogen concentration equal to or greater than the hydrogen concentration threshold has not occurred, the hydrogen concentration determination unit 205 outputs the determination result, etc. to the wastewater volume determination unit 206.

[0036] When it is determined that no increase in hydrogen concentration equal to or greater than the hydrogen concentration threshold has occurred, the discharge amount determination unit 206 determines whether or not an increase in the discharge amount equal to or greater than a predetermined discharge amount threshold has occurred in the discharged water from the hydrogen gas-liquid separator 11 (hydrogen concentration determination step). In both cases where it is determined that no increase in the discharge amount equal to or greater than the discharge amount threshold has occurred and where it is determined that an increase in the discharge amount equal to or greater than the discharge amount threshold has occurred, the discharge amount determination unit 206 outputs the determination result and the like to the abnormality diagnosis unit 207.

[0037] The abnormality diagnosis unit 207 diagnoses whether or not there is an abnormality in the solid polymer electrolyte membrane 102 based on the judgment result output from the judgment unit described above. For example, when the abnormality diagnosis unit 207 receives a judgment result from the voltage judgment unit 201 indicating that no voltage drop of a voltage threshold or more has occurred in the electrolytic cell 101, the abnormality diagnosis unit 207 diagnoses that there is no abnormality in the solid polymer electrolyte membrane 102. When the abnormality diagnosis unit 207 receives a judgment result from the current judgment unit 202 indicating that no current voltage drop of a current threshold or more has occurred in the electrolytic cell 10, the abnormality diagnosis unit 207 diagnoses that there is an abnormality in the solid polymer electrolyte membrane 102 of the electrolytic cell 101 identified by the identification signal. The abnormality diagnosis unit 207 outputs the diagnosis result to the device control unit 208.

[0038] The equipment control unit 208 executes a notification process to notify a monitor or the like of the diagnosis result based on the diagnosis result obtained from the abnormality diagnosis unit 207. For example, when a diagnosis result indicating that there is an abnormality in the solid polymer electrolyte membrane 102 is obtained, the equipment control unit 208 executes a notification process to notify a monitor or the like that an abnormality may have occurred in the solid polymer electrolyte membrane 102. The notification method is arbitrary, and for example, the fact that there is a possibility that an abnormality has occurred in the solid polymer electrolyte membrane 102 may be displayed on a display or the like together with the identification number of the electrolysis cell 101.

[0039] [Flow of abnormality diagnosis process] Next, the flow of the abnormality diagnosis process (abnormality diagnosis method) executed by the information processing device 2 will be described with reference to Fig. 3. Fig. 3 is a flow chart showing an example of the abnormality diagnosis process executed by the information processing device 2. After the electrolysis operation of the electrolytic cell 10 starts, the control unit 20 repeatedly executes the abnormality diagnosis process shown in Fig. 3.

[0040] First, the voltage determination unit 201 determines for each electrolytic cell 101 whether a voltage drop of equal to or greater than a predetermined voltage threshold has occurred in the electrolytic cell 101 (step S1: voltage determination step). For example, the voltage determination unit 201 reads out from the storage unit 22 history information of the detection signal output by the voltmeter 40 and the voltage threshold, and calculates the amount of voltage change for each electrolytic cell 101 during a predetermined period during electrolysis operation. Then, based on the calculated amount of voltage change and the voltage threshold, the voltage determination unit 201 determines for each electrolytic cell 101 whether a voltage drop of equal to or greater than the voltage threshold has occurred.

[0041] For example, the voltage determination unit 201 may calculate a voltage deviation for each electrolytic cell 101, which is the difference between the voltage value of one electrolytic cell 101 (its own cell voltage value) among the multiple electrolytic cells 101 and the average voltage value of the remaining electrolytic cells 101 (the average voltage value of the other cells excluding the own cell), and calculate the amount of voltage change for each electrolytic cell 101 during the specified period based on the voltage deviation.

[0042] In this case, the voltage determination unit 201 may calculate the voltage deviation (absolute value) for each electrolysis cell 101 based on, for example, the following (Equation 1). Voltage deviation = (average voltage value of other cells excluding the own cell) - (own cell voltage value) ... (Equation 1)

[0043] Furthermore, the voltage determination unit 201 may calculate the amount of voltage change (absolute value) for each electrolysis cell 101 based on, for example, the following (Equation 2). Voltage change amount = (most recent voltage deviation time average) - (past voltage deviation time average) ... (Equation 2)

[0044] This makes it possible to properly calculate minute voltage changes for each electrolytic cell 101 during electrolysis operation, and to diagnose abnormalities in the solid polymer electrolyte membrane 102 with high accuracy.

[0045] In addition, each cell voltage value when electrolysis operation was performed under the same conditions in the past may be stored in the memory unit 22, and the voltage deviation may be calculated in the above (Equation 1) using the "own cell voltage value" under the same conditions among the stored values.

[0046] In addition, the method for setting the voltage threshold is not limited. For example, the value (absolute value) calculated from the following (Equation 3) and (Equation 4) is set as the voltage threshold V th It may also be used as. R0=(V d -1.48[V]) / I d …(Formula 3) Voltage threshold V th =V d ×{1-17.2[mΩ] / (17.2[mΩ]+R0)}…(Formula 4) R0: Voltage value of electrolytic cell V d : Maximum temperature and rated current I d Voltage value of electrolytic cell at 1.48[V]: Theoretical operating voltage of the electrolytic cell 17.2 [mΩ]: Estimated resistance value of the micro-short circuit

[0047] Such a voltage threshold V thBy using this, it is possible to determine, for example, whether a micro-short circuit may have occurred in the solid polymer electrolyte membrane 102. When a micro-short circuit occurs, the voltage drop is very small, so the voltage of the electrolysis cell 101 may not drop to the theoretical voltage (theoretical electrolysis voltage). The information processing device 2 is capable of monitoring slight voltage drops in a range larger than the theoretical voltage (a range that does not fall below the theoretical voltage), so that the presence or absence of a micro-short circuit can be suitably diagnosed.

[0048] Here, when the area of ​​the electrolytic cell 101 (the dimension in the in-plane direction of the electrolytic cell 101) becomes large, it becomes difficult to detect a voltage drop in the electrolytic cell 101 due to a microshort circuit. When the area of ​​the electrolytic cell 101 is relatively small, the resistance of the cell itself becomes large, and the voltage drop due to a microshort circuit becomes large. On the other hand, when the area of ​​the electrolytic cell 101 is relatively large, the resistance of the cell itself becomes small, and the voltage drop due to a microshort circuit becomes small. For this reason, even if a microshort circuit of the same magnitude occurs, the larger the area of ​​the electrolytic cell 101, the smaller the voltage drop, and it becomes difficult to determine whether or not there is a minute voltage drop in the electrolytic cell 101.

[0049] The voltage determination unit 201 according to this embodiment calculates the amount of voltage change based on the above-mentioned voltage deviation, and therefore can calculate minute amounts of voltage change for each electrolytic cell 101 during electrolysis operation. Therefore, even if the area of ​​the electrolytic cell 101 is large, it is possible to determine the presence or absence of a minute voltage drop due to a micro-short circuit.

[0050] If it is determined that no voltage drop of equal to or greater than the voltage threshold has occurred in any of the electrolytic cells 101 (NO in step S1), the voltage determination unit 201 outputs the determination result to the abnormality diagnosis unit 207. If this determination result is obtained from the voltage determination unit 201, the abnormality diagnosis unit 207 diagnoses that no abnormality exists in the solid polymer electrolyte membrane 102 (step S8). On the other hand, if it is determined that a voltage drop of equal to or greater than the voltage threshold has occurred in at least one of the electrolytic cells 101 (YES in step S1), the voltage determination unit 201 outputs an identification signal for identifying the electrolytic cell 101 in which a voltage drop of equal to or greater than the voltage threshold has occurred, together with the determination result, to the current determination unit 202.

[0051] Next, if it is determined that a voltage drop of equal to or greater than the voltage threshold has occurred in the electrolytic cell 101, the current determination unit 202 determines whether or not a current drop of equal to or greater than a predetermined current threshold has occurred in the electrolytic bath 10 (step S2: current determination step). For example, the current determination unit 202 reads out from the memory unit 22 the history information of the detection signal output by the ammeter 41 and the current threshold, and calculates the amount of current change in the electrolytic bath 10 over the predetermined period. Then, based on the calculated amount of current change and the current threshold, the current determination unit 202 determines whether or not a current drop of equal to or greater than the current threshold has occurred in the electrolytic bath 10.

[0052] The current determination unit 202 may calculate the amount of change (absolute value) of the current in the electrolytic cell 10, for example, based on the following (Equation 5). Current change amount = (most recent current time average) - (past current time average) ... (Equation 5)

[0053] In addition, the method for setting the current threshold is not particularly limited. For example, the value (absolute value) calculated from the following (Equation 6) is set as the current threshold I th It may also be used as. Current Threshold I th =V th / R0…(Formula 6)

[0054] If it is determined that no current drop of equal to or greater than the current threshold has occurred in the electrolytic bath 10 (NO in step S2), the current determination unit 202 outputs the determination result, etc. to the abnormality diagnosis unit 207. If the determination result, etc. is obtained from the current determination unit 202, the abnormality diagnosis unit 207 diagnoses that there is an abnormality in the solid polymer electrolyte membrane 102 (step S8). On the other hand, if it is determined that a current drop of equal to or greater than the current threshold has occurred in the electrolytic bath 10 (YES in step S2), the current determination unit 202 outputs the determination result, etc. to the flow rate determination unit 203.

[0055] Here, the voltage of the electrolytic cell 101 during electrolysis operation depends on the current flowing through the electrolytic cell 10, as well as on the presence or absence of an abnormality in the solid polymer electrolyte membrane 102. For this reason, for example, if it is determined in step S1 that a voltage drop of equal to or greater than the voltage threshold has occurred in the electrolytic cell 101, it is possible that the cause of this voltage drop is not an abnormality in the solid polymer electrolyte membrane 102 but a current drop in the electrolytic cell 10. Therefore, in the abnormality diagnosis process, if a voltage drop of equal to or greater than the voltage threshold has occurred in the electrolytic cell 101 during a predetermined period during electrolysis operation, it is further determined in step S2 whether or not a current drop of equal to or greater than the current threshold has occurred in the electrolytic cell 10 during the same period. This is because, if no current drop of equal to or greater than the current threshold has occurred in the electrolytic cell 10, it is assumed that the cause of the voltage drop in the electrolytic cell 101 is likely to be an abnormality in the solid polymer electrolyte membrane 102, rather than a current drop in the electrolytic cell 10.

[0056] Note that the change in voltage of the electrolytic cells 101 during electrolysis operation depends not only on the electrolysis current but also on the degree of deterioration of the solid polymer electrolyte membrane 102 and the temperature of the electrolytic cell 10, but these degrees of deterioration and temperatures do not change suddenly. Therefore, by taking into account at least the current change in the electrolytic cell 10 as well as the voltage change in each electrolytic cell 101, the possibility of erroneous diagnosis can be reduced.

[0057] In this way, by steps S1, S2 and S8, it is possible to diagnose the occurrence of an abnormality in the solid polymer electrolyte membrane 102 based on the amount of voltage change in the electrolytic cell 101 and the amount of current change in the electrolytic cell 10 during electrolytic operation, without stopping the electrolytic operation.

[0058] Next, when it is determined that a current drop of equal to or greater than the current threshold has occurred in the electrolytic bath 10, the flow rate determination unit 203 determines whether the flow rate of the circulating water circulating through the water circulation line 13 of the water electrolysis apparatus 1 is equal to or less than a predetermined flow rate threshold (step S3: flow rate determination step). For example, the flow rate determination unit 203 reads out from the storage unit 22 the history information of the detection signal output by the circulating water flow meter 42 and the flow rate threshold, and determines whether the flow rate of the circulating water is equal to or less than the predetermined flow rate threshold.

[0059] The flow rate determination unit 203 determines whether the flow rate of the circulating water in the entire circulating system (total circulating water volume) is equal to or less than the flow rate threshold value. In this case, for example, a value calculated from the following (Equation 7) is set as the flow rate threshold value Q th It may also be used as. Flow Threshold Q th =27 / Conductivity meter measurement accuracy x margin (approximately 3 times)...(Formula 7)

[0060] If it is determined that the flow rate of the circulating water is equal to or lower than the flow rate threshold (YES in step S3), the flow rate determination unit 203 outputs the determination result, etc. to the conductivity determination unit 204. On the other hand, if it is determined that the flow rate of the circulating water exceeds the flow rate threshold (NO in step S3), the flow rate determination unit 203 outputs the determination result, etc. to the hydrogen concentration determination unit 205.

[0061] Note that the flow rate determination unit 203 may use, for example, the flow rate [L / min] of the circulating water per unit time flowing through the water circulation line 13 instead of the flow rate [L] of the circulating water in the entire circulation system to determine whether the flow rate is equal to or lower than the flow rate threshold. In this case, a conductivity meter 43 may be installed on the outlet side of the circulating water of the electrolytic cell 10, that is, in the pipe connecting the electrolytic cell 10 and the oxygen-gas-liquid separator 12. This allows the conductivity meter 43 to detect the conductivity before the circulating water is diluted by the pure water in the oxygen-gas-liquid separator 12 and the conductivity decreases, thereby improving the accuracy of the determination in the subsequent conductivity determination step.

[0062] Next, when it is determined that the flow rate of the circulating water is equal to or lower than the flow rate threshold, the conductivity determination unit 204 determines whether or not an increase in conductivity equal to or higher than a predetermined conductivity threshold has occurred in the circulating water circulating through the water circulation line 13 (step S4: conductivity determination step). For example, the conductivity determination unit 204 reads out the history information of the detection signal output by the conductivity meter 43 and the conductivity threshold from the storage unit 22, and calculates the amount of change in conductivity of the circulating water for a certain period after the predetermined period. Then, the conductivity determination unit 204 determines whether or not an increase in conductivity equal to or higher than the conductivity threshold has occurred in the electrolytic cell 10, based on the calculated amount of change in conductivity and the conductivity threshold.

[0063] Here, if a micro-short circuit occurs due to penetration of the conductive fiber or the like, heat is generated at the part where the micro-short circuit has occurred, causing internal components such as the solid polymer electrolyte membrane 102 to dissolve into the circulating water, increasing the conductivity of the circulating water. Therefore, an abnormality in the solid polymer electrolyte membrane 102 can be diagnosed based on the amount of change in the conductivity of the circulating water. However, when the flow rate of the circulating water exceeds the flow rate threshold, that is, when the flow rate of the circulating water is relatively high, it becomes difficult to accurately detect the conductivity of the circulating water using the conductivity meter 43. This is because the higher the flow rate of the circulating water, the more difficult it is for the conductivity of the circulating water to increase. Therefore, by performing the determination of the increase in conductivity (step S4) only when the flow rate of the circulating water is equal to or lower than the flow rate threshold, an abnormality in the solid polymer electrolyte membrane 102 can be diagnosed with high accuracy.

[0064] The conductivity determination unit 204 may calculate the amount of change (absolute value) in the conductivity of the electrolytic cell 10 based on, for example, the following (Equation 8). Conductivity change amount = (most recent conductivity time average) - (past conductivity time average) ... (Equation 8)

[0065] In addition, the method for setting the conductivity threshold value is not particularly limited. For example, the value calculated from the following (Equation 9) is used as the conductivity threshold value C th It may also be used as. Conductivity threshold C th =27 / circulating water flow rate [L]…(Formula 9)

[0066] When it is determined that the circulating water has experienced an increase in conductivity equal to or greater than the conductivity threshold (YES in step S4), the conductivity determination unit 204 outputs the determination result, etc. to the abnormality diagnosis unit 207. When the abnormality diagnosis unit 207 receives this determination result, etc. from the conductivity determination unit 204, it diagnoses that there is an abnormality in the solid polymer electrolyte membrane 102 (step S7). When it is determined that there is not an increase in conductivity equal to or greater than the conductivity threshold (NO in step S4), the conductivity determination unit 204 outputs the determination result, etc. to the abnormality diagnosis unit 207. When the abnormality diagnosis unit 207 receives this determination result, etc. from the conductivity determination unit 204, it diagnoses that there is no abnormality in the solid polymer electrolyte membrane 102 (step S8).

[0067] Next, when it is determined that the flow rate of the circulating water exceeds the flow rate threshold, the hydrogen concentration determination unit 205 determines whether or not an increase in hydrogen concentration equal to or greater than a predetermined hydrogen concentration threshold has occurred in the oxygen generated in the electrolytic cell 10 (step S5: hydrogen concentration determination step). For example, the hydrogen concentration determination unit 205 reads out from the memory unit 22 the history information of the detection signal output by the hydrogen concentration meter 44 and the hydrogen concentration threshold, and calculates the amount of change in hydrogen concentration over the certain period of time. Then, based on the calculated amount of change in hydrogen concentration and the hydrogen concentration threshold, the hydrogen concentration determination unit 205 determines whether or not an increase in hydrogen concentration equal to or greater than the hydrogen concentration threshold has occurred.

[0068] For example, if a pinhole occurs in the solid polymer electrolyte membrane 102, gas will leak through the pinhole, causing an increase in the hydrogen concentration in the oxygen generated in the electrolytic cell 10. Therefore, it is possible to diagnose the presence of an abnormality in the solid polymer electrolyte membrane 102 based on the amount of change in the hydrogen concentration in the oxygen.

[0069] The hydrogen concentration determination unit 205 may calculate the amount of change in the concentration of hydrogen contained in oxygen based on, for example, the following (Equation 10). Hydrogen concentration change = (most recent hydrogen concentration in oxygen) - (previous hydrogen concentration in oxygen) ... (Equation 10)

[0070] In addition, the method for setting the hydrogen concentration threshold is not particularly limited. For example, the hydrogen concentration threshold H thIt may also be used as. Hydrogen concentration threshold H th = 900 [ppm] / amount of hydrogen generated [Nm 3 / h]…(Formula 11)

[0071] If it is determined that a hydrogen concentration increase equal to or greater than the hydrogen concentration threshold has occurred (YES in step S5), hydrogen concentration determination unit 205 outputs the determination result, etc. to abnormality diagnosis unit 207. If this determination result, etc. is obtained from hydrogen concentration determination unit 205, abnormality diagnosis unit 207 diagnoses that an abnormality exists in solid polymer electrolyte membrane 102 (step S7). On the other hand, if it is determined that a hydrogen concentration increase equal to or greater than the hydrogen concentration threshold has not occurred (NO in step S5), hydrogen concentration determination unit 205 outputs the determination result, etc. to wastewater amount determination unit 206.

[0072] Next, if it is determined that no increase in hydrogen concentration equal to or greater than the hydrogen concentration threshold has occurred, the discharged water amount determination unit 206 determines whether or not an increase in the discharged water amount equal to or greater than a predetermined discharged water amount threshold has occurred in the discharged water from the hydrogen gas-liquid separator 11 (step 6: hydrogen concentration determination step). For example, the discharged water amount determination unit 206 reads out from the memory unit 22 the history information of the detection signal output by the discharged water flow meter 45 and the discharged water amount threshold, and calculates the amount of change in the discharged water during the certain period. Then, the discharged water amount determination unit 206 determines whether or not an increase in the discharged water amount equal to or greater than the discharged water amount threshold has occurred based on the calculated amount of change in the discharged water and the discharged water amount threshold.

[0073] For example, if a pinhole occurs in the solid polymer electrolyte membrane 102, water will leak through the pinhole, causing an increase in the discharged water flow rate from the hydrogen-gas-liquid separator 11. Therefore, an abnormality in the solid polymer electrolyte membrane 102 can be diagnosed based on the change in the discharged water flow rate from the hydrogen-gas-liquid separator 11.

[0074] The wastewater amount determination unit 206 may calculate the amount of change (absolute value) of the wastewater contained in the oxygen generated in the electrolytic cell 10 based on, for example, the following (Equation 12). Discharge change amount = (Latest accumulated discharge amount) - (Past accumulated discharge amount) ... (Formula 12)

[0075] When it is determined that an increase in the discharge amount equal to or greater than the discharge amount threshold has occurred (YES in step S7), the discharge amount determination unit 206 outputs the determination result, etc. to the abnormality diagnosis unit 207. When this determination result, etc. is obtained from the discharge amount determination unit 206, the abnormality diagnosis unit 207 diagnoses that there is an abnormality in the solid polymer electrolyte membrane 102 (step S7). On the other hand, when it is determined that an increase in the discharge amount equal to or greater than the discharge amount threshold has not occurred (NO in step S7), the discharge amount determination unit 206 outputs the determination result to the abnormality diagnosis unit 207. When this determination result, etc. is obtained from the discharge amount determination unit 206, the abnormality diagnosis unit 207 diagnoses that there is no abnormality in the solid polymer electrolyte membrane 102 (step S8).

[0076] There is no particular restriction on the order of steps S2 to S7, that is, after step S1 is executed, any of steps S2 to S7 may be executed.

[0077] [Effects of the water electrolysis system 100] Thus, the water electrolysis system 100 according to the present embodiment includes an information processing device 2 that diagnoses an abnormality in the water electrolysis apparatus 1 that includes an electrolytic cell 10 in which a plurality of electrolytic cells 101, each including a solid polymer electrolyte membrane 102, are connected in series. The information processing device 2 includes a determination unit 200 that includes a voltage determination unit 201 that determines, for each electrolytic cell 101, whether a voltage drop of equal to or greater than a predetermined voltage threshold has occurred in the electrolytic cell 101 based on the amount of voltage change in each electrolytic cell 101 during a predetermined period during electrolysis operation, and an abnormality diagnosis unit 207 that diagnoses an abnormality in the solid polymer electrolyte membrane 102 based on the determination result of the determination unit 200.

[0078] The information processing device 2 diagnoses an abnormality in the solid polymer electrolyte membrane 102 for each electrolysis cell 101 without stopping the electrolysis operation. Therefore, according to the present embodiment, an abnormality in the solid polymer electrolyte membrane 102 can be diagnosed without reducing the operating rate of the water electrolysis apparatus 1.

[0079] Furthermore, the information processing device 2 can execute the above-mentioned abnormality diagnosis process by applying output signals from various sensors provided in general water electrolysis equipment, and therefore the information processing device 2 can be suitably applied to existing water electrolysis equipment.

[0080] [Modifications] The execution entity of each process described in the above embodiment may be any entity and is not limited to the above examples. For example, a configuration may be adopted in which a control device separate from the information processing device 2 controls the water electrolysis device 1. In this case, the information processing device 2 may execute an abnormality diagnosis process to determine whether or not an abnormality has occurred in the solid polymer electrolyte membrane 102, notify the control device of the diagnosis result, and cause the control device to execute control for an abnormality notification.

[0081] The information processing device 2 may be installed anywhere, for example, in a monitoring room for monitoring the water electrolysis apparatus 1, or in another location. For example, the information processing device 2 may be installed on a cloud, in which case the information processing device 2 may be accessed by any terminal device to check the diagnosis results. In this case, a single information processing device 2 may also be used to monitor multiple water electrolysis apparatuses 1.

[0082] [Software implementation example] The control blocks of the information processing device 2 (particularly the voltage determination unit 201, the current determination unit 202, the flow rate determination unit 203, the conductivity determination unit 204, the hydrogen concentration determination unit 205, the wastewater amount determination unit 206, and the abnormality diagnosis unit 207) may be realized by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like, or may be realized by software.

[0083] In the latter case, the information processing device 2 includes a computer that executes instructions of an abnormality diagnosis program, which is software that realizes each function. The computer includes, for example, one or more processors, and a computer-readable recording medium that stores the program. The object of the present invention is achieved by the processor reading the program from the recording medium and executing it in the computer. The processor may be, for example, a CPU (Central Processing Unit). The recording medium may be a "non-transient tangible medium," such as a ROM (Read Only Memory), as well as a tape, a disk, a card, a semiconductor memory, a programmable logic circuit, or the like. The computer may further include a RAM (Random Access Memory) that expands the program. The program may be supplied to the computer via any transmission medium (such as a communication network or a broadcast wave) that can transmit the program. Note that one aspect of the present invention may also be realized in the form of a data signal embedded in a carrier wave, in which the program is embodied by electronic transmission.

[0084] 〔summary〕 The abnormality diagnosis device according to a first aspect of the present invention is an abnormality diagnosis device for a water electrolysis apparatus having an electrolytic cell in which a plurality of electrolytic cells, each including a solid polymer electrolyte membrane, are connected in series, and comprises: a judgment unit including a voltage judgment unit that judges for each electrolytic cell whether a voltage drop of a predetermined threshold or more has occurred in the electrolytic cell based on the amount of voltage change in each of the electrolytic cells during a predetermined period of time during electrolysis operation; and an abnormality diagnosis unit that diagnoses an abnormality in the solid polymer electrolyte membrane based on the judgment result of the judgment unit.

[0085] In the above configuration, the solid polymer electrolyte membrane is diagnosed for each electrolysis cell without stopping the electrolysis operation, and therefore, the solid polymer electrolyte membrane can be diagnosed for an abnormality without reducing the operating rate of the water electrolysis device.

[0086] In the abnormality diagnosis device according to aspect 2 of the present invention, in the above aspect 1, the judgment unit may further include a current judgment unit that, when it is determined that the voltage drop has occurred, judges whether a current drop of equal to or greater than a predetermined current threshold has occurred in the electrolytic bath based on an amount of current change in the electrolytic bath during the specified period, and the abnormality diagnosis unit may diagnose that there is an abnormality in the solid polymer electrolyte membrane when it is determined that the current drop has not occurred.

[0087] The voltage of the electrolytic cell during electrolysis operation depends on the presence or absence of an abnormality in the solid polymer electrolyte membrane as well as the current flowing through the electrolytic cell. Therefore, for example, if a voltage drop of more than a voltage threshold occurs in the electrolytic cell, the cause of this voltage drop may be a current drop in the electrolytic cell rather than an abnormality in the solid polymer electrolyte membrane.

[0088] Therefore, in the above configuration, when a voltage drop of equal to or greater than the voltage threshold occurs in the electrolytic cell during a predetermined period of electrolysis operation, it is further determined whether or not a current drop of equal to or greater than the current threshold occurs in the electrolytic cell during the same period. This is because, when a current drop of equal to or greater than the current threshold does not occur in the electrolytic cell, it is presumed that the cause of the voltage drop in the electrolytic cell is likely to be an abnormality in the solid polymer electrolyte membrane, rather than a current drop in the electrolytic cell.

[0089] In this manner, the above-described configuration diagnoses an abnormality in the solid polymer electrolyte membrane for each electrolytic cell based on the amount of change in the voltage of the electrolytic cell and the amount of change in the current of the electrolytic cell during electrolysis operation without stopping the electrolysis operation. Therefore, the above-described configuration makes it possible to diagnose an abnormality in the solid polymer electrolyte membrane with high accuracy without reducing the operating rate of the water electrolysis device.

[0090] In the abnormality diagnosis device according to aspect 3 of the present invention, in accordance with aspect 1, the determination unit may further include a flow rate determination unit that, when it is determined that the voltage drop has occurred, determines whether or not a flow rate of circulating water circulating through the water electrolysis device is equal to or lower than a predetermined flow rate threshold.

[0091] When the flow rate of the circulating water exceeds the flow rate threshold, that is, when the flow rate of the circulating water is relatively high, it becomes difficult to accurately detect, for example, a change in the conductivity of the circulating water using a sensor, etc. Therefore, according to the above configuration, it becomes possible to perform processing such as determining whether the conductivity has increased only when the flow rate of the circulating water is equal to or lower than the flow rate threshold, and it is possible to diagnose an abnormality in the solid polymer electrolyte membrane with high accuracy.

[0092] In the abnormality diagnosis device according to aspect 4 of the present invention, in accordance with aspect 1, the determination unit may further include a conductivity determination unit that, when it is determined that the voltage drop has occurred, determines whether or not an increase in conductivity of the circulating water that is equal to or greater than a predetermined conductivity threshold has occurred based on an amount of change in conductivity of the circulating water circulating through the water electrolysis device, and the abnormality diagnosis unit may diagnose an abnormality in the solid polymer electrolyte membrane when it is determined that the conductivity increase has occurred.

[0093] When a micro-short circuit occurs due to the penetration of conductive fibers, the heat generated at the part where the micro-short circuit occurs causes internal components such as the solid polymer electrolyte membrane to dissolve into the circulating water, increasing the conductivity of the circulating water. Therefore, according to the above configuration, it is possible to diagnose an abnormality in the solid polymer electrolyte membrane based on the amount of change in the conductivity of the circulating water.

[0094] In the abnormality diagnosis device according to aspect 5 of the present invention, in the above aspect 1, the judgment unit may further include a concentration judgment unit that, when it is determined that the voltage drop has occurred, judges whether or not an increase in hydrogen concentration has occurred that is equal to or greater than a predetermined hydrogen concentration threshold based on an amount of change in hydrogen concentration contained in oxygen generated in the electrolytic cell, and the abnormality diagnosis unit may diagnose that there is an abnormality in the solid polymer electrolyte membrane when it is determined that the hydrogen concentration increase has occurred.

[0095] For example, if a pinhole occurs in the solid polymer electrolyte membrane, water and gas will leak through the pinhole, causing an increase in the hydrogen concentration in the oxygen generated in the electrolytic cell. Therefore, according to the above configuration, it is possible to diagnose an abnormality in the solid polymer electrolyte membrane based on the amount of change in the hydrogen concentration in the oxygen.

[0096] In an abnormality diagnosis device according to aspect 6 of the present invention, in any one of aspects 1 to 5, the voltage judgment unit may calculate a voltage deviation for each electrolytic cell, which is the difference between a voltage value of one of the plurality of electrolytic cells and an average voltage value of the remaining electrolytic cells, and calculate the amount of voltage change for each electrolytic cell during the specified period based on the voltage deviation.

[0097] According to the above configuration, minute voltage changes for each electrolytic cell during electrolysis operation can be appropriately calculated, and abnormalities in the solid polymer electrolyte membrane can be diagnosed with high accuracy.

[0098] An abnormality diagnosis program according to aspect 7 of the present invention is an abnormality diagnosis program for causing a computer to function as an abnormality diagnosis device described in any one of aspects 1 to 6, and is a program for causing a computer to function as the judgment unit and the abnormality diagnosis unit.

[0099] According to the above configuration, the computer can function as the determination unit and the abnormality diagnosing unit of the abnormality diagnosing device.

[0100] An abnormality diagnosis method according to an eighth aspect of the present invention is a method for diagnosing an abnormality in a water electrolysis apparatus including an electrolytic cell in which a plurality of electrolytic cells, each including a solid polymer electrolyte membrane, are connected in series, and includes a determination step including a voltage determination step of determining for each electrolytic cell whether a voltage drop of equal to or greater than a predetermined voltage threshold has occurred in the electrolytic cell based on an amount of voltage change in each of the electrolytic cells over a predetermined period during electrolysis operation, and an abnormality diagnosis step of diagnosing an abnormality in the solid polymer electrolyte membrane based on a determination result of the determination step.

[0101] In the method, an abnormality in the solid polymer electrolyte membrane is diagnosed based on the amount of voltage change in the electrolytic cell during electrolysis operation without stopping the electrolysis operation, and therefore, the method makes it possible to diagnose an abnormality in the solid polymer electrolyte membrane without reducing the operating rate of the water electrolysis device.

[0102] A ninth aspect of the present invention provides an abnormality diagnosis device for a water electrolysis apparatus including an electrolytic cell in which a plurality of electrolytic cells, each including a solid polymer electrolyte membrane, are connected in series, the abnormality diagnosis device including a voltage determination unit that determines for each electrolytic cell whether a voltage drop equal to or greater than a predetermined voltage threshold has occurred in the electrolytic cell based on an amount of voltage change in each of the electrolytic cells during a predetermined period of electrolysis operation, a current determination unit that, when it is determined that the voltage drop has occurred, determines whether a current drop equal to or greater than a predetermined current threshold has occurred in the electrolytic cell based on an amount of current change in the electrolytic cell during the predetermined period, a flow rate determination unit that, when it is determined that the current drop has occurred, determines whether a flow rate of circulating water circulating through the water electrolysis apparatus is equal to or less than a predetermined flow rate threshold, and a flow rate determination unit that, when it is determined that the current drop has occurred, determines whether a flow rate of circulating water circulating through the water electrolysis apparatus is equal to or less than a predetermined flow rate threshold. the flow rate exceeds the flow rate threshold, based on an amount of change in hydrogen concentration contained in oxygen generated in the electrolytic cell; and an abnormality diagnosis unit that diagnoses an abnormality in the solid polymer electrolyte membrane based on a determination result from the determination unit, wherein the abnormality diagnosis unit diagnoses an abnormality in the solid polymer electrolyte membrane when it is determined that the conductivity increase has occurred, and diagnoses an abnormality in the solid polymer electrolyte membrane when it is determined that the hydrogen concentration increase has occurred.

[0103] In the above configuration, the determination unit executes the determination processes in the order of voltage determination → current determination → flow rate determination → conductivity determination, or in the order of voltage determination → current determination → flow rate determination → concentration determination. By executing the determination processes in these orders, unnecessary calculation processes in the determination unit can be eliminated, and each determination process can be executed most efficiently.

[0104] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in the embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0105] 1: Water electrolysis device 2: Information processing device (abnormality diagnosis device) 10: Electrolytic cell 101: Electrolytic cell 102: Solid polymer electrolyte membrane 200: Judgment section 201: Voltage judgment unit 202: Current judgment section 203:Flow rate determination section 204: Conductivity determination section 205: Hydrogen concentration determination unit (concentration determination unit) 207: Abnormality diagnosis section S1: Voltage judgment step S7: Abnormality diagnosis step

Claims

1. An abnormality diagnosis device for a water electrolysis apparatus including an electrolytic cell in which a plurality of electrolytic cells, each including a solid polymer electrolyte membrane, are connected in series, a determination unit including a voltage determination unit that determines, for each electrolytic cell, whether a voltage drop of a predetermined threshold value or more has occurred in the electrolytic cell based on an amount of voltage change in each electrolytic cell during a predetermined period during electrolysis operation; an abnormality diagnosis unit that diagnoses an abnormality in the solid polymer electrolyte membrane based on a determination result of the determination unit; An abnormality diagnosis device comprising:

2. the determination unit further includes a current determination unit that, when it is determined that the voltage drop has occurred, determines whether or not a current drop of equal to or greater than a predetermined current threshold has occurred in the electrolytic bath based on an amount of change in current in the electrolytic bath during the specified period; 2 . The abnormality diagnostic device according to claim 1 , wherein the abnormality diagnostic unit diagnoses that an abnormality exists in the solid polymer electrolyte membrane when it is determined that the current decrease has not occurred.

3. 2. The abnormality diagnosis device according to claim 1, wherein the determination unit further includes a flow rate determination unit that, when it is determined that the voltage drop has occurred, determines whether a flow rate of the circulating water circulating through the water electrolysis device is equal to or lower than a predetermined flow rate threshold.

4. the determination unit further includes a conductivity determination unit that, when it is determined that the voltage drop has occurred, determines whether or not an increase in conductivity of the circulating water that is equal to or greater than a predetermined conductivity threshold has occurred, based on an amount of change in conductivity of the circulating water circulating through the water electrolysis apparatus; and 2. The abnormality diagnostic device according to claim 1, wherein the abnormality diagnostic unit diagnoses that an abnormality exists in the solid polymer electrolyte membrane when it is determined that the electrical conductivity has increased.

5. the determination unit further includes a concentration determination unit that, when it is determined that the voltage drop has occurred, determines whether or not a hydrogen concentration increase equal to or greater than a predetermined hydrogen concentration threshold has occurred based on an amount of change in hydrogen concentration contained in the oxygen generated in the electrolytic cell; 2. The abnormality diagnostic device according to claim 1, wherein the abnormality diagnostic unit diagnoses that an abnormality exists in the solid polymer electrolyte membrane when it is determined that the hydrogen concentration increase has occurred.

6. 6. The abnormality diagnosis device according to claim 1, wherein the voltage determination unit calculates a voltage deviation for each electrolytic cell, the voltage deviation being the difference between a voltage value of one of the electrolytic cells and an average voltage value of the remaining electrolytic cells, and calculates the amount of voltage change for each electrolytic cell in the specified period based on the voltage deviation.

7. 2. An abnormality diagnosis program for causing a computer to function as the abnormality diagnosis device according to claim 1, the abnormality diagnosis program causing a computer to function as the determination unit and the abnormality diagnosis unit.

8. A method for diagnosing an abnormality in a water electrolysis apparatus including an electrolytic cell in which a plurality of electrolytic cells, each including a solid polymer electrolyte membrane, are connected in series, comprising: a determination step including a voltage determination step of determining, for each electrolytic cell, whether or not a voltage drop of a predetermined voltage threshold or more has occurred in the electrolytic cell based on an amount of voltage change in each electrolytic cell during a predetermined period during electrolysis operation; an abnormality diagnosis step of diagnosing an abnormality in the solid polymer electrolyte membrane based on a determination result of the determination step; The abnormality diagnosis method includes the steps of:

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