Condition diagnosis system, condition diagnosis method, and electrolysis system

Abstract

To accurately diagnose or predict the condition of an electrolytic device.SOLUTION: A condition diagnosis system diagnosing the condition of an electrolytic device comprises an impedance measurement device outputting data indicating the measurement result of a complex impedance of the electrolytic device, a first memory unit holding data of at least one piece of prior information including data indicating a correspondence relationship between condition information of the electrolytic device and the diagnosis result of the condition of the electrolytic device, a first processing unit analyzing the data indicating the measurement result of the complex impedance, determining the validity of the analysis result, and outputting data indicating the analysis result in which it is determined that data at least in a part of a frequency domain of the measurement result is valid, a second processing unit outputting data indicating the condition information based at least on one piece of data out of first data including the data indicating the analysis result, a second memory unit holding at least one piece of second data including the data indicating condition information, and a third processing unit outputting data indicating the diagnosis result of the condition of the electrolytic device based on a plurality of pieces of data including the data of the prior information and the second data.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD Embodiments of the present invention relate to a condition diagnostic system, a condition diagnostic method, and an electrolysis system. [Background technology]

[0002] In recent years, from the perspectives of both energy and environmental issues, there has been a demand not only for converting renewable energy such as solar power generation into electrical energy for use, but also for converting it into a form that can be stored and transported. In response to this demand, research and development is underway on artificial photosynthesis technology, which uses sunlight to produce chemical substances, similar to photosynthesis by plants. This technology has the potential to store renewable energy as storable fuel, and is also expected to create value by producing chemical substances that can be used as industrial raw materials.

[0003] Known electrolytic devices (electrochemical reaction devices) that generate chemical substances using renewable energy sources such as solar power include carbon dioxide electrolysis devices, which have a cathode that reduces carbon dioxide (CO2) generated from power plants and waste disposal plants, and an anode that oxidizes water (HO). The cathode reduces carbon dioxide to produce carbon compounds such as carbon monoxide (CO). When implementing such electrolytic devices in a cell configuration (also called an electrolysis cell), it is considered effective to implement them in a configuration similar to a fuel cell, such as a polymer electric fuel cell (PEFC). Direct supply of carbon dioxide to the catalyst layer of the cathode allows the carbon dioxide reduction reaction to proceed quickly. Furthermore, stacking electrolysis cells to form a cell stack allows the reduction reaction to proceed efficiently in a small space. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Hugh Warkentin. et. al, “Early Warning for the Electrolyzer: Monitoring CO2 Reduction via In-Line Electrochemical Impedance Spectroscopy”, Chemistry-Sustainability-Energy-Materials 2023, e202300657 Summary of the Invention [Problem to be solved by the invention]

[0005] The problem to be solved by the present invention is to diagnose or predict the state of an electrolysis device with high accuracy. [Means for solving the problem]

[0006] A condition diagnostic system according to an embodiment is a condition diagnostic system for diagnosing the condition of an electrolysis device. The electrolysis device includes an electrolysis cell. The electrolysis cell includes an anode, a cathode, and a diaphragm separating the anode and the cathode. The condition diagnosis system includes an impedance measuring device that measures the complex impedance of the electrolytic device after operation of the electrolytic device starts and outputs data indicating the measurement results of the complex impedance; a first memory unit that holds at least one piece of preliminary information data including data indicating a correspondence between state information of the electrolytic device and a diagnosis result of the state of the electrolytic device, the data being obtained before operation of the electrolytic device starts; a first processing unit that analyzes the data indicating the measurement results of the complex impedance, determines the validity of the analysis result, and outputs data indicating the analysis result in which data in at least a part of the frequency domain of the measurement result is determined to be valid; a second processing unit that outputs data indicating the state information based on at least one piece of first data including data indicating the analysis result; a second memory unit that holds at least one piece of second data including data indicating the state information; and a third processing unit that diagnoses the state of the electrolytic device based on a plurality of data including the at least one piece of preliminary information data from the first memory unit and the at least one piece of second data from the second memory unit, and outputs data indicating the diagnosis result of the state. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a schematic diagram illustrating an example of the configuration of a condition diagnosis system and an electrolysis system according to a first embodiment. FIG. [Figure 2] FIG. 1 is a schematic diagram showing a first configuration example of an electrolysis device 10. [Figure 3] FIG. 2 is a schematic diagram showing a second configuration example of the electrolysis device 10. [Figure 4] 10 is a flowchart showing an example of an analysis process performed by a processing unit 31. [Figure 5] FIG. 2 is a diagram showing an example of the complex impedance measurement results of the electrolysis device 10. [Figure 6] FIG. 1 is a schematic diagram showing a graph of the results of the Lin-KK Test. [Figure 7] This is an example of the results when a spectrum in the frequency domain (1000 Hz or less) where the residual is within ±5% is extracted and subjected to DRT analysis. [Figure 8] FIG. 10 is a schematic diagram showing an example of the results when a spectrum in a frequency domain (500 Hz or less) in which the residual is within ±3% is extracted and analyzed. [Figure 9] FIG. 10 is a diagram showing another example of the complex impedance measurement results of the electrolysis device 10. [Figure 10] FIG. 4 is a schematic diagram showing an example of the configuration of a condition diagnosis system and an electrolysis system according to a second embodiment. [Figure 11] FIG. 10 is a schematic diagram showing a configuration example of a condition diagnosis system and an electrolysis system according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, electrolysis devices according to embodiments will be described with reference to the drawings. In each of the following embodiments, substantially identical components are denoted by the same reference numerals, and some of their descriptions may be omitted. The drawings are schematic, and the relationship between thickness and planar dimensions, the thickness ratio of each component, etc. may differ from the actual ones.

[0009] In this specification, "connect" includes not only direct connection but also indirect connection unless otherwise specified. Furthermore, in this specification, "connect" includes not only physical connection but also electrical connection unless otherwise specified.

[0010] (First embodiment) Fig. 1 is a schematic diagram showing an example configuration of a condition diagnosis system and an electrolysis system according to the first embodiment. Fig. 1 shows an example configuration of an electrolysis system 1. The electrolysis system 1 includes an electrolysis device 10, a measurement unit 23, an impedance measurement device 21, an ammeter 22, a processing unit 31, a processing unit 32, a processing unit 33, a processing unit 34, a processing unit 35, a memory unit 41, and a memory unit 42. The components of the electrolysis system 1 excluding the electrolysis device 10 can form a condition diagnosis system for the electrolysis device 10. Examples of the condition diagnosis system include a degradation diagnosis system for the electrolysis device 10.

[0011] FIG. 2 is a schematic diagram showing a first configuration example of the electrolysis device 10. The electrolysis device 10 has an electrolysis cell 100. The electrolysis cell 100 has a cathode 11, an anode 12, a diaphragm (separator) 13, a cathode channel plate 14 having a cathode channel 140, and an anode channel plate 15 having an anode channel 150. The cathode 11, the anode 12, and the diaphragm 13 may be stacked to form a membrane electrode assembly MEA. The membrane electrode assembly MEA may be supported by a support plate 130. The support plate 130 is preferably formed using, for example, an insulating material.

[0012] FIG. 3 is a schematic diagram illustrating a second configuration example of the electrolysis device 10. As shown in FIG. 3, the electrolysis device 10 may include multiple electrolysis cells 100. For example, the multiple electrolysis cells 100 are stacked with an insulating layer 18 sandwiched between them to form an electrolysis cell structure 101 such as a cell stack. The stacked electrolysis cells 100 may be sandwiched between a pair of support plates and further fastened together with bolts or the like. Although FIG. 3 shows two electrolysis cells 100, the number of electrolysis cells 100 may be two or more and is not limited to the number shown in FIG. 3.

[0013] The cathode 11 is, for example, an electrode (reduction electrode) for causing a reduction reaction of at least one reduction target (substance to be reduced) and producing at least one reduction product. The cathode 11 is in contact with the diaphragm 13. Examples of the at least one reduction target include carbon dioxide, nitrogen, hydrogen, oxygen, reduction products, etc. Examples of the at least one reduction product include carbon compounds, ammonia, etc. Examples of carbon compounds include carbon monoxide (CO), methane (CH), ethane (C2H6), etc. The reduction reaction at the cathode 11 may include a side reaction of causing a reduction reaction of water to produce hydrogen (H2). Furthermore, the reduction reaction at the cathode 11 may include a side reaction of causing a reduction reaction of oxygen to produce water (H2O) in addition to the reduction reaction of carbon dioxide.

[0014] The cathode 11 is supplied with a cathode fluid from the cathode flow channel 140, and with an anode fluid and ions from the diaphragm 13. The cathode fluid contains a gas to be reduced. The cathode 11 may have a gas diffusion layer and a cathode catalyst layer provided on the gas diffusion layer. The cathode 11 may further have a porous layer denser than the gas diffusion layer between the gas diffusion layer and the cathode catalyst layer. The gas diffusion layer is disposed on the cathode flow channel 140 side, and the cathode catalyst layer is disposed on the diaphragm 13 side. The cathode catalyst layer may be embedded in the gas diffusion layer. The cathode catalyst layer preferably contains catalyst nanoparticles or catalyst nanostructures. The gas diffusion layer is made of, for example, carbon paper or carbon cloth, and may be subjected to a water-repellent treatment. The porous layer is made of a porous material with a smaller pore size than the carbon paper or carbon cloth.

[0015] By applying an appropriate water-repellent treatment to the gas diffusion layer, carbon dioxide gas reaches the cathode catalyst layer mainly through gas diffusion. The reduction reaction of carbon dioxide and the resulting carbon compounds occurs near the boundary between the gas diffusion layer and the cathode catalyst layer, or near the cathode catalyst layer that has penetrated into the gas diffusion layer.

[0016] The cathode catalyst layer preferably contains a catalytic material (cathode catalyst material) capable of reducing the overvoltage of the reduction reaction. Examples of such materials include metals such as gold (Au), silver (Ag), copper (Cu), platinum (Pt), palladium (Pd), nickel (Ni), cobalt (Co), iron (Fe), manganese (Mn), titanium (Ti), cadmium (Cd), zinc (Zn), indium (In), gallium (Ga), lead (Pb), and tin (Sn); metal materials such as alloys and intermetallic compounds containing at least one of these metals; carbon materials such as carbon (C), graphene, carbon nanotubes (CNTs), fullerenes, and ketjen black; and metal complexes such as Ru complexes and Re complexes. The cathode catalyst layer can be in various shapes, such as a plate, mesh, wire, particle, porous, thin film, or island shape.

[0017] The cathode catalyst material constituting the cathode catalyst layer preferably comprises nanoparticles of the above-mentioned metal material, nanostructures of the metal material, nanowires of the metal material, or a composite in which nanoparticles of the above-mentioned metal material are supported on a carbon material such as carbon particles, carbon nanotubes, graphene, etc. By using catalyst nanoparticles, catalyst nanostructures, catalyst nanowires, catalyst nanosupport structures, etc. as the cathode catalyst material, the reaction efficiency of the carbon dioxide reduction reaction in the cathode 11 can be increased.

[0018] The anode 12 is, for example, an electrode (oxidation electrode) for causing an oxidation reaction of at least one oxidation target (substance to be oxidized) and generating at least one oxidation product. The at least one oxidation target includes, for example, water. Examples of the at least one oxidation product include oxygen, hydrogen ions, and the like. The oxidation reaction at the anode 12 oxidizes, for example, water (HO) in the anode solution contained in the anode fluid to generate oxygen (O) and hydrogen ions (H + ) or hydroxide ions (OH - The anode 12 is disposed between the diaphragm 13 and the anode flow channel 150 and is in contact with them.

[0019] The anode 12 preferably contains a catalytic material (anode catalytic material) capable of reducing the overvoltage of the oxidation reaction. Examples of such catalytic materials include metals such as platinum (Pt), palladium (Pd), and nickel (Ni), alloys and intermetallic compounds containing these metals, binary metal oxides such as manganese oxide (Mn-O), iridium oxide (Ir-O), nickel oxide (Ni-O), cobalt oxide (Co-O), iron oxide (Fe-O), tin oxide (Sn-O), indium oxide (In-O), ruthenium oxide (Ru-O), lithium oxide (Li-O), and lanthanum oxide (La-O), ternary metal oxides such as Ni-Co-O, Ni-Fe-O, La-Co-O, Ni-La-O, and Sr-Fe-O, quaternary metal oxides such as Pb-Ru-Ir-O and La-Sr-Co-O, and metal complexes such as Ru complexes and Fe complexes.

[0020] The anode 12 includes a substrate having a porous structure, such as a mesh material, punched material, porous material, or sintered metal fiber compact, that allows the transfer of liquid or ions between the diaphragm 13 and the anode flow path 150. The substrate may be made of a metal material such as titanium (Ti), nickel (Ni), or iron (Fe), or an alloy containing at least one of these metals (e.g., SUS), or may be made of the above-mentioned anode catalyst material. When an oxide is used as the anode catalyst material, it is preferable to form a catalyst layer by adhering or laminating the anode catalyst material to the surface of a substrate made of the above-mentioned metal material. The anode catalyst material preferably contains nanoparticles, nanostructures, nanowires, or the like to enhance the oxidation reaction. A nanostructure is a structure in which nanoscale irregularities are formed on the surface of a catalyst material. Furthermore, the anode 12 does not necessarily need to be provided with an oxidation catalyst. An oxidation catalyst layer provided elsewhere than the anode 12 may be electrically connected to the anode 12.

[0021] The diaphragm 13 is provided between the cathode 11 and the anode 12. The diaphragm 13 is arranged to separate the cathode 11 and the anode 12. The diaphragm 13 includes an ion exchange membrane that allows ions to move between the cathode 11 and the anode 12 and is capable of separating the cathode 11 and the anode 12. Examples of the ion exchange membrane include cation exchange membranes such as Nafion and Flemion, and anion exchange membranes such as Neosepta, Selemion, and Sustenion. An alkaline solution is used as the electrolyte, and the electrolyte is mainly OH. - When the movement of ions is considered, the diaphragm 13 is preferably made of an anion exchange membrane. The ion exchange membrane may also be made of a membrane with a hydrocarbon skeleton or a membrane containing amine groups. However, other materials than ion exchange membranes, such as salt bridges, glass filters, porous polymer membranes, and porous insulating materials, may also be used for the diaphragm 13, as long as they allow ions to move between the cathode 11 and the anode 12. However, if gas flows between the cathode 11 and the anode 12, a circulation reaction due to reoxidation of the reduction product may occur. Therefore, it is preferable to minimize the gas exchange between the cathode 11 and the anode 12. Therefore, care must be taken when using a porous thin film as the diaphragm 13.

[0022] The cathode flow channel plate 14 has a cathode flow channel 140. The cathode flow channel 140 faces the cathode 11. A cathode fluid containing a substance to be reduced and supplied to the cathode 11 can flow through the cathode flow channel 140. The cathode fluid may be humidified to contain water vapor. Reduction products are mainly contained in the cathode fluid and discharged from the cathode flow channel 140. The type of reduction product varies depending on the type of reduction catalyst, etc. Along with these gas products, steam or water obtained by condensation of steam contained in the humidified carbon dioxide gas is discharged from the cathode flow channel 140. In the electrolysis cell structure 101, when spaces (e.g., through holes such as vias) through which the cathode fluid flows are connected in series between multiple electrolysis cells 100, the cathode fluid discharged from one cathode flow channel 140 of multiple electrolysis cells 100 may be introduced directly into the inlet of the cathode flow channel 140 of an adjacent electrolysis cell.

[0023] The type of reduction product also depends on the composition of the cathode fluid. When the cathode fluid contains carbon dioxide gas or humidified carbon dioxide gas, the reduction products produced are primarily carbon monoxide gas and by-product hydrogen. When the cathode fluid contains nitrogen gas, the reduction products produced are primarily ammonia. When the cathode fluid contains impurity gases such as oxygen, the oxygen is reduced to produce water as a reduction product.

[0024] The cathode flow channels 140 are provided on the surface of the cathode flow channel plate 14. The cathode flow channel plate 14 has grooves (recesses) on its surface that form the cathode flow channels 140. The cathode flow channel plate 14 is preferably formed using a material that has low chemical reactivity and high conductivity. Examples of such materials include metal materials such as titanium (Ti) and SUS, and carbon. The flow channel plate material also includes materials that have low chemical reactivity and no conductivity. Examples of such materials include insulating resin materials such as acrylic resin, polyether ether ketone (PEEK), and fluororesin. The cathode flow channel plate 14 has screw holes for fastening. Packing may be inserted in front and behind each cathode flow channel plate 14 as needed. The cathode flow channels 140 may also be provided on the cathode current collector 16.

[0025] The cathode flow channel 140 has an inlet and an outlet, and a cathode fluid is supplied from the cathode supply source 60 via the inlet, and the cathode fluid containing the reduction products is discharged via the outlet. The cathode fluid flows through the cathode flow channel 140 so as to come into contact with the cathode 11. The cathode fluid discharged from the cathode flow channel 140 may contain unreacted substances to be reduced, etc.

[0026] The cathode flow channel plate 14 may have a land that contacts the cathode 11 for electrical connection with the cathode 11. The shape of the cathode flow channel 140 is not particularly limited as long as it is continuously connected, and examples include a serpentine structure in which a long and thin flow channel is bent. This is preferable because it allows the cathode fluid to flow uniformly over the surface of the cathode 11, allowing a uniform reaction to occur in the cathode 11.

[0027] The cathode fluid may be supplied in a dry state. When the cathode fluid contains carbon dioxide gas, the carbon dioxide concentration of the cathode fluid supplied from the cathode supply source 60 to the cathode flow path 140 does not have to be 100%. Fluids containing carbon dioxide gas discharged from various facilities can also be used as the cathode fluid. In this case, the cathode fluid may contain impurity gases. If the first gas contained in the cathode fluid is carbon dioxide gas, the second gas contained in the cathode fluid is a substance different from carbon dioxide, such as oxygen or nitrogen. The concentration of the second gas is lower than the concentration of the first gas, and is preferably, for example, 1 ppm or more and 100,000 ppm or less.

[0028] The cathode flow path plate 14 can be mainly formed from one material, but may also be formed from multiple different materials and stacked together. Furthermore, a surface treatment may be applied to part or the entire surface to impart hydrophilic or water-repellent properties.

[0029] The anode flow channel plate 15 has an anode flow channel 150. The anode flow channel 150 faces the anode 12. An anode fluid supplied to the anode 12 can flow through the anode flow channel 150. The anode fluid includes a liquid such as an anode solution.

[0030] The anode solution preferably contains at least water (HO). For example, when the substance to be reduced is carbon dioxide, the carbon dioxide is supplied from the cathode flow channel 140, and therefore the anode solution may or may not contain carbon dioxide.

[0031] The anode solution can be an aqueous solution (electrolyte) containing metal ions. For example, the aqueous solution can contain phosphate ions (PO4 2- ), borate ion (BO3 3- ), sodium ions (Na + ), potassium ions (K + ), calcium ions (Ca 2+ ), lithium ion (Li + ), cesium ions (Cs + ), magnesium ions (Mg 2+ ), chloride ions (Cl - ), bicarbonate ion (HCO3 - ) and the like. In addition, aqueous solutions containing lithium hydrogen carbonate (LiHCO3), sodium hydrogen carbonate (NaHCO3), potassium hydrogen carbonate (KHCO3), cesium hydrogen carbonate (CsHCO3), phosphoric acid, boric acid, and the like may also be used.

[0032] The anode flow channel 150 is provided on the surface of the anode flow channel plate 15. The anode flow channel plate 15 is used to supply an anode fluid to the anode 12 and has grooves (recesses) on its surface that form the anode flow channel 150. The anode flow channel plate 15 is preferably formed using a material that has low chemical reactivity and high conductivity. Examples of such materials include metal materials such as Ti and SUS, and carbon. The anode flow channel 150 may be provided on the anode current collector 17. The material of the anode flow channel plate 15 includes, for example, a material that has low chemical reactivity and no conductivity. Examples of such materials include insulating resin materials such as acrylic resin, polyether ether ketone (PEEK), and fluororesin. The anode flow channel plate 15 has screw holes for fastening (not shown).

[0033] The anode flow path plate 15 is generally made of a single material, but may also be made of a plurality of different materials stacked together. Furthermore, a surface treatment may be applied to a portion or the entire surface to impart hydrophilic or water-repellent properties.

[0034] The anode flow channel 150 has an inlet and an outlet, and the anode fluid is supplied from the anode supply source 70 via the inlet and discharged via the outlet. The anode fluid flows through the anode flow channel 150 so as to come into contact with the anode 12. The anode fluid discharged from the anode flow channel 150 may contain unreacted substances to be oxidized, the electrolyte, oxidation products, etc.

[0035] The anode flow channel plate 15 may have a land that contacts the anode 12 for electrical connection with the anode 12. The shape of the anode flow channel 150 is not particularly limited as long as it is continuously connected, and examples include a serpentine structure in which a long and thin flow channel is bent. This is preferable because it allows the anode fluid to flow uniformly over the surface of the anode 12, thereby enabling a uniform reaction to occur at the anode 12.

[0036] The cathode current collector 16 is electrically connected to the cathode 11. The cathode current collector 16 is in contact with the surface of the cathode flow path plate 14 opposite the cathode flow path 140. The cathode current collector 16 preferably contains a material that has low chemical reactivity and high conductivity. Examples of such materials include metal materials such as Ti and SUS, and carbon.

[0037] The anode current collector 17 is electrically connected to the anode 12. The anode current collector 17 is in contact with the surface of the anode flow path plate 15 opposite the anode flow path 150. The anode current collector 17 preferably contains a material that has low chemical reactivity and high conductivity. Examples of such materials include metal materials such as Ti and SUS, and carbon.

[0038] The insulating layer 18 is provided between the two electrolysis cells 100. The insulating layer 18 is formed using a material such as a material coated with a fluororesin such as silicone or polytetrafluoroethylene (PTFE), or an insulating resin material such as acrylic resin, polyether ether ketone (PEEK), or fluororesin. The electrolysis device 10 may have multiple insulating layers 18.

[0039] The electrolysis device 10 may have a reference electrode 19 as shown in FIG. 3. The reference electrode 19 is disposed, for example, between a plurality of electrolysis cells 100. The reference electrode 19 may also be provided between a plurality of insulating layers 18 as shown in FIG. 3. The reference electrode 19 may be connected to an impedance measuring device 21, for example, via wiring. The reference electrode 19 can be formed, for example, using a material that can be used for the cathode current collector 16 and the anode current collector 17. The electrolysis device 10 does not necessarily have to have a reference electrode 19.

[0040] The electrolysis cell 100 may be connected to a cathode supply source 60. The cathode supply source 60 may, for example, supply a cathode fluid to the electrolysis cell 100. The cathode supply source 60 is connected to an inlet of a cathode flow channel 140 of the electrolysis cell 100, for example, via a pipe. The cathode supply source 60 may be provided inside or outside the condition diagnostic system or the electrolysis system 1.

[0041] The electrolysis cell 100 may be connected to an anode supply source 70. The anode supply source 70 may, for example, supply an anode fluid to the electrolysis cell 100. The anode supply source 70 is connected to the inlet of the anode flow channel 150 of the electrolysis cell 100 via, for example, a pipe. The anode supply source 70 may be provided inside or outside the condition diagnostic system or the electrolysis system 1.

[0042] The electrolytic cell 100 may be connected to a power source 50. The power source 50 may, for example, supply current or voltage to the electrolytic cell 100. The power source 50 may supply AC and DC voltages. The power source supplying the DC component or the power source supplying the AC component may be built into the power source 50. Alternatively, the power source 50 may consist of two separate power sources, one supplying the AC component and the other supplying the DC component. The power source 50 may, for example, be electrically connected to the cathode current collector 16 via wiring. Multiple cathode current collectors 16 may be electrically connected to each other in parallel. The power source 50 may, for example, be electrically connected to the anode current collector 17 via wiring. Multiple anode current collectors 17 may be electrically connected to each other in parallel. The power source 50 may be provided inside or outside the condition diagnostic system or the electrolytic system 1.

[0043] Examples of the power source 50 are not limited to a conventional power grid or a battery, but may include a power source that supplies electricity generated by renewable energy sources such as solar cells and wind power. Using renewable energy is environmentally preferable in terms of both effective utilization of the substance to be reduced. The power source 50 may further include a power controller that adjusts the output of the power source 50 to control the voltage between the cathode 11 and the anode 12. The power source 50 may be provided external to the electrolysis device 10. The power source 50 controls the current or voltage supplied to the electrolytic cell 100 to achieve optimal operation of the electrolytic cell 100 and increase the reaction efficiency of the reduction reaction of the substance to be reduced at the cathode 11. Furthermore, adjusting the current or voltage supplied to each electrolytic cell 100 can achieve optimal operation of the electrolytic cell 100 and increase the reaction efficiency of the reduction reaction of the substance to be reduced at the cathode 11. A current monitoring element, such as a resistor, may be provided between the power source 50 and the electrolytic cell 100 or the electrolytic cell structure 101. This allows the voltage to be controlled to achieve optimal operation of the electrolysis cell 100, and the reaction efficiency of the reduction reaction at the cathode 11 to be increased.

[0044] Next, a description will be given of an example of a method for operating the electrolysis device 10. Here, the case where carbon monoxide is produced as a carbon compound will be mainly described, but the reduction product of carbon dioxide is not limited to carbon compounds.

[0045] First, it mainly oxidizes water (HO) to produce hydrogen ions (H + The reaction process for generating HO is described below. When a cathode fluid is supplied from a cathode supply source 60 to the cathode flow path 140, an anode fluid is supplied from an anode supply source 70 to the anode flow path 150, and an electric current is supplied from a power source 50 between the cathode 11 and the anode 12, an oxidation reaction of water (HO) occurs at the anode 12 in contact with the anode solution. Specifically, as shown in the following formula (1), the HO contained in the anode solution is oxidized to produce oxygen (O) and hydrogen ions (H + ) is generated.

[0046] 2H2O → 4H + +O2+4e - ···(1)

[0047] H generated at anode 12 + The electrons (e - ) and H that has moved to the vicinity of cathode 11 + This causes a reduction reaction of carbon dioxide. Specifically, as shown in the following formula (2), carbon dioxide supplied from the cathode flow channel 140 to the cathode 11 is reduced to produce carbon monoxide. Furthermore, hydrogen ions receive electrons as shown in the following formula (3), producing hydrogen. At this time, hydrogen may be produced simultaneously with carbon monoxide.

[0048] CO2+2H + +2e - → CO + H2O (2)

[0049] 2H + +2e - → H2···(3)

[0050] Next, carbon dioxide (CO2) is mainly reduced to hydroxide ions (OH - When a current is supplied from a power source between the cathode 11 and the anode 12, water (HO) and carbon dioxide (CO) are reduced near the cathode 11 to produce carbon monoxide (CO) and hydroxide ions (OH), as shown in the following formula (4): - ) are produced. Also, hydrogen is produced when water accepts electrons as shown in the following formula (5). At this time, hydrogen may be produced simultaneously with carbon monoxide. The hydroxide ions (OH - ) diffuses to the vicinity of the anode 12 and converts into hydroxide ions (OH - ) is oxidized to produce oxygen (O2).

[0051] 2CO2+2H2O+4e- → 2CO+4OH - ···(4)

[0052] 2H2O+2e - → H2+2OH - ···(5)

[0053] 4OH - → 2H2O+O2+4e - ···(6)

[0054] In this way, the electrolysis cell 100 can be specialized not only for the reduction of carbon dioxide, but also for producing reduction products and hydrogen in any ratio, such as producing carbon monoxide and hydrogen in a 1:2 ratio, followed by a chemical reaction to produce methanol.

[0055] Because hydrogen is a cheap and easily available raw material from water electrolysis and fossil fuels, the ratio of hydrogen does not need to be high. From these perspectives, it is preferable from the standpoint of economic efficiency and the environment that the ratio of carbon monoxide to hydrogen is at least 1, and preferably 1.5 or more.

[0056] Next, we will explain the reaction process when oxygen (O2) is reduced to produce water (H2O). When a current is supplied from a power source between the cathode 11 and the anode 12, oxygen (O2) is reduced near the cathode 11, producing water (H2O), as shown in the following formula (7). At this time, water may be produced simultaneously with carbon monoxide and hydrogen, but due to the difference in reduction potential, it is thought that the reduction of oxygen mainly proceeds. As shown in the following formula (8), water in the electrolyte is oxidized to produce oxygen (O2) and protons (H + ) is generated, and the protons (H + ) diffuses from the vicinity of the anode 12. Hydrogen peroxide (H2O2) may also be generated as an intermediate or product. The oxygen reduction reaction can be a two-electron reduction or a four-electron reduction, and can occur in both acidic and alkaline environments.

[0057] O2+4H + +4e -→ 2H2O (7)

[0058] 2H2O → O2+4H + +4e - ···(8)

[0059] Such an electrolysis cell 100 is not only specialized for reducing carbon dioxide, but can also reduce impurity gases such as oxygen and nitrogen even if they are present.

[0060] In the case of a nitrogen electrolysis device, ammonia can be produced by reducing nitrogen using the cathode 11. The configuration of the electrolysis device 10 can be appropriately applied to other components of the nitrogen electrolysis device.

[0061] The impedance measuring device 21 measures the complex impedance of the electrolytic cell 100 in the electrolysis system 10. The complex impedance is measured, for example, before or after the start of operation of the electrolysis system 10. The impedance measuring device 21 can obtain data indicating the complex impedance from at least one value of the modulated current or modulated voltage and at least one value of the voltage response or current response of the electrolytic cell 100 or the electrolytic cell structure 101 by, for example, supplying a modulated current or a modulated voltage between the cathode 11 and the anode 12 of the electrolysis cell 100. Note that modulation means changing a target value over time and also includes periodically changing a target value. The impedance measuring device 21 may obtain data indicating the complex impedance by, for example, supplying an AC current or an AC voltage between the cathode 11 and the anode 12 of the electrolysis cell 100. The measurement result of the complex impedance may include at least one signal or multiple signals selected from the group consisting of a DC current, a sine wave, a square wave, a triangular wave, a pulse, and noise. The complex impedance may be measured at multiple times during a predetermined period of time during operation of the electrolysis device 10. The measurement frequency of the complex impedance is, for example, in the range of 0 kHz to 1 GHz.

[0062] When impedance measurements are performed during operation of the electrolysis device 10, the voltage / current from the power supply 50 and the voltage / current from the impedance measuring device 21 may be superimposed and supplied between the cathode 11 and the anode 12. In this case, the current / voltage may be measured at the cathode 11 and the anode 12 and at separate measurement terminals connected to the impedance measuring device 21, the AC component may be extracted, and the resulting voltage / current may be divided by the input voltage / current to obtain a complex impedance value. Alternatively, a voltage / current obtained by superimposing a DC voltage / current component for electrolysis and an AC voltage / current component for impedance measurement may be supplied between the cathode 11 and the anode 12 from the power supply 50. In this case, setting information such as the frequency and amplitude of the AC component is sent as a signal from the impedance measuring device 21 to the power supply 50. In this case, the current / voltage may be measured at the cathode 11 and the anode 12 and at separate measurement terminals connected to the impedance measuring device 21, the AC component may be extracted, and the resulting voltage / current may be divided by the input voltage / current to obtain a complex impedance value.

[0063] The impedance measuring device 21 is provided separately from the power supply 50. The impedance measuring device 21 is connected in parallel or in series to the power supply 50. The impedance measuring device 21 may be electrically connected to the wiring between the electrolytic device 10 and the power supply 50. Even if the impedance measuring device 21 is not connected to the wiring between the electrolytic device 10 and the power supply 50, it is possible to similarly obtain measurement results of complex impedance by utilizing the effect of induction machine power due to electromagnetic induction or the like.

[0064] The complex impedance measurement may include a scalar value. The complex impedance measurement may include a vector value consisting of the modulation frequency and the real and imaginary parts of the impedance.

[0065] Data indicating the measurement results of the complex impedance is output from the impedance measuring device 21 and input to the processing unit 31. The impedance measuring device 21 may be connected to the processing unit 31 via a wired connection or a wireless connection.

[0066] The ammeter 22 is, for example, built into the power supply 50, and outputs the actual supply current value relative to the set constant current value. The ammeter 22 may be provided, for example, midway along the wiring connecting the electrolysis device 10 and the power supply 50. The ammeter 22 can measure the current flowing through the electrolysis device 10. The ammeter 22 may be provided in the measurement unit 23.

[0067] The processing unit 31 analyzes data indicating the complex impedance measurement results, determines the validity of the analysis results, and outputs data indicating the analysis results in which at least a portion of the frequency domain data of the measurement results is determined to be valid. The data indicating the analysis results is output from the processing unit 31 and input to the processing unit 32.

[0068] The storage unit 41 holds at least one piece of prior information data. The storage unit 41 is configured, for example, by a storage device including a database. It is preferable that the data held in the storage unit 41 cannot be rewritten and can only be read.

[0069] The advance information includes data indicating the correspondence between the state information of the electrolysis device 10 and the state diagnosis results of the electrolysis device 10, which is obtained before the start of operation of the electrolysis device 10. The state diagnosis results include degradation diagnosis results. The degradation diagnosis results indicate the causes of degradation at each time in the electrolysis device 10 during operation. The state information includes, for example, impedance information, and information on time changes such as data on operation information and its time derivatives.

[0070] The impedance information includes information indicating the analysis results of the complex impedance measurement results and information indicating the analysis validity of the complex impedance measurement results. The information indicating the analysis validity includes, for example, information on the determination result of whether the analysis result at each time during operation of the electrolysis device 10 is valid or invalid, information on the duration of each valid state and invalid state, and information on the residual obtained by fitting using the Lin-KK Test described below.

[0071] The operating information includes at least one parameter that represents the operating state of the electrolysis device 10. The operating information can be acquired by the measurement unit 23. The measurement unit 23 may have at least one detector that can measure a parameter related to the electrolysis device 10 that is different from the parameters measured by the impedance measurement device 21 and the ammeter 22.

[0072] Examples of parameters that can be measured by the at least one detector include the cell voltage of the electrolyzer 10, the cell temperature of the electrolyzer 10, the temperature of the cathode fluid, the temperature of the anode fluid, the temperature of the cathode fluid flowing at the inlet of the cathode flow channel 140, the temperature of the cathode fluid flowing at the outlet of the cathode flow channel 140, the temperature of the anode fluid flowing at the inlet of the anode flow channel 150, the temperature of the anode fluid flowing at the outlet of the anode flow channel 150, the flow rate of the cathode fluid, the flow rate of the anode fluid, the composition of the cathode fluid, the anode These parameters include the fluid composition, the Faraday efficiency of the oxidation product, the Faraday efficiency of the reduction product, the electrolyte concentration contained in the anode fluid, the pressure in the cathode flow channel 140, the pressure in the anode flow channel 150, the inlet pressure of the cathode flow channel 140, the outlet pressure of the cathode flow channel 140, the inlet pressure of the anode flow channel 150, the outlet pressure of the anode flow channel 150, the dew point of the cathode fluid, the pressure loss in the cathode flow channel 140, the pressure loss in the anode flow channel 150, the potential of the cathode 11, the potential of the anode 12, the potential of the reference electrode 19, etc. Data indicating these parameters is output from the measurement unit 23 and input to and stored in the memory unit 41.

[0073] The processing unit 32 outputs data indicating status information of the electrolysis device 10 based on at least one piece of first data including data indicating the analysis result of the complex impedance measurement result. The data indicating the status information of the electrolysis device 10 is output from the processing unit 32 and input to the storage unit 42. The at least one piece of first data may include data indicating a measured parameter from at least one detector of the measurement unit 23.

[0074] The storage unit 42 stores at least one second data including data indicating status information of the electrolysis device 10. The storage unit 42 may store at least one of the data output from the processing unit 31 and the data output from the processing unit 32. The data stored in the storage unit 42 is preferably updated or added, for example, while the electrolysis device 10 is operating. The storage unit 42 is configured, for example, by a storage device including a database.

[0075] The storage unit 41 may hold at least one piece of prior information about an electrolysis device 10 different from the electrolysis device 10 currently in operation. The at least one piece of prior information about the different electrolysis device 10 is read from the storage unit 41 to the processing unit 32 and used for condition diagnosis, such as deterioration diagnosis, and condition prediction, such as deterioration prediction, of the electrolysis device 10. This allows for highly accurate diagnosis of the current condition and prediction of the future condition of the electrolysis device 10.

[0076] The processing unit 33 reads at least one piece of prior information data from the storage unit 41 and at least one piece of second data from the storage unit 42, diagnoses the state of the electrolysis device 10 based on a plurality of data including the at least one piece of prior information data from the storage unit 41 and the at least one piece of second data from the storage unit 42, and outputs data indicating the diagnosis result. The diagnosis result includes, for example, a deterioration diagnosis result for the electrolysis device 10.

[0077] The processing units 31, 32, and 33 may be configured using hardware that uses, for example, a processor, etc. Note that each operation may be stored as an operation program in a computer-readable recording medium such as a memory, and each operation may be executed by the hardware by appropriately reading out the operation program stored in the recording medium.

[0078] The processing units 31, 32, and 33 may include personal computers, servers, edge devices, etc., and may be appropriately selected depending on the installation location of the electrolysis device 10. It is preferable that each processing unit can communicate in a format conforming to a communication standard such as a Universal Serial Bus (USB) cable or a Local Area Network (LAN) cable.

[0079] The processing units 31, 32, and 33 may be integrally configured by a single processor, or may be separately configured by multiple different processors. A series of processes may be processed by a single processor, or may be processed by multiple separate processors.

[0080] As described above, the condition diagnosis system and electrolysis system of the first embodiment can diagnose the condition of the electrolysis device 10 based on the measurement results of the complex impedance at each time and the operation information of the electrolysis device 10. At this time, by referring to the prior information stored in the storage unit 41, the condition of the electrolysis device 10 can be diagnosed with high accuracy. Furthermore, by referring to the state information of the electrolysis device stored in the storage unit 42, the condition of the electrolysis device 10 can be diagnosed with even higher accuracy. This makes it possible to diagnose, for example, the deterioration state of the electrolysis device 10.

[0081] Here, an example of analysis processing of complex impedance using fitting using the Lin-KK Test will be described. As described above, the electrolysis system and condition diagnosis system of the first embodiment can determine the analysis validity and effective analysis range of the complex impedance measurement results using the processing unit 31, distinguish between effective and invalid areas of the analysis results within the range determined to be effective, and output data indicating the analysis results within the effective analysis range to the processing unit 32 if the analysis is valid.

[0082] 4 is a flowchart showing an example of analysis processing by the processing unit 31. The processing unit 31 performs fitting using the Lin-KK test on data indicating the complex impedance measurement results from the impedance measuring device 21 (S1). The complex impedance measurement results can be determined to be valid from the perspective of analyzability if they satisfy linearity, time invariance, and causality with respect to the modulation signal. This validity can be determined, for example, by fitting a complex impedance spectrum that depends on the modulation frequency to an equivalent circuit model.

[0083] The equivalent circuit model is used to fit the complex impedance spectrum and consists of an ohmic resistance Rohm and M RC elements (M is a natural number). Rohm and the resistance component Rk of the M RC elements are free fitting parameters. It is guaranteed that the real and imaginary parts of the complex impedance of the equivalent circuit model satisfy the Kramers-Kronig relationship. Therefore, it can be said that the response signal of the equivalent circuit model to a modulation signal satisfies linearity, time invariance, and causality.

[0084] By fitting the complex impedance spectrum obtained by measuring the complex impedance of the electrolysis device 10 to the complex impedance spectrum of a corresponding appropriate equivalent circuit model, a residual error, which is an index of the goodness of fit, can be obtained. This is commonly known as the Lin-KK Test. Note that, as a method for evaluating the validity of the complex impedance measurement results other than the Lin-KK Test, the validity can also be evaluated by determining to what extent the real and imaginary parts of the complex impedance satisfy the Kramers-Kronig relationship.

[0085] Since this residual is calculated for the value of the complex impedance at each frequency component, the validity of the measurement result of the complex impedance at each frequency component can be quantitatively evaluated.

[0086] The smaller the residual error, the more valid the complex impedance measurement results are. For measurement results to be considered valid, the residual error is preferably within ±5%. Furthermore, the residual error is even more preferably within ±3%.

[0087] Fig. 5 shows an example of the measurement results of the complex impedance of the electrolysis device 10. Fig. 5 is a graph showing the frequency characteristics of the real part re and the imaginary part lm of the complex impedance. The horizontal axis of the graph represents the frequency [Hz] of the response signal. The vertical axis of the graph represents the amount of change Δ [%] in the response signal.

[0088] The electrolysis device 10 exhibiting the complex impedance shown in Figure 5 is fabricated as follows. The cathode 11 is formed using a laminate in which a catalyst layer is applied to a carbon substrate composed of a gas diffusion layer laminated with a microporous layer. The anode 12 is formed using a conductive, corrosion-resistant nonwoven fabric such as Ti coated with a catalyst such as iridium oxide (IrOx). The diaphragm 13 is formed using a porous film. The cathode flow path plate 14 is formed using a Ti plate with a flow path pattern on its surface. The anode flow path plate 15 is formed using a Ti plate with a flow path pattern on its surface. The cathode current collector 16 is formed using a gold-plated Ti plate. The anode current collector 17 is formed using a gold-plated Ti plate.

[0089] The electrolysis cell 100 is formed by stacking a cathode current collector 16, a cathode flow path plate 14, a cathode 11, a diaphragm 13, an anode 12, an anode flow path plate 15, and an anode current collector 17 in this order. Furthermore, a plurality of electrolysis cells 100 are stacked with an insulating layer 18 and a reference electrode 19 sandwiched between them to form a cell stack. The number of stacked electrolysis cells 100 is two or more, and may be several hundred. The cell stack is sandwiched between support plates and further fastened with bolts.

[0090] In the electrolysis device 10, carbon dioxide gas is supplied from the cathode supply source 60 to the cathode flow path 140 at a flow rate of 33.5 sccm, an aqueous potassium hydroxide solution (concentration: 1 M KOH) is introduced from the anode supply source 70 to the anode flow path 150 at a flow rate of 5 mL / min, and a current of 400 mA / cm is supplied from the power source 50 between the cathode 11 and the anode 12. 2 It is operated by passing a current at a current density of .

[0091] The complex impedance shown in Figure 5 is measured under the following measurement conditions, for example. The impedance measuring device 21 is a Bio-Logic VSP. The frequency range of the superimposed AC current, which is a single sine wave, is 0.01 Hz to 1 MHz, and its peak-to-peak amplitude is 5% to 40% of the applied current. The measurement mode is Galvano Electrochemical Impedance Spectroscopy mode. Note that results similar to those described here can be obtained even if the measurement conditions are not exactly the same. The reference electrode 19 is placed between multiple electrolytic cells 100, and the impedance between the cathode 11, anode 12, and reference electrode 19 is measured simultaneously. Note that similar results are obtained for complex impedance measurements between any of the electrodes.

[0092] Figure 6 shows a graph of the Lin-KK test results for the complex impedance measurement results shown in Figure 5. The horizontal axis of the graph in Figure 6 represents frequency [Hz]. The vertical axis of the graph in Figure 6 represents γ [Ω]. As shown in Figure 6, if the frequency is approximately 1000 Hz or less, the residual is within ±5%. Furthermore, if the frequency is approximately 500 Hz or less, the residual is within ±3%. Figure 5 shows both the residual of the real part of the impedance spectrum and the residual of the imaginary part of the impedance spectrum, but either the real part, the imaginary part, or both values ​​can be used as the evaluation criteria.

[0093] When the residual is greater than ±5%, the residual tends to rise sharply, but when the residual is within ±5%, such a steep rise in the residual is not observed. Furthermore, when the residual is within ±3%, the residual amplitude is even smaller. Note that, because measurement noise is essentially unavoidable, the residual will never be 0% unless it is a theoretical equivalent circuit model that does not contain noise. Therefore, a residual of 0% is considered to be a measurement result in which the object being measured is not measured correctly due to measurement errors or other factors. Therefore, if the lower limit of the residual is 0.001% or more or -0.001% or less, the possibility of such measurement errors can be eliminated and the result can be considered a valid complex impedance measurement result that does not contain measurement errors. However, since it is possible that residuals smaller than ±0.001% are obtained at several data points within the sweep frequency range, if the residual is 0.001% or more or -0.001% or less within a certain frequency range (e.g., 10 Hz width), data points with small residuals greater than 0% but less than 0.001%, or greater than -0.001% but less than 0%, can be considered not invalid.

[0094] Figure 6 shows the results of extracting characteristic frequency components using Distribution of Relaxation Times (DRT) analysis across the entire frequency range. Figure 6 also shows the results of analysis using Gaussian Process - Distribution of Relaxation Times (GP-DRT), one of the DRT analysis methods. In the case of the data shown in Figure 6, as shown in the gray area, the variance is large and the polarization resistance component cannot be extracted. For this reason, this data cannot be used to obtain valid analysis of complex impedance measurement results. γ indicates the partial resistance value of each peak component obtained by GP-DRT.

[0095] Next, Figure 7 shows an example of the results when a spectrum in a frequency range (1000 Hz or less) where the residual is within ±5% is extracted and a GP-DRT analysis is performed. As shown in the gray area in Figure 7, the variance is significantly reduced, making it possible to extract a spectral range where the polarization resistance component can be extracted. Furthermore, Figure 8 shows an example of the results when a spectrum in a frequency range (500 Hz or less) where the residual is within ±3% is extracted and a GP-DRT analysis is performed. As shown in the gray area in Figure 8, the variance is significantly reduced, making it possible to extract a spectral range where the polarization resistance component can be extracted.

[0096] As shown in FIG. 4, if the residual is within the specified range over the entire measurement frequency range (S2: Yes), the measurement results for all frequency ranges are analyzed as is (S3). If the residual is not within the specified range over the entire measurement frequency range (S2: No) and if the residual is within the specified range over part of the measurement frequency range (S4: Yes), only the measurement results for the frequency ranges where the residual is within the specified range are analyzed as valid data (S5). If the residual is not within the specified range over the entire measurement frequency range but is outside the specified range (S4: No), the measurement result cannot be analyzed (analysis not possible). In this case, the residual is recognized as being large, and the time at which the residual occurred is recorded. Furthermore, the complex impedance is measured at multiple subsequent times. If the residual remains large, it is determined that some deterioration is progressing in the electrolysis device 10, and data indicating a diagnosis result indicating an abnormality is output from the processing unit 31 (S6). The data indicating the diagnosis result indicating an abnormality may be input to a subsequent processing unit, such as the processing unit 35 described below, and used to control the operating conditions of the electrolysis device 10. Examples of the operating conditions include the value of the current supplied to the electrolysis device 10, etc.

[0097] In the analysis process, the processing unit 31 may analyze the time when the analysis was valid, the duration of the valid state, and the quantified degree of validity if the analysis was valid, or the time when the analysis was invalid, the duration of the invalid state, and the quantified degree of invalidity if the analysis was invalid. This makes it possible to distinguish between valid and invalid regions in the measurement results of complex impedance.

[0098] The processing unit 32 can output data indicating state information based on at least one first data including data indicating the analysis result by fitting from the processing unit 31.

[0099] As described above, the processing unit 31 performs fitting using the Lin-KK test and analyzes the complex impedance measurement results, thereby making it possible to diagnose the state of the electrolysis device 10 with high accuracy.

[0100] In degradation diagnosis and degradation prediction, it is necessary to confirm the validity of the complex impedance measurement results of the electrolysis device 10. However, the complex impedance measurement results are generally not considered valid unless they are in a steady state. Therefore, depending on the degradation mode of the electrolysis device 10, the electrolysis device 10 may be in an unsteady state where degradation has progressed significantly, making it difficult to obtain valid complex impedance measurement results.

[0101] Furthermore, in a typical analysis process of multiple impedance measurement results, even if some of the measurement frequency range is valid, if other ranges are invalid, the data is determined to be invalid and is not used to diagnose the state of the electrolysis device 10. For this reason, when the deterioration state is advanced, it is difficult to obtain valid complex impedance measurement results, and furthermore, it is difficult to diagnose the deterioration state in detail.

[0102] Furthermore, even if invalid complex impedance measurement results are obtained, information indicating these measurement results is not stored and utilized. Therefore, when the electrolysis device 10 is in an increasingly deteriorated state, information indicating that the deterioration state is continuing is not utilized, making it difficult to predict deterioration.

[0103] Furthermore, when diagnosing the condition of the electrolysis device 10 while the operation of the electrolysis device 10 is suspended, historical information regarding deterioration is unlikely to remain, and therefore there is insufficient information to diagnose the condition of the electrolysis device 10, making it difficult to improve the accuracy of the diagnosis.

[0104] In contrast, the condition diagnosis system and electrolysis system of the first embodiment analyze the measurement results of the complex impedance, and even if part of the measurement frequency is in an invalid range, as long as another part of the measurement frequency has a valid range, the analysis results of the measurement results in the valid range can be used to diagnose the condition of the electrolysis device 10. Therefore, the condition of the electrolysis device 10 can be diagnosed with high accuracy.

[0105] The deterioration diagnosis of a carbon dioxide electrolysis cell described in Non-Patent Document 1 is performed based on complex impedance measurement results and cell information obtained in advance. The effectiveness of the complex impedance measurement results is evaluated, but only by the root-mean-square error of the residuals integrated within the measurement frequency range. Therefore, even if there is a frequency range in which the residuals are high, the residuals are averaged by the frequency range in which the residuals are low, resulting in an underestimation of the residuals. Therefore, the effectiveness of the complex impedance measurement results is not evaluated with the same high accuracy as in the first embodiment. Furthermore, Non-Patent Document 1 evaluates the cell state only by the root-mean-square error of the residuals integrated within the measurement frequency range, without confirming the effective range of the measurement frequency range. From this perspective, the deterioration diagnosis accuracy is low and it is thought to only indicate the trend of cell performance.

[0106] The complex impedance measurement results shown in Figure 5 show that the current density is high (400 mA / cm 2 ) the residual is large by operating the electrolysis device 10 at a current density of 100 mA / cm 2 When the electrolysis device 10 is operated under the same conditions as those for the complex impedance measurement results shown in Fig. 5 except that the residual error can be reduced as shown in Fig. 9. Fig. 9 is a diagram showing another example of the complex impedance measurement results of the electrolysis device 10. Therefore, by changing the parameter values ​​included in the operation information of the electrolysis device 10 based on the residual error, an improvement in the residual error can be observed, and therefore the cell can be switched to steady-state operation.

[0107] (Second embodiment) 10 is a schematic diagram showing an example configuration of a condition diagnosis system and an electrolysis system according to the second embodiment. The electrolysis system and the condition diagnosis system according to the second embodiment differ from the electrolysis system and the condition diagnosis system according to the first embodiment in that they further include a processing unit 34 and a processing unit 35. The following describes the differences between the second embodiment and the first embodiment, and the description of the first embodiment can be used for the other parts as appropriate.

[0108] The processing unit 34 predicts the future state of the electrolysis device 10 based on at least one third data including data indicating the state diagnosis result from the processing unit 33, and generates data indicating the prediction result. The prediction result includes the state diagnosis result of the electrolysis device 10 during operation after a predetermined time has elapsed. The data indicating the prediction result is output from the processing unit 34 and input to the processing unit 35.

[0109] The processing unit 35 generates at least one control signal based on data indicating the prediction result from the processing unit 34. The at least one control signal is output from the processing unit 35 and input to the electrolysis device 10. The at least one control signal is a signal for controlling the operating state of the electrolysis device 10. Examples of the at least one control signal include parameter values ​​required for controlling the electrolysis device 10, such as a control signal for adjusting the current density of the current supplied to the electrolysis device 10, a control signal for adjusting the temperature of the electrolysis device 10, and a control signal for adjusting the flow rate of the cathode fluid supplied to the cathode flow channel 140. Without being limited thereto, the at least one control signal may include a control signal for adjusting at least one parameter detectable by the measurement unit 23.

[0110] The processing units 34 and 35 may be configured using hardware that uses, for example, a processor, etc. Note that each operation may be stored as an operation program in a computer-readable recording medium such as a memory, and each operation may be executed by the hardware by appropriately reading out the operation program stored in the recording medium.

[0111] The processing units 34 and 35 include personal computers, servers, edge devices, etc., and may be appropriately selected depending on the installation location of the electrolysis device 10. It is preferable that each processing unit can communicate via a format conforming to a communication standard such as a USB cable or a LAN cable.

[0112] Processing units 34 and 35 may be integrally configured by a single processor together with processing units 31, 32, and 33, or may be separately configured by multiple different processors. A series of processes may be processed by a single processor, or may be processed by multiple separate processors.

[0113] As described above, in the second embodiment, information indicating the current state of the electrolysis device 10 is referenced to predict the future state of the electrolysis device 10. This makes it possible to predict, for example, the deterioration of the electrolysis device 10 with high accuracy, and to suppress future deterioration of the electrolysis device 10 by detecting in advance that deterioration of the electrolysis device 10 will progress and adjusting various operating conditions of the electrolysis device 10 before the deterioration progresses.

[0114] Examples of the at least one control signal may include a control signal for adjusting the flow rate of the cathode fluid supplied to the cathode flow channel 140, a control signal for adjusting the anode fluid supplied to the anode flow channel 150, a control signal for adjusting the coolant for cooling the electrolysis device 10, a control signal for controlling the pressure in each flow channel of the electrolysis device 10, and a control signal for adjusting the electrolyte concentration contained in the anode fluid. By supplying these control signals from the processing unit 35 to the electrolysis device 10 and adjusting (modulating) each parameter, it is possible to lock in to small changes, and to more accurately diagnose and predict deterioration of the electrolysis device 10.

[0115] Furthermore, data indicating the results of the operation simulation of the electrolysis device 10 may be stored as data indicating prior information in the storage unit 41. This can further improve the accuracy of the deterioration diagnosis and deterioration prediction of the electrolysis device 10.

[0116] Furthermore, the degradation diagnosis results and degradation prediction results indicate current or future degradation factors of the electrolysis device 10. Examples of degradation factors include degradation of the diaphragm 13, degradation of the cathode catalyst provided in the cathode 11, degradation of the anode catalyst provided in the anode 12, occurrence of flooding due to operation of the electrolysis device 10, salt deposition due to operation of the electrolysis device 10, poor tightening of the electrolysis cell 100, and electrical short circuit of the electrolysis cell 100. The second embodiment can perform detailed degradation diagnosis and degradation prediction of the electrolysis device 10 for these degradation factors.

[0117] The processing unit 34 may perform analysis by a time-series machine learning model using at least one piece of third data, thereby enabling deterioration diagnosis and deterioration prediction of the electrolysis device 10 to be performed with even higher accuracy.

[0118] The second embodiment can be combined with the first embodiment as appropriate.

[0119] (Third embodiment) 11 is a schematic diagram showing an example configuration of a condition diagnosis system and an electrolysis system according to the third embodiment. The electrolysis system according to the third embodiment differs from the electrolysis system according to the second embodiment in that it further includes a sensor 24, a sensor 25, a storage unit 43, and a processing unit 36. The following describes the differences between the third embodiment and the second embodiment, and the description of the second embodiment can be used for the other parts as appropriate.

[0120] The sensor 24 can analyze and monitor the fluid in real time, for example, by detecting the composition of the fluid introduced into the electrolysis device 10. Examples of the sensor 24 include a microelectromechanical systems (MEMS) sensor and a gas chromatograph. The electrolysis system 1 may have multiple sensors 24. One of the multiple sensors 24 may be provided, for example, midway through the flow path connecting the cathode supply source 60 and the inlet of the cathode flow path 140 or connected to the flow path, and can detect the composition of the cathode fluid supplied from the cathode supply source 60 to the cathode flow path 140. Another of the multiple sensors 24 may be provided, for example, midway through the flow path connecting the anode supply source 70 and the inlet of the anode flow path 150 or connected to the flow path, and can detect the composition of the anode fluid supplied from the anode supply source 70 to the anode flow path 150. The sensor 24 may be provided in the measurement unit 23. The detection results of the sensor 24 may change from moment to moment.

[0121] The sensor 25 can analyze and monitor the fluid in real time, for example, by detecting the composition of the fluid discharged from the electrolysis device 10. Examples of the sensor 25 include a MEMS sensor and a gas chromatograph. The electrolysis system 1 may have multiple sensors 25. One of the multiple sensors 25 can detect the composition of the cathode fluid discharged from the cathode flow channel 140. Another of the multiple sensors 25 can detect the composition of the anode fluid discharged from the anode flow channel 150. The sensor 25 may be provided in the measurement unit 23. The detection results of the sensor 25 may change from moment to moment.

[0122] The storage unit 43 holds data indicating at least one piece of external information. Examples of the data indicating at least one piece of external information include data indicating the supply and demand situation of renewable energy, data indicating the supply availability of at least one of the cathode fluid and the anode fluid, data indicating the state of a downstream process in the electrolysis device 10, and data indicating market information for carbon credits. The storage unit 43 is, for example, configured by a storage device including a database.

[0123] The supply and demand situation of renewable energy is expressed, for example, by the amount of power generated by renewable energy.

[0124] The supply availability of at least one fluid is represented, for example, by the composition and flow rate of the cathode fluid supplied from the cathode supply source 60, or the composition and flow rate of the anode fluid supplied from the anode supply source 70. In this case, by adjusting the power supplied to the electrolysis device 10, the current or future operating efficiency of the electrolysis device 10 can be improved.

[0125] The state of the downstream process is expressed, for example, by the conversion efficiency (reaction rate) of the reduction products in a downstream device that is connected downstream of the electrolysis device 10 and generates valuable materials such as compounds through chemical reactions using the reduction products. Examples of chemical reactions include reactions using the Fischer-Tropsch process (FT process).

[0126] Carbon credit market information is expressed by fluctuation information of compensation for carbon dioxide reduction, etc.

[0127] The processing unit 36 ​​prepares an operation plan or maintenance plan for the electrolysis device 10 based on a plurality of data including, for example, data indicating analysis results, data indicating diagnosis results, data indicating prediction results, composition detection results by the sensors 24 and 25, and data indicating at least one piece of external information read out from the memory unit 43.

[0128] If at least one of the external information includes carbon credit market information, the current operating conditions can be fed back to the electrolyzer 10 to increase profits in the carbon credit market.

[0129] The processing unit 36 ​​can generate at least one control signal for adjusting the operating conditions of the electrolysis device 10 based on the operation plan. The generated control signal is output from the processing unit 36 ​​and input to the electrolysis device 10. This can increase the conversion efficiency of reduction products in a downstream device, for example.

[0130] The processing unit 36 ​​may be configured using hardware that uses, for example, a processor, etc. Note that each operation may be stored as an operation program in a computer-readable recording medium such as a memory, and each operation may be executed by the hardware by appropriately reading out the operation program stored in the recording medium.

[0131] The processing unit 36 ​​includes a personal computer, a server, an edge device, etc., and is appropriately selected depending on the installation location of the electrolysis device 10. The processing unit 36 ​​is preferably capable of communication in a format conforming to a communication standard such as a USB cable or a LAN cable.

[0132] Processing unit 36 ​​may be integrally configured by a single processor together with processing units 31, 32, 33, 34, and 35, or may be configured separately by multiple different processors. A series of processes may be processed by a single processor, or may be processed by multiple separate processors.

[0133] The processing unit 36 ​​may create an operation plan for the electrolysis device 10 based on the above-mentioned plurality of input data, and output a control signal for controlling the allocation of the amount of cathode fluid supplied to the plurality of electrolysis cells 100 in accordance with the operation plan. By controlling the allocation, the load due to the reduction reaction can be distributed according to the state of each electrolysis cell 100, and the operation state of the electrolysis device 10 can be adjusted to synchronize with the state of a downstream process, for example.

[0134] The processing unit 36 ​​may create a maintenance plan for the electrolysis device 10 based on the above multiple pieces of input data, generate a control signal in accordance with the maintenance plan, and feed it back to the electrolysis device 10. This prevents future deterioration of the electrolysis device 10 and maximizes the efficiency of downstream processes. Furthermore, cooperative control of the electrolysis device 10 and downstream processes can realize an efficient electrolysis system 1.

[0135] The operation plan or maintenance plan is automatically generated, but it is also possible for the user to change the operation plan through input. In addition, there does not have to be just one operation plan; multiple operation plans or multiple maintenance plans can be presented to the user, and the user can select an operation plan or maintenance plan according to their preference.

[0136] The storage unit 43 may store data indicating a maintenance plan for the electrolysis devices 10 nationwide or worldwide. This allows the processing unit 36 ​​to plan, for example, a route that can supply replacement parts required for the electrolysis device 10 to the user in the shortest time and over the shortest distance, in accordance with the maintenance plan read out from the storage unit 43. This reduces the waiting time until replacement parts are supplied, and shortens the maintenance time for the electrolysis device 10.

[0137] Furthermore, similar to the first embodiment, by analyzing the measurement results of the complex impedance of the electrolysis device 10, the internal state of the electrolysis device 10 can be grasped, and for example, deterioration diagnosis and deterioration prediction of the electrolysis device 10 can be performed.

[0138] If the electrolysis device 10 is in operation, the current deterioration of the electrolysis device 10 can be diagnosed and future deterioration of the electrolysis device 10 can be predicted from the analysis results of the complex impedance measurement results.

[0139] If the operation of the electrolysis device 10 is stopped (suspended), the current deterioration of the electrolysis device 10 can be diagnosed from the analysis results of the complex impedance measurement results, and deteriorated components can be identified without disassembling the electrolysis device 10. Depending on the deteriorated components and their degree of deterioration and the deterioration situation, the performance of the electrolysis device 10 can be restored by performing a refresh operation without disassembling the electrolysis device 10, and the life of the electrolysis device 10 can be expected to be extended. Even if it is determined that disassembly is necessary to restore the electrolysis device 10, the components that need to be replaced can be identified, so only those components need to be replaced, and it is expected that the cells and stacks can be reused and recycled efficiently.

[0140] Furthermore, by storing data on at least one of the above external information in the storage unit 43 together with the status information of the electrolysis device 10 and predicting deterioration, abnormalities, and lifespan while referring to this information, it is possible to, for example, automatically create a maintenance plan for the electrolysis device 10. This makes it possible to reduce the number of maintenance operations and improve the availability rate.

[0141] The configurations of the above-described embodiments can be applied in combination with each other, and some of them can be replaced with other configurations. Although several embodiments of the present invention have been described herein, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, modifications, etc. can be made without departing from the spirit of the invention. These embodiments and their modifications are intended to be included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as set forth in the claims.

[0142] The above embodiments can be summarized in the following technical solutions. (Technical proposal 1) A condition diagnosis system for diagnosing a condition of an electrolysis device, comprising: the electrolysis device includes an electrolysis cell; the electrolysis cell has an anode, a cathode, and a diaphragm separating the anode and the cathode; The condition diagnostic system includes: an impedance measuring device that measures the complex impedance of the electrolysis device and outputs data indicating the measurement results of the complex impedance; a first storage unit that stores at least one piece of prior information data, the data being acquired before the start of operation of the electrolytic device and including data indicating a correspondence relationship between status information of the electrolytic device and a diagnosis result of the status of the electrolytic device; a first processing unit that analyzes data indicating the complex impedance measurement results, determines the validity of the analysis results, and outputs data indicating the analysis results in which data in at least a part of the frequency domain of the measurement results is determined to be valid; a second processing unit that outputs data indicating the state information based on at least one first data including data indicating the analysis result; a second storage unit that stores at least one second data item including data indicating the status information; a third processing unit that diagnoses a state of the electrolysis device based on a plurality of data including the at least one piece of prior information data from the first storage unit and the at least one piece of second data from the second storage unit, and outputs data indicating a diagnosis result of the state; Equipped with Condition diagnostic system. (Technical proposal 2) The first processing unit includes: By the analysis, the analytical validity and analytical valid range of the complex impedance measurement result are determined, and a valid region and an invalid region of the complex impedance measurement result are distinguished; outputting data indicating the analysis results in the effective region; A condition diagnosis system as described in Technical Proposal 1. (Technical proposal 3) a fourth processing unit that predicts a future state of the electrolysis device based on at least one third data including data indicating a diagnosis result of the state from the third processing unit, and outputs data indicating a prediction result; A condition diagnosis system as described in Technical Proposal 1. (Technical proposal 4) The first processing unit includes: By the analysis, the validity and valid range of the analysis of the complex impedance measurement results are determined, and a valid region and an invalid region of the measurement results are distinguished; outputting data indicating the analysis results in the effective region; A condition diagnosis system as described in Technical Proposal 3. (Technical proposal 5) the electrolysis device; A condition diagnosis system according to Technical Proposal 3; Equipped with The condition diagnostic system includes: further comprising a fifth processing unit that outputs a control signal for controlling an operating state of the electrolysis device based on data indicating the prediction result from the fourth processing unit; Electrolysis system. (Technical proposal 6) a sensor that detects the composition of at least one fluid supplied to the electrolytic cell and the composition of at least one fluid discharged from the electrolytic cell, and outputs data indicative of the detected composition; a third storage unit configured to store data indicating at least one piece of external information selected from the group consisting of data indicating a supply and demand situation of renewable energy, data indicating the supply availability of the at least one fluid, data indicating a state of a downstream process of the electrolysis device, and data indicating market information of carbon credits; a sixth processing unit that creates an operation plan for the electrolysis device based on a plurality of data including data indicating the analysis results, data indicating the state diagnosis results, data indicating the prediction results, the composition detection results, and data indicating the at least one piece of external information; Further comprising: The electrolysis system described in Technical Proposal 5. (Technical proposal 7) the electrolysis device has a plurality of the electrolysis cells, the sixth processing unit creates an operation plan for the electrolysis device based on the plurality of data, and outputs a control signal for controlling the allocation of the supply amount of the cathode fluid to the plurality of electrolysis cells in accordance with the operation plan. The electrolysis system described in Technical Proposal 6. (Technical proposal 8) a sensor that detects the composition of at least one fluid supplied to the electrolysis device and the composition of at least one fluid discharged from the electrolysis cell, and outputs data indicative of the detected composition; a third storage unit configured to store data indicating at least one piece of external information selected from the group consisting of data indicating a supply and demand situation of renewable energy, data indicating the supply availability of the at least one fluid, data indicating a state of a downstream process of the electrolysis device, and data indicating market information of carbon credits; a sixth processing unit that creates a maintenance plan for the electrolytic device based on a plurality of data including data indicating the analysis results, data indicating the state diagnosis results, data indicating the prediction results, the composition detection results, and data indicating the at least one piece of external information; Further comprising: The electrolysis system described in Technical Proposal 5. (Technical proposal 9) the third storage unit holds data indicating a maintenance plan for electrolysis devices nationwide or worldwide; the sixth processing unit plans a route capable of supplying replacement parts required for the electrolysis device in the shortest time and over the shortest distance in accordance with the maintenance plan; The electrolysis system described in Technical Proposal 8. (Technical proposal 10) the complex impedance measurement result includes at least one signal selected from the group consisting of a direct current, a sine wave, a square wave, a triangular wave, a pulse, and noise; The measurement frequency of the complex impedance is in the range of 0 kHz to 1 GHz. The electrolysis system according to any one of Technical Schemes 5 to 9. (Technical proposal 11) the first processing unit performs a fitting process using an equivalent circuit model on data indicating the measurement results of the complex impedance, and determines that the measurement results in a region where the calculated residual value is within ±5% are valid regions. The electrolysis system according to any one of Technical Schemes 5 to 10. (Technical proposal 12) The first processing unit determines the measurement result of a region where the residual value is within ±3% as the valid region. Electrolysis system described in Technical Proposal 11. (Technical proposal 13) the sixth processing unit outputs at least one control signal for controlling at least one of a flow rate of at least one fluid supplied to the electrolysis device, a composition of at least one fluid supplied to the electrolysis device, a temperature of the electrolysis device, and a pressure of the electrolysis device in accordance with the operation plan or the maintenance plan. An electrolysis system according to Technical Scheme 6 or Technical Scheme 8. (Technical proposal 14) The at least one piece of prior information data is the data further includes at least one selected from the group consisting of data indicating operation information of the electrolytic device acquired before the start of operation of the electrolytic device, data indicating operation information of a second electrolytic device different from the electrolytic device, and data indicating an operation simulation result of the electrolytic device; The electrolysis system according to any one of Technical Schemes 5 to 9. (Technical proposal 15) the operating information includes at least one parameter selected from the group consisting of a temperature of the electrolytic device, a temperature of the cathode fluid supplied to the electrolytic device, a temperature of the anode fluid supplied to the electrolytic device, a flow rate of the cathode fluid, a composition of the cathode fluid, a cell voltage of the electrolytic device, a Faraday efficiency of at least one product produced by the electrolytic device, an electrolyte concentration contained in the anode fluid, an inlet pressure of a cathode flow channel facing the cathode, an inlet pressure of an anode flow channel facing the anode, an outlet pressure of the cathode flow channel, an outlet pressure of the anode flow channel, a potential of a reference electrode, a dew point of the cathode fluid, a pressure loss in the cathode flow channel, a pressure loss in the anode flow channel, a temperature of the anode fluid at an inlet of the anode flow channel, and a temperature of the anode fluid at an outlet of the anode flow channel; Electrolysis system described in Technical Proposal 14. (Technical proposal 16) the state information includes at least one piece of information selected from the group consisting of the operation information, the validity of the analysis, the validity range of the analysis, the analysis result, and information relating to changes therein over time; Electrolysis system described in Technical Proposal 14. (Technical proposal 17) the status diagnosis result indicates the current deterioration factors of the electrolysis device; the deterioration factor includes at least one selected from the group consisting of deterioration of the diaphragm, deterioration of a cathode catalyst provided in the cathode, deterioration of an anode catalyst provided in the anode, flooding due to operation of the electrolysis device, salt deposition due to operation of the electrolysis device, loose fastening of the electrolysis cell, and an electrical short circuit of the electrolysis cell. The electrolysis system according to any one of Technical Schemes 5 to 9. (Technical proposal 18) the state diagnosis result indicates future deterioration factors of the electrolysis device; the deterioration factor includes at least one selected from the group consisting of deterioration of the diaphragm, deterioration of a cathode catalyst provided in the cathode, deterioration of an anode catalyst provided in the anode, flooding due to operation of the electrolysis device, salt deposition due to operation of the electrolysis device, loose fastening of the electrolysis cell, and an electrical short circuit of the electrolysis cell. The electrolysis system according to any one of Technical Schemes 5 to 9. (Technical proposal 19) The electrolysis device further includes a reference electrode connected to the impedance measurement device. An electrolysis system according to any one of Technical Schemes 5 to 18. (Technical proposal 20) the fourth processing unit predicts a future state of the electrolysis device by performing analysis using a time-series machine learning model using the at least one piece of third data, and outputs data indicating the prediction result. The electrolysis system according to any one of Technical Schemes 5 to 9. (Technical proposal 21) The electrolysis device reduces carbon dioxide to produce carbon compounds or reduces nitrogen to produce ammonia. An electrolysis system that is one of Technical Option 5 to Technical Option 20. (Technical proposal 22) A method for diagnosing a state of an electrolysis device, comprising: the electrolysis device includes an electrolysis cell; the electrolysis cell has an anode, a cathode, and a diaphragm separating the anode and the cathode; The condition diagnosis method includes: measuring the complex impedance of the electrolytic cell using an impedance measuring device, and outputting data indicating the measurement result of the complex impedance from the impedance measuring device; a first processing unit that analyzes data indicating the measurement results of the complex impedance, determines the validity of the analysis results, and outputs data indicating the analysis results in which data in at least a part of the frequency domain of the measurement results is determined to be valid; outputting data indicating state information of the electrolysis device based on at least one first data including data indicating the analysis result by a second processing unit; a third processing unit reads from a first storage unit at least one piece of preliminary information data, the data being acquired before the start of operation of the electrolytic device and including data indicating a correspondence between the state information and a diagnosis result of the state of the electrolytic device; reads from a second storage unit at least one piece of second data including data indicating the state information; diagnoses the state of the electrolytic device based on a plurality of data including the at least one piece of preliminary information data from the first storage unit and the at least one piece of second data from the second storage unit; and outputs data indicating the diagnosis result of the state; How to diagnose the condition. [Explanation of symbols]

[0143] 1...electrolysis system, 10...electrolysis device, 11...cathode, 12...anode, 13...diaphragm, 14...cathode flow path plate, 15...anode flow path plate, 16...cathode current collector, 17...anode current collector, 18...insulating layer, 19...reference electrode, 21...impedance measuring device, 22...ammeter, 23...measuring unit, 24...sensor, 25...sensor, 31...processing unit, 32...processing unit, 33...processing unit, 34...processing unit, 35...processing unit, 36...processing unit, 41...memory unit, 42...memory unit, 43...memory unit, 50...power source, 60...cathode supply source, 70...anode supply source, 100...electrolytic cell, 101...electrolytic cell structure, 130...support plate, 140...cathode flow path, 150...anode flow path, MEA...membrane electrode assembly.

Claims

1. A condition diagnosis system for diagnosing a condition of an electrolysis device, comprising: the electrolysis device includes an electrolysis cell; the electrolysis cell has an anode, a cathode, and a diaphragm separating the anode and the cathode; The condition diagnostic system includes: an impedance measuring device that measures the complex impedance of the electrolysis device and outputs data indicating the measurement results of the complex impedance; a first storage unit that stores at least one piece of prior information data, the data being acquired before the start of operation of the electrolysis device and including data indicating a correspondence relationship between status information of the electrolysis device and a diagnosis result of the status of the electrolysis device; a first processing unit that analyzes data indicating the complex impedance measurement results, determines the validity of the analysis results, and outputs data indicating the analysis results in which data in at least a part of the frequency domain of the measurement results is determined to be valid; a second processing unit that outputs data indicating the state information based on at least one first data including data indicating the analysis result; a second storage unit that stores at least one second data item including data indicating the status information; a third processing unit that diagnoses a state of the electrolysis device based on a plurality of data including the at least one piece of advance information data from the first storage unit and the at least one piece of second data from the second storage unit, and outputs data indicating a diagnosis result of the state; Equipped with Condition diagnostic system.

2. The first processing unit includes: By the analysis, the analytical validity and analytical valid range of the complex impedance measurement result are determined, and a valid region and an invalid region of the complex impedance measurement result are distinguished; outputting data indicating the analysis results in the effective region; The condition diagnosis system according to claim 1 .

3. a fourth processing unit that predicts a future state of the electrolysis device based on at least one third data including data indicating a diagnosis result of the state from the third processing unit, and outputs data indicating a prediction result; The condition diagnosis system according to claim 1 .

4. The first processing unit includes: By the analysis, the validity and valid range of the analysis of the complex impedance measurement results are determined, and a valid region and an invalid region of the measurement results are distinguished; outputting data indicating the analysis results in the effective region; The condition diagnosis system according to claim 3 .

5. the electrolysis device; A condition diagnosis system according to claim 3; Equipped with The condition diagnostic system includes: further comprising a fifth processing unit that outputs a control signal for controlling an operating state of the electrolysis device based on data indicating the prediction result from the fourth processing unit; Electrolysis system.

6. a sensor that detects the composition of at least one fluid supplied to the electrolytic cell and the composition of at least one fluid discharged from the electrolytic cell, and outputs data indicative of the detected composition; a third storage unit configured to store data indicating at least one piece of external information selected from the group consisting of data indicating a supply and demand situation of renewable energy, data indicating the supply availability of the at least one fluid, data indicating a state of a downstream process of the electrolysis device, and data indicating market information of carbon credits; a sixth processing unit that creates an operation plan for the electrolysis device based on a plurality of data including data indicating the analysis results, data indicating the state diagnosis results, data indicating the prediction results, the composition detection results, and data indicating the at least one piece of external information; Further comprising:

6. The electrolysis system according to claim 5.

7. the electrolysis device has a plurality of the electrolysis cells, the sixth processing unit creates an operation plan for the electrolysis device based on the plurality of data, and outputs a control signal for controlling the allocation of the supply amount of the cathode fluid to the plurality of electrolysis cells in accordance with the operation plan.

7. The electrolysis system of claim 6.

8. a sensor that detects the composition of at least one fluid supplied to the electrolysis device and the composition of at least one fluid discharged from the electrolysis cell, and outputs data indicative of the detected composition; a third storage unit configured to store data indicating at least one piece of external information selected from the group consisting of data indicating a supply and demand situation of renewable energy, data indicating the supply availability of the at least one fluid, data indicating a state of a downstream process of the electrolysis device, and data indicating market information of carbon credits; a sixth processing unit that creates a maintenance plan for the electrolytic device based on a plurality of data including data indicating the analysis results, data indicating the state diagnosis results, data indicating the prediction results, the composition detection results, and data indicating the at least one piece of external information; Further comprising:

6. The electrolysis system according to claim 5.

9. the third storage unit holds data indicating a maintenance plan for electrolysis devices nationwide or worldwide; the sixth processing unit plans a route capable of supplying replacement parts required for the electrolysis device in the shortest time and over the shortest distance in accordance with the maintenance plan; 9. The electrolysis system of claim 8.

10. the complex impedance measurement result includes at least one signal selected from the group consisting of a direct current, a sine wave, a square wave, a triangular wave, a pulse, and noise; The measurement frequency of the complex impedance is in the range of 0 kHz to 1 GHz.

10. The electrolysis system according to claim 5.

11. the first processing unit performs a fitting process using an equivalent circuit model on data indicating the measurement results of the complex impedance, and determines that the measurement results in a region where the calculated residual value is within ±5% are valid regions.

10. The electrolysis system according to claim 5.

12. the first processing unit determines the measurement result of a region in which the residual value is within ±3% as the valid region; 12. The electrolysis system of claim 11.

13. the sixth processing unit outputs at least one control signal for controlling at least one of a flow rate of at least one fluid supplied to the electrolysis device, a composition of at least one fluid supplied to the electrolysis device, a temperature of the electrolysis device, and a pressure of the electrolysis device in accordance with the operation plan or the maintenance plan. The electrolysis system according to claim 6 or 8.

14. The at least one piece of prior information data is the data further includes at least one selected from the group consisting of data indicating operation information of the electrolytic device acquired before the start of operation of the electrolytic device, data indicating operation information of a second electrolytic device different from the electrolytic device, and data indicating an operation simulation result of the electrolytic device; 10. The electrolysis system according to claim 5.

15. the operating information includes at least one parameter selected from the group consisting of a temperature of the electrolytic device, a temperature of the cathode fluid supplied to the electrolytic device, a temperature of the anode fluid supplied to the electrolytic device, a flow rate of the cathode fluid, a composition of the cathode fluid, a cell voltage of the electrolytic device, a Faraday efficiency of at least one product produced by the electrolytic device, an electrolyte concentration contained in the anode fluid, an inlet pressure of a cathode flow channel facing the cathode, an inlet pressure of an anode flow channel facing the anode, an outlet pressure of the cathode flow channel, an outlet pressure of the anode flow channel, a potential of a reference electrode, a dew point of the cathode fluid, a pressure loss in the cathode flow channel, a pressure loss in the anode flow channel, a temperature of the anode fluid at an inlet of the anode flow channel, and a temperature of the anode fluid at an outlet of the anode flow channel; 15. The electrolysis system of claim 14.

16. the state information includes at least one piece of information selected from the group consisting of the operation information, the validity of the analysis, the validity range of the analysis, the analysis result, and information relating to changes therein over time; 15. The electrolysis system of claim 14.

17. the status diagnosis result indicates the current deterioration factors of the electrolysis device; the deterioration factor includes at least one selected from the group consisting of deterioration of the diaphragm, deterioration of a cathode catalyst provided in the cathode, deterioration of an anode catalyst provided in the anode, flooding due to operation of the electrolysis device, salt deposition due to operation of the electrolysis device, loose fastening of the electrolysis cell, and an electrical short circuit of the electrolysis cell.

10. The electrolysis system according to claim 5.

18. the state diagnosis result indicates future deterioration factors of the electrolysis device; the deterioration factor includes at least one selected from the group consisting of deterioration of the diaphragm, deterioration of a cathode catalyst provided in the cathode, deterioration of an anode catalyst provided in the anode, flooding due to operation of the electrolysis device, salt deposition due to operation of the electrolysis device, loose fastening of the electrolysis cell, and an electrical short circuit of the electrolysis cell.

10. The electrolysis system according to claim 5.

19. The electrolysis device further includes a reference electrode connected to the impedance measurement device.

10. The electrolysis system according to claim 5.

20. the fourth processing unit predicts a future state of the electrolysis device by performing analysis using a time-series machine learning model using the at least one third data, and outputs data indicating the prediction result.

10. The electrolysis system according to claim 5.

21. The electrolysis device reduces carbon dioxide to produce carbon compounds or reduces nitrogen to produce ammonia.

10. The electrolysis system according to any one of claims 5 to 9.

22. A method for diagnosing a state of an electrolysis device, comprising: the electrolysis device includes an electrolysis cell; the electrolysis cell has an anode, a cathode, and a diaphragm separating the anode and the cathode; The condition diagnosis method includes: measuring the complex impedance of the electrolytic cell using an impedance measuring device, and outputting data indicating the measurement result of the complex impedance from the impedance measuring device; a first processing unit that analyzes data indicating the measurement results of the complex impedance, determines the validity of the analysis results, and outputs data indicating the analysis results in which data in at least a part of the frequency domain of the measurement results is determined to be valid; outputting data indicating state information of the electrolysis device based on at least one first data including data indicating the analysis result by a second processing unit; a third processing unit reads from a first storage unit at least one piece of preliminary information data, the data being acquired before the start of operation of the electrolytic device and including data indicating a correspondence between the state information and a diagnosis result of the state of the electrolytic device; reads from a second storage unit at least one piece of second data including data indicating the state information; diagnoses the state of the electrolytic device based on a plurality of data including the at least one piece of preliminary information data from the first storage unit and the at least one piece of second data from the second storage unit; and outputs data indicating the diagnosis result of the state; How to diagnose the condition.

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