State diagnosis system, state diagnosis method, and electrolysis system

Abstract

The invention provides a state diagnosis system, a state diagnosis method, and an electrolysis system. A state diagnosis system for diagnosing the state of an electrolysis device is provided with: an impedance measurement device for outputting data indicating the measurement result of the complex impedance of the electrolysis device; a first storage unit that holds data including at least one piece of advance information including data indicating a correspondence relationship between the state information of the electrolysis device and a diagnosis result of the state of the electrolysis device; a first processing unit that analyzes the data indicating the measurement result of the complex impedance, determines the validity of the analysis result, and outputs the data indicating the analysis result for determining that the data in the frequency domain of at least a part of the measurement result is valid; a second processing unit that outputs data indicating status information on the basis of at least one piece of first data including data indicating an analysis result; a second storage unit that holds at least one piece of second data including data indicating state information; and a third processing unit that outputs data indicating a diagnosis result of the state of the electrolysis device on the basis of a plurality of data including the data of the prior information and the second data.

Description

[0001] This application is based on Japanese Patent Application No. 2024-44683 (filing date: March 21, 2024), and claims the benefit of priority from the aforementioned application. This application incorporates all the contents of the aforementioned application by reference. Technical Field

[0002] Embodiments of the present invention relate to a state diagnosis system, a state diagnosis method, and an electrolysis system. Background Art

[0003] In recent years, driven by both energy and environmental concerns, there has been a desire to not only convert renewable energy sources like solar power generation into electricity for utilization, but also to convert it into a form that can be stored and transported. To address this desire, artificial photosynthesis technologies, such as those used by plants to generate chemicals using sunlight, have been developed. This technology offers the potential to store renewable energy as storable fuel and also promises to generate value by producing chemicals that can serve as industrial raw materials.

[0004] As a device for generating chemical substances using renewable energy sources such as solar power generation, for example, it is known to have an electrolysis device (electrochemical reaction device) such as a carbon dioxide electrolysis device for reducing the cathode of the carbon dioxide (CO2) produced from a power station or a garbage disposal station and oxidizing water (H2O) at the anode. In the cathode, for example, carbon dioxide is reduced to generate carbon compounds such as carbon monoxide (CO). In the case of realizing such an electrolysis device by a battery method (also referred to as an electrolysis cell), it is effective to realize it by means of a fuel cell such as a polymer electric fuel cell (Polymer Electric Fuel Cell (PEFC)). By directly supplying carbon dioxide to the catalyst layer of the cathode, the reduction reaction of carbon dioxide can be rapidly advanced. And then, by forming a battery stack by stacking electrolysis cells, it is possible to save space and enable the reduction reaction to proceed efficiently. Summary of the Invention

[0005] An object of the present invention is to diagnose or predict the state of an electrolysis device with high accuracy.

[0006] A state diagnosis system according to an embodiment is a state diagnosis system for diagnosing the state of an electrolysis device. The electrolysis device includes an electrolysis cell. The electrolysis cell includes an anode, a cathode, and a separator separating the anode and the cathode. The state diagnosis system comprises: an impedance measuring device for measuring the complex impedance of the electrolysis device after the operation of the electrolysis device starts, and outputting data indicating the measurement result of the complex impedance; a first storage unit for storing data including at least one piece of prior information acquired before the operation of the electrolysis device starts, the data including data indicating a correspondence between state information of the electrolysis device and a diagnosis result of the state of the electrolysis device; a first processing unit for 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 indicating that data in the frequency domain of at least a portion of the measurement result is valid; a second processing unit for outputting data indicating the state information based on at least one piece of first data including the data indicating the analysis result; a second storage unit for storing at least one piece of second data including the data indicating the state information; and a third processing unit for diagnosing the state of the electrolysis device based on a plurality of data including the at least one piece of prior information from the first storage unit and the at least one piece of second data from the second storage unit, and outputting data indicating the diagnosis result of the state. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a schematic diagram showing a configuration example of the state diagnosis system and the electrolysis system according to the first embodiment.

[0008] Figure 2 It is a schematic diagram showing a first configuration example of the electrolysis device 10 .

[0009] Figure 3 It is a schematic diagram showing a second configuration example of the electrolysis device 10 .

[0010] Figure 4 3 is a flowchart showing an example of analysis processing executed by the processing unit 31 .

[0011] Figure 5 1 is a diagram showing an example of the complex impedance measurement results of the electrolysis device 10 .

[0012] Figure 6 It is a schematic diagram of a graph showing the results of the Lin-KK Test.

[0013] Figure 7 This is an example of the result when a spectrum in the frequency domain (1000 Hz or less) with a residual error within ±5% is extracted and DRT analysis is performed.

[0014] Figure 8This is a schematic diagram showing an example of the results of extracting and analyzing a frequency spectrum in a frequency domain (500 Hz or less) where the residual error is within ±3%.

[0015] Figure 9 1 is a diagram showing another example of the complex impedance measurement results of the electrolysis device 10 .

[0016] Figure 10 It is a schematic diagram showing a configuration example of a status diagnosis system and an electrolysis system according to a second embodiment.

[0017] Figure 11 It is a schematic diagram showing a configuration example of a status diagnosis system and an electrolysis system according to a third embodiment.

[0018] (Explanation of Symbols)

[0019] 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: Amperemeter; 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: Storage unit; 42: Storage unit; 43: Storage unit; 50: Power supply; 60: Cathode supply source; 70: Anode supply source; 100: Electrolysis cell; 101: Electrolysis cell structure; 130: Support plate; 140: Cathode flow path; 150: Anode flow path; MEA: Membrane electrode assembly. DETAILED DESCRIPTION

[0020] The following describes an electrolysis device according to an embodiment with reference to the accompanying drawings. In the various embodiments described below, substantially identical components may be assigned the same reference numerals, and their descriptions may be partially omitted. The accompanying drawings are schematic, and the relationship between thickness and planar dimensions, the ratio of thickness of various components, and other aspects may differ from reality.

[0021] In this specification, “connected” includes not only direct connection but also indirect connection unless otherwise specified. Furthermore, in this specification, “connected” includes not only physical connection but also electrical connection unless otherwise specified.

[0022] (First embodiment)

[0023] Figure 1 It is a schematic diagram showing a configuration example of the state diagnosis system and the electrolysis system according to the first embodiment. Figure 1The following illustrates an example configuration of an electrolysis system 1. The electrolysis system 1 includes an electrolysis device 10, a measuring unit 23, an impedance measuring device 21, an ammeter 22, processing units 31, 32, 33, a storage unit 41, and a storage unit 42. Components of the electrolysis system 1 other than the electrolysis device 10 can constitute a status diagnostic system for the electrolysis device 10. Examples of the status diagnostic system include a deterioration diagnostic system for the electrolysis device 10.

[0024] Figure 2 This is a schematic diagram illustrating a first structural example of an electrolysis device 10. The electrolysis device 10 includes an electrolysis cell 100. The electrolysis cell 100 includes a cathode 11, an anode 12, a diaphragm (separator) 13, a cathode flow path plate 14 having a cathode flow path 140, and an anode flow path plate 15 having an anode flow path 150. The cathode 11, anode 12, and diaphragm 13 may be stacked to form a membrane electrode assembly (MEA). The membrane electrode assembly (MEA) may also be supported by a support plate 130. The support plate 130 is preferably formed of, for example, an insulating material.

[0025] Figure 3 Schematic diagram showing a second structural example of the electrolysis device 10. The electrolysis device 10 may also be as follows Figure 3 As shown, there are a plurality of electrolytic cells 100. The plurality of electrolytic cells 100 are stacked, for example, with insulating layers 18 interposed therebetween to form an electrolytic cell structure 101 such as a cell stack. The stacked electrolytic cells 100 may be sandwiched between a pair of support plates and further fastened with screws or the like. Figure 3 Two electrolytic cells 100 are shown, but the number of electrolytic cells 100 may be more than two and is not limited to Figure 3 Quantity shown.

[0026] The cathode 11 is, for example, an electrode (reduction electrode) for causing a reduction reaction of at least one reduction object (substance to be reduced) to generate at least one reduction product. The cathode 11 is in contact with the diaphragm 13. Examples of the at least one reduction object 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 (CH4), ethane (C2H6), etc. The reduction reaction in the cathode 11 may also include a side reaction of generating hydrogen (H2) by a reduction reaction of water. In addition, the reduction reaction in the cathode 11 may also include a side reaction of generating water (H2O) by a reduction reaction of oxygen together with the reduction reaction of carbon dioxide.

[0027] The cathode 11 is supplied with cathode fluid from the cathode flow path 140, and is supplied with anode fluid and ions from the diaphragm 13. The cathode fluid contains a gas of a reduction object. The cathode 11 may also have a gas diffusion layer and a cathode catalyst layer provided on the gas diffusion layer. The cathode 11 may also 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 arranged on the cathode flow path 140 side, and the cathode catalyst layer is arranged on the diaphragm 13 side. The cathode catalyst layer may also be inserted into the gas diffusion layer. The cathode catalyst layer preferably has catalyst nanoparticles, catalyst nanostructures, etc. The gas diffusion layer may also be composed of, for example, carbon paper, carbon fiber cloth, etc., and subjected to waterproofing treatment. The porous layer is composed of a porous body having a pore size smaller than that of the carbon paper or carbon fiber cloth.

[0028] By appropriately water-repelling the gas diffusion layer, carbon dioxide gas reaches the cathode catalyst layer primarily 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 after it has entered the gas diffusion layer.

[0029] The cathode catalyst layer preferably includes a catalyst material (cathode catalyst material) capable of reducing the overvoltage of the above-mentioned reduction reaction. The example of such a material, for example, includes 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), tin (Sn) and other metals, metal materials such as alloys, intermetallic compounds, carbon (C), graphene, CNT (carbon nanotubes), fullerenes, the carbon materials such as Ketjen black, Ru complexes, Re complexes and other metal complexes. In the cathode catalyst layer, various shapes such as plate-like, mesh-like, wire-like, particle-like, porous, film-like, island-like can be applied.

[0030] The cathode catalyst material constituting the cathode catalyst layer preferably comprises nanoparticles, nanostructures, or nanowires of the aforementioned metal material, or a composite of nanoparticles of the aforementioned metal material supported on a carbon material such as carbon particles, carbon nanotubes, or graphene. By using catalyst nanoparticles, catalyst nanostructures, catalyst nanowires, or catalyst nanosupport structures as the cathode catalyst material, the efficiency of the carbon dioxide reduction reaction in the cathode 11 can be improved.

[0031] The anode 12 is, for example, an electrode (oxidation electrode) for generating an oxidation reaction of at least one oxidation target (substance to be oxidized) to generate 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 and hydrogen ions. It is also possible to generate oxygen (O2) and hydrogen ions (H2O) by utilizing the oxidation reaction of the anode 12, for example, by oxidizing water (H2O) contained in the anode solution of the anode fluid. + ), or by the reduction reaction of carbon dioxide in the cathode 11 to generate hydroxide ions (OH - ) is oxidized to generate oxygen and water. The anode 12 is provided between the diaphragm 13 and the anode flow path 150 and is in contact with them.

[0032] The anode 12 preferably includes a catalyst material (anode catalyst material) that can reduce the overvoltage of the oxidation reaction. Such catalyst materials include, for example, metals such as platinum (Pt), palladium (Pd), and nickel (Ni), alloys containing these metals, intermetallic compounds, 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.

[0033] The anode 12 has a structure that enables liquid and ions to move between the diaphragm 13 and the anode flow path 150, such as a substrate with a porous structure such as a mesh material, a perforated material, a porous body, a metal fiber sintered body, etc. The substrate can also be composed of metal materials such as titanium (Ti), nickel (Ni), iron (Fe), alloys containing at least one of these metals (such as SUS), etc., and can also be composed of the above-mentioned anode catalyst material. When an oxide is used as the anode catalyst material, it is preferred to attach or stack the anode catalyst material on the surface of the substrate composed of the above-mentioned metal material to form a catalyst layer. In order to improve the oxidation reaction, the anode catalyst material preferably has nanoparticles, nanostructures, nanowires, etc. Nanostructures refer to structures with nano-scale concave and convex structures formed on the surface of the catalyst material. In addition, the oxidation catalyst does not necessarily have to be provided at the anode 12. The oxidation catalyst layer provided outside the anode 12 can also be electrically connected to the anode 12.

[0034] The diaphragm 13 is provided between the cathode 11 and the anode 12. The diaphragm 13 is configured to separate the cathode 11 and the anode 12. The diaphragm 13 includes an ion exchange membrane that can move ions between the cathode 11 and the anode 12 and can separate the cathode 11 and the anode 12. Examples of ion exchange membranes include cation exchange membranes such as Nafion and Flemion, and anion exchange membranes such as Neoceptor, Selemion, and Sustainion. An alkaline solution is used as the electrolyte, and OH is mainly assumed. - In the case of the movement of ions, the diaphragm 13 is preferably composed of an anion exchange membrane. In addition, a membrane with hydrocarbon as the basic skeleton or a membrane with an amine group can also be used to constitute the ion exchange membrane. However, in addition to the ion exchange membrane, as long as it is a material that can allow ions to move between the cathode 11 and the anode 12, a salt bridge, a glass filter, a porous polymer membrane, a porous insulating material, etc. can also be used for the diaphragm 13. However, when the circulation of gas is caused between the cathode 11 and the anode 12, a cyclic reaction is sometimes caused by the reoxidation of the reduction product. Therefore, the exchange of gas between the cathode 11 and the anode 12 is preferably small. Therefore, care should be taken when using a porous film as the diaphragm 13.

[0035] The cathode flow path plate 14 has a cathode flow path 140. The cathode flow path 140 faces the cathode 11. A cathode fluid supplied to the cathode 11 and containing a reduction object can flow through the cathode flow path 140. The cathode fluid may also contain water vapor by humidification. The reduction product is discharged from the cathode flow path 140 mainly contained in the cathode fluid. The type of reduction product varies depending on the type of reduction catalyst, etc. Together with such gas products, water condensed from steam or steam contained in humidified carbon dioxide gas is discharged from the cathode flow path 140. In the electrolytic cell structure 101, when the spaces (such as through holes such as vias) through which the cathode fluid flows are connected in series between multiple electrolytic cells 100, the cathode fluid discharged from one cathode flow path 140 of the multiple electrolytic cells 100 can also be introduced as is into the inlet of the cathode flow path 140 of the adjacent electrolytic cell.

[0036] The types of reduction products also vary depending on the composition of the cathode fluid. When the cathode fluid contains carbon dioxide gas or humidified carbon dioxide gas, the main reduction products produced are carbon monoxide gas and hydrogen as a byproduct. When the cathode fluid contains nitrogen gas, the main reduction products produced are ammonia. When the cathode fluid contains impurity gases such as oxygen, the oxygen is reduced to produce water as a reduction product.

[0037] The cathode flow path 140 is provided on the surface of the cathode flow path plate 14. The cathode flow path plate 14 has a groove (recess) on the surface that forms the cathode flow path 140. The cathode flow path plate 14 is preferably formed using a material with low chemical reactivity and high conductivity. Examples of such materials include metal materials such as titanium (Ti) and SUS, carbon, etc. In addition, the material of the flow path plate includes, for example, a material with low chemical reactivity and no conductivity. Examples of such materials include, for example, insulating resin materials such as acrylic resin, polyetheretherketone (PEEK), and fluororesin. In addition, the cathode flow path plate 14 has screw holes for fastening. In addition, a seal may be sandwiched between the front and back of each cathode flow path plate 14 as needed. In addition, the cathode flow path 140 may also be provided on the cathode current collector 16.

[0038] The cathode flow path 140 has an inlet and an outlet. The cathode fluid is supplied from the cathode supply source 60 through the inlet, and the cathode fluid containing the reduction product is discharged through the outlet. The cathode fluid flows through the cathode flow path 140 in contact with the cathode 11. The cathode fluid discharged from the cathode flow path 140 may also contain unreacted reduction products, etc.

[0039] The cathode flow path plate 14 may also have a pad connected to the cathode 11 for electrical connection to the cathode 11. The shape of the cathode flow path 140 is not particularly limited as long as it is continuously connected. For example, a curved structure formed by bending a long and narrow flow path can be used. This allows the cathode fluid to flow evenly across the surface of the cathode 11, thereby achieving a uniform reaction in the cathode 11, which is preferred.

[0040] The cathode fluid can also 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 may not be 100%. It is also possible to use a fluid containing carbon dioxide gas discharged from various facilities as the cathode fluid. In this case, the cathode fluid may also contain impurity gases. When the first gas contained in the cathode fluid is carbon dioxide gas, the second gas contained in the cathode fluid is, for example, 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, for example, preferably greater than 1 ppm and less than 100,000 ppm.

[0041] The cathode channel plate 14 is mainly formed of a single member, but may also be formed of a plurality of different members stacked together. Furthermore, a hydrophilic or water-repellent function may be imparted by subjecting a portion or the entire surface of the plate to surface treatment.

[0042] The anode flow path plate 15 has an anode flow path 150. The anode flow path 150 faces the anode 12. The anode fluid supplied to the anode 12 can flow through the anode flow path 150. The anode fluid includes, for example, a liquid such as an anode solution.

[0043] The anode solution preferably contains at least water (H 2 O). For example, when the reduction target is carbon dioxide, carbon dioxide is supplied from the cathode flow path 140 , so the anode solution may or may not contain carbon dioxide.

[0044] As the anode solution, an aqueous solution (electrolyte) containing metal ions can be used. As the aqueous solution, for example, a solution containing phosphate ions (PO4 2- ), borate ion (BO3 3- ), sodium ion (Na + ), potassium ion (K + ), calcium ions (Ca 2+ ), lithium ion (Li + ), cesium ions (Cs + ), magnesium ions (Mg 2+ ), chloride ion (Cl - ), bicarbonate ion (HCO3 - ) etc. In addition, aqueous solutions containing lithium bicarbonate (LiHCO 3 ), sodium bicarbonate (NaHCO 3 ), potassium bicarbonate (KHCO 3 ), cesium bicarbonate (CsHCO 3 ), phosphoric acid, boric acid, etc. can also be used.

[0045] The anode flow path 150 is provided on the surface of the anode flow path plate 15. The anode flow path plate 15 is used to supply the anode fluid to the anode 12, and has a groove (recess) on the surface that forms the anode flow path 150. The anode flow path plate 15 is preferably formed using a material with low chemical reactivity and high electrical conductivity. Examples of such materials include metal materials such as Ti and SUS, carbon, etc. In addition, the anode flow path 150 can also be provided on the anode current collector 17. In addition, the material of the anode flow path plate 15 includes, for example, a material with low chemical reactivity and no electrical conductivity. Examples of such materials include, for example, insulating resin materials such as acrylic resin, polyetheretherketone (PEEK), and fluororesin. In addition, the anode flow path plate 15 has screw holes for fastening that are not shown in the figure.

[0046] The anode channel plate 15 is mainly formed of a single member, but may be formed of a plurality of different members stacked together. Furthermore, a hydrophilic or water-repellent function may be imparted by subjecting a portion or the entire surface of the plate to surface treatment.

[0047] The anode flow path 150 has an inlet and an outlet. The anode fluid is supplied from the anode supply source 70 through the inlet and discharged through the outlet. The anode fluid flows through the anode flow path 150 in contact with the anode 12. The anode fluid discharged from the anode flow path 150 may also contain unreacted oxidized substances, electrolyte, oxidation products, etc.

[0048] The anode flow path plate 15 may also have a pad connected to the anode 12 for electrical connection to the anode 12. The shape of the anode flow path 150 is not particularly limited as long as it is continuously connected. For example, a curved structure formed by bending a long and narrow flow path can be used. This allows the anode fluid to flow uniformly on the surface of the anode 12, so a uniform reaction can be carried out in the anode 12, which is preferred.

[0049] Cathode current collector 16 is electrically connected to cathode 11. Cathode current collector 16 is in contact with the surface of cathode channel plate 14 opposite to cathode channel 140. Cathode current collector 16 is preferably made of a material with low chemical reactivity and high electrical conductivity. Examples of such materials include metal materials such as Ti and SUS, and carbon.

[0050] Anode current collector 17 is electrically connected to anode 12. Anode current collector 17 is in contact with the surface of anode flow path plate 15 opposite to anode flow path 150. Anode current collector 17 is preferably made of a material with low chemical reactivity and high electrical conductivity. Examples of such materials include metal materials such as Ti and SUS, and carbon.

[0051] The insulating layer 18 is provided between the two electrolytic cells 100. The insulating layer 18 is formed using, for example, a material coated with a fluororesin such as silicone or polytetrafluoroethylene (PTFE), an insulating resin material such as acrylic resin, polyetheretherketone (PEEK), or a fluororesin. The electrolysis device 10 may include a plurality of insulating layers 18.

[0052] The electrolysis device 10 can also be Figure 3 As shown, there is a reference electrode 19. The reference electrode 19 is, for example, arranged between a plurality of electrolytic cells 100. The reference electrode 19 can also be as Figure 3 As shown, it is disposed between a plurality of insulating layers 18. The reference electrode 19 may be connected to the impedance measuring device 21 via wiring, for example. The reference electrode 19 may be formed using, for example, a material that can be used for the cathode current collector 16 and the anode current collector 17. The electrolysis device 10 may not have the reference electrode 19.

[0053] The electrolytic cell 100 may also be connected to a cathode supply source 60. The cathode supply source 60 can, for example, supply a cathode fluid to the electrolytic cell 100. The cathode supply source 60 is connected to the inlet of the cathode flow path 140 of the electrolytic cell 100 via piping, for example. The cathode supply source 60 is provided inside or outside the status diagnosis system or the electrolysis system 1.

[0054] The electrolytic cell 100 may also be connected to an anode supply source 70. The anode supply source 70 can, for example, supply an anode fluid to the electrolytic cell 100. The anode supply source 70 is connected to the inlet of the anode flow path 150 of the electrolytic cell 100 via piping, for example. The anode supply source 70 is provided inside or outside the status diagnosis system or the electrolysis system 1.

[0055] The electrolytic cell 100 may also be connected to a power supply 50. The power supply 50 may, for example, supply current or voltage to the electrolytic cell 100. The power supply 50 may also supply AC voltage and DC voltage. A power supply that supplies a DC component or an AC component may also be built into the power supply 50. Alternatively, the power supply 50 may be two independent power supplies, with one supplying an AC component and the other supplying a DC component. The power supply 50 may be electrically connected to the cathode current collector 16, for example, via wiring. Multiple cathode current collectors 16 may also be electrically connected in parallel to each other. The power supply 50 may be electrically connected to the anode current collector 17, for example, via wiring. Multiple anode current collectors 17 may also be electrically connected in parallel to each other. The power supply 50 is provided inside or outside the status diagnosis system or the electrolysis system 1.

[0056] Examples of the power source 50 are not limited to conventional system power sources or batteries; they may also include power sources that supply electricity generated by renewable energy sources such as solar cells and wind power. When using renewable energy, efficient utilization of the reduction target is also environmentally preferable. The power source 50 may also 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. Furthermore, the power source 50 may be located external to the electrolysis device 10. By controlling the current or voltage supplied to the electrolysis cells 100, the power source 50 can achieve optimal operation of the electrolysis cells 100 and improve the reaction efficiency of the reduction reaction of the reduction target in the cathode 11. Furthermore, by adjusting the current or voltage supplied to each electrolysis cell 100, optimal operation of the electrolysis cells 100 can be achieved, improving the reaction efficiency of the reduction reaction of the reduction target in the cathode 11. An element for monitoring current, such as a resistor, may be provided between the power source 50 and the electrolysis cells 100 or the electrolysis cell structure 101. This makes it possible to control the voltage to achieve optimal operation of the electrolytic cell 100 and improve the reaction efficiency of the reduction reaction in the cathode 11 .

[0057] Next, an example of an operation method of the electrolysis device 10 will be described. Here, the case where carbon monoxide is generated as a carbon compound will be mainly described, but the reduction product of carbon dioxide is not limited to a carbon compound.

[0058] First, the process of oxidizing water (H2O) to generate hydrogen ions (H + ) is a reaction process under the condition of. When cathode fluid is supplied from cathode supply source 60 to cathode flow path 140, anode fluid is supplied from anode supply source 70 to anode flow path 150, and current is supplied between cathode 11 and anode 12 from power supply 50, an oxidation reaction of water (H2O) occurs in anode 12 in contact with the anode solution. Specifically, as shown in the following formula (1), H2O contained in the anode solution is oxidized to generate oxygen (O2) and hydrogen ions (H + ).

[0059] 2H2O→4H + +O2+4e - …(1)

[0060] H generated in the anode 12 + The electrons (e) are moved through the electrolyte in the anode flow path 150 and the separator 13 and reach the vicinity of the cathode 11. - ) and H moved to the vicinity of the cathode 11 + , a carbon dioxide reduction reaction occurs. Specifically, as shown in the following formula (2), carbon dioxide supplied from the cathode flow path 140 to the cathode 11 is reduced to produce carbon monoxide. In addition, hydrogen ions accept electrons as shown in the following formula (3), producing hydrogen. In this case, hydrogen can also be produced simultaneously with carbon monoxide.

[0061] CO2+2H + +2e - →CO+H2O…(2)

[0062] 2H + +2e - →H2…(3)

[0063] Next, the process of reducing carbon dioxide (CO2) to generate hydroxide ions (OH - ) is the reaction process under the condition of. When current is supplied between the cathode 11 and the anode 12 from the power supply, water (H2O) and carbon dioxide (CO2) are reduced near the cathode 11 as shown in the following formula (4), and carbon monoxide (CO) and hydroxide ions (OH - ). In addition, water accepts electrons as shown in the following formula (5) to generate hydrogen. In this case, hydrogen can also be generated simultaneously with carbon monoxide. The hydroxide ions (OH - ) diffuses to the vicinity of the anode 12, as shown in the following formula (6), the hydroxide ions (OH - ) is oxidized to produce oxygen (O2).

[0064] 2CO2+2H2O+4e - →2CO+4OH - …(4)

[0065] 2H2O+2e - →H2+2OH - …(5)

[0066] 4OH - →2H2O+O2+4e - …(6)

[0067] In this way, the electrolytic cell 100 is not only used exclusively for reducing carbon dioxide, but can also produce a reduction product and hydrogen in an arbitrary ratio, such as producing carbon monoxide and hydrogen at a ratio of 1:2, and producing methanol in a subsequent chemical reaction.

[0068] Hydrogen is a raw material that is easily obtained cheaply from the electrolysis of water or fossil fuels, so the ratio of hydrogen does not need to be large. Based on these viewpoints, the ratio of carbon monoxide to hydrogen is preferably at least 1, and more preferably 1.5 or more based on economic and environmental considerations.

[0069] Next, the reaction process in which oxygen (O2) is mainly reduced to produce water (H2O) will be described. When current is supplied between the cathode 11 and the anode 12 from a power supply, oxygen (O2) is reduced near the cathode 11 as shown in the following formula (7), and water (H2O) is produced. At this time, although water can also be produced simultaneously with carbon monoxide and hydrogen, it is believed that due to the difference in reduction potential, the reduction of oxygen mainly proceeds. As shown in the following formula (8), the water in the electrolyte is oxidized to produce oxygen (O2) and protons (H + ), the protons (H + ) diffuses from the vicinity of the anode 12. In addition, hydrogen peroxide (H2O2) may also be generated as an intermediate product or product. In addition, regarding the oxygen reduction reaction, 2-electron reduction and 4-electron reduction are considered, which may occur in any acidic or alkaline environment.

[0070] O2+4H + +4e - →2H2O…(7)

[0071] 2H2O→O2+4H + +4e - …(8)

[0072] Such an electrolytic cell 100 is not only used exclusively for reducing carbon dioxide, but can also reduce carbon dioxide even if impurity gases such as oxygen and nitrogen are mixed therein.

[0073] In the case of a nitrogen electrolysis device, ammonia can be generated by reducing nitrogen at the cathode 11. The structure of the electrolysis device 10 can be appropriately adopted for other structures of the nitrogen electrolysis device.

[0074] The impedance measuring device 21 measures the complex impedance of the electrolytic cell 100 in the electrolytic device 10. For example, the complex impedance is measured before or after the electrolytic device 10 begins operating. The impedance measuring device 21 modulates at least one of a current and a voltage and supplies it between the cathode 11 and anode 12 of the electrolytic cell 100. The impedance measuring device 21 can obtain data representing the complex impedance from at least one value of the modulated current or voltage and at least one value of the voltage response or current response of the electrolytic cell 100 or the electrolytic cell structure 101. Furthermore, modulation means varying the value of an object over time, including periodically varying the value of an object. The impedance measuring device 21 can also obtain data representing the complex impedance by supplying at least one of an alternating current and an alternating voltage between the cathode 11 and anode 12 of the electrolytic cell 100. The complex impedance measurement results can also include at least one signal or multiple signals selected from the group consisting of a direct current, a sine wave, a rectangular wave, a triangular wave, a pulse, and noise. For example, the complex impedance may be measured at a plurality of times during a predetermined period of 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.

[0075] When impedance measurement is 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 anode 12. In this case, the complex impedance value can be obtained by measuring the current / voltage at the cathode 11 and anode 12, as well as at other measurement terminals connected to the impedance measuring device 21, extracting the AC component, and dividing the input voltage / current. Alternatively, the power supply 50 may supply a voltage / current obtained by superimposing the DC voltage / current component used for electrolysis and the AC voltage / current component used for impedance measurement between the cathode 11 and anode 12. In this case, setting information such as the frequency and amplitude of the AC component is transmitted from the impedance measuring device 21 to the power supply 50 as a signal. In this case, the complex impedance value can be obtained by measuring the current / voltage at the cathode 11 and anode 12, as well as at other measurement terminals connected to the impedance measuring device 21, extracting the AC component, and dividing the input voltage / current.

[0076] The impedance measuring device 21 is provided independently of the power supply 50. The impedance measuring device 21 is connected in parallel or in series with the power supply 50. The impedance measuring device 21 may also be electrically connected to the wiring between the electrolysis device 10 and the power supply 50. Even if the impedance measuring device 21 is not connected to the wiring between the electrolysis device 10 and the power supply 50, it is still possible to obtain similar complex impedance measurement results by utilizing the effects of induced electromotive force such as electromagnetic induction.

[0077] The complex impedance measurement result may include a scalar value or a vector value consisting of the modulation frequency and the real and imaginary parts of the impedance.

[0078] Data indicating the measurement result 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.

[0079] The ammeter 22 is, for example, built into the power supply 50 and outputs the actual supplied current value relative to the set constant current value. The ammeter 22 may also be provided, for example, in the middle of 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 also be provided in the measuring unit 23.

[0080] Processing unit 31 analyzes the data representing the complex impedance measurement results, determines the validity of the analysis results, and outputs data representing the analysis results indicating that at least a portion of the frequency domain data of the measurement results is valid. The data representing the analysis results is output from processing unit 31 and input to processing unit 32.

[0081] The storage unit 41 stores at least one piece of prior information. The storage unit 41 is composed of, for example, a storage device including a database. The data stored in the storage unit 41 is preferably non-rewritable.

[0082] Prior information includes data obtained before the electrolysis device 10 begins operating, indicating the correspondence between status information of the electrolysis device 10 and status diagnosis results of the electrolysis device 10. Status diagnosis results include degradation diagnosis results. Degradation diagnosis results indicate the main causes of degradation at various times in the operating electrolysis device 10. Status information includes, for example, impedance information, operating information data, and information on temporal changes such as their time derivatives.

[0083] The impedance information includes information indicating the analysis results of the complex impedance measurement results and information indicating the validity of the analysis of the complex impedance measurement results. The information indicating the validity of the analysis includes, for example, information indicating whether the analysis results at each time point during the operation of the electrolysis device 10 are valid or invalid, information on the duration of each valid and invalid state, and information on residuals obtained through fitting using the Lin-KK test, which will be described later.

[0084] The operating information includes at least one parameter indicating the operating state of the electrolysis device 10. The operating information can be acquired by the measuring unit 23. The measuring unit 23 may include at least one detector capable of measuring a parameter related to the electrolysis device 10 that is different from the parameter measured by the impedance measuring device 21 or the ammeter 22.

[0085] Examples of parameters that can be measured using at least one detector include the cell voltage of the electrolysis device 10, the cell temperature of the electrolysis device 10, the temperature of the cathode fluid, the temperature of the anode fluid, the temperature of the cathode fluid flowing into the inlet of the cathode flow path 140, the temperature of the cathode fluid flowing out of the outlet of the cathode flow path 140, the temperature of the anode fluid flowing into the inlet of the anode flow path 150, the temperature of the anode fluid flowing out of the outlet of the anode flow path 150, the flow rate of the cathode fluid, the flow rate of the anode fluid, the composition of the cathode fluid, the composition of the anode fluid, the Faraday efficiency of the oxidation product, the Faraday efficiency of the reduction product, the concentration of the electrolyte contained in the anode fluid, the pressure of the cathode flow path 140, the pressure of the anode flow path 150, the inlet pressure of the cathode flow path 140, the outlet pressure of the cathode flow path 140, the inlet pressure of the anode flow path 150, the outlet pressure of the anode flow path 150, the dew point of the cathode fluid, the pressure loss of the cathode flow path 140, the pressure loss of the anode flow path 150, the potential of the cathode 11, the potential of the anode 12, the potential of the reference electrode 19, etc. The data indicating these parameters are output from the measuring unit 23 and input to the storage unit 41 to be stored.

[0086] The processing unit 32 outputs data representing status information of the electrolysis device 10 based on at least one first data including data representing analysis results of complex impedance measurement results. The data representing status information of the electrolysis device 10 is output from the processing unit 32 and input into the storage unit 42. The at least one first data may also include data representing a parameter measured by at least one detector of the measurement unit 23.

[0087] 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 also store at least one of data output from the processing unit 31 and data output from the processing unit 32. For example, it is preferable to update and add data stored in the storage unit 42 while the electrolysis device 10 is in operation. The storage unit 42 is constituted, for example, by a storage device including a database.

[0088] The storage unit 41 may also store at least one piece of prior information about an electrolysis device 10 different from the currently operating electrolysis device 10. 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 state diagnosis, such as degradation diagnosis, and state prediction, such as degradation prediction, of the electrolysis device 10. This allows for highly accurate diagnosis of the current state of the electrolysis device 10 and prediction of its future state.

[0089] Processing unit 33 reads at least one piece of prior information data from storage unit 41 and at least one piece of second data from storage unit 42. Based on a plurality of data including the at least one piece of prior information data from storage unit 41 and the at least one piece of second data from storage unit 42, processing unit 33 diagnoses the condition of electrolysis device 10 and outputs data indicating the diagnosis result. The diagnosis result includes, for example, a diagnosis result of degradation of electrolysis device 10.

[0090] The processing units 31, 32, and 33 may be configured using hardware such as a processor. Alternatively, each action may be stored as an action program in a computer-readable recording medium such as a memory, and each action may be executed by appropriately reading the action program stored in the recording medium using hardware.

[0091] The processing units 31, 32, and 33 may include personal computers, servers, edge devices, and the like, and may be appropriately selected depending on the installation location of the electrolysis apparatus 10. Each processing unit is preferably capable of communicating via a Universal Serial Bus (USB) cable, a Local Area Network (LAN) cable, or the like in accordance with a communication standard.

[0092] The processing units 31, 32, and 33 may be integrally configured using a single processor or may be separately configured using a plurality of different processors. A series of processes may be processed by a single processor or by a plurality of independent processors.

[0093] As described above, the state diagnosis system and electrolysis system of the first embodiment can diagnose the state of the electrolysis device 10 based on the complex impedance measurement results at each time point and the operating information of the electrolysis device 10. In this case, by referring to the prior information stored in the storage unit 41, the state of the electrolysis device 10 can be diagnosed with high accuracy. Furthermore, by referring to the electrolysis device state information stored in the storage unit 42, the state 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.

[0094] Here, an example of complex impedance analysis processing 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 use the processing unit 31 to determine the analytical validity and analytical validity range of the complex impedance measurement results, distinguish between valid and invalid regions of the analytical results within the valid range, and output data representing the analytical results within the valid range to the processing unit 32 if the analysis is valid.

[0095] Figure 4This is a flowchart illustrating an example of analytical processing performed by the processing unit 31. The processing unit 31 performs fitting using the Lin-KK test on the data representing 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 analytical validity if they satisfy linearity, time invariance, and a causal relationship with the modulation signal. For example, this validity can be determined by fitting the complex impedance / spectrum that depends on the modulation frequency to an equivalent circuit model.

[0096] The equivalent circuit model is used to fit complex impedance / spectral data. It consists of an ohmic resistor, Rohm, and M (M is a natural number) RC elements. Rohm and the resistance components, Rk, of the M RC elements are free parameters for fitting. The real and imaginary parts of the complex impedance of the equivalent circuit model are guaranteed to satisfy the Kramers-Kronig relationship. Therefore, the response signal of the equivalent circuit model to a modulated signal is linear, time-invariant, and causal.

[0097] By fitting the complex impedance spectrum obtained by measuring the complex impedance of the electrolysis device 10 with the complex impedance spectrum of a corresponding appropriate equivalent circuit model, a residual error, which serves as an indicator of the quality of the fit, can be obtained. This is generally known as the Lin-KK test. In addition to the Lin-KK test, other methods for evaluating the validity of complex impedance measurement results can also be used to determine the extent to which the real and imaginary parts of the complex impedance satisfy the Kramers-Kronig relationship to evaluate validity.

[0098] Since the residual is calculated for the value of the complex impedance in each frequency component, the validity of the measurement result of the complex impedance in each frequency component can be quantitatively evaluated.

[0099] The smaller the residual, the more valid the complex impedance measurement result. For a measurement result that can be determined to be valid, the residual is preferably within ±5%. Furthermore, the residual is more preferably within ±3%.

[0100] Figure 5 An example of the measurement results of the complex impedance of the electrolysis device 10 is shown. Figure 5 This graph shows the frequency characteristics of the real part Re and imaginary part Im of the complex impedance. The horizontal axis of the graph is the frequency of the response signal [Hz]. The vertical axis of the graph is the residual error Δ [%] of the Lin-KK test.

[0101] Create a presentation as follows Figure 5The electrolysis device 10 of complex impedance shown in FIG. The cathode 11 is formed using a laminate formed by coating a catalyst layer on a carbon substrate composed of a gas diffusion layer composed of stacked microporous layers. The anode 12 is formed using a conductive / corrosion-resistant non-woven fabric such as Ti coated with a catalyst such as iridium oxide (IrOx). The diaphragm 13 is formed using a porous membrane. The cathode flow path plate 14 is formed using a Ti plate having a flow path pattern on the surface. The anode flow path plate 15 is formed using a Ti plate having a flow path pattern on the 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.

[0102] The electrolytic cell 100 is formed by stacking a cathode current collector 16, a cathode flow plate 14, a cathode 11, a separator 13, an anode 12, an anode flow plate 15, and an anode current collector 17 in this order. Multiple electrolytic cells 100 are then stacked with an insulating layer 18 and a reference electrode 19 sandwiched between them to form a cell stack. The number of stacked electrolytic cells 100 can be two or more, or even several hundred. The cell stack is sandwiched between support plates and secured with screws.

[0103] The electrolysis device 10 supplies carbon dioxide gas at a flow rate of 33.5 sccm from the cathode supply source 60 to the cathode flow path 140, introduces potassium hydroxide aqueous solution (concentration 1M KOH) at a flow rate of 5 mL / min from the anode supply source 70 to the anode flow path 150, and supplies a current of 400 mA / cm2 between the cathode 11 and the anode 12 from the power supply 50. 2 The current density is used to operate the device.

[0104] For example, under the following measurement conditions, Figure 5 The complex impedance shown. The impedance measuring device 21 is a VSP from Bio-Logic. The frequency range of the superimposed alternating current as a single sinusoidal wave is 0.01 Hz to 1 MHz, and the peak-to-peak amplitude is 5% to 40% relative to the applied current. The measurement mode is the Galvano Electrochemical Impedance Spectroscopy mode. In addition, it is assumed that even if the measurement is not performed in exactly the same manner as the measurement conditions, a result roughly equivalent to the effect described here is obtained. The reference electrode 19 is arranged between a plurality of electrolytic cells 100, and the impedance between the cathode 11, the anode 12, and the reference electrode 19 is measured simultaneously. In addition, the same result can be obtained in the complex impedance measurement results between any electrodes.

[0105] Figure 6 Shows the Figure 5 The graph shows the results of the Lin-KK Test of the complex impedance measurement results. Figure 6 The horizontal axis of the graph represents frequency [Hz]. Figure 5The vertical axis of the graph represents γ[Ω]. Figure 6 As shown in , if the frequency is approximately 1000 Hz or less, the residual error is within ±5%. Furthermore, if the frequency is approximately 500 Hz or less, the residual error is within ±3%. Figure 5 In FIG, both the residual of the real part of the impedance / spectrum and the residual of the imaginary part of the impedance / spectrum are shown, but either the real part or the imaginary part may be used as the evaluation criterion, or both values ​​may be used as the evaluation criterion.

[0106] When the residual exceeds ±5%, a sharp increase in the residual is observed. However, within ±5%, this sharp increase is not observed. Furthermore, within ±3%, the amplitude of the residual is further suppressed. Furthermore, since measurement noise and other factors are essentially unavoidable, the residual will not be 0% unless a theoretical equivalent circuit model is used that does not contain noise. Therefore, a 0% residual is considered to be due to measurement errors, resulting in an inaccurate measurement of the measurement object. Therefore, a lower limit of 0.001% or greater or -0.001% or less eliminates the possibility of such measurement errors, and the complex impedance measurement result can be considered valid and free of measurement errors. However, there is a possibility of obtaining residuals smaller than ±0.001% in several data points within the scanning frequency range. Therefore, if the residual is greater than 0.001% or less than -0.001% in a certain frequency range (for example, a 10 Hz width), the data points with small residuals greater than 0% and less than 0.001% or greater than -0.001% and less than 0% can be considered not invalid.

[0107] Figure 6 The results are shown when characteristic frequency components are extracted by the Distribution of Relaxation Times (DRT) analysis in the entire frequency domain. Figure 6 The results of the analysis using Gaussian Process-Distribution of Relaxation Times (GP-DRT), one of the DRT analysis methods, are shown. Figure 6 In the case of the data shown, Figure 6 The gray area shown in the figure shows a large variance, making it impossible to extract the polarization resistance component. Therefore, effective analysis of the complex impedance measurement results cannot be obtained using this data. γ represents the partial resistance value of each peak component obtained by GP-DRT.

[0108] Next, Figure 7 The following shows an example of the results of extracting the frequency spectrum (below 1000 Hz) with a residual error within ±5% and performing GP-DRT analysis. Figure 7As shown in the gray area of ​​, the variance is greatly reduced, and the spectrum area where the polarization resistance component can be extracted can be extracted. Figure 8 The following shows an example of the results of extracting the frequency spectrum in the frequency domain (500 Hz or less) with a residual error within ±3% and performing GP-DRT analysis. Figure 8 As shown in the gray area of ​​, it can be seen that the variance is greatly reduced, and the spectrum region where the polarization resistance component can be extracted can be extracted.

[0109] like Figure 4 As shown, if the residuals for all of the measured frequency domains are within the specified range (S2: Yes), the measurement results for all of the frequency domains are analyzed as is (S3). If the residuals for all of the measured frequency domains are not within the specified range (S2: No), and further, if the residuals for a portion of the measured frequency domains are within the specified range (S4: Yes), only the measurement results for the frequency domains with residuals within the specified range are analyzed as valid data (S5). If the residuals for all of the measured frequency domains are not within the specified range but are outside the specified range (S4: No), the measurement results cannot be analyzed (unanalyzable). However, in this case, a large residual state is identified, and the time at which the residual occurred is recorded. Furthermore, the complex impedance is measured at multiple subsequent times. If the large residual state persists, it is determined that some deterioration condition is progressing in the electrolysis device 10, and data indicating a diagnosis of abnormality is output from the processing unit 31 (S6). The data indicating the abnormal diagnosis result may be input to a subsequent processing unit such as the processing unit 35 described later and used to control the operating conditions of the electrolysis device 10. Examples of the operating conditions include the current value supplied to the electrolysis device 10.

[0110] Through the analysis process, the processing unit 31 can analyze the time when the analysis becomes effective, the duration of the effective state, and the numeralized degree of effectiveness if the analysis is effective, and analyze the time when the analysis becomes invalid, the duration of the invalid state, and the numeralized degree of invalidity if the analysis is invalid. This makes it possible to distinguish between the effective and invalid regions in the complex impedance measurement results.

[0111] 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 .

[0112] As described above, in the processing unit 31 , by performing fitting using the Lin-KK test and analyzing the measurement results of the complex impedance, the state of the electrolysis device 10 can be diagnosed with high accuracy.

[0113] 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, in general, the complex impedance measurement results will not be judged as valid if they are not in a stable state. Therefore, depending on the degradation pattern of the electrolysis device 10, there is a possibility that the electrolysis device 10 is in an unstable state with a significant progression of degradation, making it difficult to obtain valid complex impedance measurement results.

[0114] Furthermore, in typical analysis processing of complex impedance measurement results, even if a portion of the measurement frequency domain has a valid region, if the remaining region is invalid, the data is determined to be invalid, and thus the data cannot be used to diagnose the condition of the electrolysis device 10. Therefore, in cases where degradation progresses, it is difficult to obtain valid complex impedance measurement results, and further, it is difficult to diagnose the degradation condition in detail.

[0115] Furthermore, even if an invalid complex impedance measurement result is obtained, information indicating the measurement result is not stored and utilized. Therefore, when the degradation state of the electrolysis device 10 progresses, information indicating the persistence of the degradation state is not utilized, making it difficult to predict degradation.

[0116] Furthermore, when diagnosing the state of the electrolysis device 10 while the electrolysis device 10 is not in operation, historical information on degradation is difficult to retain, so information for diagnosing the state of the electrolysis device 10 is insufficient, making it difficult to improve diagnostic accuracy.

[0117] In contrast, in the condition diagnosis system and electrolysis system of the first embodiment, the measurement results of the complex impedance are analyzed. Even if a portion of the measurement frequency is an invalid region, if another portion of the measurement frequency has a valid region, the analysis results of the measurement results in the valid region 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.

[0118] Based on the complex impedance measurement results and the information of the battery obtained in advance, the degradation diagnosis of the conventional carbon dioxide electrolysis cell is performed. Although the effectiveness evaluation of the complex impedance measurement results is performed, only the root mean square error of the residual accumulated within the measurement frequency range is evaluated. Therefore, even if there is a frequency domain with high residuals, it is averaged through the frequency domain with low residuals, and the residual is estimated to be low. Therefore, it is impossible to evaluate the effectiveness of the complex impedance measurement results with the same high accuracy as the first embodiment. Furthermore, in the conventional degradation diagnosis of carbon dioxide electrolysis cells, the battery state is evaluated only based on the root mean square error of the residual accumulated within the measurement frequency range, so the effective range of the measurement frequency domain is not confirmed. From this point of view, it is also believed that the degradation diagnosis accuracy is low and only the tendency of battery performance is presented.

[0119] about Figure 5The complex impedance measurement results shown are due to the high current density (400mA / cm 2 ) The residual error is large when the electrolysis device 10 is operated. In contrast, when the current density is set to 100 mA / cm 2 In addition, with Figure 5 When the electrolysis device 10 is operated under the same conditions as the measurement conditions of the complex impedance measurement results shown in FIG. Figure 9 As shown, the residual error can be reduced. Figure 9 1 is a diagram showing another example of the complex impedance measurement results of the electrolysis device 10. Therefore, by changing the value of the parameter included in the operation information of the electrolysis device 10 according to the residual, it was confirmed that the residual was improved, and thus the battery could be switched to a stable operation.

[0120] (Second embodiment)

[0121] Figure 10 This is a schematic diagram illustrating an example configuration of a state diagnosis system and an electrolysis system according to a second embodiment. The electrolysis system and state diagnosis system according to the second embodiment differ from those 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 appropriately incorporated for other aspects.

[0122] Processing unit 34 predicts the future state of electrolysis device 10 based on at least one third data including data indicating the state diagnosis results from processing unit 33, and generates data indicating the prediction results. The prediction results include the state diagnosis results of electrolysis device 10 after a predetermined period of time has elapsed while the electrolysis device is in operation. The data indicating the prediction results is input from processing unit 34 to processing unit 35.

[0123] Processing unit 35 generates at least one control signal based on the data representing the prediction result from processing unit 34. The at least one control signal is output from processing unit 35 and input into electrolysis device 10. The at least one control signal is a signal for controlling the operating state of electrolysis device 10. Examples of the at least one control signal include parameter values ​​required for controlling electrolysis device 10, such as a control signal for adjusting the current density of the current supplied to electrolysis device 10, a control signal for adjusting the temperature of electrolysis device 10, and a control signal for adjusting the flow rate of cathode fluid supplied to cathode flow path 140. Without limitation, the at least one control signal may also include a control signal for adjusting at least one parameter detectable by measurement unit 23.

[0124] The processing units 34 and 35 may be configured using hardware such as a processor. Alternatively, each action may be stored as an action program in a computer-readable recording medium such as a memory, and each action may be executed by appropriately reading the action program stored in the recording medium using hardware.

[0125] Processing units 34 and 35 may include personal computers, servers, edge devices, etc., and are appropriately selected according to the installation location of electrolysis apparatus 10. Each processing unit is preferably capable of communicating via a USB cable, LAN cable, or other standard communication method.

[0126] Processing units 34 and 35 may be integrally formed with one processor or may be separately formed with a plurality of different processors, along with processing units 31, 32, and 33. A series of processes may be processed by one processor or by a plurality of independent processors.

[0127] As described above, in the second embodiment, the future state of the electrolysis device 10 is predicted with reference to information indicating the current state of the electrolysis device 10. This makes it possible, for example, to accurately predict the degradation of the electrolysis device 10. By understanding the progress of degradation of the electrolysis device 10 in advance and adjusting various operating conditions of the electrolysis device 10 before degradation progresses, it is possible to suppress future degradation of the electrolysis device 10.

[0128] 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 path 140, a control signal for adjusting the flow rate of the anode fluid supplied to the anode flow path 150, a control signal for adjusting the coolant used to cool the electrolysis device 10, a control signal for controlling the pressure of each flow path of the electrolysis device 10, and a control signal for adjusting the concentration of the electrolyte contained in the anode fluid. By supplying these control signals from the processing unit 35 to the electrolysis device 10 to adjust (modulate) various parameters, it is possible to lock in small changes, thereby enabling more accurate diagnosis and prediction of degradation of the electrolysis device 10.

[0129] Furthermore, data indicating the results of the operation simulation of the electrolysis device 10 may be stored as data indicating advance information in the storage unit 41. This can further improve the accuracy of the degradation diagnosis and degradation prediction of the electrolysis device 10.

[0130] Furthermore, the degradation diagnosis results and degradation prediction results indicate the current or future major causes of degradation of the electrolysis device 10. Examples of major causes of degradation 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, flooding due to operation of the electrolysis device 10, salt precipitation due to operation of the electrolysis device 10, poor fastening of the electrolysis cell 100, and electrical short circuiting of the electrolysis cell 100. In the second embodiment, degradation diagnosis and degradation prediction of the electrolysis device 10 can be performed in detail based on these major causes of degradation.

[0131] The processing unit 34 may also perform analysis using a machine learning model of a time series of at least one third data. This allows for more accurate diagnosis and prediction of degradation of the electrolysis device 10.

[0132] The second embodiment can be combined with the first embodiment as appropriate.

[0133] (Third embodiment)

[0134] Figure 11 This is a schematic diagram illustrating an example configuration of a condition diagnosis system and an electrolysis system according to a 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; the description of the second embodiment can be appropriately incorporated for other aspects.

[0135] The sensor 24 can analyze and monitor the fluid in real time by, for example, detecting the composition of the fluid introduced into the electrolysis device 10. Examples of the sensor 24 include a micro-electromechanical systems (MEMS) sensor, a gas chromatograph, and the like. The electrolysis system 1 may also include a plurality of sensors 24. One of the plurality of sensors 24 may be provided, for example, in the middle of 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 plurality of sensors 24 may be provided, for example, in the middle of 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 also be provided in the measuring unit 23. The detection result of the sensor 24 may also change from moment to moment.

[0136] The sensor 25 can analyze and monitor the fluid in real time by, for example, detecting the composition of the fluid discharged from the electrolysis device 10. Examples of the sensor 25 include a MEMS sensor, a gas chromatograph, and the like. The electrolysis system 1 may also include a plurality of sensors 25. One of the plurality of sensors 25 can detect the composition of the cathode fluid discharged from the cathode flow path 140. Another of the plurality of sensors 25 can detect the composition of the anode fluid discharged from the anode flow path 150. The sensor 25 can also be provided in the measuring unit 23. The detection results of the sensor 25 can also change from moment to moment.

[0137] The storage unit 43 stores data representing at least one external information item. Examples of the data representing at least one external information item include data indicating the supply and demand status of renewable energy, data indicating the availability of at least one of the cathode fluid and the anode fluid, data indicating the status of subsequent processes of the electrolysis device 10, and data indicating market information on carbon credits. The storage unit 43 is comprised of, for example, a storage device including a database.

[0138] The supply and demand status of renewable energy is expressed by, for example, the amount of electricity generated by renewable energy.

[0139] For example, the supply possibility of at least one fluid is indicated by the composition and flow rate of the cathode fluid supplied from the cathode supply source 60 and 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.

[0140] The state of the subsequent process is represented by, for example, the conversion efficiency (reaction rate) of the reduction product in a subsequent device connected to the subsequent stage of the electrolysis device 10 and generating a valuable substance such as a compound through a chemical reaction using the reduction product. Examples of chemical reactions include reactions using the Fischer-Tropsch process (FT process).

[0141] Market information on carbon credits is expressed by information on changes in the price paid for carbon dioxide reductions.

[0142] The processing unit 36 ​​formulates an operation plan or maintenance plan for the electrolysis device 10 based on multiple data, including, for example, data indicating analysis results, data indicating diagnosis results, data indicating prediction results, detection results of the components detected by the sensors 24 and 25, and data indicating at least one external information read from the storage unit 43.

[0143] In the case where at least one external information includes market information on carbon credits, by feeding back the operating conditions at the current time point to the electrolysis device 10 , profits in the carbon credit market can be increased.

[0144] 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 improve the conversion efficiency of the reduction product in the subsequent device, for example.

[0145] The processing unit 36 ​​may be configured using hardware such as a processor, etc. Alternatively, 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 appropriately reading the operation program stored in the recording medium using hardware.

[0146] The processing unit 36 ​​includes a personal computer, a server, an edge device, etc., and is appropriately selected according to the installation location of the electrolysis apparatus 10. The processing unit 36 ​​is preferably capable of communicating via a USB cable, a LAN cable, or the like in accordance with a communication standard.

[0147] Processing unit 36 ​​may be integrally formed with one processor or may be formed separately with a plurality of different processors, along with processing units 31, 32, 33, 34, and 35. A series of processes may be processed by one processor or by a plurality of independent processors.

[0148] The processing unit 36 ​​can also formulate an operation plan for the electrolysis apparatus 10 based on the plurality of data inputted above, and output a control signal for controlling the distribution of the cathode fluid supply to the plurality of electrolysis cells 100 in accordance with the operation plan. By controlling the distribution, the load caused by the reduction reaction can be distributed according to the status of each electrolysis cell 100, and, for example, the operation status can be adjusted in synchronization with the status of subsequent processes in the electrolysis apparatus 10.

[0149] The processing unit 36 ​​can also formulate a maintenance plan for the electrolysis device 10 based on the plurality of data inputted above, generate a control signal according to the maintenance plan, and feed it back to the electrolysis device 10. This prevents future degradation of the electrolysis device 10 and maximizes the efficiency of subsequent processes. Furthermore, by performing coordinated control of the electrolysis device 10 and subsequent processes, a highly efficient electrolysis system 1 can be realized.

[0150] The operation plan or maintenance plan is automatically generated, but can also be changed by user input. In addition, there may not be only one operation plan, but multiple operation plans or maintenance plans can be presented to the user, and the user can select the operation plan or maintenance plan that suits his or her needs.

[0151] The storage unit 43 may also store data indicating a maintenance schedule for the electrolysis apparatus 10 nationwide or worldwide. Thus, the processing unit 36 ​​can plan, based on the maintenance schedule read from the storage unit 43, a route that can, for example, deliver replacement parts required for the electrolysis apparatus 10 to the user in the shortest time and distance. This can shorten the waiting time until replacement parts are delivered, and thus reduce the maintenance time required for the electrolysis apparatus 10.

[0152] Furthermore, similarly 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.

[0153] If the electrolysis device 10 is in operation, current degradation diagnosis of the electrolysis device 10 and future degradation prediction of the electrolysis device 10 can be performed based on the analysis results of the complex impedance measurement results.

[0154] If the electrolysis device 10 is stopped (idle), current degradation diagnosis of the electrolysis device 10 can be performed based on the analysis results of the complex impedance measurement results. This allows identification of deteriorated components without disassembling the electrolysis device 10. By performing a refresh operation without disassembling the electrolysis device 10, based on the deteriorated components, their degree of degradation, and their degradation status, it is possible to estimate performance recovery of the electrolysis device 10, thereby extending the life of the electrolysis device 10. Even if disassembly of the electrolysis device 10 is determined to be necessary for recovery, since the components that need replacement can be identified, only those components need to be replaced, which can be expected to enable efficient reuse and recycling of cells and stacks.

[0155] Furthermore, by storing the data of the at least one external information along with the status information of the electrolysis device 10 in the storage unit 43, degradation / abnormality / lifespan predictions can be performed by referring to this information, and, for example, a maintenance plan for the electrolysis device 10 can be automatically prepared. This can reduce the number of maintenance times and improve operating efficiency.

[0156] In addition, the structures of the above-mentioned embodiments can be combined and applied respectively, and a part of them can also be replaced. Although several embodiments of the present invention are described here, these embodiments are illustrative and are not intended to limit the scope of the invention. These embodiments can be implemented in various other ways, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and their variations are included in the scope and gist of the invention, and are also included in the invention described in the claims and their equivalents.

[0157] The above-mentioned embodiments can be summarized as the following technical solutions.

[0158] (Technical Solution 1)

[0159] A status diagnosis system for diagnosing the status of an electrolysis device, wherein:

[0160] The electrolysis device comprises an electrolysis cell,

[0161] The electrolytic cell has an anode, a cathode, and a separator separating the anode and the cathode.

[0162] The status diagnosis system comprises:

[0163] an impedance measuring device for measuring the complex impedance of the electrolysis device and outputting data representing a measurement result of the complex impedance;

[0164] a first storage unit storing data of at least one piece of prior information acquired before the start of operation of the electrolysis device, including data indicating a correspondence relationship between status information of the electrolysis device and a diagnosis result of the status of the electrolysis device;

[0165] a first processing unit that analyzes data representing a measurement result of the complex impedance, determines validity of the analysis result, and outputs data representing the analysis result determined to be valid for at least a portion of frequency domain data of the measurement result;

[0166] a second processing unit that outputs data representing the state information based on at least one first data including data representing the analysis result;

[0167] a second storage unit that stores at least one second data including data representing the state information; and

[0168] The third processing unit diagnoses the state of the electrolysis device based on a plurality of data including the at least one prior information data from the first storage unit and the at least one second data from the second storage unit, and outputs data indicating a diagnosis result of the state.

[0169] (Technical Solution 2)

[0170] According to the status diagnosis system of technical solution 1,

[0171] The first processing unit:

[0172] By means of the analysis, the analytical validity and analytical validity range of the complex impedance measurement result are determined, and the valid region and invalid region of the complex impedance measurement result are distinguished.

[0173] Data representing the analysis result in the valid area is output.

[0174] (Technical Solution 3)

[0175] According to the status diagnosis system of technical solution 1,

[0176] The device further includes 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.

[0177] (Technical Solution 4)

[0178] According to the status diagnosis system described in technical solution 3,

[0179] The first processing unit:

[0180] By means of the analysis, the analytical validity and analytical validity range of the complex impedance measurement result are determined, and the valid area and invalid area of ​​the measurement result are distinguished.

[0181] Data representing the analysis result in the valid area is output.

[0182] (Technical Solution 5)

[0183] An electrolysis system comprising:

[0184] the electrolysis device; and

[0185] The status diagnosis system described in Technical Solution 3,

[0186] The status diagnosis system

[0187] The present invention further includes a fifth processing unit configured to output a control signal for controlling the operating state of the electrolysis device based on the data indicating the prediction result from the fourth processing unit.

[0188] (Technical Solution 6)

[0189] The electrolysis system according to technical solution 5 further comprises:

[0190] a sensor for detecting a composition of at least one fluid supplied to the electrolytic cell and a composition of at least one fluid discharged from the electrolytic cell, and outputting data representing a detection result of the composition;

[0191] a third storage unit storing data representing at least one external information selected from the group consisting of data representing a supply and demand situation of renewable energy, data representing the supply possibility of the at least one fluid, data representing a state of a subsequent process of the electrolysis device, and data representing market information on carbon credits; and

[0192] The sixth processing unit formulates an operation plan for the electrolysis device based on a plurality of data including data indicating the analysis result, data indicating the diagnosis result of the state, data indicating the prediction result, the detection result of the composition, and data indicating the at least one external information.

[0193] (Technical Solution 7)

[0194] The electrolysis system according to technical solution 6, wherein:

[0195] The electrolysis device has a plurality of electrolysis cells.

[0196] The sixth processing unit formulates an operation plan for the electrolysis device based on the plurality of data, and outputs a control signal for controlling the supply amount of the cathode fluid distributed to the plurality of electrolysis cells according to the operation plan.

[0197] (Technical Solution 8)

[0198] The electrolysis system according to technical solution 5 further comprises:

[0199] a sensor for detecting a composition of at least one fluid supplied to the electrolytic cell and a composition of at least one fluid discharged from the electrolytic cell, and outputting data representing a detection result of the composition;

[0200] a third storage unit storing data representing at least one external information selected from the group consisting of data representing a supply and demand situation of renewable energy, data representing the supply possibility of the at least one fluid, data representing a state of a subsequent process of the electrolysis device, and data representing market information on carbon credits; and

[0201] The sixth processing unit formulates a maintenance plan for the electrolysis device based on a plurality of data including data indicating the analysis result, data indicating the diagnosis result of the state, data indicating the prediction result, the detection result of the composition, and data indicating the at least one external information.

[0202] (Technical Solution 9)

[0203] The electrolysis system according to technical solution 8, wherein:

[0204] The third storage unit holds data indicating a maintenance plan for electrolysis equipment nationwide or worldwide.

[0205] The sixth processing unit plans a route that can supply replacement parts required for the electrolysis device in the shortest time and the shortest distance according to the maintenance plan.

[0206] (Technical Solution 10)

[0207] The electrolysis system according to any one of technical solutions 5 to 9, wherein:

[0208] The complex impedance measurement result includes at least one signal selected from the group consisting of a direct current, a sine wave, a rectangular wave, a triangle wave, a pulse, and noise.

[0209] The measurement frequency of the complex impedance is in the range of 0 kHz to 1 GHz.

[0210] (Technical Solution 11)

[0211] The electrolysis system according to any one of technical solutions 5 to 10, wherein:

[0212] The first processing unit performs fitting processing using an equivalent circuit model on data representing the measurement result of the complex impedance, and determines that the measurement result in a region where the calculated residual value is within ±5% is a valid region.

[0213] (Technical Solution 12)

[0214] The electrolysis system according to technical solution 11, wherein:

[0215] The first processing unit determines the measurement result in a region where the residual value is within ±3% as the valid region.

[0216] (Technical Solution 13)

[0217] The electrolysis system according to Technical Solution 6 or Technical Solution 8, wherein:

[0218] The sixth processing unit outputs at least one control signal for controlling at least one of the flow rate of at least one fluid supplied to the electrolysis device, the composition of at least one fluid supplied to the electrolysis device, the temperature of the electrolysis device, and the pressure of the electrolysis device in accordance with the operation plan or the maintenance plan.

[0219] (Technical Solution 14)

[0220] The electrolysis system according to any one of technical solutions 5 to 9, wherein:

[0221] The at least one prior information data also includes at least one selected from a group consisting of data representing operating information of the electrolysis device obtained before the operation of the electrolysis device starts, data representing operating information of a second electrolysis device different from the electrolysis device, and data representing an operation simulation result of the electrolysis device.

[0222] (Technical Solution 15)

[0223] According to the electrolysis system of technical solution 14,

[0224] The operating information includes at least one parameter selected from a group consisting of the temperature of the electrolysis device, the temperature of the cathode fluid supplied to the electrolysis device, the temperature of the anode fluid supplied to the electrolysis device, the flow rate of the cathode fluid, the composition of the cathode fluid, the cell voltage of the electrolysis device, the Faraday efficiency of at least one product generated by the electrolysis device, the electrolyte concentration contained in the anode fluid, the inlet pressure of the cathode flow path facing the cathode, the inlet pressure of the anode flow path facing the anode, the outlet pressure of the cathode flow path, the outlet pressure of the anode flow path, the potential of the reference electrode, the dew point of the cathode fluid, the pressure loss of the cathode flow path, the pressure loss of the anode flow path, the temperature of the anode fluid at the inlet of the anode flow path, and the temperature of the anode fluid at the outlet of the anode flow path.

[0225] (Technical Solution 16)

[0226] According to the electrolysis system of technical solution 14,

[0227] 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 valid range of the analysis, the analysis result, and information on temporal changes therebetween.

[0228] (Technical Solution 17)

[0229] The electrolysis system according to any one of technical solutions 5 to 9, wherein:

[0230] The diagnosis result of the state indicates the main cause of the current deterioration of the electrolysis device.

[0231] The main cause of the degradation includes at least one selected from the group consisting of degradation of the diaphragm, degradation of the cathode catalyst provided at the cathode, degradation of the anode catalyst provided at the anode, overflow due to the operation of the electrolysis device, salt precipitation due to the operation of the electrolysis device, poor fastening of the electrolysis cell, and electrical short circuit of the electrolysis cell.

[0232] (Technical Solution 18)

[0233] The electrolysis system according to any one of technical solutions 5 to 9, wherein:

[0234] The diagnosis result of the state indicates the main cause of future deterioration of the electrolysis device.

[0235] The main cause of the degradation includes at least one selected from the group consisting of degradation of the diaphragm, degradation of the cathode catalyst provided at the cathode, degradation of the anode catalyst provided at the anode, overflow due to the operation of the electrolysis device, salt precipitation due to the operation of the electrolysis device, poor fastening of the electrolysis cell, and electrical short circuit of the electrolysis cell.

[0236] (Technical Solution 19)

[0237] The electrolysis system according to any one of technical solutions 5 to 18, wherein:

[0238] The electrolysis device further includes a reference electrode connected to the impedance measuring device.

[0239] (Technical Solution 20)

[0240] The electrolysis system according to any one of technical solutions 5 to 9, wherein:

[0241] The fourth processing unit predicts a future state of the electrolysis device by analyzing the at least one third data using a time series machine learning model, and outputs data indicating the prediction result.

[0242] (Technical Solution 21)

[0243] The electrolysis system according to any one of technical solutions 5 to 20, wherein:

[0244] The electrolysis device reduces carbon dioxide to produce carbon compounds or reduces nitrogen to produce ammonia.

[0245] (Technical Solution 22)

[0246] A method for diagnosing the status of an electrolysis device, wherein:

[0247] The electrolysis device comprises an electrolysis cell,

[0248] The electrolytic cell has an anode, a cathode, and a separator separating the anode and the cathode.

[0249] In the state diagnosis method,

[0250] measuring the complex impedance of the electrolytic cell using an impedance measuring device, and outputting data representing the measurement result of the complex impedance from the impedance measuring device;

[0251] analyzing data representing the measurement result of the complex impedance by a first processing unit, determining the validity of the analysis result, and outputting data representing the analysis result determined to be valid for at least a portion of the frequency domain data of the measurement result;

[0252] outputting data indicating status information of the electrolysis device based on at least one first data including data indicating the analysis result by a second processing unit,

[0253] Using the third processing unit, at least one piece of prior information obtained before the operation of the electrolysis device starts, including data indicating the correspondence between the status information and the diagnosis result of the status of the electrolysis device, is read from the first storage unit, and at least one second piece of data including data indicating the status information is read from the second storage unit. Based on multiple data including the at least one piece of prior information from the first storage unit and the at least one second piece of data from the second storage unit, the status of the electrolysis device is diagnosed, and data indicating the diagnosis result of the status is output.

Claims

1. A status diagnosis system for diagnosing the status of an electrolysis device, wherein: The electrolysis device comprises an electrolysis cell, The electrolytic cell has an anode, a cathode, and a separator separating the anode and the cathode. The status diagnosis system comprises: an impedance measuring device for measuring the complex impedance of the electrolysis device and outputting data representing a measurement result of the complex impedance; a first storage unit storing data of at least one piece of prior information acquired before the start of operation of the electrolysis device, 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 representing a measurement result of the complex impedance, determines validity of the analysis result, and outputs data representing the analysis result determined to be valid for at least a portion of frequency domain data of the measurement result; a second processing unit that outputs data representing the state information based on at least one first data including data representing the analysis result; a second storage unit storing at least one second data including data representing the state information; as well as The third processing unit diagnoses the state of the electrolysis device based on a plurality of data including the at least one prior information data from the first storage unit and the at least one second data from the second storage unit, and outputs data indicating a diagnosis result of the state.

2. The status diagnosis system according to claim 1, wherein: The first processing unit: By means of the analysis, the analytical validity and analytical validity range of the complex impedance measurement result are determined, and the valid region and invalid region of the complex impedance measurement result are distinguished. Data representing the analysis result in the valid area is output.

3. The status diagnosis system according to claim 1, wherein: The device further includes 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.

4. The status diagnosis system according to claim 3, wherein: The first processing unit: By means of the analysis, the analytical validity and analytical validity range of the complex impedance measurement result are determined, and the valid area and invalid area of ​​the measurement result are distinguished. Data representing the analysis result in the valid area is output.

5. An electrolysis system comprising: the electrolysis device; and The status diagnosis system according to claim 3, The state diagnosis system further includes a fifth processing unit that outputs a control signal for controlling the operating state of the electrolysis device based on the data indicating the prediction result from the fourth processing unit.

6. The electrolysis system according to claim 5, wherein: Also features: a sensor for detecting a composition of at least one fluid supplied to the electrolytic cell and a composition of at least one fluid discharged from the electrolytic cell, and outputting data representing a detection result of the composition; a third storage unit storing data representing at least one external information selected from the group consisting of data representing a supply and demand status of renewable energy, data representing the supply availability of the at least one fluid, data representing a status of a subsequent process of the electrolysis device, and data representing market information on carbon credits; as well as The sixth processing unit formulates an operation plan for the electrolysis device based on a plurality of data including data indicating the analysis result, data indicating the diagnosis result of the state, data indicating the prediction result, the detection result of the composition, and data indicating the at least one external information.

7. The electrolysis system according to claim 6, wherein: The electrolysis device has a plurality of electrolysis cells. The sixth processing unit formulates an operation plan for the electrolysis device based on the plurality of data, and outputs a control signal for controlling the supply amount of the cathode fluid distributed to the plurality of electrolysis cells according to the operation plan.

8. The electrolysis system according to claim 5, wherein: Also features: a sensor for detecting a composition of at least one fluid supplied to the electrolytic cell and a composition of at least one fluid discharged from the electrolytic cell, and outputting data representing a detection result of the composition; a third storage unit storing data representing at least one external information selected from the group consisting of data representing a supply and demand status of renewable energy, data representing the supply availability of the at least one fluid, data representing a status of a subsequent process of the electrolysis device, and data representing market information on carbon credits; as well as The sixth processing unit formulates a maintenance plan for the electrolysis device based on a plurality of data including data indicating the analysis result, data indicating the diagnosis result of the state, data indicating the prediction result, the detection result of the composition, and data indicating the at least one external information.

9. The electrolysis system according to claim 8, wherein: The third storage unit holds data indicating a maintenance plan for electrolysis equipment nationwide or worldwide. The sixth processing unit plans a route that can supply replacement parts required for the electrolysis device in the shortest time and the shortest distance according to the maintenance plan.

10. The electrolysis system according to any one of claims 5 to 9, wherein: The complex impedance measurement result includes at least one signal selected from the group consisting of a direct current, a sine wave, a rectangular wave, a triangle wave, a pulse, and noise. The measurement frequency of the complex impedance is in the range of 0 kHz to 1 GHz.

11. The electrolysis system according to any one of claims 5 to 10, wherein: The first processing unit performs fitting processing using an equivalent circuit model on data representing the measurement result of the complex impedance, and determines that the measurement result in a region where the calculated residual value is within ±5% is a valid region.

12. The electrolysis system according to claim 11, wherein The first processing unit determines the measurement result in a region where the residual value is within ±3% as the valid region.

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

14. The electrolysis system according to any one of claims 5 to 9, wherein: The at least one prior information data also includes at least one selected from a group consisting of data representing operating information of the electrolysis device obtained before the operation of the electrolysis device starts, data representing operating information of a second electrolysis device different from the electrolysis device, and data representing an operation simulation result of the electrolysis device.

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

16. The electrolysis system according to claim 14, wherein: 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 valid range of the analysis, the analysis result, and information on temporal changes therebetween.

17. The electrolysis system according to any one of claims 5 to 9, wherein: The diagnosis result of the state indicates the main cause of the current deterioration of the electrolysis device. The main cause of the degradation includes at least one selected from the group consisting of degradation of the diaphragm, degradation of the cathode catalyst provided at the cathode, degradation of the anode catalyst provided at the anode, overflow due to the operation of the electrolysis device, salt precipitation due to the operation of the electrolysis device, poor fastening of the electrolysis cell, and electrical short circuit of the electrolysis cell.

18. The electrolysis system according to any one of claims 5 to 9, wherein: The diagnosis result of the state indicates the main cause of future deterioration of the electrolysis device. The main cause of the degradation includes at least one selected from the group consisting of degradation of the diaphragm, degradation of the cathode catalyst provided at the cathode, degradation of the anode catalyst provided at the anode, overflow due to the operation of the electrolysis device, salt precipitation due to the operation of the electrolysis device, poor fastening of the electrolysis cell, and electrical short circuit of the electrolysis cell.

19. The electrolysis system according to any one of claims 5 to 9, wherein: The electrolysis device further includes a reference electrode connected to the impedance measuring device.

20. The electrolysis system according to any one of claims 5 to 9, wherein: The fourth processing unit predicts a future state of the electrolysis device by analyzing the at least one third data using a time series machine learning model, and outputs data indicating the prediction result.

21. The electrolysis system according to any one of claims 5 to 9, wherein: The electrolysis device reduces carbon dioxide to produce carbon compounds or reduces nitrogen to produce ammonia.

22. A method for diagnosing the status of an electrolysis device, wherein: The electrolysis device comprises an electrolysis cell, The electrolytic cell has an anode, a cathode, and a separator separating the anode and the cathode. In the state diagnosis method, measuring the complex impedance of the electrolytic cell using an impedance measuring device, and outputting data representing the measurement result of the complex impedance from the impedance measuring device; analyzing data representing the measurement result of the complex impedance by a first processing unit, determining the validity of the analysis result, and outputting data representing the analysis result determined to be valid for at least a portion of the frequency domain data of the measurement result; outputting data indicating status information of the electrolysis device based on at least one first data including data indicating the analysis result by a second processing unit, Using the third processing unit, at least one piece of prior information obtained before the operation of the electrolysis device starts, including data indicating the correspondence between the status information and the diagnosis result of the status of the electrolysis device, is read from the first storage unit, and at least one second piece of data including data indicating the status information is read from the second storage unit. Based on multiple data including the at least one piece of prior information from the first storage unit and the at least one second piece of data from the second storage unit, the status of the electrolysis device is diagnosed, and data indicating the diagnosis result of the status is output.

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