JP-7855575-B2 - Degradation determination support device, water electrolysis device, and degradation determination support method

JP7855575B2JP 7855575 B2JP7855575 B2JP 7855575B2JP-7855575-B2

Inventors

大雲一郎
高見洋史
原田耕佑

Assignees

ＥＮＥＯＳホールディングス株式会社

Dates

Publication Date: 20260508
Application Date: 20211222
Priority Date: 20210413

Claims (5)

A first calculation unit acquires a dataset including multiple reaction condition values and measured voltages related to the water electrolysis reaction of a water electrolysis module, measured or derived from measured values during a first period and a second period following the first period, and calculates a set of parameters for the calculation formula for each period using the dataset and a predetermined calculation formula. A second calculation unit calculates comparison values for each period by substituting predetermined reaction condition values into the calculation formula incorporating the aforementioned parameter group, The system includes a third calculation unit that calculates the degree of deterioration of the water electrolysis module based on the difference between a first comparison value calculated from a calculation formula incorporating the parameter group in the first period and a second comparison value calculated from a calculation formula incorporating the parameter group in the second period. The water electrolysis module comprises an electrode for generating oxygen, an electrode for generating hydrogen, and a diaphragm separating the oxygen-generating electrode and the hydrogen-generating electrode. The above calculation formula calculates the voltage by adding the equilibrium potential of the water electrolysis reaction, the activation overpotential of the oxygen evolution reaction, and the resistance overpotential of the diaphragm. The first calculation unit calculates a calculated voltage by substituting the reaction condition value into the calculation formula, corrects at least one coefficient included in the calculation formula so that the calculated voltage approaches the measured voltage, and calculates the parameter group that includes the corrected coefficient as a component. The second calculation unit calculates the first comparison target value, the calculated voltage (V sim 1), by substituting predetermined reaction condition values into the calculation formula incorporating the parameter group for the first period, and calculates the second comparison target value , the calculated voltage (V sim 2), by substituting the predetermined reaction condition values into the calculation formula incorporating the parameter group for the second period, and the third calculation unit calculates the first degree of degradation (d1) using equation (12): d1 = (V sim 2 - V sim 1) / V sim 1. The second calculation unit calculates the activation overvoltage (η act 1) as the first comparison value by substituting predetermined reaction condition values into the activation overvoltage (η act ) term in the calculation formula incorporating the parameter group for the first period, and calculates the activation overvoltage (η act 2) as the second comparison value by substituting the predetermined reaction condition values into the activation overvoltage (η act ) term in the calculation formula incorporating the parameter group for the second period , and the third calculation unit calculates the second degree of degradation ( d2 ) using equation (13): d2 = (η act 2 - η act 1) / η act 1, and the second calculation unit calculates the resistance overvoltage (η IR ) as the first comparison value by substituting predetermined reaction condition values into the resistance overvoltage (η IR) term in the calculation formula incorporating the parameter group for the first period 1) calculate the resistance overvoltage (η IR 2) as the second comparison value by substituting the predetermined reaction condition value into the term for the resistance overvoltage (η IR ) in the calculation formula incorporating the parameter group in the second period, and the third calculation unit performs at least one of the following: (14) calculate the third degree of degradation (d3) using equation: d3 = (η IR 2 - η IR 1) / η IR 1. Deterioration determination support device.
The calculation of the first degree of deterioration (d1), the calculation of the second degree of deterioration (d2), and the calculation of the third degree of deterioration (d3) are performed , The deterioration determination support device according to claim 1.
The first period is the period during which the water electrolysis module is presumed to be in an undegraded state. A deterioration determination support device according to claim 1 or 2.
Water electrolysis module, A deterioration determination support device according to any one of claims 1 to 3, comprising Water electrolysis equipment.
A dataset is obtained that includes multiple reaction condition values and measured voltages related to the water electrolysis reaction of the water electrolysis module, measured or derived from measured values during the first period and the second period following the first period . Using the aforementioned dataset and a predetermined calculation formula, the parameter set of the calculation formula for each period is calculated. By substituting predetermined reaction condition values into the calculation formula incorporating the aforementioned parameter group, the comparison values for each period are calculated. This includes calculating the degree of deterioration of the water electrolysis module based on the difference between a first comparison value calculated from a calculation formula incorporating the parameter group in the first period and a second comparison value calculated from a calculation formula incorporating the parameter group in the second period. The water electrolysis module comprises an electrode for generating oxygen, an electrode for generating hydrogen, and a diaphragm separating the oxygen-generating electrode and the hydrogen-generating electrode. The above calculation formula calculates the voltage by adding the equilibrium potential of the water electrolysis reaction, the activation overpotential of the oxygen evolution reaction, and the resistance overpotential of the diaphragm. The calculation of the parameter group includes substituting the reaction condition values into the calculation formula to calculate the calculated voltage, correcting at least one coefficient included in the calculation formula so that the calculated voltage approaches the measured voltage, and calculating the parameter group that includes the corrected coefficient as a component. In calculating the comparison value, the calculated voltage (V sim 1) as the first comparison value is calculated by substituting predetermined reaction condition values into the calculation formula incorporating the parameter group for the first period, the calculated voltage (V sim 2) as the second comparison value is calculated by substituting the predetermined reaction condition values into the calculation formula incorporating the parameter group for the second period, and in calculating the degree of degradation, the first degree of degradation (d1) is calculated using equation (12): d1 = (V sim 2 - V sim 1) / V sim 1. In calculating the comparison value, the first comparison value of activation overvoltage (η act 1) is calculated by substituting a predetermined reaction condition value into the term of activation overvoltage (η act ) in the calculation formula incorporating the parameter group for the first period, and the second comparison value of activation overvoltage (η act 2) is calculated by substituting the predetermined reaction condition value into the term of activation overvoltage (η act ) in the calculation formula incorporating the parameter group for the second period , and in calculating the degree of degradation, the second degree of degradation ( d2 ) is calculated using equation (13): d2 = (η act 2 - η act 1) / η act 1, and in calculating the comparison value, the first comparison value of resistance overvoltage (η IR ) is calculated by substituting a predetermined reaction condition value into the term of resistance overvoltage (η IR) in the calculation formula incorporating the parameter group for the first period At least one of the following is performed: 1) calculate the resistance overvoltage (η IR ) in the calculation formula incorporating the parameter group in the second period, substitute the predetermined reaction condition value into the term to calculate the resistance overvoltage (η IR 2) as the second comparison target value , and in calculating the degree of degradation, calculate the third degree of degradation (d3) using equation (14): d3 = (η IR 2 - η IR 1) / η IR 1. Deterioration determination support method.

Description

The present invention relates to a deterioration determination support device, a water electrolysis device, and a deterioration determination support method. In recent years, renewable energy sources such as wind and solar power have attracted attention as energy sources that can reduce carbon dioxide emissions during the generation process compared to energy obtained from thermal power generation. Electricity generated from renewable energy can be stored in stationary energy storage systems to smooth out output power. Recently, water electrolysis modules, which produce hydrogen gas by electrolyzing water, have become increasingly popular as stationary energy storage systems. Examples of water electrolysis modules include solid polymer type water electrolysis modules, alkaline type water electrolysis modules, and solid oxide type water electrolysis modules, as disclosed in Patent Document 1. Japanese Patent Publication No. 2018-165392 This is a schematic diagram of a water electrolysis apparatus according to an embodiment.This figure shows the current-voltage characteristics of a water electrolysis module.This is a flowchart illustrating a method for supporting deterioration assessment, as an example.Figure 4(A) shows the relationship between time and current in the water electrolysis operation test performed in the example. Figure 4(B) shows the corrected parameter group, various voltages, and degree of degradation in the example. The present invention will be described below with reference to the drawings, based on preferred embodiments. The embodiments are illustrative and not limit the technical scope of the present invention; not all features or combinations thereof described in the embodiments are necessarily essential to the invention. Therefore, many design modifications, such as changes, additions, and deletions of components, are possible within the scope that does not depart from the spirit of the invention as defined in the claims. A new embodiment with design modifications will possess the combined effects of both the embodiment and the modification. In the embodiments, such design modifications are emphasized with notations such as "of this embodiment" or "in this embodiment," but design modifications are also permitted even without such notations. Any combination of the above components is also valid as an embodiment of the present invention. The same or equivalent components, members, and processes shown in each drawing are denoted by the same reference numerals, and redundant explanations are omitted as appropriate. Furthermore, the scale and shape of each part shown in each figure are set for convenience to facilitate explanation and are not to be interpreted restrictively unless specifically mentioned. Furthermore, where terms such as "first," "second," etc., are used in this specification or claims, these terms do not indicate any order or importance, but are used to distinguish one configuration from another. In addition, some components that are not important for describing the embodiments are omitted from the drawings. Figure 1 is a schematic diagram of a water electrolysis apparatus according to an embodiment. The water electrolysis apparatus 1 comprises a water electrolysis module 2, a power supply 4, a first supply mechanism 6, a second supply mechanism 8, and a control device 10. In this disclosure, the water electrolysis module 2 may consist of a single cell, multiple cells, a stack of multiple cells connected together, multiple stacks, or a combination thereof. The water electrolysis module 2 is an electrolytic cell that generates hydrogen by the electrolysis of water. In this embodiment, the water electrolysis module 2 is a solid polymer membrane type water electrolysis device that utilizes a solid ion exchange membrane. The water electrolysis module 2 includes an oxygen generation electrode 12, an oxygen generation electrode chamber 14, a hydrogen generation electrode 16, a hydrogen generation electrode chamber 18, and a diaphragm 20. The oxygen generation electrode 12 is defined as the anode, as it is the electrode where the oxidation reaction occurs. The oxygen generation electrode 12 has a catalyst layer 12a and a gas diffusion layer 12b. The catalyst layer 12a contains, for example, iridium (Ir) or platinum (Pt) as a catalyst. The catalyst layer 12a may also contain other metals or metal compounds. The catalyst layer 12a is positioned so as to be in contact with one main surface of the diaphragm 20. The gas diffusion layer 12b is composed of a conductive porous material or the like. Known materials can be used to constitute the gas diffusion layer 12b. The oxygen generation electrode 12 is housed in the oxygen generation electrode chamber 14. The space in the oxygen generation electrode chamber 14 excluding the oxygen generation electrode 12 constitutes a water and oxygen flow path. The hydrogen generation electrode 16 is defined as the cathode, which is the electrode wher