Electrochemical system

Abstract

An electrochemical system is provided that includes a water electrolysis stack having an anode and a cathode. The system includes: a reaction fluid supply line supplying a reaction fluid to an anode; a first gas-liquid separator in the reaction fluid supply line to separate the reaction fluid into a gaseous component and a liquid component; and a first filter portion located upstream of the first gas-liquid separator to filter the reaction fluid. The system also includes a first circulation line that circulates the liquid reaction fluid from the anode back to the first gas-liquid separator. Further, a second gas-liquid separator in an exhaust fluid discharge line is connected to the cathode, and a second circulation line is configured to maintain an ionic purity of the exhaust fluid. The system also includes a mechanism that monitors ionic conductivity and selectively controls operation of the water electrolysis stack based on the detected ionic level.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of Korean Patent Application No. 10-2024-0063476, filed with the Korean Intellectual Property Office on May 14, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to electrochemical systems, and more specifically, to water electrolysis systems designed to enhance the performance, durability, and stability of water electrolysis reactors by incorporating mechanisms for monitoring and controlling the ionic purity of the reaction and discharged fluids. The system includes advanced filtration and sensor technologies that allow for real-time adjustment and maintenance, ensuring optimal operation and extended lifespan of the water electrolysis reactor. Background Technology

[0004] The need for research and development of alternative energy sources continues to increase in response to global warming and the depletion of fossil fuels. Hydrogen energy is gaining attention as a practical solution to environmental and energy problems.

[0005] In particular, hydrogen is of great interest as a future energy carrier because of its high energy density and suitability for grid-scale applications.

[0006] A water electrolysis reactor (which is one type of electrochemical device) is a device that produces hydrogen and oxygen by electrochemically splitting water. A water electrolysis reactor can be configured by stacking dozens or hundreds of water electrolysis cells (water electrolysis batteries) (unit cells (unit cells)) in series.

[0007] Meanwhile, when the reaction fluid (reactant) (e.g., water) supplied to an electrochemical device (e.g., a water electrolyzer) contains ions and foreign matter (impurities), the performance, durability, and reliability of the electrochemical device deteriorate. Therefore, it is necessary to remove ions and foreign matter contained in the reaction fluid as much as possible. Summary of the Invention

[0008] This disclosure aims to provide a filtration device for an electrochemical device that can ensure the performance of a water electrolyzer and improve its durability and stability.

[0009] Specifically, this disclosure is committed to allowing low-quality reaction fluids (e.g., reaction fluids with high ionic conductivity) to flow along a first bypass line and be reprocessed (e.g., deionized) without being supplied to the water electrolysis reactor.

[0010] In addition, this disclosure aims to extend the life of water electrolyzers and minimize the degradation of the durability and stability of water electrolyzers caused by the supply of low-quality reaction fluids to the water electrolyzers.

[0011] This disclosure also aims to improve the quality and recyclability of reaction fluids and reduce the amount of reaction fluids used.

[0012] Specifically, this disclosure is committed to reusing the effluent discharged from the cathode as a reaction fluid.

[0013] This disclosure also aims to flush (clean) the cathode by using the discharged fluid without the need for a separate flushing device.

[0014] The objectives achieved by the implementation methods are not limited to those described above, but also include objectives or effects that can be understood from the schemes or implementation methods described below.

[0015] To achieve the above objectives, an exemplary embodiment of this disclosure provides an electrochemical system comprising: a water electrolysis reactor including an anode and a cathode; a reaction fluid supply line configured to supply reaction fluid to the anode; a first gas-liquid separator disposed in the reaction fluid supply line and configured to separate the reaction fluid into a gaseous reaction fluid and a liquid reaction fluid; a first filter section disposed in the reaction fluid supply line, located upstream of the first gas-liquid separator, and configured to filter the reaction fluid; a first circulation line configured to connect the first gas-liquid separator and the anode, and to circulate the liquid reaction fluid passing through the anode to the first gas-liquid separator; and a first bypass line, one end of which is disposed between the first gas-liquid separator and the water electrolysis reactor and connected to the reaction fluid supply line, and the other end of which is disposed upstream of the first filter section and connected to the reaction fluid supply line.

[0016] In some embodiments, the electrochemical system includes a water electrolyzer having an anode and a cathode; a reaction fluid supply line configured to supply reaction fluid to the anode; a first gas-liquid separator located in the reaction fluid supply line and configured to separate the reaction fluid into a gaseous reaction fluid and a liquid reaction fluid; a first filter section located upstream of the first gas-liquid separator within the reaction fluid supply line and configured to filter the reaction fluid; and a first circulation line connecting the first gas-liquid separator and the anode to circulate the liquid reaction fluid that has passed through the anode back to the first gas-liquid separator. Furthermore, the system includes a first bypass line, one end of which is located between the first gas-liquid separator and the water electrolyzer, and the other end upstream of the first filter section, with both ends connected to the reaction fluid supply line.

[0017] The system may further include a first ion sensor located upstream of the first gas-liquid separator in the reaction fluid supply line, configured to sense the ionic conductivity of the reaction fluid, wherein the operation of the water electrolysis reactor is selectively controlled based on the detection of the first ion sensor. In some preferred aspects, a first valve, serving as a three-way valve, may be located in the reaction fluid supply line and connected to one end of a first bypass line, wherein a second ion sensor is located in at least one of the reaction fluid supply line and the first circulation line, configured to sense the ionic conductivity of the liquid reaction fluid, wherein the first three-way valve selectively switches the flow of the liquid reaction fluid from the downstream side to the upstream side of the first gas-liquid separator based on the detection of the second ion sensor. In some preferred aspects, after a preset reference time has elapsed following the switching of the liquid reaction fluid flow from the downstream side to the upstream side of the first gas-liquid separator, the first filter section may be replaced when the ionic conductivity of the liquid reaction fluid detected by the second ion sensor is equal to or higher than a preset reference ionic conductivity.

[0018] In some embodiments, the system further includes: a discharge fluid line connected to the cathode and configured to discharge the discharged fluid from the cathode; a second gas-liquid separator located in the discharge fluid line and configured to separate the discharged fluid into gaseous and liquid components; and a second circulation line connecting the second gas-liquid separator to the reaction fluid supply line to circulate the liquid discharged fluid back to the reaction fluid supply line. Furthermore, in some preferred aspects, the system may include a reaction fluid storage section and a pretreatment filter section, the reaction fluid storage section being located upstream of the first filter section in the reaction fluid supply line and configured to store the reaction fluid, the pretreatment filter section being located upstream of the reaction fluid storage section in the reaction fluid supply line and configured to filter the reaction fluid, and the second circulation line being connected to the reaction fluid storage section. In some preferred aspects, the system may further include a second filter section and a second bypass line, the second filter section being located in the second circulation line and configured to filter the liquid discharged fluid, one end of the second bypass line being located downstream of the second filter section and connected to the second circulation line, and the other end of the second bypass line being connected to the cathode.

[0019] Furthermore, in some preferred aspects, a second valve (such as a three-way valve) may be located in the second circulation line and connected to one end of the second bypass line, and a third ion sensor may be located in at least one of the discharged fluid discharge line and the second circulation line, configured to sense the ionic conductivity of the discharged liquid, wherein the second three-way valve selectively switches the flow of the discharged liquid from the downstream side of the second filter section to the cathode based on the detection of the third ion sensor. In some preferred aspects, the second filter section may be replaced when, after a preset reference time has elapsed since the discharged liquid flow switched from the downstream side of the second filter section to the cathode, the ionic conductivity of the discharged liquid is detected by the third ion sensor to be equal to or higher than the preset reference ionic conductivity.

[0020] In some embodiments, the system includes a reactive fluid storage unit located upstream of the first filter unit, configured to store the reactive fluid before it is supplied to the first filter unit. In some preferred aspects, the system may further include a system configured to selectively stop operation of the water electrolysis reactor based on ionic conductivity detected by first and second ion sensors. Additionally, in some preferred aspects, the system may be configured to trigger an alarm or notification when the ionic conductivity detected by the first or second ion sensor exceeds a predetermined threshold.

[0021] According to another exemplary embodiment of this disclosure, the electrochemical system may include: a first ion sensor disposed in a reaction fluid supply line, located upstream of a first gas-liquid separator, and configured to sense the ionic conductivity of the reaction fluid, wherein operation of the water electrolysis reactor is selectively stopped based on the result detected by the first ion sensor.

[0022] According to an exemplary embodiment of this disclosure, the electrochemical system may include a first three-way valve disposed in a reaction fluid supply line and connected to one end of a first bypass line.

[0023] According to an exemplary embodiment of this disclosure, the electrochemical system may include: a second ion sensor disposed in at least one of a reaction fluid supply line and a first circulation line, and the second ion sensor being configured to sense the ionic conductivity of the liquid reaction fluid, wherein a first three-way valve selectively switches the flow of the liquid reaction fluid from the downstream side of the first gas-liquid separator to the upstream side of the first gas-liquid separator based on the result detected by the second ion sensor.

[0024] According to an exemplary embodiment of this disclosure, when a preset reference time has elapsed after the flow of the liquid reaction fluid has switched from the downstream side of the first gas-liquid separator to the upstream side of the first gas-liquid separator, and when the ionic conductivity of the liquid reaction fluid detected by the second ion sensor is equal to or higher than the preset reference ionic conductivity, the first filter section can be replaced.

[0025] According to an exemplary embodiment of the present disclosure, the electrochemical system may include: a discharge fluid discharge line connected to a cathode and configured to discharge discharge fluid from the cathode; a second gas-liquid separator disposed in the discharge fluid discharge line and configured to separate the discharged fluid into a gaseous discharge fluid and a liquid discharge fluid; and a second circulation line configured to connect the second gas-liquid separator and a reaction fluid supply line and to circulate the liquid discharge fluid to the reaction fluid supply line.

[0026] According to an exemplary embodiment of the present disclosure, an electrochemical system may include: a reaction fluid storage section disposed in a reaction fluid supply line, located upstream of a first filter section, and configured to store reaction fluid; and a pretreatment filter section disposed in a reaction fluid supply line, located upstream of the reaction fluid storage section, and configured to filter reaction fluid, wherein a second circulation line is connected to the reaction fluid storage section.

[0027] According to an exemplary embodiment of this disclosure, the electrochemical system may include: a second filter section disposed in a second circulation line and configured to filter liquid discharge fluid.

[0028] According to an exemplary embodiment of the present disclosure, the electrochemical system may include: a second bypass line, one end of which is disposed downstream of the second filter section and connected to a second circulation line, and the other end of which is connected to the cathode.

[0029] According to an exemplary embodiment of this disclosure, the electrochemical system may include: a second three-way valve disposed in a second circulation line and connected to one end of a second bypass line.

[0030] According to an exemplary embodiment of the present disclosure, the electrochemical system may include: a third ion sensor disposed in at least one of a discharge fluid line and a second circulation line, and configured to sense the ionic conductivity of the liquid discharge fluid, wherein a second three-way valve selectively switches the flow of the liquid discharge fluid from the downstream side of the second filter section to the cathode based on the result detected by the third ion sensor.

[0031] According to an exemplary embodiment of this disclosure, when a preset reference time has elapsed after the flow of the liquid discharge fluid has switched from the downstream side of the second filter section to the cathode, and when the ionic conductivity of the liquid discharge fluid detected by the third ion sensor is equal to or higher than the preset reference ionic conductivity, the second filter section can be replaced.

[0032] According to an exemplary embodiment of the present disclosure, the electrochemical system may include: a discharge fluid storage section disposed in a second circulation line, disposed downstream of a second filter section, and storing the discharged fluid in liquid reaction fluid form. Attached Figure Description

[0033] Figure 1 This is a view used to illustrate an electrochemical system according to an embodiment of the present disclosure.

[0034] Figure 2 This is a view used to illustrate the movement paths of the reaction fluid and the discharge fluid in an electrochemical system according to embodiments of the present disclosure.

[0035] Figure 3 This is a view used to illustrate the movement path of the reaction fluid along a first bypass line in an electrochemical system according to an embodiment of the present disclosure.

[0036] Figure 4 It is a view used to explain the movement path of fluid discharged in an electrochemical system according to an embodiment of the present disclosure along a second bypass line. Detailed Implementation

[0037] In the following, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0038] However, the spirit of this disclosure is not limited to the embodiments described herein, but can be implemented in various different forms. Within the scope of the spirit of this disclosure, one or more components in the embodiments can be selectively combined and substituted.

[0039] Furthermore, unless otherwise expressly and explicitly defined and stated, the terms used in the embodiments of this disclosure (including technical and scientific terms) are to be interpreted as having the meaning commonly understood by one of ordinary skill in the art to which this disclosure pertains. The meanings of commonly used terms, such as those defined in dictionaries, can be interpreted in light of the contextual meaning of related technologies.

[0040] Furthermore, the terminology used in the embodiments of this disclosure is for the purpose of explaining the embodiments and is not intended to limit the disclosure.

[0041] In this specification, unless otherwise specified, the singular form may also include the plural form. The expression "at least one (or one or more) of A, B, and C" may include one or more of all combinations that can be made by combining A, B, and C.

[0042] Furthermore, terms such as first, second, A, B, (a) and (b) may be used to describe the constituent elements of embodiments of this disclosure.

[0043] These terms are used only for the purpose of distinguishing one component from another, and the nature, sequence, or order of the components are not limited by these terms.

[0044] Furthermore, when a component is described as being “connected,” “coupled,” or “attached” to another component, a component may be directly connected, coupled, or directly connected to another component, or connected, coupled, or attached to another component through another component in between.

[0045] Furthermore, the statement "one component is positioned above or below another component" includes not only cases where the two components are in direct contact with each other, but also cases where one or more other components are positioned between the two components. The statement "above or below" can refer to both the downward and upward directions of a component.

[0046] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. As used herein, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” are intended to also include the plural forms. These terms are intended only to distinguish one component from another, and these terms do not limit the nature, order, or sequence of the constituent components. It should also be understood that when the terms “comprises” and / or “comprising” are used in this specification, they specify the presence of a feature, integral, step, operation, element, and / or component, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or combinations thereof. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items. Throughout the specification, unless explicitly stated otherwise, the word “comprise” and variations such as “comprises” or “comprising” will be understood to imply the inclusion of elements, but do not exclude any other elements. Furthermore, the terms “unit,” “-er,” “-or,” and “module” described in the specification refer to a unit for performing at least one function and operation, and can be implemented by hardware components or software components and combinations thereof.

[0047] Although the exemplary implementation is described as using multiple units to perform the exemplary process, it should be understood that the exemplary process can also be performed by one or more modules. Furthermore, it should be understood that the term controller / control unit refers to a hardware device that includes a memory and a processor and is specifically programmed to perform the processes described herein. The memory is configured to store modules, and the processor is specifically configured to execute said modules to perform one or more processes further described below.

[0048] Furthermore, the control logic of this disclosure may be embodied in a non-volatile computer-readable medium containing executable program instructions that can be executed by a processor, controller, or the like. Examples of computer-readable media include, but are not limited to, ROM, RAM, optical disc (CD-ROM), magnetic tape, floppy disk, flash memory drive, smart card, and optical data storage devices. The computer-readable medium may also be distributed across a network-connected computer system, enabling it to be stored and executed in a distributed manner, for example, via a telematics server or a controller area network (CAN).

[0049] Unless otherwise specified or obvious from the context, as used herein, the term “about” should be understood as being within the normal tolerance range in the field, such as within 2 standard deviations of the mean. “About” can be understood as being within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated value. Unless the context otherwise clarifies, all numerical values ​​provided herein are modified by the term “about”.

[0050] refer to Figures 1 to 4 An electrochemical system 10 according to an embodiment of the present disclosure includes a water electrolysis reactor 20, which includes an anode 22 and a cathode 24; a reaction fluid supply line 130 through which reaction fluid is supplied to the anode 22; a first gas-liquid separator 140 disposed in the reaction fluid supply line 130 and configured to separate the reaction fluid into gaseous reaction fluid and liquid reaction fluid; and a first filter section 132 disposed in the reaction fluid supply line 130, located at the first gas-liquid separator 140. Upstream of 0, and configured to filter the reaction fluid; a first circulation line 150, configured to connect the first gas-liquid separator 140 and the anode 22 and configured to circulate the liquid reaction fluid that has passed through the anode 22 to the first gas-liquid separator 140; and a first bypass line 160, one end of which is disposed between the first gas-liquid separator 140 and the water electrolysis reactor 20 and connected to the reaction fluid supply line 130, and the other end of which is disposed upstream of the first filter section 132 and connected to the reaction fluid supply line 130.

[0051] For reference, the electrochemical system 10 according to embodiments of this disclosure can be used to generate electrochemical reactions between various reaction fluids, depending on the desired conditions and design specifications. This disclosure is not limited or restricted by the type and properties of the reaction fluids used in the electrochemical system 10.

[0052] For example, the electrochemical system 10 according to embodiments of the present disclosure can be used to generate hydrogen and oxygen by electrochemically decomposing water (reaction fluid).

[0053] The water electrolysis reactor 20 includes an anode 22 and a cathode 24 and is located in a first circulation line 150 to produce hydrogen and oxygen by electrochemically decomposing water (the reaction fluid).

[0054] The water electrolysis reactor 20 can have various structures capable of producing hydrogen and oxygen by electrochemically decomposing the reaction fluid. This disclosure is not limited or restricted by the type and structure of the water electrolysis reactor 20.

[0055] For example, a water electrolyzer 20 can be manufactured by stacking multiple cell pools (not shown) in a preset reference stacking direction.

[0056] More specifically, a unit cell may include a reaction layer (not shown) and diaphragms (not shown) stacked on two opposite surfaces of the reaction layer, respectively. The water electrolysis stack 20 can be configured by stacking multiple unit cells in a reference stacking direction and then fastening end plates (not shown) to two opposite ends of the stack of multiple unit cells.

[0057] The reaction layer can have various structures capable of generating electrochemical reactions with a reaction fluid (e.g., water). This disclosure is not limited or restricted by the type and structure of the reaction layer.

[0058] For example, the reaction layer may include a membrane electrode assembly (MEA) (not shown), a first porous transport layer (not shown) in close contact with one surface of the membrane electrode assembly, and a second porous transport layer (not shown) in close contact with the other surface of the membrane electrode assembly.

[0059] Membrane electrode assemblies can be modified in structure and materials to suit various requirements and design specifications. This disclosure is not limited or restricted by the structure and materials of the membrane electrode assembly.

[0060] For example, a membrane electrode assembly can be configured by attaching a catalyst electrode layer (e.g., an anode electrode layer and a cathode electrode layer) that generates an electrochemical reaction to two opposing surfaces of an electrolyte membrane.

[0061] The first and second porous transport layers can uniformly distribute the reactive fluid and each has a porous structure with pores of a predetermined size.

[0062] For reference, water supplied to the anode 22 (anode electrode layer), which serves as the oxidation electrode for water electrolysis, is separated into hydrogen ions (protons), electrons, and oxygen. Hydrogen ions move through the electrolyte membrane to the cathode 24 (cathode electrode layer), which serves as the reduction electrode, and electrons move to the cathode 24 via an external circuit. Furthermore, oxygen can be discharged through the outlet of the anode 22, and hydrogen ions and electrons can be converted into hydrogen in the cathode 24.

[0063] The reaction fluid supply line 130 is configured to supply reaction fluid (e.g., water) to the water electrolyzer 20.

[0064] The reaction fluid supply line 130 may have various structures capable of supplying reaction fluid. This disclosure is not limited or restricted by the structure and shape of the reaction fluid supply line 130.

[0065] For example, the reaction fluid supply line 130 may be defined as a substantially straight shape. According to another embodiment of this disclosure, the reaction fluid supply line may be defined as a curved shape or other shapes.

[0066] Furthermore, the reaction fluid supply line 130 may be equipped with various types of auxiliary devices, such as a pump (not shown) configured to forcibly move the reaction fluid along the reaction fluid supply line 130, and a valve (not shown) configured to selectively open or close the reaction fluid supply line 130. This disclosure is not limited or restricted by the type or number of auxiliary devices.

[0067] According to an exemplary embodiment of this disclosure, the electrochemical system 10 may include: a reaction fluid storage unit 120 disposed in a reaction fluid supply line 130, upstream of a first filter unit 132, and configured to store the reaction fluid; and a pretreatment filter unit 110 disposed in the reaction fluid supply line 130, upstream of the reaction fluid storage unit 120, and configured to filter the reaction fluid. A second circulation line 230 may be connected to the reaction fluid storage unit 120.

[0068] The reaction fluid storage unit 120 may have various structures capable of storing reaction fluid. This disclosure is not limited or restricted by the structure and shape of the reaction fluid storage unit 120.

[0069] For example, the reaction fluid storage unit 120 can be configured as a hollow box. The reaction fluid that has passed through the pretreatment filter unit 110 can be temporarily stored in the reaction fluid storage unit 120 before being supplied to the first gas-liquid separator 140 to be separated into gaseous reaction fluid and liquid reaction fluid.

[0070] Furthermore, an outlet (not shown) may be provided at approximately the lower end of the reaction fluid storage section 120 and configured to selectively discharge the reaction fluid in the reaction fluid storage section 120 to the outside.

[0071] The pretreatment filter section 110 may have various structures capable of filtering out ions and foreign matter (impurities) contained in the reaction fluid. This disclosure is not limited or restricted by the type and structure of the pretreatment filter section 110.

[0072] The first gas-liquid separator 140 is connected to the reaction fluid supply line 130 and is configured to separate the reaction fluid into a gaseous reaction fluid (e.g., oxygen) and a liquid reaction fluid (e.g., water).

[0073] Various separation devices capable of separating a reaction fluid into a gaseous reaction fluid and a liquid reaction fluid can be used as the first gas-liquid separator 140. This disclosure is not limited or restricted by the type and structure of the first gas-liquid separator 140.

[0074] For example, the first gas-liquid separator 140 may be configured as a hollow box. For example, a reaction fluid supply line 130 may be connected to approximately the central portion of the first gas-liquid separator 140. A first discharge line 142 may be located approximately at the lower end of the first gas-liquid separator 140 and configured to selectively discharge the liquid reaction fluid in the first gas-liquid separator 140 to the outside. Furthermore, a level sensor (not shown) may be located in the first gas-liquid separator 140 and configured to detect the level of the liquid reaction fluid.

[0075] The first filter section 132 is disposed in the reaction fluid supply line 130, located upstream of the first gas-liquid separator 140, and is configured to filter the reaction fluid to be supplied to the first gas-liquid separator 140.

[0076] Various ion filters capable of filtering ions and foreign matter (impurities) contained in the reaction fluid can be used as the first filter section 132. This disclosure is not limited or restricted by the type and characteristics of such ion filters. For example, pre-filters, carbon filters, RO membrane filters, ion exchange resins, UV lamps, etc., can be used as the first filter section 132.

[0077] For reference, embodiments of the present disclosure are described in which the first filter section 132 includes a single ion filter. However, according to another embodiment of the present disclosure, the first filter section can be configured by connecting multiple ion filters in parallel or in series.

[0078] The first circulation line 150 can be configured to connect the first gas-liquid separator 140 and the anode 22. The liquid reaction fluid that has passed through the anode 22 can circulate along the first circulation line 150 back to the first gas-liquid separator 140.

[0079] More specifically, the liquid reaction fluid separated by the first gas-liquid separator 140 can be supplied to the anode 22 of the water electrolysis reactor 20. The liquid reaction fluid that has passed through the anode 22 can be supplied back to the first gas-liquid separator 140 along the first circulation line 150.

[0080] The first circulation line 150 may have various configurations that allow connection between the outlet of the anode 22 and the first gas-liquid separator 140. This disclosure is not limited or restricted by the configuration or shape of the first circulation line 150.

[0081] In the following text, the connection of the first circulation line 150 to the side of the first gas-liquid separator 140 will be described (based on...). Figure 1 According to another embodiment of this disclosure, the circulation line may be connected to the upper part or other part of the first gas-liquid separator.

[0082] Specifically, the outlet end of the first circulation line 150 can be connected to the first gas-liquid separator 140, such that the outlet end of the first circulation line 150 is positioned at a position higher than the liquid level of the liquid reaction fluid separated by the first gas-liquid separator 140 (e.g., the uppermost side of the first gas-liquid separator).

[0083] The first bypass line 160 is configured to allow the liquid reactive fluid separated by the first gas-liquid separator 140 to selectively flow to the upstream side of the first gas-liquid separator 140 (the upstream side of the first filter section) and not to be supplied to the water electrolysis reactor 20.

[0084] More specifically, one end of the first bypass line 160 is disposed between the first gas-liquid separator 140 and the water electrolysis stack 20 (e.g., the anode inlet) and connected to the reaction fluid supply line 130, and the other end of the first bypass line 160 is disposed upstream of the first filter section 132 (e.g., between the reaction fluid storage section and the first filter section) and connected to the reaction fluid supply line 130.

[0085] The first bypass line 160 can have different structures depending on the required conditions and design specifications. This disclosure is not limited or restricted by the structure and shape of the first bypass line 160. For example, the first bypass line 160 can have an approximately straight shape. According to another embodiment of this disclosure, the first bypass line can have a curved shape or other shapes.

[0086] According to an exemplary embodiment of this disclosure, the electrochemical system 10 may include first ion sensors 171 and 172 disposed in the reaction fluid supply line 130, upstream of the first gas-liquid separator 140, and configured to sense the ionic conductivity of the reaction fluid. Operation of the water electrolysis reactor 20 may be selectively stopped based on the results detected by the first ion sensors 171 and 172.

[0087] Various ion sensors capable of sensing the ionic conductivity of a reactive fluid can be used as first ion sensors 171 and 172. This disclosure is not limited or restricted by the type and structure of the first ion sensors 171 and 172.

[0088] In the following description, an embodiment in which the first ion sensors 171 and 172 are respectively disposed in the reaction fluid storage section 120 and the reaction fluid supply line 130 (e.g., between the pretreatment filter section and the reaction fluid storage section) will be described.

[0089] For example, refer to Figure 2When the ionic conductivity of the reaction fluid sensed by the first ion sensors 171 and 172 is lower than a preset reference ionic conductivity (e.g., 0.1 μS / cm), the reaction fluid stored in the reaction fluid storage unit 120 can be supplied to the water electrolysis reactor 20 via the first gas-liquid separator 140, and the water electrolysis reactor 20 can operate normally.

[0090] Conversely, if the ionic conductivity of the reaction fluid sensed by the first ion sensors 171 and 172 is higher than a preset reference ionic conductivity (e.g., 0.1 μS / cm), it can be determined that the lifespan of the pretreatment filter section has ended, and the operation of the water electrolysis reactor 20 can be stopped.

[0091] Specifically, when the time for replacing the pretreatment filter section 110 is reached (in the case where the ionic conductivity of the reaction fluid sensed by the first ion sensors 171 and 172 is higher than the reference ionic conductivity), the alarm generation unit (not shown) generates a visual alarm signal (e.g., a notification window on the control program screen) or an audible alarm signal to allow the operator to recognize the end of the life of the pretreatment filter section 110 and thus allow the operator to replace the pretreatment filter section 110 at the end of its life in a timely manner.

[0092] As described above, in the embodiments of this disclosure, first ion sensors 171 and 172 are disposed in the reaction fluid supply line 130, and the operation of the water electrolyzer 20 is selectively stopped based on the results detected by the first ion sensors 171 and 172. Therefore, the beneficial effects of minimizing the supply of low-quality reaction fluid to the water electrolyzer 20 and improving durability and stability can be achieved.

[0093] According to an exemplary embodiment of the present disclosure, the electrochemical system 10 may include a first three-way valve 162 disposed in the reaction fluid supply line 130 and connected to one end of the first bypass line 160.

[0094] Various three-way valves capable of allowing the liquid reactive fluid supplied from the first gas-liquid separator 140 to the water electrolysis reactor 20 to selectively flow to the first bypass line 160 can be used as the first three-way valve 162. This disclosure is not limited or restricted by the type and structure of the first three-way valve 162.

[0095] For example, the first three-way valve 162 may include a first port (not shown), a second port (not shown), and a third port (not shown). Liquid reactive fluid discharged from the first gas-liquid separator 140 is introduced into the first port. The second port is configured to guide the liquid reactive fluid that has passed through the first port to the water electrolysis reactor 20. The third port is connected to the first bypass line 160 and configured to guide the reactive fluid that has passed through the first port to the first bypass line 160. The first three-way valve 162 can selectively switch the movement path of the liquid reactive fluid by opening or closing the first to third ports.

[0096] In this context, the operation of opening or closing the first to third ports is defined as including both the operation of fully opening or closing the first to third ports and the operation of adjusting the opening degree (valve opening degree) (e.g., adjusting the opening degree of the port).

[0097] According to an exemplary embodiment of this disclosure, the electrochemical system 10 may include second ion sensors 173, 174, and 175, which are disposed in at least one of the reaction fluid supply line 130 and the first circulation line 150 and configured to sense the ionic conductivity of the liquid reaction fluid. A first three-way valve 162 may selectively switch the flow of the liquid reaction fluid from the downstream side of the first gas-liquid separator 140 to the upstream side of the first gas-liquid separator 140 based on the results detected by the second ion sensors 173, 174, and 175.

[0098] In the following, embodiments in which the second ion sensors 173, 174 and 175 are respectively disposed in the first gas-liquid separator 140, the reaction fluid supply line 130 (e.g., between the first gas-liquid separator and the water electrolysis reactor) and the first circulation line 150 will be described.

[0099] Various ion sensors capable of sensing the ionic conductivity of liquid reactive fluids can be used as second ion sensors 173, 174, and 175. This disclosure is not limited or restricted by the type and structure of the second ion sensors 173, 174, and 175.

[0100] Specifically, the movement path of the liquid reaction fluid can be controlled by controlling the first three-way valve 162 based on the results detected by the second ion sensors 173, 174 and 175.

[0101] That is, the first three-way valve 162 can be configured to allow the liquid reaction fluid to selectively flow from the downstream side of the first gas-liquid separator 140 to the upstream side of the first gas-liquid separator 140 (the upstream side of the first filter section) based on the results detected by the second ion sensors 173, 174 and 175.

[0102] For example, refer to Figure 3If the ionic conductivity of the liquid reactive fluid sensed by the second ion sensors 173, 174 and 175 is higher than a preset reference ionic conductivity (e.g., 0.1 μS / cm), the first three-way valve 162 can be controlled so that the liquid reactive fluid separated by the first gas-liquid separator 140 can flow along the first bypass line 160 to the upstream side of the first filter section 132, instead of being supplied to the water electrolysis reactor 20.

[0103] On the contrary, such as Figure 2 As shown, when the ionic conductivity of the liquid reactive fluid sensed by the second ion sensors 173, 174 and 175 is equal to or lower than a preset reference ionic conductivity (e.g., 0.1 μS / cm), the first three-way valve 162 can be controlled so that the liquid reactive fluid separated by the first gas-liquid separator 140 is supplied to the water electrolysis reactor 20 instead of the first bypass line 160, and the liquid reactive fluid can be used as water supplied to the water electrolysis reactor 20.

[0104] As described above, in the embodiments of this disclosure, the liquid reaction fluid separated by the first gas-liquid separator 140 selectively flows to the upstream side of the first filter section 132 and is not supplied to the water electrolysis reactor 20. Therefore, it is possible to obtain the beneficial effects of ensuring the quality of the reaction fluid to be supplied to the water electrolysis reactor 20, improving the recyclability of the reaction fluid, and improving durability and stability.

[0105] This is based on the fact that when low-quality reactive fluids (e.g., liquid reactive fluids with high ionic conductivity) are supplied to the water electrolyzer 20, the performance, durability, and stability of the water electrolyzer 20 deteriorate. In embodiments of this disclosure, when the ionic conductivity of the liquid reactive fluid separated by the first gas-liquid separator 140 is higher than a reference ionic conductivity (e.g., 0.1 μS / cm), the liquid reactive fluid flows along the first bypass line 160 to the upstream side of the first filter section 132 instead of being supplied to the water electrolyzer 20, and is subsequently reprocessed (deionized during repeated circulation through the first filter section). Therefore, the beneficial effects of ensuring the quality of the reactive fluid supplied to the water electrolyzer 20, improving the recyclability of the reactive fluid, and improving durability and stability can be obtained.

[0106] In addition, according to the embodiments of this disclosure, it is possible to obtain the beneficial effects of extending the lifespan of the water electrolysis reactor 20 and minimizing the degradation of the durability and stability of the water electrolysis reactor 20 caused by supplying low-quality reaction fluid to the water electrolysis reactor 20.

[0107] According to an exemplary embodiment of this disclosure, when a preset reference time (e.g., 30 minutes) has elapsed after the flow of the liquid reaction fluid has switched from the downstream side of the first gas-liquid separator 140 to the upstream side of the first gas-liquid separator 140, the first filter section 132 can be replaced when the ionic conductivity of the liquid reaction fluid detected by the second ion sensors 173, 174 and 175 is equal to or higher than the preset reference ionic conductivity.

[0108] Specifically, when the time for replacing the first filter section 132 is reached (in the state where a reference time has passed since the flow of the liquid reaction fluid was switched to the upstream side of the first gas-liquid separator 140, and the ionic conductivity of the liquid reaction fluid is higher than the reference ionic conductivity), the alarm generation section (not shown) generates a visual alarm signal (e.g., a notification window on the control program screen) or an audible alarm signal to allow the operator to identify the end of the life of the first filter section 132 and thus allow the operator to replace the first filter section 132 that has reached the end of its life in a timely manner.

[0109] According to an exemplary embodiment of the present disclosure, the electrochemical system 10 may include: a discharge fluid discharge line 210 connected to the cathode 24 and configured to discharge fluid discharged from the cathode 24; a second gas-liquid separator 220 disposed in the discharge fluid discharge line 210 and configured to separate the discharged fluid into a gaseous discharge fluid and a liquid discharge fluid; and a second circulation line 230 configured to connect the second gas-liquid separator 220 and the reaction fluid supply line 130 and configured to circulate the liquid discharge fluid to the reaction fluid supply line 130.

[0110] The discharge fluid line 210 is configured to discharge fluid (e.g., hydrogen + water) discharged from the cathode 24.

[0111] The discharge fluid line 210 may have various structures capable of discharging discharged fluid. This disclosure is not limited or restricted by the structure and shape of the discharge fluid line 210.

[0112] For example, the discharge fluid line 210 may be defined as a generally straight shape. According to another embodiment of this disclosure, the discharge fluid line may be defined as a curved shape or other shapes.

[0113] Furthermore, the discharge fluid line 210 may be equipped with various types of auxiliary devices, such as a pump (not shown) configured to force the discharged fluid to move along the discharge fluid line 210 and a valve (not shown) configured to selectively open or close the discharge fluid line 210. This disclosure is not limited or restricted by the type or number of auxiliary devices.

[0114] The second gas-liquid separator 220 is connected to the discharge fluid discharge line 210 and is configured to separate the discharge fluid discharged from the cathode 24 into a gaseous discharge fluid (e.g., hydrogen) and a liquid discharge fluid (water).

[0115] Various separation devices capable of separating discharged fluid into gaseous and liquid discharged fluids can be used as the second gas-liquid separator 220. This disclosure is not limited or restricted by the type and structure of the second gas-liquid separator 220.

[0116] For example, the second gas-liquid separator 220 may be provided in the form of a hollow box. For example, a discharge fluid line 210 may be connected to approximately the central portion of the second gas-liquid separator 220. A second discharge line 222 may be located approximately at the lower end of the second gas-liquid separator 220 and configured to selectively discharge the liquid discharge fluid from the second gas-liquid separator 220 to the outside. Furthermore, a level sensor (not shown) may be located in the second gas-liquid separator 220 and configured to detect the level of the liquid discharge fluid.

[0117] The second circulation line 230 can be configured to connect the second gas-liquid separator 220 and the reaction fluid supply line 130. The liquid discharge fluid separated by the second gas-liquid separator 220 can circulate along the second circulation line 230 back to the reaction fluid supply line 130.

[0118] For example, the second circulation line 230 can be connected to the reaction fluid supply line 130 via the reaction fluid storage section 120. According to another embodiment of this disclosure, the second circulation line can be directly connected to the reaction fluid supply line.

[0119] The second circulation line 230 can have various structures that enable it to connect the second gas-liquid separator 220 and the reaction fluid supply line 130. This disclosure is not limited or restricted by the structure and shape of the second circulation line 230.

[0120] In the following text, it will be described that the second circulation line 230 is connected to the side of the second gas-liquid separator 220 (based on...). Figure 1 According to another embodiment of this disclosure, the circulation line may be connected to the upper part or other part of the second gas-liquid separator.

[0121] Specifically, the inlet end of the second circulation line 230 can be connected to the second gas-liquid separator 220, such that the inlet end of the second circulation line 230 is positioned below the liquid level of the liquid discharge fluid separated by the second gas-liquid separator 220.

[0122] According to an exemplary embodiment of the present disclosure, the electrochemical system 10 may include a second filter section 232 disposed in a second circulation line 230 and configured to filter out discharged fluid.

[0123] The second filter section 232 is configured to filter the liquid discharge fluid supplied along the second circulation line 230 to the reaction fluid supply line 130.

[0124] Various ion filters capable of filtering out ions and foreign matter (impurities) contained in the liquid discharge fluid can be used as the second filter section 232. This disclosure is not limited or restricted by the type and characteristics of such ion filters. For example, pre-filters, carbon filters, RO membrane filters, ion exchange resins, UV lamps, etc., can be used as the second filter section 232.

[0125] For reference, in embodiments of the present invention, an example is described where the second filter section 232 includes a single ion filter. However, according to another embodiment of this disclosure, the second filter section can be configured by connecting multiple ion filters in parallel or in series.

[0126] According to an exemplary embodiment of the present disclosure, the electrochemical system 10 may include a discharge fluid storage section 240 disposed in a second circulation line 230 downstream of a second filter section 232 (e.g., between the second filter section and the reaction fluid storage section) and configured to store liquid discharge fluid.

[0127] The discharge fluid storage unit 240 may have various structures capable of storing discharge fluid. This disclosure is not limited or restricted by the structure and shape of the discharge fluid storage unit 240.

[0128] For example, the discharge fluid storage unit 240 can be configured as a hollow box. The liquid discharge fluid that has passed through the second gas-liquid separator 220 can be temporarily stored in the discharge fluid storage unit 240 before being supplied to the discharge fluid supply line.

[0129] According to an exemplary embodiment of the present disclosure, the electrochemical system 10 may include a second bypass line 250, one end of which is disposed downstream of the second filter section 232 and connected to the second circulation line 230, and the other end of which is connected to the cathode 24.

[0130] The second bypass line 250 is configured to allow the liquid discharge fluid separated by the second gas-liquid separator 220 to flow selectively to the cathode 24, instead of being supplied to the reaction fluid supply line 130.

[0131] More specifically, one end of the second bypass line 250 is disposed between the second filter section 232 and the discharge fluid storage section 240 and connected to the second circulation line 230, and the other end of the second bypass line 250 is connected to the cathode 24 of the water electrolysis reactor 20.

[0132] Depending on the required conditions and design specifications, the second bypass line 250 can have various structures. This disclosure is not limited or restricted by the structure and shape of the second bypass line 250. For example, the second bypass line 250 may have a generally straight shape. According to another embodiment of this disclosure, the second bypass line may have a curved shape or other shapes.

[0133] According to an exemplary embodiment of the present disclosure, the electrochemical system 10 may include a second three-way valve 252 disposed in a second circulation line 230 and connected to one end of a second bypass line 250.

[0134] Various three-way valves that allow the liquid discharge fluid supplied from the second gas-liquid separator 220 to the reaction fluid supply line 130 to flow selectively to the cathode 24 can be used as the second three-way valve 252. This disclosure is not limited or restricted by the type and structure of the second three-way valve 252.

[0135] For example, the second three-way valve 252 may have the same or similar structure as the first three-way valve 162 described above.

[0136] According to an exemplary embodiment of this disclosure, the electrochemical system 10 may include third ion sensors 261 and 262, which are disposed in at least one of the discharge fluid line 210 and the second circulation line 230 and configured to sense the ionic conductivity of the liquid discharge fluid. A second three-way valve 252 may selectively switch the liquid discharge fluid from the downstream side of the second filter section 232 to the cathode 24 based on the detection results of the third ion sensors 261 and 262.

[0137] In the following description, embodiments in which the third ion sensors 261 and 262 are respectively installed in the second gas-liquid separator 220 and the discharge fluid storage unit 240 will be described.

[0138] Various ion sensors capable of sensing the ionic conductivity of liquid discharged fluids can be used as third ion sensors 261 and 262. This disclosure is not limited or restricted by the type and structure of the third ion sensors 261 and 262.

[0139] Specifically, the movement path of the liquid discharge fluid can be controlled by controlling the second three-way valve 252 based on the detection results of the third ion sensors 261 and 262.

[0140] That is, the second three-way valve 252 can be configured to selectively switch the flow of liquid discharge fluid from the downstream side of the second filter section 232 to the cathode 24 based on the results detected by the third ion sensors 261 and 262.

[0141] For example, refer to Figure 4If the ionic conductivity of the liquid discharge fluid sensed by the third ion sensors 261 and 262 is higher than the preset reference ionic conductivity (e.g., 0.1 μS / cm), the second three-way valve 252 can be controlled so that the liquid discharge fluid separated by the second gas-liquid separator 220 can flow along the second bypass line 250 to the cathode 24 instead of being supplied to the reaction fluid supply line 130.

[0142] On the contrary, such as Figure 2 As shown, when the ionic conductivity of the liquid discharge fluid sensed by the third ion sensors 261 and 262 is equal to or lower than a preset reference ionic conductivity (e.g., 0.1 μS / cm), the second three-way valve 252 can be controlled such that the liquid discharge fluid separated by the second gas-liquid separator 220 is supplied to the reaction fluid supply line 130 instead of the second bypass line 250, and then the liquid discharge fluid can be used as water supplied to the water electrolysis reactor 20.

[0143] As described above, in the embodiments of this disclosure, the second gas-liquid separator 220 separates the effluent from the cathode 24 into a liquid effluent, and supplies the liquid effluent to the reaction fluid supply line 130 and reuses it as water to be supplied to the water electrolysis reactor 20. Therefore, the advantageous effects of improved recyclability of the reaction fluid and reduced consumption of the reaction fluid can be achieved.

[0144] Furthermore, in embodiments of this disclosure, when the quality of the liquid discharge fluid deteriorates (ionic conductivity increases), the liquid discharge fluid flows to the cathode 24 instead of being supplied to the reaction fluid supply line 130. Therefore, the advantageous effects of ensuring the quality of the reaction fluid supplied to the water electrolysis reactor 20 and improving durability and stability can be achieved.

[0145] That is, when the ionic conductivity of the liquid discharge fluid separated by the second gas-liquid separator 220 is higher than the reference ionic conductivity (e.g., 0.1 μS / cm), the liquid discharge fluid flows along the second bypass line 250 to the cathode 24 instead of being supplied to the reaction fluid supply line 130, and then the liquid discharge fluid is reprocessed (deionized during repeated circulation through the second filter section). Therefore, the beneficial effects of ensuring the quality of the reaction fluid supplied to the water electrolysis reactor 20, improving the recyclability of the reaction fluid, and improving durability and stability can be obtained.

[0146] Furthermore, in embodiments of this disclosure, the liquid discharge fluid passes through the cathode 24 when it is repeatedly circulated through the second filter section 232 and reprocessed. Therefore, the cathode 24 can be flushed (cleaned) using the liquid discharge fluid without the need for a separate flushing device.

[0147] According to an exemplary embodiment of this disclosure, when a preset reference time (e.g., 30 minutes) has elapsed after the flow of the liquid discharge fluid has switched from the downstream side of the second filter section 232 to the cathode 24, the second filter section 232 may be replaced when the ionic conductivity of the liquid discharge fluid detected by the third ion sensors 261 and 262 is equal to or higher than the preset reference ionic conductivity.

[0148] Specifically, when the time for replacing the second filter section 232 is reached (in the case where the ionic conductivity of the liquid discharge fluid is higher than the reference ionic conductivity after a reference time has elapsed since the flow of the liquid discharge fluid was switched to the anode 22), the alarm generation section (not shown) generates a visual alarm signal (e.g., a notification window on the control program screen) or an audible alarm signal to allow the operator to identify the end of the life of the second filter section 232 and thus allow the operator to replace the second filter section 232 that has reached the end of its life in a timely manner.

[0149] According to the embodiments of the present disclosure described above, it is possible to obtain the beneficial effects of ensuring the performance of the water electrolysis reactor and improving its durability and stability.

[0150] Specifically, according to embodiments of this disclosure, low-quality reactive fluid (e.g., reactive fluid with high ionic conductivity) flows along a bypass line to a circulation line instead of being supplied to the water electrolyzer, and then the low-quality reactive fluid is reprocessed (e.g., deionized). Therefore, the advantageous effects of ensuring the quality of the reactive fluid supplied to the water electrolyzer, improving the recyclability of the reactive fluid, and improving durability and stability can be obtained.

[0151] Furthermore, according to embodiments of this disclosure, it is possible to obtain the beneficial effects of extending the lifespan of the water electrolyzer and minimizing the degradation of the durability and stability of the water electrolyzer caused by supplying low-quality reactive fluid to the water electrolyzer.

[0152] Furthermore, according to embodiments of this disclosure, the beneficial effects of improving the quality and recyclability of the reaction fluid and reducing the amount of reaction fluid used can be obtained.

[0153] Specifically, according to embodiments of this disclosure, the effluent discharged from the cathode can be reused as a reaction fluid, which can improve the recyclability of the reaction fluid and reduce the amount of reaction fluid used.

[0154] Furthermore, according to embodiments of this disclosure, the cathode can be flushed (cleaned) using a drain fluid without the need for a separate flushing device.

[0155] While embodiments have been described above, they are merely illustrative and not intended to limit this disclosure. Those skilled in the art will understand that various modifications and applications not described above can be made to these embodiments without departing from their inherent characteristics. For example, individual components specifically described in the embodiments may be modified and then implemented. Furthermore, it should be understood that differences related to modifications and applications are included within the scope of this disclosure as defined by the appended claims.

Claims

1. An electrochemical system, comprising: A water electrolysis reactor includes an anode and a cathode; A reaction fluid supply line is configured to supply reaction fluid to the anode; A first gas-liquid separator is located in the reaction fluid supply line and is configured to separate the reaction fluid into a gaseous reaction fluid and a liquid reaction fluid. A first filter section is located in the reaction fluid supply line, upstream of the first gas-liquid separator, and is configured to filter the reaction fluid. A first circulation line is configured to connect the first gas-liquid separator and the anode, and to circulate the liquid reaction fluid passing through the anode to the first gas-liquid separator. as well as A first bypass line, one end of which is located between the first gas-liquid separator and the water electrolysis reactor and connected to the reaction fluid supply line, and the other end of which is located upstream of the first filter section and connected to the reaction fluid supply line.

2. The electrochemical system according to claim 1, comprising: A first ion sensor, located in the reaction fluid supply line, is arranged upstream of the first gas-liquid separator and configured to sense the ionic conductivity of the reaction fluid. The operation of the water electrolysis reactor is configured to be selectively controlled based on the detection results of the first ion sensor.

3. The electrochemical system according to claim 1, comprising: The first three-way valve is located in the reaction fluid supply line and connected to one end of the first bypass line.

4. The electrochemical system according to claim 3, comprising: A second ion sensor is located in at least one of the reaction fluid supply line and the first circulation line, and is configured to sense the ionic conductivity of the liquid reaction fluid. The first three-way valve is configured to selectively switch the flow of the liquid reaction fluid from the downstream side of the first gas-liquid separator to the upstream side of the first gas-liquid separator based on the detection result of the second ion sensor.

5. The electrochemical system according to claim 4, wherein, When a preset reference time has elapsed after the flow of the liquid reaction fluid has switched from the downstream side of the first gas-liquid separator to the upstream side of the first gas-liquid separator, and when the ionic conductivity of the liquid reaction fluid detected by the second ion sensor is equal to or higher than the preset reference ionic conductivity, the first filter section is replaced.

6. The electrochemical system according to claim 1, comprising: A discharge fluid line is connected to the cathode and configured to discharge discharge fluid from the cathode; A second gas-liquid separator is located in the discharge fluid discharge line and is configured to separate the discharge fluid into a gaseous discharge fluid and a liquid discharge fluid. as well as The second circulation line is configured to connect the second gas-liquid separator and the reaction fluid supply line, and to circulate the liquid discharge fluid to the reaction fluid supply line.

7. The electrochemical system according to claim 6, comprising: A reaction fluid storage unit is located in the reaction fluid supply line, arranged upstream of the first filter unit, and configured to store the reaction fluid; as well as A pretreatment filter section, located in the reaction fluid supply line, is arranged upstream of the reaction fluid storage section and is configured to filter the reaction fluid. The second circulation pipeline is connected to the reaction fluid storage unit.

8. The electrochemical system according to claim 6, comprising: The second filter section is located in the second circulation line and is configured to filter the liquid discharge fluid.

9. The electrochemical system according to claim 8, comprising: A second bypass line, one end of which is located downstream of the second filter section and connected to the second circulation line, and the other end of which is connected to the cathode.

10. The electrochemical system according to claim 9, comprising: The second three-way valve is located in the second circulation line and connected to one end of the second bypass line.

11. The electrochemical system according to claim 10, comprising: A third ion sensor is located in at least one of the discharge fluid line and the second circulation line and is configured to sense the ionic conductivity of the liquid discharge fluid. The second three-way valve selectively switches the flow of the liquid discharge fluid from the downstream side of the second filter section to the cathode based on the detection result of the third ion sensor.

12. The electrochemical system according to claim 11, wherein, When a preset reference time has elapsed after the flow of the liquid discharged fluid has switched from the downstream side of the second filter section to the cathode, and when the ionic conductivity of the liquid discharged fluid detected by the third ion sensor is equal to or higher than the preset reference ionic conductivity, the second filter section is replaced.

13. The electrochemical system according to claim 8, comprising: The discharge fluid storage section is located in the second circulation pipeline, arranged downstream of the second filter section, and is configured to store the liquid discharge fluid.

14. An electrochemical system comprising: A water electrolysis reactor includes an anode and a cathode; A reaction fluid supply line is configured to supply reaction fluid to the anode; A first gas-liquid separator is located in the reaction fluid supply line and is configured to separate the reaction fluid into a gaseous reaction fluid and a liquid reaction fluid; A first filter section is located in the reaction fluid supply line, upstream of the first gas-liquid separator, and is configured to filter the reaction fluid. A first circulation line is configured to connect the first gas-liquid separator and the anode, and to circulate the liquid reaction fluid passing through the anode to the first gas-liquid separator. A reaction fluid storage unit is located in the reaction fluid supply line, arranged upstream of the first filter unit, and configured to store the reaction fluid; A first ion sensor is located upstream of the first gas-liquid separator in the reaction fluid supply line and is configured to detect the ionic conductivity of the reaction fluid. A second ion sensor is located in at least one of the reaction fluid supply line and the first circulation line, and is configured to detect the ionic conductivity of the liquid reaction fluid. The electrochemical system further includes a control system configured to selectively stop the operation of the water electrolysis reactor based on the ionic conductivity detected by the first ion sensor and the second ion sensor.

15. The electrochemical system according to claim 14, wherein, The control system is configured to replace the first filter section when a preset reference time has elapsed after the flow of the liquid reaction fluid has switched from the downstream side of the first gas-liquid separator to the upstream side of the first gas-liquid separator, and when the ionic conductivity of the liquid reaction fluid detected by the second ion sensor is equal to or higher than the preset reference ionic conductivity.

16. The electrochemical system according to claim 14, wherein, The control system is configured to selectively stop the operation of the water electrolysis reactor when the ionic conductivity of the reaction fluid exceeds a predetermined threshold.

17. The electrochemical system according to claim 14, wherein, The reaction fluid storage section is configured to store the reaction fluid before supplying it to the first filter section.

18. An electrochemical system comprising: A water electrolysis reactor includes an anode and a cathode; A reaction fluid supply line is configured to supply reaction fluid to the anode; A first gas-liquid separator is located in the reaction fluid supply line and is configured to separate the reaction fluid into a gaseous reaction fluid and a liquid reaction fluid; A first filter section is located in the reaction fluid supply line, upstream of the first gas-liquid separator, and is configured to filter the reaction fluid. A first circulation line is configured to connect the first gas-liquid separator and the anode, and to circulate the liquid reaction fluid passing through the anode to the first gas-liquid separator. A second circulation line is configured to connect a second gas-liquid separator and the reaction fluid supply line, wherein the second gas-liquid separator is located in the discharge fluid discharge line connected to the cathode and is configured to separate the discharge fluid from the cathode into a gaseous discharge fluid and a liquid discharge fluid. The electrochemical system further includes a filtration mechanism in the second circulation line to maintain the ionic purity of the liquid discharge fluid.

19. The electrochemical system according to claim 18, wherein, The electrochemical system further includes: A first ion sensor is located upstream of the first gas-liquid separator in the reaction fluid supply line and is configured to detect the ionic conductivity of the reaction fluid. A second ion sensor is located in at least one of the reaction fluid supply line and the first circulation line, and is configured to detect the ionic conductivity of the liquid reaction fluid. An alarm or notification is triggered when the ionic conductivity detected by the first ion sensor or the second ion sensor exceeds a predetermined threshold.

20. The electrochemical system according to claim 18, further comprising: A reaction fluid storage unit is located in the reaction fluid supply line, arranged upstream of the first filter unit, and configured to store the reaction fluid.

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