METHOD FOR IMPROVING EFFICIENCY OF WATER ELECTROLYSIS SYSTEM, APPARATUS AND SYSTEM THEREFOR

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority to Korean Patent Application No. 10-2024-0137124, filed with the Korean Intellectual Property Office on Oct. 8, 2024, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a water electrolysis system, and more particularly, to a technology for improving an efficiency of a water electrolysis system by utilizing a triboelectric effect.

BACKGROUND

Carbon neutrality is currently a prominent topic worldwide.

Major economies are seeking ways to expand power production by using renewable energy instead of traditional fossil fuels.

A green energy system is a system that uses energy obtained through renewable energy, such as wind, hydro, tidal, and solar power, as electric energy and hydrogen energy.

Among them, green hydrogen is evaluated as the ultimate eco-friendly energy because it does not emit any greenhouse gases at all from the production stage, and hydrogen, which is emerging as an alternative energy on a global scale, is largely divided into gray hydrogen, blue hydrogen, and green hydrogen depending on the production method.

Gray hydrogen is hydrogen produced by reforming natural gas, and although it may be mass-produced and has low production costs, it generates a large amount of greenhouse gases.

Blue hydrogen refers to hydrogen that reduces emission of greenhouse gases by capturing or storing greenhouse gases produced during a gray hydrogen production process.

Green hydrogen is hydrogen produced by electrolyzing water by using renewable energy power and does not emit any greenhouse gases from the production stage but has a low economic feasibility due to high production costs.

Recently, research on water electrolysis devices for production of green hydrogen has been actively conducted, but for green hydrogen to be competitive as an energy carrier, the unit cost of hydrogen production has to be reduced., and an amount of electricity required for electrolysis and the unit cost of a water electrolysis stack are currently high, so that improvement of a power efficiency and reduction of costs are required.

SUMMARY

The present disclosure has been made to solve the aforementioned problems occurring in the prior art, while maintaining the advantages achieved by the prior art.

An aspect of the present disclosure provides a method for improving an efficiency of a water electrolysis system, and a system therefor.

An aspect of the present disclosure also provides method for improving an efficiency of a water electrolysis system, and a system therefor, by which a power efficiency for production of hydrogen may be improved by utilizing additional electric power through circulation of water, by designing a pipe for circulation of water in a water electrolysis system with a structure that may utilize a triboelectric effect.

An aspect of the present disclosure also provides a water electrolysis system that may continuously produce additional electric power by applying a contact electrification pipe as a pipe of an anode, through which water continuously circulates in the water electrolysis system.

The technical problems to be solved by the present disclosure are not limited to the aforementioned problems, and any other technical problems not mentioned herein will be clearly understood from the following description by those skilled in the art to which the present disclosure pertains.

According to an aspect of the present disclosure, a water electrolysis system includes a stack, a power source that supplies a voltage to an anode and a cathode of the stack, and a contact electrification pipe connected to the anode such that a fluid circulates therein, and the fluid includes at least water, and electric power generated in the contact electrification pipe is supplied to the power source.

The contact electrification pipe may further include an internal nonconductive layer in contact with the fluid, and a conductive layer disposed on the outer surface of the nonconductive layer.

The nonconductive layer may be formed of any one of materials of polytetrafluoroethylene (PTEF), polydimethylsiloxane (PDMS), and polyethylene (PE).

The conductive layer may be formed of any one of materials of aluminum and copper.

The conductive layers may be alternately disposed at regular intervals on the outskirt of the nonconductive layer.

The conductive layer may be formed by winding an electric wire in a form of a coil on the outskirt of the nonconductive layer.

The stack may further include a power converter that converts AC power generated in the contact electrification pipe to DC power, and the DC power may be used as additional electric power of the power source.

An electric double layer may be formed between the fluid and the contact electrification pipe to generate the electric power as the fluid flows.

The water electrolysis system may further include a circulator that continuously supplies the fluid to the anode through a pump connected to the contact electrification pipe, and filters the fluid discharged from the anode to store the fluid in a water tank.

The water electrolysis system may further include a gas/liquid separator that separates hydrogen from the fluid discharged from the cathode, a third pipe disposed between the cathode and the gas/liquid separator, and a hydrogen tank that stores the separated hydrogen.

According to an aspect of the present disclosure, a method for improving an efficiency of a water electrolysis system includes supplying a fluid constantly to an anode of a stack through a first contact electrification pipe, applying a voltage to the anode and a cathode of the stack through a power source, recovering the fluid discharged from the anode through a second contact electrification pipe, and supplying electric power generated in the first contact electrification pipe and the second contact electrification pipe to the power source as additional electric power of the stack by using a triboelectric effect according to circulation of the fluid, wherein the fluid may further include at least water.

The first and second contact electrification pipes may further include an internal nonconductive layer contacting the fluid, and a conductive layer disposed on an outskirt of the nonconductive layer.

The nonconductive layer may be formed of any one of materials of polytetrafluoroethylene (PTFE), polydimethylsiloxane (PDMS), and polyethylene (PE).

The conductive layer may be formed of any one of materials of aluminum and copper.

The conductive layers may be alternately disposed at regular intervals on the outskirt of the nonconductive layer.

The conductive layer may be formed by winding an electric wire in a form of a coil on the outskirt of the nonconductive layer.

The stack further may include a power converter configured to convert AC power generated in the first and second contact electrification pipes, and the DC power may be utilized as additional power of the stack.

An electric double layer may be formed between the fluid and the first and second contact electrification pipes to generate the electric power as the fluid flows.

The method may further include filtering the recovered fluid to store the fluid in a water tank.

The fluid supplied to the anode passes through a separator provided in the stack to be supplied to the cathode, and the method may further include separating hydrogen from the fluid discharged from the cathode, and storing the separated hydrogen in a hydrogen tank.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the present disclosure will be more apparent from the following detailed description taken in conjunction with the accompanying drawings:

FIG. 1 is a view illustrating a structure and an operation of a general water electrolysis system;

FIG. 2 is a block diagram illustrating a structure of a water electrolysis system according to an embodiment of the present disclosure;

FIG. 3 is a view illustrating a structure and an operation of a water electrolysis system according to an embodiment of the present disclosure;

FIGS. 4 to 5 are views illustrating a structure of a contact electrification pipe and, a process of forming an electric double layer by friction in a pipe according to an embodiment of the present disclosure;

FIG. 6 is a flowchart illustrating a method for improving an efficiency of a water electrolysis system according to an embodiment of the present disclosure; and

FIG. 7 is a view illustrating a computing device according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

Hereinafter, some embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals will be used throughout to designate the same or equivalent components. In describing embodiments of the present disclosure, detailed descriptions associated with well-known functions or configurations will be omitted if they may make subject matters of the present disclosure unnecessarily obscure.

In describing components of embodiments of the present disclosure, the terms first, second, A, B, (a), (b), and the like may be used herein. These terms are only used to distinguish one element from another element, but do not limit the corresponding elements irrespective of the nature, order, or priority of the corresponding elements. Furthermore, unless otherwise defined, all terms including technical and scientific terms used herein are to be interpreted as is customary in the art to which the present disclosure belongs. Such terms as those defined in a generally used dictionary are to be interpreted as having meanings equal to the contextual meanings in the relevant field of art, and are not to be interpreted as having ideal or excessively formal meanings unless clearly defined as having such in the present application.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to FIGS. 1 to 4.

FIG. 1 is a view illustrating a structure and an operation of a general water electrolysis system.

Referring to FIG. 1, a water electrolysis system 100 may largely include a stack 110, and first to third pipes 120 to 140.

The stack 110 may include a power source 111, an anode 112, a cathode 113, a separator (membrane) 114, and first and second catalytic plates 115 and 116.

Water electrolysis is a method of producing hydrogen by electrochemically decomposing water that is supplied to the stack 110.

As illustrated in FIG. 1, the first pipe 120 is a pipe for supplying water to the stack 110.

When the power source 111 is applied and water is continuously supplied to the anode 112 of the stack 110 through the first pipe 120, electrolysis begins. Oxygen is generated at the anode 112, which is the positive (+) electrode, and hydrogen is generated at the cathode 113, which is the negative (−) electrode.

The second pipe 130 is a pipe, through which oxygen generated in the anode 12 and water are discharged, and the third pipe 140 is a pipe, through which hydrogen generated in the cathode 113 and water are discharged.

The water discharged through the second pipe 130 may be recycled via a filter system.

The water supplied to the anode 112 may be delivered over to the cathode 113 through a separator 114, and the water is discharged through the third pipe 140 together with hydrogen generated in the cathode 113.

The water and hydrogen discharged through the third pipe 140 may be separated into liquid and gas through the gas/liquid separator to obtain hydrogen.

In the case of a green energy system, the electric power supplied to the stack 110 may be mainly associated with renewable energy, such as wind power, hydropower, tidal power, and solar power.

FIG. 2 is a block diagram illustrating a structure of a water electrolysis system according to an embodiment of the present disclosure.

Referring to FIG. 2, a water electrolysis system 200 may include at least one of a main power supply part (or a power source) 210, a water electrolysis stack 220, a circulator 230, a hydrogen storage part 240, a contact electrification pipe part 250, and a contact electrification power conversion part 260.

In addition to the development of sustainable eco-friendly energy, energy harvesting, which may solve the problem of supplying power sources for various devices, has recently attracted great attention. The energy harvesting technology is a technology that harvests electrical energy from energy sources that are discarded in real life, such as light, heat, and vibration.

Energy harvesting was selected as one of the top 10 promising technologies by MIT and 45 innovative technologies that will shake the world by Popular Science that is an American science magazine, and research are being actively conducted around the world to preempt this technology.

Among the various energy harvesting technologies, there is a triboelectric power generation element that generates electricity by combining contact electrostatic induction and electrostatic induction.

The contact Electrification (or triboelectrification) refers to a phenomenon in which the surfaces of two objects become charged with positive and negative charges, respectively, when they are separated after contact.

Triboelectricity is a type of contact electrification, in which electrons from one object move to another object by frictional energy that is generated when a particular material rubs against another material.

A triboelectric effect (also known as triboelectric charging) is a type of contact electrification process, in which a specific material is electrically charged after being separated from other materials in contact.

An intensity of the triboelectricity may be determined by a frictional coefficient.

The frictional coefficient μ is a ratio of a vertical force “N” that acts on a contact surface and a frictional force “F” that resists to free sliding when two objects are in contact. In the case of an object that is pulled or pushed horizontally, the vertical force “N” is simply a gravitational force (or weight). In the equation μ=F/N, both “F” and “N” are measured in units of force (Newton), and thus, the frictional coefficient is dimensionless. The type and value of the frictional coefficient may vary depending on a material, a surface state, and a type of resistance (static friction or kinetic friction) of the two objects.

Hereinafter, a water electrolysis system that may improve a power efficiency by utilizing a triboelectric effect according to an embodiment of the present disclosure, and a method thereof will be described in detail.

The water electrolysis system 200 according to the present disclosure includes a pipe having a triboelectric effect to secure additional power, so that a power efficiency may be improved.

A main power supply part 210 may supply electric power (or a voltage) to the water electrolysis stack 220.

As illustrated in FIG. 1, the water electrolysis stack 220 has a structure, in which the separator 114 is disposed between the anode 112 and the cathode 113.

The circulator 230 may include a water tank and a circulation pump to be implemented so that water in the water electrolysis stack 220 is supplied and discharged.

The circulator 230 may include a circulation filter for filtering the water discharged from the anode 211.

The hydrogen storage part 240 may include a gas/liquid separator to separate hydrogen from the fluid discharged from the cathode and then store the separated hydrogen in the provided hydrogen tank.

The contact electrification pipe part 250 may be designed and implemented to have a triboelectric effect to be implemented to secure additional electric power. The detailed configuration and features of the contact electrification pipe part 250 will become more apparent through the description of FIGS. 3 to 5, which will be described later.

The contact electrification power conversion part 260 may rectify the electric power generated by the contact electrification pipe part 250 to convert the rectified electric power to electric power that is required for driving the water electrolysis stack 220.

As described above, the water electrolysis system 200 according to the present disclosure may generate additional electric power through the contact electrification pipe part 250 and use it as additional electric power for driving the water electrolysis stack 220 to improve a power efficiency of the system.

FIG. 3 is a view illustrating a structure and an operation of a water electrolysis system according to an embodiment of the present disclosure.

Referring to FIG. 3, a water electrolysis system 300 may include a stack 310, a water tank 320, a circulator 330, a gas/liquid separator 340, a hydrogen tank 350, first and second contact electrification pipes 360 and 370, a third pipe 380, and an additional power supply line 390.

The stack 310 may include a power source 311, an anode 312, a cathode 313, a separator (membrane) 314, first and second catalytic plates 315 and 316, and a power converter 317.

In an embodiment, the first and second contact electrification pipes 360 and 370 may be implemented to have a triboelectric effect, and sides of the first and second contact electrification pipes 360 and 370 may be connected to the anode 312, and opposite sides of the first and second contact electrification pipes 360 and 370 may be connected to the circulator 330.

For example, pipes of a material, such as polytetrafluoroethylene (PTFE) having a higher frictional coefficient than those of general pipes may be used for the first and second contact electrification pipes 360 and 370, but the present disclosure is not limited thereto, and pipes of a material of polydimethylsiloxane (PDMS) or polyethylene (PE) having a higher or lower frictional coefficient may be used depending on a design of an ordinary person skilled in the art.

An electric double layer due to friction generated from an inner wall of the pipe when the water flows in the first and second contact electrification pipes 360 and 370 may be formed. An AC voltage may be generated as triboelectricity is generated and disappears by winding a conductive material, for example, copper, aluminum, and the like around outer walls of the first and second contact electrification pipes 360 and 370 at a specific interval. The generated AC voltage may be transmitted to the power converter 317 through the additional power supply line 390 to be converted into a DC voltage through an internal rectifier and then supplied as the additional electric power of the stack 310.

The third pipe 380 may be implemented as a general pipe having no triboelectric effect, and one side of the third pipe 380 may be connected to the cathode 313 and an opposite side of the third pipe 380 may be connected to the gas/liquid separator 340.

The circulator 330 may control the water stored in the water tank 320 to be continuously supplied to the anode 312 of the stack 310 through a first pipe 360 by driving a circulation pump (not illustrated) provided, and may pass through the filter (not illustrated) provided to supply purified water to the water tank 320 when the water supplied to the anode 312 circulates and is introduced through a second pipe 370.

The water that flows through the second pipe 370 includes a large amount of oxygen, and the circulator 330 according to an embodiment may further include a gas/liquid separator for removing oxygen contained in the water introduced through the second pipe 370 and supplying the water to the water tank 320.

The water introduced into the anode 312 may be supplied to the cathode 313 through the separator 314.

In the anode 312, when a specific voltage or higher is applied from the power source 311 after the filtered water is supplied, the water is electrolyzed to generate oxygen molecules (O²). In the case of hydrogen ions (H⁻) generated through electrolysis in the anode 312, ions may be delivered through the separator 314.

In the cathode 313, hydrogen ions introduced from the anode 312 through the separator 314 are coupled to electrons with the help of the catalyst to form hydrogen molecules (H²).

The gas/liquid separator 340 may separate pure hydrogen from the fluid (water and hydrogen) introduced through the third pipe 380 and supply the separated hydrogen to the hydrogen tank 350. In one embodiment, the separated water may be discharged externally in the form of water vapor. In another embodiment, the water (or water vapor) may be cooled and then returned to the circulator 330 through a separate pipe for recycling.

The electrons (e(−)) generated in the first pipe 360 and the second pipe 370 may be supplied to the power converter 317 of the stack 310 through the additional power supply line 390.

The power converter 317 may rectify the electric power through the provided rectifier and convert the rectified electric power into required power to supply additional electric power to the power source 311.

As described above, the water electrolysis system 300 according to the present disclosure may improve a power efficiency by designing water that constantly circulates around the anode 312 to flow through the contact electrification pipe to produce continuous additional electric power and supply it to the power source 311 of the stack 310.

FIGS. 4 to 5 are views illustrating a structure of a contact electrification pipe and, a process of forming an electric double layer by friction in a pipe according to an embodiment of the present disclosure.

Referring to FIG. 4, drawing number 410 illustrates transverse cross section of contact electrification pipes 360 and 370, and drawing number 420 illustrates longitudinal cross section of the contact electrification pipes 360 and 370.

Referring to reference numeral 410, the contact electrification pipes 360 and 370 may include an internal nonconductive layer 412 and an external conductive layer 411.

The nonconductive layer 412 may be formed of a material that does not conduct electricity, which has a high frictional coefficient, and the conductive layer 411 may be formed of a material that conducts electricity well.

The conductive layer 411 according to an embodiment may be formed by winding an electric wire around the nonconductive layer 412 in a coil form.

When the water flows along the inner wall of the nonconductive layer 412, friction may occur in an area, in which the nonconductive layer 412 contacts the water, and thus, an electric double layer 413 may be formed. That is, the electric double layer 413 may be formed with a water interface interposed between an inner wall of the contact electrification pipes 360 and 370 and the electric double layer 413.

In this case, the electron (e(−)) of the electric double layer 413 is delivered to a load 440 through an electric wire 430 connected to one side of the conductive layer 411, and thus, electric power may be supplied to the load 440.

For example, as illustrated by drawing number 510 of FIG. 5, the conductive layers 411 may be alternately disposed at regular intervals along the outer wall of the nonconductive layer 412, and in this case, as illustrated in drawing number 520, the conductive layer 411 may continuously form a voltage as the water having a polarity flows.

As described above, the present disclosure may improve the power efficiency of the water electrolysis system by utilizing the electrostatic force between the contact electrolysis pipe and the working fluid as water electrolysis power.

FIG. 6 is a flowchart illustrating a method for improving an efficiency of a water electrolysis system according to an embodiment of the present disclosure.

Referring to FIGS. 3 and 6, the water electrolysis system 300 may continuously supply the water to the anode 312 of the stack 310 through the first contact electrification pipe 360 (S610).

The water electrolysis system 300 may apply a voltage to the anode 312 and the cathode 313 of the stack 310 through the power source 311 (S620).

The water electrolysis system 300 may recover the fluid discharged from the anode 312 through the second contact electrification pipe (S630). Here, the fluid includes water and oxygen.

The water electrolysis system 300 may supply the electric power generated by the first electrification pipe 360 and the second electrification pipe 370 to the power source 311 by using the triboelectric effect. Here, the power generated by the first electrification pipe 360 and the second electrification pipe 370 may be AC power, and the water electrolysis system 300 may convert AC power generated by the first electrification pipe 360 and the second electrification pipe 370 to DC power through the provided power converter 317 and may supply the DC power to the power source 311.

FIG. 7 illustrates a computing device according to an embodiment of the present disclosure.

Referring to FIG. 7, a computing system 700 may include at least one of at least one processor 720, a memory 730, a user interface input device 740, a user interface output device 750, a storage 760, and a network interface 770, which are connected to each other through a bus 810.

The processor 720 may be a central processing unit (CPU) or a semiconductor device that processes instructions stored in the memory 730 and/or the storage 760. The memory 730 and the storage 760 may include various types of volatile or nonvolatile storage media. For example, the memory 730 may include a read only memory (ROM) 731 and a random access memory (RAM) 732.

Thus, the operations of the methods (or procedures) or algorithms described in connection with the embodiments disclosed in the specification may be directly implemented with a hardware module, a software module, or a combination of the hardware module and the software module, which is executed by the processor 720. The software module may reside on a storage medium (that is, the memory 730 and/or the storage 760) such as a RAM, a flash memory, a ROM, an EPROM, an EEPROM, a register, a hard disc, a removable disk, and a CD-ROM. As an example, the processor 820 may constitute a part of the above-described water electrolysis system.

The storage medium may be coupled to the processor 720, and the processor 720 may read out information from the storage medium and may write information in the storage medium. Alternatively, the storage medium may be integrated with the processor 720. The processor and the storage medium may reside in an application specific integrated circuit (ASIC). The ASIC may reside in a controller in the vehicle. Alternatively, the processor 720 and the storage medium may reside as separate components in the controller of the vehicle.

The present disclosure may provide a method for improving an efficiency of a water electrolysis system, and a system therefor.

Furthermore, according to the present disclosure, a power efficiency for production of hydrogen may be improved by utilizing additional electric power through circulation of water, by designing a pipe for circulation of water in a water electrolysis system with a structure that may utilize a triboelectric effect.

Furthermore, the present disclosure may provide a water electrolysis system that may continuously produce additional electric power by applying a contact electrification pipe to a pipe of an anode, through which water continuously circulates in the water electrolysis system.

In addition, the present disclosure may provide a water electrolysis system that may reduce the costs of production of hydrogen.

Besides, a variety of effects directly or indirectly understood through the present disclosure may be provided.

The above description is merely an example of the technical idea of the present disclosure, and various modifications and variations may be made by one skilled in the art without departing from the essential characteristic of the present disclosure.

Accordingly, embodiments of the present disclosure are intended to illustrate, not limit, the technical concept of the present disclosure. The scope and spirit of the present disclosure should not be limited by the above embodiments. Rather, the scope of protection of the present disclosure should be defined by the attached claims, and all equivalents thereof should be construed as falling within the scope of the present disclosure.