CN117845251A - Bipolar plate, electrolytic tank and electrolytic water hydrogen production system - Google Patents

Abstract

The present disclosure provides a bipolar plate, an electrolyzer, and a water electrolysis hydrogen production system. The bipolar plate is used for a water electrolysis hydrogen production system and is provided with a first side and a second side which are opposite to each other, a first electrolysis chamber is formed on the first side, a liquid inlet communicated with the first electrolysis chamber is formed on the lower part of the bipolar plate, a first discharge outlet communicated with the first electrolysis chamber and a second discharge outlet communicated with the second side are formed on the upper part of the bipolar plate, a liquid outlet and a backflow outlet which enable the first discharge outlet to be communicated with the first electrolysis chamber are formed on the top wall of the first electrolysis chamber, the liquid outlet and the backflow outlet are adjacently arranged and are mutually separated, a partition plate is arranged in the upper part of the first electrolysis chamber, the partition plate divides the upper part of the first electrolysis chamber into a first chamber and a second chamber, the first chamber is opposite to the liquid outlet and is communicated with the liquid outlet, the second chamber is opposite to the backflow outlet and is communicated with the lower part of the first chamber and the lower part of the second chamber is mutually communicated with each other.

Description

Bipolar plate, electrolytic tank and electrolytic water hydrogen production system

Technical Field

The present disclosure relates to the technical field of hydrogen production by water electrolysis, and more particularly, to a bipolar plate, an electrolytic tank, and a hydrogen production system by water electrolysis.

Background

In recent years, clean energy has been continuously developed. Hydrogen is considered to be the most desirable clean energy source because the product of its combustion is water, is environmentally friendly and generates a large amount of heat. Typically, hydrogen may be produced by an electrolytic water hydrogen production system.

For the water electrolysis hydrogen production system, due to the heat generated in the water electrolysis hydrogen production process, the temperature difference between the electrolyte in the electrolytic tank from the liquid inlet to the liquid outlet is large (the temperature difference is usually 60 ℃ to 70 ℃), which causes uneven heating of various components (such as polar plates, diaphragms, sealing elements and the like) in the electrolytic tank, thus affecting the stability and service life of various components and simultaneously affecting the hydrogen production efficiency. Particularly, the diaphragm in the electrolytic cell, which is affected by the temperature difference of the electrolyte, causes the large-sized (e.g., large-area) development of the electrolytic cell. Furthermore, if an unstable fluctuating power supply is supplied to the plates in the electrolyzer, a further temperature difference between the inlet and outlet will result.

In addition, in the electrolytic water hydrogen production system, it is generally necessary to pump the electrolyte into the electrolytic tank using a pump and to flow the electrolyte in the electrolytic water hydrogen production system, but the pump consumes a large amount of electric power and requires frequent maintenance. In addition, the pump may be subject to corrosion by the electrolyte. Therefore, such a water electrolysis hydrogen production system has high hydrogen production cost and insufficient stability.

Disclosure of Invention

It is therefore an object of the present disclosure to provide a bipolar plate that equalizes the temperature of an electrolyte by self-circulating the electrolyte in a first electrolyte chamber.

It is also an object of the present disclosure to provide an electrolytic cell that can improve the stability and service life of the various components in the electrolytic cell while facilitating the large-scale development of the electrolytic cell and adaptation to fluctuating power supplies.

According to an aspect of the present disclosure, there is provided a bipolar plate for a water electrolysis hydrogen production system and having first and second sides opposite to each other, a first electrolysis chamber formed in the first side of the bipolar plate, a liquid inlet communicating with the first electrolysis chamber formed in a lower portion of the bipolar plate, a first discharge port communicating with the first electrolysis chamber formed in an upper portion of the bipolar plate, and a second discharge port communicating with the second side of the bipolar plate, wherein a liquid outlet and a backflow port communicating the first discharge port with the first electrolysis chamber are formed in a top wall of the first electrolysis chamber, the liquid outlet and the backflow port being adjacently disposed and spaced apart from each other, wherein a partition plate is provided in an upper portion of the first electrolysis chamber, the partition plate dividing the upper portion of the first electrolysis chamber into a first chamber and a second chamber such that the first chamber is opposite to and communicates with the liquid outlet, the second chamber is opposite to and communicates with the backflow port, and the lower portion of the first chamber and the lower portion of the second chamber communicate with each other.

Preferably, the liquid outlets may be provided in plural and spaced apart from each other on the top wall of the first electrolysis chamber.

Preferably, the partition plate may be inclined with respect to the surface of the first side or parallel to the surface of the first side.

Preferably, the distance between the partition plate and the surface of the first side may gradually decrease from top to bottom.

Preferably, a plurality of diverting protrusions may be provided on a portion of the surface of the first side near the liquid inlet.

Preferably, a plurality of flow channels may be formed on a surface of the second side of the bipolar plate, the plurality of flow channels communicating with the second discharge port.

Preferably, a second electrolytic chamber may be formed at the second side of the bipolar plate, the second electrolytic chamber being in communication with the second discharge port and the liquid inlet port.

According to another aspect of the present disclosure, there is provided an electrolytic cell comprising: at least two bipolar plates as described above, stacked with the first sides of the bipolar plates facing in the same direction; a separator disposed between adjacent ones of the at least two bipolar plates; and a seal disposed between the bipolar plate and the separator.

Preferably, a catalytic layer may be provided between the separator and the bipolar plate.

According to another aspect of the present disclosure, there is provided a water electrolysis hydrogen production system including: the electrolytic cell as described above, wherein the membrane is a proton exchange membrane, the first side is an anode side, and the second side is a cathode side; a first gas-liquid separator communicated with the first discharge port and for discharging oxygen; and the second gas-liquid separator is communicated with the second discharge port and is used for discharging hydrogen.

According to another aspect of the present disclosure, there is provided a water electrolysis hydrogen production system including: the electrolytic cell as described above, wherein the membrane is an anion exchange membrane, the first side is a cathode side, and the second side is an anode side; a first gas-liquid separator communicated with the first discharge port and used for discharging hydrogen; and the second gas-liquid separator is communicated with the second discharge port and is used for discharging oxygen.

According to another aspect of the present disclosure, there is provided a water electrolysis hydrogen production system including: the electrolytic cell as described above, wherein the separator is a porous membrane, the first side is a cathode side, and the second side is an anode side; a first gas-liquid separator communicated with the first discharge port and used for discharging hydrogen; and the second gas-liquid separator is communicated with the second discharge port and the liquid inlet and is used for discharging oxygen.

Preferably, the electrolytic water hydrogen production system may further comprise a liquid replenishing tank for replenishing the first gas-liquid separator with electrolyte, wherein the first gas-liquid separator may further be in communication with the liquid inlet, and the first gas-liquid separator may be located higher than the electrolytic tank.

Preferably, the electrolyzed water hydrogen production system may further comprise an ion exchange column and/or a heat exchanger located between the first gas-liquid separator and the liquid inlet.

By employing the bipolar plate according to the present disclosure, it is possible to self-circulate the electrolyte in the first electrolytic chamber and equalize the temperature of the electrolyte in the first electrolytic chamber. In addition, by applying the bipolar plate according to the present disclosure to an electrolytic cell, self-circulation flow of an electrolyte is achieved in the electrolytic cell to equalize the temperature of the electrolyte, which can improve stability and service life of individual components in the electrolytic cell while facilitating large-scale development of the electrolytic cell and adaptation to a fluctuating power supply.

Drawings

The foregoing and other objects, features, and advantages of the disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings in which:

fig. 1 is a perspective view of a bipolar plate according to an embodiment of the present disclosure;

fig. 2 is a plan view of a first side of the bipolar plate of fig. 1;

FIG. 3 is a plan view of a second side of the bipolar plate of FIG. 1;

fig. 4 is a perspective view obtained by cutting away a portion of the bipolar plate in the vertical direction;

FIG. 5 is a top view of the upper portion of the bipolar plate cut away in a horizontal direction to show the fluid outlet and return ports;

FIG. 6 is a schematic structural view of a first water electrolysis hydrogen production system according to the present disclosure;

FIG. 7 is a schematic diagram of a second electrolytic water hydrogen production system according to the present disclosure;

fig. 8 is a schematic structural view of a third water electrolysis hydrogen production system according to the present disclosure.

Detailed Description

Embodiments in accordance with the present disclosure will now be described in detail with reference to the drawings, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout.

Embodiments of the present disclosure provide a bipolar plate 10 for use in a water electrolysis hydrogen production system and having a first side and a second side opposite each other. Fig. 1 is a perspective view of a bipolar plate 10 according to an embodiment of the present disclosure, fig. 2 is a plan view of a first side of the bipolar plate 10 in fig. 1, fig. 3 is a plan view of a second side of the bipolar plate 10 in fig. 1, fig. 4 is a perspective view obtained by cutting away a portion of the bipolar plate 10 in a vertical direction, and fig. 5 is a plan view by cutting away an upper portion of the bipolar plate 10 in a horizontal direction to show a liquid outlet 14 and a return outlet 15. A specific structure of the bipolar plate 10 according to an embodiment of the present disclosure will be described below with reference to fig. 1 to 5.

As shown in fig. 1 to 5, a first electrolytic chamber is formed at a first side of the bipolar plate 10, a liquid inlet 11 communicating with the first electrolytic chamber is formed at a lower portion of the bipolar plate 10, a first discharge port 12 communicating with the first electrolytic chamber and a second discharge port 13 communicating with a second side of the bipolar plate 10 are formed at an upper portion of the bipolar plate 10, and the first discharge port 12 and the second discharge port 13 can be used to discharge a corresponding one of hydrogen and oxygen generated by the electrolytic water hydrogen production system. Further, a liquid outlet 14 and a return outlet 15 for communicating the first discharge port 12 with the first electrolytic chamber are formed in the top wall of the first electrolytic chamber, and the liquid outlet 14 and the return outlet 15 are disposed adjacently and are spaced apart from each other. In addition, a partition plate 16 is provided in the upper portion of the first electrolytic chamber, the partition plate 16 partitions the upper portion of the first electrolytic chamber into a first chamber and a second chamber such that the first chamber is opposed to and communicates with the liquid outlet 14, the second chamber is opposed to and communicates with the return port 15, and the lower portion of the first chamber and the lower portion of the second chamber communicate with each other.

By using the above-described bipolar plate 10 of the present disclosure in a water electrolysis hydrogen production system, electrolyte at the liquid inlet 11 of the bipolar plate 10 flows upward from the liquid inlet 11 through the lower portion of the first electrolysis chamber, the first chamber and the liquid outlet 14 due to a bubble effect (e.g., bubbles caused by generated oxygen or hydrogen gas), and then reaches the first discharge outlet 12. Subsequently, there will be a portion of the electrolyte and oxygen in the first discharge port 12 flowing downward (e.g., the upward flowing electrolyte, pushed by gravity and/or by the bubble effect, hits the upper wall of the first discharge port 12) through the return port 15 and the second chamber and then returns to the lower part of the first electrolyte chamber and the liquid inlet 11 to mix with the electrolyte at the lower part of the first electrolyte chamber and the liquid inlet 11. By allowing the electrolyte to self-circulate in the manner described above, the temperature of the electrolyte in the first electrolytic chamber can be equalized (e.g., the temperature difference of the electrolyte between the liquid inlet 11 and the first outlet 12 is made within an acceptable range), thereby improving the stability and service life of the individual components in an electrolytic cell (e.g., electrolytic cell 100 to be described below) of the water-electrolytic hydrogen production system, while facilitating the large-scale development of the electrolytic cell and the adaptation to a fluctuating power supply.

Further, the remaining part of the electrolyte and oxygen in the first discharge port 12 except for the part returned to the lower part of the first electrolytic chamber and the liquid inlet 11 is discharged to the outside of the electrolytic bath through the first discharge port 12. The flow process of the electrolyte and oxygen discharged to the outside of the electrolytic cell will be described later.

In addition, although it is described above that the liquid inlet 11 is formed at the lower portion of the bipolar plate 10 and the first and second discharge ports 12 and 13 are formed at the upper portion of the bipolar plate 10, the present disclosure is not limited thereto, and the liquid inlet, the first discharge port and the second discharge port may be formed at any position on the bipolar plate as required, as long as the self-circulation flow of the electrolyte as described above and the discharge of hydrogen and oxygen gas can be achieved. In addition, the number and shape of the liquid inlet, the first discharge port, the second discharge port, the liquid outlet, and the return port are not limited to those shown in fig. 1 to 5. In addition, although the bipolar plate 10 is shown in fig. 1 and 5 as having a rectangular cross-section in the thickness direction, the present disclosure is not limited thereto, and the cross-section of the bipolar plate in the thickness direction may also be trapezoidal, circular, pentagonal, hexagonal, or the like.

As shown in fig. 1, the first electrolysis chamber may be a recess formed on a first side of the bipolar plate 10 and the top wall of the first electrolysis chamber may be the top wall of the recess. However, embodiments of the present disclosure are not limited thereto, the first electrolysis chamber may also be a flat surface of the bipolar plate, and the top wall of the first electrolysis chamber may be a protrusion protruding from the flat surface, the flat surface and protrusion forming a chamber by mating with other components in the electrolysis cell.

Further, as shown in fig. 1 and 5, the liquid outlet 14 may be plural and the plural liquid outlets 14 may be provided on the top wall of the first electrolytic chamber spaced apart from each other. In this case, the portion of the top wall of the first electrolytic chamber other than the plurality of liquid outlets 14 may serve to block the electrolyte flowing from the liquid inlet 11 toward the liquid outlet 14, thereby allowing the blocked electrolyte to flow back toward the liquid inlet 11, which can make the temperature of the electrolyte in the first electrolytic chamber more uniform.

Furthermore, the separator plate 16 may be inclined with respect to the surface of the first side of the bipolar plate 10 or parallel to the surface of the first side. The surface of the first side of the bipolar plate 10 may refer to the surface of the bipolar plate 10 in the thickness direction. The separator 16 may be disposed facing a surface of the first side of the bipolar plate 10. Furthermore, the angle between the partition plate 16 and the surface of the first side may be between 0 ° and 15 °. Further, the distance between the partition plate 16 and the surface of the first side gradually decreases from top to bottom so that the upper end opening of the second chamber can receive most of the electrolyte returned from the return port 15, and the returned electrolyte accelerates downward flow due to gravity and due to the gradual decrease in the sectional area of the second chamber, thereby mixing with the electrolyte in the lower portion of the first electrolyte chamber and the liquid inlet 11 with a large flow impact force.

As shown in fig. 1 and 2, a plurality of diverting protrusions 17 may be provided on a portion of the surface of the first side of the bipolar plate 10 near the liquid inlet 11, and the diverting protrusions 17 may change the flow direction of the electrolyte so that the electrolyte flows upward from the liquid inlet 11 and downward from the lower portion of the first electrolytic chamber to the liquid inlet 11 in a uniform manner. The uniform flow of electrolyte will make the temperature of the electrolyte in the first electrolytic chamber more uniform.

The structure of the first side of the bipolar plate 10 is described above, while the second side of the bipolar plate 10 may have a different structure or a similar structure to the first side. As shown in fig. 3, the second side of the bipolar plate 10 has a different structure than the first side. Specifically, a plurality of flow channels 18 are formed on the surface of the second side of the bipolar plate 10, and the plurality of flow channels 18 communicate with the second discharge port 13. Furthermore, the plurality of flow channels 18 on the second side of the bipolar plate 10 may be independent of each other (in the form of a straight channel) or connected to each other (in the form of a serpentine channel). However, the present disclosure is not limited thereto, and the second side of the bipolar plate may have a similar structure to the first side, for example, a second electrolytic chamber may be formed at the second side of the bipolar plate 10, and the second electrolytic chamber may communicate with the second discharge port 13 and the liquid inlet port 11. In addition, the second side of the bipolar plate may also have a runnerless structure.

The present disclosure also provides an electrolytic cell 100, the electrolytic cell 100 comprising: at least two bipolar plates 10 as described above are stacked in such a manner that the first sides of the bipolar plates 10 face in the same direction; a separator 20 disposed between adjacent two bipolar plates 10 of the at least two bipolar plates 10; a seal (not shown) is disposed between the bipolar plate 10 and the separator 20. By the cooperation of the bipolar plate 10, the diaphragm 20 and the seal, a first discharge path from the liquid inlet 11 to the first discharge port 12, a second discharge path from the second side of the bipolar plate 10 to the second discharge port 13, and a circulation path of the electrolyte can be realized in the electrolytic cell. The first discharge path passes through the liquid inlet 11, the diverting protrusion 17, the lower part of the first electrolytic chamber, the first chamber and the liquid outlet 14 in this order, and finally reaches the first discharge outlet 12. The second exhaust path may pass through the second side of the bipolar plate 10 and the plurality of flow channels 18 in sequence, ultimately to the second exhaust port 13. The circulation path of the electrolyte includes, in addition to the first discharge path, a return path that passes through the first discharge port 12, the return port 15, the second chamber, and the lower portion of the first electrolytic chamber in this order, and finally reaches the liquid inlet 11.

In the above-described electrolytic cell 100, the electrolyte can circulate along the circulation path of the electrolyte by the bubble effect and the gravity effect, so that the self-circulation flow of the electrolyte is realized in the electrolytic cell to equalize the temperature of the electrolyte, which can improve the stability and the service life of each component in the electrolytic cell, and is beneficial to the large-scale development of the electrolytic cell and the adaptation to the fluctuating power supply.

In addition, a catalytic layer (not shown) may be provided between the membrane 20 and the bipolar plate 10, which can improve the efficiency of hydrogen production by water electrolysis.

The present disclosure also provides a water electrolysis hydrogen production system comprising the above-described electrolyzer 100. In addition, the electrolyzed water hydrogen production system may also include two gas-liquid separators (e.g., a first gas-liquid separator 30 and a second gas-liquid separator 40, described below) for separating the gas from the liquid and for discharging a respective one of hydrogen and oxygen, respectively. In addition, the electrolyte in the electrolyzer 100 of the electrolyzed water hydrogen system may be water, acidic water, or alkaline solution, and the membrane 20 may be a proton exchange membrane, an anion exchange membrane, and a porous membrane. Three different electrolytic water hydrogen production systems will be described below with reference to fig. 6 to 8.

First electrolytic water hydrogen production system

Fig. 6 is a schematic structural diagram of a first water electrolysis hydrogen production system according to the present disclosure. In the first electrolytic water hydrogen production system, the electrolyte in the electrolytic cell 100 is water or acidic water, the membrane 20 of the electrolytic cell 100 is a proton exchange membrane, and the first side of the bipolar plate 10 is the anode side and the second side is the cathode side. The two gas-liquid separators include a first gas-liquid separator 30 and a second gas-liquid separator 40, wherein the first gas-liquid separator 30 communicates with the first discharge port 12 to receive the oxygen gas and the electrolyte discharged from the first discharge port 12 and separate the electrolyte, water, etc. from the oxygen gas, and then discharge the oxygen gas; the second gas-liquid separator 40 communicates with the second discharge port 13 to receive the hydrogen gas (including water) discharged from the second discharge port 13 and separate water in the hydrogen gas from the hydrogen gas, and then discharges the hydrogen gas. Thus, the oxygen gas discharged from the first gas-liquid separator 30 and the hydrogen gas discharged from the second gas-liquid separator 40 are dry gases containing no liquid.

In the first electrolyzed water hydrogen production system, the electrolyte is electrolyzed, oxygen is generated on the anode side and hydrogen is generated on the cathode side.

The generated oxygen gas flows in the electrolyte along the first discharge path to the first discharge port 12. At the same time, the electrolyte flows from below to above to the position of the first discharge port 12 due to the bubble effect of the oxygen. Subsequently, a part of the oxygen and the electrolyte in the first discharge port 12 flows to the first gas-liquid separator 30 through a pipe, and the remaining oxygen and electrolyte reach the lower part of the first electrolytic chamber and the liquid inlet 11 along a return path and are mixed with the electrolyte of the lower part of the first electrolytic chamber and the liquid inlet 11 to equalize the temperature of the electrolyte.

The generated hydrogen gas flows to the second discharge port 13 and then flows to the second gas-liquid separator 40 via the corresponding piping. Typically, in the first electrolytic water hydrogen production system, no electrolyte is present on the cathode side of bipolar plate 10, little electrolyte permeates through the proton exchange membrane, or little water is produced by the reaction.

Second electrolytic water hydrogen production system

Fig. 7 is a schematic structural diagram of a second water electrolysis hydrogen production system according to the present disclosure. In the second electrolytic water hydrogen production system, the electrolyte in the electrolytic tank 100 is water, the membrane 20 is an anion exchange membrane, and the first side of the bipolar plate 10 is the cathode side and the second side is the anode side. In this case, the first gas-liquid separator 30 communicates with the first discharge port 12 and discharges the dried hydrogen gas, and the second gas-liquid separator 40 communicates with the second discharge port 13 and discharges the dried oxygen gas. In addition, the roles of the first gas-liquid separator 30 and the second gas-liquid separator 40 in the second electrolyzed water hydrogen production system are opposite to those of the first gas-liquid separator 30 and the second gas-liquid separator 40 in the first electrolyzed water hydrogen production system, and thus will not be described in detail herein.

In the second electrolyzed water hydrogen production system, the electrolyte is electrolyzed to produce hydrogen on the cathode side and oxygen on the anode side.

The generated hydrogen gas flows in the electrolyte along the first discharge path to the first discharge port 12. At the same time, the electrolyte flows from bottom to top to the position of the first discharge port 12 due to the bubble effect of the hydrogen gas. Subsequently, a part of the hydrogen gas and the electrolyte in the first discharge port 12 flows to the first gas-liquid separator 30 through a pipe, and the remaining hydrogen gas and electrolyte reach the lower part of the first electrolytic chamber and the liquid inlet 11 along a return path and are mixed with the electrolyte of the lower part of the first electrolytic chamber and the liquid inlet 11 to equalize the temperature of the electrolyte.

The generated oxygen flows to the second discharge port 13 and then flows to the second gas-liquid separator 40 through the corresponding piping. Typically, in the second electrolytic water hydrogen production system, there is substantially no electrolyte on the anode side of bipolar plate 10, little electrolyte permeates through the anion exchange membrane, or little water is produced by the reaction.

Third electrolytic water hydrogen production system

Fig. 8 is a schematic structural view of a third water electrolysis hydrogen production system according to the present disclosure. In the third electrolyzed water hydrogen production system, the electrolyte in the electrolyzer 100 is an alkaline solution, the membrane 20 is a porous membrane, and the first side of the bipolar plate 10 is the cathode side and the second side is the anode side. In this case, the first gas-liquid separator 30 communicates with the first discharge port 12 and discharges the dried hydrogen gas, and the second gas-liquid separator 40 communicates with the second discharge port 13 and discharges the dried oxygen gas. Further, the second gas-liquid separator 40 communicates with the liquid inlet 11. As shown in fig. 8, the liquid discharge port of the second gas-liquid separator 40 is connected downstream of the liquid discharge port of the first gas-liquid separator 30.

The flow paths of the hydrogen and oxygen generated by the electrolysis of the electrolyte in the third water-splitting hydrogen production system may be the same as those of the hydrogen and oxygen generated by the electrolysis of the electrolyte in the second water-splitting hydrogen production system described above, and a description thereof will not be repeated here.

However, the embodiments of the present disclosure are not limited thereto, and considering that electrolyte is present at both the anode side and the cathode side of the bipolar plate 10 in the third electrolyzed water hydrogen production system, a second electrolysis chamber having a similar structure to the first electrolysis chamber may be provided at the second side of the bipolar plate 10, in which electrolyte may also be reciprocally circulated by the bubble effect, thereby achieving self-circulation flow of electrolyte in the second electrolysis chamber.

In addition, in the first and second water electrolysis hydrogen production systems, the first side of the bipolar plate 10 has the structure of the first electrolysis chamber, and the second side of the bipolar plate 10 may have the structure of the plurality of flow channels 18. In the third electrolyzed water hydrogen production system, a first side of the bipolar plate 10 has a structure of a first electrolysis chamber and a second side of the bipolar plate 10 has a structure of a second electrolysis chamber. By the structure of arranging the bipolar plates in this way, the temperature of the electrolyte in the water electrolysis hydrogen production system can be equalized. However, the embodiments according to the present disclosure are not limited thereto, and the second side of the bipolar plates of the first and second water-electrolysis hydrogen production systems may also have the structure of the second electrolysis chamber, and the second side of the bipolar plate of the third water-electrolysis hydrogen production system may also have the structure of a plurality of flow channels, as long as the temperature of the electrolyte in the electrolytic cell can be equalized.

In addition, the hydrogen generated by the water electrolysis hydrogen production system is stored in the hydrogen storage container for use after the purification process, and the generated oxygen can be directly discharged or stored in the oxygen storage container for use after the purification process.

The electrolyzed water hydrogen production system described above may also include a make-up tank 50 for replenishing the first gas-liquid separator 30 with electrolyte. In addition, the first gas-liquid separator 30 may also be in communication with the liquid inlet 11, and the first gas-liquid separator 30 is located higher than the position of the electrolytic tank 100. By thus arranging the relative positions of the first gas-liquid separator 30 and the electrolytic cell 100, electrolyte is caused to enter the electrolytic cell 100 from the first gas-liquid separator 30 by gravity and siphoning. In combination with the self-circulation flow of the electrolyte implemented in the electrolytic tank 100 described above, the self-circulation flow of the electrolyte inside the electrolytic tank and the self-circulation flow in the pipeline outside the electrolytic tank can be implemented without using a pump in the whole electrolytic water hydrogen production system, thereby reducing the energy consumption of the electrolytic water hydrogen production system and saving the hydrogen production cost. In addition, the fault risk of the electrolytic water hydrogen production system can be reduced and the maintenance cost can be reduced under the condition that a pump is not used.

Further, a part of the electrolyte and oxygen in the first discharge port 12 is refluxed to the lower part of the first electrolytic chamber and the liquid inlet 11, and the remaining part is discharged through the first discharge port 12 into the first gas-liquid separator 30 outside the electrolytic tank 100, participating in the self-circulation flow in the piping outside the electrolytic tank.

As shown in fig. 6 and 7, in the first and second electrolyzed water hydrogen production systems, water generated after separating gas by the second gas-liquid separator 40 may be discharged into the water tank 80. In this case, the position of the first gas-liquid separator 30 is set to be higher than the position of the electrolytic tank 100, so that self-circulation of the electrolyte outside the electrolytic tank 100 can be achieved in a line connecting the first gas discharge port of the electrolytic tank 100, the first gas-liquid separator 30, and the electrolyte inlet port of the electrolytic tank 100 in this order (i.e., a line located on the left side of the electrolytic tank 100 in fig. 6 and 7). Further, water in the water tank 80 may be supplied to the fluid replacement tank 50.

In addition, as shown in fig. 8, the liquid replenishing tank 50 communicates with the first gas-liquid separator 30 and the second gas-liquid separator 40 is connected to a pipe between the first gas-liquid separator 30 and the liquid inlet 11. In this case, the positions of the first gas-liquid separator 30 and the second gas-liquid separator 40 are set to be higher than the position of the electrolytic cell 100, so that self-circulation of the electrolyte outside the electrolytic cell 100 can be achieved in the piping connecting the first gas discharge port of the electrolytic cell 100, the first gas-liquid separator 30, and the electrolyte inlet port of the electrolytic cell 100, and the piping connecting the second gas discharge port of the electrolytic cell 100, the liquid discharge port of the second gas-liquid separator 40, and the electrolyte inlet port of the electrolytic cell 100. However, the present disclosure is not limited thereto, and only one of the first gas-liquid separator 30 and the second gas-liquid separator 40 may be disposed at a position higher than the electrolytic tank 100.

In addition, the electrolyzed water hydrogen system described above may also include an ion exchange column 60 and/or a heat exchanger 70 positioned between the first gas-liquid separator 30 and the liquid inlet 11. The ion exchange column 60 is capable of removing ionic impurities from the electrolyte (e.g., due to metal ions generated during electrolysis, etc.) so as to avoid such ionic impurities from affecting the useful life of the membrane or bipolar plate. Heat exchanger 70 is capable of reducing the temperature of the electrolyte entering inlet 11, thereby reducing the temperature of the electrolyte entering the electrolyzed water hydrogen production system. However, the present disclosure is not limited thereto, and the electrolyzed water hydrogen production system may not include an ion exchange column, for example, as shown in fig. 8, and the third electrolyzed water hydrogen production system may not include an ion exchange column. In addition, the heat exchanger 70 may be selectively provided as needed.

By employing the bipolar plate according to the present disclosure, it is possible to self-circulate the electrolyte in the first electrolytic chamber and equalize the temperature of the electrolyte in the first electrolytic chamber (e.g., to bring the temperature difference of the electrolyte between the liquid inlet and the first outlet within an acceptable range). In addition, by applying the bipolar plate according to the present disclosure to an electrolytic cell, self-circulation flow of an electrolyte is achieved in the electrolytic cell to equalize the temperature of the electrolyte, which can improve stability and service life of individual components in the electrolytic cell while facilitating large-scale development of the electrolytic cell and adaptation to a fluctuating power supply.

Although a few embodiments of the present disclosure have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined in the claims and their equivalents.

Claims (14)

1. A bipolar plate for use in a water electrolysis hydrogen production system and having a first side and a second side opposite to each other, characterized in that a first electrolysis chamber is formed at the first side of the bipolar plate (10), a liquid inlet (11) communicating with the first electrolysis chamber is formed at the lower part of the bipolar plate (10), a first discharge outlet (12) communicating with the first electrolysis chamber and a second discharge outlet (13) communicating with the second side of the bipolar plate (10) are formed at the upper part of the bipolar plate (10),

wherein a liquid outlet (14) and a reflux port (15) which enable the first discharge port (12) to be communicated with the first electrolysis chamber are formed on the top wall of the first electrolysis chamber, the liquid outlet (14) and the reflux port (15) are adjacently arranged and are mutually separated,

wherein a partition plate (16) is provided in an upper portion of the first electrolytic chamber, the partition plate (16) partitions the upper portion of the first electrolytic chamber into a first chamber and a second chamber such that the first chamber is opposed to and communicates with the liquid outlet (14), the second chamber is opposed to and communicates with the return port (15), and a lower portion of the first chamber and a lower portion of the second chamber communicate with each other.

2. The bipolar plate according to claim 1, characterized in that the liquid outlet openings (14) are provided in a plurality and spaced apart from each other on the top wall of the first electrolysis chamber.

3. Bipolar plate according to claim 1, characterized in that the separator plate (16) is inclined with respect to or parallel to the surface of the first side.

4. A bipolar plate according to claim 3, characterised in that the distance between the separator plate (16) and the surface of the first side decreases gradually from top to bottom.

5. A bipolar plate according to claim 1, characterized in that a plurality of diverting protrusions (17) are provided on the portion of the surface of the first side near the inlet opening (11).

6. A bipolar plate according to any one of claims 1 to 5, characterized in that a plurality of flow channels (18) are formed on the surface of the second side of the bipolar plate (10), the plurality of flow channels (18) being in communication with the second discharge opening (13).

7. Bipolar plate according to any of claims 1 to 5, wherein a second electrolysis chamber is formed at a second side of the bipolar plate (10), which second electrolysis chamber communicates with the second discharge opening (13) and the liquid inlet opening (11).

8. An electrolytic cell, characterized in that the electrolytic cell (100) comprises:

at least two bipolar plates (10) according to any of claims 1 to 7, arranged in a stack with the first sides of the bipolar plates (10) facing in the same direction;

a separator (20) disposed between adjacent two bipolar plates (10) of the at least two bipolar plates (10);

a seal disposed between the bipolar plate (10) and the separator (20).

9. An electrolytic cell according to claim 8, characterised in that a catalytic layer is provided between the membrane (20) and the bipolar plate (10).

10. A water electrolysis hydrogen production system, comprising:

the electrolyzer (100) of claim 8 or 9, the membrane (20) being a proton exchange membrane, the first side being the anode side and the second side being the cathode side;

a first gas-liquid separator (30) in communication with the first discharge port (12) and for discharging oxygen;

and a second gas-liquid separator (40) which communicates with the second discharge port (13) and discharges hydrogen.

11. A water electrolysis hydrogen production system, comprising:

the electrolytic cell (100) of claim 8 or 9, the membrane (20) being an anion exchange membrane, the first side being a cathode side and the second side being an anode side;

a first gas-liquid separator (30) communicating with the first discharge port (12) and for discharging hydrogen gas;

and a second gas-liquid separator (40) which communicates with the second discharge port (13) and discharges oxygen.

12. A water electrolysis hydrogen production system, comprising:

the electrolytic cell (100) of claim 8 or 9 wherein the membrane (20) is a porous membrane, the first side being the cathode side and the second side being the anode side;

a first gas-liquid separator (30) communicating with the first discharge port (12) and for discharging hydrogen gas;

and a second gas-liquid separator (40) which is communicated with the second discharge port (13) and the liquid inlet (11) and is used for discharging oxygen.

13. The electrolytic water hydrogen production system according to any one of claims 10 to 12, further comprising a make-up tank (50) for replenishing the first gas-liquid separator (30) with electrolyte, wherein the first gas-liquid separator (30) is further in communication with the liquid inlet (11) and the first gas-liquid separator (30) is located higher than the position of the electrolyzer (100).

14. The electrolyzed water hydrogen system of claim 13 further comprising an ion exchange column (60) and/or a heat exchanger (70) positioned between the first gas-liquid separator (30) and the liquid inlet (11).