Intercepting type flow field assembly and alkaline water electrolytic bath with same

Abstract

The invention relates to the technical field of electrolytic hydrogen production equipment, and discloses a cut-off type flow field assembly and an alkaline water electrolytic bath with the cut-off type flow field assembly. The cut-off type flow field assembly comprises a polar plate, a concave cavity is formed in the plate face of one side of the polar plate, and a plurality of liquid inlets are formed in the bottom of the polar plate and used for electrolyte to flow into the concave cavity; the top of the polar plate is provided with a liquid outlet for the electrolyte to flow out of the concave cavity; an intercepting belt is arranged in the concave cavity, is transversely arranged between the plurality of liquid inlets and the liquid outlet, and can partially block the electrolyte flowing towards the direction of the liquid outlet; the intercepting type flow field assembly provided by the invention can effectively improve the phenomenon of uneven distribution of the electrolyte, thereby effectively reducing the adverse effect caused by the uneven distribution of the electrolyte.

Description

Technical Field

[0001] The present invention relates to the technical field of electrolytic hydrogen production equipment, and in particular to a cut-off flow field component and an alkaline water electrolyzer having the same. Background Art

[0002] Among the technologies involved in hydrogen production through water electrolysis, alkaline water electrolysis has gained widespread application due to its mature technology, low cost, and suitability for large-scale commercial production. The basic principle of alkaline water electrolysis is to pass direct current between the cathode and anode of an electrolyzer, causing water molecules in the electrolyte to undergo an electrochemical reaction at the electrodes to produce hydrogen and oxygen. To ensure the reaction continues, the electrolyzer is equipped with a liquid inlet and outlet to allow the electrolyte to flow continuously through the cell.

[0003] In the prior art, with the continuous development of high-power water electrolysis technology, the size of the electrolytic cell is gradually increasing, and the adverse effects of uneven distribution of the electrolyte in the electrolytic cell are becoming more and more prominent. Specifically, uneven electrolyte distribution will directly lead to uneven current density distribution during the electrolysis process. Some areas may have too high or too low current density, thereby reducing the efficiency of the electrolysis reaction, and excessive current density in local areas will cause local corrosion or thermal damage to the electrodes and the inner wall of the electrolytic cell, affecting the service life of the electrolytic cell and increasing maintenance costs; in addition, the uneven distribution of the electrolyte will cause changes in local resistance, resulting in increased resistance in some areas, requiring higher voltage to maintain the required electrolysis reaction, thereby increasing energy consumption; in addition, the uneven distribution of the electrolyte will also cause fluctuations in the quality of hydrogen or oxygen, affecting the purity and stability of the final product. It can be seen that in order to maximize the efficiency and economy of alkaline water electrolysis technology, it is crucial to ensure the uniform distribution of the electrolyte throughout the electrolytic cell. Summary of the Invention

[0004] The purpose of the present invention is to solve the problem of uneven distribution of electrolyte in the electrolytic cell and to provide a cut-off flow field component and an alkaline water electrolytic cell having the same. The cut-off flow field component can effectively improve the uneven distribution of electrolyte in the electrolytic cell.

[0005] In order to achieve the above-mentioned objectives, the present invention provides a cut-off flow field assembly, comprising an electrode plate, a concave cavity being provided on one side surface of the electrode plate, a plurality of liquid inlets being provided at the bottom of the electrode plate for electrolyte to flow into the concave cavity, and a liquid outlet being provided at the top of the electrode plate for electrolyte to flow out of the concave cavity; an intercepting belt being provided in the concave cavity, the intercepting belt being horizontally arranged between the plurality of liquid inlets and the liquid outlet and being capable of partially blocking the electrolyte flowing in the direction toward the liquid outlet.

[0006] Preferably, the intercepting strip is linear and extends in a horizontal direction.

[0007] Preferably, the intercepting band is in an elliptical arc shape, and the arc surface of the intercepting band is arranged to be convex toward the direction where the multiple liquid inlets are located.

[0008] Preferably, the height of the intercepting zone is lower than the depth of the cavity.

[0009] Preferably, a plurality of intercepting belts are provided, and the plurality of intercepting belts are sequentially and spaced apart from each other between the liquid inlet and the liquid outlet.

[0010] Preferably, the cavity is disc-shaped, and pairs of the multiple liquid inlets are symmetrically arranged about a perpendicular midline passing through the center of the cavity and extending in the vertical direction.

[0011] Preferably, a plurality of liquid outlets are provided, and the plurality of liquid outlets are sequentially and spaced apart from each other on the top of the electrode plate.

[0012] Preferably, a plurality of liquid inlet guiding devices are provided at the bottom of the electrode plate, and the plurality of liquid inlet guiding devices correspond one-to-one to the plurality of liquid inlets so as to guide the electrolyte flowing into the concave cavity from each of the liquid inlets upward.

[0013] Preferably, the liquid inlet guiding device comprises two parallel and spaced-apart guiding plates, and the liquid inlet is arranged between the two guiding plates so that the flow direction of the electrolyte can be restricted by the two guiding plates.

[0014] The present invention also provides an alkaline water electrolyzer, which has the above-mentioned intercepting flow field component.

[0015] In the technical solution provided by the present invention, a cut-off belt is provided in the concave cavity of the electrode plate, and the cut-off belt is placed horizontally between multiple liquid inlets and liquid outlets and can partially block the electrolyte flowing in the direction toward the liquid outlet. When the electrolyte flows into the concave cavity through multiple liquid inlets and is partially blocked by the cut-off belt, the electrolyte can gradually fill the area between the cut-off belt and the multiple liquid inlets, and then flow upward as a whole and flow out of the concave cavity through the liquid outlet. Therefore, the setting of the cut-off belt can effectively improve the uneven distribution of the electrolyte, thereby effectively reducing the adverse effects caused thereby. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic structural diagram of a shut-off flow field assembly provided by the present invention;

[0017] Figure 2 It is a structural schematic diagram of another intercepting flow field assembly provided by the present invention;

[0018] Figure 3 Schematic diagram of a verification system for simulating the flow state of an electrolyte in a shut-off flow field assembly provided by the present invention;

[0019] Figure 4 This is a photograph of the intercepting flow field assembly provided in Example 1 after 150 seconds according to the liquid inlet method 1;

[0020] Figure 5 This is a photograph of the flow state of the intercepting flow field component provided in Example 1 after 150 seconds according to the liquid inlet conditions of Test Examples 1-4.

[0021] Description of Reference Numerals

[0022] 1. Pure water storage tank; 2. Fluorescent dye storage tank; 3. Pump; 4. Controller; 5. Camera; 6. Ultraviolet lamp; 10. Plate; 101. Liquid inlet; 102. Liquid outlet; 11. Concave cavity; 20. Intercepting zone; 21. First intercepting zone; 22. Second intercepting zone; 23. Third intercepting zone; 24. Fourth intercepting zone; 30. Liquid inlet guide device; 31. Guide plate. DETAILED DESCRIPTION

[0023] The following describes the specific embodiments of the present invention in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0024] As mentioned above, combined with Figure 1 As shown, the present invention provides a cut-off flow field assembly, comprising a plate 10, a concave cavity 11 being provided on one side surface of the plate 10, a plurality of liquid inlets 101 being provided at the bottom of the plate 10 for electrolyte to flow into the concave cavity 11, and a liquid outlet 102 being provided at the top of the plate 10 for electrolyte to flow out of the concave cavity 11; a cut-off belt 20 being provided in the concave cavity 11, the cut-off belt 20 being horizontally arranged between the plurality of liquid inlets 101 and the liquid outlet 102 and being capable of partially blocking the electrolyte flowing in the direction toward the liquid outlet 102.

[0025] The inventors of the present application accidentally discovered that by arranging a cut-off strip 20 in the concave cavity 11 of the electrode 10, the cut-off strip 20 is placed horizontally between the multiple liquid inlets 101 and the liquid outlet 102 and can partially block the electrolyte flowing in the direction toward the liquid outlet 102. When the electrolyte flows into the concave cavity 11 through the multiple liquid inlets 101 and is partially blocked by the cut-off strip 20, the electrolyte can gradually fill the area between the cut-off strip 20 and the multiple liquid inlets 101, and then flow upward as a whole and flow out of the concave cavity 11 through the liquid outlet 102. Therefore, the arrangement of the cut-off strip 20 can effectively improve the uneven distribution of the electrolyte, thereby effectively reducing the adverse effects caused thereby.

[0026] In the present invention, the electrolyte may be one commonly used by those skilled in the art, for example, a 30% KOH solution or a 25% NaOH solution commonly used by those skilled in the art.

[0027] It can be understood that in the present invention, by providing multiple liquid inlets 101, the uniformity of the distribution of the electrolyte in the concave cavity 11 can be improved to a certain extent. For example, in a specific embodiment of the present invention, there are eight liquid inlets 101, and the central angle of the concave cavity 11 corresponding to two adjacent liquid inlets 101 is 15°.

[0028] In the present invention, the intercepting belt 20 can be placed horizontally between the plurality of liquid inlets 101 and the liquid outlets 102 in any appropriate manner, such as Figure 1 As shown, in some embodiments, the intercepting strip 20 is linear and extends horizontally. As the electrolyte flows through the intercepting strip 20, part of the electrolyte is blocked and guided by the intercepting strip 20 along both ends in the horizontal direction, thereby achieving uniform distribution throughout the cavity 11.

[0029] like Figure 2 As shown, in some embodiments, the intercepting band 20 is in an elliptical arc shape, and the arc surface of the intercepting band 20 is set to be convex toward the direction of the multiple liquid inlets 101. Through this structural setting, the elliptical arc-shaped intercepting band 20 can guide the remaining electrolyte in the direction toward the two ends and toward the liquid outlet 102 during the process of partially blocking the electrolyte. This not only improves the uniformity of the distribution of the electrolyte in the concave cavity 11, but also reduces the pressure of the electrode 10 in this area, thereby ensuring the stable operation of the equipment.

[0030] In the present invention, the intercepting strip 20 may adopt any appropriate structural form to partially block the electrolyte flowing toward the liquid outlet 102. For example, a through hole may be provided on the intercepting strip 20, so that part of the electrolyte flows through the intercepting strip 20 through the through hole, while the remaining electrolyte is blocked by the intercepting strip 20. In some embodiments, the height of the intercepting strip 20 is lower than the depth of the cavity 11. For example, in a specific embodiment of the present invention, the depth of the cavity 11 is 5 mm, and the height of the intercepting strip 20 is 4 mm, that is, there is a gap of 1 mm to allow the electrolyte to flow toward the liquid outlet 102.

[0031] In the present invention, in order to improve the blocking effect of the intercepting belt 20 on the electrolyte, ensure that the electrolyte can quickly fill the area between the intercepting belt 20 and the multiple liquid inlets 101, and then advance as a whole in the direction toward the liquid outlet 102, the intercepting belt 20 is provided in plurality, and the plurality of intercepting belts 20 are arranged in sequence and at intervals between the liquid inlet 101 and the liquid outlet 102.

[0032] In some embodiments, the cavity 11 is disc-shaped, and two of the plurality of liquid inlets 101 are symmetrically arranged about a perpendicular bisector passing through the center of the cavity 11 and extending in the vertical direction. This structural arrangement improves the uniformity of electrolyte inflow into the cavity 11.

[0033] In some embodiments, the liquid outlet 102 is provided in plurality, and the plurality of liquid outlets 102 are sequentially and spaced apart from each other on the top of the electrode plate 10. It is understood that the plurality of liquid outlets 102 can enable the electrolyte that has completed the electrolysis reaction to flow out of the cavity 11 more quickly. Exemplarily, the liquid outlet 102 is provided in four, and the four liquid outlets 102 are sequentially and spaced apart from each other on the top of the electrode plate 10.

[0034] In some embodiments, a plurality of liquid inlet guiding devices 30 are provided at the bottom of the electrode plate 10 , and the plurality of liquid inlet guiding devices 30 correspond one-to-one to the plurality of liquid inlets 101 to guide the electrolyte flowing into the cavity 11 from each liquid inlet 101 upward.

[0035] In the present invention, the liquid inlet guiding device 30 may adopt any appropriate structural form, as long as it can guide the flow direction of the electrolyte flowing into the concave cavity 11 from the liquid inlet 101. In some embodiments, the liquid inlet guiding device 30 includes two parallel and spaced guide plates 31, and the liquid inlet 101 is disposed between the two guide plates 31 so that the flow direction of the electrolyte can be restricted by the two guide plates 31.

[0036] The intercepting flow field assembly provided by the present invention is further described below through specific embodiments.

[0037] Example 1

[0038] Combine Figure 1 As shown, the intercepting flow field assembly provided in this embodiment includes an electrode plate 10, and a concave cavity 11 with a depth of 5 mm is provided on one side surface of the electrode plate 10. The concave cavity 11 is disc-shaped and has a diameter of 1940 mm; eight liquid inlets 101 are provided at the bottom of the electrode plate 10 for the electrolyte to flow into the concave cavity 11. For the convenience of subsequent description, the eight liquid inlets 101 are numbered 1#, 2#, 3#, ..., 7#, 8# from left to right; the diameter of each liquid inlet 101 is 10 mm, and the distance from the center of the concave cavity 11 is 900 mm. The central angle of the corresponding concave cavity 11 between two adjacent liquid inlets 101 is 15°, and two of the eight liquid inlets 101 are symmetrically arranged about the perpendicular bisector passing through the center of the concave cavity 11 and extending in the vertical direction.

[0039] A liquid inlet guiding device 30 is provided at each liquid inlet 101 , and the liquid inlet guiding device 30 is used to guide the electrolyte flowing into the concave cavity 11 through the corresponding liquid inlet 101 upward.

[0040] Four liquid outlets 102 are provided on the top of the electrode plate 10 to allow the electrolyte to flow out of the cavity 11 .

[0041] Four horizontally extending intercepting strips 20 are provided within the cavity 11. Each of these intercepting strips 20 is 10 mm wide and 4 mm high. From bottom to top, the four intercepting strips 20 are: a first intercepting strip 21, a second intercepting strip 22, a third intercepting strip 23, and a fourth intercepting strip 24. The first intercepting strip 21 is flush with the 2# and 7# liquid inlets 101 at its ends; the second intercepting strip 22 is flush with the 1# and 8# liquid inlets 101 at its ends. The first intercepting strip 21 is 1013 mm long, the second intercepting strip 22 is 1347 mm long, the third intercepting strip 23 is 1738 mm long, and the fourth intercepting strip 24 is 1845 mm long.

[0042] In order to verify the improvement effect of the intercepting flow field assembly provided by the present invention on the flow state of the electrolyte. The present invention also provides a verification system for simulating the flow state of the electrolyte in the intercepting flow field assembly, such as Figure 3 As shown, the verification system includes a pure water storage tank 1, a fluorescent dye storage tank 2, a pump 3, a controller 4, a camera 5, and an ultraviolet lamp 6; wherein the controller 4 can control the pump 3 to pump the pure water in the pure water storage tank 1 and the fluorescent dye in the fluorescent dye storage tank 2 independently at a certain flow rate and flow rate into the intercepting flow field component of the present invention, and the liquid flows into the concave cavity 11 from the eight liquid inlets 101 at the bottom of the electrode plate 10, flows through the concave cavity 11 vertically from bottom to top, and flows out of the concave cavity 11 from the four liquid outlets 102 at the top of the electrode plate 10.

[0043] During actual verification, pure water is first introduced to fill the cavity 11. After reaching a stable flow, fluorescent dye is introduced at the same flow rate. The ultraviolet lamp 6 is turned on under dark conditions, and photos are taken through the camera 5 to observe and record the flow distribution of the fluorescent dye in the cavity 11, thereby simulating the flow state of the electrolyte in the interception type flow field component.

[0044] Furthermore, in order to fully consider the influence of flow rate on the flow state of the electrolyte in the cavity 11, the present invention also provides two liquid inlet methods, specifically:

[0045] Liquid Inlet Method 1: The flow rate of each liquid inlet remains unchanged, and the total liquid inlet volume is adjusted. The specific liquid inlet conditions of this liquid inlet method are shown in Table 1 below, where the unit of the liquid inlet flow rate of a single liquid inlet is L / min.

[0046] Table 1:

[0047]

[0048]

[0049] like Figure 4 The photo shows the intercepting flow field assembly provided in Example 1 after 150 seconds in liquid inlet mode 1. As can be seen from the photo, the intercepting flow field assembly provided by the present invention can achieve uniform dispersion of the fluorescent dye throughout the entire cavity.

[0050] Liquid inlet method 2: The total liquid inlet volume remains unchanged at 360L / h, and the flow rate of each liquid inlet is adjusted.

[0051] As shown in Table 2 below, this liquid inlet method includes four test cases, namely Test Cases 1, 2, 3, and 4. The unit of the liquid inlet flow rate for a single liquid inlet is L / min. For example, in Test Case 1, the liquid inlet flow rates for inlets 1#-8# were 0.3 L / min, 0.6 L / min, 0.9 L / min, 1.2 L / min, 1.2 L / min, 0.9 L / min, 0.6 L / min, and 0.3 L / min, respectively. Liquid was introduced into the intercepting flow field assembly provided in Example 1 according to these inlet conditions, and the flow state of the fluorescent dye was observed and recorded.

[0052] Table 2:

[0053]

[0054] like Figure 5 Photographs of the flow state of the intercepting flow field assembly provided in Example 1 after 150 seconds, following the liquid inlet conditions of Experiments 1-4. The photographs show that, with this inlet method, all three experiments, except Experiment 1, exhibited a certain degree of flow unevenness. The inventors speculate that, with this inlet method, a total inlet volume of 360 L / h represents a high flow rate. Therefore, only by concentrating the high-flow inlet at the center of the electrode plate, as in Experiment 1, could uniform liquid distribution within the cavity be ensured.

[0055] The second aspect of the present invention provides an alkaline water electrolyzer, which has the above-mentioned intercepting flow field assembly. In the present invention, through the alkaline water electrolyzer with the above-mentioned intercepting flow field assembly, the electrolyte flowing into the concave cavity 11 through the liquid inlet 101 can be partially blocked by the intercepting belt 20 placed horizontally between the multiple liquid inlets 101 and the liquid outlet 102. After the electrolyte fills the area between the intercepting belt 20 and the multiple liquid inlets 101, it flows upward as a whole and flows out of the concave cavity 11 through the liquid outlet 102. Therefore, based on the intercepting flow field assembly provided by the present invention, the uneven distribution of the electrolyte in the concave cavity 11 is effectively improved, thereby reducing the adverse effects caused thereby, so that the alkaline water electrolyzer has better stability and higher electrolytic hydrogen production efficiency.

[0056] While the preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, the present invention is not limited thereto. Within the technical scope of the present invention, various simple variations of the technical solution of the present invention may be made. To avoid unnecessary repetition, the present invention will not further describe various possible combinations. However, these simple variations and combinations should also be considered as disclosed herein and fall within the scope of protection of the present invention.

Claims

1. A shut-off flow field assembly, characterized in that: The invention comprises an electrode plate (10), wherein a concave cavity (11) is provided on one side surface of the electrode plate (10), a plurality of liquid inlets (101) are provided at the bottom of the electrode plate (10) for electrolyte to flow into the concave cavity (11), and a liquid outlet (102) is provided at the top of the electrode plate (10) for electrolyte to flow out of the concave cavity (11); a cut-off strip (20) is provided in the concave cavity (11), and the cut-off strip (20) is horizontally arranged between the plurality of liquid inlets (101) and the liquid outlet (102) and is capable of partially blocking the electrolyte flowing in the direction toward the liquid outlet (102).

2. The intercepting flow field assembly according to claim 1, characterized in that: The intercepting strip (20) is linear and extends in a horizontal direction.

3. The intercepting flow field assembly according to claim 1, characterized in that: The intercepting belt (20) is in the shape of an elliptical arc, and the arc surface of the intercepting belt (20) is arranged to be convex toward the direction where the multiple liquid inlets (101) are located.

4. The shut-off flow field assembly according to claim 1, characterized in that: The height of the intercepting zone (20) is lower than the depth of the concave cavity (11).

5. The intercepting flow field assembly according to claim 1, characterized in that: A plurality of intercepting belts (20) are provided, and the plurality of intercepting belts (20) are sequentially and spaced apart between the liquid inlet (101) and the liquid outlet (102).

6. The intercepting flow field assembly according to claim 1, characterized in that: The concave cavity (11) is disc-shaped, and two of the multiple liquid inlets (101) are symmetrically arranged about a perpendicular midline passing through the center of the concave cavity (11) and extending in the vertical direction.

7. The intercepting flow field assembly according to claim 1, characterized in that: A plurality of liquid outlets (102) are provided, and the plurality of liquid outlets (102) are sequentially and spaced apart from each other on the top of the electrode plate (10).

8. The intercepting flow field assembly according to any one of claims 1 to 7, characterized in that: A plurality of liquid inlet guiding devices (30) are provided at the bottom of the electrode plate (10), and the plurality of liquid inlet guiding devices (30) correspond one-to-one to the plurality of liquid inlets (101) so as to guide the electrolyte flowing into the concave cavity (11) from each of the liquid inlets (101) upward.

9. The intercepting flow field assembly according to claim 8, characterized in that: The liquid inlet guiding device (30) comprises two parallel and spaced guide plates (31), and the liquid inlet (101) is arranged between the two guide plates (31) so that the flow direction of the electrolyte can be restricted by the two guide plates (31).

10. An alkaline water electrolyzer, characterized in that: The alkaline water electrolyzer comprises the intercepting flow field assembly according to any one of claims 1 to 9.

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