A multi-channel liquid inlet and exhaust structure for a large alkaline water electrolysis cell

Abstract

The application relates to a multi-channel liquid inlet and exhaust structure for a large-scale alkaline electrolytic cell, the electrolytic cell comprising a cell body, a front polar plate, a rear polar plate, a front end pressing plate and a rear end pressing plate, the cell body, the front polar plate and the rear polar plate are all provided with inner cavities, the front polar plate and the rear polar plate are provided with radial holes, and a plurality of electrolytic small chambers are arranged in the inner cavities of the cell body; a plurality of electrolyte inlets are arranged on the right side of the front end pressing plate, a plurality of electrolyte inlets are arranged on the left side of the front end pressing plate, the electrolyte inlets are communicated with the inner cavities of the rear polar plate, hydrogen outlets and oxygen outlets are arranged on the upper end of the front end pressing plate, and the hydrogen outlets and the oxygen outlets are communicated with the inner cavities of the rear polar plate. Compared with the prior art, for the large-scale alkaline electrolytic cell, a plurality of electrolyte inlets are additionally arranged, the structure of the multi-channel alkaline electrolytic cell is designed, the electrolyte circulation in the electrolytic cell is increased, the internal heat exchange of the electrolytic cell is increased, the uniform distribution of the flow field and the uniform distribution of the temperature are ensured, thereby energy is saved and the normal work of the electrolytic cell is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrogen production by electrolysis of water, in particular to a multi-channel liquid inlet and exhaust structure for a large-scale alkaline water electrolysis cell. BACKGROUND

[0002] As a green hydrogen production method, the scale of hydrogen production by electrolysis of water using renewable energy is gradually increasing with the rapid development of hydrogen energy. As a key equipment for hydrogen production by electrolysis of water using renewable energy, the alkaline electrolysis cell gradually develops towards large-scale with the increase of the scale of hydrogen production by renewable energy.

[0003] Industrial alkaline electrolysis cells are generally stacked by multiple electrolysis chambers, and an alkali inlet is provided for the required alkali. This liquid supply structure is suitable for small and medium-sized electrolysis cells, but as the alkaline water electrolysis cell becomes larger, the end face diameter of the alkaline electrolysis cell increases, which inevitably greatly increases the number of electrolysis chambers. Although a single alkali inlet can provide the amount of alkali required for hydrogen production, it cannot ensure uniform heat and mass transfer distribution of the alkali in circulation. The increase in the number of electrolysis chambers causes the uniformity of the flow field in the electrolysis cell to deteriorate, the temperature difference of each electrolysis chamber increases, the flow resistance of the electrolyte increases, and the operating state of the electrolysis cell deteriorates. Therefore, as the volume of the cell increases, the internal temperature and mass transfer of the electrolysis cell become more uneven.

[0004] The uneven internal temperature distribution of the electrolysis cell not only shortens the service life of the electrolysis cell, but also greatly wastes the input electric energy. Chinese patent CN212669809U discloses a novel flow channel flow field structure water electrolysis cell, which separates the cell body by setting an intermediate polar plate, and forms two independent circulations for the front half cell and the rear half cell without interference. The essence is to divide the large-scale alkaline water electrolysis cell into two small and medium-sized electrolysis cells, and the liquid inlet and exhaust channel is not substantially improved. Therefore, in order to save energy and ensure the normal operation of the electrolysis cell, a new type of flow channel flow field structure needs to be designed. SUMMARY

[0005] The purpose of the present application is to overcome the defects of the prior art and provide a multi-channel liquid inlet and exhaust structure for a large-scale alkaline water electrolysis cell.

[0006] The purpose of the present application can be achieved by the following technical solutions:

[0007] A multi-channel liquid inlet and exhaust structure for a large-scale alkaline water electrolysis cell, the electrolysis cell comprising a cell body, a front polar plate and a rear polar plate arranged at both ends of the cell body, and a front end plate and a rear end plate arranged at both ends of the cell body, the cell body, the front polar plate and the rear polar plate are all provided with an inner cavity, the front polar plate and the rear polar plate are provided with radial holes, and the inner cavity of the cell body is provided with multiple electrolysis chambers;

[0008] The right side of the front pressing plate is provided with a plurality of electrolyte inlets, the left side of the front pressing plate is provided with a plurality of electrolyte inlets, the electrolyte inlets are communicated with the inner cavity of the rear polar plate, the upper end of the front pressing plate is provided with a hydrogen outlet and an oxygen outlet, and the hydrogen outlet and the oxygen outlet are communicated with the inner cavity of the rear polar plate.

[0009] Preferably, the electrolyte inlets are communicated with the inner cavity of the rear polar plate through electrolyte channels, and the electrolyte channels are communicated with the hydrogen production chamber of the cathode and the oxygen production chamber of the anode of each electrolysis cell.

[0010] Preferably, the hydrogen outlet is communicated with the inner cavity of the rear polar plate through a hydrogen channel, the oxygen outlet is communicated with the inner cavity of the rear polar plate through an oxygen channel, and the hydrogen and oxygen generated by the electrolysis cell are transported to the hydrogen outlet and the oxygen outlet through the hydrogen channel and the oxygen channel for discharge.

[0011] Preferably, the right side of the front pressing plate is provided with 2-10 electrolyte inlets.

[0012] Preferably, the right side of the front pressing plate is provided with 3-6 electrolyte inlets.

[0013] Preferably, the left side of the front pressing plate is provided with 2-10 electrolyte inlets.

[0014] Preferably, the left side of the front pressing plate is provided with 3-6 electrolyte inlets.

[0015] Preferably, the electrolyte inlets on the right side of the front pressing plate are uniformly distributed on the right side of the front pressing plate.

[0016] Preferably, the electrolyte inlets on the left side of the front pressing plate are uniformly distributed on the left side of the front pressing plate.

[0017] Preferably, each electrolyte inlet is provided with a flow rate adjusting device.

[0018] Compared with the prior art, the present application has the following beneficial effects:

[0019] (1) For large-scale alkaline electrolytic cells, a plurality of electrolyte inlets and electrolyte channels are added, and the structure of the multi-channel alkaline electrolytic cell is designed, the electrolyte circulation in the electrolytic cell is increased, the internal heat exchange of the electrolytic cell is increased, the flow field distribution is uniform, the temperature distribution is uniform, thereby saving energy and ensuring the normal work of the electrolytic cell.

[0020] (2) For large-scale alkaline electrolytic cells, the provision of a plurality of electrolyte inlets provides the feasibility of electrolyte circulation strategies under different working conditions, and the possibility of using different electrolyte circulation strategies under different working conditions is increased by changing the electrolyte flow of different electrolyte inlets to realize internal circulation heat exchange strategies.

[0021] (3) Small and medium-sized electrolytic cell is generally designed as a structure of one electrolyte inlet and one electrolyte channel, all electrolytic cells in the cell are supplied with electrolyte from one electrolyte inlet, when the size of the electrolytic cell is increased, the flow field distribution in the single electrolytic cell is uneven, and a backflow area is generated at the inlet of the lower end of the electrolytic cell, the application adds a multi-channel electrolyte circulation structure, which can effectively improve the uneven flow field distribution.

[0022] (4) The added multiple electrolyte inlets are arranged on the left and right sides of the front end plate, and the heat exchange of the electrolyte on the two sides can be increased during the electrolyte circulation, so that the temperature distribution of the electrolyte on the two sides of the end plate along the depth direction of the cell body is uniform. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The structure of the application is shown in the figure;

[0024] The figure shows that: 1, cell body, 2, front plate, 3, rear plate, 4, front end plate, 5, electrolyte inlet on the right side of the front end plate, 6, electrolyte inlet on the left side of the front end plate, 7, hydrogen outlet, 8, oxygen outlet, 9, electrolyte channel of the electrolyte inlet on the right side of the front end plate, 10, electrolyte channel of the electrolyte inlet on the left side of the front end plate, 11, hydrogen channel, 12, oxygen channel. DETAILED DESCRIPTION

[0025] The application will be described in detail below in combination with the drawings and specific examples. The present embodiment is implemented on the basis of the technical scheme of the application, and detailed implementation and specific operation process are given, but the protection scope of the application is not limited to the following examples.

[0026] In the drawings, components with the same structure are indicated by the same reference numerals, and components with similar structure or function are indicated by similar reference numerals. The size and thickness of each component shown in the drawings are arbitrarily shown, and the application does not limit the size and thickness of each component. In order to make the drawing clearer, the components are appropriately exaggerated in some places in the drawing.

[0027] Example 1:

[0028] For alkaline electrolytic cell, hydrogen is produced by alkaline electrolysis, in order to improve the mass transfer in the cell and make the temperature distribution of the electrolytic cell tend to be uniform, the application provides a new multi-channel electrolytic cell flow field structure:

[0029] A multi-channel liquid inlet and gas exhaust structure for large-scale alkaline water electrolytic cell, the electrolytic cell comprises a cell body 1, front plates 2 and rear plates 3 arranged at both ends of the cell body 1, front end plates 4 and rear end plates arranged at both ends of the cell body 1, the cell body 1, the front plates 2 and the rear plates 3 are all provided with inner cavities, the front plates 2 and the rear plates 3 are provided with radial holes, and the inner cavities of the cell body 1 are provided with multiple electrolytic cells;

[0030] The right side of the front pressing plate 4 is provided with a plurality of electrolyte inlets (i.e. Figure 1 middle electrolyte inlets 5), and the left side of the front pressing plate 4 is provided with a plurality of electrolyte inlets (i.e. Figure 1 middle electrolyte inlets 6). The electrolyte inlets are communicated with the inner cavity of the rear electrode plate 3. The upper end of the front pressing plate 4 is provided with a hydrogen outlet 7 and an oxygen outlet 8, which are communicated with the inner cavity of the rear electrode plate 3.

[0031] The electrolyte inlets are communicated with the inner cavity of the rear electrode plate 3 through electrolyte channels. The electrolyte channels are communicated with the cathode hydrogen production chamber and the anode oxygen production chamber of each electrolysis cell. The flow rate adjusting device is arranged at each electrolyte inlet. As shown in Figure 1 , the right side electrolyte inlets 5 are communicated with the inner cavity of the rear electrode plate 3 through the right side electrolyte channels 9. The left side electrolyte inlets 6 are communicated with the inner cavity of the rear electrode plate 3 through the left side electrolyte channels 10. Each electrolyte channel is communicated with the cathode hydrogen production chamber and the anode oxygen production chamber of each electrolysis cell. The hydrogen outlet 7 is communicated with the inner cavity of the rear electrode plate 3 through a hydrogen channel 11. The oxygen outlet 8 is communicated with the inner cavity of the rear electrode plate 3 through an oxygen channel 12. The hydrogen and oxygen produced by the electrolysis cell are transported to the hydrogen outlet 7 and the oxygen outlet 8 through the hydrogen channel 11 and the oxygen channel 12 and discharged.

[0032] Through theoretical analysis and experimental verification, the right side of the front pressing plate 4 is provided with 2-10 electrolyte inlets 5. In particular, the number of electrolyte inlets 5 is 3-6, which is the best. The left side of the front pressing plate 4 is provided with 2-10 electrolyte inlets 6. In particular, the number of electrolyte inlets 6 is 3-6, which is the best.

[0033] As shown in Figure 1 , in this embodiment, the right side of the front pressing plate 4 is provided with three electrolyte inlets 5. The left side of the front pressing plate 4 is provided with three electrolyte inlets 6. The upper end of the front pressing plate 4 is provided with two outlets: a hydrogen outlet 7 and an oxygen outlet 8. The electrolyte enters from the electrolyte inlets 5 and 6 on the left and right sides of the front pressing plate 4, enters the inner cavity of the rear electrode plate 3 through the electrolyte channels 9 and 10, enters the electrolysis cell in the tank through the inner cavity of the rear electrode plate 3, and performs electrolysis to produce hydrogen. The hydrogen produced in the electrolysis process is transported to the hydrogen outlet 7 through the hydrogen channel 11 and discharged. The oxygen produced is transported to the oxygen outlet 8 through the oxygen channel 12 and discharged.

[0034] The improvement of the above technical scheme is:

[0035] (1) For large alkaline electrolytic tanks, a plurality of electrolyte inlets and electrolyte channels are added, and a multi-channel alkaline electrolytic tank structure is designed, which increases the electrolyte circulation in the electrolytic tank and increases the internal heat exchange of the electrolytic tank, thereby saving energy and ensuring the normal operation of the electrolytic tank.

[0036] (2) For large alkaline electrolyzers, the provision of multiple electrolyte inlets provides feasibility for electrolyte circulation strategies under different working conditions. By changing the electrolyte flow rate of different electrolyte inlets through the flow rate adjustment device, an internal circulation heat exchange strategy can be realized, increasing the possibility of using different electrolyte circulation strategies when facing different working conditions.

[0037] (3) Small and medium-sized electrolytic cells are generally designed with a structure of one electrolyte inlet and one electrolyte channel. The electrolyte inlet provides electrolyte to all electrolytic cells in the cell. When the size of the electrolytic cell increases, this structure will cause uneven flow field distribution in a single electrolytic cell and generate a backflow zone at the lower inlet of the electrolytic cell. This application adds a multi-channel electrolyte circulation structure, which can effectively improve this uneven flow field distribution phenomenon.

[0038] (4) The additional electrolyte inlets are arranged on the left and right sides of the front end pressure plate 4 respectively. During the electrolyte circulation process, the electrolyte heat exchange on these two sides can be increased, so that the temperature distribution on both sides of the end pressure plate of the electrolytic cell is uniform along the depth direction of the cell body 1.

[0039] Furthermore, the electrolyte inlets 5 on the right side of the front pressure plate 4 can be evenly distributed on the right side of the front pressure plate 4, and the electrolyte inlets 6 on the left side of the front pressure plate 4 can be evenly distributed on the left side of the front pressure plate 4. Alternatively, the number of electrolyte inlets 5 on the right side and the number of electrolyte inlets 6 on the left side of the front pressure plate 4 can be the same, and their positions symmetrically distributed. This design can more accurately realize the electrolyte circulation strategy under different operating conditions, ensuring uniform flow field distribution and temperature distribution.

[0040] The basic structure of the electrolytic cell, the connection between the electrolyte channel and each electrolysis chamber, and the venting of the hydrogen and oxygen channels are all common knowledge in the field and can be understood by those skilled in the art, so they will not be elaborated here.

[0041] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A multi-channel liquid inlet exhaust structure for a large-scale alkaline water electrolyzer, characterized by, The electrolytic cell comprises a cell body, front and rear end plates arranged at both ends of the cell body, and front and rear end pressing plates arranged at both ends of the cell body, wherein the cell body, the front and rear end plates are all provided with inner cavities, the front and rear end plates are provided with radial holes, and a plurality of electrolytic cells are arranged in the inner cavities of the cell body; A plurality of electrolyte inlets are arranged on the right side of the front end pressing plate, and a plurality of electrolyte inlets are arranged on the left side of the front end pressing plate, wherein the electrolyte inlets are communicated with the inner cavities of the rear end plate, and the upper end of the front end pressing plate is provided with a hydrogen outlet and an oxygen outlet, wherein the hydrogen outlet and the oxygen outlet are communicated with the inner cavities of the rear end plate; The electrolyte inlets on the right side of the front end pressing plate are evenly distributed on the right side of the front end pressing plate; The electrolyte inlets on the left side of the front end pressing plate are evenly distributed on the left side of the front end pressing plate; Flow rate adjusting devices are arranged at the electrolyte inlets; The electrolyte enters from the electrolyte inlets on the left and right sides of the front end pressing plate, enters the inner cavities of the rear end plate through electrolyte channels, enters the electrolytic cells in the cell through the inner cavities of the rear end plate, and is subjected to electrolysis to produce hydrogen; the hydrogen produced in the electrolysis process is transported to the hydrogen outlet through a hydrogen channel and discharged, and the oxygen produced is transported to the oxygen outlet through an oxygen channel and discharged.

2. The multi-channel liquid inlet and gas outlet structure for a large alkaline water electrolyzer according to claim 1, characterized in that, The electrolyte inlets are communicated with the inner cavities of the rear end plate through electrolyte channels, and the electrolyte channels are communicated with the cathode hydrogen production chambers and the anode oxygen production chambers of the electrolytic cells.

3. The multi-channel liquid inlet and gas outlet structure for a large alkaline water electrolyzer according to claim 1, characterized in that, The hydrogen outlet is communicated with the inner cavities of the rear end plate through a hydrogen channel, and the oxygen outlet is communicated with the inner cavities of the rear end plate through an oxygen channel, and the hydrogen and oxygen produced by the electrolytic cells are transported to the hydrogen outlet and the oxygen outlet through the hydrogen channel and the oxygen channel and discharged.

4. The multi-channel liquid inlet and gas outlet structure for a large alkaline water electrolyzer according to claim 1, characterized in that, The right side of the front end pressing plate is provided with 2-10 electrolyte inlets.

5. The multi-channel liquid inlet and gas outlet structure for a large alkaline water electrolyzer according to claim 4, characterized in that, The right side of the front end pressing plate is provided with 3-6 electrolyte inlets.

6. The multi-channel liquid inlet and gas outlet structure for a large alkaline water electrolyzer of claim 1, wherein, The left side of the front end pressing plate is provided with 2-10 electrolyte inlets.

7. The multi-channel liquid inlet and gas outlet structure for a large alkaline water electrolyzer according to claim 6, characterized in that, The left side of the front end pressing plate is provided with 3-6 electrolyte inlets.

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