Asymmetric multi-channel liquid inlet and exhaust structure for large alkaline water electrolyzer

Abstract

The application relates to an asymmetric multi-channel liquid inlet and exhaust structure for a large alkaline water electrolysis tank, the electrolysis tank comprising a tank body, a front polar plate, a rear polar plate, a front end pressing plate and a rear end pressing plate, the tank 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 electrolysis small chambers are arranged in the inner cavities of the tank body; the lower end of the front end pressing plate is provided with a main electrolyte inlet, the middle part of the front end pressing plate is provided with a plurality of hydrogen side auxiliary electrolyte inlets and oxygen side auxiliary electrolyte inlets, the main electrolyte inlet, the hydrogen side auxiliary electrolyte inlets and the oxygen side auxiliary electrolyte inlets are communicated with the inner cavities of the rear polar plate, and the upper end of the front end pressing plate is provided with a hydrogen gas outlet and an oxygen gas outlet communicated with the inner cavities of the rear polar plate. Compared with the prior art, the hydrogen side auxiliary electrolyte inlets and the oxygen side auxiliary electrolyte inlets are additionally arranged, the hydrogen side auxiliary electrolyte channels are communicated with the cathode chambers, the oxygen side auxiliary electrolyte channels are communicated with the anode chambers, the temperature of one side can be controlled relatively independently, and the temperature distribution of the two poles of the electrolysis small chamber is uniform.

Description

TECHNICAL FIELD

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

[0002] With the increasing pressure of global climate warming, countries around the world focus on clean energy. Hydrogen energy, with its low carbon, high energy density, and wide sources, is the key to green development in the new era. Alkaline water electrolyzer is the key equipment for renewable energy water electrolysis hydrogen production technology. With the rapid development of hydrogen energy, alkaline water electrolyzer has gradually developed towards large-scale.

[0003] The water electrolyzer is composed of electrolytic cells in series. The industrial alkaline water electrolyzer generally has one alkali inlet to provide the required alkali for the electrolyzer. This liquid supply structure is suitable for small and medium-sized electrolyzers. However, with the large-scale development of alkaline water electrolyzers, the number of electrolytic cells in series will greatly increase, which will increase the flow field length inside the electrolyzer. A single alkali channel will affect the mass and heat transfer efficiency of the electrolyzer, and the uniformity of the flow field in the tank will be poor, resulting in uneven temperature distribution inside the electrolyzer, especially the temperature distribution of the cathode and anode of the electrolyzer, which will reduce the efficiency of the electrolyzer and shorten the service life of the electrolyzer.

[0004] Chinese patent CN212669809U discloses a new flow channel flow field structure water electrolyzer. By setting the intermediate polar plate, the tank body is separated, and the front half tank and the rear half tank form two independent cycles without interference. The essence is to divide the large-scale alkaline water electrolyzer into two small and medium-sized electrolyzers, and the liquid inlet and exhaust channel is not substantially improved. Therefore, in order to save energy and ensure the normal operation of the electrolyzer, a new 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 an asymmetric multi-channel liquid inlet and exhaust structure for a large-scale alkaline water electrolyzer.

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

[0007] An asymmetric multi-channel liquid inlet and exhaust structure for a large-scale alkaline water electrolyzer, the electrolyzer comprising a tank body, a front polar plate and a rear polar plate arranged at both ends of the tank body, and a front end pressing plate and a rear end pressing plate arranged at both ends of the tank body, the tank 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 a plurality of electrolytic cells are arranged in the inner cavity of the tank body.

[0008] The lower end of the front pressing plate is provided with a main electrolyte inlet, the middle part of the front pressing plate is provided with at least one hydrogen-side auxiliary electrolyte inlet and at least one oxygen-side auxiliary electrolyte inlet, the main electrolyte inlet, the hydrogen-side auxiliary electrolyte inlet and the oxygen-side auxiliary electrolyte inlet are communicated with the inner cavity of the rear polar plate, and 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 main electrolyte inlet is communicated with the inner cavity of the rear polar plate through a main electrolyte channel, the main electrolyte channel is communicated with the hydrogen production chamber of the cathode and the oxygen production chamber of the anode of each electrolysis cell, the hydrogen-side auxiliary electrolyte inlet is communicated with the inner cavity of the rear polar plate through a hydrogen-side auxiliary electrolyte channel, and the hydrogen-side auxiliary electrolyte channel is communicated with the hydrogen production chamber of the cathode of each electrolysis cell, and the oxygen-side auxiliary electrolyte inlet is communicated with the inner cavity of the rear polar plate through an oxygen-side auxiliary electrolyte channel, and the oxygen-side auxiliary electrolyte channel is communicated with 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 number of hydrogen-side auxiliary electrolyte inlets is 2.

[0012] Preferably, the number of oxygen-side auxiliary electrolyte inlets is 2.

[0013] Preferably, the hydrogen-side auxiliary electrolyte inlets are arranged on the right side of the middle part of the front pressing plate, and the oxygen-side auxiliary electrolyte inlets are arranged on the left side of the middle part of the front pressing plate.

[0014] Preferably, the plurality of hydrogen-side auxiliary electrolyte inlets are uniformly distributed on the right side of the middle part of the front pressing plate.

[0015] Preferably, the plurality of oxygen-side auxiliary electrolyte inlets are uniformly distributed on the left side of the middle part of the front pressing plate.

[0016] Preferably, flow rate adjusting devices are arranged at the main electrolyte inlet, the hydrogen-side auxiliary electrolyte inlet and the oxygen-side auxiliary electrolyte inlet.

[0017] Preferably, the control device is connected with each flow rate adjusting device and used for controlling each flow rate adjusting device.

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

[0019] (1) Add hydrogen side sub-electrolyte inlet and oxygen side sub-electrolyte inlet, the hydrogen side sub-electrolyte channel inside only communicates with the cathode chamber, and the oxygen side sub-electrolyte channel inside only communicates with the anode chamber, because the heat production of the electrolytic cell anode and cathode is different, the added hydrogen side sub-electrolyte channel and oxygen side sub-electrolyte channel can control the temperature of one side relatively independently, so that the temperature distribution of the electrolysis cell two poles is uniform.

[0020] (2) Add hydrogen side sub-electrolyte inlet and oxygen side sub-electrolyte inlet, the four sub-electrolyte inlets are added, so that the multi-channel electrolyte input is realized, compared with the single electrolyte channel structure design, the electrolyte circulation in the electrolytic cell is increased, and the heat exchange at the middle position of the electrolytic cell is increased.

[0021] (3) When the electrolytic cell only contains one electrolyte inlet, the flow field distribution in the single electrolysis cell is uneven, and a backflow area is generated at the lower end inlet of the electrolysis cell, and the multi-channel electrolyte input design can improve the flow field distribution in the single electrolysis cell to a certain extent.

[0022] (4) For a large alkaline electrolytic cell, the multi-channel electrolyte input design provides feasibility for the electrolyte circulation strategy under different working conditions, and through the flow rate adjusting device, the electrolyte flow rate of each channel can be changed, the internal circulation heat exchange strategy is realized, and the possibility of using different electrolyte circulation strategies under different working conditions is increased.

[0023] (5) The added sub-electrolyte inlet and channel have a channel path connected from the sub-electrolyte inlet to the rear pole plate, and connected from the rear pole plate to the electrolysis cell closest to the front pole plate in the cell, and the circuitous channel structure can increase the heat exchange at the middle position of the electrolysis cell deep in the electrolytic cell. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The figure is a structural schematic diagram of the present application;

[0025] The figure is a structural schematic diagram of the present application; DETAILED DESCRIPTION

[0026] The present application will be described in detail below in combination with the drawings and specific embodiments. The embodiments are implemented on the premise of the technical scheme of the present application, and detailed implementation modes and specific operation processes are given, but the protection scope of the present application is not limited to the following embodiments.

[0027] In the drawings, components of the same structure are denoted by the same reference numerals, and components having similar structures or functions are denoted by similar reference numerals. The size and thickness of each component shown in the drawings are arbitrarily shown, and the size and thickness of each component are not limited in the present application. In order to make the drawing clearer, the components are appropriately exaggerated in some places.

[0028] Embodiment 1:

[0029] The heat production of the cathode side and the anode side of the electrolytic cell is different, and this phenomenon is more obvious in a large-scale alkaline water electrolytic cell due to the flow field distribution. In order to improve the uneven temperature distribution of the cathode and the anode of the electrolytic cell, the present application provides a new type of multi-channel electrolytic cell flow field structure:

[0030] An asymmetric multi-channel liquid inlet and gas exhaust structure for a large-scale alkaline water electrolytic cell, the electrolytic cell comprising a cell body 1, a front polar plate 2 and a rear polar plate 3 arranged at both ends of the cell body 1, a front end pressing plate 4 and a rear end pressing plate arranged at both ends of the cell body 1, the cell body 1, the front polar plate 2 and the rear polar plate 3 are all provided with an inner cavity, the front polar plate 2 and the rear polar plate 3 are provided with radial holes, and a plurality of electrolytic small chambers are arranged in the inner cavity of the cell body 1.

[0031] The lower end of the front end pressing plate 4 is provided with a main electrolyte inlet 5, the middle part of the front end pressing plate 4 is provided with at least one hydrogen side auxiliary electrolyte inlet 6 and at least one oxygen side auxiliary electrolyte inlet 7, the main electrolyte inlet 5, the hydrogen side auxiliary electrolyte inlet 6 and the oxygen side auxiliary electrolyte inlet 7 are communicated with the inner cavity of the rear polar plate 3, and the upper end of the front end pressing plate 4 is provided with a hydrogen gas outlet 8 and an oxygen gas outlet 9, the hydrogen gas outlet 8 and the oxygen gas outlet 9 are communicated with the inner cavity of the rear polar plate 3.

[0032] The main electrolyte inlet 5 is communicated with the inner cavity of the rear polar plate 3 through a main electrolyte channel 10, the main electrolyte channel 10 is communicated with the cathode hydrogen production chamber and the anode oxygen production chamber of each electrolytic small chamber; the hydrogen side auxiliary electrolyte inlet 6 is communicated with the inner cavity of the rear polar plate 3 through a hydrogen side auxiliary electrolyte channel 11, the hydrogen side auxiliary electrolyte channel 11 is communicated with the cathode hydrogen production chamber of each electrolytic small chamber; the oxygen side auxiliary electrolyte inlet 7 is communicated with the inner cavity of the rear polar plate 3 through an oxygen side auxiliary electrolyte channel 12, the oxygen side auxiliary electrolyte channel 12 is communicated with the anode oxygen production chamber of each electrolytic small chamber; the hydrogen gas outlet 8 is communicated with the inner cavity of the rear polar plate 3 through a hydrogen gas channel 13, the oxygen gas outlet 9 is communicated with the inner cavity of the rear polar plate 3 through an oxygen gas channel 14, and the hydrogen gas and the oxygen gas generated by the electrolytic small chamber are transported to the hydrogen gas outlet 8 and the oxygen gas outlet 9 through the hydrogen gas channel 13 and the oxygen gas channel 14 for exhaust.

[0033] The main electrolyte inlet 5, the hydrogen side auxiliary electrolyte inlet 6 and the oxygen side auxiliary electrolyte inlet 7 are provided with flow rate adjusting devices, a control device is connected with each flow rate adjusting device, and each flow rate adjusting device is controlled so as to control the electrolyte flow rate flowing in from the main electrolyte inlet 5, the hydrogen side auxiliary electrolyte inlet 6 and the oxygen side auxiliary electrolyte inlet 7, respectively.

[0034] Each electrolyte channel connects to each electrolysis chamber. However, based on the traditional single electrolyte inlet design, this application adds a hydrogen-side auxiliary electrolyte inlet 6 and an oxygen-side auxiliary electrolyte inlet 7. The inner side of the hydrogen-side auxiliary electrolyte channel 11 is only connected to the cathode chamber, and the oxygen-side auxiliary electrolyte channel 12 is only connected to the anode chamber. Since the heat generation of the anode and cathode of the electrolytic cell is different, the added hydrogen-side auxiliary electrolyte inlet 6 and oxygen-side auxiliary electrolyte inlet 7 can control the temperature on one side relatively independently, so that the temperature distribution of the two electrodes of the electrolysis chamber is uniform.

[0035] It is understandable that the number of hydrogen-side auxiliary electrolyte inlets 6 and oxygen-side auxiliary electrolyte inlets 7 can be the same or different, and there can be one or more of them, and their arrangement is not limited to the left or right side. For example... Figure 1 As shown, in this embodiment, based on actual application conditions, two hydrogen-side auxiliary electrolyte inlets 6 and two oxygen-side auxiliary electrolyte inlets 7 are designed. The two hydrogen-side auxiliary electrolyte inlets 6 are located on the right side of the middle of the front end pressure plate 4, and the two oxygen-side auxiliary electrolyte inlets 7 are located on the left side of the middle of the front end pressure plate 4. The hydrogen outlet 8 and the oxygen outlet 9 are located at the upper end of the front end pressure plate 4. Furthermore, to ensure a uniform flow field, the number of hydrogen-side auxiliary electrolyte inlets 6 and oxygen-side auxiliary electrolyte inlets 7 can be the same. The hydrogen-side auxiliary electrolyte inlets 6 are evenly distributed on the right side of the middle of the front end pressure plate 4, and the oxygen-side auxiliary electrolyte inlets 7 are evenly distributed on the left side of the middle of the front end pressure plate 4, and the hydrogen-side auxiliary electrolyte inlets 6 and oxygen-side auxiliary electrolyte inlets 7 are symmetrically distributed.

[0036] During operation, a portion of the electrolyte enters the main electrolyte inlet 5, flows through the main electrolyte channel 10 into the inner cavity of the rear electrode plate 3, and then into the various electrolysis chambers within the electrolytic cell for hydrogen production. Another portion of the electrolyte enters the hydrogen-side auxiliary electrolyte inlet 6, flows through the hydrogen-side auxiliary electrolyte channel 11 into the inner cavity of the rear electrode plate 3, and then into the cathode chamber of each electrolysis chamber within the electrolytic cell. A third portion of the electrolyte enters the oxygen-side auxiliary electrolyte inlet 7, flows through the oxygen-side auxiliary electrolyte channel 12 into the inner cavity of the rear electrode plate 3, and then into the anode chamber of each electrolysis chamber within the electrolytic cell. The hydrogen produced during electrolysis is discharged through the hydrogen channel 13, and the oxygen produced is discharged through the oxygen channel 14.

[0037] The improvement to the above technical solution is:

[0038] (1) Add a hydrogen-side auxiliary electrolyte inlet 6 and an oxygen-side auxiliary electrolyte inlet 7. The inner side of the hydrogen-side auxiliary electrolyte channel 11 is only connected to the cathode chamber, and the inner side of the oxygen-side auxiliary electrolyte channel 12 is only connected to the anode chamber. Because the heat generation of the anode and cathode of the electrolytic cell is different, the added hydrogen-side auxiliary electrolyte channel 11 and oxygen-side auxiliary electrolyte channel 12 can control the temperature on one side relatively independently, so that the temperature distribution of the two electrodes of the electrolytic cell is uniform.

[0039] (2) Adding hydrogen-side auxiliary electrolyte inlet 6 and oxygen-side auxiliary electrolyte inlet 7, the addition of four auxiliary electrolyte inlets realizes multi-channel input of electrolyte. Compared with the single electrolyte channel structure design, the present invention increases the electrolyte circulation in the electrolytic cell and increases the heat exchange in the middle of the electrolytic cell.

[0040] (3) When the electrolytic cell contains only one electrolyte inlet, the flow field distribution in a single electrolytic cell is uneven, and a backflow zone will be generated at the lower inlet of the electrolytic cell. The design of multi-channel electrolyte input will improve the flow field distribution in the electrolytic cell to a certain extent by introducing electrolyte from the middle of a single electrolytic cell.

[0041] (4) For large alkaline electrolyzers, the design of multi-channel electrolyte input provides feasibility for electrolyte circulation strategies under different working conditions. By changing the electrolyte flow rate of each channel through the flow rate adjustment device, the internal circulation heat exchange strategy can be realized, increasing the possibility of using different electrolyte circulation strategies when facing different working conditions.

[0042] (5) The added auxiliary electrolyte inlet and channel have a channel path that connects from the auxiliary electrolyte inlet to the rear electrode plate 3, and in the cell, from the rear electrode plate 3 to the electrolysis chamber closest to the front electrode plate 2. This meandering channel structure can increase the heat exchange in the middle of the electrolysis chamber deep in the electrolysis cell.

[0043] 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.

[0044] 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. An asymmetric multi-channel liquid inlet exhaust structure for a large-scale alkaline water electrolyzer, characterized in that, The electrolytic cell comprises a cell body, a front polar plate and a rear polar plate arranged at both ends of the cell body, a front end pressing plate and a rear end pressing 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 a radial hole, and a plurality of electrolytic cells are arranged in the inner cavity of the cell body; The lower end of the front end pressing plate is provided with a main electrolyte inlet, the middle part of the front end pressing plate is provided with at least one hydrogen side auxiliary electrolyte inlet and at least one oxygen side auxiliary electrolyte inlet, the main electrolyte inlet, the hydrogen side auxiliary electrolyte inlet and the oxygen side auxiliary electrolyte inlet are communicated with the inner cavity of the rear polar plate, the upper end of the front end pressing plate is provided with a hydrogen gas outlet and an oxygen gas outlet, and the hydrogen gas outlet and the oxygen gas outlet are communicated with the inner cavity of the rear polar plate; The main electrolyte inlet is communicated with the inner cavity of the rear polar plate through a main electrolyte channel, the main electrolyte channel is communicated with the cathode hydrogen production chamber and the anode oxygen production chamber of each electrolytic cell, the hydrogen side auxiliary electrolyte inlet is communicated with the inner cavity of the rear polar plate through a hydrogen side auxiliary electrolyte channel, and the hydrogen side auxiliary electrolyte channel is communicated with the cathode hydrogen production chamber of each electrolytic cell; the oxygen side auxiliary electrolyte inlet is communicated with the inner cavity of the rear polar plate through an oxygen side auxiliary electrolyte channel, and the oxygen side auxiliary electrolyte channel is communicated with the anode oxygen production chamber of each electrolytic cell; Flow rate adjusting devices are arranged at the main electrolyte inlet, the hydrogen side auxiliary electrolyte inlet and the oxygen side auxiliary electrolyte inlet.

2. The asymmetric multi-channel liquid inlet and gas outlet structure for a large alkaline water electrolyzer according to claim 1, characterized in that, The hydrogen gas outlet is communicated with the inner cavity of the rear polar plate through a hydrogen gas channel, the oxygen gas outlet is communicated with the inner cavity of the rear polar plate through an oxygen gas channel, and the hydrogen gas and the oxygen gas generated by the electrolytic cell are transported to the hydrogen gas outlet and the oxygen gas outlet through the hydrogen gas channel and the oxygen gas channel for discharge.

3. The asymmetric multi-channel liquid inlet and gas outlet structure for a large alkaline water electrolyzer according to claim 1, characterized in that, The number of hydrogen side auxiliary electrolyte inlets is 2.

4. The asymmetric multi-channel liquid inlet and gas outlet structure for a large alkaline water electrolyzer of claim 1, wherein, The number of oxygen side auxiliary electrolyte inlets is 2.

5. The asymmetric multi-channel liquid inlet and gas outlet structure for a large alkaline water electrolyzer of claim 1, wherein, The hydrogen side auxiliary electrolyte inlets are arranged on the right side of the middle part of the front end pressing plate, and the oxygen side auxiliary electrolyte inlets are arranged on the left side of the middle part of the front end pressing plate.

6. The asymmetric multi-channel liquid inlet and gas outlet structure for a large alkaline water electrolyzer of claim 5, wherein, The plurality of hydrogen side auxiliary electrolyte inlets are uniformly distributed on the right side of the middle part of the front end pressing plate.

7. The asymmetric multi-channel liquid inlet and gas outlet structure for a large alkaline water electrolyzer of claim 5, wherein, The plurality of oxygen side auxiliary electrolyte inlets are uniformly distributed on the left side of the middle part of the front end pressing plate.

8. The asymmetric multi-channel liquid inlet and gas outlet structure for a large alkaline water electrolyzer of claim 1, wherein, The control device is connected with each flow rate adjusting device and is used for controlling each flow rate adjusting device.

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