An alkaline electrolyzer

Abstract

The utility model belongs to the alkaline water electrolysis hydrogen production technical field, concretely relates to a kind of alkaline electrolytic cell, including end pressing plate one and end pressing plate two, still include several electrolytic cells being set between end pressing plate one and end pressing plate two, end pressing plate one is provided with lye inlet and gas-liquid outlet, end pressing plate two is provided with recess cavity towards one side of electrolytic cell, single electrolytic cell includes two bipolar plates, and the pole frame of bipolar plate is provided with main flow port, lye flow port and gas-liquid flow port, lye inlet is communicated with recess cavity by main flow port, recess cavity is communicated with lye flow port, and lye flow port is communicated with the inside of the pole frame of bipolar plate by flow channel one, gas-liquid flow port is communicated with gas-liquid outlet, and gas-liquid flow port is communicated with the inside of the pole frame of bipolar plate by flow channel two, and flow channel one and flow channel two are all zigzag non-linear flow channel.The utility model can increase the fluid flow resistance and fluid pressure drop of electrolytic cell, and lye is evenly distributed, improve temperature consistency and current efficiency.

Description

Technical Field

[0001] This utility model belongs to the field of alkaline water electrolysis hydrogen production technology, specifically relating to an alkaline electrolytic cell. Background Technology

[0002] With the continuous improvement of alkaline electrolyzer technology, there is a growing demand for structural designs that ensure uniform fluid distribution and high current efficiency. Achieving uniform fluid distribution and ensuring consistent temperature improves the long-term reliability of the electrolyzer and reduces energy consumption. Higher current efficiency means less energy is consumed per unit of hydrogen produced during the production process, thus reducing production costs.

[0003] As alkaline electrolyzers gradually become larger, the 1,000 cubic meter alkaline electrolyzer has become the mainstream. The increase in the size of alkaline electrolyzers has led to an increase in the number of electrolyzer chambers, which has reduced the uniformity of fluid distribution inside the alkaline electrolyzer. At the same time, the increase in the number of electrolyzer chambers has led to an increase in the bypass shunt current, and the current efficiency has also decreased. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide an alkaline electrolytic cell that increases the fluid flow resistance and fluid pressure drop in the electrolysis chamber, ensures uniform distribution of alkali solution, and improves temperature consistency and current efficiency.

[0005] This utility model includes an end pressure plate one and an end pressure plate two, and also includes several electrolysis chambers disposed between the end pressure plate one and the end pressure plate two. The end pressure plate one is provided with an alkali inlet and a gas-liquid outlet. The side of the end pressure plate two facing the electrolysis chamber is provided with a cavity. Each electrolysis chamber includes two bipolar plates. The electrode frame of the bipolar plates is provided with a main flow channel, an alkali flow channel, and a gas-liquid flow channel. The alkali inlet is connected to the cavity through the main flow channel, the cavity is connected to the alkali flow channel, and the alkali flow channel is connected to the inner side of the electrode frame of the bipolar plate through a flow channel one. The gas-liquid flow channel is connected to the gas-liquid outlet, and the gas-liquid flow channel is connected to the inner side of the electrode frame of the bipolar plate through a flow channel two. Both the first and second flow channels are tortuous non-linear flow channels.

[0006] Furthermore, the flow channel one and flow channel two are arranged to extend in a direction inclined to the radial direction of the bipolar plate.

[0007] Furthermore, both flow channel one and flow channel two are serpentine.

[0008] Furthermore, the alkali flow channel is located in the lower part of the bipolar plate frame. The flow channel includes an arc-shaped channel one and an arc-shaped channel two. One end of the arc-shaped channel one is connected to the alkali flow channel, and the other end is connected to one end of the arc-shaped channel two. The other end of the arc-shaped channel two is connected to the inner side of the bipolar plate frame. The protrusion of the arc-shaped channel one faces the inner side of the bipolar plate frame, and the protrusion of the arc-shaped channel two faces the outer side of the bipolar plate frame.

[0009] Furthermore, the gas-liquid flow channel is located in the upper part of the bipolar plate frame. The flow channel two includes an arc-shaped channel three and an arc-shaped channel four. One end of the arc-shaped channel three is connected to the gas-liquid flow channel, and the other end is connected to one end of the arc-shaped channel four. The other end of the arc-shaped channel four is connected to the inner side of the bipolar plate frame. The protrusion of the arc-shaped channel three faces the inner side of the bipolar plate frame, and the protrusion of the arc-shaped channel four faces the outer side of the bipolar plate frame.

[0010] Furthermore, each side of the bipolar plate frame is provided with a flow channel 1, and a single bipolar plate frame has two or more alkali flow channel openings. Some of the alkali flow channel openings are connected to the inner side of the bipolar plate frame through the flow channel 1 on one side of the bipolar plate frame, while the other part of the alkali flow channel openings are connected to the inner side of the bipolar plate frame through the flow channel 1 on the other side of the bipolar plate frame.

[0011] Furthermore, flow channels are provided on both sides of the bipolar plate frame, and there are more than two gas-liquid flow channels on a single bipolar plate frame. Some of the gas-liquid flow channels are connected to the inner side of the bipolar plate frame through flow channel two on one side of the bipolar plate frame, while the other gas-liquid flow channels are connected to the inner side of the bipolar plate frame through flow channel two on the other side of the bipolar plate frame.

[0012] Furthermore, the side of the end pressure plate facing the electrolysis chamber is provided with a liquid inlet channel, the liquid inlet channel is positioned corresponding to the main channel opening and is connected to the concave cavity, and the main channel opening is connected to the concave cavity through the liquid inlet channel.

[0013] Furthermore, the side of the end plate facing the electrolysis chamber is also provided with a liquid outlet channel, which corresponds to the position of the alkali solution flow channel and is connected to the concave cavity. The concave cavity is connected to the alkali solution flow channel through the liquid outlet channel.

[0014] Furthermore, the alkali inlet is provided with at least two.

[0015] The beneficial effects of this invention are as follows: when the alkali solution enters the alkaline electrolytic cell through the alkali solution inlet, it first flows along the main flow channel to the concave cavity of end plate two, and then flows back from the concave cavity into the alkali solution flow channel to distribute it to each electrolysis chamber. This ensures that the alkali solution and gas-liquid flow follow the same direction along the flow path of several electrolysis chambers, guaranteeing consistent flow resistance loss and improving fluid distribution uniformity. Furthermore, since both flow channels one and two are tortuous non-linear flow channels, the resistance when the alkali solution enters and the gas-liquid flow out of the electrolysis chambers is increased, as is the fluid pressure drop in each electrolysis chamber, effectively improving the fluid distribution uniformity of each electrolysis chamber. This also improves the temperature uniformity of the alkaline electrolytic cell, enhances its operational safety and reliability, and reduces its energy consumption. Compared to a straight structure, the tortuous, non-linear flow channels one and two create longer inlet and outlet channels, which increases the resistance of these channels, thereby reducing bypass current and allowing more current to flow to the cathode and anode electrodes for water electrolysis to produce hydrogen, thus improving the current efficiency of the alkaline electrolyzer. Attached Figure Description

[0016] Figure 1 This is a schematic diagram showing the exploded structure of the alkaline electrolytic cell of this utility model.

[0017] Figure 2 This is a flow distribution diagram for the electrolysis chamber of this utility model.

[0018] Figure 3 This is a potential distribution model diagram of this utility model.

[0019] Figure 4 This is a model diagram of the electrolyte potential of this utility model.

[0020] Figure 5 This is a graph showing the change in current efficiency of this utility model.

[0021] Figure 6 The flow distribution diagram for the electrolysis chamber is shown in Comparative Example 1.

[0022] Figure 7 The diagram shows the potential distribution model for Comparative Example 1.

[0023] Figure 8 This is a diagram of the electrolyte potential model for Comparative Example 1.

[0024] Figure 9 The graph shows the change in current efficiency as shown in Comparative Example 1.

[0025] In the diagram: 1. End pressure plate one; 11. Alkali inlet; 12. Gas-liquid outlet; 2. End pressure plate two; 21. Cavity; 22. Liquid inlet channel; 23. Liquid outlet channel; 3. Electrolysis chamber; 31. Bipolar plate; 311. Main flow channel opening; 312. Alkali flow channel opening; 313. Gas-liquid flow channel opening; 314. Flow channel one; 3141. Arc-shaped channel one; 3142. Arc-shaped channel two; 315. Flow channel two; 3151. Arc-shaped channel three; 3152. Arc-shaped channel four; 32. Gasket; 33. Cathode electrode; 34. Diaphragm; 35. Anode electrode. Detailed Implementation

[0026] like Figure 1 As shown, this utility model provides an alkaline electrolytic cell, including a first end plate 1, a second end plate 2, and several electrolytic chambers 3 disposed between the first end plate 1 and the second end plate 2. The first end plate 1 is provided with an alkali inlet 11 and a gas-liquid outlet 12, which are connected through the first end plate 1. The second end plate 2 has a cavity 21 on its side facing the electrolytic chamber 3. Each electrolytic chamber 3 includes two bipolar plates 31. The bipolar plate 31 has a main flow channel 311, an alkali flow channel 312, and a gas-liquid flow channel 313 on its frame. The main flow channel 311 corresponds to the position of the alkali inlet 11, and the gas-liquid flow channel 313 corresponds to the position of the gas-liquid outlet 12. The alkali inlet 11 is connected to the cavity 21 through the main channel 311, the cavity 21 is connected to the alkali flow channel 312, and the alkali flow channel 312 is connected to the inner side of the bipolar plate 31 through the first flow channel 314. The gas-liquid flow channel 313 is connected to the gas-liquid outlet 12, and the gas-liquid flow channel 313 is connected to the inner side of the bipolar plate 31 through the second flow channel 315. The first flow channel 314 and the second flow channel 315 are both tortuous non-linear flow channels. The path length of the first flow channel 314 is greater than the straight-line distance between the two ends of the first flow channel 314, and the same applies to the second flow channel 315.

[0027] The electrolysis chamber 3 of this application has the same structure as the prior art. Besides the two bipolar plates 31, it also includes a gasket 32, a cathode electrode 33, a diaphragm 34, and an anode electrode 35. The gasket 32 ​​is disposed between the two bipolar plates 31 and has through holes corresponding to the number and position of the main flow channel 311, the alkali flow channel 312, and the gas-liquid flow channel 313. The bipolar plates 31 provide alkali flow channels through the main flow channel 311, the alkali flow channel 312, and the gas-liquid flow channel 313. The cathode electrode 33 generates hydrogen gas, and the anode electrode 35 generates oxygen gas. The diaphragm 34 isolates hydrogen and oxygen gas while allowing OH- ions to pass through. The region located inside the bipolar plate 31 frame forms the cavity of the electrolysis chamber 3.

[0028] Based on the above configuration, when the alkali solution enters the alkaline electrolytic cell through the alkali solution inlet 11, it first flows along the main flow channel 311 to the cavity 21 of the second end plate, and then enters the alkali solution flow channel 312 from the cavity 21, returning and distributing to each electrolysis chamber 3. This ensures that the alkali solution and gas-liquid flow follow the same direction along the flow path of several electrolysis chambers 3, guaranteeing consistent flow resistance loss and improving fluid distribution uniformity. Furthermore, since both flow channels 314 and 315 are tortuous, non-linear flow channels, they increase the resistance when the alkali solution enters and exits the electrolysis chambers 3, as well as the fluid pressure drop in each electrolysis chamber 3, effectively improving the fluid distribution uniformity in each electrolysis chamber 3. This improves the temperature uniformity of the alkaline electrolytic cell, enhances its operational safety and reliability, and reduces its energy consumption. Compared to a straight structure, the tortuous non-linear flow channels 314 and 315 form longer inlet and outlet channels, which can increase the resistance of the inlet and outlet channels, thereby reducing the bypass current and allowing more current to flow to the cathode electrode 33 and anode electrode 35 for water electrolysis to produce hydrogen, thus improving the current efficiency of the alkaline electrolyzer.

[0029] The flow channel 314 and flow channel 315 extend in a direction inclined to the radial direction of the bipolar plate 31, which is beneficial for setting a longer flow channel 314 and flow channel 315.

[0030] The flow channel 314 and flow channel 315 can be serrated, arc-shaped or serpentine, preferably serpentine, which has more bending points than arc-shaped, which is conducive to forming a longer path channel, and the bending points have a smoother curve transition.

[0031] In the alkaline electrolytic cell, the bipolar plates 31 are arranged vertically. In this invention, as... Figure 1 As shown, the alkali inlet 312 is located in the lower part of the bipolar plate 31's frame, that is, the alkali inlet 312 is located in the lower end region of the alkaline electrolytic cell. The first flow channel 314 includes an arc-shaped channel 3141 and an arc-shaped channel 3142. One end of the arc-shaped channel 3141 is connected to the alkali inlet 312, and the other end is connected to one end of the arc-shaped channel 3142. The other end of the arc-shaped channel 3142 is connected to the inner side of the bipolar plate 31's frame. The protrusion of the arc-shaped channel 3141 faces the inner side of the bipolar plate 31's frame, and the protrusion of the arc-shaped channel 3142 faces the outer side of the bipolar plate 31's frame. Figure 1 From a visual perspective, the protrusion of arc-shaped channel one 3141 faces upward, while the protrusion of arc-shaped channel two 3142 faces downward. Since the alkali flow port 312 is located in the lower part of the bipolar plate 31 frame, the arrangement of arc-shaped channel one 3141 and arc-shaped channel two 3142 effectively ensures the resistance when the alkali enters the electrolysis chamber 3.

[0032] like Figure 1As shown, the gas-liquid flow port 313 is located in the upper part of the bipolar plate 31's frame, that is, the gas-liquid flow port 313 is located in the upper part of the alkaline electrolytic cell. The flow channel 315 includes an arc-shaped channel 3151 and an arc-shaped channel 4 3152. One end of the arc-shaped channel 3151 is connected to the gas-liquid flow port 313, and the other end is connected to one end of the arc-shaped channel 4 3152. The other end of the arc-shaped channel 4 3152 is connected to the inner side of the bipolar plate 31's frame. The protrusion of the arc-shaped channel 3151 faces the inner side of the bipolar plate 31's frame, and the protrusion of the arc-shaped channel 4 3152 faces the outer side of the bipolar plate 31's frame. Figure 1 From a visual perspective, the protrusion of arc-shaped channel three 3151 faces downwards, while the protrusion of arc-shaped channel four 3152 faces upwards. Since the alkali flow channel 312 is located in the upper part of the bipolar plate 31 frame, the arrangement of the aforementioned arc-shaped channel one 3141 and arc-shaped channel two 3142 effectively ensures the resistance when gas and liquid are discharged along the electrolysis chamber 3.

[0033] In this invention, both sides of the bipolar plate 31 frame are provided with flow channels 314. There are two or more alkaline solution flow ports 312 on a single bipolar plate 31 frame. Some of the alkaline solution flow ports 312 are connected to the inner side of the bipolar plate 31 frame through the flow channel 314 on one side of the bipolar plate 31 frame, and the other part of the alkaline solution flow ports 312 are connected to the inner side of the bipolar plate 31 frame through the flow channel 314 on the other side of the bipolar plate 31 frame, so as to form two or more alkaline solution inlet channels on a single bipolar plate 31. Both sides of the bipolar plate 31 frame are provided with flow channels 315. There are more than two gas-liquid flow ports 313 on a single bipolar plate 31 frame. Some of the gas-liquid flow ports 313 are connected to the inner side of the bipolar plate 31 frame through the flow channel 315 on one side of the bipolar plate 31 frame, and the other part of the gas-liquid flow ports 313 are connected to the inner side of the bipolar plate 31 frame through the flow channel 315 on the other side of the bipolar plate 31 frame, so as to form more than two gas-liquid discharge channels on a single bipolar plate 31.

[0034] like Figure 1 As shown, there are two flow channels 314 and two flow channels 315 on one side of the bipolar plate 31 frame. There are four alkaline liquid flow ports 312 and four gas-liquid flow ports 313 on a single bipolar plate 31. This increases the resistance when alkaline liquid enters the electrolysis chamber 3 and when gas and liquid flow out of the electrolysis chamber 3, thus ensuring the speed of alkaline liquid entering the electrolysis chamber 3 and gas and liquid exiting the electrolysis chamber 3.

[0035] The end pressure plate 2 has an inlet channel 22 on the side facing the electrolysis chamber 3. The inlet channel 22 corresponds to the main flow channel 311, and one end of the inlet channel 22 is laterally connected to the concave cavity 21. The main flow channel 311 is specifically connected to the concave cavity 21 through the inlet channel 22. The end pressure plate 2 also has an outlet channel 23 on the side facing the electrolysis chamber 3. The outlet channel 23 corresponds to the alkali flow channel 312, and one end of the outlet channel 23 is laterally connected to the concave cavity 21. The concave cavity 21 is connected to the alkali flow channel 312 through the outlet channel 23.

[0036] The alkali inlet 11 is provided with at least two, and the number of main channel ports 311 and the number of liquid inlet channels 22 on a single bipolar plate 31 are the same as the number of alkali inlets 11.

[0037] like Figure 2 As shown, the range ratio of the flow deviation results of this invention is 1.11. Through electrochemical simulation, the potential distribution of the alkaline electrolytic cell of this invention is as follows: Figure 3 As shown, the electrolyte potential is as follows Figure 4 As shown, the current efficiency is as follows Figure 5 As shown, it is approximately 98%.

[0038] Comparative Example 1 The alkaline electrolytic cell of Comparative Example 1 has the same specifications and number of electrolysis chambers as this utility model. The difference is that the flow channel one and flow channel two of Comparative Example 1 are straight flow channels commonly found in the prior art.

[0039] like Figure 6 As shown, the range ratio of the flow deviation results for Comparative Example 1 is 1.36. Through electrochemical simulation, the potential distribution of the alkaline electrolyzer in Comparative Example 1 is as follows: Figure 7 As shown, the electrolyte potential is as follows Figure 8 As shown, the current efficiency is as follows Figure 9 As shown, the current efficiency is approximately 96%. Therefore, compared to Comparative Example 1, the current efficiency of the alkaline electrolyzer of this invention is improved by 2%.

[0040] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of protection of this application is limited to these examples; within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of one or more embodiments of this application as described above, which are not provided in detail for the sake of brevity.

[0041] One or more embodiments in this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of one or more embodiments in this application should be included within the protection scope of this application.

Claims

1. An alkaline electrolyzer characterized by, The device includes a first end plate (1) and a second end plate (2), and also includes several electrolytic chambers (3) disposed between the first end plate (1) and the second end plate (2). The first end plate (1) is provided with an alkali inlet (11) and a gas-liquid outlet (12). The second end plate (2) has a cavity (21) on the side facing the electrolytic chamber (3). Each electrolytic chamber (3) includes two bipolar plates (31). The bipolar plates (31) have a main flow channel (311), an alkali flow channel (312), and a gas-liquid flow channel (313) on their frames. 3) The alkali inlet (11) is connected to the cavity (21) through the main channel (311), the cavity (21) is connected to the alkali flow channel (312), and the alkali flow channel (312) is connected to the inner side of the bipolar plate (31) through the first flow channel (314). The gas-liquid flow channel (313) is connected to the gas-liquid outlet (12), and the gas-liquid flow channel (313) is connected to the inner side of the bipolar plate (31) through the second flow channel (315). The first flow channel (314) and the second flow channel (315) are both tortuous non-linear flow channels.

2. The alkaline electrolyzer of claim 1, wherein The flow channel one (314) and flow channel two (315) are arranged in a direction inclined to the radial direction of the bipolar plate (31).

3. The alkaline electrolyzer of claim 1 or 2, wherein Both flow channel one (314) and flow channel two (315) are serpentine.

4. The alkaline electrolyzer of claim 3, wherein the anode is a titanium anode. The alkali flow channel (312) is located in the lower part of the bipolar plate (31) frame. The first flow channel (314) includes an arc-shaped channel (3141) and an arc-shaped channel (3142). One end of the arc-shaped channel (3141) is connected to the alkali flow channel (312), and the other end is connected to one end of the arc-shaped channel (3142). The other end of the arc-shaped channel (3142) is connected to the inner side of the bipolar plate (31) frame. The protrusion of the arc-shaped channel (3141) faces the inner side of the bipolar plate (31) frame, and the protrusion of the arc-shaped channel (3142) faces the outer side of the bipolar plate (31) frame.

5. The alkaline electrolyzer of claim 3, wherein the anode is a titanium anode coated with a layer of iridium oxide. The gas-liquid flow port (313) is located in the upper part of the bipolar plate (31) frame. The flow channel two (315) includes an arc-shaped channel three (3151) and an arc-shaped channel four (3152). One end of the arc-shaped channel three (3151) is connected to the gas-liquid flow port (313), and the other end is connected to one end of the arc-shaped channel four (3152). The other end of the arc-shaped channel four (3152) is connected to the inner side of the bipolar plate (31) frame. The protrusion of the arc-shaped channel three (3151) faces the inner side of the bipolar plate (31) frame, and the protrusion of the arc-shaped channel four (3152) faces the outer side of the bipolar plate (31) frame.

6. The alkaline electrolyzer of any one of claims 1, 2, 4, 5, wherein, Both sides of the bipolar plate (31) frame are provided with flow channels (314). There are two or more alkaline flow channels (312) on a single bipolar plate (31) frame. Some alkaline flow channels (312) are connected to the inner side of the bipolar plate (31) frame through flow channels (314) on one side of the bipolar plate (31) frame, and other alkaline flow channels (312) are connected to the inner side of the bipolar plate (31) frame through flow channels (314) on the other side of the bipolar plate (31) frame.

7. The alkaline electrolyzer of claim 6, wherein the cathode is a carbon cathode. Both sides of the bipolar plate (31) frame are provided with flow channels 2 (315). There are more than two gas-liquid flow ports (313) on a single bipolar plate (31) frame. Some gas-liquid flow ports (313) are connected to the inner side of the bipolar plate (31) frame through flow channel 2 (315) on one side of the bipolar plate (31) frame, and other gas-liquid flow ports (313) are connected to the inner side of the bipolar plate (31) frame through flow channel 2 (315) on the other side of the bipolar plate (31) frame.

8. The alkaline electrolyzer of any one of claims 1, 2, 4, 5, 7, characterized in that, The end plate 2 (2) is provided with a liquid inlet channel (22) on the side facing the electrolysis chamber (3). The liquid inlet channel (22) corresponds to the position of the main channel opening (311) and is connected to the cavity (21). The main channel opening (311) is connected to the cavity (21) through the liquid inlet channel (22).

9. The alkaline electrolyzer of claim 8, wherein the cathode is a carbon cathode. The end plate 2 (2) facing the electrolysis chamber (3) is also provided with a liquid outlet channel (23). The liquid outlet channel (23) corresponds to the position of the alkaline solution flow port (312) and is connected to the cavity (21). The cavity (21) is connected to the alkaline solution flow port (312) through the liquid outlet channel (23).

10. The alkaline electrolyzer of any one of claims 1, 2, 4, 5, 7, characterized in that, The alkali inlet (11) is provided with at least two.

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