Multi-pipeline shunting device and method for near-zero starting of alkaline electrolytic cell

Abstract

The invention discloses a multi-pipeline shunting device for near-zero starting of an alkaline electrolytic cell, and belongs to the technical field of electrolytic cells for hydrogen production through water electrolysis. An alkaline electrolytic cell module is formed by connecting a plurality of small electrolytic chambers which are regularly arranged in parallel, and a small heating device is arranged between any two adjacent small electrolytic chambers; each small electrolysis chamber is provided with a cathode liquid inlet and an anode liquid inlet; and each small electrolysis chamber is provided with a cathode liquid outlet and an anode liquid outlet. Impact of starting current on key components such as electrodes and diaphragms of the electrolytic cell is greatly reduced by applying a multi-pipeline shunting technology, and the service life of the electrolytic cell is prolonged; the lye is conveyed through multiple pipelines simultaneously, and the temperature of the electrolyte is accurately adjusted in a stepped manner by combining small heating devices arranged in the pipelines, so that the electrolytic bath is quickly started. The hydrogen production efficiency can be improved, the unit-position hydrogen production cost is reduced, the overall performance of the alkaline electrolytic cell is improved, and wide application of the alkaline water electrolysis hydrogen production technology is promoted.

Description

Technical Field

[0001] The invention relates to the technical field of electrolytic cells for producing hydrogen by water electrolysis, and in particular to a multi-pipeline flow diversion device and method for near-zero startup of an alkaline electrolytic cell. Background Art

[0002] In today's hydrogen production field, alkaline electrolyzers have become widely used water electrolysis hydrogen production equipment due to their mature technology and relatively low cost. It uses alkaline electrolyte and direct current to electrolyze water into hydrogen and oxygen, and plays an important role in energy storage and conversion scenarios such as renewable energy generation surplus power consumption and distributed energy systems. In actual operation, alkaline electrolyzers often restart after shutdown, and cold start is one of the common methods. It is of great significance for the flexible operation of equipment under different working conditions, such as restarting during the day after shutdown during the night power trough period, or resuming after sudden power outages. However, there are many problems with traditional cold start technology. On the one hand, the startup time is long, and it takes several hours to increase the electrolyte temperature and establish stable electrode reaction conditions, which is difficult to meet the timeliness requirements of hydrogen production; the energy consumption is also high, and heating the electrolyte consumes a lot of energy, which is not in line with the trend of energy conservation and emission reduction. On the other hand, there is a high risk of electrode damage. Rapid changes in electrolyte temperature and changes in electrode surface reaction conditions can easily cause stress on the electrode and cause structural damage, affecting its service life and overall performance. The startup stability is poor, and parameters such as electrolyte conductivity and bubble behavior are unstable, resulting in large fluctuations in current efficiency and unstable hydrogen production output, which brings problems to subsequent gas storage and use.

[0003] Therefore, it is a technical problem that those skilled in the art urgently need to solve to provide a multi-pipeline shunt device and method for near-zero start-up of an alkaline electrolyzer, which can achieve rapid start-up of the electrolyzer, improve hydrogen production efficiency and improve the overall performance of the alkaline electrolyzer. Summary of the invention

[0004] The present invention aims to solve many problems of the traditional cold start method of the alkaline electrolyzer. The present invention uses multi-pipeline shunt technology to greatly reduce the impact of the starting current on the key components of the electrolyzer, such as the electrodes and diaphragms, to extend their service life and ensure long-term stable operation; the alkali solution is transported through multiple pipelines at the same time and the electrolyte temperature is accurately adjusted in a step-by-step manner in combination with a small heating device built into the pipeline, so as to achieve rapid start-up of the electrolyzer, meet the high requirements for the timeliness of hydrogen production such as renewable energy power generation and hydrogen production, and improve energy utilization efficiency; at the same time, the electrolyte is heated in a step-by-step manner, which can not only make the electrolyte temperature in the entire module electrolyzer device evenly distributed, but also can make the electrolyte at the outlet cool down, avoiding the use of cooling devices. Ultimately, this technology reduces the mechanical stress and electrical loss of the equipment, reduces the failure rate and maintenance costs, improves the hydrogen production efficiency, reduces the unit hydrogen production cost, improves the overall performance of the alkaline electrolyzer, and promotes the widespread application of alkaline water electrolysis hydrogen production technology.

[0005] To this end, an object of the present invention is to provide a multi-pipeline shunt device for near-zero startup of an alkaline electrolyzer, which is characterized by including an alkaline electrolyzer module;

[0006] Among them, the alkaline electrolyzer module is composed of a plurality of regularly arranged electrolysis cells connected in parallel, and a small heating device is provided between any two adjacent electrolysis cells;

[0007] Each electrolysis cell is provided with a cathode liquid inlet and an anode liquid inlet. A plurality of the cathode liquid inlets are connected in parallel through a cathode liquid inlet main pipeline, and a plurality of the anode liquid inlets are connected in parallel through an anode liquid inlet main pipeline;

[0008] Each electrolysis cell is provided with a cathode liquid outlet and an anode liquid outlet. A plurality of the cathode liquid outlets are connected in parallel through a cathode liquid outlet main pipeline, and a plurality of the anode liquid outlets are connected in parallel through an anode liquid outlet main pipeline.

[0009] In the present invention, the electrolysis cell is used for electrolysis reaction, and the heating device is used for heating the electrolyzer. The temperatures of the small heating devices from top to bottom of the electrolyzer are set to 25°C, 45°C, 65°C, 85°C, and 95°C in sequence, so that the temperature distribution of the alkali liquid in all electrolysis cells is more uniform. The radiant heat generated during the electrolysis process will be higher than 95°C. When the alkali liquid circulates to the heating device at 25°C, it will be cooled, so that the temperature of the electrolyte in the entire module is maintained at 95°C. In addition, due to the small chamber of the cell, the temperature required for electrolysis can be reached faster, realizing near-zero cold startup.

[0010] The present invention realizes the uniform distribution and rapid circulation of the electrolyte by setting multiple pipelines to shunt the electrolyte among multiple electrolysis cells.

[0011] Further, the cathode liquid inlet main pipeline is connected to a cathode alkali liquid tank, and the anode liquid inlet main pipeline is connected to an anode alkali liquid tank.

[0012] Further, it further includes a gas-liquid separator device, and the gas-liquid separation device includes a cathode gas-liquid separation device and an anode gas-liquid separation device;

[0013] The cathode liquid outlet main pipeline is connected to the cathode gas-liquid separation device;

[0014] The anode liquid outlet main pipeline is connected to the anode gas-liquid separation device.

[0015] Furthermore, the cathode gas-liquid separation device is provided with a cathode gas outlet and a cathode liquid outlet, and the cathode gas outlet is located above the cathode liquid outlet;

[0016] The anode gas-liquid separation device is provided with an anode gas outlet and an anode liquid outlet, and the anode gas outlet is located above the anode liquid outlet.

[0017] In the present invention, after the electrochemical reaction occurs in each electrolysis cell, the generated H 2 / O 2 respectively accompanies the alkaline solution and exits from the cathode / anode liquid outlet, and then converges into the cathode / anode gas main pipeline respectively and is discharged. After gas-liquid separation, high-concentration H 2 and O 2 .

[0018] The present invention also provides a method for near-zero startup of an alkaline electrolyzer, comprising the following steps:

[0019] (1) Inject the alkaline electrolyte in the alkaline electrolyte tank into the electrolysis cells through the total liquid inlet pipeline, so that the electrolyte is evenly distributed among a plurality of electrolysis cells;

[0020] (2) Start the small heating device to heat the electrolysis cells, so that the alkaline electrolyzer module can quickly reach the electrolysis temperature during startup, realizing near-zero startup.

[0021] Furthermore, the heating temperature of the small heating device is 25-95 °C.

[0022] The beneficial effects of the present invention are as follows:

[0023] 1. Through the multi-pipeline shunt technology, the present invention enables the electrolyte to be evenly distributed and quickly circulated among multiple electrolysis cells, improving the electrolysis efficiency and product purity. The multi-pipeline shunt method can evenly distribute the electrolyte into each electrolysis cell, making the distribution of the electrolyte in the electrolyzer more uniform. At the same time, the multi-pipeline shunt technology can also accelerate the circulation speed of the electrolyte, enabling the electrolyte to reach the electrolysis cells faster, thereby improving the electrolysis efficiency. In addition, the multi-pipeline shunt technology can also reduce the residence time of the electrolyte in the electrolyzer, thereby reducing the pollution and impurity accumulation of the electrolyte in the electrolyzer and improving the product purity. Therefore, the multi-pipeline shunt technology plays an important role in improving the electrolysis efficiency and product purity.

[0024] 2. Through the synergistic effect of the heating device and multi-pipeline shunt, the electrolytic cell can quickly reach the electrolysis temperature during startup, achieving near-zero startup, reducing energy consumption and time costs. In the present invention, the heating device can heat the electrolytic cell, enabling the electrolytic cell to quickly reach the electrolysis temperature during startup, thereby reducing startup time and energy consumption. At the same time, the multi-pipeline shunt technology can accelerate the circulation speed of the electrolyte, enabling the electrolyte to reach the electrolysis compartments faster, thereby accelerating the startup speed of the electrolytic cell. The synergistic effect of the heating device and the multi-pipeline shunt technology can also reduce the residence time of the electrolyte in the electrolytic cell, thereby reducing the pollution of the electrolyte in the electrolytic cell and the accumulation of impurities, and improving the purity of the product. Therefore, the synergistic effect of the heating device and the multi-pipeline shunt technology plays an important role in reducing energy consumption and time costs.

[0025] 3. Through the multi-pipeline shunt technology, the present invention reduces the generation of electrochemical corrosion during electrolysis and extends the service life of the equipment. In the present invention, the multi-pipeline shunt can evenly distribute the electrolyte to each electrolysis compartment, thereby reducing the local overheating and local electrochemical corrosion of the electrolyte in the electrolytic cell. In addition, the multi-pipeline shunt technology can also accelerate the circulation speed of the electrolyte, enabling the electrolyte to reach the electrolysis compartments faster, thereby reducing the residence time of the electrolyte in the electrolytic cell and reducing the generation of electrochemical corrosion during electrolysis. Therefore, the multi-pipeline shunt technology plays an important role in extending the service life of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings described below are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the provided drawings without creative efforts.

[0027] Figure 1 Schematic structural diagram of a multi-pipeline shunt device for near-zero startup of an alkaline electrolytic cell;

[0028] Figure 2 Partial enlarged schematic diagram of a multi-pipeline shunt device for near-zero startup of an alkaline electrolytic cell;

[0029] In the accompanying drawings, the list of structures represented by each reference numeral is as follows: 1 - electrolysis cell, 2 - small heating device, 3 - total cathode liquid inlet pipeline, 4 - total anode liquid inlet pipeline, 5 - cathode liquid inlet, 6 - anode liquid inlet, 7 - cathode liquid outlet, 8 - anode liquid outlet, 9 - total cathode liquid outlet pipeline, 10 - total anode liquid outlet pipeline, 11 - cathode gas outlet, 12 - anode gas outlet, 13 - cathode gas-liquid separation device, 14 - anode gas-liquid separation device, 15 - cathode liquid outlet, 16 - anode liquid outlet. Detailed implementation manners

[0030] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present invention, and should not be construed as a limitation to the present invention.

[0031] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention.

[0032] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.

[0033] In the present invention, unless otherwise clearly defined and limited, the terms "mounted", "connected", "connected with", "fixed" and other terms should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] In the present invention, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may include direct contact between the first and second features, or may include the first and second features not being in direct contact but in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the horizontal height of the first feature is less than that of the second feature.

[0035] Example 1

[0036] A multi-pipeline shunt device for near-zero start of an alkaline electrolyzer, comprising an alkaline electrolyzer module;

[0037] Wherein, the alkaline electrolyzer module is composed of a plurality of regularly arranged electrolysis cells 1 connected in parallel, and a small heating device 2 is provided between any two adjacent electrolysis cells 1;

[0038] Each electrolysis cell 1 is provided with a cathode liquid inlet 5 and an anode liquid inlet 6. A plurality of cathode liquid inlets 5 are connected in parallel through a cathode liquid inlet main pipeline 3, and a plurality of anode liquid inlets 6 are connected in parallel through an anode liquid inlet main pipeline 4;

[0039] Each electrolysis cell 1 is provided with a cathode liquid outlet 7 and an anode liquid outlet 8. A plurality of cathode liquid outlets 7 are connected in parallel through a cathode liquid outlet main pipeline 9, and a plurality of anode liquid outlets 8 are connected in parallel through an anode liquid outlet main pipeline 10.

[0040] The present invention realizes the uniform distribution and rapid circulation of the electrolyte by providing multiple pipelines to shunt the electrolyte among multiple electrolysis cells.

[0041] In some embodiments, the cathode liquid inlet main pipeline 3 is connected to a cathode caustic solution tank, and the anode liquid inlet main pipeline 4 is connected to an anode caustic solution tank.

[0042] In some embodiments, it further includes a gas-liquid separator device, and the gas-liquid separation device includes a cathode gas-liquid separation device 13 and an anode gas-liquid separation device 14;

[0043] The cathode liquid outlet main pipeline 9 is connected to the cathode gas-liquid separation device 13;

[0044] The anode liquid outlet main pipeline 10 is connected to the anode gas-liquid separation device 14.

[0045] In some other embodiments, the cathode gas-liquid separation device 13 is provided with a cathode gas outlet 11 and a cathode liquid outlet 15, and the cathode gas outlet 11 is located above the cathode liquid outlet 15;

[0046] The anode gas-liquid separation device 14 is provided with an anode gas outlet 12 and an anode liquid outlet 16, and the anode gas outlet 12 is located above the anode liquid outlet 16.

[0047] In the present invention, after the electrochemical reaction occurs in each electrolysis cell, H 2 / O 2 respectively accompany the lye to go out from the cathode / anode liquid outlet, and then respectively converge into the cathode / anode gas main pipeline and are discharged. After gas-liquid separation, high-concentration H 2 and O 2 .

[0048] Example 2 A method for near-zero startup of an alkaline electrolyzer:

[0049] (1) Inject the alkaline electrolyte in the lye tank into the electrolysis cells through the total liquid inlet pipeline, so that the electrolyte is evenly distributed among several electrolysis cells;

[0050] (2) Set the temperatures of the small heating devices of the electrolyzer from top to bottom to 25°C, 45°C, 65°C, 85°C, and 95°C in sequence, start the small heating devices, and heat the electrolysis cells, so that the alkaline electrolyzer module can quickly reach the electrolysis temperature during startup and achieve near-zero startup.

[0051] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification.

[0052] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A multi-pipeline flow diversion device for near-zero start-up of an alkaline electrolytic cell, characterized in that: An alkaline electrolyser module is included; The alkaline electrolytic cell module is composed of a number of regularly arranged electrolytic chambers connected in parallel, and a small heating device is provided between any two adjacent electrolytic chambers; The electrolysis chambers are each provided with a cathode liquid inlet and an anode liquid inlet, a plurality of the cathode liquid inlets are connected in parallel through a cathode liquid inlet main pipeline, and a plurality of the anode liquid inlets are connected in parallel through an anode liquid inlet main pipeline; The electrolysis chambers are each provided with a cathode liquid outlet and an anode liquid outlet, a plurality of the cathode liquid outlets are connected in parallel through a cathode liquid outlet main pipeline, and a plurality of the anode liquid outlets are connected in parallel through an anode liquid outlet main pipeline.

2. A multi-pipeline flow diversion device for near-zero startup of an alkaline electrolytic cell according to claim 1, characterized in that: The cathode liquid inlet main pipeline is connected to the cathode alkali liquid tank, and the anode liquid inlet main pipeline is connected to the anode alkali liquid tank.

3. A multi-pipeline flow diversion device for near-zero startup of an alkaline electrolytic cell according to claim 1, characterized in that: Also included is a gas-liquid separator device, the gas-liquid separator device comprising a cathode gas-liquid separator device and an anode gas-liquid separator device; The cathode liquid outlet main pipeline is connected to the cathode gas-liquid separation device; The anode liquid outlet main pipeline is connected to the anode gas-liquid separation device.

4. A multi-pipeline flow diversion device for near-zero startup of an alkaline electrolytic cell according to claim 3, characterized in that: The cathode gas-liquid separation device is provided with a cathode gas outlet and a cathode liquid outlet, wherein the cathode gas outlet is located above the cathode liquid outlet; The anode gas-liquid separation device is provided with an anode gas outlet and an anode liquid outlet, and the anode gas outlet is located above the anode liquid outlet.

5. A method for near-zero startup of an alkaline electrolytic cell, characterized in that: The device according to any one of claims 1 to 4 comprises the following steps: (1) injecting alkaline electrolyte in the alkali liquid tank into the electrolysis chamber through the main liquid inlet pipeline so that the electrolyte is evenly distributed among the plurality of electrolysis chambers; (2) Start the small heating device to heat the electrolysis chamber so that the alkaline electrolytic cell module can quickly reach the electrolysis temperature during startup and achieve near-zero startup.

6. A method for near-zero startup of an alkaline electrolytic cell according to claim 5, characterized in that: The heating temperature of the small heating device is 25-95°C.

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