Alkaline water electrolysis hydrogen production system and use method thereof

Abstract

The invention discloses an alkaline water electrolysis hydrogen production system, and belongs to the technical field of water electrolysis hydrogen production. For the alkaline water electrolysis hydrogen production system provided with a plurality of electrolytic cells, when the system is in a heating stage, the alkali liquor heater is used for quickly heating the alkali liquor entering the single electrolytic cell, so that the quick cold start of the system can be realized, the start time of the system is greatly shortened, and the energy consumption is reduced. The purposes of greatly improving the operation efficiency, saving energy and reducing consumption under the condition of low energy consumption are achieved. Besides, when the system is in a heat exchange stage, the heating of the rest low-temperature alkali liquor led out from the liquid storage tank is controlled by the heat of the hot alkali liquor of the operated electrolytic bath, so that the requirement of rapid temperature rise of the alkaline water electrolysis hydrogen production system of the plurality of electrolytic baths is met, and the comprehensive energy conservation and consumption reduction of the system are realized.

Description

Technical Field

[0001] The present application relates to the technical field of hydrogen production by water electrolysis, and in particular to an alkaline water electrolysis hydrogen production system and a method for using the same. Background Art

[0002] Hydrogen energy is a clean, carbon-free energy with high energy density. It has the properties of energy carrier, energy storage carrier, and chemical raw material. It can help large-scale consumption of renewable energy, realize large-scale peak load regulation of power grids and cross-seasonal and cross-regional energy storage, and accelerate the low-carbonization of industries, construction, transportation, etc. It is an important carrier for building the country's future energy system and supporting the green and low-carbon transformation of energy-consuming terminals. It is crucial to dominate the international energy market, ensure national energy security, and promote high-quality economic development. It has a high strategic position. Hydrogen production by alkaline water electrolysis is currently an important production method.

[0003] However, there is an urgent need for an alkaline water electrolysis hydrogen production system with faster startup and lower energy consumption. Summary of the invention

[0004] The embodiment of the present application provides an alkaline water electrolysis hydrogen production system and a method for using the same. The present invention can solve the problem in the prior art that an alkaline water electrolysis hydrogen production system with fast startup and low energy consumption is urgently needed. The technical solution is as follows:

[0005] In one aspect, a system for producing hydrogen by electrolyzing alkaline water is provided, the system comprising:

[0006] A liquid storage tank, a lye circulation pump, a lye heater, a stop valve assembly, a gas-liquid separation system, a lye heat exchanger, a heat exchange circulation pump, a lye heat exchange buffer tank and at least two electrolytic cells;

[0007] When the system is in the preparation stage, the stop valve assembly is used to control the first passage consisting of the liquid storage tank, the alkali liquid circulation pump, the alkali liquid heater, one of the electrolytic cells and the gas-liquid separation system in sequence to be turned on; after the liquid level in the gas-liquid separation system reaches a first target liquid level value, the stop valve assembly is used to control the passage between the liquid storage tank and the alkali liquid circulation pump to be closed, and at the same time control the second passage consisting of the gas-liquid separation system, the alkali liquid heat exchanger, the alkali liquid circulation pump, the alkali liquid heater and one of the electrolytic cells in sequence to be turned on;

[0008] When the system is in the heating stage, the alkali solution heater is used to heat the alkali solution entering one of the electrolytic cells to a first temperature threshold and then shut down, while one of the electrolytic cells is turned on and is in a normal hydrogen production and heat release state so that the temperature of the alkali solution output by one of the electrolytic cells reaches a second temperature threshold;

[0009] When the system is in the heat exchange stage, the stop valve assembly is used to control the conduction of the third passage composed of the liquid storage tank, the heat exchange circulation pump, the alkali liquid heat exchanger, and the alkali liquid heat exchange buffer tank in sequence, and the alkali liquid heat exchanger is used to exchange heat between the alkali liquid at the second temperature threshold and the alkali liquid flowing out of the liquid storage tank; after the liquid level in the alkali liquid heat exchange buffer tank reaches the second target liquid level value, the stop valve assembly is used to control the closing of the passage between the liquid storage tank and the heat exchange circulation pump and the conduction of the passage between the alkali liquid heat exchange buffer tank and the heat exchange circulation pump, and after the temperature of the alkali liquid in the alkali liquid heat exchange buffer tank reaches the first temperature threshold, the heat exchange circulation pump is controlled to be closed, and the passage between the alkali liquid heat exchanger and the alkali liquid heat exchange buffer tank is closed, and the fourth passage composed of the alkali liquid heat exchange buffer tank, the alkali liquid circulation pump, another electrolyzer and the gas-liquid separation system in sequence is controlled to be conducted, and at the same time, the other electrolyzer is opened and is in a normal hydrogen production and heat release state.

[0010] Optionally, when the second target liquid level value of the alkali liquid in the alkali liquid heat exchange buffer tank is close to the zero liquid level, the stop valve assembly is used to control the closing of the passage between the alkali liquid heat exchange buffer tank and the alkali liquid circulation pump, and at the same time control the connection of the third passage, the alkali liquid heat exchanger is used to exchange heat between the alkali liquid at the second temperature threshold and the alkali liquid flowing out of the liquid storage tank, and after the liquid level in the alkali liquid heat exchange buffer tank reaches the second target liquid level value, the stop valve assembly is used to control the closing of the passage between the liquid storage tank and the heat exchange circulation pump and the connection of the passage between the alkali liquid heat exchange buffer tank and the heat exchange circulation pump, and after the temperature of the alkali liquid in the alkali liquid heat exchange buffer tank reaches the first temperature threshold, the heat exchange circulation pump is controlled to be closed, and the passage between the alkali liquid heat exchanger and the alkali liquid heat exchange buffer tank is closed, and at the same time, the fifth passage consisting of the alkali liquid heat exchange buffer tank, the alkali liquid circulation pump, another electrolyzer and the gas-liquid separation system in sequence is controlled to be connected, and at the same time, another electrolyzer is opened and is in a normal hydrogen production and heat release state.

[0011] Optionally, the alkaline water electrolysis hydrogen production system further includes: an alkaline liquid cooler located between the outlet of the gas-liquid separation system and the inlet of the alkaline liquid heat exchanger;

[0012] Among them, after the temperature of the alkali solution output by the last electrolytic cell of the at least two electrolytic cells reaches the second temperature threshold, the alkali solution cooler is turned on to cool the alkali solution so that the temperature of the alkali solution flowing out of the alkali solution cooler reaches the target temperature threshold.

[0013] Optionally, the alkaline water electrolysis hydrogen production system also includes: a first pipeline connecting the liquid storage tank and the inlet of the heat exchange circulation pump, a second pipeline connecting the outlet of the heat exchange circulation pump and the first inlet of the alkali liquid heat exchanger, a third pipeline connecting the first outlet of the alkali liquid heat exchanger and the inlet of the alkali liquid heat exchange buffer tank, a fourth pipeline connecting the outlet of the alkali liquid heat exchange buffer tank and the first pipeline, at least two fifth pipelines connecting the outlets of the at least two electrolyzers and the inlet of the gas-liquid separation system respectively, a sixth pipeline connecting the outlet of the gas-liquid separation system and the inlet of the alkali liquid cooler, a seventh pipeline connecting the outlet of the alkali liquid cooler and the second inlet of the alkali liquid heat exchanger, an eighth pipeline connecting the second outlet of the alkali liquid heat exchanger and the inlet of the alkali liquid circulation pump, a ninth pipeline connecting the first pipeline and the inlet of the alkali liquid circulation pump, a tenth pipeline and at least two eleventh pipelines,

[0014] Among them, one end of the at least two eleventh pipelines is respectively connected to the inlet of the at least two electrolytic cells, the other end of the at least two eleventh pipelines is connected to one end of the tenth pipeline, and the other end of the tenth pipeline is connected to the outlet of the alkali solution circulation pump.

[0015] Optionally, the stop valve assembly includes: a first stop valve installed on the first pipeline and located between the outlet of the liquid storage tank and the inlet of the ninth pipeline, a second stop valve installed on the third pipeline, a third stop valve installed on the fourth pipeline, a fourth stop valve installed on the fifth pipeline, a fifth stop valve installed on the eighth pipeline, a sixth stop valve installed on the ninth pipeline and located between the inlet of the ninth pipeline and the outlet of the eighth pipeline, and a seventh stop valve installed on the eleventh pipeline.

[0016] Optionally, the stop valve assembly further includes: an eighth stop valve installed between the outlet of the alkali solution circulation pump and the inlet of the liquid storage tank.

[0017] Optionally, when the system is in a shutdown stage, the shut-off valve assembly is also used to close the passage between the alkali solution circulation pump and each of the electrolytic cells, and to open the passage between the alkali solution circulation pump and the liquid storage tank.

[0018] Optionally, the alkaline water electrolysis hydrogen production system also includes: at least two first temperature detection components, at least two second temperature detection components, a third temperature detection component and a fourth temperature detection component, the at least two first temperature detection components are connected one-to-one with the inlets of the at least two electrolytic cells, the at least two second temperature detection components are connected one-to-one with the outlets of the at least two electrolytic cells, the third temperature detection component is connected to the outlet of the alkali liquid cooler, and the fourth temperature detection component is connected to the alkali liquid heat exchange buffer tank.

[0019] Optionally, the alkaline water electrolysis hydrogen production system also includes: a central controller, and the first temperature detection component, the second temperature detection component, the third temperature detection component, the fourth temperature detection component, the stop valve assembly, the alkali solution circulation pump, the heat exchange circulation pump and the alkali solution cooler are all electrically connected to the central controller.

[0020] On the other hand, a method for using an alkaline water electrolysis hydrogen production system is provided, the method comprising:

[0021] The alkaline water electrolysis hydrogen production system is any of the alkaline water electrolysis hydrogen production systems given above, and the method comprises:

[0022] Control the stop valve assembly to conduct a first passage consisting of the liquid storage tank, the alkali liquid circulation pump, the alkali liquid heater, one of the electrolytic cells and the gas-liquid separation system in sequence; after the liquid level in the gas-liquid separation system reaches a first target liquid level value, control the stop valve assembly to close the passage between the liquid storage tank and the alkali liquid circulation pump, and at the same time conduct a second passage consisting of the gas-liquid separation system, the alkali liquid heat exchanger, the alkali liquid circulation pump and one of the electrolytic cells in sequence;

[0023] Control the alkali solution heater to heat the alkali solution entering one of the electrolytic cells to a first temperature threshold, then turn off the alkali solution heater, and simultaneously control one of the electrolytic cells to be powered on to generate hydrogen and release heat so that the temperature of the alkali solution rises to the second temperature threshold;

[0024] The stop valve assembly is controlled to open the third passage which is composed of the liquid storage tank, the heat exchange circulation pump, the alkali liquid heat exchanger and the alkali liquid heat exchange buffer tank in sequence. After the liquid level in the alkali liquid heat exchange buffer tank reaches the second target liquid level value, the stop valve assembly is controlled to close the passage between the liquid storage tank and the heat exchange circulation pump and open the passage between the alkali liquid heat exchange buffer tank and the heat exchange circulation pump. After the temperature of the alkali liquid in the alkali liquid heat exchange buffer tank reaches the first temperature threshold, the heat exchange circulation pump is controlled to be closed, and the passage between the alkali liquid heat exchanger and the alkali liquid heat exchange buffer tank is closed. The fourth passage which is composed of the alkali liquid heat exchange buffer tank, the alkali liquid circulation pump, another electrolyzer and the gas-liquid separation system in sequence is controlled to be opened, and at the same time, the other electrolyzer is controlled to be energized to produce hydrogen and release heat.

[0025] The beneficial effects brought by the technical solution provided by the embodiment of the present application include at least:

[0026] An alkaline water electrolysis hydrogen production system may include: a liquid storage tank, an alkaline solution circulation pump, an alkaline solution heater, a stop valve assembly, a gas-liquid separation system, an alkaline solution heat exchanger, a heat exchange circulation pump, an alkaline solution heat exchange buffer tank, and at least two electrolyzers. For an alkaline water electrolysis hydrogen production system provided with multiple electrolyzers, when the system is in the heating stage, the alkaline solution entering a single electrolyzer is quickly heated by the alkaline solution heater, so that a rapid cold start of the system can be achieved, which greatly reduces the system startup time, and achieves the purpose of greatly improving the operating efficiency and energy saving and consumption reduction at a lower energy consumption. In addition, when the system is in the heat exchange stage, the heat of the hot alkaline solution of the running electrolyzer itself is used to control the heating of the remaining low-temperature alkaline solution derived from the liquid storage tank, so as to meet the requirements of rapid heating of the alkaline water electrolysis hydrogen production system of multiple electrolyzers, and achieve comprehensive energy saving and consumption reduction of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 It is a structural schematic diagram of an alkaline water electrolysis hydrogen production system provided in an embodiment of the present application;

[0029] Figure 2 is a structural schematic diagram of a first path provided in an embodiment of the present application;

[0030] Figure 3 is a structural schematic diagram of a second path provided in an embodiment of the present application;

[0031] Figure 4It is a structural schematic diagram of another alkaline water electrolysis hydrogen production system provided in an embodiment of the present application;

[0032] Figure 5 It is a structural schematic diagram of another alkaline water electrolysis hydrogen production system provided in an embodiment of the present application.

[0033] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0034] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] It should be understood that the references to "one embodiment" or "an embodiment" throughout the specification mean that the specific features, structures, or characteristics associated with the embodiment are included in at least one embodiment of the present invention. Therefore, the references to "in one embodiment" or "in an embodiment" appearing throughout the specification do not necessarily refer to the same embodiment. In addition, these specific features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0037] Please refer to Figure 1 , Figure 1 It is a structural schematic diagram of an alkaline water electrolysis hydrogen production system provided in an embodiment of the present application. The alkaline water electrolysis hydrogen production system 000 may include: a liquid storage tank 100, an alkaline solution circulation pump 200, an alkaline solution heater 300, a stop valve assembly 400, a gas-liquid separation system 500, an alkaline solution heat exchanger 600, a heat exchange circulation pump 700, an alkaline solution heat exchange buffer tank 800 and at least two electrolytic cells 900.

[0038] Please refer to Figure 2 and Figure 3 , Figure 2 is a structural schematic diagram of a first path provided in an embodiment of the present application, Figure 3It is a structural schematic diagram of a second passage provided in an embodiment of the present application. When the alkaline water electrolysis hydrogen production system 000 is in the preparation stage, the stop valve assembly 400 in the alkaline water electrolysis hydrogen production system 000 can be used to control the first passage L1 composed of the liquid storage tank 100, the alkali liquid circulation pump 200, the alkali liquid heater 300, an electrolyzer 900 and the gas-liquid separation system 500 in sequence to be turned on. After the liquid level in the gas-liquid separation system 500 reaches the first target liquid level value, the stop valve assembly 400 can be used to control the passage between the liquid storage tank 100 and the alkali liquid circulation pump 200 to be closed, and at the same time control the gas-liquid separation system 500, the alkali liquid heat exchanger 600, the alkali liquid circulation pump 200, the alkali liquid heater 300 and an electrolyzer 900 in sequence to be turned on.

[0039] Here, controlling the second passage L2 composed of the gas-liquid separation system 500, the alkali liquid heat exchanger 600, the alkali liquid circulation pump 200, the alkali liquid heater 300 and an electrolytic cell 900 in sequence to be turned on can be: ensuring that the alkali liquid can circulate through the electrolytic cell 900 and sequentially pass through the gas-liquid separation system 500, the alkali liquid heat exchanger 600, the alkali liquid circulation pump 200 and the alkali liquid heater 300. For example, the alkali liquid heater 300 can be a pipeline electric heater or an immersion electric heater.

[0040] On the basis of the system completing the preparation stage, when the alkaline water electrolysis hydrogen production system 000 is in the heating stage, the alkali solution heater 300 can be used to heat the alkali solution entering an electrolytic cell 900 to a first temperature threshold and then shut down, and at the same time, the electrolytic cell 900 is powered on to start the hydrogen production exothermic state so that the temperature of the alkali solution output by the electrolytic cell 900 reaches a second temperature threshold. It should be noted that the second temperature threshold is greater than the first temperature threshold. For example, the range of the first temperature threshold can be: 60 degrees to 65 degrees, and the range of the second temperature threshold can be: 85 degrees to 90 degrees.

[0041] On the basis that the system completes the heating stage, when the alkaline water electrolysis hydrogen production system 000 is in the heat exchange stage, the stop valve assembly 400 can be used to control the conduction of the third passage composed of the liquid storage tank 100, the heat exchange circulation pump 700, the alkali solution heat exchanger 600 and the alkali solution buffer tank 800 in sequence. The alkali solution heat exchanger 600 can be used to exchange heat between the alkali solution at the second temperature threshold and the alkali solution introduced into the alkali solution heat exchanger 600 from the liquid storage tank 100. After the alkali solution level in the alkali solution heat exchange buffer tank 800 reaches the second target level value, the stop valve assembly 400 can be used to control the closing of the passage between the liquid storage tank 100 and the heat exchange circulation pump 700 and the conduction of the passage between the alkali solution heat exchange buffer tank 800 and the heat exchange circulation pump 700. After the temperature of the alkali liquid in the alkali liquid heat exchange buffer tank 800 reaches the first temperature threshold, the heat exchange circulation pump 700 is controlled to be closed, and the passage between the alkali liquid heat exchanger 600 and the alkali liquid heat exchange buffer tank 800 is closed, and the fourth passage composed of the alkali liquid heat exchange buffer tank 800, the alkali liquid circulation pump 200, another electrolyzer 900 and the gas-liquid separation system 500 is controlled to be turned on, and at the same time, another electrolyzer 900 is turned on to produce hydrogen and release heat. Here, the alkali liquid in the alkali liquid heat exchange buffer tank 800 can be introduced into another electrolyzer 900 through the alkali liquid circulation pump 200, and after the electrolyzer 900 is powered on to produce hydrogen and release heat, the temperature of the alkali liquid output by this electrolyzer 900 reaches the second temperature threshold.

[0042] For example, the alkali liquid heat exchanger 600 may have two cavities and a heat conducting plate (not shown) for separating the two cavities. The alkali liquid at the second temperature threshold may flow in one cavity, and the alkali liquid derived from the liquid storage tank 100 enters the other cavity, and the two portions of alkali liquid exchange heat in the alkali liquid heat exchanger 600.

[0043] In the embodiment of the present application, for an alkaline water electrolysis hydrogen production system provided with a plurality of electrolytic cells 900, when the system is in the heating stage, the alkaline solution heater 300 quickly heats up the alkaline solution entering a single electrolytic cell 900, so that a rapid cold start of the system can be achieved, which greatly reduces the startup time of the system, and achieves the purpose of greatly improving the operating efficiency and energy saving and consumption reduction at a lower energy consumption. In addition, when the system is in the heat exchange stage, the heat of the hot alkaline solution of the operating electrolytic cell 900 itself controls the heating of the remaining low-temperature alkaline solution derived from the liquid storage tank 100, so as to meet the requirements of rapid heating of the alkaline water electrolysis hydrogen production system of the plurality of electrolytic cells 900, and achieve comprehensive energy saving and consumption reduction of the system.

[0044] In summary, the embodiments of the present application provide an alkaline water electrolysis hydrogen production system, which may include: a liquid storage tank, an alkaline solution circulation pump, an alkaline solution heater, a stop valve assembly, a gas-liquid separation system, an alkaline solution heat exchanger, a heat exchange circulation pump, an alkaline solution heat exchange buffer tank, and at least two electrolyzers. For an alkaline water electrolysis hydrogen production system provided with multiple electrolyzers, when the system is in the heating stage, the alkaline solution entering a single electrolyzer is quickly heated up by the alkaline solution heater, so that a rapid cold start of the system can be achieved, which greatly reduces the startup time of the system, and achieves the purpose of greatly improving the operating efficiency and energy saving and consumption reduction at a lower energy consumption. In addition, when the system is in the heat exchange stage, the heat of the hot alkaline solution of the running electrolyzer itself is used to control the heating of the remaining low-temperature alkaline solution derived from the liquid storage tank, so as to meet the requirements of rapid heating of the alkaline water electrolysis hydrogen production system of multiple electrolyzers, and achieve comprehensive energy saving and consumption reduction of the system.

[0045] For examples, please refer to Figure 4 , Figure 4 Schematic diagram of another alkaline water electrolysis hydrogen production system provided in an embodiment of the present application. The gas-liquid separation system 500 may include: a hydrogen / alkaline liquid separator 501 and an oxygen / alkaline liquid separator 502, and the hydrogen / alkaline liquid separator 501 and the oxygen / alkaline liquid separator 502 may be connected to each electrolytic cell 900. The hydrogen / alkaline liquid separator 501 and the oxygen / alkaline liquid separator 502 can separate gas and liquid.

[0046] Optionally, when the second target liquid level value in the alkali liquid heat exchange buffer tank 800 is close to the zero liquid level, the stop valve assembly 400 can be used to control the passage between the alkali liquid heat exchange buffer tank 800 and the alkali liquid circulation pump 200 to be closed, and at the same time, the third passage can be controlled to be connected (i.e., the third passage composed of the liquid storage tank 100, the heat exchange circulation pump 700, the alkali liquid heat exchanger 600 and the alkali liquid heat exchange buffer tank 800 in sequence). The alkali liquid heat exchanger 600 can be used to exchange heat between the alkali liquid flowing in the alkali liquid heat exchanger 600 at the second temperature threshold and the alkali liquid flowing out of the liquid storage tank 100 to the alkali liquid heat exchanger 600. After the liquid level in the alkali liquid heat exchange buffer tank 800 reaches the second target liquid level value, the stop valve assembly 400 is used to control the passage between the liquid storage tank 100 and the heat exchange circulation pump 700 to be closed and the passage between the alkali liquid heat exchange buffer tank 800 and the heat exchange circulation pump 700 to be connected. After the temperature of the alkali liquid in the alkali liquid heat exchange buffer tank 800 reaches the first temperature threshold, the heat exchange circulation pump 700 is controlled to be closed, and the passage between the alkali liquid heat exchanger 600 and the alkali liquid heat exchange buffer tank 800 is closed, and at the same time, the fifth passage composed of the alkali liquid heat exchange buffer tank 800, the alkali liquid circulation pump 200, another electrolyzer 900 and the gas-liquid separation system 500 is controlled to be turned on, and at the same time, another electrolyzer 900 is turned on to produce hydrogen and release heat. Here, the alkali liquid in the alkali liquid heat exchange buffer tank 800 can be introduced into another electrolyzer 900 through the alkali liquid circulation pump 200, and after the electrolyzer 900 is powered on to produce hydrogen and release heat, the temperature of the alkali liquid output by this electrolyzer reaches the second temperature threshold.

[0047] For example, Figure 4As shown, the operation process of the alkaline water electrolysis hydrogen production system 000 with three electrolytic cells is schematically described as follows: when the system is in the preparation stage, the stop valve assembly 400 can be used to control the first passage composed of the liquid storage tank 100, the alkali liquid circulation pump 200, the alkali liquid heater 300, the first electrolytic cell 900a and the gas-liquid separation system 500 in sequence to be turned on, and at the same time, the alkali liquid circulation pump 200 is running to pass the alkali liquid in the liquid storage tank 100 through the alkali liquid heater 300 (at this time, the alkali liquid heater is not in the working state and is only The first electrolytic cell 900a enters the gas-liquid separation system 500; then, the liquid level in the gas-liquid separation system 500 is observed, and after the alkali liquid level reaches the first target liquid level value, the passage between the liquid storage tank 100 and the alkali liquid circulation pump 200 is closed, and at this time, the second passage composed of the gas-liquid separation system 500, the alkali liquid heat exchanger 600 (at this time, the alkali liquid heat exchanger can only be used as a passage), the alkali liquid circulation pump 200, the alkali liquid heater 300 (at this time, the alkali liquid heater can enter the electric heating state) and the first electrolytic cell 900a is turned on. When the system is in the heating stage, during the circulation of the alkali liquid in the second passage, the alkali liquid heater 300 continuously heats the alkali liquid to raise the temperature, so that the temperature of the alkali liquid entering the first electrolytic cell 900a reaches the first temperature threshold, and then the alkali liquid heater 300 is turned off, and at the same time, the first electrolytic cell 900a is powered on and is in a normal working state, and the alkali liquid in the first electrolytic cell 900a continues to heat up.When the system is in the heat exchange stage, the stop valve assembly 400 connects the third passage consisting of the liquid storage tank 100, the heat exchange circulation pump 700, the alkaline heat exchanger 600, and the alkali solution heat exchange buffer tank 800 in sequence, and the alkali solution heat exchanger 600 is used to exchange heat between the alkali solution at the second temperature threshold and the alkali solution in the liquid storage tank 100 derived by the heat exchange circulation pump 700; after the liquid level in the alkali solution heat exchange buffer tank 800 reaches the second target liquid level value, the stop valve assembly controls the passage between the liquid storage tank 100 and the heat exchange circulation pump 700 to close so that the alkali solution in the liquid storage tank 100 does not flow out, while the passage between the alkali solution heat exchange buffer tank 800 and the heat exchange circulation pump 700 is connected, so that the heat exchange circulation pump 700, the alkali solution heat exchanger 600 and the alkali solution heat exchange buffer tank 800 form a circulation passage; observe the temperature of the alkali solution in the alkali solution heat exchange buffer tank 800, and turn off the heat exchange circulation pump 700 after the temperature reaches the first temperature threshold. , and the passage between the alkali liquid heat exchanger 600 and the alkali liquid heat exchange buffer tank 800 is closed, the fourth passage (the alkali liquid heat exchange buffer tank 800, the alkali liquid circulation pump 200, the second electrolytic cell 900b and the gas-liquid separation system 500 are sequentially composed) is turned on so that the alkali liquid after heat exchange is introduced into the second electrolytic cell 900b and the second electrolytic cell 900b is energized, and the alkali liquid in the second electrolytic cell 900b is heated; when the second target liquid level value of the alkali liquid in the alkali liquid heat exchange buffer tank 800 is close to the zero liquid level, the passage between the alkali liquid heat exchange buffer tank 800 and the alkali liquid circulation pump 200 is controlled to be closed, and the third passage is controlled to be turned on; thereafter, the system continues to run the heat exchange stage, and after the fifth passage (the alkali liquid heat exchange buffer tank 800, the alkali liquid circulation pump 200, the third electrolytic cell 900c and the gas-liquid separation system 500 are sequentially composed) is turned on, the third electrolytic cell 900c is energized, and the alkali liquid in the third electrolytic cell 900c is heated.

[0048] In the embodiments of the present application, Figure 4 As shown, the alkaline water electrolysis hydrogen production system 000 may also include: an alkali liquid cooler 1000 located between the outlet of the gas-liquid separation system 500 and the inlet of the alkali liquid heat exchanger 600. Wherein, after the temperature of the alkali liquid output by the last electrolyzer 900 of at least two electrolyzers 900 reaches the second temperature threshold, the alkali liquid cooler 1000 is turned on to cool down the alkali liquid flowing out of the gas-liquid separation system 500, so that the temperature of the alkali liquid flowing out of the alkali liquid cooler 1000 reaches the target temperature threshold. In this way, the alkali liquid cooler 1000 can take away part of the heat of the alkali liquid flowing out of each electrolyzer 900, so that the temperature of the alkali liquid entering the electrolyzer 900 is the target temperature threshold. For example, the target temperature threshold can be 60 to 65 degrees.

[0049] In the embodiments of the present application, Figure 4As shown, the alkaline water electrolysis hydrogen production system 000 may also include: a first pipeline A1 connecting the liquid storage tank 100 and the inlet of the heat exchange circulation pump 700, a second pipeline A2 connecting the outlet of the heat exchange circulation pump 700 and the first inlet of the alkali liquid heat exchanger 600, a third pipeline A3 connecting the first outlet of the alkali liquid heat exchanger 600 and the inlet of the alkali liquid heat exchange buffer tank 800, a fourth pipeline A4 connecting the outlet of the alkali liquid heat exchange buffer tank 800 and the first pipeline A1, and a fourth pipeline A4 connecting the outlets of at least two electrolyzers 900 and the gas-liquid separation system 900, respectively. At least two fifth pipelines A5 between the inlet of the gas-liquid separation system 500, a sixth pipeline A6 connecting the outlet of the gas-liquid separation system 500 and the inlet of the alkali liquid cooler 1000, a seventh pipeline A7 connecting the outlet of the alkali liquid cooler 1000 and the second inlet of the alkali liquid heat exchanger 600, an eighth pipeline A8 connecting the second outlet of the alkali liquid heat exchanger 600 and the inlet of the alkali liquid circulation pump 200, a ninth pipeline A9 connecting the first pipeline A1 and the inlet of the alkali liquid circulation pump 200, a tenth pipeline A10 and at least two eleventh pipelines A11. It should be noted that the outlet of the eighth pipeline A8 can be connected to the ninth pipeline A9.

[0050] Among them, one end of at least two eleventh A11 pipelines can be connected to the inlets of at least two electrolytic cells 900 respectively, the other end of at least two eleventh A11 pipelines can be connected to one end of the tenth pipeline A10, and the other end of the tenth pipeline A10 can be connected to the outlet of the alkali solution circulation pump 200.

[0051] It should be noted that, when the gas-liquid separation system 500 includes: a hydrogen / alkaline liquid separator 501 and an oxygen / alkaline liquid separator 502, each of the at least two fifth pipelines A5 can include two sub-pipelines, and each electrolyzer 900 is respectively connected to the hydrogen / alkaline liquid separator 501 and the oxygen / alkaline liquid separator 502 through two sub-pipelines.

[0052] Optional, please refer to Figure 4 and Figure 5 , Figure 5It is a structural schematic diagram of another alkaline water electrolysis hydrogen production system provided in an embodiment of the present application. The stop valve assembly 400 in the alkaline water electrolysis hydrogen production system may include: a first stop valve B1 installed on the first pipeline A1 and can be located between the outlet of the liquid storage tank 100 and the inlet of the ninth pipeline A9, a second stop valve B2 installed on the third pipeline A3, a third stop valve B3 installed on the fourth pipeline A4, a fourth stop valve B4 installed on the fifth pipeline A5, a fifth stop valve B5 installed on the eighth pipeline A8, a sixth stop valve B6 installed on the ninth pipeline A9 and located between the inlet of the ninth pipeline A9 and the outlet of the eighth pipeline A8, and a seventh stop valve B7 installed on the eleventh pipeline A11. Here, the number of the fourth stop valve B4 installed on the fifth pipeline A5 can be the same as the number of the fifth pipeline A5 and connected to each other, and the number of the seventh stop valve B7 installed on the eleventh pipeline A11 can be the same as the number of the eleventh pipeline A11 and connected to each other. For example, each stop valve may be a pneumatic stop valve or an electric stop valve.

[0053] In the embodiments of the present application, Figure 5 As shown, the stop valve assembly may further include: an eighth stop valve B8 installed between the outlet of the alkali liquid circulation pump 200 and the inlet of the liquid storage tank 100. For example, the alkaline water electrolysis hydrogen production system further includes: a twelfth pipeline A12 connected between the outlet of the alkali liquid circulation pump 200 and the inlet of the liquid storage tank 100, and the eighth stop valve B8 may be installed on the twelfth pipeline A12.

[0054] Optionally, when the alkaline water electrolysis hydrogen production system is in the shutdown stage, the stop valve assembly 400 can also be used to close the passage between the alkali liquid circulation pump 200 and each electrolyzer 900, and can be used to conduct the passage between the alkali liquid circulation pump 200 and the liquid storage tank 100. For example, each fourth stop valve B4 and each seventh stop valve B7 can be closed, and the eighth stop valve B8 can be opened, and the alkali liquid can be introduced into the liquid storage tank 100 through the alkali liquid circulation pump 200.

[0055] For example, when the alkaline water electrolysis hydrogen production system is in the preparation stage, first, the first stop valve B1 on the first pipeline A1, the sixth stop valve B6 on the ninth pipeline A9, the seventh stop valve B7 on the eleventh pipeline A11 and the fourth stop valve B4 on the fifth pipeline A5 are opened to make the first passage conductive; after the liquid level in the gas-liquid separation system 500 reaches the first target liquid level value, the first stop valve B1 and the sixth stop valve B6 are closed, and the fifth stop valve B5 is opened to make the second passage conductive.

[0056] When the system is in the heating stage, the alkali solution heater 300 is used to heat the alkali solution entering an electrolytic cell 900 to a first temperature threshold and then shut down. At the same time, an electrolytic cell 900 is turned on to produce hydrogen normally and release heat so that the temperature of the alkali solution output by an electrolytic cell 900 reaches a second temperature threshold.

[0057] When the system is in the heat exchange stage, first, the first stop valve B1 on the first pipeline A1 and the second stop valve B2 on the third pipeline A3 are opened to make the third passage conductive. After the liquid level in the alkali solution heat exchange buffer tank 800 reaches the second target liquid level value, the first stop valve B1 on the first pipeline A1 is closed and the third stop valve B3 on the fourth pipeline A4 is opened. After the temperature of the alkali solution in the alkali solution heat exchange buffer tank 800 reaches the first temperature threshold, the heat exchange circulation pump 700 is turned off, and the second stop valve B2 on the third pipeline A3 is closed, and the sixth stop valve B6 on the ninth pipeline A9, the seventh stop valve B7 on another eleventh pipeline A11, and the fourth stop valve B4 on another fifth pipeline A5 are opened to make the fourth passage conductive.

[0058] When the second target liquid level value of the alkali liquid in the alkali liquid heat exchange buffer tank 800 is close to the zero liquid level, the third stop valve B3 on the fourth pipeline A4 and the sixth stop valve B6 on the ninth pipeline A9 are closed, and the first stop valve B1 on the first pipeline A1 and the second stop valve B2 on the third pipeline A3 are opened to make the third passage conductive; after the liquid level in the alkali liquid heat exchange buffer tank reaches the second target liquid level value, the first stop valve B1 on the first pipeline A1 is closed and the third stop valve B3 on the fourth pipeline A4 is opened to make the storage liquid The passage between the tank 100 and the heat exchange circulation pump 700 is closed, and the passage between the alkali liquid heat exchange buffer tank 800 and the heat exchange circulation pump 700 is connected; after the temperature of the alkali liquid in the alkali liquid heat exchange buffer tank 800 reaches the first temperature threshold, the heat exchange circulation pump 700 is turned off, and the second stop valve B2 on the third pipeline A3 is closed, and the sixth stop valve B6 on the ninth pipeline A9 and the seventh stop valve B7 on the eleventh pipeline A11 and the fourth stop valve B4 on the fifth pipeline A5 are opened to make the fifth passage conductive.

[0059] It should be noted that, as the number of opened electrolytic cells 900 increases, the alkali solution circulation flow rate of the alkali solution circulation pump 200 can be gradually increased.

[0060] In the present application embodiment, the alkaline water electrolysis hydrogen production system may also include: at least two first temperature detection components, at least two second temperature detection components, a third temperature detection component and a fourth temperature detection component (not shown). At least two first temperature detection components may be connected to the entrance of at least two electrolyzers in a one-to-one correspondence, at least two second temperature detection components may be connected to the outlet of at least two electrolyzers, the third temperature detection component may be connected to the outlet of the alkali liquid cooler, and the fourth temperature detection component may be connected to the alkali liquid heat exchange buffer tank. In this way, the temperature of the alkali liquid detected by each temperature detection component is to facilitate the control of the flow rate of the alkali liquid circulation pump and the heat exchange circulation pump, the start and stop of the alkali liquid heater, the switch state of the stop valve assembly and the start and stop of the alkali liquid cooler.

[0061] In the present application, the alkaline water electrolysis hydrogen production system may also include: a central controller (not shown in the figure), a first temperature detection component, a second temperature detection component, a third temperature detection component, a fourth temperature detection component, a stop valve assembly, an alkali solution circulation pump, an alkali solution heat exchange circulation pump and an alkali solution cooler may all be electrically connected to the central controller. For example, the first temperature detection component, the second temperature detection component, the third temperature detection component and the fourth temperature detection component may all be temperature sensors. For example, the alkaline water electrolysis hydrogen production system may also include: a first liquid level sensor and a second liquid level sensor (not shown in the figure), the first liquid level sensor may be installed in the gas-liquid separation system and may be electrically connected to the central controller, and the second liquid level sensor may be installed in the alkali solution heat exchange buffer tank and may be electrically connected to the central controller.

[0062] For example, when the system is in the preparation stage, after the first liquid level sensor detects that the liquid level in the gas-liquid separation system 500 reaches the first target liquid level value, the first liquid level signal is sent to the central controller, and the central controller can control the first stop valve B1 and the sixth stop valve B6 to close according to the received first liquid level signal, and control the fifth stop valve B5 to open so that the second passage is conductive. When the system is in the heating stage, after the first temperature detection component detects that the temperature of the alkali liquid entering an electrolytic cell 900 reaches the first temperature threshold, the first temperature signal is sent to the central controller, and the central controller can control the alkali liquid heater 300 (here, the alkali liquid heater can also be manually turned on or off) to close according to the first temperature signal and control the electrolytic cell 900 to be powered on and started.

[0063] When the system is in the heat exchange stage, while the central controller controls the alkali liquid heater 300 to be closed according to the first temperature signal, the first stop valve B1 on the first pipeline A1 and the second stop valve B2 on the third pipeline A3 can be controlled to be opened; after the second liquid level sensor detects that the liquid level in the alkali liquid heat exchange buffer tank 800 reaches the second target liquid level value, the second liquid level signal is sent to the central controller, and the central controller closes the first stop valve B1 on the first pipeline A1 and opens the third stop valve B3 on the fourth pipeline A4 according to the received second liquid level signal; after the fourth temperature detection component detects that the temperature of the alkali liquid in the alkali liquid heat exchange buffer tank 800 reaches the first temperature threshold, the second temperature signal is sent to the central controller, and the central controller controls the heat exchange circulation pump 700 to be closed according to the second temperature signal, and controls the second stop valve B2 on the third pipeline A3 to be closed, and controls the sixth stop valve B6 on the ninth pipeline A9, the seventh stop valve B7 on another eleventh pipeline A11 and the fourth stop valve B4 on another fifth pipeline A5 to be opened to make the fourth passage conductive.

[0064] When the second liquid level sensor detects that the second target liquid level value of the alkali liquid in the alkali liquid heat exchange buffer tank 800 is close to the zero liquid level, it sends a third liquid level signal to the central controller, and the central controller closes the third stop valve B3 on the fourth pipeline A4 and the sixth stop valve B6 on the ninth pipeline A9 according to the received third liquid level signal, and opens the first stop valve B1 on the first pipeline A1 and the second stop valve B2 on the third pipeline A3 to make the third passage conductive; after the second liquid level sensor detects that the liquid level in the alkali liquid heat exchange buffer tank reaches the second target liquid level value, it sends a fourth liquid level signal to the central controller, closes the first stop valve B1 on the first pipeline A1 and opens the fourth pipeline A4. The third stop valve B3 on the alkali liquid heat exchange circulation pump 700 is closed to close the passage between the liquid storage tank 100 and the heat exchange circulation pump 700 and to open the passage between the alkali liquid heat exchange buffer tank 800 and the heat exchange circulation pump 700; after the fourth temperature detection component detects that the temperature of the alkali liquid in the alkali liquid heat exchange buffer tank reaches the first temperature threshold, the third temperature signal is sent to the central controller, and the central controller turns off the heat exchange circulation pump 700 according to the third temperature signal, and closes the second stop valve B2 on the third pipeline A3, and opens the sixth stop valve B6 on the ninth pipeline A9, the seventh stop valve B7 on the eleventh pipeline A11 and the fourth stop valve B4 on the fifth pipeline A5 to make the fifth passage open.

[0065] After the second temperature detection component detects that the temperature of the alkali solution output by the last electrolytic cell 900 reaches the second temperature threshold, a fourth temperature signal is sent to the central controller, and the central controller controls the alkali solution cooler 1000 to start according to the fourth temperature signal. And the temperature of the alkali solution at the outlet of the alkali solution cooler 1000 is detected according to the third temperature detection component to adjust the working power of the alkali solution cooler 1000 through the central controller. It should be noted that the alkali solution cooler 1000 can also be manually turned on or off.

[0066] In summary, the embodiments of the present application provide an alkaline water electrolysis hydrogen production system, which may include: a liquid storage tank, an alkaline solution circulation pump, an alkaline solution heater, a stop valve assembly, a gas-liquid separation system, an alkaline solution heat exchanger, a heat exchange circulation pump, an alkaline solution heat exchange buffer tank, and at least two electrolyzers. For an alkaline water electrolysis hydrogen production system provided with multiple electrolyzers, when the system is in the heating stage, the alkaline solution entering a single electrolyzer is quickly heated up by the alkaline solution heater, so that a rapid cold start of the system can be achieved, which greatly reduces the startup time of the system, and achieves the purpose of greatly improving the operating efficiency and energy saving and consumption reduction at a lower energy consumption. In addition, when the system is in the heat exchange stage, the heat of the hot alkaline solution of the running electrolyzer itself is used to control the heating of the remaining low-temperature alkaline solution derived from the liquid storage tank, so as to meet the requirements of rapid heating of the alkaline water electrolysis hydrogen production system of multiple electrolyzers, and achieve comprehensive energy saving and consumption reduction of the system.

[0067] The application embodiment also provides a method for using an alkaline water electrolysis hydrogen production system, and the alkaline water electrolysis hydrogen production system can be the alkaline water electrolysis hydrogen production system given above. The method for using the alkaline water electrolysis hydrogen production system can include:

[0068] Step 101, control the stop valve assembly to open the first passage consisting of a liquid storage tank, an alkali liquid circulation pump, an alkali liquid heater, an electrolytic cell and a gas-liquid separation system in sequence; after the liquid level in the gas-liquid separation system reaches a first target liquid level value, control the stop valve assembly to close the passage between the liquid storage tank and the alkali liquid circulation pump, and at the same time open the second passage consisting of the gas-liquid separation system, an alkali liquid heat exchanger, an alkali liquid circulation pump and an electrolytic cell in sequence.

[0069] Step 102: Control the alkali solution heater to heat the alkali solution entering an electrolytic cell to a first temperature threshold and then turn off the alkali solution heater; at the same time, control an electrolytic cell to be powered on to produce hydrogen and release heat to raise the temperature of the alkali solution to a second temperature threshold.

[0070] Step 103, control the stop valve assembly to open the third passage composed of the liquid storage tank, the heat exchange circulation pump, the alkali liquid heat exchanger and the alkali liquid heat exchange buffer tank in sequence; after the liquid level in the alkali liquid heat exchange buffer tank reaches the second target liquid level value, control the stop valve assembly to close the passage between the liquid storage tank and the heat exchange circulation pump and open the passage between the alkali liquid heat exchange buffer tank and the heat exchange circulation pump.

[0071] Step 104, after the temperature of the alkali liquid in the alkali liquid heat exchange buffer tank reaches the first temperature threshold, the heat exchange circulation pump is controlled to be closed, and the passage between the alkali liquid heat exchanger and the alkali liquid heat exchange buffer tank is closed, and the fourth passage consisting of the alkali liquid heat exchange buffer tank, the alkali liquid circulation pump, another electrolytic cell and the gas-liquid separation system in sequence is controlled to be turned on, and at the same time, another electrolytic cell is controlled to be powered on to produce hydrogen and release heat to increase the temperature of the alkali liquid therein.

[0072] In summary, the embodiments of the present application provide a method for using an alkaline water electrolysis hydrogen production system. For an alkaline water electrolysis hydrogen production system provided with multiple electrolytic cells, when the system is in the heating stage, the alkaline solution entering a single electrolytic cell is quickly heated by an alkaline solution heater, so that a rapid cold start of the system can be achieved, which greatly reduces the startup time of the system, and achieves the purpose of greatly improving the operating efficiency and energy saving and consumption reduction at a lower energy consumption. In addition, when the system is in the heat exchange stage, the heat of the hot alkaline solution of the operating electrolytic cell itself is used to control the heating of the remaining low-temperature alkaline solution derived from the liquid storage tank, so as to meet the requirements of rapid heating of the alkaline water electrolysis hydrogen production system of multiple electrolytic cells, and achieve comprehensive energy saving and consumption reduction of the system.

[0073] It should be noted that the sequence of steps in the method for using the alkaline water electrolysis hydrogen production system provided in the embodiment of the present invention can be appropriately adjusted, and the steps can be increased or decreased accordingly according to the circumstances. Any technician familiar with the technical field can easily think of the changes within the technical scope disclosed by the present invention, and they should be covered within the scope of protection of the present invention, so they will not be repeated here.

[0074] The embodiments of the alkaline water electrolysis hydrogen production system and the embodiments of the method for using the alkaline water electrolysis hydrogen production system provided in the embodiments of the present invention can be referenced to each other, and the embodiments of the present invention will not be described in detail here.

[0075] In the present application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. The term "plurality" refers to two or more than two, unless otherwise clearly defined.

[0076] The above description is only an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. An alkaline water electrolysis hydrogen production system, characterized in that: include: A liquid storage tank, a lye circulation pump, a lye heater, a stop valve assembly, a gas-liquid separation system, a lye heat exchanger, a heat exchange circulation pump, a lye heat exchange buffer tank and at least two electrolytic cells; When the system is in the preparation stage, the stop valve assembly is used to control the first passage consisting of the liquid storage tank, the alkali liquid circulation pump, the alkali liquid heater, one of the electrolytic cells and the gas-liquid separation system in sequence to be turned on; after the liquid level in the gas-liquid separation system reaches a first target liquid level value, the stop valve assembly is used to control the passage between the liquid storage tank and the alkali liquid circulation pump to be closed, and at the same time control the second passage consisting of the gas-liquid separation system, the alkali liquid heat exchanger, the alkali liquid circulation pump, the alkali liquid heater and one of the electrolytic cells in sequence to be turned on; When the system is in the heating stage, the alkali solution heater is used to heat the alkali solution entering one of the electrolytic cells to a first temperature threshold and then shut down, while one of the electrolytic cells is turned on and is in a normal hydrogen production and heat release state so that the temperature of the alkali solution output by one of the electrolytic cells reaches a second temperature threshold; When the system is in the heat exchange stage, the stop valve assembly is used to control the conduction of the third passage composed of the liquid storage tank, the heat exchange circulation pump, the alkali liquid heat exchanger, and the alkali liquid heat exchange buffer tank in sequence, and the alkali liquid heat exchanger is used to exchange heat between the alkali liquid at the second temperature threshold and the alkali liquid flowing out of the liquid storage tank; after the liquid level in the alkali liquid heat exchange buffer tank reaches the second target liquid level value, the stop valve assembly is used to control the closing of the passage between the liquid storage tank and the heat exchange circulation pump and the conduction of the passage between the alkali liquid heat exchange buffer tank and the heat exchange circulation pump, and after the temperature of the alkali liquid in the alkali liquid heat exchange buffer tank reaches the first temperature threshold, the heat exchange circulation pump is controlled to be closed, and the passage between the alkali liquid heat exchanger and the alkali liquid heat exchange buffer tank is closed, and the fourth passage composed of the alkali liquid heat exchange buffer tank, the alkali liquid circulation pump, another electrolyzer and the gas-liquid separation system in sequence is controlled to be conducted, and at the same time, the other electrolyzer is opened and is in a normal hydrogen production and heat release state.

2. The alkaline water electrolysis hydrogen production system according to claim 1, characterized in that: When the second target liquid level value of the alkali liquid in the alkali liquid heat exchange buffer tank is close to the zero liquid level, the stop valve assembly is used to control the closure of the passage between the alkali liquid heat exchange buffer tank and the alkali liquid circulation pump, and at the same time control the connection of the third passage. The alkali liquid heat exchanger is used to exchange heat between the alkali liquid at the second temperature threshold and the alkali liquid flowing out of the liquid storage tank. After the liquid level in the alkali liquid heat exchange buffer tank reaches the second target liquid level value, the stop valve assembly is used to control the closure of the passage between the liquid storage tank and the heat exchange circulation pump and the connection of the passage between the alkali liquid heat exchange buffer tank and the heat exchange circulation pump. After the temperature of the alkali liquid in the alkali liquid heat exchange buffer tank reaches the first temperature threshold, the heat exchange circulation pump is controlled to be closed, and the passage between the alkali liquid heat exchanger and the alkali liquid heat exchange buffer tank is closed. At the same time, the fifth passage consisting of the alkali liquid heat exchange buffer tank, the alkali liquid circulation pump, another electrolyzer and the gas-liquid separation system is controlled to be connected, and at the same time, another electrolyzer is opened and is in a normal hydrogen production and heat release state.

3. The alkaline water electrolysis hydrogen production system according to claim 2, characterized in that: The alkaline water electrolysis hydrogen production system further includes: an alkaline liquid cooler located between the outlet of the gas-liquid separation system and the inlet of the alkaline liquid heat exchanger; Among them, after the temperature of the alkali solution output by the last electrolytic cell of the at least two electrolytic cells reaches the second temperature threshold, the alkali solution cooler is turned on to cool the alkali solution so that the temperature of the alkali solution flowing out of the alkali solution cooler reaches the target temperature threshold.

4. The alkaline water electrolysis hydrogen production system according to claim 3, characterized in that: The alkaline water electrolysis hydrogen production system also includes: a first pipeline connecting the liquid storage tank and the inlet of the heat exchange circulation pump, a second pipeline connecting the outlet of the heat exchange circulation pump and the first inlet of the alkali liquid heat exchanger, a third pipeline connecting the first outlet of the alkali liquid heat exchanger and the inlet of the alkali liquid heat exchange buffer tank, a fourth pipeline connecting the outlet of the alkali liquid heat exchange buffer tank and the first pipeline, at least two fifth pipelines connecting the outlets of the at least two electrolyzers and the inlet of the gas-liquid separation system respectively, a sixth pipeline connecting the outlet of the gas-liquid separation system and the inlet of the alkali liquid cooler, a seventh pipeline connecting the outlet of the alkali liquid cooler and the second inlet of the alkali liquid heat exchanger, an eighth pipeline connecting the second outlet of the alkali liquid heat exchanger and the inlet of the alkali liquid circulation pump, a ninth pipeline connecting the first pipeline and the inlet of the alkali liquid circulation pump, a tenth pipeline and at least two eleventh pipelines, Among them, one end of the at least two eleventh pipelines is respectively connected to the inlet of the at least two electrolytic cells, the other end of the at least two eleventh pipelines is connected to one end of the tenth pipeline, and the other end of the tenth pipeline is connected to the outlet of the alkali solution circulation pump.

5. The alkaline water electrolysis hydrogen production system according to claim 4, characterized in that: The stop valve assembly includes: a first stop valve installed on the first pipeline and located between the outlet of the liquid storage tank and the inlet of the ninth pipeline, a second stop valve installed on the third pipeline, a third stop valve installed on the fourth pipeline, a fourth stop valve installed on the fifth pipeline, a fifth stop valve installed on the eighth pipeline, a sixth stop valve installed on the ninth pipeline and located between the inlet of the ninth pipeline and the outlet of the eighth pipeline, and a seventh stop valve installed on the eleventh pipeline.

6. The alkaline water electrolysis hydrogen production system according to claim 5, characterized in that: The stop valve assembly further includes: an eighth stop valve installed between the outlet of the alkali solution circulation pump and the inlet of the liquid storage tank.

7. The alkaline water electrolysis hydrogen production system according to claim 1, characterized in that: When the system is in the shutdown stage, the stop valve assembly is also used to close the passage between the alkali solution circulation pump and each of the electrolytic cells, and to open the passage between the alkali solution circulation pump and the liquid storage tank.

8. The alkaline water electrolysis hydrogen production system according to any one of claims 1 to 7, characterized in that: The alkaline water electrolysis hydrogen production system also includes: at least two first temperature detection components, at least two second temperature detection components, a third temperature detection component and a fourth temperature detection component, the at least two first temperature detection components are connected to the inlets of the at least two electrolytic cells in a one-to-one correspondence, the at least two second temperature detection components are connected to the outlets of the at least two electrolytic cells in a one-to-one correspondence, the third temperature detection component is connected to the outlet of the alkali liquid cooler, and the fourth temperature detection component is connected to the alkali liquid heat exchange buffer tank.

9. The alkaline water electrolysis hydrogen production system according to claim 8, characterized in that: The alkaline water electrolysis hydrogen production system also includes: a central controller, and the first temperature detection component, the second temperature detection component, the third temperature detection component, the fourth temperature detection component, the stop valve assembly, the alkali solution circulation pump, the heat exchange circulation pump and the alkali solution cooler are all electrically connected to the central controller.

10. A method for using an alkaline water electrolysis hydrogen production system, characterized in that: The alkaline water electrolysis hydrogen production system is the alkaline water electrolysis hydrogen production system according to any one of claims 1 to 9 above, and the method comprises: Control the stop valve assembly to conduct a first passage consisting of the liquid storage tank, the alkali liquid circulation pump, the alkali liquid heater, one of the electrolytic cells and the gas-liquid separation system in sequence; after the liquid level in the gas-liquid separation system reaches a first target liquid level value, control the stop valve assembly to close the passage between the liquid storage tank and the alkali liquid circulation pump, and at the same time conduct a second passage consisting of the gas-liquid separation system, the alkali liquid heat exchanger, the alkali liquid circulation pump and one of the electrolytic cells in sequence; Control the alkali solution heater to heat the alkali solution entering one of the electrolytic cells to a first temperature threshold, then turn off the alkali solution heater, and simultaneously control one of the electrolytic cells to be powered on to generate hydrogen and release heat so that the temperature of the alkali solution rises to the second temperature threshold; The stop valve assembly is controlled to open the third passage which is composed of the liquid storage tank, the heat exchange circulation pump, the alkali liquid heat exchanger and the alkali liquid heat exchange buffer tank in sequence. After the liquid level in the alkali liquid heat exchange buffer tank reaches the second target liquid level value, the stop valve assembly is controlled to close the passage between the liquid storage tank and the heat exchange circulation pump and open the passage between the alkali liquid heat exchange buffer tank and the heat exchange circulation pump. After the temperature of the alkali liquid in the alkali liquid heat exchange buffer tank reaches the first temperature threshold, the heat exchange circulation pump is controlled to be closed, and the passage between the alkali liquid heat exchanger and the alkali liquid heat exchange buffer tank is closed. The fourth passage which is composed of the alkali liquid heat exchange buffer tank, the alkali liquid circulation pump, another electrolyzer and the gas-liquid separation system in sequence is controlled to be opened, and at the same time, the other electrolyzer is controlled to be energized to produce hydrogen and release heat.

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