Efficient hydrogen production system and method for immersed alkaline electrolytic cell

Abstract

The invention provides an efficient hydrogen production system and method for an immersed alkaline electrolytic cell, and relates to the field of alkaline electrolytic hydrogen production, the system comprises an alkaline electrolytic cell, an immersion tank, an alkali liquor storage tank and a heat exchanger assembly with a cold source or a heat source, the immersion tank is filled with a liquid-phase insulating working medium, and the alkaline electrolytic cell is located in the immersion tank; the insulating layer is completely immersed in the insulating working medium; an alkali liquor outlet of the alkali liquor storage tank is communicated with an alkali liquor inlet of the alkaline electrolytic bath, a temperature adjusting coil pipe, a heat exchanger assembly, the immersion tank and the temperature adjusting coil pipe are sequentially communicated in the flowing direction of the insulating working medium, and the heat exchanger assembly is used for cooling or heating the insulating working medium; and the insulating working medium flowing through the temperature adjusting coil pipe can exchange heat with alkali liquor in the alkali liquor storage tank. According to the system and the method, the alkali liquor heating temperature control and the in-situ heating temperature control of the alkaline electrolytic bath can be realized at the same time, and the system variable load response speed of the alkaline electrolytic hydrogen production system under the working conditions of preheating, hot standby, relatively low operating temperature and the like is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of alkaline electrolysis hydrogen production, and in particular to an immersion-type alkaline electrolytic cell high-efficiency hydrogen production system and method. Background Art

[0002] Driven by the goals of energy transformation and carbon neutrality, alkaline electrolysis has become an important technical path for hydrogen production due to its mature technology and controllable costs. This technology uses renewable energy electricity to electrolyze water to produce hydrogen, which is in line with the development trend of clean energy and low carbonization, and plays a key role in the green upgrade of many industries such as chemical and metallurgy. However, the thermal response characteristics of alkaline electrolyzers are poor, which seriously restricts the efficiency and stability of the system's variable load operation. During operation, alkaline electrolyzers need to maintain a suitable temperature to ensure the efficient electrolysis reaction, but the large thermal inertia of the cell makes it difficult to respond quickly to load changes.

[0003] In the prior art, when the temperature of an alkaline electrolytic cell is controlled, alkaline electrolyte is drawn out of the electrolytic cell to perform heat exchange with a heat exchange medium.

[0004] The applicant has discovered that the prior art suffers from at least the following technical problems: When alkaline electrolyzers operate at variable loads, their thermal response lags behind load changes, leading to temperature imbalance and severely impacting hydrogen production efficiency and equipment stability. When the load decreases, the electrochemical reaction rate slows, and heat generation correspondingly decreases. However, due to the electrolyzer's large heat capacity and slow cooling system response, heat dissipation decreases more slowly than heat generation, resulting in a temporary accumulation of heat within the cell and a temperature increase. Excessive temperatures disrupt the electrolysis reaction equilibrium, reducing the efficiency and purity of hydrogen and oxygen production, and may even cause electrolyte concentration and crystallization, leading to pipeline blockage. When the load increases, the reaction rate accelerates, significantly increasing ohmic heat and irreversible heat of electrochemical reaction. However, the cooling system is unable to increase heat dissipation capacity in a timely manner. This substantial heat accumulation causes the cell temperature to rapidly exceed the optimal operating temperature, accelerating electrode corrosion, reducing diaphragm durability, and leading to increased electrolyte evaporation and concentration fluctuations, further degrading electrolysis efficiency. Furthermore, frequent load fluctuations lead to frequent cell temperature fluctuations, which not only exacerbate electrode thermal fatigue and cause coating flaking, but also cause unstable gas volume expansion coefficients, complicating gas-liquid separation. These thermal response issues seriously restrict the compatibility of alkaline electrolyzers with renewable energy and hinder their large-scale application.

[0005] In summary, the temperature imbalance problem caused by poor thermal response characteristics in alkaline electrolysis hydrogen production systems seriously affects hydrogen production efficiency, hydrogen quality, equipment life and energy utilization efficiency, and has become a key bottleneck restricting the coordinated development of alkaline electrolysis hydrogen production technology and renewable energy and the realization of large-scale application. Summary of the Invention

[0006] The present invention aims to provide a highly efficient hydrogen production system and method using an immersed alkaline electrolyzer. This system addresses the technical issues inherent in prior art methods, such as the inability to control the electrolyzer temperature by extracting the electrolyte from the electrolyzer for heat exchange, resulting in poor thermal response characteristics and temperature imbalance in the hydrogen production system. The various technical effects achieved by the preferred technical solutions provided by the present invention are detailed below.

[0007] To achieve the above objectives, the present invention provides the following technical solutions:

[0008] The present invention provides an immersion-type alkaline electrolyzer high-efficiency hydrogen production system, comprising an alkaline electrolyzer, an immersion tank, an alkaline solution storage tank, and a heat exchanger assembly with a cold source or a heat source, wherein:

[0009] The immersion tank is filled with a liquid insulating medium, and the alkaline electrolytic cell is located in the immersion tank and is completely immersed in the insulating medium;

[0010] The alkali liquid outlet of the alkali liquid storage tank is connected to the alkali liquid inlet of the alkaline electrolytic cell. A temperature regulating coil is provided in the alkali liquid storage tank. The heat exchanger assembly, the immersion tank, and the temperature regulating coil are sequentially connected along the flow direction of the insulating working medium. The heat exchanger assembly is used to cool or heat the insulating working medium. The insulating working medium flowing through the temperature regulating coil can exchange heat with the alkali liquid in the alkali liquid storage tank.

[0011] Preferably, the heat exchanger assembly includes a cold source heat exchanger, wherein:

[0012] A first cold coil is provided in the cold source heat exchanger, wherein the cold source outlet of the first cold coil is connected to the immersion tank via a cold source liquid inlet pipe, and can be in a connected or blocked state; the cold source inlet of the cold source heat exchanger is connected to the temperature regulating coil via a cold source liquid outlet pipe, and can be in a connected or blocked state;

[0013] When the first cooling coil, the immersion tank and the temperature regulating coil are all connected, a first cooling circuit can be formed.

[0014] Preferably, the heat exchanger assembly includes a heat source heat exchanger, wherein the heat source heat exchanger has a heat extraction coil, the heat source outlet of the heat extraction coil is connected to the immersion tank via a heat source liquid inlet pipe, and has a connected or blocked state, and the heat source inlet of the heat source heat exchanger is connected to the temperature regulating coil via a heat source liquid outlet pipe, and has a connected or blocked state;

[0015] The heat extraction coil, the immersion tank and the temperature regulating coil are all connected to form a heating circuit.

[0016] Preferably, a cooling circuit pump and a cooling circuit liquid supply valve are provided on the outlet pipe section of the first cooling coil, and a first liquid return valve is provided on the inlet pipe section of the first cooling coil. When the cooling circuit pump, the cooling circuit liquid supply valve and the first liquid return valve are all opened, the first cooling coil, the immersion tank and the temperature regulating coil are connected;

[0017] The first cooling circuit is connected to a first expansion tank, and the first expansion tank is located between the first cooling coil and the immersion tank.

[0018] Preferably, a heating circuit pump and a heating circuit liquid supply valve are provided on the outlet pipe section of the heat extraction coil, and a second liquid return valve is provided on the inlet pipe section of the heat extraction coil. When the heating circuit pump, the heating circuit liquid supply valve and the second liquid return valve are all opened, the heat extraction coil, the immersion tank and the temperature control coil are connected.

[0019] Preferably, the submerged alkaline electrolyzer efficient hydrogen production system further includes a hydrogen separator and an oxygen separator, wherein:

[0020] The hydrogen separator is connected to the hydrogen outlet of the alkaline electrolyzer, and the oxygen separator is connected to the oxygen outlet of the alkaline electrolyzer; a hydrogen cooling coil is provided in the hydrogen separator, an oxygen cooling coil is provided in the oxygen separator, and a second cooling coil is provided in the cold source heat exchanger. The second cooling coil, the hydrogen cooling coil, and the oxygen cooling coil are connected in sequence to form a second cooling circuit;

[0021] The second cooling circuit is provided with a separator cooling circulation pump and a second expansion tank.

[0022] Preferably, a first droplet catcher is provided in the hydrogen separator, a second droplet catcher is provided in the oxygen separator, the hydrogen separator and the oxygen separator are both connected to the alkali liquid storage tank through an alkali liquid reflux pipeline, and an alkali liquid reflux pump is provided on the alkali liquid reflux pipeline.

[0023] Preferably, the insulating working fluid is ethylene glycol solution or R141b.

[0024] The present invention also provides a method for efficiently producing hydrogen using an immersed alkaline electrolyzer, using the above-mentioned efficient hydrogen production system using an immersed alkaline electrolyzer, the method comprising:

[0025] During the preheating, hot standby and low operating temperature conditions of the alkaline electrolysis hydrogen production system:

[0026] The heat source in the heat exchanger assembly heats the insulating medium; the heated insulating medium flows into the immersion tank to heat the alkaline electrolytic cell completely immersed in the insulating medium; the insulating medium flowing out of the immersion tank heats the alkali solution in the alkali solution storage tank and maintains the temperature;

[0027] Under the condition that the alkaline electrolytic cell operates at a high temperature under variable load: the heat source in the heat exchanger assembly cools the insulating working medium; the cooled insulating working medium flows into the immersion tank to cool the alkaline electrolytic cell completely immersed in the insulating working medium; the insulating working medium flowing out of the immersion tank cools the alkali solution in the alkali solution storage tank and maintains its temperature.

[0028] Preferably, the heat exchanger assembly includes a cold source heat exchanger and a hot source heat exchanger, wherein the cold source heat exchanger is provided with a first cold extraction coil, and the hot source heat exchanger is provided with a hot extraction coil;

[0029] The method further includes:

[0030] Under the conditions of preheating, hot standby and low operating temperature of the alkaline electrolysis hydrogen production system: the heat extraction coil, the immersion tank and the temperature control coil are connected to form a heating circuit, and the alkaline electrolytic cell is heated in situ through the heating circuit, and the alkali solution is heated and maintained at the same time;

[0031] Under the condition that the alkaline electrolytic cell is operated at a high temperature under variable load, the first cooling coil, the immersion tank and the temperature regulating coil are connected to form a first cooling circuit, and the alkaline electrolytic cell is cooled in situ through the first cooling circuit, and the alkali solution is cooled and the temperature is maintained at the same time.

[0032] The high-efficiency hydrogen production system and method using an immersed alkaline electrolyzer provided by the present invention have the following beneficial effects compared with the prior art: the alkaline electrolyzer of the system is located in an immersion tank, and the heat exchanger assembly can cool or heat the insulating working fluid, and the insulating working fluid directly transfers heat to the alkaline electrolyzer immersed therein, thereby realizing in-situ temperature control of the alkaline electrolyzer; the insulating working fluid flowing through the temperature regulating coil can exchange heat with the alkaline solution in the alkaline solution storage tank, thereby realizing both the heating and temperature control of the alkaline solution and the in-situ heating and temperature control of the alkaline electrolyzer, thereby greatly improving the system variable load response speed of the alkaline electrolysis hydrogen production system under working conditions such as preheating, hot standby and low operating temperature, thereby meeting the requirements for efficient and safe operation and regulation of dynamic variable load of large-scale alkaline electrolyzer hydrogen production. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 This is a schematic diagram of the structure of an efficient hydrogen production system using an immersed alkaline electrolyzer;

[0035] Figure 2 This is a schematic diagram of the first cooling circuit operating alone;

[0036] Figure 3 This is a schematic diagram of the heating circuit running alone

[0037] Figure 4 This is a schematic diagram of the second cooling circuit operating independently.

[0038] In the figure, 1. alkaline electrolyzer; 2. immersion tank; 3. insulating medium; 4. hydrogen separator; 41. hydrogen cooling coil; 42. first droplet catcher; 5. oxygen separator; 51. oxygen cooling coil; 52. second droplet catcher; 6. alkali solution reflux pump; 7. alkali solution storage tank; 71. temperature control coil; 8. alkali solution supply pump; 9. cold source heat exchanger; 91. first cold extraction coil; 92. second cold extraction coil; 10. heat source heat exchanger; 101. heat extraction coil; 11. second expansion tank; 12. first expansion tank; 13. cooling circuit pump; 14. cooling circuit supply valve; 15. first return valve; 16. heating circuit pump; 17. heating circuit supply valve; 18. second return valve; 19. separator cooling circulation pump. DETAILED DESCRIPTION

[0039] To make the objectives, technical solutions, and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other implementations obtained by those of ordinary skill in the art without inventive effort are within the scope of protection of the present invention.

[0040] In the description of the present invention, it should be understood that the terms "center," "length," "width," "height," "up," "down," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inside," "outside," and "side" and the like, indicating positions or location relationships, are based on the positions or location relationships shown in the accompanying drawings and are intended only to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as limiting the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0041] The embodiment of the present invention provides an efficient hydrogen production system using an immersed alkaline electrolyzer, which simultaneously realizes the heating and temperature control of the alkali solution and the in-situ heating and temperature control of the alkaline electrolyzer, greatly improving the system variable load response speed of the alkaline electrolysis hydrogen production system under working conditions such as preheating, hot standby and low operating temperature.

[0042] The following combination Figures 1-4 The technical solution provided by the present invention is described in more detail.

[0043] Embodiment 1:

[0044] like Figures 1-4 As shown in the figure, the thick solid line represents the flow path of the alkaline solution (electrolyte), and the thin solid line represents the flow path of the insulating medium.

[0045] The present invention provides an immersion-type alkaline electrolyzer high-efficiency hydrogen production system, comprising an alkaline electrolyzer 1, an immersion tank 2, an alkali solution storage tank 7, and a heat exchanger assembly having a cold source or a heat source, wherein: the immersion tank 2 is filled with a liquid insulating working medium 3, the alkaline electrolyzer 1 is located in the immersion tank 2 and is completely immersed in the insulating working medium 3; the alkali solution outlet of the alkali solution storage tank 7 is connected to the alkali solution inlet of the alkaline electrolyzer 1, and an alkali solution supply pump 8 is provided on the connecting pipeline between the two; a temperature regulating coil 71 is provided in the alkali solution storage tank 7, the heat exchanger assembly, the immersion tank 2, and the temperature regulating coil 71 are sequentially connected along the flow direction of the insulating working medium 3, the heat exchanger assembly is used to cool or heat the insulating working medium 3, and the insulating working medium 3 flowing through the temperature regulating coil 71 can exchange heat with the alkali solution in the alkali solution storage tank 7.

[0046] The alkaline electrolytic cell 1 is completely immersed in the insulating medium 3 in the immersion tank 2 to keep the alkaline electrolytic cell 1 isolated from the air, thereby improving operation safety and corrosion resistance, and realizing in-situ temperature control of the alkaline electrolytic cell 1 through immersed convection heat exchange of the insulating medium 3.

[0047] The present invention does not involve innovation in the power supply for hydrogen production, so the power supply form of the alkaline electrolyzer 1 is not separately drawn. As an existing mature technology, the power supply form of the alkaline electrolyzer 1 is not limited here.

[0048] There is a heat source or a cold source, or a heat exchange medium capable of adjusting the temperature, in the heat exchanger assembly, thereby heating or cooling the insulating working medium 3.

[0049] As an optional embodiment, Figures 1-4 As shown, the heat exchanger assembly includes a cold source heat exchanger 9 and a hot source heat exchanger 10. The cold source heat exchanger 9 is used to cool the insulating working medium 3, thereby realizing in-situ cooling of the alkaline electrolytic cell 1. The insulating working medium 3 flowing through the temperature regulating coil 71 can exchange heat with the alkali liquid in the alkali liquid storage tank 7, thereby cooling the alkali liquid; the heat source heat exchanger 10 is used to heat the insulating working medium 3, thereby realizing in-situ heating of the alkaline electrolytic cell 1. The insulating working medium 3 flowing through the temperature regulating coil 71 can exchange heat with the alkali liquid in the alkali liquid storage tank 7, thereby heating the alkali liquid.

[0050] Specifically, such as Figures 1-4 As shown, the heat source heat exchanger 10 in the present invention obtains and stores heat energy from an external heat source. The external heat source can be a device or system that provides heat energy in a broad sense, such as various types of industrial waste heat, solar thermal energy, and electric heating; the cold source heat exchanger 9 obtains and stores cold energy from an external cold source. The external cold source can be a device or system that provides cold energy in a broad sense, such as a natural cold source, electric compression refrigeration or waste heat, photothermal energy, and other absorption-type cold energy. Changing the form of the heat source or cold source or the form of the heat source heat exchanger 10 and the cold source heat exchanger 9 cannot replace the original idea and scope of protection of the present invention.

[0051] like Figures 1-4 As shown, a first cold coil 91 is provided in the cold source heat exchanger 9, and the cold source outlet of the first cold coil 91 is connected to the immersion tank 2 through a cold source liquid inlet pipe, and has a connected or blocked state. The cold source inlet of the cold source heat exchanger 9 is connected to the temperature regulating coil 71 through a cold source liquid outlet pipe, and has a connected or blocked state; when the first cold coil 91, the immersion tank 2 and the temperature regulating coil 71 are all connected, a first cooling circuit can be formed.

[0052] The first cooling coil 91 is located in the cold source heat exchanger 9 and exchanges heat with the cold source to cool the insulating medium 3. The temperature regulating coil 71 is located in the alkali solution storage tank 7 to exchange heat with the insulating medium 3. Figure 2 As shown, after the insulating medium 3 is cooled, it flows into the immersion tank 2 to cool the alkaline electrolytic cell 1 in situ. The insulating medium 3 continues to flow into the temperature regulating coil 71 to cool the alkali solution stored in the alkali solution storage tank 7. At the same time, the cooling of the alkali solution and the in-situ cooling of the alkaline electrolytic cell 1 are achieved.

[0053] See also Figure 1 and Figure 2As shown, as an optional implementation, a cooling circuit pump 13 and a cooling circuit liquid supply valve 14 are provided on the outlet pipe section of the first cooling coil 91, and a first return liquid valve 15 is provided on the inlet pipe section of the first cooling coil 91. When the cooling circuit pump 13, the cooling circuit liquid supply valve 14 and the first return liquid valve 15 are all opened, the first cooling coil 91, the immersion tank 2 and the temperature control coil 71 are connected; the first cooling circuit is connected to the first expansion tank 12, and the first expansion tank 12 is located between the first cooling coil 91 and the immersion tank 2.

[0054] In this embodiment, the first cooling coil 91, the cooling circuit pump 13, the cooling circuit liquid supply valve 14, the first expansion tank 12, the immersion tank 2, the temperature control coil 71, the cooling circuit liquid supply valve 14 and the corresponding pipelines form a first cooling circuit, which is used to meet the cooling and temperature control requirements of the alkali solution and the alkaline electrolytic cell 1 under different operating conditions.

[0055] As an alternative embodiment, see Figure 1 and Figure 3 As shown, the heat source heat exchanger 10 has a heat extraction coil 101, and the heat source outlet of the heat extraction coil 101 is connected to the immersion tank 2 through a heat source liquid inlet pipe, and can be connected or blocked. The heat source inlet of the heat source heat exchanger 10 is connected to the temperature control coil 71 through a heat source liquid outlet pipe, and can be connected or blocked. When the heat extraction coil 101, the immersion tank 2 and the temperature control coil 71 are all connected, a heating circuit can be formed.

[0056] The heat extraction coil 101 is located in the heat source heat exchanger 10 and exchanges heat with the heat source to achieve the temperature increase of the insulating medium 3. The temperature control coil 71 is located in the alkali solution storage tank 7 to achieve heat exchange between the insulating medium 3 and the alkali solution. Figure 3 As shown, after the insulating medium 3 is heated by exchanging heat with the heat source in the heat source heat exchanger 10, it flows into the immersion tank 2 to heat the alkaline electrolytic cell 1 in situ. The insulating medium 3 continues to flow into the temperature control coil 71 to heat the alkali solution stored in the alkali solution storage tank 7. Simultaneously, the alkali solution is heated and the alkaline electrolytic cell 1 is heated in situ.

[0057] As an alternative embodiment, see Figure 1 and Figure 3 As shown, a heating circuit pump 16 and a heating circuit liquid supply valve 17 are provided on the outlet pipe section of the heat extraction coil 101, and a second liquid return valve 18 is provided on the inlet pipe section of the heat extraction coil 101. When the heating circuit pump 16, the heating circuit liquid supply valve 17 and the second liquid return valve 18 are all opened, the heat extraction coil 101, the immersion tank 2 and the temperature control coil 71 are connected.

[0058] The heat extraction coil 101, the heating circuit pump 16, the heating circuit liquid supply valve 17, the first expansion tank 12, the immersion tank 2, the temperature control coil 71, and the second liquid return valve 18 constitute a heating circuit, which is used to meet the heating and temperature control requirements of the alkali solution and the alkaline electrolytic cell 1 under different operating conditions.

[0059] As an alternative embodiment, see Figure 1 and Figure 4 As shown, the submerged alkaline electrolyzer efficient hydrogen production system of this embodiment also includes a hydrogen separator 4 and an oxygen separator 5, wherein: the hydrogen separator 4 is connected to the hydrogen outlet of the alkaline electrolyzer 1, and the oxygen separator 5 is connected to the oxygen outlet of the alkaline electrolyzer 1; a hydrogen cooling coil 41 is provided in the hydrogen separator 4, an oxygen cooling coil 51 is provided in the oxygen separator 5, a second cooling coil 92 is provided in the cold source heat exchanger 9, the second cooling coil 92, the hydrogen cooling coil 41 and the oxygen cooling coil 51 are connected in sequence to form a second cooling circuit; a separator cooling circulation pump 19 and a second expansion tank 11 are provided on the second cooling circuit.

[0060] The cooling coil, the separator cooling circulation pump 19, the second expansion tank 11, the hydrogen cooling coil 41, and the oxygen cooling coil 51 constitute a second cooling circuit, which is used to cool the hydrogen in the hydrogen separator 4 and the oxygen in the oxygen separator 5 and promote the condensation and separation of the alkali liquid vapor in the hydrogen separator 4 and the oxygen separator 5.

[0061] The insulating medium 3 in the second cooling coil 92 and the first cooling coil 91 is cooled in the cold source heat exchanger 9 . The structure is simple, and there is no need to set up an additional cold source heat exchanger 9 . The structure is compact.

[0062] The first cooling circuit, the second cooling circuit, the immersion tank 2 and the heating circuit are all filled with an insulating working medium 3 such as ethylene glycol solution, R141b, etc., which serves as an electrically insulating heat exchange medium for heating and cooling.

[0063] The role of the first expansion tank 12 in the first cooling circuit and the second expansion tank 11 in the second cooling circuit is to maintain stable operation of the system, buffer pressure fluctuations caused by changes in the volume of the coolant, and ensure the sealing and safety of the system. Stabilize system pressure: When the coolant expands due to heat, the increase in volume causes the system pressure to rise. The expansion tank prevents a sudden increase in pressure by storing excess coolant; when the coolant cools down and contracts, the pre-filled gas in the tank pushes the stored coolant back into the system to avoid excessively low pressure. Prevent the risk of explosion: The violent expansion of coolant under high temperature may cause the pipe or radiator to rupture. The expansion tank acts as a buffer container to release excess pressure through a pressure relief valve (usually located on the expansion tank cap) to protect the structural integrity of the system.

[0064] As an optional embodiment, a first droplet catcher 42 is provided within hydrogen separator 4, and a second droplet catcher 52 is provided within oxygen separator 5. Both hydrogen separator 4 and oxygen separator 5 are connected to an alkali liquid storage tank 7 via an alkali liquid return line, which is provided with an alkali liquid return pump 6. The first droplet catcher 42 and the second droplet catcher 52 are conventional, mature technologies used for condensing and separating the liquid phase within the gas.

[0065] After the insulating working medium 3 in the second cooling circuit is cooled by the second cooling coil 92, it flows through the separator cooling circulation pump 19, the second expansion tank 11, the hydrogen cooling coil 41, and the oxygen cooling coil 51 in sequence, and finally flows back to the second cooling coil 92 to complete the hydrogen and oxygen gas cooling cycle. This cycle not only achieves efficient cooling of hydrogen and oxygen, but also reduces the saturated vapor pressure of alkali liquid vapor carried in the gas through cooling and cooling in the hydrogen separator 4 and the oxygen separator 5, promotes condensation of alkali liquid vapor and agglomeration of droplets, and improves the droplet collection efficiency of the first droplet catcher 42 and the second droplet catcher 52, thereby improving the gas-liquid separation efficiency in the hydrogen separator 4 and the oxygen separator 5, and reducing the operating load of the subsequent gas purification process.

[0066] The separated alkali liquid is refluxed into the alkali liquid storage tank 7 through the alkali liquid reflux pump 6, thereby reducing the waste of alkali liquid.

[0067] The efficient hydrogen production method based on the submerged alkaline electrolyzer 1 proposed in the present invention simultaneously realizes in-situ temperature control of the alkaline electrolyzer 1, temperature control of the electrolyte, and efficient pre-cooling and separation of the hydrogen separator 4 and the oxygen separator 5. It has the outstanding advantages of fast dynamic load response, high hydrogen production efficiency, high operating efficiency of the hydrogen-oxygen separator 5, and safe operation, and has broad application prospects.

[0068] Example 2:

[0069] This embodiment provides a method for efficiently producing hydrogen using an immersed alkaline electrolyzer 1, using the above-mentioned immersed alkaline electrolyzer efficient hydrogen production system. The method includes: when the alkaline electrolysis hydrogen production system is preheating, hot standby, or operating at a relatively low temperature: causing the heat source in the heat exchanger assembly to heat the insulating working medium 3; causing the heated insulating working medium 3 to flow into the immersion tank 2 to heat the alkaline electrolyzer 1 completely immersed in the insulating working medium 3; causing the insulating working medium 3 flowing out of the immersion tank 2 to heat the alkali solution in the alkali solution storage tank 7 and maintain its temperature; when the alkaline electrolyzer 1 is operating at a relatively high temperature under variable load: causing the heat source in the heat exchanger assembly to cool the insulating working medium 3; causing the cooled insulating working medium 3 to flow into the immersion tank 2 to cool the alkaline electrolyzer 1 completely immersed in the insulating working medium 3; causing the insulating working medium 3 flowing out of the immersion tank 2 to cool the alkali solution in the alkali solution storage tank 7 and maintain its temperature.

[0070] As an alternative embodiment, see Figure 1 and Figure 3 As shown, the method further includes: when the alkaline electrolysis hydrogen production system is preheated, in hot standby mode, or in a relatively low operating temperature, the heat extraction coil 101, the immersion tank 2, and the temperature control coil 71 are connected to form a heating circuit, and the alkaline electrolytic cell 1 is heated in situ by the heating circuit, and the alkali solution is heated and maintained at the same time; when the alkaline electrolytic cell 1 is operated at a relatively high temperature under variable load, the first cooling coil 91, the immersion tank 2, and the temperature control coil 71 are connected to form a first cooling circuit, and the alkaline electrolytic cell 1 is cooled in situ by the first cooling circuit, and the alkali solution is cooled and maintained at the same time.

[0071] For details, see Figure 1 and Figure 3 As shown, under the operating conditions of preheating, hot standby and low operating temperature of the alkaline electrolysis hydrogen production system, the cooling circuit pump 13, the cooling circuit liquid supply valve 14 and the first liquid return valve 15 on the first cooling circuit are closed, and the heating circuit pump 16, the heating circuit liquid supply valve 17 and the second liquid return valve 18 on the heating circuit are opened. Driven by the heating circuit pump 16, the insulating working medium 3 flows through the heat extraction coil 101 to extract heat from the heat source, and flows through the heating circuit liquid supply valve 17 and the first expansion tank 12 to enter the immersion tank 2, and part of the heat is heated and temperature-controlled to the alkaline electrolytic cell 1 through immersion convection heat exchange. Then, the insulating working medium 3 flows through the temperature control coil 71 in the alkali solution storage tank 7 to heat the alkali solution and maintain the temperature, and finally flows back to the heat extraction coil 101 through the second liquid return valve 18 to complete the heating and temperature control cycle of the insulating working medium 3. Compared with traditional alkali solution preheating, this cycle realizes the alkali solution heating temperature control and the in-situ heating temperature control of the electrolyzer at the same time, which greatly improves the system variable load response speed of the alkaline electrolysis hydrogen production system under preheating, hot standby and low operating temperature conditions, and meets the dynamic variable load efficient and safe operation and control requirements of large-scale alkaline electrolyzer 1 hydrogen production.

[0072] When the alkaline electrolyzer 1 is under variable load and high temperature conditions, the heating circuit pump 16, the heating circuit liquid supply valve 17, and the second liquid return valve 18 on the heating circuit are closed, and the cooling circuit pump 13, the cooling circuit liquid supply valve 14, and the first liquid return valve 15 on the first cooling circuit are opened. The first cooling coil 91 in the first cooling circuit absorbs cold energy from the cold source heat exchanger 9, and the cold energy is returned to the first cooling coil 91 through the cooling circuit pump 13, the cooling circuit liquid supply valve 14, the first expansion tank 12, the immersion tank 2, the alkali liquid tank temperature control coil 71, and the first liquid return valve 15 to complete the cycle. This cycle simultaneously realizes the immersion cooling temperature control of the alkaline electrolyzer 1 and the cooling of the alkali liquid in the alkali liquid tank, so that the system always maintains a suitable operating temperature range even under the condition of hydrogen production load fluctuation of the alkaline electrolyzer 1, thereby improving the operating efficiency and safety of the alkaline electrolysis hydrogen production system.

[0073] As an optional embodiment, the method further includes, referring to Figure 1and Figure 4 As shown, the second cooling circuit is used to cool the gas in the hydrogen separator 4 and the oxygen separator 5, thereby reducing the saturated vapor pressure of the alkali liquid vapor carried in the gas.

[0074] After the insulating working medium 3 in the second cooling circuit is cooled by the second cooling coil 92, it flows through the liquid supply pump, the second expansion tank 11, the hydrogen cooling coil 41, the oxygen cooling coil 51 in sequence, and finally flows back to the second cooling coil 92 to complete the hydrogen and oxygen gas cooling cycle. This cycle not only achieves efficient cooling of hydrogen and oxygen, but also reduces the saturated vapor pressure of alkali liquid vapor carried in the gas through cooling in the hydrogen separator 4 and the oxygen separator 5, promotes condensation of alkali liquid vapor and agglomeration of droplets, and improves the droplet capture efficiency of the droplet collector, thereby improving the gas-liquid separation efficiency in the hydrogen separator 4 and the oxygen separator 5, and reducing the operating load of the subsequent gas purification process.

[0075] In the description of this specification, specific features, structures or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0076] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction 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 any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0077] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. An efficient hydrogen production system using an immersed alkaline electrolyzer, characterized in that: Includes alkaline electrolysis cells, immersion tanks, alkali liquid storage tanks, and heat exchanger components with cold or hot sources, wherein: The immersion tank is filled with a liquid insulating medium, and the alkaline electrolytic cell is located in the immersion tank and is completely immersed in the insulating medium; The alkali liquid outlet of the alkali liquid storage tank is connected to the alkali liquid inlet of the alkaline electrolytic cell. A temperature regulating coil is provided in the alkali liquid storage tank. The heat exchanger assembly, the immersion tank, and the temperature regulating coil are sequentially connected along the flow direction of the insulating working medium. The heat exchanger assembly is used to cool or heat the insulating working medium. The insulating working medium flowing through the temperature regulating coil can exchange heat with the alkali liquid in the alkali liquid storage tank.

2. The high-efficiency hydrogen production system using an immersion alkaline electrolyzer according to claim 1, characterized in that: The heat exchanger assembly includes a cold source heat exchanger, wherein: A first cold coil is provided in the cold source heat exchanger, wherein the cold source outlet of the first cold coil is connected to the immersion tank via a cold source liquid inlet pipe, and can be in a connected or blocked state; the cold source inlet of the cold source heat exchanger is connected to the temperature regulating coil via a cold source liquid outlet pipe, and can be in a connected or blocked state; When the first cooling coil, the immersion tank and the temperature regulating coil are all connected, a first cooling circuit can be formed.

3. The high-efficiency hydrogen production system using an immersion alkaline electrolyzer according to claim 1, characterized in that: The heat exchanger assembly includes a heat source heat exchanger, wherein the heat source heat exchanger has a heat extraction coil, the heat source outlet of the heat extraction coil is connected to the immersion tank via a heat source liquid inlet pipe, and can be in a connected or blocked state, and the heat source inlet of the heat source heat exchanger is connected to the temperature regulating coil via a heat source liquid outlet pipe, and can be in a connected or blocked state; The heat extraction coil, the immersion tank and the temperature regulating coil are all connected to form a heating circuit.

4. The high-efficiency hydrogen production system using an immersion alkaline electrolyzer according to claim 2, characterized in that: The outlet pipe section of the first cooling coil is provided with a cooling circuit pump and a cooling circuit liquid supply valve, and the inlet pipe section of the first cooling coil is provided with a first liquid return valve. When the cooling circuit pump, the cooling circuit liquid supply valve, and the first liquid return valve are all opened, the first cooling coil, the immersion tank, and the temperature regulating coil are connected; The first cooling circuit is connected to a first expansion tank, and the first expansion tank is located between the first cooling coil and the immersion tank.

5. The high-efficiency hydrogen production system using an immersion alkaline electrolyzer according to claim 3, characterized in that: A heating circuit pump and a heating circuit liquid supply valve are provided on the outlet pipe section of the heat extraction coil, and a second liquid return valve is provided on the inlet pipe section of the heat extraction coil. When the heating circuit pump, the heating circuit liquid supply valve and the second liquid return valve are all opened, the heat extraction coil, the immersion tank and the temperature control coil are connected.

6. The high-efficiency hydrogen production system using an immersion alkaline electrolyzer according to claim 2, characterized in that: The submerged alkaline electrolyzer efficient hydrogen production system further includes a hydrogen separator and an oxygen separator, wherein: The hydrogen separator is connected to the hydrogen outlet of the alkaline electrolyzer, and the oxygen separator is connected to the oxygen outlet of the alkaline electrolyzer; a hydrogen cooling coil is provided in the hydrogen separator, an oxygen cooling coil is provided in the oxygen separator, and a second cooling coil is provided in the cold source heat exchanger. The second cooling coil, the hydrogen cooling coil, and the oxygen cooling coil are connected in sequence to form a second cooling circuit; The second cooling circuit is provided with a separator cooling circulation pump and a second expansion tank.

7. The high-efficiency hydrogen production system using an immersion alkaline electrolyzer according to claim 6, characterized in that: A first liquid droplet catcher is provided in the hydrogen separator, a second liquid droplet catcher is provided in the oxygen separator, the hydrogen separator and the oxygen separator are both connected to the alkali liquid storage tank through an alkali liquid reflux pipeline, and an alkali liquid reflux pump is provided on the alkali liquid reflux pipeline.

8. The high-efficiency hydrogen production system using an immersion alkaline electrolyzer according to claim 1, characterized in that: The insulating working fluid is ethylene glycol solution or R141b.

9. A method for efficiently producing hydrogen using an immersed alkaline electrolyzer, characterized in that: Using the submerged alkaline electrolyzer efficient hydrogen production system according to any one of claims 1 to 8, the method comprises: During the preheating, hot standby and low operating temperature conditions of the alkaline electrolysis hydrogen production system: The heat source in the heat exchanger assembly heats the insulating medium; the heated insulating medium flows into the immersion tank to heat the alkaline electrolytic cell completely immersed in the insulating medium; the insulating medium flowing out of the immersion tank heats the alkali solution in the alkali solution storage tank and maintains the temperature; Under the condition that the alkaline electrolytic cell operates at a high temperature under variable load: the heat source in the heat exchanger assembly cools the insulating working medium; the cooled insulating working medium flows into the immersion tank to cool the alkaline electrolytic cell completely immersed in the insulating working medium; the insulating working medium flowing out of the immersion tank cools the alkali solution in the alkali solution storage tank and maintains its temperature.

10. The method for efficiently producing hydrogen using an immersed alkaline electrolyzer according to claim 9, wherein: The heat exchanger assembly includes a cold source heat exchanger and a hot source heat exchanger, wherein the cold source heat exchanger is provided with a first cold extraction coil, and the hot source heat exchanger is provided with a hot extraction coil; The method further includes: Under the conditions of preheating, hot standby and low operating temperature of the alkaline electrolysis hydrogen production system: the heat extraction coil, the immersion tank and the temperature control coil are connected to form a heating circuit, and the alkaline electrolytic cell is heated in situ through the heating circuit, and the alkali solution is heated and maintained at the same time; Under the condition that the alkaline electrolytic cell is operated at a high temperature under variable load, the first cooling coil, the immersion tank and the temperature regulating coil are connected to form a first cooling circuit, and the alkaline electrolytic cell is cooled in situ through the first cooling circuit, and the alkali solution is cooled and the temperature is maintained at the same time.

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