Modularized partitioned seawater hydrogen production system and multi-loop decoupling regulation and control method thereof

Abstract

The invention discloses a modularized partitioned seawater hydrogen production system and a multi-loop decoupling regulation and control method thereof. The system comprises an alkali liquor hydrogen production electrolytic bath, an alkali liquor regeneration pump, a pressure pump, a pressure reduction pump and a PLC control cabinet, wherein the alkali liquor hydrogen production electrolytic tank and the alkali liquor regeneration pump are connected through the pressure pump and the pressure reduction pump to form an end-to-end circulation loop; the alkali liquor regeneration pump is positioned in seawater; the dynamic balance of the pure water supplementing speed is controlled by changing the valve opening degree of the pressure pump; the temperature of the alkali liquor hydrogen production electrolytic tank is controlled by changing the valve opening degree of the pressure reduction pump to be constant; the dynamic balance of the concentration of the alkali liquor in the alkali liquor hydrogen production electrolytic bath and the alkali liquor regeneration pump is controlled by changing the exchange area between the alkali liquor in the alkali liquor regeneration pump and the seawater; sensor information is processed through the PLC control cabinet, and a control signal is sent out, so that seawater hydrogen production is realized. According to the invention, the concentration of alkali liquor in the alkali liquor hydrogen production electrolytic bath can be maintained near the concentration with the highest hydrogen production efficiency, and high-efficiency seawater hydrogen production is realized.

Description

Technical Field

[0001] This invention belongs to the field of seawater electrolysis hydrogen production technology in the new energy sector, and particularly relates to a modular zoned seawater hydrogen production system and its multi-loop decoupling control method. Background Technology

[0002] For a long time, hydrogen production through water electrolysis has been constrained by both electricity and freshwater resource consumption, making it economically difficult to compete with hydrogen production from fossil fuels. Compared to traditional processes such as steam methane reforming or coal gasification, hydrogen production through water electrolysis based on renewable energy sources (such as wind power and photovoltaic coupled electrolyzers) has significant advantages in terms of zero carbon emissions and high-purity hydrogen production. Its greenhouse gas emissions per unit mass of hydrogen produced are only 1 / 5 to 1 / 3 of those from steam methane reforming. With the breakthrough in global renewable energy installed capacity, hydrogen production through water electrolysis, due to its ability to absorb intermittent power and its flexibility in grid coupling, has become a core technological path for "green hydrogen" production.

[0003] Seawater accounts for 97% of the Earth's total water resources. Direct seawater hydrogen production technology can reduce hydrogen production costs by more than 30% by eliminating reliance on freshwater. However, existing seawater hydrogen production technologies face two major bottlenecks: First, during alkaline electrolyzer operation, the electrolyte concentration fluctuates due to the consumption of pure water, leading to a decrease in conductivity and a reduction in electrolysis efficiency. Second, traditional membrane separation technologies (such as PTFE membranes) rely on static exchange area design and cannot dynamically respond to changes in electrolysis load caused by fluctuations in renewable energy power, resulting in an imbalance between water migration rate and consumption rate, and insufficient system stability.

[0004] To address the aforementioned shortcomings, this invention proposes a seawater hydrogen production system and control method. This design overcomes the limitations of static membrane systems, achieving dynamic and constant alkali concentration and stable conductivity; it eliminates the need for an independent cooling system; and it responds to fluctuations in renewable energy. This invention provides a key solution for large-scale hydrogen production from offshore wind power, supporting cost reductions in "green hydrogen" production. Summary of the Invention

[0005] The purpose of this invention is to address the problems of excessive byproducts, low electrolysis efficiency, and unstable operating conditions in existing seawater hydrogen production technologies by providing a modular, zoned seawater hydrogen production system and its multi-loop decoupling control method. This invention enables stable and efficient operation of seawater hydrogen production without traditional desalination facilities and under conditions of unstable energy availability.

[0006] The objective of this invention is achieved through the following technical solution: A first aspect of this invention provides a modular, zoned seawater hydrogen production system, including an alkaline hydrogen production electrolyzer, an alkaline regeneration pump, a booster pump, a depressurizer pump, and a PLC control cabinet; wherein the alkaline hydrogen production electrolyzer and the alkaline regeneration pump are connected via the booster pump and the depressurizer pump to achieve normal exchange of alkaline solution between the atmospheric pressure zone and the high pressure zone; the alkaline regeneration pump outputs the regenerated atmospheric pressure alkaline solution, which is then pressurized by the booster pump and sent into the alkaline hydrogen production electrolyzer; the alkaline solution after reaction in the alkaline hydrogen production electrolyzer is output... The water is depressurized by a step-down pump and then sent back to the alkali regeneration pump for processing. The alkali regeneration pump is placed in seawater to replenish the pure water consumed by electrolysis. The dynamic balance of the pure water replenishment rate is controlled by changing the valve opening of the booster pump. The temperature of the alkali hydrogen production electrolyzer is controlled by changing the valve opening of the depressurization pump. The dynamic balance of the alkali concentration in the alkali hydrogen production electrolyzer and the alkali regeneration pump is controlled by changing the exchange area between the alkali and seawater in the alkali regeneration pump. The sensor information is processed by the PLC control cabinet, and control signals are issued to realize seawater hydrogen production.

[0007] Furthermore, the alkaline hydrogen production electrolyzer includes a gas-liquid separator and an electrolyzer, wherein the gas-liquid separator and the electrolyzer are connected, the gas-liquid separator is connected to an alkaline regeneration pump via a pressurizing pump, and the electrolyzer is connected to the alkaline regeneration pump via a depressurizing pump.

[0008] Furthermore, the alkaline solution in the electrolytic cell is a 30% potassium hydroxide aqueous solution. During the seawater hydrogen production process, the pure water in the alkaline solution is electrolyzed into hydrogen and oxygen, and gas-liquid separation is achieved through a gas-liquid separator.

[0009] Furthermore, a first liquid level sensor is installed on the gas-liquid separator to detect the liquid level of the alkaline solution inside the gas-liquid separator; A temperature sensor is installed on the electrolytic cell to detect the temperature of the electrolytic cell; The alkali regeneration pump is equipped with a second liquid level sensor to detect the liquid level of the alkali solution inside the pump.

[0010] Furthermore, the alkali regeneration pump includes a cylindrical body, a mechanical structure for controlling the exchange area between the alkali and seawater, and a hydraulic pump; wherein, the mechanical structure is sleeved on the cylindrical body, and the hydraulic pump is connected to the mechanical structure; the mechanical structure is a double-layer cylindrical structure, including an inner layer of hydrophobic porous polytetrafluoroethylene membrane and an outer layer of metal shell, the hydrophobic porous polytetrafluoroethylene membrane is wrapped around the cylindrical body and fixed with iron rings, and a rubber pad is connected between the hydrophobic porous polytetrafluoroethylene membrane and the metal shell.

[0011] Furthermore, the PLC control cabinet is used to monitor the hydrogen production status of the seawater hydrogen production system in real time. Its control interface includes functions such as start / stop, reset, temperature and liquid level setting, and valve setting, and displays the detected liquid level, temperature, flow rate, current density, hydrogen production, and energy consumption data.

[0012] Furthermore, the change of the valve opening of the booster pump specifically includes: adjusting the valve opening of the booster pump according to the liquid level of the alkaline solution in the gas-liquid separator, the control law of which is:

[0013] In the formula, For the valve opening of the booster pump; For a PI controller, s is the Laplace operator. This is the proportional coefficient corresponding to the valve opening degree of the booster pump. This is the integral coefficient corresponding to the valve opening degree of the booster pump; Set the liquid level of the alkaline solution inside the gas-liquid separator. This represents the real-time liquid level of the alkaline solution inside the gas-liquid separator.

[0014] Furthermore, the change of the valve opening of the pressure reducing pump specifically includes: adjusting the valve opening of the pressure reducing pump according to the temperature of the electrolytic cell, wherein the control law is:

[0015] In the formula, The valve opening of the pressure reducing pump; For a PI controller, s is the Laplace operator. This is the proportional coefficient corresponding to the valve opening degree of the pressure reducing pump. This is the integral coefficient corresponding to the valve opening degree of the pressure reducing pump; This is the temperature setpoint for the electrolytic cell. This refers to the temperature of the real-time electrolytic cell.

[0016] Furthermore, the method of changing the exchange area between the alkali solution and seawater in the alkali regeneration pump specifically includes: installing a level valve on the alkali regeneration pump, and changing the valve opening to alter the exchange area between the alkali solution and seawater in the alkali regeneration pump; wherein, the valve opening is adjusted according to the alkali solution level in the alkali regeneration pump, and its control law is:

[0017] In the formula, This represents the valve opening degree of the level valve, which ranges from [0, 100%]. For a PI controller, s is the Laplace operator. This is the proportional coefficient corresponding to the valve opening degree of the level valve. This is the integral coefficient corresponding to the valve opening degree of the level valve; This is the setpoint for the alkali level in the alkali regeneration pump. This indicates the real-time level of the alkali solution inside the alkali regeneration pump.

[0018] A second aspect of this invention provides a multi-loop decoupling control method for the above-mentioned modular partitioned seawater hydrogen production system, specifically including: In the hydrogen production process of the alkaline solution electrolyzer, the liquid levels of the alkaline solution in the alkaline solution regeneration pump and the gas-liquid separator, as well as the temperature of the electrolyzer, are monitored in real time. The PLC control cabinet reads the liquid level of the alkaline solution in the gas-liquid separator, and the PI controller controls the valve opening of the booster pump based on the set value of the alkaline solution level in the gas-liquid separator to maintain a constant alkaline solution level. The PLC control cabinet reads the temperature of the electrolyzer, and the PI controller controls the valve opening of the pressure reducing pump based on the set value of the electrolyzer temperature to maintain a constant alkaline solution temperature. The PLC control cabinet reads the liquid level of the alkaline solution in the alkaline solution regeneration pump, and the PI controller controls the valve opening of the level valve based on the set value of the alkaline solution level in the alkaline solution regeneration pump to change the exchange area between the alkaline solution and seawater in the alkaline solution regeneration pump, thereby maintaining a constant alkaline solution level in the alkaline solution regeneration pump. This achieves a stable seawater hydrogen production process.

[0019] The beneficial effects of this invention are as follows: This invention controls the flow rate of the alkali solution channel by adjusting the valve opening of the pressurizing pump and the depressurizing pump, thereby achieving temperature control for heating and cooling. It controls the alkali solution concentration by controlling the liquid level of the alkali solution in the alkali regeneration pump and the gas-liquid separator. By controlling the valve opening of the level valve, it changes the effective exchange area between the alkali solution and seawater in the alkali regeneration pump, adjusting the online desalination rate of seawater. It also controls the dynamic balance between the water consumed in electrolytic hydrogen production and the pure water replenished in the alkali regeneration pump. Ultimately, this allows the alkali solution concentration in the alkali hydrogen production electrolyzer to be maintained at the highest efficiency concentration without the need for pure water replenishment. This achieves high-efficiency seawater hydrogen production while absorbing fluctuating marine renewable energy sources. Using the system described in this invention for seawater hydrogen production improves the ability to absorb fluctuating renewable energy sources, enhances the wide-range operation of seawater hydrogen production, and strengthens the electrolytic stability of seawater hydrogen production, enabling stable and efficient operation of seawater hydrogen production under wide power fluctuation conditions. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the modular partitioned seawater hydrogen production system of the present invention; Figure 2 This is a schematic diagram of the control interface of the PLC control cabinet of the present invention. Detailed Implementation

[0021] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the invention as detailed in the appended claims.

[0022] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular forms “a,” “the,” and “the” used in this invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0023] It should be understood that although the terms first, second, third, etc., may be used in this invention to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, first information may also be referred to as second information without departing from the scope of this invention, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to a determination."

[0024] The present invention will now be described in detail with reference to the accompanying drawings. Unless otherwise specified, the features of the following embodiments and implementations can be combined with each other. See Figure 1 The modular zoned seawater hydrogen production system of the present invention includes an alkaline hydrogen production electrolyzer, an alkaline regeneration pump, a booster pump, a depressurizer pump, and a PLC control cabinet. The system comprises an alkaline hydrogen production electrolyzer and an alkaline regeneration pump connected via a booster pump and a depressurizer pump to facilitate normal exchange of alkaline solution between the atmospheric and high-pressure zones. The alkaline regeneration pump outputs regenerated alkaline solution at atmospheric pressure, which is then pressurized by the booster pump and fed into the alkaline hydrogen production electrolyzer. The alkaline solution output from the electrolyzer after reaction is depressurized by the depressurizer pump and then returned to the alkaline regeneration pump for further processing. The alkaline regeneration pump is placed in seawater to replenish the pure water consumed during electrolysis. The dynamic balance of the pure water replenishment rate is controlled by adjusting the valve opening of the booster pump. The temperature of the alkaline hydrogen production electrolyzer is controlled by adjusting the valve opening of the depressurizer pump. The dynamic balance of the alkaline concentration in the alkaline hydrogen production electrolyzer and the alkaline regeneration pump is controlled by adjusting the exchange area between the alkaline solution and seawater within the alkaline regeneration pump. Sensor information is processed by a PLC control cabinet, and multi-loop decoupling control is used to issue control signals to achieve seawater hydrogen production.

[0025] Furthermore, the alkaline hydrogen production electrolyzer includes a gas-liquid separator and an electrolyzer, which is a high-pressure area. The gas-liquid separator and the electrolyzer are connected. The gas-liquid separator is connected to the alkaline regeneration pump through a pressurizing pump, and the electrolyzer is connected to the alkaline regeneration pump through a depressurizing pump.

[0026] Furthermore, the alkaline solution in the electrolyzer is a 30% (w / w) potassium hydroxide aqueous solution, containing a solvent (pure water) and a solute (solid potassium hydroxide). During the seawater hydrogen production process, the pure water in the alkaline solution is electrolyzed into hydrogen and oxygen, and gas-liquid separation is achieved through a gas-liquid separator. Pure water is continuously consumed and replenished from the alkaline solution regeneration pump via a pressure pump. During the seawater hydrogen production process, the temperature inside the electrolyzer continuously rises. The flow rate out of the electrolyzer is controlled by the valve opening of the pressure reducing pump, thus achieving temperature control during the operation of the electrolyzer.

[0027] Furthermore, a first liquid level sensor is installed on the gas-liquid separator to detect the liquid level of the alkaline solution inside the gas-liquid separator. Temperature sensors are installed on the electrolytic cell to detect its temperature. .

[0028] Furthermore, the alkali regeneration pump includes a cylindrical body, a mechanical structure for controlling the exchange area between the alkali and seawater, and a hydraulic pump. The mechanical structure is fitted onto the cylindrical body, and the hydraulic pump is connected to the mechanical structure, allowing the hydraulic pump to control the stroke of the mechanical structure. The mechanical structure is a double-layered cylindrical structure, consisting of an inner hydrophobic porous PTFE membrane and an outer metal shell. The hydrophobic porous PTFE membrane wraps around the cylindrical body and is secured with iron rings. The hydrophobic porous PTFE membrane blocks ion passage while allowing the exchange of water vapor molecules. Water vapor permeates from the side with higher ion concentration to the side with lower concentration. A rubber gasket connects the inner and outer layers, i.e., between the hydrophobic porous PTFE membrane and the metal shell, ensuring the alkali regeneration pump's sealing when alkali regeneration is not required. The complete alkali regeneration pump can be placed in various seawater environments to achieve alkali regeneration.

[0029] Furthermore, a second liquid level sensor is installed on the alkali regeneration pump to detect the liquid level of the alkali solution inside the pump. .

[0030] Furthermore, the PLC control cabinet is used to monitor the hydrogen production status of the seawater hydrogen production system in real time. Its control interface includes functions such as start / stop, reset, temperature and level setting, and valve setting, displaying data such as the detected liquid level, temperature, flow rate, current density, hydrogen production, and energy consumption. Figure 2 As shown.

[0031] Furthermore, changing the valve opening of the booster pump specifically includes adjusting the valve opening of the booster pump according to the liquid level of the alkaline solution in the gas-liquid separator. The control law is as follows:

[0032] In the formula, The valve opening of the booster pump is in the range of [0, 100%]; For a PI controller, s is the Laplace operator. This is the proportional coefficient corresponding to the valve opening degree of the booster pump. This is the integral coefficient corresponding to the valve opening degree of the booster pump; Set the liquid level of the alkaline solution inside the gas-liquid separator. This refers to the real-time level of the alkaline solution inside the gas-liquid separator. Specifically, when the level of the alkaline solution inside the gas-liquid separator is detected... When the value is higher than the corresponding set value, increase the valve opening of the booster pump. This allows the alkali solution in the alkali regeneration pump to be quickly replenished into the gas-liquid separator; when the alkali solution level in the gas-liquid separator is detected... When the value is lower than the corresponding set value, reduce the valve opening of the booster pump. This reduces the flow rate of alkali solution supplied from the alkali regeneration pump to the gas-liquid separator.

[0033] Furthermore, changing the valve opening of the pressure reducing pump specifically includes adjusting the valve opening of the pressure reducing pump according to the temperature of the electrolytic cell, with the control law being:

[0034] In the formula, The valve opening of the pressure reducing pump is in the range of [0, 100%]; For a PI controller, s is the Laplace operator. This is the proportional coefficient corresponding to the valve opening degree of the pressure reducing pump. This is the integral coefficient corresponding to the valve opening degree of the pressure reducing pump; This is the temperature setpoint for the electrolytic cell. This refers to the real-time temperature of the electrolytic cell. Specifically, when the temperature inside the electrolytic cell is detected... When the value is higher than the corresponding set value, increase the valve opening of the pressure reducing pump. This causes the high-temperature alkaline solution in the electrolytic cell to flow rapidly into the alkaline regeneration pump, achieving the purpose of heat dissipation; when the temperature inside the electrolytic cell is detected... When the value is lower than the corresponding set value, reduce the valve opening of the pressure reducing pump. This reduces the flow rate of the alkaline solution from the electrolytic cell to the alkaline regeneration pump, thus maintaining the temperature inside the electrolytic cell at the set value.

[0035] Furthermore, changing the exchange area between the alkali solution and seawater within the alkali regeneration pump specifically includes: installing a level valve on the alkali regeneration pump, and changing the valve opening to alter the exchange area between the alkali solution and seawater within the pump; wherein the valve opening is adjusted according to the alkali solution level within the pump, and its control law is as follows:

[0036] In the formula, This represents the valve opening degree of the level valve, which ranges from [0, 100%]. For a PI controller, s is the Laplace operator. This is the proportional coefficient corresponding to the valve opening degree of the level valve. This is the integral coefficient corresponding to the valve opening degree of the level valve; This is the setpoint for the alkali level in the alkali regeneration pump. This refers to the real-time liquid level of the alkali solution inside the alkali regeneration pump. Specifically, when the liquid level inside the alkali regeneration pump... When the level is below the set value, the valve opening of the level valve is increased, allowing the outer metal shell to move up and down. The valve opening controls its stroke, increasing the exchange area between the alkali solution and seawater on both sides of the hydrophobic porous polytetrafluoroethylene membrane, thus accelerating the replenishment of water to the alkali regeneration pump. When the alkali level in the alkali regeneration pump... When the value is higher than the corresponding set value, the valve opening of the liquid level valve is reduced, which reduces the effective exchange area between the alkali and seawater on both sides of the hydrophobic porous polytetrafluoroethylene membrane, reduces the rate at which seawater is supplied to the alkali regeneration pump, and thus controls the dynamic balance of alkali concentration in the entire hydrogen production system.

[0037] It is worth mentioning that the present invention also provides a multi-loop decoupling control method for the modular partitioned seawater hydrogen production system in the above embodiments. This multi-loop decoupling control method specifically includes: during the hydrogen production process in the alkaline solution electrolyzer, real-time monitoring of the alkaline solution level in the alkaline solution regeneration pump, the alkaline solution level in the gas-liquid separator, and the temperature of the electrolyzer; the PLC control cabinet reads the alkaline solution level in the gas-liquid separator, and the PI controller controls the valve opening of the booster pump based on the gas-liquid separator level setpoint to maintain a constant alkaline solution level in the gas-liquid separator; the PLC control cabinet reads the temperature of the electrolyzer, and the PI controller controls the valve opening of the pressure reducing pump based on the electrolyzer temperature setpoint to control the alkaline solution temperature in the electrolyzer. The PLC control cabinet reads the level of the alkali solution in the alkali regeneration pump. The PI controller controls the valve opening of the level valve based on the set value of the alkali solution level in the alkali regeneration pump, thereby changing the exchange area between the alkali solution and seawater in the alkali regeneration pump and keeping the alkali solution level in the alkali regeneration pump constant. Since the alkali solution level in the alkali regeneration pump and the gas-liquid separator is constant, the electrolysis of water to produce hydrogen does not consume electrolyte, so the electrolyte concentration is constant. This allows the alkali hydrogen production process to maintain high conductivity conditions, realizing an online seawater desalination process and thus achieving a stable seawater hydrogen production process.

[0038] In summary, this invention uses a booster pump and a depressurizer pump to connect the alkaline hydrogen production electrolyzer and the alkaline regeneration pump. By controlling the effective exchange area between the alkaline regeneration pump and seawater and adjusting the pure water replenishment rate, a dynamic balance is achieved between the pure water consumption for electrolytic hydrogen production and the pure water replenishment in the alkaline regeneration pump. This ensures a constant alkaline concentration in the seawater hydrogen production process. Simultaneously, the depressurizer pump regulates the temperature of the alkaline hydrogen production electrolyzer to maintain a constant temperature, ultimately ensuring that the alkaline concentration in the alkaline hydrogen production electrolyzer is maintained near the highest efficiency concentration. This results in stable operation and high-efficiency seawater hydrogen production.

[0039] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A modular, zoned seawater hydrogen production system, characterized in that, The system includes an alkaline hydrogen production electrolyzer, an alkaline regeneration pump, a booster pump, a depressurizer pump, and a PLC control cabinet. The alkaline hydrogen production electrolyzer and the alkaline regeneration pump are connected via the booster and depressurizer pumps to ensure normal exchange of alkaline solution between the atmospheric and high-pressure zones. The alkaline regeneration pump outputs regenerated atmospheric-pressure alkaline solution, which is then pressurized by the booster pump and fed into the alkaline hydrogen production electrolyzer. The alkaline solution output from the electrolyzer after reaction is depressurized by the depressurizer pump and then sent back to the alkaline regeneration pump for further processing. The alkaline regeneration pump is placed in seawater to replenish the pure water consumed during electrolysis. The dynamic balance of the pure water replenishment rate is controlled by changing the valve opening of the booster pump. The temperature of the alkaline hydrogen production electrolyzer is controlled by changing the valve opening of the depressurizer pump. The dynamic balance of the alkaline concentration in the alkaline hydrogen production electrolyzer and the alkaline regeneration pump is controlled by changing the exchange area between the alkaline solution and seawater within the alkaline regeneration pump. The PLC control cabinet processes sensor information and sends control signals to achieve seawater-based hydrogen production.

2. The modular zoned seawater hydrogen production system according to claim 1, characterized in that, The alkaline hydrogen production electrolyzer includes a gas-liquid separator and an electrolyzer, wherein the gas-liquid separator and the electrolyzer are connected, the gas-liquid separator is connected to an alkaline regeneration pump via a pressurizing pump, and the electrolyzer is connected to an alkaline regeneration pump via a depressurizing pump.

3. The modular zoned seawater hydrogen production system according to claim 2, characterized in that, The alkaline solution in the electrolytic cell is a 30% potassium hydroxide aqueous solution. During the seawater hydrogen production process, the pure water in the alkaline solution is electrolyzed into hydrogen and oxygen, and gas-liquid separation is achieved through a gas-liquid separator.

4. The modular zoned seawater hydrogen production system according to claim 2, characterized in that, The gas-liquid separator is equipped with a first liquid level sensor for detecting the liquid level of the alkaline solution inside the gas-liquid separator. A temperature sensor is installed on the electrolytic cell to detect the temperature of the electrolytic cell; The alkali regeneration pump is equipped with a second liquid level sensor to detect the liquid level of the alkali solution inside the pump.

5. The modular zoned seawater hydrogen production system according to claim 1, characterized in that, The alkali regeneration pump includes a cylindrical body, a mechanical structure for controlling the exchange area between the alkali and seawater, and a hydraulic pump. The mechanical structure is fitted onto the cylindrical body, and the hydraulic pump is connected to the mechanical structure. The mechanical structure is a double-layer cylindrical structure, including an inner hydrophobic porous polytetrafluoroethylene membrane and an outer metal shell. The hydrophobic porous polytetrafluoroethylene membrane is wrapped around the cylindrical body and secured with iron rings. A rubber pad connects the hydrophobic porous polytetrafluoroethylene membrane and the metal shell.

6. The modular zoned seawater hydrogen production system according to claim 1, characterized in that, The PLC control cabinet is used to monitor the hydrogen production status of the seawater hydrogen production system in real time. Its control interface includes functions such as start / stop, reset, temperature and liquid level setting, and valve setting, and displays the detected liquid level, temperature, flow rate, current density, hydrogen production, and energy consumption data.

7. The modular zoned seawater hydrogen production system according to claim 1, characterized in that, The change of the valve opening of the booster pump specifically includes: adjusting the valve opening of the booster pump according to the liquid level of the alkaline solution in the gas-liquid separator, and the control law is as follows: ； In the formula, For the valve opening of the booster pump; For a PI controller, s is the Laplace operator. This is the proportional coefficient corresponding to the valve opening degree of the booster pump. This is the integral coefficient corresponding to the valve opening degree of the booster pump; Set the liquid level of the alkaline solution inside the gas-liquid separator. This represents the real-time liquid level of the alkaline solution inside the gas-liquid separator.

8. The modular zoned seawater hydrogen production system according to claim 1, characterized in that, The change of the valve opening of the pressure reducing pump specifically includes: adjusting the valve opening of the pressure reducing pump according to the temperature of the electrolytic cell, and the control law is as follows: ； In the formula, The valve opening of the pressure reducing pump; For a PI controller, s is the Laplace operator. This is the proportional coefficient corresponding to the valve opening degree of the pressure reducing pump. This is the integral coefficient corresponding to the valve opening degree of the pressure reducing pump; This is the temperature setpoint for the electrolytic cell. This refers to the temperature of the real-time electrolytic cell.

9. The modular zoned seawater hydrogen production system according to claim 1, characterized in that, The method of changing the exchange area between the alkali solution and seawater in the alkali regeneration pump specifically includes: installing a level valve on the alkali regeneration pump, and changing the valve opening to change the exchange area between the alkali solution and seawater in the alkali regeneration pump; wherein, the valve opening is adjusted according to the alkali solution level in the alkali regeneration pump, and its control law is: ； In the formula, This represents the valve opening degree of the level valve, which ranges from [0, 100%]. For a PI controller, s is the Laplace operator. This is the proportional coefficient corresponding to the valve opening degree of the level valve. This is the integral coefficient corresponding to the valve opening degree of the level valve; This is the setpoint for the alkali level in the alkali regeneration pump. This indicates the real-time level of the alkali solution inside the alkali regeneration pump.

10. A multi-loop decoupling control method for a modular partitioned seawater hydrogen production system according to any one of claims 1-9, characterized in that, Specifically, it includes: In the hydrogen production process of the alkaline solution electrolyzer, the liquid levels of the alkaline solution in the alkaline solution regeneration pump and the gas-liquid separator, as well as the temperature of the electrolyzer, are monitored in real time. The PLC control cabinet reads the liquid level of the alkaline solution in the gas-liquid separator, and the PI controller controls the valve opening of the booster pump based on the set value of the alkaline solution level in the gas-liquid separator to maintain a constant alkaline solution level. The PLC control cabinet reads the temperature of the electrolyzer, and the PI controller controls the valve opening of the pressure reducing pump based on the set value of the electrolyzer temperature to maintain a constant alkaline solution temperature. The PLC control cabinet reads the liquid level of the alkaline solution in the alkaline solution regeneration pump, and the PI controller controls the valve opening of the level valve based on the set value of the alkaline solution level in the alkaline solution regeneration pump to change the exchange area between the alkaline solution and seawater in the alkaline solution regeneration pump, thereby maintaining a constant alkaline solution level in the alkaline solution regeneration pump. This achieves a stable seawater hydrogen production process.

Images