Optimization control system and method for hydrogen content in oxygen of alkaline water electrolysis hydrogen production system

Abstract

The invention discloses an optimal control system and method for the hydrogen content in oxygen of an alkaline water electrolysis hydrogen production system. According to the optimal control system, a cooling water flow regulating valve, an alkali liquor heat exchanger, an alkali liquor circulating pump, a heater, an alkali liquor flow meter, an alkali liquor flow regulating valve, a temperature transmitter, a pressure transmitter, a hydrogen-in-oxygen detection instrument, an oxygen outlet film regulating valve, a vacuum degassing device and a controller are correspondingly arranged on an alkali water electrolysis hydrogen production system; key technological parameters such as current density, alkali liquor flow, tank temperature and system pressure in the operation process of the alkaline water electrolysis hydrogen production system are integrally regulated and controlled, and meanwhile hydrogen bubbles dissolved in alkali liquor in an alkali liquor circulation system are cooperatively treated, so that the hydrogen content in finally output oxygen is further greatly reduced, the efficiency of reducing the hydrogen content in the oxygen by the system is remarkably improved, and the energy consumption of the system is reduced. The safety of the system is ensured, and the performance of the system is improved.

Description

Technical Field

[0001] This invention relates to the field of hydrogen production technology via water electrolysis. More specifically, this invention relates to an optimized control system and method for controlling the hydrogen content in oxygen within an alkaline water electrolysis hydrogen production system. Background Technology

[0002] Hydrogen is a flammable and explosive gas. When its volume fraction in air is between 4.0% and 75.6%, it will explode upon contact with an ignition source. In alkaline water electrolysis hydrogen production systems, if the hydrogen content in the oxygen exceeds the limit, it can easily reach the explosive limit of hydrogen. Therefore, the hydrogen content in the oxygen directly affects the operational safety of hydrogen production.

[0003] When an alkaline electrolyzer operates at low load for an extended period, the electrolytic current and alkaline flow rate are low, resulting in less heat generation from the electrochemical reaction within the cell. This slows down the gas evolution rate and prolongs the residence time of hydrogen and oxygen at the electrolyte-membrane interface, leading to an increase in the hydrogen content in the oxygen. During fluctuating operating conditions, the electrode polarization state and alkaline flow rate become unstable, causing an imbalance between the generation and detachment rates of bubbles on the electrode surface. This increases the driving force for hydrogen permeation and also destabilizes the oxygen-hydrogen pressure difference, leading to a certain degree of cross-permeation of hydrogen or oxygen due to the pressure difference, further increasing the hydrogen content in the oxygen.

[0004] Currently, the main methods for controlling the reduction of hydrogen content in oxygen are as follows: (1) Improvement of electrolytic cell By inserting a third electrode into the anode chamber of the alkali tank to form a hydrogen-oxygen fuel cell circuit with the anode of the alkali tank, an electrochemical reverse reaction occurs, thereby reducing the hydrogen concentration in the oxygen in the alkaline water electrolysis hydrogen production system.

[0005] (2) BOP improvement An enhanced dehydrogenation pipeline accessory is added, using internally filled hydrogen-absorbing material for initial dehydrogenation of the gas-liquid mixture in the anode chamber. After mixing with the alkali solution, a deep dehydrogenation unit is installed, filled with catalytic or adsorbent resin for further dehydrogenation of the circulating alkali solution. A recombiner is added to the connecting pipe between the oxygen separator and the hydrogen separator; the catalyst in the recombiner allows hydrogen and oxygen to recombine to form water. An oxygen-hydrogen analyzer located at the gas output end of the oxygen preprocessor monitors the hydrogen content in the oxygen side of the electrolyzer, thereby controlling the alkali circulation pump, alkali cooler, and the pressure difference on the hydrogen-oxygen separation side.

[0006] (3) Control improvement The control strategies for each equipment parameter are written into the PLC to control the parameters of each device in the water electrolysis hydrogen production equipment. Alternatively, the alkaline solution temperature can be synchronously controlled and adjusted as the load decreases through the alkaline solution cooler. The two are tracked and adjusted according to a corresponding proportional relationship to ensure that the hydrogen in oxygen is controlled within the allowable safe range.

[0007] Existing research on reducing the hydrogen content in oxygen in water electrolysis hydrogen production systems mainly focuses on the optimization design of hydrogen production process routes. However, research on system optimization control has not fully considered the impact of various key parameters on the hydrogen content in oxygen, resulting in insufficient optimization control capabilities for reducing the hydrogen content in oxygen. Summary of the Invention

[0008] One object of the present invention is to solve at least the above-mentioned problems and to provide at least the advantages that will be described later.

[0009] Another objective of this invention is to provide an optimized control system and method for the hydrogen content in oxygen in an alkaline water electrolysis hydrogen production system, in order to solve the technical problem that the existing technology has insufficient ability to optimize and control the hydrogen content in oxygen in an alkaline water electrolysis hydrogen production system.

[0010] To achieve these objectives and other advantages according to the present invention, in one aspect, the present invention provides an optimized control system for the hydrogen content in oxygen in an alkaline water electrolysis hydrogen production system, configured on the water electrolysis hydrogen production system, the water electrolysis hydrogen production system comprising an electrolyzer, an oxygen separator connected to the oxygen outlet of the electrolyzer, an oxygen-side scrubber, an oxygen-side gas cooler, an oxygen-side gas-water separator, and a hydrogen separator, a hydrogen-side scrubber, a hydrogen-side gas cooler, and a hydrogen-side gas-water separator connected to the hydrogen outlet of the electrolyzer, including: The controller is in communication with the rectifier connected to the electrolytic cell; A cooling water flow regulating valve, an alkali heat exchanger, an alkali circulating pump, a heater, and an alkali flow meter are sequentially installed along the pipeline facing the inlet side of the electrolytic cell, and the cooling water flow regulating valve, the alkali circulating pump, the heater, and the alkali flow meter are respectively connected to the controller for communication. An alkaline solution flow regulating valve is installed between the alkaline solution circulating pump and the hydrogen separator, and is connected in communication with the controller; A temperature transmitter is installed between the electrolytic cell and the oxygen separator and is connected in communication with the controller. A pressure transmitter is installed between the oxygen separator and the oxygen-side scrubber and is connected in communication with the controller. An oxygen-hydrogen detection instrument and an oxygen outlet membrane regulating valve are installed at the outlet of the oxygen-side gas-water separator and are connected to the controller. A vacuum degassing device is installed at the bottom of the hydrogen separator where the alkaline outlet is located before the alkaline collection port of the oxygen separator. The vacuum degassing device includes a vertical shell with a rotor inside. The rotor is driven by a rotary motor. A vacuum pump is connected to the upper end of the shell to form a vacuum chamber inside the shell. An alkaline inlet is provided at the top of the shell, an alkaline outlet is provided at the lower end of the shell, and a drain outlet is provided at the bottom of the shell. The rotary motor and the vacuum pump are respectively connected to the controller. Based on the monitoring data of the alkali solution flow meter, the controller adjusts the alkali solution circulation pump and the alkali solution flow regulating valve to regulate the alkali solution flow rate; based on the monitoring data of the temperature transmitter, the controller coordinates the adjustment of the heater and the cooling water flow regulating valve; based on the monitoring data of the pressure transmitter, the controller adjusts the oxygen outlet diaphragm regulating valve; and the controller adjusts the rectifier's current output. This includes: The controller is in communication with the rectifier of the electrolytic cell; A cooling water flow regulating valve, an alkali heat exchanger, an alkali circulating pump, a heater, and an alkali flow meter are sequentially installed along the pipeline facing the inlet side of the electrolytic cell, and are respectively connected to the controller. An alkaline solution flow regulating valve is installed between the alkaline solution circulating pump and the hydrogen separator, and is connected in communication with the controller; A temperature transmitter is installed between the electrolytic cell and the oxygen separator and is connected in communication with the controller. A pressure transmitter is installed between the oxygen separator and the oxygen-side scrubber and is connected in communication with the controller. An oxygen-hydrogen detection instrument and an oxygen outlet membrane regulating valve are installed at the outlet of the oxygen-side gas-water separator and are connected to the controller. A vacuum degassing device is installed at the bottom of the hydrogen separator where the alkaline outlet is located before the alkaline collection port of the oxygen separator. The vacuum degassing device includes a vertical shell with a rotor inside. The rotor is driven by a rotary motor. A vacuum pump is connected to the upper end of the shell to form a vacuum chamber inside the shell. An alkaline inlet is provided at the top of the shell, an alkaline outlet is provided at the lower end of the shell, and a drain outlet is provided at the bottom of the shell. The rotary motor and the vacuum pump are respectively connected to the controller. Based on the monitoring data of the alkali flow meter, the controller adjusts the alkali circulation pump and the alkali flow regulating valve to regulate the alkali flow rate; based on the monitoring data of the temperature transmitter, the controller coordinates the adjustment of the heater and the cooling water flow regulating valve; based on the monitoring data of the pressure transmitter, the controller adjusts the oxygen outlet diaphragm regulating valve; and the controller adjusts the current output of the rectifier.

[0011] Preferably, the rotor is a closed rotating cylinder, and the housing forms an annular chamber on the outside of the rotating cylinder. The vacuum pump is connected to the annular chamber. The bottom of the rotating cylinder is coaxially and fixedly connected to the output end of the rotating motor. The rotating motor is sealed to the housing. The alkali inlet is downward and connected to the inside of the rotating cylinder to introduce the alkali into the rotating cylinder. Multiple liquid ejection holes are spaced apart on the outer wall of the rotating cylinder to tear the liquid into micro-volume droplets or stretch it into an extremely thin liquid film under centrifugal force before it enters the annular chamber.

[0012] Preferably, the liquid ejection holes are spaced apart on the outer wall of the rotating cylinder, and the diameter of the liquid ejection holes gradually decreases from top to bottom along the axial direction of the rotating cylinder.

[0013] On the other hand, the present invention also provides an optimized control method for reducing the hydrogen content in oxygen in an alkaline water electrolysis hydrogen production system, comprising: Step S1: Set up an optimized control system for hydrogen production via water electrolysis, and determine the key process parameters affecting the hydrogen content of the alkaline water electrolysis hydrogen production system, including electrolysis current density, alkaline solution flow rate into the electrolyzer, electrolyzer temperature, and system pressure. Based on the hydrogen content in oxygen detected at the oxygen outlet, establish a model of the influence of the key process parameters of the alkaline water electrolysis hydrogen production system on the hydrogen content in oxygen. (1) Where: c HIO Hydrogen content in oxygen, in % (I) s Electrolysis current density, unit: A / m 2 T is the tank temperature in °C, p is the system pressure in MPa, and q is the alkali solution flow rate in m³ / s. 3 / h, D1 is a constant with a value range of 0~0.01, A1~A8 are the coefficients of hydrogen content in oxygen with respect to the temperature of the alkali tank, B1~B8 are the coefficients of hydrogen content in oxygen with respect to the system pressure, and C1~C8 are the coefficients of hydrogen content in oxygen with respect to the flow rate of the alkali solution. Step S2: Control the temperature of the alkali tank by maintaining constant current density, alkali flow rate, and system pressure, record the dynamic response data of hydrogen content in oxygen, and identify the values ​​of A1 to A8 in the model by using the nonlinear least squares solution method. The system controls the step change of pressure by maintaining constant current density, alkali flow rate, and alkali tank temperature, and records the dynamic response data of hydrogen content in oxygen. The values ​​of B1 to B8 in the model are identified by solving the nonlinear least squares method. By controlling the step change of alkali flow rate with constant current density, alkali tank temperature, and system pressure, and recording the dynamic response data of hydrogen content in oxygen, the values ​​of C1 to C8 in the model are identified by nonlinear least squares solution method. Step S3: Based on the influence model, with the goal of minimizing the hydrogen content in oxygen, the particle swarm optimization method is used to calculate the optimal control strategy of the hydrogen production system under different operating conditions, and the optimal control strategy is obtained after iteration. Step S4: Write the optimal control strategy data table into the controller. When the hydrogen production system is running under low load or fluctuating conditions, use the deviation between the measured temperature, pressure, and alkali flow data and the values ​​corresponding to the optimal control strategy to control the optimized control system to execute the control.

[0014] Preferably, the computation process using the particle swarm optimization algorithm is as follows: Step 1: Select the fitness function as the hydrogen content in oxygen, c. HIO (T, p, q), the optimization space is three-dimensional (T, p, q), the particle number is set to 500, the temperature T of the alkali tank is set to vary from [60, 95], the alkali flow rate q is set to vary from [40, 180], the system pressure p is set to vary from [1.6, 1.8], and the current density I is set to... s The position variation range is [0, 4000]. The rand function is used to randomly generate the initial velocity v and initial position x of each particle within the set position variation range. The fitness of each particle is calculated to obtain the individual optimal position m and the individual optimal value m. best And the global optimal position g and the global optimal value g best ; Step 2: Update the particle's velocity v and position x according to the following formula. (2) (3) Where: k is the current iteration number, K is the total number of iterations; c1 and c2 are learning factors, both set to 2; r1 and r2 are random numbers in [0, 1]; t is the running time of each particle step, set to 1; ω is the inertial weight of the velocity. max Take 0.9, ω min Take 0.4; Step 3: Calculate and update the fitness value of each particle again according to equation (1), and determine whether it is necessary to update the individual optimal position m and the individual optimal value m based on the fitness value. best And the global optimal position g and the global optimal value g best ; Step 4: Determine if k has reached the set number of iterations K. If it has, the iteration ends, and the optimization result m is output. best and g best Otherwise, proceed to Step 2.

[0015] Preferably, during the electrolytic hydrogen production process, the rotating drum is driven to rotate at high speed, drawing the liquid entering from the alkaline inlet into the inner side of the rotating drum. Under centrifugal force, the liquid is thrown out towards the liquid ejection port. In a vacuum environment, this promotes the release of dissolved gases in the alkaline solution. The rotational speed of the vacuum pump is calculated according to the following formula: (4) Where: v pump The speed of the vacuum pump is expressed in meters (m). 3 / h, R is the ideal gas constant, in J / (mol·K), T is the temperature of the alkaline solution, in K, M H2ρ is the molar mass of the gas, in kg / mol; P is the operating pressure of the vacuum pump, in Pa; k is the hydrogen content coefficient, ranging from 0.00125 to 0.00175.

[0016] Preferably, the internal volume of the rotating cylinder is V, in meters. 3 The internal height of the rotating cylinder is H (in meters), and the sum of the areas of all the liquid ejection holes is S. z The centrifugal pressure generated by the rotation of the rotating drum is P. c The unit is Pa. (5) (6) Where ρ is the density of the alkali solution, in kg / m³, W is the angular velocity of the rotating cylinder, in rad / s, and C... d This is the flow coefficient, with a value ranging from 0.6 to 0.9; Based on the total design area of ​​the liquid ejection hole and formulas (5) and (6), the rotational angular velocity W of the rotating cylinder is calculated, and the rotational angular velocity of the rotating cylinder driven by the rotating motor is controlled to be no less than the value of W.

[0017] The present invention includes at least the following beneficial effects: The optimized control system and method for the hydrogen content in oxygen in the alkaline water electrolysis hydrogen production system of the present invention, wherein the optimized control system is equipped with a cooling water flow regulating valve, an alkaline heat exchanger, an alkaline circulating pump, a heater, an alkaline flow meter, an alkaline flow regulating valve, a temperature transmitter, a pressure transmitter, an oxygen hydrogen detection instrument, an oxygen outlet membrane regulating valve, a vacuum degassing device, and a controller on the alkaline water electrolysis hydrogen production system. This system comprehensively regulates the key process parameters of the alkaline water electrolysis hydrogen production system, including current density, alkaline flow rate, tank temperature, and system pressure. Simultaneously, it collaboratively treats hydrogen bubbles dissolved in the alkaline circulating system, further significantly reducing the hydrogen content in the final output oxygen, thereby significantly improving the system's efficiency in reducing hydrogen content in oxygen, ensuring system safety while improving system performance.

[0018] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0019] Figure 1 A schematic diagram illustrating the workflow of the optimized control system for the alkaline water electrolysis hydrogen production system of the present invention; Figure 2 A schematic diagram of the optimized control system for the alkaline water electrolysis hydrogen production system of the present invention; Figure 3 This is a flowchart of the particle swarm optimization algorithm of the present invention; Figure 4This is a schematic diagram of the vacuum degassing device of the present invention; Instruction manual illustrations and reference numerals: 1. Oxygen outlet membrane regulating valve; 2. Oxygen-hydrogen detection instrument; 3. Oxygen-side gas-water separator; 4. Oxygen-side gas cooler; 5. Oxygen-side scrubber; 6. Pressure transmitter; 7. Oxygen separator; 8. Temperature transmitter; 9. Electrolytic cell; 10. Alkali flow meter; 11. Heater; 12. Alkali circulation pump; 13. Heat exchanger; 14. Cooling water flow regulating valve; 15. Hydrogen separator; 16. Hydrogen-side gas-water separator; 17. Hydrogen-side scrubber; 18. Hydrogen-side gas cooler; 19. Alkali flow regulating valve; 20. Vacuum degassing device; 21. Rotary motor; 22. Vacuum pump; 23. Vacuum port; 24. Alkali inlet; 25. Alkali outlet; 26. Drainage port. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0021] It should be noted that, unless otherwise specified, the experimental methods described in the following embodiments are all conventional methods, and the reagents and materials described are all commercially available unless otherwise specified. In the description of this invention, the terms "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0022] like Figure 1-4 As shown, this invention provides an optimized control system for reducing the hydrogen content in the oxygen of an alkaline water electrolysis hydrogen production system. The system is installed on the water electrolysis hydrogen production system, which includes an electrolyzer 9, an oxygen separator 7 connected to the oxygen outlet of the electrolyzer 9, an oxygen-side scrubber 5, an oxygen-side gas cooler 4, an oxygen-side gas-water separator 3, and a hydrogen separator 15, a hydrogen-side scrubber 17, a hydrogen-side gas cooler 18, and a hydrogen-side gas-water separator 16 connected to the hydrogen outlet of the electrolyzer 9. The controller is in communication with the rectifier connected to the electrolytic cell 9; A cooling water flow regulating valve 14, an alkali heat exchanger 13, an alkali circulation pump 12, a heater 11, and an alkali flow meter 10 are sequentially arranged along the pipeline facing the inlet side of the electrolytic cell 9, and the cooling water flow regulating valve 14, the alkali circulation pump 12, the heater 11, and the alkali flow meter 10 are respectively connected to the controller for communication. An alkaline flow regulating valve 19 is installed between the alkaline circulating pump 12 and the hydrogen separator 15 and is connected in communication with the controller. A temperature transmitter 8 is installed between the electrolytic cell 9 and the oxygen separator 7 and is connected in communication with the controller. A pressure transmitter 6 is installed between the oxygen separator 7 and the oxygen-side scrubber 5 and is connected in communication with the controller. An oxygen-hydrogen detection instrument 2 and an oxygen outlet membrane regulating valve 1 are installed at the outlet of the oxygen-side gas-water separator 3 and are connected to the controller. A vacuum degassing device 20 is installed at the bottom of the hydrogen separator 15, where the alkaline outlet 25 is located, and at the front end of the alkaline collection port of the oxygen separator 7. The vacuum degassing device 20 includes a vertical housing, inside which a rotor is installed. The rotor is driven by a rotary motor 21. A vacuum port is provided at the upper end of the housing, which is connected to a vacuum pump 22 to form a vacuum chamber inside the housing. An alkaline inlet 24 is provided at the top of the housing, an alkaline outlet 25 is provided at the lower end of the housing, and a drain port 26 is provided at the bottom of the housing. The rotary motor 21 and the vacuum pump 22 are respectively connected to the controller. The optimized control system includes a cooling water flow regulating valve 14, an alkali heat exchanger 13, an alkali circulating pump 12, a heater 11, an alkali flow meter 10, an alkali flow regulating valve 19, a temperature transmitter 8, a pressure transmitter 6, an oxygen hydrogen detection instrument 2, an oxygen outlet diaphragm regulating valve 1, a vacuum degassing device 20, and a controller. The controllable mechanism of the vacuum degassing device 20 includes a rotary motor 21 and a vacuum pump 22.

[0023] The flow rate of alkali solution entering the electrolytic cell 9 is calculated based on the actual load of the electrolytic cell 9. According to the monitoring data of the alkali solution flow meter 10, the alkali solution circulation pump 12 and the alkali solution flow regulating valve 19 are adjusted by the controller to achieve the adjustment of the alkali solution flow rate. The output frequency of the motor is adjusted by the frequency converter to quickly control the output flow rate of the alkali solution circulation pump 12 within the required range, and then the precise adjustment is achieved by changing the opening degree of the regulating valve.

[0024] Based on the monitoring data from the temperature transmitter 8, the controller coordinates the adjustment of the heater 11 and the opening of the cooling water flow regulating valve 14. When the temperature of the alkali tank is low, the component heater 11 is turned on.

[0025] When the temperature of the alkali tank is high, open the component cooling water flow regulating valve 14.

[0026] Based on the monitoring data from pressure transmitter 6, the opening degree of oxygen outlet diaphragm regulating valve 1 is adjusted by the controller.

[0027] The current output of the rectifier is adjusted by the controller, and the electrolytic current density is adjusted to the optimal current density through communication between the controller and the rectifier.

[0028] The gas generated at the anode and cathode of electrolytic cell 9 flows into the separator along with the alkali solution. The gas exists in the form of small bubbles. It stays in the separator for a certain period of time to achieve separation of the bubbles and the alkali solution. However, many small bubbles cannot leave the alkali solution within this process time. A certain amount of hydrogen bubbles will dissolve in the alkali solution on the hydrogen side. As the alkali solution flows into the oxygen side, the hydrogen content in the oxygen will eventually increase. Therefore, this embodiment is equipped with a vacuum degassing device 20 and a centrifugal separator is set in the vacuum degassing device 20. For the alkali solution flow rate during stable operation, the speed of the rotary motor 21 is controlled by the controller to control the centrifugal speed and disperse the alkali solution. In a vacuum environment, the hydrogen inside the small volume liquid is more easily removed, ensuring that the hydrogen in the circulating alkali solution is basically completely removed.

[0029] This system combines high-precision sensor data to comprehensively regulate key process parameters such as current density, alkali flow rate, tank temperature, and system pressure during the operation of the alkaline water electrolysis hydrogen production system. It also optimizes and controls the purity of electrolysis products, gas separation, and alkali circulation, significantly reducing the hydrogen content in oxygen and improving system performance while ensuring system safety.

[0030] In another technical solution, such as Figure 1-4 As shown, the rotor is a closed rotating cylinder, and the housing forms an annular chamber on the outside of the rotating cylinder. The vacuum pump 22 is connected to the annular chamber. The bottom of the rotating cylinder is coaxially and fixedly connected to the output end of the rotating motor 21. The rotating motor 21 is sealed to the housing. The alkali inlet 24 is connected downward to the inside of the rotating cylinder to introduce alkali into the rotating cylinder. Multiple liquid ejection holes are spaced apart on the outer wall of the rotating cylinder to tear the liquid into micro-volume droplets or stretch it into an extremely thin liquid film under centrifugal force before it enters the annular chamber.

[0031] A hollow shaft is connected to the top center of the rotating cylinder, extending upwards through the shell and with its upper opening serving as the alkali inlet 24 to introduce alkali into the rotating cylinder. The hollow shaft is sealed to the shell, and its lower end is rotatably connected to the rotating cylinder via a bearing. A vacuum pump 22 is connected to the outside of the rotating cylinder. Multiple liquid ejection holes are spaced apart on the outer wall of the rotating cylinder. Under centrifugal force, when the liquid is thrown out of the rotating cylinder, it is torn into micro-volume droplets or stretched into an extremely thin liquid film.

[0032] The entire rotor is sealed within a vacuum chamber, which is maintained at a very low total pressure (high vacuum) by a vacuum pump. According to Henry's Law, the low partial pressure environment provides a powerful driving force for the escape of dissolved gases. The tiny droplets / films pulverized by centrifugal force have every surface fully exposed in this highly efficient vacuum environment, allowing the dissolved gases to be released instantaneously and violently.

[0033] In another technical solution, such as Figure 1-4 As shown, the liquid ejection holes are spaced apart on the outer wall of the rotating cylinder, that is, they are distributed spaced apart circumferentially and axially. The diameter of the liquid ejection holes gradually decreases from top to bottom along the axial direction of the rotating cylinder. When the alkali liquid is relatively large, the gravity factor can be considered, and the size and distribution of the liquid ejection holes on the rotating cylinder can be simulated to further optimize the liquid separation effect at different heights of the rotating separation.

[0034] This invention also provides an optimized control method for the hydrogen content in oxygen in an alkaline water electrolysis hydrogen production system, comprising: Step S1: Set up an optimized control system for hydrogen production via water electrolysis, and determine the key process parameters affecting the hydrogen content of the alkaline water electrolysis hydrogen production system, including the electrolysis current density, the flow rate of the alkaline solution entering the electrolyzer 9, the temperature of the electrolyzer 9, and the system pressure. Based on the hydrogen content in the oxygen detected at the oxygen outlet, establish a model of the influence of the key process parameters of the alkaline water electrolysis hydrogen production system on the hydrogen content in the oxygen. (1) Where: c HIO Hydrogen content in oxygen, in % (I) s Electrolysis current density, unit: A / m 2 T is the tank temperature in °C, p is the system pressure in MPa, and q is the alkali solution flow rate in m³ / s. 3 / h, D1 is a constant with a value range of 0~0.01, A1~A8 are the coefficients of hydrogen content in oxygen with respect to the temperature of the alkali tank, B1~B8 are the coefficients of hydrogen content in oxygen with respect to the system pressure, and C1~C8 are the coefficients of hydrogen content in oxygen with respect to the flow rate of the alkali solution. Step S2: Control the temperature of the alkali tank by maintaining constant current density, alkali flow rate, and system pressure, record the dynamic response data of hydrogen content in oxygen, and identify the values ​​of A1 to A8 in the model by using the nonlinear least squares solution method. The system controls the step change of pressure by maintaining constant current density, alkali flow rate, and alkali tank temperature, and records the dynamic response data of hydrogen content in oxygen. The values ​​of B1 to B8 in the model are identified by solving the nonlinear least squares method. By controlling the step change of alkali flow rate with constant current density, alkali tank temperature, and system pressure, and recording the dynamic response data of hydrogen content in oxygen, the values ​​of C1 to C8 in the model are identified by nonlinear least squares solution method. Step S3: Based on the influence model, with the goal of minimizing the hydrogen content in oxygen, the particle swarm optimization method is used to calculate the optimal control strategy of the hydrogen production system under different operating conditions, and the optimal control strategy is obtained after iteration. Step S4: Write the optimal control strategy data table into the controller. When the hydrogen production system is running under low load or fluctuating conditions, use the deviation between the measured temperature, pressure, and alkali flow data and the values ​​corresponding to the optimal control strategy to control the optimized control system to execute the control.

[0035] For the overall operation of the system, considering the process parameters throughout the system, the influence of process operating conditions such as system pressure, alkali tank temperature, and alkali flow rate on the hydrogen content in oxygen is taken into account. The model method is used to provide an optimized control strategy for the hydrogen production system to operate under low load or fluctuating conditions. Based on the optimized control strategy, an optimized control method is proposed to improve the safety of the hydrogen production system.

[0036] In another technical solution, such as Figure 1-4 As shown, the computational process using the particle swarm optimization algorithm is as follows: Step 1: Select the fitness function as the hydrogen content in oxygen, c. HIO (T, p, q), the optimization space is three-dimensional (T, p, q), the particle number is set to 500, the temperature T of the alkali tank is set to vary from [60, 95], the alkali flow rate q is set to vary from [40, 180], the system pressure p is set to vary from [1.6, 1.8], and the current density I is set to... s The position variation range is [0, 4000]. The rand function is used to randomly generate the initial velocity v and initial position x of each particle within the set position variation range. The fitness of each particle is calculated to obtain the individual optimal position m and the individual optimal value m. best And the global optimal position g and the global optimal value g best ; Step 2: Update the particle's velocity v and position x according to the following formula. (2) (3) Where: k is the current iteration number, K is the total number of iterations; c1 and c2 are learning factors, both set to 2; r1 and r2 are random numbers in [0, 1]; t is the running time of each particle step, set to 1; ω is the inertial weight of the velocity. max Take 0.9, ω min Take 0.4; Step 3: Calculate and update the fitness value of each particle again according to equation (1), and determine whether it is necessary to update the individual optimal position m and the individual optimal value m based on the fitness value. best And the global optimal position g and the global optimal value g best ; Step 4: Determine if k has reached the set number of iterations K. If it has, the iteration ends, and the optimization result m is output. best and gbest Otherwise, proceed to Step 2.

[0037] The particle swarm optimization algorithm is used to adapt and optimize the relationship weights of key process parameters. The iteration is generally set to K=500. After reaching the number of iterations, the corresponding control parameter data values ​​of the optimal strategy are output.

[0038] In another technical solution, such as Figure 1-4 As shown, during the electrolytic hydrogen production process, the rotating drum is driven to rotate at high speed, drawing the liquid entering from the alkaline inlet 24 into the inner side of the rotating drum. Under centrifugal force, the liquid is thrown out towards the liquid ejection port. In a vacuum environment, this promotes the release of dissolved gases in the alkaline solution. The rotational speed of the vacuum pump 22 is calculated according to the following formula: (4) Where: v pump The speed of the vacuum pump is 22 m / s. 3 / h, R is the ideal gas constant, in J / (mol·K), T is the temperature of the alkaline solution, in K, M H2 ρ is the molar mass of the gas, in kg / mol; P is the operating pressure of the vacuum pump, in Pa; k is the hydrogen content coefficient, ranging from 0.00125 to 0.00175.

[0039] The flow rate of alkali solution entering electrolyzer 9 is calculated based on the actual load of electrolyzer 9. The output flow rate of the alkali solution circulating pump 12 is quickly controlled within the required range by adjusting the motor output frequency using a frequency converter. Precise adjustment is then achieved by varying the opening of the regulating valve to ensure that the flow rate of alkali solution entering electrolyzer 9 remains close to the actual calculated value, thus reducing the oxygen content in the hydrogen. A high-speed rotating vacuum degassing device 20 is added between the alkali solution outlet 25 at the bottom of the hydrogen separator 15 and the alkali solution collection port of the separator. This device releases trace amounts of dissolved hydrogen in the alkali solution, reducing the hydrogen content in the circulating alkali solution, thereby reducing the hydrogen carried out by the oxygen-side alkali solution and lowering the hydrogen content in the oxygen. Thus, the optimization of hydrogen content in oxygen by controlling system pressure, alkali tank temperature, alkali solution flow rate, and current density accounts for approximately 65%, while the optimization by the vacuum degassing device 20 accounts for approximately 35%.

[0040] In another technical solution, such as Figure 1-4 As shown, the internal volume of the rotating cylinder is V, in meters. 3 The internal height of the rotating cylinder is H (in meters), and the sum of the areas of all the liquid ejection holes is S. z The centrifugal pressure generated by the rotation of the rotating drum is P. c The unit is Pa. (5) (6) Where ρ is the density of the alkali solution, in kg / m³, W is the angular velocity of the rotating cylinder, in rad / s, and C... d This is the flow coefficient, with a value ranging from 0.6 to 0.9; Based on the total design area of ​​the liquid ejection hole and formulas (5) and (6), the rotational angular velocity W of the rotating cylinder is calculated, and the rotational angular velocity of the rotating cylinder driven by the rotating motor is controlled to be no less than the value of W.

[0041] C d C is a dimensionless number, typically ranging from 0.6 to 0.9. For a thin-walled, sharp-edged circular orifice, C... d Typical values ​​are approximately 0.6-0.65, primarily driven by streamlined contraction effects. For orifices with rounded flared openings or streamlined nozzles, this reduces contraction and friction. d The value should be close to or even exceed 0.9. If the effect of gravity on the pore distribution is considered, setting a larger diameter for the top pores can significantly reduce the required pore area and improve separation efficiency through vacuuming. The vacuum parameter P should be as low as possible, and the pumping rate should meet the gas inflow rate.

[0042] The following are specific examples: Comparative Example 1: The alkaline water electrolysis hydrogen production system uses an electrolyzer with a hydrogen production capacity of 1000 Nm³ / h, a current density of approximately 3000 A / m², an operating temperature of 90℃, a pressure of 1.6 MPa, approximately 280 chambers, and a total power of 5.01 MW. It includes a hydrogen separator, an oxygen separator, and pressure balance with the electrolyzer. The alkaline solution flow rate is 75 m³ / h. 3 / h, the height of the rotating cylinder is 0.83m and the volume is 0.104m³. 3 The total area of ​​the liquid ejection holes is 104 cm². 2 The rotating drum rotates at 2100 rpm, the vacuum pump rotates at 1500 rpm, and the operating pressure of the vacuum pump is 10 kPa. After the system is running stably, the oxygen hydrogen detector measures a real-time oxygen hydrogen (HTO) concentration percentage of 0.7%.

[0043] Example 1: Using the same alkaline water electrolysis hydrogen production system electrolyzer and parameters as Comparative Example 1, an optimized control system for the hydrogen content in oxygen in the alkaline water electrolysis hydrogen production system was set up, but the vacuum pump and rotary motor were not turned on. Only the process parameters were regulated using the control method of this invention. After the system was running stably, the hydrogen concentration percentage in oxygen (HTO) measured by the oxygen hydrogen detection instrument was 0.5% in real time.

[0044] Example 2: Using the same alkaline water electrolysis hydrogen production system electrolyzer and parameters as Comparative Example 1, an optimized control system for the hydrogen content in oxygen in the alkaline water electrolysis hydrogen production system was set up. However, only the vacuum pump and rotary motor were turned on to eliminate hydrogen from the circulating alkaline solution. The process parameters were not regulated using the control method of this invention. After the system was running stably, the oxygen hydrogen detection instrument measured the real-time oxygen hydrogen (HTO) concentration percentage to be 0.6%.

[0045] Example 3: Using the same alkaline water electrolysis hydrogen production system electrolyzer and parameters as Comparative Example 1, a complete optimized control system for the hydrogen content in oxygen in the alkaline water electrolysis hydrogen production system was set up. After the system was running stably, the hydrogen concentration in oxygen (HTO) measured by the oxygen hydrogen detection instrument was 0.35% in real time.

[0046] In summary, the optimized control system and method for hydrogen content in oxygen in the alkaline water electrolysis hydrogen production system of the present invention includes a cooling water flow regulating valve, an alkaline heat exchanger, an alkaline circulating pump, a heater, an alkaline flow meter, an alkaline flow regulating valve, a temperature transmitter, a pressure transmitter, an oxygen hydrogen detection instrument, an oxygen outlet membrane regulating valve, a vacuum degassing device, and a controller. This system comprehensively regulates key process parameters such as current density, alkaline flow rate, tank temperature, and system pressure during the operation of the alkaline water electrolysis hydrogen production system. Simultaneously, it collaboratively handles hydrogen bubbles dissolved in the alkaline circulating system, further significantly reducing the hydrogen content in the final output oxygen. This substantially improves the system's efficiency in reducing hydrogen content in oxygen, ensuring system safety while enhancing system performance.

[0047] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. An optimized control system for the hydrogen content in oxygen in an alkaline water electrolysis hydrogen production system, wherein the system is installed on the water electrolysis hydrogen production system, the water electrolysis hydrogen production system comprising an electrolyzer, an oxygen separator connected to the oxygen outlet of the electrolyzer, an oxygen-side scrubber, an oxygen-side gas cooler, an oxygen-side gas-water separator, and a hydrogen separator, a hydrogen-side scrubber, a hydrogen-side gas cooler, and a hydrogen-side gas-water separator connected to the hydrogen outlet of the electrolyzer, characterized in that, include: The controller is in communication with the rectifier connected to the electrolytic cell; A cooling water flow regulating valve, an alkali heat exchanger, an alkali circulating pump, a heater, and an alkali flow meter are sequentially installed along the pipeline facing the inlet side of the electrolytic cell, and the cooling water flow regulating valve, the alkali circulating pump, the heater, and the alkali flow meter are respectively connected to the controller for communication. An alkaline solution flow regulating valve is installed between the alkaline solution circulating pump and the hydrogen separator, and is connected in communication with the controller; A temperature transmitter is installed between the electrolytic cell and the oxygen separator and is connected in communication with the controller; A pressure transmitter is installed between the oxygen separator and the oxygen-side scrubber and is connected in communication with the controller. An oxygen-hydrogen detection instrument and an oxygen outlet membrane regulating valve are installed at the outlet of the oxygen-side gas-water separator and are connected to the controller. A vacuum degassing device is installed at the bottom of the hydrogen separator where the alkaline outlet is located before the alkaline collection port of the oxygen separator. The vacuum degassing device includes a vertical shell with a rotor inside. The rotor is driven by a rotary motor. A vacuum pump is connected to the upper end of the shell to form a vacuum chamber inside the shell. An alkaline inlet is provided at the top of the shell, an alkaline outlet is provided at the lower end of the shell, and a drain outlet is provided at the bottom of the shell. The rotary motor and the vacuum pump are respectively connected to the controller. Based on the monitoring data of the alkali flow meter, the controller adjusts the alkali circulation pump and the alkali flow regulating valve to regulate the alkali flow rate; based on the monitoring data of the temperature transmitter, the controller coordinates the adjustment of the heater and the cooling water flow regulating valve; based on the monitoring data of the pressure transmitter, the controller adjusts the oxygen outlet diaphragm regulating valve; and the controller adjusts the current output of the rectifier.

2. The optimized control system for hydrogen content in oxygen in the alkaline water electrolysis hydrogen production system as described in claim 1, characterized in that, The rotor is a closed rotating cylinder. The housing forms an annular chamber on the outside of the rotating cylinder. The vacuum pump is connected to the annular chamber. The bottom of the rotating cylinder is coaxially and fixedly connected to the output end of the rotating motor. The rotating motor is sealed to the housing. The alkali inlet is downward and connected to the inside of the rotating cylinder to introduce the alkali into the rotating cylinder. Multiple liquid ejection holes are spaced apart on the outer wall of the rotating cylinder to tear the liquid into micro-volume droplets or stretch it into an extremely thin liquid film under centrifugal force before it enters the annular chamber.

3. The optimized control system for hydrogen content in oxygen in the alkaline water electrolysis hydrogen production system as described in claim 2, characterized in that, The liquid ejection holes are spaced apart on the outer wall of the rotating cylinder, and the diameter of the liquid ejection holes gradually decreases from top to bottom along the axial direction of the rotating cylinder.

4. The optimized control method for the optimized control system of hydrogen content in oxygen in the alkaline water electrolysis hydrogen production system as described in claim 2, characterized in that, include: Step S1: Set up an optimized control system for hydrogen production via water electrolysis, and determine the key process parameters affecting the hydrogen content of the alkaline water electrolysis hydrogen production system, including electrolysis current density, alkaline solution flow rate into the electrolyzer, electrolyzer temperature, and system pressure. Based on the hydrogen content in oxygen detected at the oxygen outlet, establish a model of the influence of the key process parameters of the alkaline water electrolysis hydrogen production system on the hydrogen content in oxygen. （1） Where: c HIO Hydrogen content in oxygen, in % (I) s Electrolysis current density, unit: A / m 2 T is the tank temperature in °C, p is the system pressure in MPa, and q is the alkali solution flow rate in m³ / s. 3 / h, D1 is a constant with a value range of 0~0.01, A1~A8 are the coefficients of hydrogen content in oxygen with respect to the temperature of the alkali tank, B1~B8 are the coefficients of hydrogen content in oxygen with respect to the system pressure, and C1~C8 are the coefficients of hydrogen content in oxygen with respect to the flow rate of the alkali solution. Step S2: Maintain constant current density, alkali flow rate, and system pressure; control the temperature step change in the alkali tank; record the dynamic response data of hydrogen content in oxygen; and identify the relevant parameters in the model using the nonlinear least squares method. The value; By controlling the step changes in system pressure under constant current density, alkali flow rate, and alkali tank temperature, and recording the dynamic response data of hydrogen content in oxygen, the model is identified using a nonlinear least squares solution method. The value; By controlling the step changes in alkali solution flow rate under constant current density, alkali tank temperature, and system pressure, and recording the dynamic response data of hydrogen content in oxygen, the model is identified using a nonlinear least squares method. The value; Step S3: Based on the influence model, with the goal of minimizing the hydrogen content in oxygen, the particle swarm optimization method is used to calculate the optimal control strategy of the hydrogen production system under different operating conditions, and the optimal control strategy is obtained after iteration. Step S4: Write the optimal control strategy data table into the controller. When the hydrogen production system is running under low load or fluctuating conditions, use the deviation between the measured temperature, pressure, and alkali flow data and the values ​​corresponding to the optimal control strategy to control the optimized control system to execute the control.

5. The method for optimizing and controlling the hydrogen content in oxygen in an alkaline water electrolysis hydrogen production system as described in claim 4, characterized in that, The computational process using the particle swarm optimization algorithm is as follows: Step 1: Select the fitness function as the hydrogen content in oxygen, c. HIO (T, p, q), the optimization space is three-dimensional (T, p, q), the particle number is set to 500, the temperature T of the alkali tank is set to vary from [60, 95], the alkali flow rate q is set to vary from [40, 180], the system pressure p is set to vary from [1.6, 1.8], and the current density I is set to... s The position variation range is [0, 4000]. The rand function is used to randomly generate the initial velocity v and initial position x of each particle within the set position variation range. The fitness of each particle is calculated to obtain the individual optimal position m and the individual optimal value m. best And the global optimal position g and the global optimal value g best ; Step 2: Update the particle's velocity v and position x according to the following formula. （2） （3） Where: k is the current iteration number, K is the total number of iterations; c1 and c2 are learning factors, both set to 2; r1 and r2 are random numbers in [0, 1]; t is the running time of each particle step, set to 1; ω is the inertial weight of the velocity. max Take 0.9, ω min Take 0.4; Step 3: Calculate and update the fitness value of each particle again according to equation (1), and determine whether it is necessary to update the individual optimal position m and the individual optimal value m based on the fitness value. best And the global optimal position g and the global optimal value g best ; Step 4: Determine if k has reached the set number of iterations K. If it has, the iteration ends, and the optimization result m is output. best and g best Otherwise, proceed to Step 2.

6. The method for optimizing and controlling the hydrogen content in oxygen in an alkaline water electrolysis hydrogen production system as described in claim 4, characterized in that, In the electrolytic hydrogen production process, a high-speed rotating drum is driven to draw liquid from the alkaline inlet into the inner side of the drum. Under centrifugal force, the liquid is thrown out towards the ejection port. In a vacuum environment, this promotes the release of dissolved gases in the alkaline solution. The speed of the vacuum pump is calculated according to the following formula: （4） Where: v pump The speed of the vacuum pump is expressed in meters (m). 3 / h, R is the ideal gas constant, in J / (mol·K), T is the temperature of the alkaline solution, in K, M H2 ρ is the molar mass of the gas, in kg / mol; P is the operating pressure of the vacuum pump, in Pa; k is the hydrogen content coefficient, ranging from 0.00125 to 0.00175.

7. The method for optimizing and controlling the hydrogen content in oxygen in an alkaline water electrolysis hydrogen production system as described in claim 4, characterized in that, The internal volume of the rotating cylinder is V, in meters. 3 The internal height of the rotating cylinder is H (in meters), and the sum of the areas of all the liquid ejection holes is... The centrifugal pressure generated by the rotation of the rotating drum is P. c The unit is Pa. （5） （6） Where ρ is the density of the alkali solution, in kg / m³, W is the angular velocity of the rotating cylinder, in rad / s, and C... d This is the flow coefficient, with a value ranging from 0.6 to 0.9; Based on the total design area of ​​the liquid ejection hole and formulas (5) and (6), the rotational angular velocity W of the rotating cylinder is calculated, and the rotational angular velocity of the rotating cylinder driven by the rotating motor is controlled to be no less than the value of W.

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