Method and system for linkage control of concentration and temperature of alkali liquor

Abstract

The embodiment of the invention provides an alkali liquor concentration and temperature linkage control method and system, and belongs to the technical field of hydrogen production through alkaline electrolysis of water. The method comprises the following steps: acquiring working current of an electrolytic cell; the water consumption mass of water electrolysis is calculated according to the working current of the electrolytic cell, and the alkali liquor concentration change adjusting time is obtained; the pH value is detected according to the alkali liquor concentration change adjusting time, and the current pH value is obtained; regulating and controlling the current PH value to be within a PH preset target range according to the deionized water supplement amount information and the concentrated alkali supplement amount information to obtain alkali liquor concentration control information; monitoring the alkali liquor temperature according to the alkali liquor concentration control information to obtain a current temperature value; according to the cooling water inflow information and the heating duty ratio information, the current temperature value is regulated and controlled to be within the temperature preset target range, and alkali liquor temperature control information is obtained. The running state of the electrolytic cell can be fully automatically controlled and dynamically adjusted, manual field operation is reduced to the maximum extent, and the safety risk is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrogen production by alkaline electrolysis of water, and particularly relates to a method and system for linkage control of alkali concentration and temperature. BACKGROUND

[0002] In the past two years, the development of AEM electrolytic cells has attracted more and more attention from the hydrogen energy market. Compared with alkaline electrolytic cells (ALKEC), anion exchange membrane electrolytic cells (AEMEC) have better performance and faster start-stop. Compared with proton exchange membrane electrolytic cells (PEMEC), AEMEC has obvious price advantage and has become a highly potential route for hydrogen production by water electrolysis. At present, the development of hydrogen production systems specially used for AEM electrolytic cells is still in the initial stage, and most of them follow the scheme of ALK hydrogen production system. However, there are great differences between AEM electrolytic cells and ALK electrolytic cells in terms of liquid inlet mode, alkali concentration, gas-liquid separation and purification requirements, output pressure and the like. Directly using the ALK system scheme is obviously not applicable, and therefore it is necessary to customize the design of the hydrogen production system for AEM electrolytic cells.

[0003] Among them, the two factors that have the greatest impact on the operation state of the electrolytic cell are the alkali concentration and the temperature. At present, the AEM electrolytic cell has low efficiency in electrolyzing pure water and large power consumption, and usually uses 0.1-1M KOH as the electrolyte to increase the ion conductivity and reduce the energy consumption. With the electrolysis reaction, the water in the solution will be continuously consumed, and the alkali concentration will continuously increase. The high concentration is not conducive to the mass transfer and heat dissipation of the AEM electrolytic cell. At the same time, under long-term operation, the KOH solute may be reduced due to gas escape or electrode corrosion, etc., resulting in a decrease in concentration and affecting the electrolysis efficiency. It is very important to maintain the stability of the alkali concentration for the efficient operation of the electrolytic cell. At the same time, when the alkali concentration is adjusted, the temperature will be affected to a certain extent. The higher the temperature, the higher the electrolysis performance. The water or alkali supplement process will cause temperature fluctuations, and the synchronous control of temperature changes is also very important for the efficient operation of the electrolytic cell.

[0004] In combination with the related technologies, the hydrogen production system for AEM water electrolysis hydrogen production has the following deficiencies in concentration and temperature control:

[0005] 1. Usually, the liquid level is used as the basis for judging water supplement. When the alkali liquid level is lower than the critical value, water supplement is started. Since the KOH solute in the electrolytic cell may exist in the form of escape, this method cannot accurately determine the actual alkali concentration in time, and the optimal water supplement or alkali supplement time cannot be determined.

[0006] 2. The alkali temperature is usually directly considered as equal to the water tank temperature, and is not dynamically adjusted in real time, and cannot be matched with the optimal operation state of the electrolytic cell.

[0007] 3. There is no scheme for linkage control of alkali concentration and temperature, and the stable and optimal working condition for the operation of the electrolytic cell cannot be completely provided.

[0008] 4. The traditional alkaline electrolytic tank needs manual operation for alkali or water supplement, which has great safety risk.

[0009] Therefore, the technical problems in the related art need to be improved. SUMMARY

[0010] The main purpose of the embodiments of the present application is to provide a method and system for linkage control of alkali concentration and temperature, which can linkage control of alkali concentration and temperature, and automatically control the dynamic adjustment of the running state of the electrolytic tank.

[0011] To achieve the above purpose, one aspect of the embodiments of the present application provides a method for linkage control of alkali concentration and temperature, which comprises the following steps:

[0012] Obtaining the working current of the electrolytic tank;

[0013] Calculating the water consumption quality of water electrolysis according to the working current of the electrolytic tank, and obtaining the alkali concentration change adjustment time;

[0014] Detecting the PH value according to the alkali concentration change adjustment time to obtain the current PH value;

[0015] Comparing the current PH value with the preset target PH value to obtain deionized water supplement information and concentrated alkali supplement information;

[0016] Regulating the current PH value into the preset target PH range according to the deionized water supplement information and the concentrated alkali supplement information to obtain alkali concentration control information;

[0017] Monitoring the alkali temperature according to the alkali concentration control information to obtain the current temperature value;

[0018] Comparing the current temperature value with the preset target temperature value to obtain cooling water inflow information and heating duty cycle information;

[0019] Regulating the current temperature value into the preset target temperature range according to the cooling water inflow information and the heating duty cycle information to obtain alkali temperature control information.

[0020] In some embodiments, the calculating the water consumption quality of water electrolysis according to the working current of the electrolytic tank to obtain the alkali concentration change adjustment time comprises:

[0021] Using the working current of the electrolytic tank to calculate the water consumption quality of water electrolysis to obtain the water consumption quality, and the used formula comprises:

[0022]

[0023] wherein I is the working current of the electrolytic cell, t' is the working time, Mw is the molar mass of water, F is the Faraday constant, Mw is the molar mass of water, F is the Faraday constant,

[0024] The concentration of the lye is increased to 1.1M as a time node;

[0025] The time required when the concentration is increased to 1.1M is calculated according to the time node and the water consumption mass, to obtain the lye concentration change adjustment time, and the formula used includes:

[0026]

[0027] wherein m is the initial lye mass, t is the lye concentration change adjustment time when the concentration is increased to 1.1M.

[0028] In some embodiments, the comparison of the current PH value with the preset target PH value, obtaining the deionized water supplement amount information and the concentrated lye supplement amount information, includes:

[0029] The current PH value is compared with the preset target PH value, and if the target PH value is less than the current PH value, the deionized water supplement amount is calculated to obtain the deionized water supplement amount information.

[0030] If the target PH value is greater than the current PH value, the concentrated lye supplement amount is calculated to obtain the concentrated lye supplement amount information.

[0031] In some embodiments, if the target PH value is greater than the current PH value, the concentrated lye supplement amount is calculated to obtain the concentrated lye supplement amount information, and the formula used includes:

[0032]

[0033] wherein, M is the initial target lye concentration, i.e. 1M; is the lye concentration at time t; is the concentration of the supplemented lye, V2 is the volume of the lye in the storage tank at time t, V 浓碱 is the concentrated lye supplement amount information.

[0034] In some embodiments, the current PH value is regulated to the preset target PH range according to the deionized water supplement amount information and the concentrated lye supplement amount information, to obtain lye concentration control information, including:

[0035] The current PH value is regulated to the target PH value ± 5% range and lasts for more than 10 minutes according to the deionized water supplement amount information and the concentrated lye supplement amount information, to obtain lye concentration control information.

[0036] In some embodiments, the comparison of the current temperature value with the preset target temperature value, obtaining cooling water inflow information and heating duty cycle information, comprises:

[0037] The comparison of the current temperature value with the preset target temperature value, when the current temperature value is higher than the target temperature value, calculating cooling water inflow information, and cooling by adjusting cooling water flow;

[0038] When the current temperature value is lower than the target temperature value, calculate the heating duty cycle information, and heat by controlling the heating rod duty cycle.

[0039] In some embodiments, when the current temperature value is lower than the target temperature value, the heating duty cycle information is calculated, and the heating rod duty cycle is controlled to heat, the formula used comprises:

[0040] DC 加热 = K p e(t) + K i ∫0 t e(t)dt

[0041] Wherein, K p is the proportional coefficient, K i is the integral coefficient, e(t) is the temperature difference at the moment, DC 加热 is the heating duty cycle information.

[0042] In some embodiments, the current temperature value is regulated to the temperature preset target range according to the cooling water inflow information and the heating duty cycle information, and the lye temperature control information is obtained, comprising:

[0043] According to the cooling water inflow information and the heating duty cycle information, the current temperature value is regulated to be within the target temperature value ± 0.5℃ range and lasts for more than 5 minutes, and the lye temperature control information is obtained.

[0044] To achieve the above purpose, another aspect of the embodiment of the present application proposes a system for lye concentration and temperature linkage control, which is used to realize the method for lye concentration and temperature linkage control as described above. The system comprises a liquid storage tank, a deionized water tank, a first proportional valve, a concentrated lye tank, a flow pump, a heat exchanger, a second proportional valve, a cooling water tower, an electric pump, and an electrolytic cell.

[0045] The liquid storage tank is provided with a heating rod, a stirring device, a liquid level meter, a pH sensor, and a first temperature sensor.

[0046] The heating rod is used to regulate the temperature of the alkali solution; the stirring device is used to stir the alkali solution in the tank; the level gauge is used to monitor the volume of the alkali solution and assist in calculating the amount of water to be added; the pH sensor is used to detect the pH value of the alkali solution; the first temperature sensor is used to monitor the temperature of the alkali solution in the storage tank.

[0047] The deionized water tank is used to store deionized water and dilute alkaline solution.

[0048] The deionized water tank and the storage tank are connected by the first proportional valve;

[0049] The concentrated alkali tank is used to store alkali solution and replenish solute loss;

[0050] The concentrated alkali tank and the storage tank are connected by the flow pump;

[0051] The heat exchanger is used to regulate the temperature of the alkali solution via cooling water.

[0052] The heat exchanger and the cooling tower are connected by the second proportional valve;

[0053] The cooling tower is used to provide cooling water;

[0054] The electrolyzer is used to decompose water under the action of an electric field to generate hydrogen and oxygen;

[0055] The electric pump is connected to the heat exchanger and the anode side of the electrolytic cell;

[0056] The inlet of the electrolytic cell is equipped with a second temperature sensor; the second temperature sensor is used to monitor the temperature of the alkaline solution entering the electrolytic cell.

[0057] In some embodiments, the system further includes a concentration controller and a temperature controller;

[0058] The concentration controller is connected to the level gauge, the pH sensor, the first proportional valve, and the flow pump;

[0059] The concentration controller is used to monitor and record concentration data, analyze water replenishment and alkali replenishment data, calculate and process data, and send execution commands.

[0060] The temperature controller is connected to the first temperature sensor, the second temperature sensor, the heating rod, and the second proportional valve;

[0061] The temperature controller is used to monitor and record temperature data, analyze heating and cooling data, calculate and process data, and send execution commands.

[0062] The embodiments of this application include at least the following beneficial effects: This application provides a method and system for the linkage control of alkali concentration and temperature. This scheme obtains the operating current of the electrolyzer; calculates the water consumption for water electrolysis based on the operating current of the electrolyzer, and obtains the alkali concentration change adjustment time; detects the pH value based on the alkali concentration change adjustment time to obtain the current pH value; compares the current pH value with a preset target pH value to obtain deionized water replenishment information and concentrated alkali replenishment information; adjusts the current pH value to within the preset target pH range based on the deionized water replenishment information and concentrated alkali replenishment information to obtain alkali concentration control information; monitors the alkali temperature based on the alkali concentration control information to obtain the current temperature value; compares the current temperature value with a preset target temperature value to obtain cooling water inflow information and heating duty cycle information; adjusts the current temperature value to within the preset target temperature range based on the cooling water inflow information and heating duty cycle information to obtain alkali temperature control information. This invention can automatically control and dynamically adjust the operating state of the electrolyzer, minimizing manual on-site operation and reducing safety risks. Attached Figure Description

[0063] Figure 1 This is a flowchart of the method for linkage control of alkali concentration and temperature provided in the embodiments of this application;

[0064] Figure 2 This is a schematic diagram of the concentration and temperature linkage control system provided in the embodiments of this application;

[0065] Figure 3 This is a flowchart of the alkali concentration control provided in the embodiments of this application;

[0066] Figure 4 This is a temperature control flowchart provided in an embodiment of this application;

[0067] Figure 5 This is a flowchart of the concentration and temperature linkage control provided in the embodiments of this application.

[0068] Reference numerals in the attached diagram: 1. Storage tank; 2. Heating rod; 3. Stirring device; 4. Level gauge; 5. pH sensor; 6. First temperature sensor; 7. Concentration controller; 8. Deionized water tank; 9. First proportional valve; 10. Concentrated alkali tank; 11. Flow pump; 12. Heat exchanger; 13. Second proportional valve; 14. Cooling tower; 15. Electric pump; 16. Second temperature sensor; 17. Temperature controller; 18. Electrolytic cell; 19. Separation and purification device; 20. Third temperature sensor. Detailed Implementation

[0069] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit it. In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with those of this application; they are merely examples of apparatuses and methods consistent with some aspects of the embodiments of this application as detailed in the appended claims.

[0070] It is understood that the terms “first,” “second,” etc., used in this application may be used herein to describe various concepts, but unless otherwise stated, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another. For example, without departing from the scope of the embodiments of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the words “if,” “when,” or “in response to a determination” as used herein may be interpreted as “when…” or “when…” or “in response to a determination.”

[0071] As used in this application, the terms "at least one", "multiple", "each", "any", etc., "at least one" includes one, two or more, "multiple" includes two or more, "each" refers to each of the corresponding multiples, and "any" refers to any one of the multiples.

[0072] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0073] Before providing a detailed description of the embodiments of this application, some of the nouns and terms involved in the embodiments of this application will be explained first. The nouns and terms involved in the embodiments of this application are subject to the following interpretations.

[0074] 1) 1.1M, 1.1 moles per liter (1.1 mol / L), represents the concentration unit of alkaline solution (such as KOH solution), that is, 1.1 moles of solute (KOH) are contained in each liter of solution;

[0075] 2) AEM, Anion Exchange Membrane, is a membrane that allows hydroxide ions (OH-) to pass through. - The selective thin film that allows gas to pass through but blocks it is the core component of the AEM electrolyzer;

[0076] 3) ALK, Alkaline Electrolyzer, is a traditional water electrolysis hydrogen production technology that uses a high-concentration alkaline solution (such as 20-30% KOH) as the electrolyte and separates gases through asbestos or porous membranes;

[0077] 4) KOH, potassium hydroxide, is a strong alkaline compound used as an electrolyte in the electrolysis of water to produce hydrogen.

[0078] The technical problem solved by this invention:

[0079] 1) A scheme for real-time control of alkaline solution concentration in AEM electrolyzer is proposed, which comprehensively considers the response methods for both concentration increase and decrease, and uses pH value as the control parameter, which can adjust the actual concentration more accurately than controlling the liquid level.

[0080] 2) A scheme for real-time control of the alkaline solution temperature in the electrolyzer is proposed to reduce the impact of temperature fluctuations on the operation of the electrolyzer;

[0081] 3) Develop a logic scheme for linkage control of alkali concentration and temperature, which can automatically control and dynamically adjust the operating status of the electrolyzer;

[0082] 4) Design an automated hydrogen production system to minimize manual on-site operations and reduce safety risks.

[0083] On one hand, embodiments of the present invention provide a method for the coordinated control of alkali concentration and temperature, referring to... Figure 1 The method includes the following steps:

[0084] Step S100: Obtain the operating current of the electrolytic cell;

[0085] Step S200: Calculate the water consumption for water electrolysis based on the working current of the electrolyzer, and obtain the adjustment time for changes in alkali concentration;

[0086] Step S300: Adjust the time according to the change in alkali concentration and detect the pH value to obtain the current pH value;

[0087] Step S400: Compare the current pH value with the preset target pH value to obtain information on deionized water replenishment and concentrated alkali replenishment.

[0088] Step S500: Adjust the current pH value to the preset target range based on the deionized water replenishment information and concentrated alkali replenishment information to obtain alkali concentration control information;

[0089] Step S600: Monitor the temperature of the alkali solution according to the alkali concentration control information to obtain the current temperature value;

[0090] Step S700: Compare the current temperature value with the preset target temperature value to obtain cooling water inlet flow rate information and heating duty cycle information;

[0091] Step S800: Adjust the current temperature value to the preset target range based on the cooling water inlet flow information and heating duty cycle information to obtain alkali solution temperature control information.

[0092] In some embodiments, step S200 of the present invention discloses calculating the water consumption mass of water electrolysis based on the operating current of the electrolyzer and obtaining the adjustment time for the change in alkali concentration includes:

[0093] Step S210: Calculate the water consumption mass for water electrolysis using the operating current of the electrolytic cell, obtaining the water consumption mass. The formulas used include:

[0094]

[0095] Where I is the operating current of the electrolytic cell, and t′ is the operating time. Let F be the molar mass of water, and F be the Faraday constant. For water consumption quality;

[0096] Step S220: The time point is set when the concentration of the alkali solution increases to 1.1M;

[0097] Step S230: Calculate the time required for the concentration to increase to 1.1M based on the time point and water consumption, thus obtaining the adjustment time for the alkali concentration change. The formulas used include:

[0098]

[0099] Where m is the initial mass of the alkali solution, and t is the adjustment time for the alkali solution concentration change when the concentration increases to 1.1M.

[0100] In some embodiments, step S400 of the present invention compares the current pH value with a preset target pH value to obtain deionized water replenishment information and concentrated alkali replenishment information, including:

[0101] Step S410: Compare the current pH value with the preset target pH value. If the target pH value is less than the current pH value, calculate the amount of deionized water to replenish and obtain the deionized water replenishment information.

[0102] Step S420: If the target pH value is greater than the current pH value, calculate the amount of concentrated alkali to be replenished and obtain the concentrated alkali replenishment information.

[0103] In some embodiments of the present invention, if the target pH value is greater than the current pH value in step S420, the concentrated alkali replenishment amount is calculated to obtain concentrated alkali replenishment amount information. The formula used includes:

[0104]

[0105] in, The initial target concentration of the alkali solution is 1M; Let t be the concentration of the alkali solution at time t; The concentration of the alkali solution to be replenished, V2 is the volume of the alkali solution in the storage tank at time t, V 浓碱 Information on the amount of concentrated alkali to be replenished.

[0106] In some embodiments, step S500 of the present invention discloses adjusting the current pH value to a preset target pH range based on the deionized water replenishment information and the concentrated alkali replenishment information to obtain alkali concentration control information, including:

[0107] Step S510: Based on the deionized water replenishment information and concentrated alkali replenishment information, adjust the current pH value to within ±5% of the target pH value and maintain it for more than 10 minutes to obtain alkali concentration control information.

[0108] In some embodiments, step S700 of the present invention compares the current temperature value with a preset target temperature value to obtain cooling water inflow information and heating duty cycle information, including:

[0109] Step S710: Compare the current temperature value with the preset target temperature value. When the current temperature value is higher than the target temperature value, calculate the cooling water inlet information and adjust the cooling water flow rate to cool down the temperature.

[0110] Step S720: When the current temperature value is lower than the target temperature value, calculate the heating duty cycle information and raise the temperature by controlling the duty cycle of the heating rod.

[0111] In some embodiments of the present invention, step S720, when the current temperature value is lower than the target temperature value, calculates the heating duty cycle information and raises the temperature by controlling the duty cycle of the heating rod. The formula used includes:

[0112] DC 加热 =K p e(t)+K i ∫ o t e(t)dt

[0113] Among them, K p It is the proportionality coefficient, K i It is the integral coefficient, e(t) is the temperature difference at time, DC 加热It is heating duty cycle information.

[0114] In some embodiments, step S800 of the present invention discloses adjusting the current temperature value to a preset target temperature range based on cooling water inflow information and heating duty cycle information to obtain alkali solution temperature control information, including:

[0115] Step S810: Based on the cooling water inlet flow rate information and heating duty cycle information, adjust the current temperature value within the range of ±0.5℃ of the target temperature value and maintain it for more than 5 minutes to obtain alkali solution temperature control information.

[0116] refer to Figure 2 This application also provides a system for linkage control of alkali concentration and temperature, used to realize the method of linkage control of alkali concentration and temperature as described above. The system includes a storage tank, a deionized water tank, a first proportional valve, a concentrated alkali tank, a flow pump, a heat exchanger, a second proportional valve, a cooling tower, an electric pump, and an electrolytic cell.

[0117] The storage tank is equipped with a heating rod, a stirring device, a level gauge, a pH sensor, and a first temperature sensor;

[0118] Heating rods are used to regulate the temperature of the alkali solution; stirring devices are used to stir the alkali solution in the tank; level gauges are used to monitor the volume of the alkali solution and assist in calculating the amount of water to be added; pH sensors are used to detect the pH value of the alkali solution; and the first temperature sensor is used to monitor the temperature of the alkali solution in the storage tank.

[0119] Deionized water tanks are used to store deionized water and dilute alkaline solutions;

[0120] The deionized water tank and the storage tank are connected by a first proportional valve;

[0121] Concentrated alkali tanks are used to store alkali solutions and replenish solute losses.

[0122] The concentrated alkali tank and the storage tank are connected by a flow pump;

[0123] The heat exchanger is used to regulate the temperature of the alkali solution via cooling water;

[0124] The heat exchanger and the cooling tower are connected via a second proportional valve;

[0125] Cooling towers are used to provide cooling water;

[0126] Electrolyzers are used to decompose water under the influence of an electric field, producing hydrogen and oxygen.

[0127] The electric pump connects the heat exchanger and the anode side of the electrolytic cell;

[0128] The inlet of the electrolytic cell is equipped with a second temperature sensor; the second temperature sensor is used to monitor the temperature of the alkaline solution entering the electrolytic cell.

[0129] In some embodiments, the system for linkage control of alkali concentration and temperature disclosed in this invention further includes a concentration controller and a temperature controller;

[0130] The concentration controller is connected to a level gauge, a pH sensor, a first proportional valve, and a flow pump;

[0131] The concentration controller is used to monitor and record concentration data, analyze water replenishment and alkali replenishment data, calculate and process data, and send execution commands.

[0132] The temperature controller is connected to the first temperature sensor, the second temperature sensor, the heating rod, and the second proportional valve; the temperature controller is used to monitor and record temperature data, analyze heating and cooling data, calculate and process data, and send execution commands.

[0133] As an optional implementation, the system for linkage control of alkali concentration and temperature in this embodiment of the invention mainly includes the following components: a storage tank 1 for storing KOH solution, the initial KOH solution concentration of which can be set to 1M; a heating rod 2 is provided at the bottom of the storage tank 1 for heating the alkali solution in the tank, and a stirring device 3 is also provided for stirring the alkali solution in the tank evenly; a level gauge 4, a pH sensor 5, and a first temperature sensor 6 are also provided to monitor the level, pH value, and temperature of the alkali solution in the tank, respectively. To meet the adjustment of the alkali concentration in the storage tank 1, the storage tank 1 is connected to a deionized water tank 8 and a concentrated alkali tank 10, respectively. The deionized water tank 8 and the storage tank 1 are connected through a first proportional valve 9, and the concentrated alkali tank 10 is connected to the storage tank 1 through a flow pump 11. The alkali solution enters the anode side of the electrolytic cell 18 from the storage tank 1 via a heat exchanger 12 and then through an electric pump 15. A second temperature sensor 16 is provided at the inlet of the electrolytic cell 18 to monitor the temperature of the alkali solution entering the electrolytic cell 18. Unreacted alkali and oxygen on the anode side enter the storage tank 1, while hydrogen on the cathode side is purified by the separation and purification device 19 and then collected and stored. The separated alkali is returned to the storage tank 1. A reflux is formed between the heat exchanger 12 and the cooling tower 14. The cooling water temperature of the cooling tower 14 is detected by the third temperature sensor 20, enters the heat exchanger 12 through the second proportional valve 13, completes the heat exchange, and then flows back to the cooling tower 14.

[0134] The components are executed by commands sent by the controller, which includes two controllers: a concentration controller 7 and a temperature controller 17. The level gauge 4, pH sensor 5, first proportional valve 9, and flow pump 11 communicate with the concentration controller 7, while the first temperature sensor 6, second temperature sensor 16, heating rod 2, and second proportional valve 13 communicate with the temperature controller 17. The functions of the concentration controller 7 and temperature controller 17 include, but are not limited to: data recording, analysis and judgment, calculation and processing, and sending execution commands.

[0135] As an optional implementation method, refer to Figure 2 and Figure 3In the method for linkage control of alkali concentration and temperature in this embodiment of the invention, the method for the alkali concentration control stage is as follows:

[0136] (1) Monitor the operating current of AEM electrolysis cell 18 and feed it back to concentration controller 7 to calculate water consumption. The formula for calculating water consumption is as follows:

[0137]

[0138] In the formula, I is the operating current of electrolytic cell 18 (A), and t′ is the operating time. Let F be the molar mass of water, and F be the Faraday constant. Water consumption quality.

[0139] (2) Due to the water electrolysis reaction, the concentration of the alkali solution will gradually increase in the short term. Therefore, we directly take the time t required for the concentration to increase to 1.1M as the time node, and calculate the time t required for the concentration to increase to 1.1M. The calculation formula is as follows:

[0140]

[0141] In the formula, m is the initial mass of the alkali solution, and t is the adjustment time for the alkali solution concentration change when the concentration increases to 1.1M.

[0142] (3) After calculating the concentration adjustment time t based on the real-time operating current, the pH sensor 5 feeds back the current pH value (pH2) to the concentration controller 7 every time t, and compares it with the target pH value (pH1). pH1 corresponds to a 1M alkali solution concentration. The pH value can be converted according to the concentration. The conversion formula is:

[0143]

[0144] In the formula, It refers to the concentration of the alkaline solution.

[0145] (4) Determine the relative values ​​of pH2 and pH1. If pH1 > pH2, it indicates a decrease in KOH solute, which may be due to solute precipitation or electrode corrosion, requiring the addition of concentrated alkali. If pH1 < pH2, it indicates water consumption, requiring the addition of deionized water. If the two are equal, no action is needed. Simultaneously, the level gauge 4 records the liquid level in the storage tank 1 at this time.

[0146] (5) The method for replenishing deionized water is as follows: a feedforward-feedback control method is adopted. The pH sensor 5 and the liquid level gauge 4 record and feed back the pH and liquid level, respectively. The concentration controller 7 calculates the required amount of deionized water to be replenished. The formula for calculating the amount of water to be replenished is as follows:

[0147]

[0148] In the formula, The information provided is for replenishing deionized water. PH1 is the target pH value, PH2 is the current pH value, and V2 is the volume of alkaline solution in storage tank 1 at time t, which can be calculated based on the liquid level.

[0149] The concentration controller 7 controls the opening degree and opening time of the first proportional valve 9 according to the water replenishment volume. When the specified water inflow volume is reached, the first proportional valve 9 closes, and the water replenishment is completed. After the stirring device 3 stirs for a period of time and the solution in the storage tank 1 is evenly mixed, the pH 2 and pH 1 are collected and judged again, and then PI closed-loop control is used until the pH 2 approaches the pH 1.

[0150] (6) The concentrated alkali replenishment method is as follows: The concentration controller 7 calculates the amount of concentrated alkali to be replenished based on the difference between pH1 and pH2. The calculation formula is as follows:

[0151]

[0152] In the formula, The initial target concentration of the alkali solution is 1M; Let t be the concentration of the alkali solution at time t; The concentration of the alkali solution to be replenished, V2 is the volume of the alkali solution in storage tank 1 at time t, V 浓碱 Information on the amount of concentrated alkali to be replenished.

[0153] Concentrated alkali flows from concentrated alkali tank 10 into storage tank 1 via flow pump 11. Concentration controller 7 controls the pump's operation based on the flow rate feedback from flow pump 11, ensuring that the amount of concentrated alkali entering storage tank 1 equals the calculated value. PI closed-loop control is also used, continuously correcting the flow until pH2 stabilizes within the range of pH1 ± 5%.

[0154] As an optional implementation method, refer to Figure 2 and Figure 4 In the method for linkage control of alkali concentration and temperature in this embodiment of the invention, the method for the alkali temperature control stage is as follows:

[0155] (1) Set the target temperature (target temperature value) T1 of the electrolytic cell 18 to the temperature controller 17, monitor the inlet temperature (current temperature value) T2 of the electrolytic cell 18 through the second temperature sensor 16, and monitor the cooling water temperature T3 in the cooling tower 14 through the third temperature sensor 20.

[0156] (2) Determine the difference between the target temperature T1 and the inlet temperature T2 of the electrolytic cell 18, and the temperature controller 17 will send different operation commands.

[0157] (3) If the target temperature T1 < the inlet temperature T2, the heating rod 2 in the storage tank 1 stops heating. Simultaneously, based on the temperature difference between T2 and T1, the amount of heat to be exchanged in the heat exchanger 12 is calculated. Then, based on the temperature difference between the cooling water temperature T3 and T2, the amount of cooling water entering the heat exchanger 12 from the cooling water tower 14 is calculated. Finally, the opening degree and opening time of the second proportional valve 13 are controlled by the temperature controller 17 to control the cooling water inflow. The cooling water flow calculation formula is as follows:

[0158]

[0159] In the formula, C 碱液 It is the specific heat capacity of the alkaline solution, m 碱液 It is the mass flow rate of the alkali solution, C 冷却水 It is the specific heat capacity of cooling water, m 冷却水 It refers to the cooling water volume.

[0160] (4) If the target temperature T1 > the inlet temperature T2, keep the opening state of the second proportional valve 13 unchanged to ensure that the heat exchanger 12 has a constant heat exchange capacity; then, based on the temperature difference between T1 and T2, calculate the heating duty cycle of the heating rod 2, and thus control the working time of the heating rod 2 to increase the inlet temperature T2. The duty cycle is the ratio of the excitation time to the total cycle time in intermittent, continuous, or short-time operation, and is used to measure the on or off state of the switch. The formula for calculating the heating duty cycle is as follows:

[0161] DC 加热 =K p e(t)+K i ∫0 t e(t)dt

[0162] Among them, K p It is the first proportionality coefficient (proportional coefficient), K i It is the first integral coefficient (integral coefficient), e(t) is the temperature difference at time t, DC 加热 It is heating duty cycle information.

[0163] (5) The above steps are repeatedly executed using the PI closed-loop control method until T1 is maintained within the range of T0±0.5℃, all temperature control actuators maintain their current state of operation, and the temperature control work is completed.

[0164] As an optional implementation method, refer to Figure 5 The method for controlling the concentration and temperature of the alkali solution in this invention is as follows:

[0165] (1) First, control the concentration of the alkali solution. When the pH value of the alkali solution is maintained within ±5% of the target pH value and the maintenance time exceeds 10 minutes, the concentration can be considered to be stable.

[0166] (2) The pH sensor 5 communicates with the temperature controller 17. After the concentration stabilizes, the temperature controller 17 receives the instruction to control the heating rod 2, the second proportional valve 13 and other temperature regulating devices to work. For specific adjustment methods, please refer to the alkaline solution temperature control method in the previous section (method of alkaline solution temperature control stage).

[0167] (3) When the inlet temperature T2 is kept within the target temperature T1 ± 0.5℃ and maintained for more than 5 minutes, the temperature control is considered to be completed. At this point, all concentration and temperature control components will continue to operate in their current state.

[0168] The beneficial effects of the embodiments of the present invention are as follows:

[0169] (1) It takes into account the two situations of rising and falling alkali concentration in electrolytic cell 18, and can adjust the alkali concentration in AEM electrolytic cell 18 in real time. With pH value as the control parameter, it can adjust the actual concentration more accurately than controlling the liquid level.

[0170] (2) Real-time control of the alkaline solution temperature of electrolytic cell 18 to reduce the impact of temperature fluctuations on the operation of electrolytic cell 18;

[0171] (3) The alkaline solution concentration and temperature are controlled in a coordinated manner, and the operating status of the electrolytic cell 18 can be dynamically adjusted in a fully automatic manner.

[0172] (4) Automated hydrogen production systems can minimize manual on-site operations and reduce safety risks.

[0173] This application also provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the above-described method. This electronic device can be any smart terminal, including tablet computers, in-vehicle computers, etc.

[0174] It is understood that the content of the above method embodiments is applicable to this device embodiment. The specific functions implemented by this device embodiment are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0175] Electronic devices include:

[0176] The processor can be implemented using a general-purpose CPU (Central Processing Unit), microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to achieve the technical solutions provided in the embodiments of this application.

[0177] The memory can be implemented in the form of read-only memory (ROM), static storage device, dynamic storage device, or random access memory (RAM). The memory can store the operating system and other applications. When the technical solutions provided in the embodiments of this specification are implemented through software or firmware, the relevant program code is stored in the memory and called by the processor to execute the methods described in the embodiments of this application.

[0178] Input / output interfaces are used to implement information input and output;

[0179] The communication interface is used to enable communication and interaction between this device and other devices. Communication can be achieved through wired means (such as USB, Ethernet cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.).

[0180] A bus is used to transfer information between various components of a device, such as processors, memory, input / output interfaces, and communication interfaces.

[0181] The processor, memory, input / output interfaces, and communication interfaces communicate with each other within the device via a bus.

[0182] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method.

[0183] It is understood that the content of the above method embodiments is applicable to this storage medium embodiment. The specific functions implemented in this storage medium embodiment are the same as those in the above method embodiments, and the beneficial effects achieved are also the same as those achieved in the above method embodiments.

[0184] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described method.

[0185] It is understood that the content of the above method embodiments is applicable to the embodiments of this program product. The specific functions implemented by the embodiments of this program product are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0186] Memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. Furthermore, memory may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, memory may optionally include memory remotely located relative to the processor, and these remote memories can be connected to the processor via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0187] The method, apparatus, electronic device, storage medium, and program product for linkage control of alkali concentration and temperature provided in this application embodiment can adjust the alkali concentration of the AEM electrolytic cell in real time, and use pH value as the control parameter, which can adjust the actual concentration more accurately than controlling the liquid level.

[0188] The embodiments described in this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided by the embodiments of this application. As those skilled in the art will know, with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of this application are also applicable to similar technical problems.

[0189] Those skilled in the art will understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of this application, and may include more or fewer steps than shown, or combine certain steps, or different steps.

[0190] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0191] Those skilled in the art will understand that all or some of the steps in the methods disclosed above, as well as the functional modules / units in the systems and devices, can be implemented as software, firmware, hardware, or suitable combinations thereof.

[0192] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0193] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0194] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of the units described above is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0195] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0196] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0197] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes multiple instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing programs, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0198] The preferred embodiments of the present application have been described above with reference to the accompanying drawings, but this does not limit the scope of the claims of the present application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and substance of the embodiments of the present application shall be within the scope of the claims of the present application.

Claims

1. A method for linkage control of alkali concentration and temperature, characterized in that, The method includes the following steps: Obtain the operating current of the electrolytic cell; The water consumption for water electrolysis is calculated based on the working current of the electrolyzer, and the adjustment time for changes in alkali concentration is obtained. The pH value is detected based on the change in alkali concentration over time to obtain the current pH value; The current pH value is compared with the preset target pH value to obtain information on the amount of deionized water replenished and the amount of concentrated alkali replenished. Based on the deionized water replenishment information and the concentrated alkali replenishment information, the current pH value is adjusted to the preset pH target range to obtain alkali concentration control information; The temperature of the alkali solution is monitored based on the alkali concentration control information to obtain the current temperature value; The current temperature value is compared with the preset target temperature value to obtain cooling water inflow information and heating duty cycle information; Based on the cooling water inflow information and the heating duty cycle information, the current temperature value is adjusted to the preset temperature target range to obtain alkali solution temperature control information.

2. The method according to claim 1, characterized in that, The step of calculating the water consumption mass for water electrolysis based on the operating current of the electrolyzer and obtaining the adjustment time for changes in alkali concentration includes: The water consumption mass of water electrolysis is calculated using the operating current of the electrolyzer, and the formulas used include: Where I is the operating current of the electrolytic cell, t ′ For working hours, Let F be the molar mass of water, and F be the Faraday constant. The water consumption mass; The time point was set when the concentration of the alkali solution increased to 1.1M; Based on the aforementioned time points and water consumption, the time required for the concentration to increase to 1.1M is calculated, yielding the adjustment time for the alkali concentration change. The formulas used include: Where m is the initial mass of the alkali solution, and t is the adjustment time for the alkali solution concentration change when the concentration increases to 1.1M.

3. The method according to claim 1, characterized in that, The step of comparing the current pH value with a preset target pH value to obtain deionized water replenishment information and concentrated alkali replenishment information includes: The current pH value is compared with the preset target pH value. If the target pH value is less than the current pH value, the amount of deionized water to be replenished is calculated to obtain the deionized water replenishment information. If the target pH value is greater than the current pH value, the amount of concentrated alkali to be replenished is calculated to obtain the concentrated alkali replenishment information.

4. The method according to claim 3, characterized in that, If the target pH value is greater than the current pH value, the concentrated alkali replenishment amount is calculated to obtain concentrated alkali replenishment amount information. The formula used includes: in, The initial target alkali concentration is 1M; Let t be the concentration of the alkali solution at time t; The concentration of the alkali solution to be replenished, V2 is the volume of the alkali solution in the storage tank at time t, V 浓碱 Information on the amount of concentrated alkali to be replenished.

5. The method according to claim 1, characterized in that, The step of adjusting the current pH value to a preset target range based on the deionized water replenishment information and the concentrated alkali replenishment information to obtain alkali concentration control information includes: Based on the information on the amount of deionized water replenished and the information on the amount of concentrated alkali replenished, the current pH value is adjusted within the range of ±5% of the target pH value and maintained for more than 10 minutes to obtain alkali concentration control information.

6. The method according to claim 1, characterized in that, The step of comparing the current temperature value with a preset target temperature value to obtain cooling water inflow information and heating duty cycle information includes: The current temperature value is compared with the preset target temperature value. When the current temperature value is higher than the target temperature value, the cooling water inlet information is calculated, and the cooling water flow rate is adjusted to cool down the temperature. When the current temperature value is lower than the target temperature value, the heating duty cycle information is calculated, and the temperature is increased by controlling the duty cycle of the heating rod.

7. The method according to claim 6, characterized in that, When the current temperature value is lower than the target temperature value, the heating duty cycle information is calculated, and the temperature is increased by controlling the duty cycle of the heating rod. The formula used includes: DC 加热 =K p e(t)+K i ∫0 t e(t)dt Among them, K p It is the proportionality coefficient, K i It is the integral coefficient, e(t) is the temperature difference at time, DC 加热 It is heating duty cycle information.

8. The method according to claim 1, characterized in that, The step of adjusting the current temperature value to a preset target temperature range based on the cooling water inflow information and the heating duty cycle information to obtain alkali solution temperature control information includes: Based on the cooling water inflow information and the heating duty cycle information, the current temperature value is adjusted within the range of ±0.5℃ of the target temperature value and maintained for more than 5 minutes to obtain alkali solution temperature control information.

9. A system for linked control of alkali concentration and temperature, used to implement the method for linked control of alkali concentration and temperature as described in any one of claims 1-8, characterized in that, The system includes a storage tank, a deionized water tank, a first proportional valve, a concentrated alkali tank, a flow pump, a heat exchanger, a second proportional valve, a cooling tower, an electric pump, and an electrolytic cell. The storage tank is equipped with a heating rod, a stirring device, a level gauge, a pH sensor, and a first temperature sensor; The heating rod is used to regulate the temperature of the alkali solution; the stirring device is used to stir the alkali solution in the tank; the level gauge is used to monitor the volume of the alkali solution and assist in calculating the amount of water to be added; the pH sensor is used to detect the pH value of the alkali solution; the first temperature sensor is used to monitor the temperature of the alkali solution in the storage tank. The deionized water tank is used to store deionized water and dilute alkaline solution. The deionized water tank and the storage tank are connected by the first proportional valve; The concentrated alkali tank is used to store alkali solution and replenish solute loss; The concentrated alkali tank and the storage tank are connected by the flow pump; The heat exchanger is used to regulate the temperature of the alkali solution via cooling water. The heat exchanger and the cooling tower are connected by the second proportional valve; The cooling tower is used to provide cooling water; The electrolyzer is used to decompose water under the action of an electric field to generate hydrogen and oxygen; The electric pump is connected to the heat exchanger and the anode side of the electrolytic cell; The inlet of the electrolytic cell is equipped with a second temperature sensor; the second temperature sensor is used to monitor the temperature of the alkaline solution entering the electrolytic cell.

10. The system according to claim 9, characterized in that, The system also includes a concentration controller and a temperature controller; The concentration controller is connected to the level gauge, the pH sensor, the first proportional valve, and the flow pump; The concentration controller is used to monitor and record concentration data, analyze water replenishment and alkali replenishment data, calculate and process data, and send execution commands. The temperature controller is connected to the first temperature sensor, the second temperature sensor, the heating rod, and the second proportional valve; The temperature controller is used to monitor and record temperature data, analyze heating and cooling data, calculate and process data, and send execution commands.

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