A sacrificial anode protection system and method for suppressing reverse current in an alkaline water electrolytic cell

Abstract

The present invention relates to the technical field of electrolytic hydrogen production, and discloses a sacrificial anode protection system and method for suppressing reverse current of an alkaline water electrolyzer. The sacrificial anode protection system for suppressing reverse current of an alkaline water electrolyzer comprises: a plurality of sacrificial anode modules; wherein the sacrificial anode module comprises an alkali box and a salt bridge; the alkali box contains alkali solution and is connected to the cathode terminal of the alkaline water electrolyzer through a wire; the salt bridge connects the alkaline water electrolyzer and the alkali box respectively, and is used to suppress reverse current of the alkaline water electrolyzer. The present invention arranges a plurality of sacrificial anode modules outside the alkaline water electrolyzer, and then utilizes the plurality of sacrificial anode modules to suppress oxidation of the cathode by reverse current, does not pollute the alkali solution in the alkaline water electrolyzer, improves the stability of the alkaline water electrolyzer under repeated start-up and shutdown operation conditions, and prolongs the service life of the electrodes of the alkaline water electrolyzer.

Description

Technical Field

[0001] The invention relates to the technical field of electrolytic hydrogen production, and in particular to a sacrificial anode protection system and method for suppressing reverse current in an alkaline water electrolytic cell. Background Art

[0002] Since renewable energy is usually accompanied by intermittent fluctuations, hydrogen is easier to store or transport, and green hydrogen can achieve zero carbon emissions during the preparation process, so hydrogen is considered an attractive energy storage system and the purest green energy. Among them, water electrolysis is one of the most important means of green hydrogen preparation. Alkaline water electrolysis is one of the most widely used water electrolysis technologies in industrial-grade large-scale hydrogen production technologies. It is the most mature and has low investment and operating costs, but there are problems such as alkali loss, corrosion, and high energy consumption. The performance of the alkaline water hydrogen production electrolyzer directly affects the hydrogen production efficiency of the entire hydrogen production system, so it is the core of the entire hydrogen production equipment.

[0003] Most alkaline water hydrogen production electrolyzers are bipolar type, which are assembled by repeatedly stacking electrolytic chambers. They include dozens or even hundreds of electrolytic chambers. Two adjacent plates form a cathode chamber and an anode chamber. The flow path of the alkali solution usually adopts a series mode, that is, the alkali solution passes through each cathode chamber or anode chamber of the electrolyzer in sequence. Although the electrolytic chamber is scalable, the electrolyzer may have serious stability problems under repeated startup and shutdown operating conditions under the fluctuation of renewable energy power. Summary of the invention

[0004] In view of this, the present invention provides a sacrificial anode protection system and method for suppressing reverse current of an alkaline water electrolysis cell, so as to solve the problem of poor stability of the alkaline water electrolysis cell under repeated startup and shutdown operation conditions.

[0005] In a first aspect, the present invention provides a sacrificial anode protection system for suppressing reverse current in an alkaline water electrolysis cell, characterized in that the system comprises: a plurality of sacrificial anode modules; wherein the sacrificial anode modules comprise an alkali tank and a salt bridge;

[0006] The alkali box contains alkali solution and is connected to the cathode terminal of the alkali water electrolyzer through a wire;

[0007] The salt bridge connects the alkaline water electrolyzer and the alkaline tank respectively, and is used to suppress the reverse current of the alkaline water electrolyzer.

[0008] The present embodiment provides a sacrificial anode protection system for suppressing reverse current in an alkaline water electrolysis cell. A plurality of sacrificial anode modules are arranged outside the alkaline water electrolysis cell, and then the plurality of sacrificial anode modules are used to suppress oxidation of the cathode by the reverse current, thereby delaying the performance deterioration of the alkaline water electrolysis cell, and will not cause pollution to the alkaline solution in the alkaline water electrolysis cell. The stability of the alkaline water electrolysis cell under repeated startup and shutdown operation conditions is improved, and the service life of the electrodes in the alkaline water electrolysis cell is extended.

[0009] In a second aspect, the present invention provides a method for suppressing reverse current in an alkaline water electrolysis cell, characterized in that the sacrificial anode protection system for suppressing reverse current in an alkaline water electrolysis cell is applied, and the method comprises:

[0010] Acquire shutdown state data of the alkaline water electrolyzer, and determine the current density distribution and potential distribution of the cathode reverse current in the shutdown state of the alkaline water electrolyzer by using the finite element method based on the shutdown state data of the alkaline water electrolyzer;

[0011] Select various types of metals as sacrificial anodes based on the Bourbaix diagram;

[0012] Obtain sacrificial anode protection current data, and determine the cathodic protection potential distribution and cathodic protection current distribution of the alkaline water electrolyzer using the finite element method based on the sacrificial anode protection current data;

[0013] Determine the number of sacrificial anode modules based on the current density distribution and potential distribution of the cathode reverse current and the cathodic protection potential distribution and cathodic protection current distribution of the alkaline water electrolyzer;

[0014] A sacrificial anode protection system is constructed at the alkaline water electrolyzer based on the number of sacrificial anode modules to suppress reverse current in the alkaline water electrolyzer.

[0015] The present embodiment provides a method for suppressing reverse current in an alkaline water electrolyzer. The current density distribution and potential distribution of the cathode reverse current in the shutdown state of the alkaline water electrolyzer are simulated, and a sacrificial anode is selected to simulate the cathodic protection potential distribution and cathodic protection current distribution of the sacrificial anode in the alkaline water electrolyzer, so as to ensure that the selected sacrificial anode distribution satisfies the uniformity of potential and current density, and completely offsets the damage of the reverse current to the cathode of the alkaline electrolyzer, prevents over-protection and under-protection, improves the stability of the alkaline water electrolyzer under repeated startup and shutdown operation conditions, and prolongs the service life of the electrodes in the alkaline water electrolyzer.

[0016] In an optional embodiment, based on the shutdown state data of the alkaline water electrolyzer, the current density distribution and potential distribution of the cathode reverse current in the shutdown state of the alkaline water electrolyzer are determined by using the finite element method, including:

[0017] Determining the resistivity, scalar potential and potential flux of reverse current in the alkaline water electrolyzer based on the shutdown state data of the alkaline water electrolyzer;

[0018] The conductivity differential equation of alkaline water electrolyzer is constructed based on the resistivity, scalar potential and potential flux of reverse current;

[0019] Obtaining the boundary conditions of the potential surface at the inlet and outlet of the alkali solution and the polarization curve of the bipolar plate, and determining the node potential of the alkaline water electrolyzer based on the conductive differential equation, the boundary conditions of the potential surface at the inlet and outlet of the alkali solution and the polarization curve of the bipolar plate;

[0020] The current density distribution and potential distribution of the cathode reverse current in the shutdown state of the alkaline water electrolyzer are determined based on the node potential of the alkaline water electrolyzer.

[0021] The present embodiment provides a method for suppressing the reverse current of an alkaline water electrolyzer. The node potential of the alkaline water electrolyzer is determined based on the conductive differential equation, the boundary conditions of the alkali solution inlet and outlet potential surfaces, and the bipolar plate polarization curve. The potential of each unit node of the alkaline water electrolyzer is simulated, thereby achieving accurate simulation of the current density distribution and potential distribution of the cathode reverse current when the alkaline water electrolyzer is in the shutdown state.

[0022] In an optional embodiment, the node potential of the alkaline water electrolyzer is determined based on the conductive differential equation, the boundary conditions of the alkali solution inlet and outlet potential surfaces, and the bipolar plate polarization curve, including:

[0023] Dividing the area formed by the electrolytic cell anode, bipolar plates and electrolytic cell cathode in the alkaline water electrolyzer into a plurality of unit areas and a plurality of nodes; wherein the number of nodes is the same as the number of electrolytic cells in the electric field of the alkaline water electrolyzer;

[0024] The scalar potential of the reverse current is interpolated based on the undetermined potentials of multiple nodes to generate a three-dimensional electric field definition domain;

[0025] Construct weight functions based on undetermined potentials at multiple nodes and the three-dimensional electric field domain;

[0026] Based on the three-dimensional electric field domain and weight function, the conductivity differential equation is transformed into a boundary integral equation using the weighted residual method.

[0027] Based on the boundary integral equation, the boundary conditions of the inlet and outlet potential surfaces of the alkali solution and the polarization curve of the bipolar plate, the matrix equation is constructed using the finite element method.

[0028] The shutdown potential distribution model of alkaline water electrolyzer was constructed based on matrix equations and boundary conditions of the potential surface of the inlet and outlet of alkali solution.

[0029] The shutdown potential distribution model of the alkaline water electrolyzer is iteratively solved to generate the node potential of the alkaline water electrolyzer.

[0030] The present embodiment provides a method for suppressing reverse current of an alkaline water electrolyzer. The method generates the node potential of the alkaline water electrolyzer by constructing a shutdown potential distribution model of the alkaline water electrolyzer and iteratively solving the shutdown potential distribution model of the alkaline water electrolyzer, thereby improving the simulation accuracy of the node potential of the alkaline water electrolyzer.

[0031] In an optional embodiment, determining the current density distribution and potential distribution of the cathode reverse current in the alkaline water electrolyzer in a shutdown state based on the node potential of the alkaline water electrolyzer includes:

[0032] Determine the potential distribution of reverse current based on the node potential of the alkaline water electrolyzer;

[0033] Determine the relationship between current density and potential based on the bipolar plate polarization curve;

[0034] Based on the potential distribution of the reverse current, the current density distribution of the reverse current is determined using the relationship between the current density and the potential.

[0035] The present embodiment provides a method for suppressing reverse current in an alkaline water electrolyzer, which realizes accurate simulation of the current density distribution and potential distribution of the cathode reverse current in the shutdown state of the alkaline water electrolyzer through the bipolar plate polarization curve.

[0036] In an optional embodiment, based on sacrificial anode protection current data, the cathodic protection potential distribution and cathodic protection current distribution of the alkaline water electrolyzer are determined using the finite element method, including:

[0037] Determining the scalar potential and potential flux of the sacrificial anode based on the sacrificial anode protection current data;

[0038] Obtain the resistivity, scalar potential and potential flux of the sacrificial anode protection current, and construct the sacrificial anode conductivity differential equation based on the resistivity, scalar potential and potential flux of the sacrificial anode protection current;

[0039] Obtaining the polarization relationship between current density and potential and electrode boundary conditions, and determining the sacrificial anode node potential based on the sacrificial anode conductivity differential equation, the polarization relationship between current density and potential and electrode boundary conditions;

[0040] The cathodic protection potential distribution and cathodic protection current distribution of alkaline water electrolyzer are determined based on the sacrificial anode node potential.

[0041] The present embodiment provides a method for suppressing reverse current in an alkaline water electrolysis cell. The sacrificial anode node potential is determined based on the sacrificial anode conductivity differential equation, the polarization relationship between current density and potential, and the electrode boundary conditions. The cathodic protection potential distribution and cathodic protection current distribution of the alkaline water electrolysis cell are then determined based on the sacrificial anode node potential. This achieves accurate simulation of the cathodic protection potential distribution and cathodic protection current distribution corresponding to different types of sacrificial anodes, and ensures that the distribution of the selected sacrificial anodes satisfies the uniformity of potential and current density.

[0042] In an optional embodiment, the number of sacrificial anode modules is determined based on the current density distribution and potential distribution of the cathode reverse current and the cathodic protection potential distribution and cathodic protection current distribution of the alkaline water electrolyzer, including:

[0043] Obtaining the cathode radius and the number of electrolytic chambers, and determining the total sacrificial anode protection area based on the cathode radius and the number of electrolytic chambers;

[0044] Determine the total protection current based on the total protection area of ​​the sacrificial anode and the current density distribution of the reverse current;

[0045] The sacrificial anode output current is determined based on the cathodic protection current distribution, and the number of sacrificial anode modules is determined based on the sacrificial anode output current and the total protection current.

[0046] This embodiment provides a method for suppressing reverse current in an alkaline water electrolysis cell. The number of sacrificial anode modules is determined based on the sacrificial anode output current and the total protection current, thereby ensuring that the sacrificial anode output current can completely offset the damage to the cathode of the alkaline electrolysis cell caused by the reverse current, thereby preventing over-protection and under-protection.

[0047] In a third aspect, the present invention provides a device for suppressing reverse current in an alkaline water electrolysis cell, comprising:

[0048] The first determination module is used to obtain the shutdown state data of the alkaline water electrolyzer, and determine the current density distribution and potential distribution of the cathode reverse current in the shutdown state of the alkaline water electrolyzer by using the finite element method based on the shutdown state data of the alkaline water electrolyzer;

[0049] A selection module, used to select various types of metals as sacrificial anodes based on the Bourbaix diagram;

[0050] The second determination module is used to obtain sacrificial anode protection current data, and based on the sacrificial anode protection current data, determine the cathodic protection potential distribution and cathodic protection current distribution of the alkaline water electrolyzer by using the finite element method;

[0051] A third determination module is used to determine the number of sacrificial anode modules based on the current density distribution and potential distribution of the cathode reverse current and the cathode protection potential distribution and cathode protection current distribution of the alkaline water electrolyzer;

[0052] A building module is provided for building a sacrificial anode protection system at an alkaline water electrolyzer based on the number of sacrificial anode modules to suppress reverse current of the alkaline water electrolyzer.

[0053] In an optional implementation, the first determining module includes:

[0054] A first determination submodule is used to determine the resistivity, scalar potential and potential flux of the reverse current in the alkaline water electrolyzer based on the shutdown state data of the alkaline water electrolyzer;

[0055] A first construction submodule is used to construct an alkaline water electrolyzer conductivity differential equation based on the resistivity, scalar potential and potential flux of the reverse current;

[0056] The second determination submodule is used to obtain the boundary conditions of the potential surface of the inlet and outlet of the alkali solution and the polarization curve of the bipolar plate, and determine the node potential of the alkaline water electrolyzer based on the conductive differential equation, the boundary conditions of the potential surface of the inlet and outlet of the alkali solution and the polarization curve of the bipolar plate;

[0057] The third determination submodule is used to determine the current density distribution and potential distribution of the cathode reverse current in the shutdown state of the alkaline water electrolyzer based on the node potential of the alkaline water electrolyzer.

[0058] In an optional implementation, the second determining submodule includes:

[0059] A division unit is used to divide the area formed by the electrolytic cell anode, bipolar plate and electrolytic cell cathode in the alkaline water electrolyzer into a plurality of unit areas and a plurality of nodes; wherein the number of nodes is the same as the number of electrolytic cells in the electric field of the alkaline water electrolyzer;

[0060] A difference unit is used to interpolate the scalar potential of the reverse current based on the potentials to be determined at multiple nodes to generate a three-dimensional electric field definition domain;

[0061] A first construction unit is used to construct a weight function based on the undetermined potentials of multiple nodes and a three-dimensional electric field definition domain;

[0062] A conversion unit, used for converting the conductive differential equation into a boundary integral equation by using a weighted residual method based on a three-dimensional electric field definition domain and a weight function;

[0063] The second construction unit is used to construct a matrix equation using a finite element method based on a boundary integral equation, boundary conditions of the alkali solution inlet and outlet potential surfaces, and a bipolar plate polarization curve;

[0064] The third construction unit is used to construct a shutdown potential distribution model of the alkaline water electrolyzer based on the matrix equation and the boundary conditions of the potential surface of the alkali solution inlet and outlet;

[0065] The iterative solution unit is used for iteratively solving the shutdown potential distribution model of the alkaline water electrolysis cell to generate the node potential of the alkaline water electrolysis cell.

[0066] In an optional implementation, the third determining submodule includes:

[0067] A first determining unit, configured to determine a potential distribution of a reverse current based on a node potential of an alkaline water electrolyzer;

[0068] a second determination unit, configured to determine a relationship between current density and potential based on a bipolar plate polarization curve;

[0069] The third determining unit is configured to determine the current density distribution of the reverse current based on the potential distribution of the reverse current by utilizing the relationship between the current density and the potential.

[0070] In an optional implementation, the second determining module includes:

[0071] A fourth determination submodule, used to determine the scalar potential and potential flux of the sacrificial anode based on the sacrificial anode protection current data;

[0072] The second construction submodule is used to obtain the resistivity, scalar potential and potential flux of the sacrificial anode protection current, and construct the sacrificial anode conductive differential equation based on the resistivity, scalar potential and potential flux of the sacrificial anode protection current;

[0073] A fifth determination submodule is used to obtain the polarization relationship between current density and potential and the electrode boundary conditions, and determine the sacrificial anode node potential based on the sacrificial anode conductivity differential equation, the polarization relationship between current density and potential and the electrode boundary conditions;

[0074] The sixth determination submodule is used to determine the cathodic protection potential distribution and the cathodic protection current distribution of the alkaline water electrolyzer based on the sacrificial anode node potential.

[0075] In an optional implementation, the third determination module includes

[0076] The seventh determination submodule is used to obtain the cathode radius and the number of electrolysis chambers, and determine the total sacrificial anode protection area based on the cathode radius and the number of electrolysis chambers;

[0077] An eighth determination submodule, configured to determine a total protection current based on a total sacrificial anode protection area and a current density distribution of a reverse current;

[0078] The ninth determination submodule is used to determine the sacrificial anode output current based on the cathode protection current distribution, and to determine the number of sacrificial anode modules based on the sacrificial anode output current and the total protection current.

[0079] In a fourth aspect, the present invention provides a computer device comprising: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the computer instructions to execute a method for suppressing reverse current in an alkaline water electrolysis cell according to the second aspect or any corresponding embodiment thereof.

[0080] In a fifth aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to cause a computer to execute a method for suppressing reverse current in an alkaline water electrolysis cell according to the second aspect or any corresponding embodiment thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0081] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0082] Figure 1 It is a schematic diagram based on the current flow during normal operation of an existing alkaline water electrolyzer;

[0083] Figure 2 It is a schematic diagram of reverse current during shutdown of an existing alkaline water electrolyzer;

[0084] Figure 3 It is a schematic diagram of the bipolar plate polarization voltage during normal operation of an existing alkaline water electrolyzer;

[0085] Figure 4 It is a schematic diagram of the bipolar plate polarization voltage during the shutdown period of an existing alkaline water electrolyzer;

[0086] Figure 5 is a schematic structural diagram of a sacrificial anode protection system for suppressing reverse current in an alkaline water electrolysis cell according to an embodiment of the present invention;

[0087] Figure 6 is a schematic flow chart of a method for suppressing reverse current in an alkaline water electrolysis cell according to an embodiment of the present invention;

[0088] Figure 7 is a schematic flow chart of another method for suppressing reverse current in an alkaline water electrolysis cell according to an embodiment of the present invention;

[0089] Figure 8 is a schematic flow chart of another method for suppressing reverse current in an alkaline water electrolysis cell according to an embodiment of the present invention;

[0090] Fig. 9 is a structural block diagram of a device for suppressing reverse current in an alkaline water electrolysis cell according to an embodiment of the present invention;

[0091] Fig.10 It is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0092] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0093] In order to solve the serious stability problem that may exist in the electrolytic cell under repeated startup and shutdown operation conditions, related technologies such as Figure 1 As shown, in a bipolar alkaline water electrolyzer, KOH (potassium hydroxide) electrolyte is transported to the anode and cathode chambers through an alkaline solution flow channel, and the electrolyte and hydrogen and oxygen are transported to the gas-liquid separation system through a gas flow channel; since nickel reserves are abundant and the price is relatively cheap, nickel mesh or nickel-based alloy is commonly used in industry as hydrogen and oxygen evolution electrodes to effectively reduce overpotential; when the electrolyzer maintains an external current supply, the cathode and anode meshes are in a reduced and oxidized state environment, respectively; as shown in FIG. Figure 2 As shown in the figure, when the alkaline water electrolyzer is shut down due to shutdown and the external current supply is cut off, due to the presence of electrolyte in the circulation and distribution channels, a certain degree of current immediately flows through the bipolar plates in the opposite direction to the current during normal electrolysis operation, where the potential distribution of normal operation and sudden shutdown is as shown in Figure 3 As shown, when the electrolysis circuit is turned on, the reverse current is 0; therefore, the polarization voltage η c and η a =0, η c represents the cathode side overpotential, η a represents the anode side overpotential, where

[0094] U 1,initial =U 2,initial =Φ m,a,t -Φ m,c,b =Φ m,a,b -Φ m,c,t =U0 (1)

[0095] In the above formula, U 1,initial It represents the voltage of electrolysis chamber 1 after electrolysis, U 2,initial represents the voltage of the electrolytic chamber 2 after electrolysis, Φ represents the internal voltage, m represents the bipolar plate side, a represents the anode side, t represents the terminal side, c represents the cathode side, Φ m,a,t Indicates the voltage inside the anode terminal, Φ m,c,b represents the voltage inside the cathode side, Φ m,a,b Indicates that Φ m,c,t Indicates that U0 represents the standard electrode potential difference between the anode and cathode, that is, the reverse electromotive force after electrolysis.

[0096] like Figure 4As shown, when the conduction circuit is closed, the reverse current flows. The reverse current occurs due to the potential difference on both sides of the bipolar plate. The calculation formula of the potential difference ΔU on both sides of the bipolar plate is as follows:

[0097] ΔU=Φs,c,b-Φs,a,b (2)

[0098] In the above formula, s represents the electrolyte, Φs,c,b represents the liquid junction voltage on the cathode side, and Φs,a,b represents the liquid junction voltage on the anode side.

[0099] When reverse current exists, the open circuit voltage of the anode end battery gradually decreases to 0.3V (volts), while the voltage of the cathode end battery remains above 1.1V. A series of reactions will occur on the electrode surface: The reaction on the anode side is:

[0100] NiO2+H2O+e→NiOOH+OH- (3)

[0101] O2+H2O+4e→4OH- (4)

[0102] Among them, NiO2 represents nickel peroxide, H2O represents water, e represents electron, NiOOH represents nickel hydroxide, OH- represents hydroxide, and O2 represents oxygen.

[0103] The cathode side reaction is:

[0104] Ni+2OH-→Ni(OH)2+2e (5)

[0105] H2+OH-→H2O+2e (6)

[0106] Here, Ni represents nickel, Ni(OH)2 represents nickel hydroxide, and H2 represents hydrogen.

[0107] The reverse current of electrons flows through the bipolar plate only through the electrolyte; because the bipolar plate is electrically short-circuited between the two sides, the ions then pass through the bipolar plate to form a reverse loop, forming a galvanic cell that corrodes the cathode; because when the electrolyzer stops direct current, the solubility of oxygen in the anode liquid is large, and the solubility of hydrogen in the cathode liquid is small, and the hydrogen cannot complete the galvanic cell reaction with the cathode matrix and participate in the galvanic cell reaction, therefore, the anode active material of the bipolar plate will be reduced, and the cathode active material on the bipolar plate will be oxidized by the reverse current; finally, it is speculated that when the redox state on both sides of the bipolar plate is the same, the reverse current stops, and this process causes the nickel cathode to oxidize to form an irreversible β-Ni(OH)2 phase (a well-crystallized phase), resulting in a decrease in electrode performance and stability, and ultimately leading to a deterioration in the performance of the water electrolyzer system. With the continuous development of large-scale alkaline water electrolyzers, the number of small chambers in a single tank is gradually increased, and the accumulated value of reverse current also increases. In addition, when alkaline water electrolyzers are used for fluctuating operation of renewable energy, the damage of reverse current to the stable operation of the electrolyzer system may be accelerated.

[0108] Under the action of reverse current, the cathode coating will turn into hydroxide and lose its activity. Although the electrochemical stability of nickel-based electrodes can be improved by adding transition metal oxide coatings, the current coatings fail to fundamentally solve the problem, and partial detachment of the coating will cause electrolyte contamination.

[0109] According to an embodiment of the present invention, a sacrificial anode protection system for suppressing reverse current in an alkaline water electrolysis cell is provided. Figure 5 As shown, the system includes: a plurality of sacrificial anode modules 101; wherein the sacrificial anode module 101 includes an alkali tank 102 and a salt bridge 103;

[0110] The alkali box 102 contains alkali solution and is connected to the cathode terminal of the alkali water electrolysis cell through a wire;

[0111] The salt bridge 103 is connected to the alkaline water electrolysis cell and the alkaline tank 102 respectively, and is used to suppress the reverse current of the alkaline water electrolysis cell.

[0112] Specifically, an integrated or segmented sacrificial anode protection system is constructed according to the current distribution of the sacrificial anode module and the number of electrolysis chambers.

[0113] Furthermore, each group of sacrificial anode modules in the segmented sacrificial anode system includes an alkali tank 102 containing alkali solution of the same concentration, which is connected to the cathode of the bipolar plate by a wire, and a salt bridge 103 is bridged between the electrolytic cell and the external alkali tank to suppress the liquid junction potential.

[0114] Furthermore, the salt bridge 103 transports the alkali solution in the alkali tank 102 to the alkali solution channel, which is arranged at the alkali water electrolysis cell. The alkali solution in the alkali solution channel reacts chemically with the reverse current of the cathode terminal, thereby offsetting the reverse current.

[0115] Furthermore, the sacrificial anode protection system can be reasonably arranged according to the size of the alkaline water electrolysis cell and the size of the standard sacrificial anode.

[0116] Furthermore, before the alkaline water electrolyzer is shut down, the sacrificial anode wire needs to be connected in time, and when the reverse current of the electrolyzer stops and reaches equilibrium, the sacrificial anode wire needs to be cut off in time.

[0117] The present embodiment provides a sacrificial anode protection system for suppressing reverse current in an alkaline water electrolysis cell. A plurality of sacrificial anode modules are arranged outside the alkaline water electrolysis cell, and then the plurality of sacrificial anode modules are used to suppress oxidation of the cathode by the reverse current. This system does not pollute the alkaline solution in the alkaline water electrolysis cell, improves the stability of the alkaline water electrolysis cell under repeated startup and shutdown operation conditions, and extends the service life of the electrodes in the alkaline water electrolysis cell.

[0118] According to an embodiment of the present invention, a method embodiment of suppressing reverse current in an alkaline water electrolysis cell is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0119] In this embodiment, a method for suppressing reverse current in an alkaline water electrolysis cell is provided, and the sacrificial anode protection system for suppressing reverse current in an alkaline water electrolysis cell is applied. Figure 6 is a flow chart of a method for suppressing reverse current in an alkaline water electrolyzer according to an embodiment of the present invention. Figure 6 As shown, the process includes the following steps:

[0120] Step S601, obtaining the shutdown state data of the alkaline water electrolyzer, and based on the shutdown state data of the alkaline water electrolyzer, using the finite element method to determine the current density distribution and potential distribution of the cathode reverse current in the shutdown state of the alkaline water electrolyzer.

[0121] Specifically, during the immediate shutdown of the alkaline water electrolyzer, due to the differences in heat and mass transfer inside the alkaline water electrolyzer, the gas content and temperature of each electrolysis chamber are different. Therefore, the spatial distribution of the resistivity of the electrodes and electrolytes in multiple electrolysis chambers is not uniform, and the cathode potential distribution and reverse current density are different. Therefore, the finite element method is used to determine the current density distribution and potential distribution of the cathode reverse current when the alkaline water electrolyzer is in the shutdown state.

[0122] Step S602: selecting multiple types of metals as sacrificial anodes based on the Pourbaix diagram.

[0123] Specifically, the material used for the sacrificial anode is a metal that is more easily oxidized than Ni under alkaline conditions, selected based on the Bourbaix diagram, mainly including Cu (copper), Pb (lead), Sn (tin), Cd (cadmium), Fe (iron), Co (cobalt), Mn (manganese), Zn (zinc), Al (aluminum), Mg (magnesium), or alloys or oxides of the above metals.

[0124] Step S603, obtaining sacrificial anode protection current data, and determining the cathode protection potential distribution and cathode protection current distribution of the alkaline water electrolysis cell by using the finite element method based on the sacrificial anode protection current data.

[0125] Specifically, the protection range of sacrificial anodes of different types and qualities is determined by the cathodic protection potential distribution of the alkaline water electrolyzer, and then the type of sacrificial anode is determined based on the protection range of the sacrificial anode and the potential distribution of the reverse current, to ensure that the arrangement of the sacrificial anode meets the potential uniformity, and can completely offset the damage of the reverse current to the cathode of the alkaline electrolyzer, and prevent the occurrence of over-protection and under-protection.

[0126] Step S604, determining the number of sacrificial anode modules based on the current density distribution and potential distribution of the cathode reverse current and the cathode protection potential distribution and cathode protection current distribution of the alkaline water electrolyzer.

[0127] Specifically, the number of sacrificial anode modules is determined based on the current density distribution and potential distribution of the cathode reverse current and the cathodic protection potential distribution and cathodic protection current distribution of the alkaline water electrolyzer to ensure the protection potential and current range and prevent over-protection and under-protection.

[0128] Step S605 , constructing a sacrificial anode protection system at the alkaline water electrolysis cell based on the number of sacrificial anode modules to suppress reverse current in the alkaline water electrolysis cell.

[0129] The present embodiment provides a method for suppressing reverse current in an alkaline water electrolyzer. The current density distribution and potential distribution of the cathode reverse current in the shutdown state of the alkaline water electrolyzer are simulated, and a sacrificial anode is selected to simulate the cathodic protection potential distribution and cathodic protection current distribution of the sacrificial anode in the alkaline water electrolyzer, so as to ensure that the selected sacrificial anode distribution satisfies the uniformity of potential and current density, and completely offsets the damage of the reverse current to the cathode of the alkaline electrolyzer, prevents over-protection and under-protection, improves the stability of the alkaline water electrolyzer under repeated startup and shutdown operation conditions, and prolongs the service life of the electrodes in the alkaline water electrolyzer.

[0130] In this embodiment, a method for suppressing the reverse current of an alkaline water electrolyzer is provided, such as Figure 7 As shown, the sacrificial anode protection system can be used for suppressing the reverse current of the alkaline water electrolysis cell. Figure 7 is a flow chart of a method for suppressing reverse current in an alkaline water electrolyzer according to an embodiment of the present invention. Figure 7 As shown, the process includes the following steps:

[0131] Step S701, obtaining the shutdown state data of the alkaline water electrolyzer, and based on the shutdown state data of the alkaline water electrolyzer, using the finite element method to determine the current density distribution and potential distribution of the cathode reverse current in the shutdown state of the alkaline water electrolyzer.

[0132] Specifically, the above step S701 includes:

[0133] Step S7011, determining the resistivity, scalar potential and potential flux of the reverse current in the alkaline water electrolysis cell based on the shutdown state data of the alkaline water electrolysis cell.

[0134] Step S7012, constructing the conductivity differential equation of the alkaline water electrolyzer based on the resistivity, scalar potential and potential flux of the reverse current.

[0135] Specifically, since the current field generated by the reverse current in the alkaline water electrolyzer is an electrostatic field, the conductive differential equation of the bipolar plate in the three-dimensional direction is expressed by the Laplace equation as follows:

[0136]

[0137] Among them, ρ x Represents the resistivity of the reverse current in the x-axis direction, ρ y Represents the resistivity of the reverse current in the y-axis direction, ρ z Represents the resistivity of the reverse current in the z-axis direction, Φ x represents the scalar potential of the reverse current in the x-axis direction, Φ y represents the scalar potential of the reverse current in the y-axis direction, Φ z represents the scalar potential of the reverse current in the z-axis direction, represents the potential flux of the reverse current in the x-axis direction, represents the potential flux of the reverse current in the y-axis direction, Represents the potential flux of the reverse current in the z-axis direction.

[0138] Furthermore, the calculation formula of the scalar potential Φ of the reverse current in the three-dimensional direction is as follows:

[0139] ∑Φ=∑I r R (8)

[0140] In the above formula, I r represents reverse current, and R represents resistance.

[0141] Step S7013, obtaining the boundary conditions of the potential surface of the inlet and outlet of the alkali solution and the polarization curve of the bipolar plate, and determining the node potential of the alkaline water electrolyzer based on the conductive differential equation, the boundary conditions of the potential surface of the inlet and outlet of the alkali solution and the polarization curve of the bipolar plate.

[0142] In some optional implementations, the above step S7013 includes:

[0143] Step a1, dividing the area formed by the electrolytic cell anode, bipolar plates and electrolytic cell cathode in the alkaline water electrolyzer into multiple unit areas and multiple nodes; wherein the number of nodes is the same as the number of electrolysis chambers in the electric field of the alkaline water electrolyzer.

[0144] Specifically, the original cell formed by the anode, bipolar plate and cathode of the electrolytic cell in the solution area is meshed, and the area is divided into E unit areas and n nodes. When a reverse current is applied at the n nodes, the electric field of the alkaline water electrolyzer will be discretized into Φ l , Φ l =Φ1,Φ2,...Φ n , Φ lIt represents the potential to be determined of n electrolytic chambers (i.e. the node potential of n alkaline water electrolysis cells).

[0145] Step a2, interpolating the scalar potential of the reverse current based on the undetermined potentials of multiple nodes to generate a three-dimensional electric field definition domain.

[0146] Specifically, the three-dimensional electric field domain The expression is as follows:

[0147]

[0148] Step a3, constructing a weight function based on the undetermined potentials of multiple nodes and the three-dimensional electric field definition domain.

[0149] Specifically, according to the selection method of the weight function by the Galerkin method, the weight function W is obtained. l The calculation formula is as follows:

[0150]

[0151] Step a4, based on the three-dimensional electric field definition domain and the weight function, the conductive differential equation is converted into a boundary integral equation using the weighted residual method.

[0152] Specifically, the boundary integral equation is as follows:

[0153]

[0154] Step a5, constructing a matrix equation using the finite element method based on the boundary integral equation, the boundary conditions of the alkali solution inlet and outlet potential surfaces, and the bipolar plate polarization curve.

[0155] Specifically, the bipolar plate polarization curve represents the relationship between the reverse current density and the potential, and the bipolar plate polarization curve is expressed by the following formula:

[0156] Φ=X+I r R (12)

[0157] Where X represents the cumulative overpotential of the cathode reaction, I r R represents the ohmic polarization of the cathode internal resistance.

[0158] Furthermore, the above boundary integral is linked to the volume integral in the region, and the boundary conditions are introduced to form the following Gaussian formula:

[0159]

[0160] Wherein, J represents the current density, and α, β, and γ represent the angles between the potential of the reverse current and the three-dimensional coordinates.

[0161] Furthermore, the overall finite element equation is:

[0162]

[0163] Wherein, e represents the unit area.

[0164] Furthermore, for the n nodes corresponding to the E unit areas, the matrix equations are constructed using the above equations (13) and (14) as follows:

[0165] [k] e {Φ l} e =[f p ] e (15)

[0166] Where, [k] e is the unit current density matrix, {Φ l} e is the unit potential array, [f p ] e is the unit electric field matrix.

[0167] Step a6, constructing an alkaline water electrolyzer shutdown potential distribution model based on the matrix equation and the boundary conditions of the alkali solution inlet and outlet potential surfaces.

[0168] Specifically, the boundary condition of the alkali solution inlet and outlet potential surfaces is to set the alkali solution outlet as a high potential surface and the alkali solution inlet as a reference zero potential surface.

[0169] Step a7, iteratively solving the shutdown potential distribution model of the alkaline water electrolyzer to generate the node potential of the alkaline water electrolyzer.

[0170] Specifically, the scalar potential of each alkaline water electrolysis cell node can be obtained through iterative solution.

[0171] In the above optional implementation manner, by constructing an alkaline water electrolyzer shutdown potential distribution model and iteratively solving the alkaline water electrolyzer shutdown potential distribution model, the alkaline water electrolyzer node potential is generated, thereby improving the simulation accuracy of the alkaline water electrolyzer node potential.

[0172] Step S7014, determining the current density distribution and potential distribution of the cathode reverse current when the alkaline water electrolysis cell is in a shutdown state based on the node potential of the alkaline water electrolysis cell.

[0173] In some optional implementations, the above step S7014 includes:

[0174] Step b1, determining the potential distribution of the reverse current based on the node potential of the alkaline water electrolyzer.

[0175] Specifically, the node potential of the alkaline water electrolyzer represents the potential corresponding to each node, and then the potential distribution of the reverse current is determined based on the potential corresponding to each node.

[0176] Step b2, determining the relationship between current density and potential based on the bipolar plate polarization curve.

[0177] Step b3, based on the potential distribution of the reverse current, determine the current density distribution of the reverse current by utilizing the relationship between the current density and the potential.

[0178] In the above optional implementation manner, the current density distribution and potential distribution of the cathode reverse current in the shutdown state of the alkaline water electrolyzer are accurately simulated by the bipolar plate polarization curve.

[0179] Step S702: Select multiple types of metals as sacrificial anodes based on the Pourbaix diagram. Figure 6 Step S602 of the illustrated embodiment will not be described in detail here.

[0180] Step S703, obtaining sacrificial anode protection current data, and using the finite element method to determine the cathodic protection potential distribution and cathodic protection current distribution of the alkaline water electrolyzer based on the sacrificial anode protection current data. Figure 6 Step S603 of the illustrated embodiment will not be described in detail here.

[0181] Step S704, determining the number of sacrificial anode modules based on the current density distribution and potential distribution of the cathode reverse current and the cathode protection potential distribution and cathode protection current distribution of the alkaline water electrolyzer. Figure 6 Step S604 of the illustrated embodiment will not be described in detail here.

[0182] Step S705: construct a sacrificial anode protection system at the alkaline water electrolysis cell based on the number of sacrificial anode modules to suppress the reverse current of the alkaline water electrolysis cell. Figure 6 Step S605 of the illustrated embodiment will not be described in detail here.

[0183] The present embodiment provides a method for suppressing the reverse current of an alkaline water electrolyzer. The node potential of the alkaline water electrolyzer is determined based on the conductive differential equation, the boundary conditions of the alkali solution inlet and outlet potential surfaces, and the bipolar plate polarization curve. The potential of each unit node of the alkaline water electrolyzer is simulated, thereby achieving accurate simulation of the current density distribution and potential distribution of the cathode reverse current when the alkaline water electrolyzer is in the shutdown state.

[0184] In this embodiment, a method for suppressing reverse current in an alkaline water electrolysis cell is provided, which can be used in the sacrificial anode protection system for suppressing reverse current in an alkaline water electrolysis cell. Figure 8 is a flow chart of a method for suppressing reverse current in an alkaline water electrolyzer according to an embodiment of the present invention. Figure 8 As shown, the process includes the following steps:

[0185] Step S801, obtain the shutdown state data of the alkaline water electrolyzer, and determine the current density distribution and potential distribution of the cathode reverse current in the shutdown state of the alkaline water electrolyzer using the finite element method based on the shutdown state data of the alkaline water electrolyzer. Figure 7 Step S701 of the illustrated embodiment will not be described in detail here.

[0186] Step S802: Select multiple types of metals as sacrificial anodes based on the Pourbaix diagram. Figure 7 Step S702 of the illustrated embodiment will not be described in detail here.

[0187] Step S803, obtaining sacrificial anode protection current data, and determining the cathode protection potential distribution and cathode protection current distribution of the alkaline water electrolysis cell by using the finite element method based on the sacrificial anode protection current data.

[0188] Specifically, the above step S803 includes:

[0189] Step S8031, determining the scalar potential and potential flux of the sacrificial anode based on the sacrificial anode protection current data.

[0190] Step S8032, obtaining the resistivity, scalar potential and potential flux of the sacrificial anode protection current, and constructing the sacrificial anode conductivity differential equation based on the resistivity, scalar potential and potential flux of the sacrificial anode protection current.

[0191] Specifically, the construction steps of the sacrificial anode conductivity differential equation are the same as those of the alkaline water electrolyzer conductivity differential equation described above.

[0192] Step S8033, obtaining the polarization relationship between current density and potential and electrode boundary conditions, and determining the sacrificial anode node potential based on the sacrificial anode conductivity differential equation, the polarization relationship between current density and potential and electrode boundary conditions.

[0193] Specifically, the expression of the polarization relationship f(U) between current density and potential is as follows:

[0194]

[0195] Among them, ρ represents the resistivity of the electrolyte and the connecting wire in the sacrificial anode system, which is mainly affected by factors such as electrolyte concentration, temperature, and bubble rate. represents the normal component of the voltage, N represents the direction of the boundary normal, and U represents the scalar potential of the sacrificial anode protection current.

[0196] Furthermore, the electrode boundary conditions include:

[0197]

[0198]

[0199] Among them, i in is the input current density. When far away from the electrolytic cell, the electric field has little effect on the current and the current tends to 0. The current inflow occurring at the electrode boundary satisfies the above equation (17). The relationship between the current density and the potential satisfies the above equation (18).

[0200] Furthermore, the relationship between current density and potential is determined by measuring the polarization curves of the cathode and sacrificial anode of the electrolytic cell. Because the temperature and electrolyte gas content in different intervals of the electrolytic cell are different, the cathode polarization curves in different areas of the electrolytic cell are piecewise linearly fitted to obtain the relationship between the current density i in different potential intervals:

[0201] i=a+blogU (19)

[0202] Among them, a and b represent coefficients.

[0203] Further, the determination of the sacrificial anode node potential is the same as that of the alkaline water electrolyzer node potential described above.

[0204] Step S8034, determining the cathode protection potential distribution and cathode protection current distribution of the alkaline water electrolysis cell based on the sacrificial anode node potential.

[0205] Step S804, determining the number of sacrificial anode modules based on the current density distribution and potential distribution of the cathode reverse current and the cathode protection potential distribution and cathode protection current distribution of the alkaline water electrolyzer.

[0206] Specifically, the above step S804 includes:

[0207] Step S8041, obtaining the cathode radius and the number of electrolysis chambers, and determining the total sacrificial anode protection area based on the cathode radius and the number of electrolysis chambers.

[0208] Specifically, the calculation formula of the total sacrificial anode protection area S is as follows:

[0209] S=nπr 2 (20)

[0210] In the above formula, n represents the number of electrolytic chambers and r represents the cathode radius.

[0211] Step S8042, determining the total protection current based on the total protection area of ​​the sacrificial anode and the current density distribution of the reverse current.

[0212] Specifically, the alkaline water electrolyzer is divided into three parts: the liquid inlet section, the middle section and the liquid outlet section. The maximum protection current density i of each section of the electrolyzer is determined based on the current density distribution of the reverse current. max(1，2,3) , and the total protection current I t(1,2,3) The calculation formula is as follows:

[0213] I t(1,2,3) =S×i max(1，2,3) (twenty one)

[0214] Step S8043, determining the sacrificial anode output current based on the cathode protection current distribution, and determining the number of sacrificial anode modules based on the sacrificial anode output current and the total protection current.

[0215] Specifically, the calculation formula for the number M of sacrificial anode modules is as follows:

[0216]

[0217] In the above formula, I a It represents the output current of a single set of sacrificial anodes, and σ represents the backup factor, which is generally 3 times.

[0218] Step S805: construct a sacrificial anode protection system at the alkaline water electrolysis cell based on the number of sacrificial anode modules to suppress the reverse current of the alkaline water electrolysis cell. Figure 7 Step S705 of the illustrated embodiment will not be described in detail here.

[0219] This embodiment provides a method for suppressing reverse current in an alkaline water electrolysis cell. The number of sacrificial anode modules is determined based on the sacrificial anode output current and the total protection current, thereby ensuring that the sacrificial anode output current can completely offset the damage to the cathode of the alkaline electrolysis cell caused by the reverse current, thereby preventing over-protection and under-protection.

[0220] This embodiment provides a device for suppressing reverse current in an alkaline water electrolysis cell, such as Fig. 9 As shown, including:

[0221] The first determination module 901 is used to obtain the shutdown state data of the alkaline water electrolyzer, and determine the current density distribution and potential distribution of the cathode reverse current in the shutdown state of the alkaline water electrolyzer by using the finite element method based on the shutdown state data of the alkaline water electrolyzer;

[0222] A selection module 902 is used to select multiple types of metals as sacrificial anodes based on the Bourbaix diagram;

[0223] The second determination module 903 is used to obtain sacrificial anode protection current data, and determine the cathode protection potential distribution and cathode protection current distribution of the alkaline water electrolyzer by using the finite element method based on the sacrificial anode protection current data;

[0224] A third determination module 904 is used to determine the number of sacrificial anode modules based on the current density distribution and potential distribution of the cathode reverse current and the cathode protection potential distribution and cathode protection current distribution of the alkaline water electrolyzer;

[0225] The construction module 905 is used to construct a sacrificial anode protection system at the alkaline water electrolysis cell based on the number of sacrificial anode modules to suppress the reverse current of the alkaline water electrolysis cell.

[0226] In some optional implementations, the first determining module 901 includes:

[0227] A first determination submodule is used to determine the resistivity, scalar potential and potential flux of the reverse current in the alkaline water electrolyzer based on the shutdown state data of the alkaline water electrolyzer;

[0228] A first construction submodule is used to construct an alkaline water electrolyzer conductivity differential equation based on the resistivity, scalar potential and potential flux of the reverse current;

[0229] The second determination submodule is used to obtain the boundary conditions of the potential surface of the inlet and outlet of the alkali solution and the polarization curve of the bipolar plate, and determine the node potential of the alkaline water electrolyzer based on the conductive differential equation, the boundary conditions of the potential surface of the inlet and outlet of the alkali solution and the polarization curve of the bipolar plate;

[0230] The third determination submodule is used to determine the current density distribution and potential distribution of the cathode reverse current in the shutdown state of the alkaline water electrolyzer based on the node potential of the alkaline water electrolyzer.

[0231] In some optional implementations, the second determining submodule includes:

[0232] A division unit is used to divide the area formed by the electrolytic cell anode, bipolar plate and electrolytic cell cathode in the alkaline water electrolyzer into a plurality of unit areas and a plurality of nodes; wherein the number of nodes is the same as the number of electrolytic cells in the electric field of the alkaline water electrolyzer;

[0233] A difference unit is used to interpolate the scalar potential of the reverse current based on the potentials to be determined at multiple nodes to generate a three-dimensional electric field definition domain;

[0234] A first construction unit is used to construct a weight function based on the undetermined potentials of multiple nodes and a three-dimensional electric field definition domain;

[0235] A conversion unit, used for converting the conductive differential equation into a boundary integral equation by using a weighted residual method based on a three-dimensional electric field definition domain and a weight function;

[0236] The second construction unit is used to construct a matrix equation using a finite element method based on a boundary integral equation, boundary conditions of the alkali solution inlet and outlet potential surfaces, and a bipolar plate polarization curve;

[0237] The third construction unit is used to construct a shutdown potential distribution model of the alkaline water electrolyzer based on the matrix equation and the boundary conditions of the potential surface of the alkali solution inlet and outlet;

[0238] The iterative solution unit is used for iteratively solving the shutdown potential distribution model of the alkaline water electrolysis cell to generate the node potential of the alkaline water electrolysis cell.

[0239] In some optional implementations, the third determining submodule includes:

[0240] A first determining unit, configured to determine a potential distribution of a reverse current based on a node potential of an alkaline water electrolyzer;

[0241] a second determination unit, configured to determine a relationship between current density and potential based on a bipolar plate polarization curve;

[0242] The third determining unit is configured to determine the current density distribution of the reverse current based on the potential distribution of the reverse current by utilizing the relationship between the current density and the potential.

[0243] In some optional implementations, the second determining module 903 includes:

[0244] A fourth determination submodule, used to determine the scalar potential and potential flux of the sacrificial anode based on the sacrificial anode protection current data;

[0245] The second construction submodule is used to obtain the resistivity, scalar potential and potential flux of the sacrificial anode protection current, and construct the sacrificial anode conductive differential equation based on the resistivity, scalar potential and potential flux of the sacrificial anode protection current;

[0246] A fifth determination submodule is used to obtain the polarization relationship between current density and potential and the electrode boundary conditions, and determine the sacrificial anode node potential based on the sacrificial anode conductivity differential equation, the polarization relationship between current density and potential and the electrode boundary conditions;

[0247] The sixth determination submodule is used to determine the cathodic protection potential distribution and the cathodic protection current distribution of the alkaline water electrolyzer based on the sacrificial anode node potential.

[0248] In some optional implementations, the third determining module 904 includes

[0249] The seventh determination submodule is used to obtain the cathode radius and the number of electrolysis chambers, and determine the total sacrificial anode protection area based on the cathode radius and the number of electrolysis chambers;

[0250] An eighth determination submodule, configured to determine a total protection current based on a total sacrificial anode protection area and a current density distribution of a reverse current;

[0251] The ninth determination submodule is used to determine the sacrificial anode output current based on the cathode protection current distribution, and to determine the number of sacrificial anode modules based on the sacrificial anode output current and the total protection current.

[0252] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0253] In this embodiment, a device for obtaining a network card data signal is presented in the form of a functional unit, where the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that executes one or more software or fixed programs, and / or other devices that can provide the above functions.

[0254] The embodiment of the present invention also provides a computer device having the above Fig. 9 A device for suppressing reverse current in an alkaline water electrolysis cell is shown.

[0255] See also Fig.10 , Fig.10 is a schematic diagram of the structure of a computer device provided by an optional embodiment of the present invention, such as Fig.10 As shown, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components are connected to each other using different buses for communication, and can be installed on a common mainboard or installed in other ways as needed. The processor can process the instructions executed in the computer device, including instructions stored in or on the memory to display the graphical information of the GUI on an external input / output device (such as, a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Fig.10 A processor 10 is taken as an example.

[0256] The processor 10 may be a central processing unit, a network processor or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic or any combination thereof.

[0257] The memory 20 stores instructions executable by at least one processor 10, so that the at least one processor 10 executes the method shown in the above embodiment.

[0258] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created according to the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely arranged relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0259] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid state drive; the memory 20 may also include a combination of the above types of memory.

[0260] The computer device also includes an input device 30 and an output device 40. The processor 10, the memory 20, the input device 30 and the output device 40 may be connected via a bus or other means. Fig.10 The example of connecting through bus is taken in the following.

[0261] The input device 30 can receive input digital or character information, and generate key signal input related to the user settings and function control of the computer device, such as a touch screen, a keypad, a mouse, a track pad, a touch pad, an indicator bar, one or more mouse buttons, a trackball, a joystick, etc. The output device 40 may include a display device, an auxiliary lighting device (e.g., an LED) and a tactile feedback device (e.g., a vibration motor), etc. The above-mentioned display device includes but is not limited to a liquid crystal display, a light emitting diode, a display and a plasma display. In some optional embodiments, the display device can be a touch screen.

[0262] The embodiment of the present invention also provides a computer-readable storage medium. The method according to the embodiment of the present invention can be implemented in hardware, firmware, or can be implemented as a computer code that can be recorded in a storage medium, or can be implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and will be stored in a local storage medium through a network download, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state hard disk, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor, or hardware, the method shown in the above embodiment is implemented.

[0263] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A method for suppressing reverse current in an alkaline water electrolyzer, characterized in that: A sacrificial anode protection system for suppressing reverse current in an alkaline water electrolysis cell is applied, the system comprising: a plurality of sacrificial anode modules; wherein the sacrificial anode modules comprise an alkali box and a salt bridge; the alkali box contains alkali solution and is connected to the cathode terminal of the alkaline water electrolysis cell through a wire; the salt bridge is connected to the alkaline water electrolysis cell and the alkali box respectively, and is used to suppress reverse current in the alkaline water electrolysis cell; the method comprises: Acquire shutdown state data of the alkaline water electrolyzer, and determine the current density distribution and potential distribution of the cathode reverse current in the shutdown state of the alkaline water electrolyzer by using a finite element method based on the shutdown state data of the alkaline water electrolyzer; Select various types of metals as sacrificial anodes based on the Bourbaix diagram; Acquire sacrificial anode protection current data, and determine the cathodic protection potential distribution and cathodic protection current distribution of the alkaline water electrolyzer using a finite element method based on the sacrificial anode protection current data; Determining the number of sacrificial anode modules based on the current density distribution and potential distribution of the cathode reverse current and the cathodic protection potential distribution and cathodic protection current distribution of the alkaline water electrolyzer; A sacrificial anode protection system is constructed at the alkaline water electrolysis cell based on the number of the sacrificial anode modules to suppress reverse current in the alkaline water electrolysis cell.

2. The method according to claim 1, characterized in that: The method of determining the current density distribution and potential distribution of the cathode reverse current in the shutdown state of the alkaline water electrolyzer by using the finite element method based on the shutdown state data of the alkaline water electrolyzer comprises: Determining the resistivity, scalar potential and potential flux of the reverse current in the alkaline water electrolyzer based on the shutdown state data of the alkaline water electrolyzer; constructing an alkaline water electrolyzer conductivity differential equation based on the resistivity, scalar potential and potential flux of the reverse current; Obtaining boundary conditions of the potential surface of the inlet and outlet of the alkali solution and the polarization curve of the bipolar plate, and determining the node potential of the alkaline water electrolyzer based on the conductive differential equation, the boundary conditions of the potential surface of the inlet and outlet of the alkali solution and the polarization curve of the bipolar plate; The current density distribution and potential distribution of the cathode reverse current in the alkaline water electrolyzer in a shutdown state are determined based on the node potential of the alkaline water electrolyzer.

3. The method according to claim 2, characterized in that The determining of the node potential of the alkaline water electrolyzer based on the conductive differential equation, the boundary conditions of the alkali solution inlet and outlet potential surfaces and the bipolar plate polarization curve comprises: Dividing the area formed by the electrolytic cell anode, bipolar plates and electrolytic cell cathode in the alkaline water electrolyzer into a plurality of unit areas and a plurality of nodes; wherein the number of nodes is the same as the number of electrolytic cells in the electric field of the alkaline water electrolyzer; The scalar potential of the reverse current is interpolated based on the undetermined potentials of multiple nodes to generate a three-dimensional electric field definition domain; Constructing a weight function based on the undetermined potentials of the plurality of nodes and the three-dimensional electric field definition domain; Based on the three-dimensional electric field definition domain and the weight function, converting the conductive differential equation into a boundary integral equation using a weighted residual method; Based on the boundary integral equation, the boundary conditions of the alkali solution inlet and outlet potential surfaces and the bipolar plate polarization curve, a matrix equation is constructed using the finite element method; Constructing a shutdown potential distribution model of an alkaline water electrolyzer based on the matrix equation and the boundary conditions of the alkali solution inlet and outlet potential surfaces; The shutdown potential distribution model of the alkaline water electrolyzer is iteratively solved to generate the node potential of the alkaline water electrolyzer.

4. The method according to claim 2, characterized in that: The method of determining the current density distribution and potential distribution of the cathode reverse current in the alkaline water electrolyzer in a shutdown state based on the node potential of the alkaline water electrolyzer comprises: Determining the potential distribution of the reverse current based on the node potential of the alkaline water electrolyzer; Determining the relationship between current density and potential based on the bipolar plate polarization curve; Based on the potential distribution of the reverse current, the current density distribution of the reverse current is determined using the relationship between the current density and the potential.

5. The method according to claim 2, characterized in that: The method of determining the cathodic protection potential distribution and the cathodic protection current distribution of the alkaline water electrolyzer by using the finite element method based on the sacrificial anode protection current data includes: Determining a scalar potential and a potential flux of a sacrificial anode based on the sacrificial anode protection current data; Obtaining the resistivity, scalar potential and potential flux of the sacrificial anode protection current, and constructing a sacrificial anode conductivity differential equation based on the resistivity, scalar potential and potential flux of the sacrificial anode protection current; Obtaining the polarization relationship between current density and potential and electrode boundary conditions, and determining the sacrificial anode node potential based on the sacrificial anode conductivity differential equation, the polarization relationship between current density and potential and the electrode boundary conditions; The cathodic protection potential distribution and the cathodic protection current distribution of the alkaline water electrolysis cell are determined based on the sacrificial anode node potential.

6. The method according to claim 1, characterized in that The method of determining the number of sacrificial anode modules based on the current density distribution and potential distribution of the cathode reverse current and the cathode protection potential distribution and cathode protection current distribution of the alkaline water electrolyzer comprises: Acquire the cathode radius and the number of electrolysis chambers, and determine the total sacrificial anode protection area based on the cathode radius and the number of electrolysis chambers; Determining a total protection current based on the total protection area of ​​the sacrificial anode and the current density distribution of the reverse current; The sacrificial anode output current is determined based on the cathodic protection current distribution, and the number of the sacrificial anode modules is determined based on the sacrificial anode output current and the total protection current.

7. A device for suppressing reverse current in an alkaline water electrolysis cell, characterized in that: include: A first determination module is used to obtain shutdown state data of the alkaline water electrolyzer, and based on the shutdown state data of the alkaline water electrolyzer, determine the current density distribution and potential distribution of the cathode reverse current in the shutdown state of the alkaline water electrolyzer by using a finite element method; A selection module, used to select various types of metals as sacrificial anodes based on the Bourbaix diagram; A second determination module is used to obtain sacrificial anode protection current data, and based on the sacrificial anode protection current data, determine the cathode protection potential distribution and cathode protection current distribution of the alkaline water electrolyzer by using a finite element method; A third determination module is used to determine the number of sacrificial anode modules based on the current density distribution and potential distribution of the cathode reverse current and the cathode protection potential distribution and cathode protection current distribution of the alkaline water electrolyzer; A building module is used to build a sacrificial anode protection system at the alkaline water electrolysis cell based on the number of the sacrificial anode modules to suppress reverse current in the alkaline water electrolysis cell.

8. The device according to claim 7, characterized in that The first determining module includes: A first determination submodule, configured to determine the resistivity, scalar potential and potential flux of the reverse current in the alkaline water electrolyzer based on the shutdown state data of the alkaline water electrolyzer; A first construction submodule is used to construct an alkaline water electrolyzer conductivity differential equation based on the resistivity, scalar potential and potential flux of the reverse current; The second determination submodule is used to obtain the boundary conditions of the alkali solution inlet and outlet potential surface and the bipolar plate polarization curve, and determine the node potential of the alkaline water electrolyzer based on the conductive differential equation, the boundary conditions of the alkali solution inlet and outlet potential surface and the bipolar plate polarization curve; The third determination submodule is used to determine the current density distribution and potential distribution of the cathode reverse current in the shutdown state of the alkaline water electrolyzer based on the node potential of the alkaline water electrolyzer.

9. The device according to claim 8, characterized in that The second determining submodule includes: A division unit is used to divide the area formed by the electrolytic cell anode, bipolar plate and electrolytic cell cathode in the alkaline water electrolyzer into a plurality of unit areas and a plurality of nodes; wherein the number of nodes is the same as the number of electrolytic cells in the electric field of the alkaline water electrolyzer; A difference unit, used for interpolating the scalar potential of the reverse current based on the potentials to be determined at multiple nodes to generate a three-dimensional electric field definition domain; A first construction unit is used to construct a weight function based on the potentials to be determined of the plurality of nodes and the three-dimensional electric field definition domain; A conversion unit, configured to convert the conductive differential equation into a boundary integral equation by using a weighted residual method based on the three-dimensional electric field definition domain and the weight function; A second construction unit is used to construct a matrix equation using the finite element method based on the boundary integral equation, the boundary conditions of the alkali solution inlet and outlet potential surfaces and the bipolar plate polarization curve; A third construction unit is used to construct a shutdown potential distribution model of the alkaline water electrolyzer based on the matrix equation and the boundary conditions of the alkali solution inlet and outlet potential surfaces; The iterative solution unit is used to iteratively solve the shutdown potential distribution model of the alkaline water electrolysis cell to generate the node potential of the alkaline water electrolysis cell.

10. The device according to claim 8, characterized in that The third determining submodule includes: A first determining unit, configured to determine a potential distribution of the reverse current based on a node potential of the alkaline water electrolyzer; a second determining unit, configured to determine a relationship between current density and potential based on the bipolar plate polarization curve; The third determining unit is configured to determine the current density distribution of the reverse current based on the potential distribution of the reverse current and by utilizing the relationship between the current density and the potential.

11. The device according to claim 8, characterized in that The second determining module includes: a fourth determination submodule, configured to determine a scalar potential and a potential flux of a sacrificial anode based on the sacrificial anode protection current data; A second construction submodule is used to obtain the resistivity, scalar potential and potential flux of the sacrificial anode protection current, and to construct a sacrificial anode conduction differential equation based on the resistivity, scalar potential and potential flux of the sacrificial anode protection current; a fifth determination submodule, configured to obtain a polarization relationship between current density and potential and an electrode boundary condition, and determine a sacrificial anode node potential based on the sacrificial anode conduction differential equation, the polarization relationship between current density and potential and the electrode boundary condition; The sixth determination submodule is used to determine the cathodic protection potential distribution and the cathodic protection current distribution of the alkaline water electrolyzer based on the sacrificial anode node potential.

12. The device according to claim 7, characterized in that The third determination module includes A seventh determination submodule is used to obtain the cathode radius and the number of electrolysis chambers, and determine the total sacrificial anode protection area based on the cathode radius and the number of electrolysis chambers; An eighth determination submodule, configured to determine a total protection current based on the total sacrificial anode protection area and the current density distribution of the reverse current; A ninth determination submodule is used to determine the sacrificial anode output current based on the cathode protection current distribution, and to determine the number of the sacrificial anode modules based on the sacrificial anode output current and the total protection current.

13. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the method for suppressing reverse current in an alkaline water electrolysis cell according to any one of claims 1 to 6 by executing the computer instructions.

14. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the method for suppressing reverse current in an alkaline water electrolysis cell according to any one of claims 1 to 6.

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