CN-119069012-B - Energy flow modeling analysis method for alkaline water electrolysis hydrogen production system

CN119069012BCN 119069012 BCN119069012 BCN 119069012BCN-119069012-B

Abstract

The invention provides an energy flow modeling analysis method of an alkaline electrolyzed water hydrogen production system, which comprises the steps of defining reversible voltage and activation overvoltage as voltage sources based on an electrochemical reaction mechanism equation and ohm law aiming at a galvanic pile component, defining ohmic resistance according to ohm overvoltage by using an electrolysis cell as a unit, connecting different circuit elements to obtain an electrochemical energy flow model of the galvanic pile, establishing a heat transfer energy flow model of a gas-liquid separator, the galvanic pile component, a mixer and a heat exchanger, connecting nodes with the same temperature, establishing a system integral heat transfer energy flow model, and carrying out model solving according to the electrochemical energy flow model of the galvanic pile component, the system integral heat transfer energy flow model and corresponding constraint conditions by taking the ambient temperature and cold fluid inlet temperature as boundary conditions and combining system operation parameters and system structure parameters to obtain an operation analysis result of the alkaline electrolyzed water hydrogen production system. According to the energy flow modeling analysis method of the alkaline water electrolysis hydrogen production system, disclosed by the invention, the cross-scale unified modeling and analysis of the alkaline water electrolysis hydrogen production system are realized by establishing the heat transfer energy flow model of the external system and the electrochemical energy flow model of the internal process of the galvanic pile.

Inventors

CHEN QUN
HAO QIANPENG
He Kelun
LI QIANG
JIANG YICHONG
ZHANG YE
MA HUAN
MENG NAN
YAO SHUN

Assignees

清华大学
内蒙古电力(集团)有限责任公司

Dates

Publication Date: 20260512
Application Date: 20240723

Claims (9)

1. An energy flow modeling analysis method of an alkaline electrolyzed water hydrogen production system is characterized by comprising the following steps: For a galvanic pile component in an alkaline water electrolysis hydrogen production system, defining reversible voltage and activation overvoltage as voltage sources based on an electrochemical reaction mechanism equation and ohm law by taking an electrolysis cell as a unit, defining ohmic resistance according to ohm overvoltage, connecting different circuit elements to obtain an electrochemical energy flow model of the galvanic pile, and obtaining constraint conditions of the electrochemical energy flow model of the galvanic pile component according to kirchhoff law; Establishing a heat transfer energy flow model of a gas-liquid separator, a galvanic pile component, a mixer and a heat exchanger aiming at the alkaline electrolyzed water hydrogen production system, connecting nodes with the same temperature, establishing a system integral heat transfer energy flow model, and obtaining constraint conditions of the system integral heat transfer energy flow model according to kirchhoff's law, wherein the nodes comprise inlets and outlets of the gas-liquid separator, the galvanic pile component, the mixer and the heat exchanger; Taking the ambient temperature and the cold fluid inlet temperature as boundary conditions, and carrying out model solving according to an electrochemical energy flow model and corresponding constraint conditions of the galvanic pile component, an overall heat transfer energy flow model and corresponding constraint conditions of the system and combining system operation parameters and system structure parameters to obtain an operation analysis result of the alkaline water electrolysis hydrogen production system; the heat transfer energy flow model of the hydrogen separator in the gas-liquid separator is expressed as follows: ; ; Wherein, the Represents the corresponding thermodynamic potential in the fluid mixing process of the gas-liquid separator at the side of the hydrogen, Represents the temperature of the makeup water, the water transmitted by the oxygen separator and the original electrolyte of the hydrogen separator after being mixed, The temperature of the make-up water is indicated, The mass flow rate of the electrolyte is represented, Represents the specific heat capacity of the electrolyte, Represents the mass flow rate of water consumed by hydrogen side producing hydrogen, Indicating the temperature of the outlet of the stack, Indicating the temperature of the outlet of the oxygen separator, Indicating the mass flow rate of the generated hydrogen gas, Represents the specific heat capacity of the hydrogen gas, Represents the thermal resistance of the hydrogen separator to the heat dissipation of the environment, Indicating the amount of heat dissipated from the hydrogen separator and the environment, The product of the heat exchange coefficient and the heat exchange area of the gas-liquid separator and the heat dissipation of the environment is shown.
2. The method of energy flow modeling analysis of an alkaline water electrolysis hydrogen production system according to claim 1, wherein the reversible voltage is expressed as: ; Wherein, the Representing the said voltage of the said voltage converter, The standard quasi-reversible voltage is represented, Which represents the constant of the state of the gas, The temperature is indicated as a function of the temperature, The faraday constant is represented by a value, Indicating the operating pressure of the system, The partial pressure of water vapor is indicated, Represents water activity in the range of 0-150 degrees celsius; The activation overvoltage is expressed as: ; ; Wherein, the Indicating the cathode activation overvoltage, Indicating the positive electrode activation overvoltage, The cathode transfer coefficient is represented by the number of the electrodes, The transfer coefficient of the anode is indicated, The current density is indicated as such, Indicating the exchange current density of the cathode, Indicating the exchange current density of the anode, Representing the coverage of bubbles on the surface of the electrode; the ohmic overvoltage is expressed as: ; Wherein, the Representing the said ohmic overvoltage, Representing the resistance of the cathode electrode, Representing the resistance of the anode, The resistance of the electrolyte is indicated, Representing the resistance of the diaphragm, Indicating the given current in the electrolysis cell.
3. The method of energy flow modeling analysis of an alkaline water electrolysis hydrogen production system according to claim 1, wherein the heat transfer energy flow model of the galvanic pile component is expressed as: ; ; ; ; Wherein, the Indicating the amount of heat generated during the electrolysis process, Indicating the number of cells to be electrolyzed, Which is indicative of the cell voltage and, Which represents the thermal neutral voltage of the electric motor, Indicating that the electrolysis cell is given a current, Represents the thermal potential during the electrolysis process, Indicating the temperature of the stack after it has been heated by the heat generated during electrolysis, Indicating the temperature of the inlet of the stack, The mass flow rate of the electrolyte is represented, Represents the specific heat capacity of the electrolyte, Representing the thermal resistance of the heat dissipation process between the stack and the environment, The temperature of the make-up water is indicated, Indicating the amount of heat dissipated from the stack and the environment, Representing the product of the heat exchange coefficient and the heat exchange area of the electric pile and the environmental heat dissipation, Represents the thermal potential of the heat dissipation process between the galvanic pile and the environment, Indicating the stack outlet temperature.
4. The method for modeling and analyzing the energy flow of the alkaline water electrolysis hydrogen production system according to claim 1, wherein the heat transfer energy flow model of the oxygen separator in the gas-liquid separator is expressed as: ; ; Wherein, the Represents the thermal resistance of the oxygen separator to the heat dissipation of the environment, Indicating the temperature of the outlet of the stack, The temperature of the make-up water is indicated, Indicating the amount of heat dissipated from the oxygen separator to the environment, Represents the product of the heat exchange coefficient and the heat exchange area of the gas-liquid separator and the environmental heat dissipation, Represents the thermal potential of the oxygen separator and the heat dissipation of the environment, Indicating the temperature of the outlet of the oxygen separator, The mass flow rate of the electrolyte is represented, Represents the specific heat capacity of the electrolyte, Indicating the mass flow rate of the oxygen generated, Represents the specific heat capacity of oxygen, The mass flow of water consumed by hydrogen side hydrogen production is shown.
5. The method for modeling and analyzing the energy flow of an alkaline water electrolysis hydrogen production system according to claim 1, wherein the heat transfer energy flow model of the mixer is expressed as: ; Wherein, the The mixed thermal electromotive force is represented by the expression, The temperature of the electrolyte at the outlet of the hydrogen separator after being mixed with the electrolyte at the outlet of the oxygen separator is shown, Indicating the temperature of the outlet of the hydrogen separator, Indicating the temperature of the outlet of the oxygen separator, The mass flow rate of the electrolyte is represented, Representing the specific heat capacity of the electrolyte.
6. The method for modeling and analyzing the energy flow of the alkaline water electrolysis hydrogen production system according to claim 1, wherein the heat transfer energy flow model of the heat exchanger is expressed as: ; ; ; Wherein, the Representing the thermodynamic potential characterizing the change in temperature of the thermal fluid, The temperature of the electrolyte at the outlet of the hydrogen separator after being mixed with the electrolyte at the outlet of the oxygen separator is shown, Indicating the temperature of the inlet of the stack, The amount of heat exchange is indicated by the heat exchange amount, The mass flow rate of the electrolyte is represented, Represents the specific heat capacity of the electrolyte, Representing the thermal potential characterizing the change in temperature of the cold fluid, Indicating the temperature of the outlet of the cooling water, Indicating the temperature of the cooling water inlet, Indicating the mass flow rate of the cold fluid, Indicating the specific heat capacity of the cold fluid, Indicating the thermal resistance of the heat exchanger, Representing the hot volume flow of the cold fluid, Represents the flow of the heat capacity of the electrolyte, Indicating the number of heat transfer units of the hot fluid, The number of heat transfer units of the cold fluid is indicated.
7. The method for modeling and analyzing the energy flow of the alkaline water electrolysis hydrogen production system according to claim 1, wherein the method for modeling and analyzing the energy flow of the alkaline water electrolysis hydrogen production system by combining the system operation parameters and the system structure parameters comprises the following steps: Combining the cooling water flow, the electrolyte flow, the pressure and the current in the system operation parameters and combining the system structural parameters to obtain the node temperature and the working medium flow when the system operates; And/or the number of the groups of groups, Combining cooling water flow, pressure and current in system operation parameters and combining system structural parameters to obtain system operation analysis results of heat exchange quantity change of a heat exchanger, temperature change of a galvanic pile and cell voltage change along with the cooling water flow change; And/or the number of the groups of groups, Combining the cooling water flow, the electrolyte flow, the pressure and the current in the system operation parameters and combining the system structural parameters to obtain a system operation analysis result of the temperature change of the inlet and the outlet of the electric pile and the voltage change of the cell along with the increase of the electrolyte flow; And/or the number of the groups of groups, Combining the pressure in the system operation parameters, different stack temperatures and the system structural parameters to obtain a change curve of hydrogen production rate and voltage efficiency along with current density; And/or the number of the groups of groups, And combining the temperature and the pressure of the electric pile in the system operation parameters and combining the system structural parameters to obtain the polarization curve of the electric pile.
8. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor, when executing the program, implements the energy flow modeling analysis method of the alkaline water electrolysis hydrogen production system of any one of claims 1 to 7.
9. A non-transitory computer readable storage medium having stored thereon a computer program, wherein the computer program when executed by a processor implements the energy flow modeling analysis method of an alkaline water electrolysis hydrogen production system as claimed in any one of claims 1 to 7.

Description

Energy flow modeling analysis method for alkaline water electrolysis hydrogen production system Technical Field The invention relates to the technical field of hydrogen production by water electrolysis, in particular to an energy flow modeling analysis method of an alkaline water electrolysis hydrogen production system. Background The hydrogen energy is used as a green low-carbon secondary energy source with wide application, and plays an important role in assisting the consumption of renewable energy sources, realizing large-scale peak regulation of a power grid and energy storage across seasons and regions, and promoting low carbonization in the fields of industry, construction, traffic and the like. Compared with the hydrogen production by chemical reaction of fossil fuel, the electrolytic water hydrogen production has no carbon emission, can be combined with renewable energy power generation, provides assistance for renewable energy consumption, and is widely paid attention and paid attention at present. The electric hydrogen production can convert electric energy into chemical energy in hydrogen, and can provide flexible adjustment means for a novel electric power system, wherein the alkaline electrolysis water technology is mature, the process is simple, the cost is low, the alkaline electrolysis water hydrogen production method is a main mode of water electrolysis hydrogen production at present, the alkaline electrolysis can realize minute-scale response of input power, peak regulation and frequency modulation service is provided for a power grid, the safety, reliability and flexibility of the electric power system are improved, and the method has great significance for power grid regulation and control. However, the energy efficiency of the system is significantly affected by parameters such as the temperature of the stack. In addition, the system has multiple operation parameters, spans multiple time and space scales, has complex integral and trans-scale modeling and different electric and thermal mathematical properties, so that the integral model of the system presents high-dimensional and nonlinear implicit characteristics, and is difficult to integrally solve and analyze. Disclosure of Invention The invention provides an energy flow modeling analysis method of an alkaline water electrolysis hydrogen production system, which is used for solving the defect that the modeling solution and analysis of the alkaline water electrolysis hydrogen production system are difficult in the prior art and realizing the cross-scale unified modeling and analysis of the alkaline water electrolysis hydrogen production system. The invention provides an energy flow modeling analysis method of an alkaline electrolyzed water hydrogen production system, which comprises the steps of defining reversible voltage and activation overvoltage as voltage sources based on an electrochemical reaction mechanism equation and ohm law by taking an electrolysis cell as a unit, defining ohm resistance according to ohm overvoltage, connecting different circuit elements to obtain electrochemical energy flow models of a galvanic pile, obtaining constraint conditions of the electrochemical energy flow models of the galvanic pile according to kirchhoff law, establishing a heat transfer energy flow model of a gas-liquid separator, the galvanic pile component, a mixer and a heat exchanger for the alkaline electrolyzed water hydrogen production system, connecting nodes with the same temperature, establishing a system overall heat transfer energy flow model, obtaining constraint conditions of the system overall heat transfer energy flow model according to kirchhoff law, wherein the nodes comprise inlet and outlet of the gas-liquid separator, the galvanic pile component, the mixer and the heat exchanger, obtaining constraint conditions of the system overall heat transfer energy flow model according to the kirchhoff law, solving the constraint conditions of the system overall heat transfer energy flow model according to the constraint conditions of the galvanic pile component and the electrochemical energy flow model and the corresponding system operation parameters, and analyzing the constraint conditions of the system operation parameters. According to the energy flow modeling analysis method of the alkaline water electrolysis hydrogen production system provided by the invention, the reversible voltage is expressed as follows: Wherein, the Representing the said voltage of the said voltage converter,The standard quasi-reversible voltage is represented,Which represents the constant of the state of the gas,The temperature is indicated as a function of the temperature,The faraday constant is represented by a value,Indicating the operating pressure of the system,The partial pressure of water vapor is indicated,Represents water activity in the range of 0-150 degrees celsius; The activation overvoltage is expressed as: Wherein, the Indicating the ca