Dynamic optimization method and device for SOEC co-electrolysis

Abstract

The invention relates to a dynamic optimization method and device for SOEC co-electrolysis, and belongs to the technical field of solid oxide electrolysis, and the dynamic optimization method for SOEC co-electrolysis comprises the following steps: determining a working voltage equation of SOEC based on a gas volume ratio sum, a gas volume ratio sum, a reversible voltage sum and a reversible voltage; determining positive reaction constants of WGSR and DIR based on the stack temperature of the SOEC; determining a reaction rate equation of WGSR and DIR based on the pressure intensity of each reaction gas; an SOEC co-electrolysis model is constructed based on the working voltage equation of the SOEC and the reaction rate equation of the WGSR and the DIR, and a dynamic optimization strategy of the input voltage, the inlet gas component and the inlet gas temperature of SOEC co-electrolysis is determined based on the SOEC co-electrolysis model. According to the invention, the efficiency and the stability of SOEC co-electrolysis are effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solid oxide electrolysis, in particular to a dynamic optimization method and device for SOEC co-electrolysis. BACKGROUND

[0002] The energy storage technology taking solid oxide electrolysis cell (SOEC) as the core is an important path to realize efficient storage of renewable energy. SOEC can convert the electrical energy generated by renewable energy into chemical energy contained in H2 and CO by means of the co-electrolysis reaction of H2O and CO2 under high-temperature environment. and and

[0003] In the scenario of co-electrolysis technology and renewable energy coordination operation, the fluctuation of renewable energy output will force the SOEC co-electrolysis stack to be in a dynamic working condition for a long time, which poses a significant challenge to the performance of the stack. Under the dynamic working condition, the SOEC co-electrolysis efficiency is greatly affected, not only the efficiency is reduced, but also the efficiency presents a large fluctuation, which affects the stability of the system. The existing co-electrolysis research scheme only focuses on the steady-state characteristics of SOEC under specific working conditions, and it is difficult to adapt to the dynamic working condition in the actual scene.

[0004] Therefore, how to improve the efficiency and stability of SOEC co-electrolysis has become a technical problem to be solved. SUMMARY

[0005] Therefore, it is necessary to provide a dynamic optimization method and device for SOEC co-electrolysis to solve the problem of low efficiency and stability of the existing SOEC co-electrolysis scheme.

[0006] In order to solve the above problems, in a first aspect, the present application provides a dynamic optimization method for SOEC co-electrolysis, comprising: determining the reversible voltage of the SOEC based on the gas volume ratio of H2O and the gas volume ratio of CO2, and the reversible voltage of the SOEC based on the reversible voltage of the SOEC, the activation overpotential, the ohmic overpotential and the concentration overpotential, and determining the working voltage equation of the SOEC; determining the equilibrium constant of WGSR and DIR based on the stack temperature of the SOEC, and determining the forward reaction constant of WGSR and DIR based on the stack temperature of the SOEC and the ideal gas constant; determining the reversible voltage of the SOEC based on the gas volume ratio of H2O and the gas volume ratio of CO2, and the reversible voltage of the SOEC based on the reversible voltage of the SOEC, the activation overpotential, the ohmic overpotential and the concentration overpotential, and determining the working voltage equation of the SOEC; determining the equilibrium constant of WGSR and DIR based on the stack temperature of the SOEC, and determining the forward reaction constant of WGSR and DIR based on the stack temperature of the SOEC and the ideal gas constant; determining the reversible voltage of the SOEC based on the gas volume ratio of H2O and the gas volume ratio of CO2, and the reversible voltage of the SOEC based on the reversible voltage of the SOEC, the activation overpotential, the ohmic overpotential and the concentration overpotential, and determining the working voltage equation of the SOEC; determining the equilibrium constant of WGSR and DIR based on the stack temperature of the SOEC, and determining the forward reaction constant of WGSR and DIR based on the stack temperature of the SOEC and the ideal gas constant; ​​Based on the equilibrium constant, the positive reaction constant of the WGSR, the equilibrium constant, the positive reaction constant of the DIR, and the pressure of each reaction gas, the reaction rate equations of the WGSR and the DIR are determined; Based on the working voltage equation of the SOEC, the reaction rate equations of the WGSR and the DIR, the SOEC co-electrolysis model is constructed, and based on the SOEC co-electrolysis model, the dynamic optimization strategy of the input voltage, the inlet gas composition and the inlet gas temperature of the SOEC co-electrolysis is determined.

[0007] In a possible implementation, the method further includes determining the gas volume ratio of the WGSR and the gas volume ratio of the DIR, and determining the reversible voltage of the WGSR and the reversible voltage of the DIR, and determining the reversible voltage of the SOEC based on the gas volume ratio of the WGSR and the gas volume ratio of the DIR, and the reversible voltage of the WGSR and the reversible voltage of the DIR. The reversible voltage of the SOEC is determined based on the following formula:

[0008] wherein, V represents the reversible voltage of the SOEC, VWGSR represents the gas volume ratio of the WGSR, VDIR represents the gas volume ratio of the DIR, VWGSR represents the reversible voltage of the WGSR, and VDIR represents the reversible voltage of the DIR. In a possible implementation, the method further includes determining the equilibrium constant and the positive reaction constant of the WGSR and the DIR based on the stack temperature of the SOEC, and determining the positive reaction constant of the WGSR and the DIR based on the stack temperature of the SOEC and the ideal gas constant.

[0009] The equilibrium constant and the positive reaction constant of the WGSR and the DIR are determined based on the following formula:

[0010]

[0011]

[0012]

[0013]

[0014] wherein, kWGSR represents the positive reaction constant of the WGSR, KWGSR represents the equilibrium constant of the WGSR, kDIR represents the positive reaction constant of the DIR, and ​​​​represents the equilibrium constant of DIR, is an intermediate variable, represents the stack temperature of SOEC, is the ideal gas constant.

[0015] In a possible implementation, the reaction rate equations of WGSR and DIR are determined based on the equilibrium constant, the forward reaction constant of WGSR, and the equilibrium constant, the forward reaction constant of DIR, and the pressure of each reaction gas, and include: The reaction rate equations of WGSR and DIR are determined based on the following formula:

[0016]

[0017] wherein, represents the reaction rate of WGSR, represents the forward reaction constant of WGSR, represents the pressure of represents the pressure of represents the pressure of represents the pressure of represents the equilibrium constant of WGSR, represents the reaction rate of DIR, represents the forward reaction constant of DIR, represents the pressure of represents the equilibrium constant of DIR.

[0018] In a possible implementation, the SOEC co-electrolysis model is constructed based on the working voltage equation of SOEC and the reaction rate equations of WGSR and DIR, and includes: The SOEC co-electrolysis model is constructed by taking the working voltage equation of SOEC as an electrochemical sub-model and taking the reaction rate equations of WGSR and DIR as chemical reaction sub-models.

[0019] In a possible implementation, the dynamic optimization strategy of the input voltage, the inlet gas composition, and the inlet gas temperature of SOEC co-electrolysis is determined based on the SOEC co-electrolysis model, and includes: The dynamic optimization strategy of the input voltage, the inlet gas composition, and the inlet gas temperature of SOEC co-electrolysis is determined by solving the SOEC co-electrolysis model with the maximum temperature constraint and the maximum temperature gradient constraint of the SOEC stack as constraint conditions and with the SOEC co-electrolysis efficiency and the feed gas conversion rate as objective functions. ​​​​​

[0020] In one possible implementation, the dynamic optimization strategy includes: The input voltage is decreased at a first rate and increased at a second rate, and the input voltage is cyclically switched. The first rate is 1000 times the second rate. In maintaining and With the total mole fraction constant, it first increases at a third rate. The content then decreases at a fourth rate. The content, the fourth rate is 1000 times that of the third rate; The inlet gas temperature is increased at a fifth rate and decreased at a sixth rate, which is 1000 times the fifth rate.

[0021] On the other hand, the present invention also provides a dynamic optimization device for SOEC co-electrolysis, comprising: The first determining module is used to determine based on gas volume ratio and The gas volume percentage, and reversible voltage and The reversible voltage of SOEC is determined, and the working voltage equation of SOEC is determined based on the reversible voltage, activation overpotential, ohmic overpotential and concentration overpotential of SOEC. The second determining module is used to determine the equilibrium constants of WGSR and DIR based on the SOEC stack temperature, and to determine the forward reaction constants of WGSR and DIR based on the SOEC stack temperature and the ideal gas constant. The third determination module is used to determine the reaction rate equations for WGSR and DIR based on the equilibrium constants and forward reaction constants of WGSR and DIR, as well as the pressures of each reactant gas. The optimization module is used to construct a SOEC co-electrolysis model based on the SOEC working voltage equation and the reaction rate equations of WGSR and DIR. Based on the SOEC co-electrolysis model, the module determines the dynamic optimization strategy for the input voltage, inlet gas composition and inlet gas temperature of SOEC co-electrolysis.

[0022] Secondly, the present invention also provides a dynamic optimization device, including a memory and a processor, wherein, The memory is used to store programs; The processor, coupled to the memory, is used to execute the program stored in the memory to implement the steps in the dynamic optimization method for SOEC co-electrolysis described in any of the above implementations.

[0023] Thirdly, the present invention also provides a computer-readable storage medium for storing a computer-readable program or instructions, which, when executed by a processor, can implement the steps in the dynamic optimization method for SOEC co-electrolysis described in any of the above implementations.

[0024] The beneficial effects of this invention are as follows: The dynamic optimization method and apparatus for SOEC co-electrolysis of this invention, by determining the working voltage equation of SOEC and the reaction rate equations of WGSR and DIR, constructs an SOEC co-electrolysis model, thereby more accurately reflecting the characteristics of SOEC co-electrolysis and providing a basis for subsequent optimization processes. Then, by solving the SOEC co-electrolysis model, the dynamic optimization strategies for the input voltage, inlet gas composition, and inlet gas temperature of SOEC co-electrolysis are determined. Without changing the structure and materials of the SOEC co-electrolysis stack, the efficiency and stability of SOEC co-electrolysis are effectively improved. Attached Figure Description

[0025] Figure 1 A schematic flowchart of an embodiment of the dynamic optimization method for SOEC co-electrolysis provided by the present invention; Figure 2 A schematic flowchart of an embodiment of the dynamic optimization process for SOEC co-electrolysis provided by the present invention; Figure 3 A schematic diagram of an embodiment of the dynamic optimization device for SOEC co-electrolysis provided by the present invention; Figure 4 This is a schematic diagram of an embodiment of the dynamic optimization device provided by the present invention. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0027] In the description of the embodiments of the present invention, unless otherwise stated, "multiple" means two or more. "And / or" describes the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone.

[0028] The terms "first," "second," etc., used in the embodiments of this invention are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a technical feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature.

[0029] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0030] This invention provides a dynamic optimization method and apparatus for SOEC co-electrolysis, which will be described below.

[0031] Figure 1 This is a schematic flowchart of an embodiment of the dynamic optimization method for SOEC co-electrolysis provided by the present invention, as shown below. Figure 1 As shown, the dynamic optimization method for SOEC co-electrolysis includes: S101, based on gas volume ratio and The gas volume percentage, and reversible voltage and The reversible voltage of SOEC is determined, and the working voltage equation of SOEC is determined based on the reversible voltage, activation overpotential, ohmic overpotential and concentration overpotential of SOEC.

[0032] It should be noted that the dynamic optimization method for SOEC co-electrolysis provided by this invention can be applied to SOEC co-electrolysis scenarios, especially SOEC co-electrolysis scenarios under dynamic operating conditions.

[0033] When performing dynamic optimization of SOEC co-electrolysis, the dynamic optimization device (e.g., a portable computer or desktop computer) can first determine the optimal operating system based on the following parameters: volume ratio and The volume ratio, and reversible voltage and The reversible voltage of SOEC is determined by finding the reversible voltage of SOEC. Then, the working voltage equation of SOEC is determined based on the reversible voltage, activation overpotential, ohmic overpotential and concentration overpotential of SOEC, so as to more accurately reflect the characteristics of SOEC co-electrolysis.

[0034] S102. Determine the equilibrium constants of WGSR and DIR based on the SOEC stack temperature, and determine the forward reaction constants of WGSR and DIR based on the SOEC stack temperature and ideal gas constant.

[0035] It should be noted that the dynamic operating conditions of SOEC are mainly caused by the reversible water-gas shift reaction (WGSR) and the reversible direct internal reforming reaction (DIR). Therefore, the equilibrium constants of WGSR and DIR can be determined by the SOEC stack temperature, and the forward reaction constants of WGSR and DIR can be determined by the SOEC stack temperature and the ideal gas constant, thus more accurately reflecting the characteristics of SOEC co-electrolysis.

[0036] S103. Based on the equilibrium constants and forward reaction constants of WGSR and DIR, and the pressures of each reactant gas, determine the reaction rate equations for WGSR and DIR.

[0037] It should be noted that after determining the equilibrium constants and forward reaction constants of WGSR and DIR, the reaction rate equations of WGSR and DIR can be determined based on their equilibrium constants, forward reaction constants, and the pressures of each reactant gas. This equations reflect the reaction rates of WGSR and DIR in the SOEC co-electrolysis process, providing a basis for subsequent optimization.

[0038] S104. Based on the working voltage equation of SOEC and the reaction rate equations of WGSR and DIR, construct the SOEC co-electrolysis model, and determine the dynamic optimization strategy for the input voltage, inlet gas composition and inlet gas temperature of SOEC co-electrolysis based on the SOEC co-electrolysis model.

[0039] It should be noted that after determining the working voltage equation of SOEC and the reaction rate equations of WGSR and DIR, a SOEC co-electrolysis model can be constructed using the SOEC working voltage equation and the WGSR and DIR reaction rate equations. Then, by solving the SOEC co-electrolysis model, a dynamic optimization strategy for the input voltage, inlet gas composition, and inlet gas temperature of SOEC co-electrolysis can be determined. Without changing the SOEC co-electrolysis stack structure and materials, the efficiency and stability of SOEC co-electrolysis can be effectively improved.

[0040] In summary, the dynamic optimization method for SOEC co-electrolysis provided in this embodiment of the invention determines the working voltage equation of SOEC and the reaction rate equations of WGSR and DIR, and then constructs an SOEC co-electrolysis model, thereby more accurately reflecting the characteristics of SOEC co-electrolysis and providing a basis for subsequent optimization processes. Then, by solving the SOEC co-electrolysis model, the dynamic optimization strategies for the input voltage, inlet gas composition, and inlet gas temperature of SOEC co-electrolysis are determined. Without changing the structure and materials of the SOEC co-electrolysis stack, the efficiency and stability of SOEC co-electrolysis are effectively improved.

[0041] In some embodiments of the present invention, the basis gas volume ratio and The gas volume percentage, and reversible voltage and The reversible voltage of SOEC is determined by including: The reversible voltage of SOEC is determined based on the following formula:

[0042] in, This represents the reversible voltage of SOEC. express The gas volume percentage, express The gas volume percentage, express The reversible voltage, express The reversible voltage.

[0043] It should be noted that, considering the actual situation in SOEC co-electrolysis stacks... and The reversible voltages of electrolysis are not the same. This invention uses the weighted average of the reversible voltages of the electrolysis reactions of the two gases to calculate the total reversible voltage, which can more accurately reflect the characteristics of SOEC co-electrolysis.

[0044] In some embodiments of the present invention, the equilibrium constants and forward reaction constants of WGSR and DIR can be determined based on the following formulas:

[0045]

[0046]

[0047]

[0048]

[0049] in, This represents the forward reaction constant of WGSR. This represents the equilibrium constant of the WGSR. This represents the forward reaction constant of DIR. This represents the equilibrium constant of DIR. As an intermediate variable, This indicates the stack temperature of SOEC. is the ideal gas constant.

[0050] In some embodiments of the present invention, the reaction rate equations for WGSR and DIR can be determined based on the following formula:

[0051]

[0052] in, Indicates the reaction rate of WGSR, This represents the forward reaction constant of WGSR. express pressure, express pressure, express pressure, express pressure, This represents the equilibrium constant of the WGSR. Indicates the reaction rate of DIR. This represents the forward reaction constant of DIR. express pressure, This represents the equilibrium constant of DIR.

[0053] In some embodiments of the present invention, the construction of the SOEC co-electrolysis model based on the SOEC working voltage equation and the WGSR and DIR reaction rate equations includes: The SOEC co-electrolysis model is constructed by using the SOEC working voltage equation as an electrochemical sub-model and the WGSR and DIR reaction rate equations as chemical reaction sub-models.

[0054] It should be noted that the SOEC co-electrolysis model mainly comprises the construction of five sub-models: an electrochemical sub-model, a chemical reaction sub-model, an energy conservation sub-model, a mass conservation sub-model, and a degradation model. The energy conservation sub-model and the mass conservation sub-model can be constructed using general thermodynamic and mass conservation formulas, which will not be elaborated upon in this invention.

[0055] In some embodiments of the present invention, the dynamic optimization strategy for determining the input voltage, inlet gas composition, and inlet gas temperature of SOEC co-electrolysis based on the SOEC co-electrolysis model includes: Using the maximum temperature constraint and maximum temperature gradient constraint of the SOEC stack as constraints, and the SOEC co-electrolysis efficiency and feed gas conversion rate as objective functions, the SOEC co-electrolysis model is solved to determine the dynamic optimization strategy for the input voltage, inlet gas composition and inlet gas temperature of SOEC co-electrolysis.

[0056] It should be noted that when determining the dynamic optimization strategy for the input voltage, inlet gas composition, and inlet gas temperature of SOEC co-electrolysis based on the SOEC co-electrolysis model, the maximum temperature constraint and maximum temperature gradient constraint of the SOEC stack can be used as constraints. The SOEC co-electrolysis efficiency and feed gas conversion rate are used as objective functions to solve the SOEC co-electrolysis model, thereby determining the dynamic optimization strategy for the input voltage, inlet gas composition, and inlet gas temperature of SOEC co-electrolysis. This aims to effectively improve the efficiency and stability of SOEC co-electrolysis without changing the structure and materials of the SOEC co-electrolysis stack.

[0057] In some embodiments of the present invention, the dynamic optimization strategy includes: The input voltage is decreased at a first rate and increased at a second rate, and the input voltage is cyclically switched. The first rate is 1000 times the second rate. In maintaining and With the total mole fraction constant, it first increases at a third rate. The content then decreases at a fourth rate. The content, the fourth rate is 1000 times that of the third rate; The inlet gas temperature is increased at a fifth rate and decreased at a sixth rate, which is 1000 times the fifth rate.

[0058] It should be noted that, after simulation, the switching strategy of SOEC under dynamic operating conditions can be derived as follows: For the input voltage, a cyclic voltage switching strategy of rapid decrease (millisecond level) and slow increase (second level) is adopted; for the inlet gas composition, a... The content increases slowly (on the order of kiloseconds), then decreases rapidly (on the order of seconds), while maintaining a constant level. + A constant total mole fraction switching strategy is adopted; for inlet gas temperature, a slow temperature increase (kilosecond level) switching strategy is more suitable when the temperature rises, while a rapid temperature decrease (second level) switching strategy is adopted when the temperature falls.

[0059] CombinationFigure 2 The dynamic optimization process for SOEC co-electrolysis provided by this invention specifically includes the following steps: 1. SOEC co-electrolysis model construction.

[0060] Compared to pure electrolysis or The co-electrolysis process of SOEC involves more complex chemical and electrochemical reactions. Under co-electrolysis, a certain proportion of [unspecified substance] is introduced into the fuel electrode of the SOEC. , , A mixture is formed, with air introduced at the oxygen electrode. On the fuel electrode side, [something] will occur. and The respective electrolysis reactions, the electrolysis reaction at the fuel electrode is as follows:

[0061] Under the catalysis of metallic Ni, a series of catalytic chemical reactions may occur at the fuel electrode, mainly the reversible water-gas shift reaction (WGSR) and the reversible direct internal reforming reaction (DIR). As shown in the following equation:

[0062]

[0063] On the oxygen electrode side, oxygen ions from the fuel electrode move through the electrolyte to the oxygen electrode to generate oxygen gas, as shown in the following reaction:

[0064] The SOEC co-electrolysis model mainly involves the construction of five sub-models: an electrochemical sub-model, a chemical reaction sub-model, an energy conservation sub-model, a mass conservation sub-model, and a degradation model. The energy conservation and mass conservation sub-models can be constructed using general thermodynamic and mass conservation formulas, but additional parameters need to be considered. and The details of that part will not be elaborated upon here. This invention focuses on the construction of electrochemical sub-models and chemical reaction sub-models.

[0065] The main objective of the electrochemical sub-model is to solve the electrical characteristics of the SOEC stack, specifically the relationship between the stack voltage and current. The operating voltage of the SOEC can be obtained by subtracting the activation overpotential, ohmic overpotential, and concentration overpotential from the Nernst voltage, as shown in the following equation:

[0066] In the formula, For Nernst voltage, , and These are the activation overpotential, ohmic overpotential, and concentration overpotential, respectively. The Nernst voltage is also called the reversible voltage. The Nernst voltage under co-electrolysis is calculated as follows:

[0067] In the formula, This represents the percentage of the corresponding gas. and They are respectively and Each has its own reversible voltage.

[0068] The chemical reactant model primarily aims to solve for the reaction rate of a catalytic reaction. The solution is as follows:

[0069]

[0070]

[0071]

[0072]

[0073]

[0074]

[0075] In the formula, and The reaction rates of WGSR and DIR are respectively. and The forward reaction constants for WGSR and DIR, respectively. and The equilibrium constants for WGSR and DIR, respectively. Let be the pressure of gas i. Let be the ideal gas constant. This refers to the temperature of the fuel cell stack.

[0076] 2. Optimization strategy design for dynamic switching.

[0077] For typical SOEC materials, the constraints during operation are as follows:

[0078]

[0079] This represents the maximum temperature at the fuel cell node. This represents the maximum temperature gradient of the fuel cell stack. The above thermal safety constraints must be met during dynamic operation, while maximizing system efficiency and feed gas conversion rate. The main operating parameters of the SOEC co-electrolysis fuel cell stack include input voltage, inlet gas composition, and inlet gas temperature. Corresponding dynamic switching strategies are designed for each of these parameters.

[0080] Through simulation experiments using the SOEC co-electrolysis model, the present invention yields the following conclusions: Regarding the input voltage parameter, as the voltage decreases, the system efficiency exhibits a trend of first increasing and then decreasing. The initial increase in efficiency is due to the faster response speed of charge transfer compared to mass transfer. When the current density decreases with decreasing voltage, the gas composition remains constant for a short period, thus allowing for a sudden increase in efficiency. However, as the gas composition responds, the generated... / Rapidly decreasing the voltage will reduce efficiency. Finally, due to the feedback effect of the slow heat transfer process, the efficiency gradually stabilizes. In summary, rapidly decreasing the voltage (milliseconds) will cause efficiency to overshoot upwards, while slowly increasing the voltage (seconds) can avoid efficiency overshoot downwards. Therefore, for the input voltage, adopting a cyclic voltage switching strategy of rapid decrease (milliseconds) and slow increase (seconds) is beneficial to improving system efficiency.

[0081] Regarding the inlet gas composition, the inlet feed gas mainly consists of: and .exist Content step increase and After the content drops sharply (first step), efficiency, Conversion rate The conversion rate begins to increase 1 second after the first step, and the overall conversion rate of the feed gas improves after 100 seconds. However,... Content step drop and After a step increase in content (second step). Efficiency, Conversion rate The conversion rate improves within 100 seconds. Therefore, to improve efficiency and feed gas conversion rate, the first step should be slower, while the second step should be very fast. Thus, the optimal switching strategy should be... The content increases slowly (on the order of kiloseconds), then decreases rapidly (on the order of seconds), while maintaining a constant level. + The total mole fraction is constant.

[0082] Regarding the inlet gas temperature, when the temperature increases dramatically, the efficiency and total feed gas conversion rate decrease in the first second, and then increase over the next 2000 seconds. Conversely, when the temperature decreases dramatically, the parameters change in the opposite direction. When the temperature rises, a switching strategy of slow temperature increases (on the order of kiloseconds) is more suitable; while when the temperature decreases, a switching strategy of rapid temperature decreases (on the order of seconds) is more suitable.

[0083] In summary, the switching strategy for SOEC based on high-temperature co-electrolysis under dynamic operating conditions is as follows: For the input voltage, a cyclic voltage switching strategy of rapid decrease (millisecond level) and slow increase (second level) is adopted; for the inlet gas composition, a strategy of... The content increases slowly (on the order of kiloseconds), then decreases rapidly (on the order of seconds), while maintaining a constant level. + A constant total mole fraction switching strategy is adopted; for inlet gas temperature, a slow temperature increase (kilosecond level) switching strategy is more suitable when the temperature rises, while a rapid temperature decrease (second level) switching strategy is adopted when the temperature falls.

[0084] In terms of modeling, this invention considers the actual situation of SOEC co-electrolysis stacks. and The Nernst voltages of electrolysis are not the same. The total Nernst voltage is calculated by weighted average of the Nernst voltages of the electrolysis reactions of the two gases. The model calculated in this way can more accurately reflect the characteristics of SOEC co-electrolysis.

[0085] Most current research focuses on the steady-state performance analysis of SOEC co-electrolysis. This invention aims at improving system efficiency and proposes a dynamic switching strategy for the main operating parameters of SOEC co-electrolysis. Without changing the structure and materials of the SOEC co-electrolysis stack, this strategy effectively improves the efficiency and stability of SOEC co-electrolysis.

[0086] To better implement the dynamic optimization method for SOEC co-electrolysis in the embodiments of the present invention, based on the dynamic optimization method for SOEC co-electrolysis, the corresponding method is as follows: Figure 3 As shown, this embodiment of the invention also provides a dynamic optimization device for SOEC co-electrolysis. The dynamic optimization device 300 for SOEC co-electrolysis includes: The first determining module 301 is used for determining based on gas volume ratio and The gas volume percentage, and reversible voltage and The reversible voltage of SOEC is determined, and the working voltage equation of SOEC is determined based on the reversible voltage, activation overpotential, ohmic overpotential and concentration overpotential of SOEC. The second determining module 302 is used to determine the equilibrium constants of WGSR and DIR based on the SOEC stack temperature, and to determine the forward reaction constants of WGSR and DIR based on the SOEC stack temperature and the ideal gas constant. The third determining module 303 is used to determine the reaction rate equations of WGSR and DIR based on the equilibrium constant and forward reaction constant of WGSR and DIR, as well as the pressure of each reactant gas. The optimization module 304 is used to construct a SOEC co-electrolysis model based on the SOEC working voltage equation and the reaction rate equations of WGSR and DIR, and to determine the dynamic optimization strategy for the input voltage, inlet gas composition and inlet gas temperature of SOEC co-electrolysis based on the SOEC co-electrolysis model.

[0087] The SOEC co-electrolysis dynamic optimization device 300 provided in the above embodiments can realize the technical solutions described in the above SOEC co-electrolysis dynamic optimization method embodiments. The specific implementation principles of each module or unit can be found in the corresponding content in the above SOEC co-electrolysis dynamic optimization method embodiments, which will not be repeated here.

[0088] like Figure 4 As shown, the present invention also provides a dynamic optimization device 400. The dynamic optimization device 400 includes a processor 401, a memory 402, and a display 403. Figure 4 Only some components of the dynamic optimization device 400 are shown; however, it should be understood that it is not required to implement all of the components shown, and more or fewer components may be implemented instead.

[0089] In some embodiments, processor 401 may be a central processing unit (CPU), microprocessor, or other data processing chip, used to run program code stored in memory 402 or process data, such as the dynamic optimization method for SOEC co-electrolysis in this invention.

[0090] In some embodiments, processor 401 may be a single server or a group of servers. The server group may be centralized or distributed. In some embodiments, processor 401 may be local or remote. In some embodiments, processor 401 may be implemented on a cloud platform. In one embodiment, the cloud platform may include a private cloud, public cloud, hybrid cloud, community cloud, distributed cloud, internal cloud, multi-cloud, etc., or any combination thereof.

[0091] In some embodiments, memory 402 may be an internal storage unit of dynamic optimization device 400, such as a hard disk or memory of dynamic optimization device 400. In other embodiments, memory 402 may also be an external storage device of dynamic optimization device 400, such as a pluggable hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc. equipped on dynamic optimization device 400.

[0092] Furthermore, the memory 402 may include both internal storage units of the dynamic optimization device 400 and external storage devices. The memory 402 is used to store application software and various types of data installed on the dynamic optimization device 400.

[0093] In some embodiments, display 403 may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, or an organic light-emitting diode (OLED) touchscreen, etc. Display 403 is used to display information from the dynamic optimization device 400 and to display a visual user interface. Components 401-403 of the dynamic optimization device 400 communicate with each other via a system bus.

[0094] In one embodiment, when processor 401 executes the dynamic optimization program for SOEC co-electrolysis in memory 402, the following steps can be implemented: based on gas volume ratio and The gas volume percentage, and reversible voltage and The reversible voltage of SOEC is determined, and the working voltage equation of SOEC is determined based on the reversible voltage, activation overpotential, ohmic overpotential and concentration overpotential of SOEC. The equilibrium constants of WGSR and DIR were determined based on the SOEC stack temperature, and the forward reaction constants of WGSR and DIR were determined based on the SOEC stack temperature and the ideal gas constant. Based on the equilibrium constant and forward reaction constant of WGSR and DIR, and the pressure of each reactant gas, the reaction rate equations for WGSR and DIR are determined. Based on the working voltage equation of SOEC and the reaction rate equations of WGSR and DIR, a SOEC co-electrolysis model is constructed. Based on the SOEC co-electrolysis model, dynamic optimization strategies for the input voltage, inlet gas composition and inlet gas temperature of SOEC co-electrolysis are determined.

[0095] It should be understood that when the processor 401 executes the dynamic optimization program for SOEC co-electrolysis in the memory 402, in addition to the functions mentioned above, it can also perform other functions, as detailed in the description of the corresponding method embodiments above.

[0096] Furthermore, this embodiment of the invention does not specifically limit the type of the dynamically optimized device 400 mentioned. The dynamically optimized device 400 can be a portable electronic device such as a mobile phone, tablet computer, personal digital assistant (PDA), wearable device, or laptop computer. Exemplary embodiments of portable electronic devices include, but are not limited to, portable electronic devices running iOS, Android, Microsoft, or other operating systems. The aforementioned portable electronic devices can also be other portable electronic devices, such as laptop computers with touch-sensitive surfaces (e.g., touch panels). It should also be understood that in some other embodiments of the invention, the dynamically optimized device 400 may not be a portable electronic device, but rather a desktop computer with a touch-sensitive surface (e.g., a touch panel).

[0097] Accordingly, this application also provides a computer-readable storage medium for storing a computer-readable program or instruction. When the program or instruction is executed by a processor, it can implement the steps or functions of the dynamic optimization method for SOEC co-electrolysis provided in the above-described method embodiments.

[0098] Those skilled in the art will understand that all or part of the processes of the methods described in the above embodiments can be implemented by a computer program instructing related hardware (such as a processor, controller, etc.), and the computer program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a disk, optical disk, read-only memory, or random access memory, etc.

[0099] The above provides a detailed description of the dynamic optimization method and apparatus for SOEC co-electrolysis provided by the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A dynamic optimization method for SOEC co-electrolysis, characterized in that, include: based on gas volume ratio and The gas volume percentage, and reversible voltage and The reversible voltage of SOEC is determined, and the working voltage equation of SOEC is determined based on the reversible voltage, activation overpotential, ohmic overpotential and concentration overpotential of SOEC. The equilibrium constants of WGSR and DIR were determined based on the SOEC stack temperature, and the forward reaction constants of WGSR and DIR were determined based on the SOEC stack temperature and the ideal gas constant. Based on the equilibrium constant and forward reaction constant of WGSR and DIR, and the pressure of each reactant gas, the reaction rate equations for WGSR and DIR are determined. Based on the working voltage equation of SOEC and the reaction rate equations of WGSR and DIR, a SOEC co-electrolysis model is constructed. Based on the SOEC co-electrolysis model, dynamic optimization strategies for the input voltage, inlet gas composition and inlet gas temperature of SOEC co-electrolysis are determined.

2. The dynamic optimization method for SOEC co-electrolysis according to claim 1, characterized in that, The basis gas volume ratio and The gas volume percentage, and reversible voltage and The reversible voltage of SOEC is determined by including: The reversible voltage of SOEC is determined based on the following formula: in, This represents the reversible voltage of SOEC. express The gas volume percentage, express The gas volume percentage, express The reversible voltage, express The reversible voltage.

3. The dynamic optimization method for SOEC co-electrolysis according to claim 1, characterized in that, The determination of the equilibrium constants of WGSR and DIR based on the SOEC stack temperature, and the determination of the forward reaction constants of WGSR and DIR based on the SOEC stack temperature and the ideal gas constant, includes: The equilibrium constants and forward reaction constants of WGSR and DIR are determined based on the following formulas: in, This represents the forward reaction constant of WGSR. This represents the equilibrium constant of the WGSR. This represents the forward reaction constant of DIR. This represents the equilibrium constant of DIR. As an intermediate variable, This indicates the stack temperature of SOEC. is the ideal gas constant.

4. The dynamic optimization method for SOEC co-electrolysis according to claim 1, characterized in that, The reaction rate equations for WGSR and DIR are determined based on the equilibrium constants and forward reaction constants of WGSR and DIR, and the pressures of each reactant gas, including: The reaction rate equations for WGSR and DIR are determined based on the following formula: in, Indicates the reaction rate of WGSR, This represents the forward reaction constant of WGSR. express pressure, express pressure, express pressure, express pressure, This represents the equilibrium constant of the WGSR. Indicates the reaction rate of DIR. This represents the forward reaction constant of DIR. express pressure, This represents the equilibrium constant of DIR.

5. The dynamic optimization method for SOEC co-electrolysis according to claim 1, characterized in that, The SOEC co-electrolysis model, constructed based on the SOEC working voltage equation and the WGSR and DIR reaction rate equations, includes: The SOEC co-electrolysis model is constructed by using the SOEC working voltage equation as an electrochemical sub-model and the WGSR and DIR reaction rate equations as chemical reaction sub-models.

6. The dynamic optimization method for SOEC co-electrolysis according to claim 1, characterized in that, The dynamic optimization strategy for determining the input voltage, inlet gas composition, and inlet gas temperature of SOEC co-electrolysis based on the SOEC co-electrolysis model includes: Using the maximum temperature constraint and maximum temperature gradient constraint of the SOEC stack as constraints, and the SOEC co-electrolysis efficiency and feed gas conversion rate as objective functions, the SOEC co-electrolysis model is solved to determine the dynamic optimization strategy for the input voltage, inlet gas composition and inlet gas temperature of SOEC co-electrolysis.

7. The dynamic optimization method for SOEC co-electrolysis according to claim 6, characterized in that, The dynamic optimization strategy includes: The input voltage is decreased at a first rate and increased at a second rate, and the input voltage is cyclically switched. The first rate is 1000 times the second rate. In maintaining and With the total mole fraction constant, it first increases at a third rate. The content then decreases at a fourth rate. The content, the fourth rate is 1000 times that of the third rate; The inlet gas temperature is increased at a fifth rate and decreased at a sixth rate, which is 1000 times the fifth rate.

8. A dynamic optimization device for SOEC co-electrolysis, characterized in that, include: The first determining module is used to determine based on gas volume ratio and The gas volume percentage, and reversible voltage and The reversible voltage of SOEC is determined, and the working voltage equation of SOEC is determined based on the reversible voltage, activation overpotential, ohmic overpotential and concentration overpotential of SOEC. The second determining module is used to determine the equilibrium constants of WGSR and DIR based on the SOEC stack temperature, and to determine the forward reaction constants of WGSR and DIR based on the SOEC stack temperature and the ideal gas constant. The third determination module is used to determine the reaction rate equations for WGSR and DIR based on the equilibrium constants and forward reaction constants of WGSR and DIR, as well as the pressures of each reactant gas. The optimization module is used to construct a SOEC co-electrolysis model based on the SOEC working voltage equation and the reaction rate equations of WGSR and DIR. Based on the SOEC co-electrolysis model, the module determines the dynamic optimization strategy for the input voltage, inlet gas composition and inlet gas temperature of SOEC co-electrolysis.

9. A dynamic optimization device, characterized in that, Including memory and processor, among which, The memory is used to store programs; The processor, coupled to the memory, is used to execute the program stored in the memory to implement the steps in the dynamic optimization method for SOEC co-electrolysis according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, Used to store computer-readable programs or instructions, which, when executed by a processor, can implement the steps in the dynamic optimization method for SOEC co-electrolysis as described in any one of claims 1 to 7.

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