Method for evaluating selection of hydrogen production system with hybrid electrolyzer

Abstract

The application discloses a kind of mixed electrolytic cell hydrogen production system selection evaluation method, consider the technical and economic characteristics of proton exchange membrane electrolytic cell and alkaline electrolytic cell, select the 8 indexes of two types of electrolytic cell as the index layer of evaluation model and participate in evaluation;Build multilayer selection evaluation model, the evaluation model includes target layer, index layer and scheme layer;8 indexes of index layer are compared, construct evaluation matrix, and the consistency of evaluation matrix is tested;Based on the weight matrix of evaluation matrix, the weight vector of 8 indexes and the weight vector of n schemes are calculated according to the weight matrix;The total score of each scheme is calculated, and the scheme with the maximum total score is the optimal configuration scheme of mixed electrolytic cell.The above-mentioned method extracts multiple key indicators of two types of electrolytic cell, establishes a multilayer selection evaluation model, and finally selects the optimal configuration scheme of mixed electrolytic cell with high cost performance.

Description

Technical Field

[0001] This invention relates to the field of electrolyzer technology, and in particular to a method for selecting and evaluating a hybrid electrolyzer hydrogen production system. Background Technology

[0002] Photovoltaic water electrolysis for hydrogen production is beneficial for both the consumption of renewable energy and the effective solution to the problem of green hydrogen production. The electrolyzer, as a key component of the photovoltaic water electrolysis hydrogen production system, plays a crucial role in the system's energy utilization and hydrogen production efficiency. Currently, alkaline electrolyzers (AELs) are relatively inexpensive (3000 RMB / kW) and have been widely commercialized. However, AELs have a long cold start time of 60-120 minutes under rated load and a hot start time of 60-300 seconds, resulting in a high hydrogen production rate of only 2.09 Nm³. 3 / h·m 2 Furthermore, the instability of fluctuating power supply output will cause a decrease in AEL electrolysis efficiency, hydrogen production, and damage to AEL equipment. To improve the compatibility of AELs with fluctuating power supplies, researchers have used energy storage systems to assist photovoltaic systems in hydrogen production. While this method improves the operational lifespan of AELs to some extent, it significantly increases hydrogen production costs, and the inherent limitations of AEL performance are not addressed. In contrast, proton exchange membrane electrolyzers (PEMELs) have a hot start-up time of less than 10 seconds, higher hydrogen production efficiency, and a hydrogen production capacity of up to 12.54 Nm³. 3 / h·m 2 Furthermore, it has good compatibility with fluctuating power supplies. Currently, PEMEL applications have entered the engineering demonstration stage. However, PEMEL equipment costs are high (9,000 yuan / kW), making large-scale application impossible.

[0003] Currently, there is very little research on the selection and configuration technology of hybrid electrolyzers (AEL and PEMEL). Most existing technologies only consider combining the energy efficiency and economic characteristics of the two types of electrolyzers and use online optimization algorithms for optimal configuration. Therefore, how to solve the problem of selection and evaluation between the wide-range, high-efficiency, and fast-response PEMEL and the low-cost, low-pressure, and high single-stack power AEL, and form a high-performance and cost-effective hybrid electrolyzer hydrogen production system, is an urgent problem to be solved in the application of hybrid electrolyzers. Summary of the Invention

[0004] The purpose of this invention is to provide a method for selecting and evaluating a hybrid electrolyzer hydrogen production system. This method extracts multiple key indicators of two types of electrolyzers, establishes a multi-layer selection and evaluation model, and finally selects the optimal configuration scheme of the hybrid electrolyzer with high cost performance. The evaluation results are more accurate and objective, and meet the needs of actual operation.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A method for selecting and evaluating a hybrid electrolyzer hydrogen production system, the method comprising:

[0007] Step 1: Based on the hydrogen production characteristics, dynamic response characteristics, energy consumption and economic characteristics of proton exchange membrane electrolyzers and alkaline electrolyzers, eight indicators of the two types of electrolyzers are selected as the indicator layer of the evaluation model to participate in the evaluation.

[0008] The eight indicators include: rated current density, denoted as I1; hydrogen production, denoted as I2; hot start time under rated load, denoted as I3; load range, denoted as I4; dynamic response time, denoted as I5; electrolyzer energy consumption, denoted as I6; electrolyzer life, denoted as I7; and equipment cost, denoted as I8.

[0009] Step 2: Construct a multi-layer selection and evaluation model, which includes an objective layer, an indicator layer, and a scheme layer; wherein, the objective layer is the optimal configuration of the hybrid electrolyzer; the indicator layer consists of 8 selected indicators; and the scheme layer includes n schemes.

[0010] Step 3: Compare the eight indicators in the indicator layer, construct an evaluation matrix, and verify the consistency of the evaluation matrix;

[0011] Step 4: Construct a weight matrix based on the evaluation matrix constructed in Step 3, and calculate the weight vectors of the 8 indicators and the weight vectors of the n schemes according to the weight matrix.

[0012] Step 5: Calculate the total score of each scheme based on the weight vectors of the 8 indicators and the weight vectors of the n schemes. The scheme with the highest total score is the optimal configuration scheme for the hybrid electrolyzer.

[0013] As can be seen from the technical solution provided by the present invention, the above method extracts multiple key indicators of two types of electrolyzers, establishes a multi-layer selection and evaluation model, and finally selects the optimal configuration scheme of the high-performance hybrid electrolyzer. The evaluation results are more accurate and objective, and meet the needs of actual operation. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the method for selecting and evaluating a hybrid electrolyzer hydrogen production system provided in an embodiment of the present invention;

[0016] Figure 2 This is a schematic diagram of the multi-layer selection evaluation model described in an embodiment of the present invention. Detailed Implementation

[0017] 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 some embodiments of the present invention, and not all embodiments, and do not constitute a limitation of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0018] like Figure 1 The diagram shows a flowchart of a method for selecting and evaluating a hybrid electrolyzer hydrogen production system according to an embodiment of the present invention. The method includes:

[0019] Step 1: Based on the hydrogen production characteristics, dynamic response characteristics, energy consumption and economic characteristics of proton exchange membrane electrolyzers and alkaline electrolyzers, eight indicators of the two types of electrolyzers are selected as the indicator layer of the evaluation model to participate in the evaluation.

[0020] The eight indicators are as follows: Indicator 1: Rated current density, denoted as I1; Indicator 2: Hydrogen production, denoted as I2; Indicator 3: Hot start time under rated load, denoted as I3; Indicator 4: Load range, denoted as I4; Indicator 5: Dynamic response time, denoted as I5; Indicator 6: Electrolyzer energy consumption, denoted as I6; Indicator 7: Electrolyzer lifespan, denoted as I7; Indicator 8: Equipment cost, denoted as I8.

[0021] Step 2: Construct a multi-layered selection and evaluation model, which includes an objective layer, an indicator layer, and a solution layer;

[0022] The target layer is the optimal configuration of the hybrid electrolyzer; the index layer consists of 8 selected indexes; and the scheme layer includes n schemes.

[0023] like Figure 2 The diagram shown is a schematic diagram of the multi-layer selection evaluation model according to an embodiment of the present invention. Figure 2The target layer includes the optimal configuration of the hybrid electrolyzer; the index layer includes 8 selected indexes, namely I1, I2, I3, I4, I5, I6, I7, and I8; and the scheme layer includes n schemes, denoted as F1, F2, ..., Fn.

[0024] Step 3: Compare the eight indicators in the indicator layer, construct an evaluation matrix, and verify the consistency of the evaluation matrix;

[0025] In this step, eight indicators from the indicator layer are compared to construct an evaluation matrix A = (a ij ) 8×8 ,i,j=1,2,3…8, where a ij This indicates the relative importance of the i-th and j-th indicators in the intermediate layer to the target layer, and is assigned a value through comparison by the database.

[0026] In specific implementation, the database has access to a ij The comparison and assignment process is as follows:

[0027] Define h Ii ,i=1,2,3…8 represents the standard ratio of each index, and the value is the quotient of the index values ​​of the proton exchange membrane electrolyzer and the alkaline electrolyzer, and h Ii ≥1; Define h ij h is the standard ratio of the i-th indicator Ii Divided by the standard ratio h of the j-th indicator Ij , i.e. h ij =h Ii / h Ij If h ij ≥1, a ij The values ​​for a are referenced in Table 1. ji =1 / a ij If h ij If <1, then calculate h. ji =1 / h ij a ji The values ​​for a are referenced in Table 1. ij =1 / a ji Finally, the evaluation matrix A = (a ij ) 8×8 ;

[0028] Table 1. Assignment criteria for evaluation matrix A in a certain database.

[0029]

[0030] There are n alternatives in the solution layer. For the i-th indicator in the indicator layer, construct the evaluation matrix B among the alternatives. i =(b ipq ) n×np, q = 1, 2, 3…n, i = 1, 2, 3…8, where b ipq This indicates the superiority of the p-th solution relative to the q-th solution for the i-th metric, which is assigned by comparison in the database;

[0031] In the specific implementation, the database accesses b ipq The comparison and assignment process is as follows:

[0032] Define the capacity of the proton exchange membrane electrolyzer in the p-th scheme as P. pem_p p = 1, 2…n, the capacity of the alkaline electrolytic cell is P ael_p p = 1, 2, ..., n; for the i-th indicator in the indicator layer, define k ip Let i = 1, 2, 3… 8 be the standard ratios of scheme p, with values ​​as follows: If the standard ratio h of the i-th index… Ii Let i = 1, 2, 3… 8 be the index values ​​of a proton exchange membrane electrolyzer divided by the index values ​​of an alkaline electrolyzer, then k ip =h Ii ·P pem_p / P ael_p If the standard of the i-th indicator is greater than h Ii Let i = 1, 2, 3… 8 be the index values ​​of an alkaline electrolyzer divided by the index values ​​of a proton exchange membrane electrolyzer, then k ip =h Ii ·P ael_p / P pem_p ;

[0033] Define v ipq For the i-th indicator in the indicator layer, the standard ratio k of the p-th scheme is... ip Divided by the standard ratio k of the qth indicator iq That is, v ipq =k ip / k iq If v ipq ≥1, b ipq The values ​​for b are referenced in Table 2. iqp =1 / b ipq If v ipq If <1, then calculate v. iqp =1 / v ipq b iqp The values ​​for b are referenced in Table 2. ipq =1 / b iqp ;

[0034] Table 2 shows the evaluation matrix B for a certain database. i Assignment Standard Table

[0035]

[0036] The final evaluation matrix is ​​represented as: Aχ B χi χ = 1, 2, 3…N, i = 1, 2, 3…8; χ represents the number of databases, N represents the total number of databases; A χ B represents the evaluation matrix among the indicators obtained from assigning values ​​to the x-th database; χi Let χ represent the χ-th database, and for the ith index in the index layer, assign the evaluation matrix between the various schemes.

[0037] Then, the evaluation matrix A is calculated sequentially. χ B χi The random consistency ratio CR, when CR < 0.1, determines the evaluation matrix A. χ B χi Evaluation matrices that meet consistency requirements are selected, and those that do not meet consistency requirements are discarded.

[0038] The formula for calculating the random consistency ratio CR is shown in equation (1):

[0039]

[0040] In equation (1), CI is an indicator that measures the degree of inconsistency in the evaluation matrix; λ max The eigenvalue is the eigenvalue with the largest absolute value in the matrix being evaluated; w is the number of indicators, here w = 8; RI is the average random consistency index, which is obtained by repeatedly calculating based on the matrix order. For example, Table 3 below shows the RI values ​​obtained after repeatedly calculating 1000 times for matrices of order 1 to 9:

[0041] Table 3 Average Random Consistency Index

[0042]

[0043] In this example, since w = 8, we know from Table 2 that RI = 1.41.

[0044] Step 4: Construct a weight matrix based on the evaluation matrix constructed in Step 3, and calculate the weight vectors of the 8 indicators and the weight vectors of the n schemes according to the weight matrix.

[0045] In this step, the evaluation matrix A is calculated. χ λ, the eigenvalues ​​of χ = 1, 2, 3…N max (A χ And the eigenvectors corresponding to the eigenvalues, after standardizing the eigenvectors, we obtain That is, evaluation matrix A χ The weight vector, where i = 1, 2, 3… 8 represents the weight value assigned to the i-th index by the χ-th database for the optimal configuration objective of the hybrid electrolyzer; similarly, the evaluation matrix B is obtained. χi The weight vector α χi=[α χ1i ,α χ2i ,α χ3i …α χni ] T , where α χpi p = 1, 2, 3…n represents the weight value assigned to the p-th scheme by the χ-th database for the i-th index;

[0046] Construct weight matrices C and D i As shown in equation (2):

[0047]

[0048] Further weight matrix Standardization processing is performed, and the standardized calculation is shown in equation (3):

[0049]

[0050] In equation (3), These are all elements in the i-th column of the weight matrix C; for The minimum value among the element values; for The maximum value among the element values; r χi for The standardized values ​​can then be used to obtain the standardized matrix of the weight matrix C.

[0051] weight matrix For i = 1, 2, 3…8, standardization is performed, and the standardization calculation is shown in equation (4):

[0052]

[0053] In equation (4), α pi The weight matrix D i All elements in the p-th column; min(α) pi ) is α pi The minimum value among the element values; max(α) pi ) is α pi The maximum value among the element values; yχ pi For α χpi The standardized values ​​then yield the weight matrix D. i Standardized matrix

[0054] Then, based on the normalization matrix R * =(r χi ) N×8 and The specific process for calculating the weight vectors of the 8 indicators and the weight vectors of the n options is as follows:

[0055] Define f χi The proportion of the χ-th database assigned to the ith index is determined by the standardization matrix. Calculate f χi The calculation formula is shown in equation (5):

[0056]

[0057] According to f χi The weight vector of the eight indicators is calculated using the formula shown in equation (6):

[0058]

[0059] In equation (6), N is the total number of databases; e i Let be the weight of the i-th indicator, and the final weight vector for all indicators is E = [e1, e2, e3…e8]. T ;

[0060] Define z χpi To determine the proportion of the p-th scheme assigned to the χ-th database for index i, based on the standardization matrix... Calculate z χpi The calculation formula is shown in equation (7):

[0061]

[0062] According to z χpi The weight vectors of the n schemes are calculated using the formula shown in equation (8):

[0063]

[0064] In equation (8), N is the total number of databases; g pi For index i, the weight of the p-th scheme, p = 1, 2, ..., n, ultimately forms the weight vector of each scheme as G. i =[g 1i ,g 2i ,g 3i …g ni ] T .

[0065] Step 5: Calculate the total score of each scheme based on the weight vectors of the 8 indicators and the weight vectors of the n schemes. The scheme with the highest total score is the optimal configuration scheme for the hybrid electrolyzer.

[0066] In this step, the weight vector of each indicator is E = [e1, e2, e3…e8]. T and the weight vector G of each scheme i =[g 1i ,g 2i,g 3i …g ni ] T Calculate the total score J for each option. p p = 1, 2…n, the calculation formula is shown in equation (9):

[0067] J p =e1×g p1 +e2×g p2 …e i ×g pi …e8×g n8 (9)

[0068] max(J p The corresponding scheme is the optimal configuration scheme for the hybrid electrolyzer.

[0069] It is worth noting that the contents not described in detail in the embodiments of the present invention belong to the prior art known to those skilled in the art.

[0070] In summary, the method described in this embodiment of the invention can solve the problem of selecting and configuring a hybrid electrolyzer consisting of proton exchange membrane electrolyzers and alkaline electrolyzers. It fully considers the advantages and disadvantages of the two types of electrolyzers in terms of hydrogen production characteristics, dynamic response characteristics, energy consumption, and economic characteristics. It extracts eight key indicators of the two types of electrolyzers, establishes a multi-layer selection and evaluation model, and selects a high-performance hybrid electrolyzer hydrogen production system. This greatly improves the photovoltaic utilization rate and hydrogen production of the photovoltaic water electrolysis hydrogen production system, and promotes the development of the hydrogen production industry.

[0071] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims. The information disclosed in the background section is intended only to enhance the understanding of the overall background technology of the present invention and should not be construed as an admission or implication in any way that such information constitutes prior art known to those skilled in the art.

Claims

1. A method for selecting and evaluating a hybrid electrolyzer hydrogen production system, characterized in that, The method includes: Step 1: Based on the hydrogen production characteristics, dynamic response characteristics, energy consumption and economic characteristics of proton exchange membrane electrolyzers and alkaline electrolyzers, eight indicators of the two types of electrolyzers are selected as the indicator layer of the evaluation model to participate in the evaluation. The eight indicators include: rated current density, denoted as I1; hydrogen production, denoted as I2; hot start time under rated load, denoted as I3; load range, denoted as I4; dynamic response time, denoted as I5; electrolyzer energy consumption, denoted as I6; electrolyzer life, denoted as I7; and equipment cost, denoted as I8. Step 2: Construct a multi-layered selection and evaluation model, which includes an objective layer, an indicator layer, and a scheme layer. The objective layer represents the optimal configuration of the hybrid electrolyzer; the indicator layer comprises eight selected indicators; and the scheme layer includes... One option; Step 3: Compare the eight indicators in the indicator layer, construct an evaluation matrix, and verify the consistency of the evaluation matrix; Step 4: Construct a weight matrix based on the evaluation matrix built in Step 3, and calculate the weight vectors of the eight indicators according to the weight matrix. The weight vector of each scheme; The process of step 4 is as follows: Calculate the evaluation matrix eigenvalues And the eigenvectors corresponding to the eigenvalues, after standardizing the eigenvectors, we obtain That is, the evaluation matrix The weight vector, where This represents the optimal configuration objective for hybrid electrolyzers, the first... Each database assigns a weight value to the i-th indicator; similarly, the evaluation matrix is ​​obtained. weight vector ,in This means that for the i-th indicator, the th The database assigns the first The weight values ​​of the proposed solutions; Construct the weight matrix As shown in equation (2): （2） Further weight matrix Standardization processing is performed, and the standardized calculation is shown in equation (3): （3） In equation (3), Weight matrix The Middle All elements of the column; for The minimum value among the element values; for The maximum value among the element values; for The standardized values ​​then yield the weight matrix. Standardized matrix ; weight matrix Standardization processing is performed, and the standardized calculation is shown in equation (4): （4） In equation (4), Weight matrix The Middle All elements of the column; for The minimum value among the element values; for The maximum value among the element values; for The standardized values ​​then yield the weight matrix. Standardized matrix ; Then based on the normalization matrix and Calculate the weight vector of the eight indicators and The weight vectors of each scheme are defined as follows: definition For the first The database for the first The weight of each indicator's value is determined by the standardized matrix. calculate The calculation formula is shown in equation (5): （5） according to The weight vector of the eight indicators is calculated using the formula shown in equation (6): （6） In equation (6), Total number of databases; For the first The weights of each indicator are determined, ultimately forming a weight vector for each indicator. ; definition To target indicators , No. The database for the first The proportion of the assigned value is determined by the standardization matrix. calculate The calculation formula is shown in equation (7): （7） according to calculate The weight vector of each scheme is calculated using the formula shown in equation (8): （8） In equation (8), Total number of databases; To target indicators , No. The weights of each option, The final weight vector for each scheme is as follows: ; Step 5: Then, based on the weight vectors of the eight indicators... The total score of each scheme is calculated by weighting the weight vectors of each scheme, and the scheme with the largest total score is the optimal configuration scheme of the hybrid electrolyzer.

2. The method for selecting and evaluating a hybrid electrolyzer hydrogen production system according to claim 1, characterized in that, The process of step 3 is as follows: The eight indicators in the indicator layer are compared to construct an evaluation matrix. ,in Indicates the middle layer The first indicator and the first The importance of each indicator relative to the target layer is compared and assigned values ​​by the database. The solution layer has a total of One option is available for selection, for the first indicator layer. Using several indicators, construct an evaluation matrix among the various schemes. ,in Indicates for the first The first indicator, the The first scheme is relative to the second. The superiority of each solution is determined by comparison and assignment in the database; The final evaluation matrix is ​​represented as follows: ; Represents a database. Indicates the total number of databases; Indicates the first An evaluation matrix among the indicators obtained from assigning values ​​to each database; Indicates the first The database, for the first indicator layer Each indicator is assigned a value to the evaluation matrix between the various solutions; Then calculate the evaluation matrix sequentially. random consistency ratio ,when At that time, the evaluation matrix is ​​determined. Evaluation matrices that meet consistency requirements are selected, and those that do not meet consistency requirements are discarded. Among them, the random consistency ratio The calculation formula is shown in equation (1): （1） In equation (1), An indicator for measuring the degree of inconsistency in the evaluation matrix; The eigenvalue that evaluates the matrix with the largest absolute value; Here, the number of indicators is... ; It is the average random consistency index, which is obtained by repeatedly calculating based on the matrix order. ,but .

3. The method for selecting and evaluating a hybrid electrolyzer hydrogen production system according to claim 2, characterized in that, Database The comparison and assignment process is as follows: definition The standard ratio of each indicator is taken as the quotient of the indicator values ​​for the proton exchange membrane electrolyzer and the alkaline electrolyzer. ;definition For the first Standard ratio of each indicator Divided by the Standard ratio of each indicator ,Right now ;if , The values ​​are referenced in Table 1. ;if Then calculate , The values ​​are referenced in Table 1. Finally, the evaluation matrix after assignment is obtained. ; Table 1. Standard for assigning values ​​to evaluation matrix A in a certain database. ； Database The comparison and assignment process is as follows: Definition of the first In each scheme, the capacity of the proton exchange membrane electrolyzer is: The capacity of the alkaline electrolytic cell is For the first indicator layer One indicator, defined for The standard ratio of the scheme takes the following values: if the first... Standard ratio of each indicator The ratio of the proton exchange membrane electrolyzer index value to the alkaline electrolyzer index value is: If the first Standard ratio of each indicator The index value of an alkaline electrolyzer is divided by the index value of a proton exchange membrane electrolyzer. ; definition For the first indicator layer The first indicator, the p The standard ratio of each scheme Divided by the q Standard ratio of each indicator ,Right now ,if , The values ​​are referenced in Table 2. ;if Then calculate , The values ​​are referenced in Table 2. ; Table 2 Evaluation matrix B for a certain database i Assignment Standard Table 。 4. The method for selecting and evaluating a hybrid electrolyzer hydrogen production system according to claim 1, characterized in that, In step 5, based on the weight vector of each indicator... and the weight vector of each scheme Calculate the total score for each option. The calculation formula is shown in equation (9): （9） The corresponding scheme is the optimal configuration scheme for the hybrid electrolyzer.

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