Method of assembling a fuel cell stack

Abstract

Provided is a method of combining fuel cell stacks, which makes it possible to determine an optimal combination of fuel cell stacks. A fuel cell system 1 includes a plurality of fuel cell modules 11 each having a plurality of fuel cell stacks 12 connected in series and connected in parallel to each other. An inspection device 2 includes an output acquisition unit 21 that acquires an output value for each of the plurality of fuel cell stacks 12, a degradation estimation unit 22 that estimates a future degradation degree for each of the plurality of fuel cell stacks 12, and a future output estimation unit 23 that estimates a future output value, which is an output value after a predetermined period, for each of the plurality of fuel cell stacks 12 based on the future degradation degree estimated by the degradation estimation unit 22. A method of combining the fuel cell stacks 12 determines a combination of the plurality of fuel cell stacks 12 based on a difference between the output values of the plurality of fuel cell stacks 12 and a difference between the future output values of the plurality of fuel cell stacks 12.

Description

Technical Field

[0001] This invention relates to a method for assembling a fuel cell stack. Background Technology

[0002] Previously, a technique was proposed that, when replacing a battery, measures the current degradation state of multiple battery modules constituting the used battery, and based on the measurement results, combines battery modules that meet the user's battery replacement requirements (see, for example, Patent Document 1). According to this technique, by measuring the current degradation state, an optimal combination of battery modules can be achieved.

[0003] [Existing Technical Documents]

[0004] [Patent Literature]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2010-172122 Summary of the Invention

[0006] [The problem the invention aims to solve]

[0007] However, the technology in Patent Document 1 does not take into account future degradation due to subsequent use of the battery module. Therefore, there is room for improvement in order to achieve a better combination of battery modules.

[0008] Furthermore, in systems where multiple fuel cell modules are connected in parallel, without voltage control mechanisms such as an FCVCU (Fuel Cell Voltage Control Unit), the voltage of each fuel cell module becomes constant. Therefore, if the current and voltage characteristics of multiple fuel cell modules deviate, the output of a fuel cell module with lower characteristics may not be extracted due to the constant voltage characteristic of parallel circuits. Thus, in this case, the optimal combination of fuel cell stacks constituting the fuel cell modules is particularly crucial.

[0009] The present invention was made in view of the above circumstances, and its object is to provide a method for assembling fuel cell stacks, which can determine a better combination of fuel cell stacks constituting a fuel cell module.

[0010] [Technical means to solve the problem]

[0011] (1) The method for assembling fuel cell stacks of the present invention uses an inspection device (e.g., inspection device 2 described later) to determine the combination of multiple fuel cell stacks (e.g., fuel cell stack 12 described later) constituting a fuel cell system (e.g., fuel cell system 1 described later), wherein the fuel cell system includes multiple fuel cell modules (e.g., fuel cell module 11 described later), each of the fuel cell modules having the aforementioned fuel cell stacks connected in series and connected in parallel with each other; the aforementioned inspection device includes: an output acquisition unit (e.g., output acquisition unit 21 described later), for the aforementioned multiple fuel cell stacks Each of the aforementioned fuel cell stacks acquires its own output value; a degradation estimation unit (e.g., degradation estimation unit 22 described later) estimates the future degradation degree for each of the aforementioned fuel cell stacks; and a future output estimation unit (e.g., future output estimation unit 23 described later) estimates the future output value as the output value after a predetermined period for each of the aforementioned fuel cell stacks based on the future degradation degree estimated by the aforementioned degradation estimation unit; and, based on the difference between the respective output values ​​of the aforementioned fuel cell stacks and the difference between the respective future output values ​​of the aforementioned fuel cell stacks, determines the combination of the aforementioned fuel cell stacks.

[0012] In the fuel cell stack combination method of the invention of (1), the combination of multiple fuel cell stacks is determined based on the difference between the output values ​​of each of the multiple fuel cell stacks and the difference between the future output values ​​of each of the multiple fuel cell stacks estimated based on future degradation. Therefore, according to the invention of (1), compared with the case where the combination of multiple fuel cell stacks is determined solely based on the difference between the output values ​​of each of the multiple fuel cell stacks, a better combination that takes into account the future degradation of the fuel cell stacks can be determined.

[0013] In the combination method of the fuel cell stack of the invention of (2)(1), for each of the aforementioned multiple fuel cell modules, the output values ​​of the aforementioned multiple fuel cell stacks of the fuel cell module are accumulated to obtain the output value of the fuel cell module. For each of the aforementioned multiple fuel cell modules, the future output values ​​of the aforementioned multiple fuel cell stacks of the fuel cell module are accumulated to estimate the future output value of the fuel cell module. Based on the difference between the output values ​​of the aforementioned multiple fuel cell modules and the difference between the future output values ​​of the aforementioned multiple fuel cell modules, the combination of the aforementioned multiple fuel cell stacks is determined.

[0014] According to the method of combining fuel cell stacks of the invention of (2), the output value and future output value are obtained in units of fuel cell modules having multiple fuel cell stacks connected in series, and the combination of multiple fuel cell stacks is determined based on these values, so that the combination of fuel cell stacks such that the fuel cell modules are the optimal combination of each other can be determined.

[0015] In the combination method of the fuel cell stacks of the invention (3)(1), the combination of the aforementioned fuel cell stacks that minimizes the total output value can also be determined based on the difference between the maximum and minimum output values ​​of the aforementioned multiple fuel cell stacks and the difference between the maximum and minimum future output values ​​of the aforementioned multiple fuel cell stacks.

[0016] According to the fuel cell stack combination method of the invention of (3), the combination of multiple fuel cell stacks with the minimum total output value is determined based on the difference between the maximum and minimum output values ​​of multiple fuel cell stacks and the difference between the maximum and minimum future output values ​​of multiple fuel cell stacks. Thus, the optimal combination of fuel cell stacks can be determined to ensure a wider range of power extraction, effectively utilize each fuel cell stack, and reduce the deviation of the power load ratio during operation, thereby contributing to a long lifespan.

[0017] (4) The combination method of the fuel cell stack of the present invention can also determine the combination of the aforementioned fuel cell stacks where the sum of the difference between the maximum and minimum output values ​​of the aforementioned multiple fuel cell modules and the difference between the maximum and minimum future output values ​​of the aforementioned multiple fuel cell modules reaches the minimum.

[0018] According to the combination method of fuel cell stacks of the invention of (4), the combination of multiple fuel cell stacks that minimizes the difference between the maximum and minimum output values ​​of multiple fuel cell modules and the sum of the difference between the maximum and minimum future output values ​​of multiple fuel cell modules can be determined. Thus, the optimal combination of fuel cell stacks can be determined to ensure a wider range of power extraction, effectively utilize each fuel cell stack, and reduce the deviation of the power load ratio during operation, thereby contributing to a long lifespan.

[0019] In the combination method of the fuel cell stack of the invention of (5)(3), for each of the aforementioned multiple fuel cell modules, the output values ​​of the aforementioned multiple fuel cell stacks of each fuel cell module are accumulated to obtain the output value of the fuel cell module. For each of the aforementioned multiple fuel cell modules, the future output values ​​of the aforementioned multiple fuel cell stacks of each fuel cell module are accumulated to estimate the future output value of the fuel cell module. The combination of the aforementioned multiple fuel cell stacks in which the difference between the maximum and minimum values ​​of the output values ​​of the aforementioned multiple fuel cell modules is smaller than the difference between the maximum and minimum values ​​of the future output values ​​of the aforementioned multiple fuel cell modules is determined.

[0020] According to the fuel cell stack combination method of the invention of (5), the combination of multiple fuel cell stacks in which the difference between the maximum and minimum values ​​of the output values ​​of multiple fuel cell modules is smaller than the difference between the maximum and minimum values ​​of the future output values ​​of multiple fuel cell modules can be determined, thus determining the optimal combination of fuel cell stacks that ensures a wider range of power extraction, effectively utilizes each fuel cell stack, and reduces the deviation of the power load ratio during operation, thus contributing to a long lifespan.

[0021] In the combination method of fuel cell stacks of the invention (6)(1), the aforementioned multiple fuel cell stacks may be classified based on the difference between the output value of the fuel cell stack and the future output value of the fuel cell stack, and the combination of the aforementioned fuel cell stacks may be determined based on the respective levels of the aforementioned multiple fuel cell stacks.

[0022] According to the fuel cell stack combination method of the invention (6), the combination of fuel cell stacks is determined based on the levels of multiple fuel cell stacks obtained by classifying the difference between the output value and the future output value, thus determining a better combination of fuel cell stacks. For example, fuel cell modules composed of levels with small differences can be used for applications with long life cycles, while fuel cell modules composed of levels with large differences can be used for applications with short life cycles, thus achieving optimal differentiation and use.

[0023] In the method of combining fuel cell stacks of any one of the inventions (7)(1) to (6), among the aforementioned plurality of fuel cell modules, at least one of the output values ​​of the aforementioned plurality of fuel cell stacks connected in series may be different from the others.

[0024] According to the fuel cell stack assembly method of the invention (7), at least one of the output values ​​of the multiple fuel cell stacks connected in series may differ from the others, thus allowing the use of second-hand products or products from other companies with different specifications as part of the multiple fuel cell stacks. Therefore, the range of fuel cell stacks to choose from is broadened, allowing for the determination of a more optimal combination of fuel cell stacks.

[0025] In the method of assembling a fuel cell stack of any one of the inventions (8)(1) to (7), the aforementioned predetermined period may also be determined based on the usage period or purpose of the aforementioned fuel cell stack.

[0026] According to the method of combining fuel cell stacks of the invention of (8), the predetermined period is determined based on the usage period or purpose of the fuel cell stack, and thus a better combination of fuel cell stacks can be determined.

[0027] [The effects of the invention]

[0028] According to the present invention, a more optimal combination of fuel cell stacks constituting a fuel cell module can be determined. Attached Figure Description

[0029] Figure 1 This is a block diagram illustrating the structure of a fuel cell system and inspection device for implementing a fuel cell stack assembly method according to an embodiment of the present invention.

[0030] Figure 2 A flowchart illustrating the assembly method of a fuel cell stack according to an embodiment of the present invention.

[0031] Figure 3A A graph showing the current and voltage characteristics of a fuel cell stack.

[0032] Figure 3B This is a graph illustrating the reduction in output of a fuel cell stack due to years of degradation.

[0033] Figure 4A This diagram illustrates whether the fuel cell stack assembly is good or bad, showing a case of poor fuel cell stack assembly.

[0034] Figure 4B This is a schematic diagram illustrating whether a fuel cell stack is well-assembled, showing a case where the fuel cell stack is well-assembled.

[0035] Figure 5A This diagram illustrates whether the fuel cell stack assembly is good or bad, showing a case of poor fuel cell stack assembly.

[0036] Figure 5B This is a schematic diagram illustrating whether a fuel cell stack is well-assembled, showing a case where the fuel cell stack is well-assembled.

[0037] Figure 6A A graph illustrating the output reduction of various fuel cell stacks due to years of degradation.

[0038] Figure 6B This is a schematic diagram showing a fuel cell system composed of various fuel cell stacks.

[0039] Figure 7 A schematic diagram illustrating a variation of a fuel cell system. Detailed Implementation

[0040] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0041] First, use Figure 1 The structure of the fuel cell system 1 and the inspection device 2, which implement the assembly method of the fuel cell stack 12 according to the embodiments of the present invention, will be described. Figure 1 This is a block diagram illustrating the structure of the fuel cell system 1 and the inspection device 2, which implement the assembly method of the fuel cell stack 12.

[0042] Figure 1The fuel cell system 1 shown is a system that connects multiple fuel cell modules 11 in parallel and does not have voltage control means such as an FCVCU (Fuel Cell Vehicle Control Unit). The voltages of each fuel cell module 11 are mutually constant. For this fuel cell system 1, it is required that the current and voltage characteristics of the multiple fuel cell modules 11 are without deviation. To meet this requirement, at the time of shipment of the fuel cell system 1, an inspection device 2 is used to determine a better combination of the multiple fuel cell stacks 12 constituting the fuel cell system 1. Then, an operator or a work robot (not shown) modifies the fuel cell stacks 12 in the manner determined by the inspection device 2.

[0043] Specifically, the fuel cell system 1 includes multiple fuel cell modules 11. Each of the multiple fuel cell modules 11 has multiple fuel cell stacks 12 connected in series. Furthermore, the multiple fuel cell modules 11 are connected in parallel with each other. In addition, in the case of... Figure 1 In the various diagrams, the fuel cell modules 11 are numbered from left to right as the first, second, ..., and the fuel cell stacks 12 are numbered from top to bottom as the first, second, ...

[0044] and, Figure 1 In this example, four fuel cell stacks 12 connected in series are used, but the number is not limited to four; it can also be two, three, or five or more. Furthermore, Figure 1 In the example, the number of multiple fuel cell modules 11 connected in parallel is 2, but it is not limited to 2, and can also be 3 or more.

[0045] Multiple fuel cell stacks 12 are managed by inspection device 2 in a mutually identifiable manner. Specifically, the multiple fuel cell stacks 12 are managed by inspection device 2 as follows: constituting a nth fuel cell module 11, and being a nth fuel cell stack 12 within that fuel cell module 11. For example, the first fuel cell stack 12 in the second fuel cell module 11 is managed by inspection device 2 with the number (2,1).

[0046] The inspection device 2 is used to determine the combination of multiple fuel cell stacks 12 constituting the fuel cell system 1 when the fuel cell system 1 is shipped. Specifically, the inspection device 2 includes an output acquisition unit 21, a degradation estimation unit 22, a future output estimation unit 23, a combination determination unit 24, and a result output unit 25.

[0047] The inspection device 2 is, for example, composed of a microprocessor having a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), and I / O (Input-Output) interfaces. The CPU executes programs read from the ROM or various storage units, reads information from the RAM, ROM, and various storage units during execution, writes information to the RAM and various storage units, and performs signal transmission and reception with a communication unit (not shown). Thus, through hardware and software (program) cooperation, the processing of this embodiment is realized.

[0048] The output acquisition unit 21 acquires the output value for each of the plurality of fuel cell stacks 12. Furthermore, the output acquisition unit 21 accumulates the output values ​​of each of the plurality of fuel cell stacks 12 in each of the plurality of fuel cell modules 11, thereby acquiring the output value of that fuel cell module 11.

[0049] The degradation estimation unit 22 estimates the future degradation degree for each of the multiple fuel cell stacks 12. Specifically, the degradation estimation unit 22 estimates the future degradation degree under long-term use based on the degradation degree caused by the extremely short period of use of each of the multiple fuel cell stacks 12, ensuring minimal degradation. The degradation degree can be obtained from data stored in a database as data corresponding to the output value, or it can be obtained from external big data.

[0050] The future output estimation unit 23 estimates the future output value of each of the multiple fuel cell stacks 12 based on the future degradation estimated by the degradation estimation unit 22, as the output value after a predetermined period. Furthermore, for each of the multiple fuel cell modules 11, the future output estimation unit 23 accumulates the future output values ​​of each of the multiple fuel cell stacks 12 within that fuel cell module 11, thereby estimating the future output value of that fuel cell module 11. The predetermined period is determined based on the usage period or purpose of the fuel cell stacks 12. The future output value can be obtained from data stored in a database as data corresponding to the degradation degree, or it can be obtained from external big data.

[0051] The combination decision unit 24 determines the combination of the multiple fuel cell stacks 12 based on the differences between the output values ​​of the multiple fuel cell stacks 12 and the differences between the future output values ​​of the multiple fuel cell stacks 12.

[0052] Specifically, the combination determination unit 24 determines the combination of multiple fuel cell stacks 12 based on the differences between the output values ​​of the multiple fuel cell modules 11 and the differences between the future output values ​​of the multiple fuel cell modules 11. More specifically, the combination determination unit 24 determines the combination of multiple fuel cell stacks 12 in which the sum of the differences between the maximum and minimum output values ​​of the multiple fuel cell modules 11 and the differences between the maximum and minimum future output values ​​of the multiple fuel cell modules 11 is minimized.

[0053] Alternatively, the combination determination unit 24 determines a combination of fuel cell stacks 12 whose total output value is minimized, based on the difference between the maximum and minimum output values ​​of the multiple fuel cell stacks 12 and the difference between the maximum and minimum future output values ​​of the multiple fuel cell stacks 12. More specifically, the combination determination unit 24 determines a combination of fuel cell stacks 12 whose difference between the maximum and minimum output values ​​of the multiple fuel cell modules 11 is smaller than the difference between the maximum and minimum future output values ​​of the multiple fuel cell modules 11.

[0054] Alternatively, the combination decision unit 24 classifies the multiple fuel cell stacks 12 based on the difference between the output value of the fuel cell stack 12 and the future output value of the fuel cell stack 12, and determines the combination of the fuel cell stacks 12 based on the respective levels of the multiple fuel cell stacks.

[0055] The result output unit 25 is a screen that outputs information to the operator or a communication means that outputs signals to the work robot (not shown). The result output unit 25 outputs the combination of fuel cell stacks 12 determined by the combination determination unit 24 to the operator or the work robot (not shown). For example, if the combination of fuel cell stacks 12 determined by the combination determination unit 24 can be achieved by mutually modifying fuel cell stacks 12 numbered (2,1) and (1,2), the result output unit 25 outputs the following: an instruction to mutually modify fuel cell stacks 12 numbered (2,1) and (1,2). Then, the operator or the work robot (not shown) modifies the fuel cell stacks 12 in the manner that the result output unit 25 outputs.

[0056] Next, use Figure 2 The process of assembling the fuel cell stack 12 according to an embodiment of the present invention will be described. Figure 2 A flowchart illustrating the assembly method of fuel cell stack 12.

[0057] Figure 2 The fuel cell stack 12 shown (refer to) Figure 1 The combination method is to use inspection device 2 (refer to) Figure 1To determine the composition of the fuel cell system 1 (refer to) Figure 1 Multiple fuel cell stacks 12 (refer to) Figure 1 The method of combining ) . Specifically, fuel cell stack 12 (refer to Figure 1 The combination method includes output acquisition step S11, degradation estimation step S12, future output estimation step S13, combination decision step S14, result output step S15 and modification step S16.

[0058] Output acquisition step S11 is output acquisition unit 21 (refer to) Figure 1 For multiple fuel cell stacks 12 (refer to) Figure 1 Each module acquires its own output value, and for multiple fuel cell modules 11 (refer to...) Figure 1 Each step involves obtaining the output value. After the output acquisition step S11, the degradation estimation step S12 is initiated.

[0059] Degradation estimation step S12 is degradation estimation unit 22 (refer to) Figure 1 For multiple fuel cell stacks 12 (refer to) Figure 1 Each step estimates the future degradation level. After degradation estimation step S12, the next step is to estimate the future output level S13.

[0060] Future output estimation step S13 is future output estimation unit 23 (refer to) Figure 1 For multiple fuel cell stacks 12 (refer to) Figure 1 Each module estimates its future output value, and for multiple fuel cell modules 11 (see reference 11) Figure 1 Each step involves estimating the future output value. After step S13, the process proceeds to step S14, which involves determining the combination of values.

[0061] Combination decision step S14 is the combination decision unit 24 (see reference). Figure 1 ) Determine multiple fuel cell stacks 12 (refer to) Figure 1 The steps for combining ( ) are as follows. After the combination determination step S14, the result output step S15 is performed.

[0062] The result output step S15 is the result output section 25 (refer to...). Figure 1 The output combination determines the fuel cell stack 12 determined in step S14 (see figure) for the operator or robot (illustration omitted). Figure 1 The steps involve combining the results. After step S15, the process proceeds to step S16, which involves outputting the results.

[0063] Modification step S16 involves modifying the fuel cell stack 12 (see figure) in a manner that combines the outputs of step S15 with those of an operator or robot (illustration omitted). Figure 1The modification steps are as follows. After modification step S16, the process is complete.

[0064] Next, use Figure 3A and Figure 3B For fuel cell stack 12 (reference) Figure 1 The current and voltage characteristics of the fuel cell stack 12 (refer to) due to years of degradation Figure 1 The output of ) is reduced to explain. Figure 3A To represent fuel cell stack 12 (refer to) Figure 1 The graph shows the current and voltage characteristics of the current. Figure 3B To indicate the fuel cell stack 12 (reference) due to years of deterioration Figure 1 The output of the graph is reduced.

[0065] like Figure 3A As shown, regarding fuel cell stack 12 (refer to...) Figure 1 Each fuel cell stack has predetermined current and voltage characteristics. Therefore, if the current and voltage characteristics of multiple fuel cell stacks deviate, it may be impossible to extract the output of the fuel cell stack that constitutes the low-performance fuel cell module due to the characteristics of a parallel circuit where the voltage is constant.

[0066] like Figure 3B As shown, fuel cell stack 12 (reference) Figure 1 The future output value decreases due to years of degradation. This future output value is estimated by the future output estimation unit 23. In this embodiment, the future output value estimated by the future output estimation unit 23 is also considered to determine the optimal combination of fuel cell stacks.

[0067] Next, use Figure 4A , Figure 4B , Figure 5A and Figure 5B The assembly of fuel cell stack 12 is explained to determine its quality. Figure 4A This is a schematic diagram illustrating whether the fuel cell stack 12 is assembled well or not, showing a case of poor assembly of the fuel cell stack 12. Figure 4B This is a schematic diagram illustrating whether the fuel cell stack 12 is well assembled, showing a case where the fuel cell stack 12 is well assembled. Figure 5A This is a schematic diagram illustrating whether the fuel cell stack 12 is assembled well or not, showing a case of poor assembly of the fuel cell stack 12. Figure 5B This is a schematic diagram illustrating whether the fuel cell stack 12 is well assembled, showing a case where the fuel cell stack 12 is well assembled.

[0068] like Figure 4AAs shown, when fuel cell stack 12 numbered (1,1) has good performance, fuel cell stack 12 numbered (1,2) has good performance, fuel cell stack 12 numbered (2,1) has average performance, and fuel cell stack 12 numbered (2,2) has average performance, the first fuel cell module 11 has a high output, while the second fuel cell module 11 has an average output. That is, the current and voltage characteristics of the multiple fuel cell modules 11 connected in parallel are deviated.

[0069] On the other hand, such as Figure 4B As shown, when fuel cell stack 12 numbered (1,1) has good performance, fuel cell stack 12 numbered (1,2) has average performance, fuel cell stack 12 numbered (2,1) has good performance, and fuel cell stack 12 numbered (2,2) has average performance, the output of the first fuel cell module 11 is good, and the output of the second fuel cell module 11 is also good. That is, at this time, the current and voltage characteristics of the multiple fuel cell modules 11 connected in parallel are without deviation.

[0070] Alternatively, if fuel cell stack 12 numbered (1,1) performs well, fuel cell stack 12 numbered (1,2) performs moderately, fuel cell stack 12 numbered (2,1) performs moderately, and fuel cell stack 12 numbered (2,2) performs well, then the first fuel cell module 11 will have a good output, and the second fuel cell module 11 will also have a good output. That is, in this case, the current and voltage characteristics of the multiple fuel cell modules 11 connected in parallel are without deviation.

[0071] Moreover, such as Figure 5A As shown, when the output and future output values ​​of fuel cell stack 12 numbered (1,1) are relatively high, the output and future output values ​​of fuel cell stack 12 numbered (1,2) are relatively high, the output and future output values ​​of fuel cell stack 12 numbered (2,1) are relatively low, and the output and future output values ​​of fuel cell stack 12 numbered (2,2) are relatively low, the first fuel cell module 11 has a high output, while the output of the second fuel cell module 11 is average. That is, the current and voltage characteristics of the multiple fuel cell modules 11 connected in parallel are deviated.

[0072] On the other hand, such as Figure 5BAs shown, when the output and future output values ​​of fuel cell stack 12 numbered (1,1) are relatively high, the output and future output values ​​of fuel cell stack 12 numbered (1,2) are relatively low, the output and future output values ​​of fuel cell stack 12 numbered (2,1) are relatively high, and the output and future output values ​​of fuel cell stack 12 numbered (2,2) are relatively low, the first fuel cell module 11 has a good output, and the second fuel cell module 11 also has a good output. That is, at this time, the current and voltage characteristics of the multiple fuel cell modules 11 connected in parallel are without deviation.

[0073] Alternatively, if the output and future output values ​​of fuel cell stack 12 numbered (1,1) are relatively high, the output and future output values ​​of fuel cell stack 12 numbered (1,2) are relatively low, the output and future output values ​​of fuel cell stack 12 numbered (2,1) are relatively low, and the output and future output values ​​of fuel cell stack 12 numbered (2,2) are relatively high, then the first fuel cell module 11 has a good output, and the second fuel cell module 11 also has a good output. That is, at this time, the current and voltage characteristics of the multiple fuel cell modules 11 connected in parallel are without deviation.

[0074] As mentioned above, if Figure 4A or Figure 5A As shown, if the current and voltage characteristics of multiple fuel cell stacks deviate, it may be impossible to extract the output of the fuel cell stack constituting the low-performance fuel cell module due to the characteristics of a parallel circuit where the voltage is constant. In contrast, this embodiment avoids this situation. Figure 4A or Figure 5A The combination of fuel cell stacks, as shown, with fuel cell modules that are misaligned in parallel, on the other hand, determines... Figure 4B or Figure 5B The combination of fuel cell stacks, as shown, consists of fuel cell modules connected in parallel without deviation.

[0075] Next, use Figure 6A and Figure 6B The output reduction of various fuel cell stacks 12 due to years of deterioration is explained, as well as the structure of the fuel cell system 1 composed of various fuel cell stacks 12. Figure 6A A graph illustrating the output reduction of various fuel cell stacks 12 due to years of degradation. Figure 6B This is a schematic diagram of a fuel cell system 1 composed of various fuel cell stacks 12.

[0076] Figure 6A The diagram shows various fuel cell stacks 12a to 12d (see reference). Figure 6BThe four lines represent the output reduction due to years of degradation. The first line from top to bottom, for example, indicates the high-output fuel cell stack 12a of our company's new product (see reference). Figure 6B The output value and future output value. The second line from the top, for example, represents the fuel cell stack 12b, which is a second-hand product of our company (see reference). Figure 6B The output value and future output value. The third line from the top, for example, represents the fuel cell stack 12c of our new product, which is a low-output product (see reference). Figure 6B The output value and future output value. The fourth line from the top, for example, represents a fuel cell stack 12d produced by another company (see reference). Figure 6B The output value and future output value of ).

[0077] Figure 6B The diagram illustrates a scenario where, among multiple fuel cell stacks connected in series, at least one has a different output value from the others. Fuel cell stack 12a (numbered (1,1)) is a high-output product of our company and is new. Fuel cell stack 12b (numbered (1,2)) is a low-output product of our company and is new. Fuel cell stack 12b (numbered (1,3)) is a low-output product of our company and is new. Fuel cell stack 12d (numbered (1,4)) is a product of another company. Fuel cell stack 12b (numbered (2,1)) is a low-output product of our company and is new. Fuel cell stack 12b (numbered (2,2)) is a low-output product of our company and is new. Fuel cell stack 12c (numbered (2,3)) is a product of our company and is a used product. Fuel cell stack 12a (numbered (2,4)) is a high-output product of our company and is new.

[0078] Thus, according to the combination method of the fuel cell stack 12, the combination of the multiple fuel cell stacks 12 is determined based on the difference between the output values ​​of the multiple fuel cell stacks 12 and the difference between the future output values ​​of the multiple fuel cell stacks 12. Therefore, compared with the case where the combination of the multiple fuel cell stacks is determined solely based on the difference between the output values ​​of the multiple fuel cell stacks, a better combination of the fuel cell stacks 12 can be determined.

[0079] Furthermore, according to the combination method of fuel cell stack 12, when the output value and future output value are obtained in units of fuel cell module 11 having multiple fuel cell stacks 12 connected in series, and the combination of multiple fuel cell stacks 12 is determined based on these values, a better combination of fuel cell stacks 12 can be determined.

[0080] Furthermore, according to the combination method of the fuel cell stack 12, when the combination of the multiple fuel cell stacks 12 is determined based on the difference between the maximum and minimum values ​​of the output values ​​of the multiple fuel cell stacks 12 and the difference between the maximum and minimum values ​​of the future output values ​​of the multiple fuel cell stacks 12, the following optimal combination of fuel cell stacks 12 can be determined: ensuring a wider range of power extraction, effectively utilizing each fuel cell stack, and reducing the deviation of the power load ratio during operation, thus contributing to a long lifespan.

[0081] Furthermore, according to the combination method of fuel cell stack 12, when determining the combination of multiple fuel cell stacks 12 that minimizes the difference between the maximum and minimum output values ​​of multiple fuel cell modules 11 and the sum of the differences between the maximum and minimum future output values ​​of multiple fuel cell modules 11, the following optimal combination of fuel cell stacks 12 can be determined: ensuring a wider range of power extraction, effectively utilizing each fuel cell stack, and reducing the deviation of the power load ratio during operation, thus contributing to a long lifespan.

[0082] Furthermore, according to the combination method of fuel cell stack 12, when determining the combination of multiple fuel cell stacks 12 in which the difference between the maximum and minimum values ​​of the output values ​​of multiple fuel cell modules 11 is smaller than the difference between the maximum and minimum values ​​of the future output values ​​of multiple fuel cell modules 11, the following optimal combination of fuel cell stacks 12 can be determined: ensuring a wider range of power extraction, effectively utilizing each fuel cell stack, and reducing the deviation of the power load ratio during operation, thus contributing to a long lifespan.

[0083] Furthermore, according to the combination method of the fuel cell stack 12, when the combination of the fuel cell stack 12 is determined based on the levels of each of the multiple fuel cell stacks 12, a more optimal combination of the fuel cell stacks 12 can be determined. For example, fuel cell modules composed of levels with smaller differences can be used for applications with long life cycles, while fuel cell modules composed of levels with larger differences can be used for applications with short life cycles, thus achieving optimal differentiated use.

[0084] Furthermore, according to the assembly method of fuel cell stack 12, at least one of the output values ​​of the multiple fuel cell stacks connected in series can differ from the others, thus allowing the use of second-hand products or products from other companies with different specifications as part of the multiple fuel cell stacks. Therefore, the range of fuel cell stacks to choose from is broadened, allowing for the determination of a more optimal combination of fuel cell stacks.

[0085] Furthermore, according to the combination method of the fuel cell stack 12, the predetermined period is determined based on the usage period or purpose of the fuel cell stack 12, thus a better combination of the fuel cell stack 12 can be determined.

[0086] Next, use Figure 7The structure of a variation of fuel cell system 1 will be explained. Figure 7 A schematic diagram illustrating a variation of fuel cell system 1.

[0087] for Figure 7 In the fuel cell system 1 shown, among the multiple fuel cell modules 11 connected in parallel, the difference between the output value and the future output value of the first fuel cell module 11 increases. The fuel cell system 1 includes a variable resistor 13 connected in series with the first fuel cell module 11 as an output adjustment means. In this variation of the fuel cell system 1, the variable resistor 13 prevents a decrease in output.

[0088] Furthermore, the present invention is not limited to the above-described embodiments, and variations and improvements within the scope of achieving the objectives of the present invention are included in the present invention.

[0089] For example, in this embodiment, the case of modifying the fuel cell stack 12 assembled into the fuel cell system 1 based on the inspection results of the fuel cell system 1 is described as an example. However, the present invention is not limited to this. It is also possible to inspect the fuel cell system 1 and inspect the replacement fuel cell stack 12, thereby removing the fuel cell stack 12 already provided in the fuel cell system 1 and assembling the replacement fuel cell stack 12.

[0090] Alternatively, in this embodiment, the case of modifying the fuel cell stack 12 incorporated into the fuel cell system 1 based on the inspection results of the fuel cell system 1 is described as an example. However, the present invention is not limited to this. It is also possible to inspect the fuel cell stack 12 removed from the fuel cell system 1 or the replacement fuel cell stack 12 and incorporate them.

[0091] Alternatively, in this embodiment, the combination of the fuel cell stack 12 is determined by the combination determination unit 24 constituting the inspection device 2, but the combination of the fuel cell stack 12 can also be determined by the operator based on the output of the inspection results of the inspection device 2.

[0092] Figure Labels

[0093] 1: Fuel Cell System

[0094] 11: Fuel Cell Module

[0095] 12, 12a~12d: Fuel cell stack

[0096] 13: Variable resistor

[0097] 2: Inspection device

[0098] 21: Output Acquisition Department

[0099] 22: Deterioration estimation part

[0100] 23: Future Output Probability Department

[0101] 24: Combination Decision Department

[0102] 25: Result Output Section

[0103] S11: Output Acquisition Steps

[0104] S12: Degradation estimation steps

[0105] S13: Future Output Estimation Steps

[0106] S14: Combination Decision Steps

[0107] S15: Result Output Steps

[0108] S16: Modification Steps

Claims

1. A method for assembling fuel cell stacks, using an inspection device to determine the combination of multiple fuel cell stacks constituting a fuel cell system. in, The fuel cell system has multiple fuel cell modules, each of which has the aforementioned multiple fuel cell stacks connected in series and connected in parallel with each other. The aforementioned inspection device includes: The output acquisition unit acquires the output values ​​for each of the aforementioned multiple fuel cell stacks; The degradation estimation department estimates the future degradation degree for each of the aforementioned fuel cell stacks; and, The future output estimation unit, for each of the aforementioned fuel cell stacks, estimates a future output value as the output value after a predetermined period, based on the future degree of degradation estimated by the aforementioned degradation estimation unit. For each of the aforementioned fuel cell modules, the output values ​​of the various fuel cell stacks within that module are accumulated to obtain the output value of that fuel cell module. For each of the aforementioned fuel cell modules, the future output values ​​of each of the aforementioned fuel cell stacks are accumulated to estimate the future output value of the fuel cell module. The combination of the aforementioned fuel cell stacks that minimizes the sum of the difference between the maximum and minimum output values ​​of the aforementioned multiple fuel cell modules and the difference between the maximum and minimum future output values ​​of the aforementioned multiple fuel cell modules.

2. The method for assembling a fuel cell stack according to claim 1, wherein, The aforementioned predetermined period is determined based on the usage period or purpose of the aforementioned fuel cell stack.

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