Fuel cell plate structure, fuel cell unit and fuel cell stack

Abstract

The present invention belongs to the technical field of fuel cells, and discloses a fuel cell plate structure, a fuel cell unit and a fuel cell stack. Among them, the first plate of the fuel cell plate structure is provided with a first serpentine flow field; the second plate is provided with a second serpentine flow field corresponding to the first serpentine flow field; both the first serpentine flow field and the second serpentine flow field are periodic flow fields, and the serpentine period value of the first serpentine flow field is not equal to the serpentine period value of the second serpentine flow field; among the serpentine period value of the first serpentine flow field and the serpentine period value of the second serpentine flow field, the ratio of the smaller one to the larger one is A, and 0.7 ≤ A < 1. It can flexibly adjust the retention effect and discharge effect of the generated water in different reaction regions according to the water content of the gas in different reaction regions of the entire flow field, and the fuel cell plate structure has good versatility and low processing difficulty, can avoid affecting the pressure borne by the membrane electrode structure, and improves the working performance and service life of the fuel cell stack.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and in particular to a fuel cell plate structure, a fuel cell unit, and a fuel cell stack. Background Art

[0002] A fuel cell is a device that directly converts the chemical energy of a fuel into electrical energy. It has the advantages of high energy conversion efficiency and environmental friendliness, and is a clean energy technology with great development prospects. Among them, the fuel cell plate structure is the core component of the fuel cell, which plays important roles such as supporting the overall structure, separating fuel gas and oxidizing gas, and collecting and conducting current. Therefore, optimizing the fuel cell plate structure is an important way to improve the working performance and service life of the fuel cell.

[0003] Currently, in the prior art, in order to reduce the phenomenon that the generated water in the electrochemical reaction accumulates and blocks in the downstream of the cathode side, the anode flow field and the cathode flow field are usually set as wavy flow fields, variable cross-section flow fields, etc., and parameters such as the groove ridge width ratio of the flow field and the depth of the flow field are adjusted. Although it can reduce the phenomenon that the generated water in the electrochemical reaction accumulates and blocks in the downstream of the cathode side, there is still room for improvement. Secondly, for the variable cross-section flow field and the method of adjusting parameters such as the groove ridge width ratio of the flow field and the depth of the flow field, the processing difficulty is high, the plate is easy to warp, and it will affect the pressure borne by the membrane electrode during the later use process, resulting in poor working performance and service life of the fuel cell. Among them, in order to reduce the phenomenon of generated water accumulation and blockage, the application number is: CN201810743055.X, and the application name is: A fuel cell bipolar plate, which further improves the wavy flow field, such as Figure 1 shown, it sets both the anode flow field reaction area and the cathode flow field reaction area as wavy flow fields, sets the anode flow field reaction area and the cathode flow field reaction area to be reversely symmetric, and sets the period of the anode flow field reaction area and the period of the cathode flow field reaction area to be an integer multiple relationship. However, Figure 1 it can be clearly seen that along the extension direction of the anode flow field reaction area, the overlapping area of the anode flow field reaction area and the cathode flow field reaction area basically does not change. Therefore, although it combines the characteristics of the wavy shape and the parallelism of multiple flow channels, it does not substantially improve the discharge effect and retention effect of the generated water in the entire flow field. Therefore, the discharge effect and retention effect of the generated water in the entire flow field still need to be further improved. Summary of the Invention

[0004] The purpose of the present invention is to provide a fuel cell plate structure, a fuel cell unit, and a fuel cell stack to solve the above problems existing in the fuel cell plate structure in the prior art.

[0005] To achieve this purpose, the present invention adopts the following technical solutions:

[0006] Fuel cell plate structure, including a first plate and a second plate distributed on both sides of the membrane electrode structure:

[0007] The first plate is provided with a first serpentine flow field; the second plate is provided with a second serpentine flow field corresponding to the first serpentine flow field;

[0008] Both the first serpentine flow field and the second serpentine flow field are periodic flow fields, and the serpentine period value of the first serpentine flow field is not equal to the serpentine period value of the second serpentine flow field; among the serpentine period value of the first serpentine flow field and the serpentine period value of the second serpentine flow field, the ratio of the smaller one to the larger one is A, and 0.7 ≤ A < 1.

[0009] As a preferred solution of the above fuel cell plate structure, the first serpentine flow field includes a plurality of first serpentine flow channels spaced apart along a first direction, and the second serpentine flow field includes a plurality of second serpentine flow channels spaced apart along the first direction;

[0010] Both the first serpentine flow channel and the second serpentine flow channel extend along a second direction, the first direction is perpendicular to the second direction, and both the first direction and the second direction are parallel to the plane of the first plate in contact with the membrane electrode structure.

[0011] As a preferred solution of the above fuel cell plate structure, the first fluctuation central axis of the first serpentine flow channel and the second fluctuation central axis of the second serpentine flow channel are both parallel to the second direction.

[0012] As a preferred solution of the above fuel cell plate structure, the first serpentine flow channel is a periodic smooth waveform flow channel, or the first serpentine flow channel is a periodic broken line waveform flow channel;

[0013] The second serpentine flow channel is a periodic smooth waveform flow channel, or the second serpentine flow channel is a periodic broken line waveform flow channel.

[0014] As a preferred solution of the above fuel cell plate structure, the number of the first serpentine flow fields is multiple, and the multiple first serpentine flow fields are spaced apart along the second direction and are connected in sequence; the number of the second serpentine flow fields is multiple, and the multiple second serpentine flow fields are spaced apart along the second direction and are connected in sequence; the multiple first serpentine flow fields and the multiple second serpentine flow fields are arranged in one-to-one correspondence; the second direction is parallel to the plane of the first plate in contact with the membrane electrode structure.

[0015] As a preferred solution of the above fuel cell plate structure, the serpentine period values of the multiple first serpentine flow fields are all equal; the serpentine period values of the multiple second serpentine flow fields are all equal.

[0016] As a preferred embodiment of the above fuel cell plate structure, along the second direction, the meandering period values of the plurality of first meandering flow fields gradually change, and / or the meandering period values of the plurality of second meandering flow fields gradually change.

[0017] As a preferred embodiment of the above fuel cell plate structure, when the meandering period values of the plurality of first meandering flow fields gradually change and the meandering period values of the plurality of second meandering flow fields gradually change, the change trend of the meandering period values of the plurality of first meandering flow fields is the same as the change trend of the meandering period values of the plurality of second meandering flow fields.

[0018] A fuel cell unit includes the membrane electrode structure and also includes the above fuel cell plate structure. The first plate, the membrane electrode structure, and the second plate are sequentially stacked or adhesively encapsulated to form the fuel cell unit.

[0019] A fuel cell stack includes a plurality of the above fuel cell units, and the plurality of fuel cell units are sequentially stacked.

[0020] Advantages of the present invention:

[0021] The present invention provides a fuel cell plate structure, a fuel cell unit, and a fuel cell stack. Among them, the fuel cell plate structure includes a first plate and a second plate distributed on both sides of the membrane electrode structure. The first plate is provided with a first meandering flow field; the second plate is provided with a second meandering flow field corresponding to the first meandering flow field; both the first meandering flow field and the second meandering flow field are periodic flow fields, and the meandering period value of the first meandering flow field is not equal to the meandering period value of the second meandering flow field; among the meandering period value of the first meandering flow field and the meandering period value of the second meandering flow field, the ratio of the smaller one to the larger one is A, and 0.7 ≤ A < 1.

[0022] The first meandering flow field and the second meandering flow field of the fuel cell plate structure are both periodic flow fields. Therefore, the first meandering flow field is arranged on the first plate in a periodic swinging manner, and the second meandering flow field is also arranged on the second plate in a periodic swinging manner. By setting the distribution positions of the first meandering flow field and the second meandering flow field to correspond to each other, the meandering period value of the first meandering flow field is not equal to the meandering period value of the second meandering flow field. Moreover, among the meandering period value of the first meandering flow field and the meandering period value of the second meandering flow field, the ratio of the smaller one to the larger one is A, where 0.7 ≤ A < 1, so that the first meandering flow field and the second meandering flow field can form a first type of path distribution form and a second type of path distribution form. The first type of path distribution form is the part where the flow paths of the first meandering flow field and the second meandering flow field are substantially the same, and the second type of path distribution form is the part where the flow paths of the first meandering flow field and the second meandering flow field are substantially staggered. It can be understood that for a single first type of path distribution form and a single second type of path distribution form, the first type of path distribution form makes the overlapping area of the first meandering flow field and the second meandering flow field larger, thus making the retention effect of the generated water in the electrochemical reaction better, and the second type of path distribution form makes the overlapping area of the first meandering flow field and the second meandering flow field smaller, thus making the retention effect of the generated water in the electrochemical reaction better. Thus, on the basis of reducing the processing difficulty of the first plate and the second plate, the retention effect and the discharge effect of the generated water in the local reaction area of the entire flow field can be effectively improved.

[0023] Secondly, the meandering period value of the first meandering flow field is set to be unequal to the meandering period value of the second meandering flow field, and the ratio of the smaller one to the larger one of the meandering period value of the first meandering flow field and the meandering period value of the second meandering flow field is A, 0.7≤A<1, so that along the extension direction of the first meandering flow field, the proportion of the portion where the flow paths formed by the first meandering flow field and the second meandering flow field are roughly consistent, and the proportion of the portion where the flow paths formed by the first meandering flow field and the second meandering flow field are roughly intertwined can be adjusted according to the actual working conditions, thereby reducing the processing difficulty of the first electrode plate and the second electrode plate, and effectively improving the retention effect and discharge effect of the generated water in the entire flow field in different reaction areas. Taking the case that the upstream of the first meandering flow field and the upstream of the second meandering flow field are distributed on the same side, the meandering period value of the first meandering flow field and the meandering period value of the second meandering flow field are set to be unequal, and the ratio of the smaller one to the larger one of the meandering period value of the first meandering flow field and the meandering period value of the second meandering flow field is A, 0.7≤A<1, so that the proportion of the portion of the flow path formed by the first meandering flow field and the second meandering flow field that is roughly consistent along the extension direction of the first meandering flow field can gradually decrease from upstream to downstream, or gradually increase from upstream to downstream, or first increase and then decrease from upstream to downstream, or first decrease and then increase from upstream to downstream. Among them, for the portion of the flow path formed by the first meandering flow field and the second meandering flow field that is roughly consistent, the retention effect of the generated water of the electrochemical reaction is better, which is suitable for the reaction area with a low water content in the reaction gas; for the portion of the flow path formed by the first meandering flow field and the second meandering flow field that is roughly staggered, the discharge effect of the generated water of the electrochemical reaction is better, which is suitable for the reaction area with a high water content in the reaction gas. Therefore, in the reaction area where the discharge effect of the generated water needs to be improved, the proportion of the parts where the flow paths are roughly staggered is relatively increased, and in the area where the retention effect of the generated water needs to be improved, the proportion of the parts where the flow paths are roughly consistent is relatively increased.

[0024] Therefore, the fuel cell plate structure can not only effectively reduce the phenomenon of accumulation and clogging of water generated by electrochemical reactions downstream of the cathode side in the prior art, but also can effectively adjust the retention and discharge effects of the generated water in different reaction areas in the entire flow field according to actual working conditions, thereby effectively improving the working performance and service life of the fuel cell stack; secondly, the fuel cell plate structure can be applied to fuel cell stacks with different characteristics, thereby improving the versatility of the fuel cell plate structure; secondly, compared with the prior art, the fuel cell plate structure has low processing difficulty, can effectively avoid plate warping and the like, and can effectively avoid affecting the pressure on the membrane electrode structure, thereby further improving the working performance and service life of the fuel cell stack.

[0025] The present invention also provides a fuel cell unit, which includes a membrane electrode structure and also includes the above-mentioned fuel cell plate structure. The first plate, the membrane electrode structure, and the second plate are sequentially stacked or adhesively encapsulated to form a fuel cell unit. By adopting the above-mentioned fuel cell plate structure, it is possible to effectively adjust the retention effect or discharge effect of the generated water in different reaction regions in the entire flow field according to the actual working conditions, thereby effectively improving the working performance and service life of the fuel cell unit; secondly, the processing difficulty of the fuel cell unit can be effectively reduced.

[0026] The present invention also provides a fuel cell stack, which includes a plurality of the above-mentioned fuel cell units, and the plurality of fuel cell units are sequentially stacked. By adopting the above-mentioned fuel cell unit, it is possible to effectively adjust the retention effect or discharge effect of the generated water in different reaction regions in the entire flow field according to the actual working conditions, thereby effectively improving the working performance and service life of the fuel cell stack; secondly, the processing difficulty of the fuel cell stack can be effectively reduced. Description of the Drawings

[0027] Figure 1 is the relative positional relationship between the anode flow field reaction region and the cathode flow field reaction region in the prior art;

[0028] Figure 2 is the relative positional relationship between the first meandering flow field and the second meandering flow field provided by a specific embodiment of the present invention Figure 1 ;

[0029] Figure 3 is the relative positional relationship between the first meandering flow field and the second meandering flow field provided by a specific embodiment of the present invention Figure 2 ;

[0030] Figure 4 is the relative positional relationship between the first meandering flow field and the second meandering flow field provided by a specific embodiment of the present invention Figure 3 ;

[0031] Figure 5 is the relative positional relationship between the first meandering flow field and the second meandering flow field provided by a specific embodiment of the present invention Figure 4 ;

[0032] Figure 6 is the relative positional relationship between the first meandering flow field and the second meandering flow field provided by a specific embodiment of the present invention Figure 5 ;

[0033] Figure 7 is a schematic structural diagram of the first meandering flow channel provided by a specific embodiment of the present invention;

[0034] Figure 8 is a schematic structural diagram of the second meandering flow channel provided by a specific embodiment of the present invention.

[0035] In the figure:

[0036] 110, Anode flow field reaction area; 120, Cathode flow field reaction area;

[0037] 1, First meandering flow field; 11, First meandering flow channel;

[0038] 2, Second meandering flow field; 21, Second meandering flow channel;

[0039] 3, First fluctuating central axis;

[0040] 4, Second fluctuating central axis. Specific embodiments

[0041] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. In addition, it should be noted that, for the sake of convenience of description, only the parts related to the present invention are shown in the drawings, rather than all the structures.

[0042] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] In the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features between them. Moreover, the first feature being "above", "above", and "on" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "below", and "under" the second feature includes the first feature being directly below and obliquely below the second feature, or simply indicating that the horizontal height of the first feature is lower than that of the second feature.

[0044] In the description of this embodiment, the orientation or positional relationships such as "above", "below", "right", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0045] Figure 1 It is the relative position relationship between the anode flow field reaction area 110 and the cathode flow field reaction area 120 in the prior art.

[0046] Figures 2 to 6 The part circled by the square box A is the part where the flow paths of the first meandering flow field 1 and the second meandering flow field 2 are roughly the same; this path distribution form is denoted as: the first type of path distribution form. Figures 2 to 6 The part circled by the square box B is the part where the flow paths of the first meandering flow field 1 and the second meandering flow field 2 roughly intersect; this path distribution form is denoted as: the second type of path distribution form. Figures 2 to 6 The ab direction in [it] is the first direction. Figures 2 to 6 The cd direction in [it] is the second direction.

[0047] Figure 7 In [it], T1 is the meandering period value of the first meandering flow channel 11, which is the projection length of one period of the first meandering flow channel 11 in the second direction, and corresponds to the meandering period value of the first meandering flow field 1. Figure 8 In [it], T2 is the meandering period value of the second meandering flow channel 21, which is the projection length of one period of the second meandering flow channel 21 in the second direction, and corresponds to the meandering period value of the second meandering flow field 2.

[0048] In the prior art, in order to reduce the phenomenon of the generated water in the electrochemical reaction accumulating and blocking downstream on the cathode side, the anode flow field and the cathode flow field are usually set as wavy flow fields, variable cross-section flow fields, etc., and parameters such as the groove ridge width ratio of the flow field and the depth of the flow field will be adjusted. Although it can reduce the phenomenon of the generated water in the electrochemical reaction accumulating and blocking downstream on the cathode side, there is still room for improvement; secondly, for the variable cross-section flow field and the method of adjusting parameters such as the groove ridge width ratio of the flow field and the depth of the flow field, the processing difficulty is high, the electrode plate is prone to warping, and it will affect the pressure borne by the membrane electrode during the later use process, resulting in poor working performance and service life of the fuel cell. Especially as Figure 1 As shown in [it], in a fuel cell bipolar plate in the prior art, both the anode flow field reaction area 110 and the cathode flow field reaction area 120 are set as wavy flow fields, the anode flow field reaction area 110 and the cathode flow field reaction area 120 are set to be reversely symmetric, and the periods of the anode flow field reaction area 110 and the cathode flow field reaction area 120 are set in an integer multiple relationship. But Figure 1 It can be clearly seen that along the extension direction of the anode flow field reaction area 110, the overlapping area of the anode flow field reaction area 110 and the cathode flow field reaction area 120 basically does not change. Therefore, although it combines the characteristics of the wavy shape and the parallelism of multiple flow channels, there is no substantial improvement in the discharge effect and retention effect of the generated water in the entire flow field. Therefore, the discharge effect and retention effect of the generated water in the entire flow field still need to be further improved.

[0049] Therefore, the present invention provides a fuel cell plate structure. Figures 2 to 6 As shown, the fuel cell plate structure includes a first plate and a second plate distributed on both sides of the membrane electrode structure, the first plate is provided with a first meandering flow field 1; the second plate is provided with a second meandering flow field 2 corresponding to the first meandering flow field 1; the first meandering flow field 1 and the second meandering flow field 2 are both periodic flow fields, and the meandering period value of the first meandering flow field 1 is not equal to the meandering period value of the second meandering flow field 2; among the meandering period value of the first meandering flow field 1 and the meandering period value of the second meandering flow field 2, the ratio of the smaller one to the larger one is A, 0.7≤A<1.

[0050] The first meandering flow field 1 and the second meandering flow field 2 of the fuel cell plate structure are both periodic flow fields, so the first meandering flow field 1 is periodically swung and arranged on the first plate, and the second meandering flow field 2 is also periodically swung and arranged on the second plate, by setting the distribution positions of the first meandering flow field 1 and the second meandering flow field 2 to correspond, the meandering period value of the first meandering flow field 1 is not equal to the meandering period value of the second meandering flow field 2, and the ratio of the smaller one to the larger one of the meandering period value of the first meandering flow field 1 and the meandering period value of the second meandering flow field 2 is A, 0.7≤A<1, so that the first meandering flow field 1 and the second meandering flow field 2 can form a first type of path distribution form and a second type of path distribution form. Distribution form: the first type of path distribution form is the part where the flow paths of the first meandering flow field 1 and the second meandering flow field 2 are roughly consistent, and the second type of path distribution form is the part where the flow paths of the first meandering flow field 1 and the second meandering flow field 2 are roughly intertwined. It can be understood that for a single first type of path distribution form and a single second type of path distribution form, the first type of path distribution form makes the overlapping area of ​​the first meandering flow field 1 and the second meandering flow field 2 larger, so that the retention effect of the generated water of the electrochemical reaction is better, and the second type of path distribution form makes the overlapping area of ​​the first meandering flow field 1 and the second meandering flow field 2 smaller, so that the retention effect of the generated water of the electrochemical reaction is better. Therefore, on the basis of reducing the processing difficulty of the first electrode plate and the second electrode plate, the retention effect and discharge effect of the generated water in the local reaction area in the entire flow field can be effectively improved.

[0051] Secondly, set the meandering period value of the first meandering flow field 1 to be unequal to that of the second meandering flow field 2, and among the meandering period values of the first meandering flow field 1 and the second meandering flow field 2, the ratio of the smaller one to the larger one is A, where 0.7 ≤ A < 1. Along the extension direction of the first meandering flow field 1, the proportion of the first type of path distribution form formed by the first meandering flow field 1 and the second meandering flow field 2, and the proportion of the second type of path distribution form formed can be adjusted adaptively according to the actual working conditions. Thus, on the basis of reducing the processing difficulty of the first electrode plate and the second electrode plate, the retention effect and discharge effect of the generated water in different reaction regions of the entire flow field can be effectively improved. Taking the example that the upstream of the first meandering flow field 1 and the upstream of the second meandering flow field 2 are distributed on the same side, set the meandering period value of the first meandering flow field 1 to be unequal to that of the second meandering flow field 2, and among the meandering period values of the first meandering flow field 1 and the second meandering flow field 2, the ratio of the smaller one to the larger one is A, where 0.7 ≤ A < 1, so that the proportion of the first type of path distribution form formed by the first meandering flow field 1 and the second meandering flow field 2 along the extension direction of the first meandering flow field 1 can gradually decrease from upstream to downstream (as shown in Figure 2 ), or can gradually increase from upstream to downstream (as shown in Figure 3 ), or can increase first and then decrease from upstream to downstream, or can decrease first and then increase from upstream to downstream. Among them, for the first type of path distribution form formed by the first meandering flow field 1 and the second meandering flow field 2, the retention effect of the generated water in the electrochemical reaction is better, which is suitable for the reaction region with a lower water content in the reaction gas; for the second type of path distribution form formed by the first meandering flow field 1 and the second meandering flow field 2, the discharge effect of the generated water in the electrochemical reaction is better, which is suitable for the reaction region with a higher water content in the reaction gas. Therefore, in the reaction region where the discharge effect of the generated water needs to be improved, relatively increase the proportion of the second type of path distribution form, and in the region where the retention effect needs to be improved, relatively increase the proportion of the first type of path distribution form.

[0052] Thus, this fuel cell electrode plate structure can not only effectively reduce the phenomenon of the accumulation and blockage of the generated water in the electrochemical reaction in the downstream of the cathode side in the prior art, but also effectively adjust the retention effect and discharge effect of the generated water in different reaction regions of the entire flow field according to the actual working conditions, so as to effectively improve the working performance and service life of the fuel cell stack; secondly, this fuel cell electrode plate structure can be applied to fuel cell stacks with different characteristics, improving the versatility of the fuel cell electrode plate structure; secondly, compared with the prior art, the processing difficulty of this fuel cell electrode plate structure is low, which can effectively avoid situations such as electrode plate warping, and can effectively avoid affecting the pressure borne by the membrane electrode structure, thereby further improving the working performance and service life of the fuel cell stack.

[0053] Specifically, Figure 2 exemplarily in it, the total meandering period value of the first meandering flow field 1 is the sum of 4 T1s, and the total meandering period value of the second meandering flow field 2 is the sum of 3.5 T2s; among the meandering period values of the first meandering flow field 1 and the second meandering flow field 2, the ratio of the smaller one to the larger one is 0.875. This makes the proportion of the first type of path distribution form formed by the first meandering flow field 1 and the second meandering flow field 2 gradually decrease from left to right; the proportion of the second type of path distribution form formed by the first meandering flow field 1 and the second meandering flow field 2 gradually increases from left to right. It can be understood that, Figure 2 in it, the phase angle at the leftmost side of the first meandering flow field 1 and the phase angle at the leftmost side of the second meandering flow field 2 are both approximately zero, Figure 2 in it, the phase difference between the leftmost side of the first meandering flow field 1 and the leftmost side of the second meandering flow field 2 is approximately zero; Figure 2 in it, the phase angle at the rightmost side of the first meandering flow field 1 is approximately 1440°, Figure 2 in it, the phase angle at the rightmost side of the second meandering flow field 2 is approximately 1260°, so the phase difference between the rightmost side of the first meandering flow field 1 and the rightmost side of the second meandering flow field 2 is approximately 180°.

[0054] More specifically, extend Figure 2 the rightmost side of the first meandering flow field 1 in it further along the second direction until the meandering period value of the first meandering flow field 1 is the sum of 8 T1s, and Figure 2 when the rightmost side of the second meandering flow field 2 in it is further extended along the second direction until the meandering period value is the sum of 7 T2s, the rightmost sides of the first meandering flow field 1 and the second meandering flow field 2 are distributed at the same position along the second direction; among the meandering period values of the first meandering flow field 1 and the second meandering flow field 2, the ratio of the smaller one to the larger one is 0.875. At this time, the phase angle at the rightmost side of the first meandering flow field 1 is approximately 2880°, the phase angle at the rightmost side of the second meandering flow field 2 is approximately 2520°, and the phase difference between the rightmost side of the first meandering flow field 1 and the rightmost side of the second meandering flow field 2 is 360°, which is equivalent to a phase difference of 0°.

[0055] More specifically, extend Figure 2 the rightmost side of the first meandering flow field 1 in it further along the second direction until the total meandering period value of the first meandering flow field 1 is the sum of 16 T1s, and Figure 2When the rightmost side of the second meandering flow field 2 in [[]] continues to extend along the second direction until the total meandering period value reaches the sum of 14 T2s, the rightmost sides of the first meandering flow field 1 and the second meandering flow field 2 are distributed at the same position along the second direction; among the meandering period values of the first meandering flow field 1 and the second meandering flow field 2, the ratio of the smaller one to the larger one is 0.875. At this time, the phase difference between the starting position of the ninth meandering period of the first meandering flow field 1 and the starting position of the eighth meandering period of the second meandering flow field 2 is approximately 360°, which is equivalent to a phase difference of 0°; the phase angle of the rightmost side of the first meandering flow field 1 is approximately 5760°, the phase angle of the rightmost side of the second meandering flow field 2 is approximately 5040°, and the phase difference between the rightmost sides of the first meandering flow field 1 and the second meandering flow field 2 is approximately 720°, which is equivalent to a phase difference of 0°.

[0056] It can be understood that when the total meandering period value of the first meandering flow field 1 is the sum of 16 T1s and the total meandering period value of the second meandering flow field 2 is the sum of 14 T2s, along the second direction, the phase difference between the first meandering flow field 1 and the second meandering flow field 2 gradually increases from zero to 720°.

[0057] Thus, for Figure 2 the first meandering flow field 1 and the second meandering flow field 2 in [[]], as the total meandering period values of the first meandering flow field 1 and the second meandering flow field 2 continuously increase, on the basis of defining the ratio of the smaller one to the larger one among the meandering period values of the first meandering flow field 1 and the second meandering flow field 2, the proportion of the first type of path distribution form formed by the first meandering flow field 1 and the second meandering flow field 2 along the extension direction of the first meandering flow field 1 first decreases and then increases from left to right.

[0058] Specifically, the upstream of the first meandering flow field 1 and the upstream of the second meandering flow field 2 are both distributed on the Figure 2 left side. Or, the upstream of the first meandering flow field 1 and the upstream of the second meandering flow field 2 are both distributed on the Figure 2 right side. Or, one of the upstream of the first meandering flow field 1 and the upstream of the second meandering flow field 2 is distributed on the Figure 2 left side, and the other is distributed on the Figure 2 right side.

[0059] Further specifically, for Figure 2 [[]], exemplarily, the upstream of the first meandering flow field 1 and the upstream of the second meandering flow field 2 are both distributed on the Figure 2 left side. Hydrogen is introduced into one of the first meandering flow field 1 and the second meandering flow field 2 from the upstream, and air is introduced into the other. The hydrogen and air undergo an electrochemical reaction under the action of the membrane electrode structure; as the reaction proceeds, along the flow direction of the hydrogen, the hydrogen flow rate gradually decreases, and the water content generated gradually increases. By adoptingFigure 2 In the distribution forms of the first meandering flow field 1 and the second meandering flow field 2, the proportion of the second type of path distribution form formed by the first meandering flow field 1 and the second meandering flow field 2 gradually increases from upstream to downstream, so that the discharge effect of the generated water is better. Thus, the phenomenon that the generated water in the electrochemical reaction in the prior art accumulates and blocks downstream on the cathode side is effectively reduced, and the retention effect and discharge effect of the generated water in different reaction regions in the entire flow field are effectively improved.

[0060] Specifically, Figure 3 Exemplarily in, the total meandering period value of the first meandering flow field 1 is the sum of 4 T1s, and the total meandering period value of the second meandering flow field 2 is the sum of 3.5 T2s; among the meandering period values of the first meandering flow field 1 and the second meandering flow field 2, the ratio of the smaller one to the larger one is 0.875. So that the proportion of the first type of path distribution form formed by the first meandering flow field 1 and the second meandering flow field 2 gradually increases from left to right; the proportion of the second type of path distribution form formed by the first meandering flow field 1 and the second meandering flow field 2 gradually decreases from left to right. It can be understood that Figure 3 In, the phase angle at the leftmost side of the first meandering flow field 1 and the phase angle at the leftmost side of the second meandering flow field 2 are both approximately zero, Figure 3 In, the phase difference between the leftmost side of the first meandering flow field 1 and the leftmost side of the second meandering flow field 2 is approximately zero; Figure 3 In, the phase angle at the rightmost side of the first meandering flow field 1 is approximately 1440°, Figure 3 In, the phase angle at the rightmost side of the second meandering flow field 2 is approximately 1260°, so the phase difference between the rightmost side of the first meandering flow field 1 and the rightmost side of the second meandering flow field 2 is approximately 180°.

[0061] It can be understood that for Figure 3 the first meandering flow field 1 and the second meandering flow field 2 in, with the continuous increase of the total meandering period value of the first meandering flow field 1 and the total meandering period value of the second meandering flow field 2, on the basis of limiting the ratio of the smaller one to the larger one among the meandering period values of the first meandering flow field 1 and the second meandering flow field 2, it can make the proportion of the first type of path distribution form formed by the first meandering flow field 1 and the second meandering flow field 2 along the extension direction of the first meandering flow field 1 increase first and then decrease from left to right. Exemplarily, continue to extend the rightmost side of Figure 3 the first meandering flow field 1 in the second direction until the total meandering period value of the first meandering flow field 1 is the sum of 8 T1s, and Figure 3When the rightmost side of the second meandering flow field 2 continues to extend along the second direction until the total meandering period value reaches the sum of 7 T2s, the rightmost sides of the first meandering flow field 1 and the second meandering flow field 2 are distributed at the same position along the second direction; among the meandering period values of the first meandering flow field 1 and the second meandering flow field 2, the ratio of the smaller one to the larger one is 0.875. At this time, the phase angle of the rightmost side of the first meandering flow field 1 is approximately 2880°, the phase angle of the rightmost side of the second meandering flow field 2 is approximately 2520°, and the phase difference between the rightmost sides of the first meandering flow field 1 and the second meandering flow field 2 is 360°, which is equivalent to a phase difference of 0°. This makes the proportion of the first type of path distribution formed by the first meandering flow field 1 and the second meandering flow field 2 along the extension direction of the first meandering flow field 1 increase first and then decrease from left to right.

[0062] Specifically, the upstream of the first meandering flow field 1 and the upstream of the second meandering flow field 2 are both distributed on Figure 3 the left side. Or, the upstream of the first meandering flow field 1 and the upstream of the second meandering flow field 2 are both distributed on Figure 3 the right side. Or, one of the upstream of the first meandering flow field 1 and the upstream of the second meandering flow field 2 is distributed on Figure 3 the left side, and the other is distributed on Figure 3 the right side.

[0063] Specifically, one of the first electrode plate and the second electrode plate is an anode electrode plate, and the other is a cathode electrode plate. Then, one of the first meandering flow field 1 and the second meandering flow field 2 is an anode meandering flow field, and the other is a cathode meandering flow field. Among them, the fuel cell electrode plate structure formed by the first electrode plate and the second electrode plate can be a metal bipolar plate, a graphite bipolar plate, a composite bipolar plate, etc.

[0064] It can be understood that the meandering period values of the first meandering flow field 1 and the second meandering flow field 2 can also be adaptively adjusted according to the actual working conditions, so that the ratio of the meandering period value of the first meandering flow field 1 to the meandering period value of the second meandering flow field 2 meets the usage requirements. Among them, the ratio of the smaller one to the larger one of the meandering period values of the first meandering flow field 1 and the second meandering flow field 2 can be 0.7, 0.725, 0.75, 0.775, 0.8, 0.825, 0.85, 0.875, 0.9, 0.925, 0.95, 0.96, or 0.975, etc.

[0065] It can be understood that by adjusting the meandering period value of the first meandering flow field 1 and the meandering period value of the second meandering flow field 2, the ratio A of the smaller one to the larger one among the meandering period value of the first meandering flow field 1 and the meandering period value of the second meandering flow field 2 falls within the range: 0.7 ≤ A < 1; adjusting the total meandering period value of the first meandering flow field 1 and the total meandering period value of the second meandering flow field 2; and adjusting the distribution positions of the first meandering flow field 1 and the second meandering flow field 2 in the entire flow field. Compared with the prior art, it is possible to effectively adjust the retention effect and discharge effect of the generated water in different reaction regions in the entire flow field according to the actual working condition requirements, and effectively improve the working performance and service life of the fuel cell stack.

[0066] Specifically, as Figures 2 - 8 shown, the first meandering flow field 1 includes a plurality of first meandering channels 11 spaced apart along a first direction, and the second meandering flow field 2 includes a plurality of second meandering channels 21 spaced apart along the first direction; both the first meandering channels 11 and the second meandering channels 21 extend along a second direction, the first direction is perpendicular to the second direction, and both the first direction and the second direction are parallel to the plane of the first bipolar plate in contact with the membrane electrode structure.

[0067] It can be understood that the number of the first meandering channels 11 in a single first meandering flow field 1 and the number of the second meandering channels 21 in the corresponding second meandering flow field 2 may be equal or unequal. When the number of the first meandering channels 11 in a single first meandering flow field 1 is equal to the number of the second meandering channels 21 in the corresponding second meandering flow field 2, the plurality of first meandering channels 11 and the plurality of second meandering channels 21 are arranged in one-to-one correspondence. In this embodiment, exemplarily, the number of the first meandering channels 11 is set to be equal to the number of the second meandering channels 21.

[0068] Furthermore, the channel width of the first meandering channels 11 and the channel width of the second meandering channels 21 may be equal or unequal. It can be set adaptively according to the actual working condition requirements.

[0069] Furthermore, along the first direction, the spacing between any two adjacent first meandering channels 11 and the spacing between any two adjacent second meandering channels 21 may be equal or unequal. It can be set adaptively according to the actual working condition requirements.

[0070] Preferably, as Figure 7 and Figure 8As shown, the first fluctuation central axis 3 of the first meandering flow channel 11 and the second fluctuation central axis 4 of the second meandering flow channel 21 are both parallel to the second direction. Along the first direction, it is possible to regularly adjust the proportion of the first type of path distribution form formed by the first meandering flow field 1 and the second meandering flow field 2 along the extension direction of the first meandering flow field 1, and the proportion of the second type of path distribution form along the extension direction of the first meandering flow field 1. Specifically, when multiple first meandering flow channels 11 and multiple second meandering flow channels 21 are arranged in one-to-one correspondence, it is convenient to adjust the distance value between the first fluctuation central axis 3 of the first meandering flow channel 11 and the second fluctuation central axis 4 of the second meandering flow channel 21, and it is also convenient to adjust the collinearity of the first fluctuation central axis 3 of the first meandering flow channel 11 and the second fluctuation central axis 4 of the second meandering flow channel 21. When the number of the first meandering flow channels 11 is different from the number of the second meandering flow channels 21, it is convenient to adjust the collinearity of a part of the first fluctuation central axes 3 and a part of the second fluctuation central axes 4, and it is also convenient to adjust the distance value between the first fluctuation central axis 3 and the second fluctuation central axis 4.

[0071] It can be understood that along the second direction, the height values of the wave crests and wave troughs of the first meandering flow channel 11 can be adjusted according to the actual working condition requirements. The height values of the wave crests and wave troughs of the second meandering flow channel 21 can be adjusted according to the actual working condition requirements. This can further adjust the retention effect and discharge effect of the generated water in different reaction regions in the entire flow field.

[0072] Specifically, as Figures 2 - 7 shown, the first meandering flow channel 11 is a periodic smooth waveform flow channel. Or, the first meandering flow channel 11 is a periodic broken-line waveform flow channel. Further, parameters such as the shape, depth, width, and cross-sectional area of the first meandering flow channel 11 can be adaptively adjusted according to the actual working condition requirements.

[0073] Specifically, as Figures 2 - 6 and Figure 8 shown, the second meandering flow channel 21 is a periodic smooth waveform flow channel. Or, the second meandering flow channel 21 is a periodic broken-line waveform flow channel. Further, parameters such as the shape, depth, width, and cross-sectional area of the second meandering flow channel 21 can be adaptively adjusted according to the actual working condition requirements.

[0074] Among them, as Figure 5 and Figure 6As shown, the number of the first meandering flow fields 1 is multiple, and the multiple first meandering flow fields 1 are distributed at intervals along the second direction and are connected in sequence; the number of the second meandering flow fields 2 is multiple, and the multiple second meandering flow fields 2 are distributed at intervals along the second direction and are connected in sequence; the multiple first meandering flow fields 1 and the multiple second meandering flow fields 2 are arranged in one-to-one correspondence; the second direction is parallel to the plane of the first plate in contact with the membrane electrode structure. With such an arrangement, it is possible to adaptively adjust the proportion change according to the changes in the retention demand and discharge demand of the generated water at various locations in the reaction flow field. Specifically, adaptively adjust the number of the first meandering flow fields 1 and the second meandering flow fields 2, the relative position form of each corresponding first meandering flow field 1 and second meandering flow field 2, the meandering period value of each corresponding first meandering flow field 1 and the meandering period value of the second meandering flow field 2, the total meandering period value of each corresponding first meandering flow field 1 and the total period value of the second meandering flow field 2, and the height values of the wave crests and wave troughs of the first meandering channels 11 and the height values of the wave crests and wave troughs of the second meandering channels 21 of each corresponding group, so that the formed proportion change can meet the changes in the retention demand and discharge demand of the generated water at various locations in the reaction flow field. Among them, the reaction flow field is formed by the first meandering flow field 1, the membrane electrode structure, and the second meandering flow field 2. The proportion change refers to the proportion change of the first type of path distribution form and the proportion change of the second path distribution form.

[0075] Thereby further improving the retention effect and discharge effect of the generated water in different reaction regions in the entire flow field, and thus being able to further improve the working performance and service life of the fuel cell stack.

[0076] It can be understood that when the number of the first meandering flow fields 1 is multiple, the number of the first meandering channels 11 in each first meandering flow field 1 is equal. When the number of the second meandering flow fields 2 is multiple, the number of the second meandering channels 21 in each second meandering flow field 2 is equal.

[0077] It can be understood that a part of the flow field distributed between the inlet end flow field and the outlet end flow field on the first plate can be set to be formed by at least one first meandering flow field 1. It is also possible to set all the flow fields distributed between the inlet end flow field and the outlet end flow field on the first plate to be formed by at least one first meandering flow field 1.

[0078] It can be understood that a part of the flow field distributed between the inlet end flow field and the outlet end flow field on the second plate can be set to be formed by at least one second meandering flow field 2. It is also possible to set all the flow fields distributed between the inlet end flow field and the outlet end flow field on the second plate to be formed by at least one second meandering flow field 2.

[0079] Specifically, when the number of both the first meandering flow fields 1 and the second meandering flow fields 2 is multiple, the setting methods of the multiple first meandering flow fields 1 and the multiple second meandering flow fields 2 are as follows:

[0080] Along the second direction, the meandering period values of the plurality of first meandering flow fields 1 gradually change, and / or, the meandering period values of the plurality of second meandering flow fields 2 gradually change. Or, the meandering period values of the plurality of first meandering flow fields 1 are all equal, and the meandering period values of the plurality of second meandering flow fields 2 are all equal.

[0081] Preferably, when the meandering period values of the plurality of first meandering flow fields 1 gradually change and the meandering period values of the plurality of second meandering flow fields 2 gradually change, the change trend of the meandering period values of the plurality of first meandering flow fields 1 is the same as the change trend of the meandering period values of the plurality of second meandering flow fields 2.

[0082] So that for fuel cell stacks with different characteristics, an optimal flow field arrangement form can be formed, thereby further improving the versatility of the fuel cell plate structure.

[0083] Specifically, Figure 4 Exemplarily, the number of both the first meandering flow fields 1 and the second meandering flow fields 2 is two. The two first meandering flow fields 1 are symmetrically distributed, and the two second meandering flow fields 2 are symmetrically distributed. The proportion of the first type of path distribution form formed by the first meandering flow fields 1 and the second meandering flow fields 2 gradually decreases from the middle to the left and right sides; the proportion of the second type of path distribution form formed by the first meandering flow fields 1 and the second meandering flow fields 2 gradually increases from the middle to the left and right sides. Among them, the upstream of the flow fields formed by the two first meandering flow fields 1 and the upstream of the flow fields formed by the two second meandering flow fields 2 are both distributed on Figure 5 the left side. Or, the upstream of the flow fields formed by the two first meandering flow fields 1 and the upstream of the flow fields formed by the two second meandering flow fields 2 are both distributed on Figure 5 the right side. Or, the upstream of the flow fields formed by the two first meandering flow fields 1 and the upstream of one of the flow fields formed by the two second meandering flow fields 2 are distributed on Figure 5 the left side, and the upstream of the other is distributed on Figure 5 the right side.

[0084] Specifically, Figure 5 and Figure 6 Exemplarily, the number of both the first meandering flow fields 1 and the second meandering flow fields 2 is two. From left to right, the meandering period values of the two first meandering flow fields 1 gradually increase, and from left to right, the meandering period values of the two second meandering flow fields 2 gradually increase. Among them, the proportion of the first type of path distribution form formed by the first meandering flow fields 1 and the second meandering flow fields 2 first gradually decreases and then gradually increases from left to right; the proportion of the second type of path distribution form formed by the first meandering flow fields 1 and the second meandering flow fields 2 first gradually increases and then gradually decreases from left to right. Among them, the upstream of the flow fields formed by the two first meandering flow fields 1 and the upstream of the flow fields formed by the two second meandering flow fields 2 are both distributed on Figure 6On the left side. Or, the upstream of the flow field formed by the two first meandering flow fields 1 and the upstream of the flow field formed by the two second meandering flow fields 2 are both distributed at Figure 6 On the right side. Or, the upstream of the flow field formed by the two first meandering flow fields 1 and the upstream of one of the flow fields formed by the two second meandering flow fields 2 are distributed at Figure 6 On the left side, and the upstream of the other is distributed at Figure 6 On the right side.

[0085] The present invention also provides a fuel cell unit, which includes a membrane electrode structure and also includes the above-mentioned fuel cell plate structure. The first plate, the membrane electrode structure, and the second plate are stacked or bonded and encapsulated in sequence to form a fuel cell unit. By adopting the above-mentioned fuel cell plate structure, it is possible to effectively adjust the retention effect and discharge effect of the generated water in different reaction regions in the entire flow field according to the actual working conditions, thereby effectively improving the working performance and service life of the fuel cell unit; secondly, it can effectively reduce the processing difficulty of the fuel cell unit.

[0086] The present invention also provides a fuel cell stack, which includes a plurality of the above-mentioned fuel cell units, and the plurality of fuel cell units are stacked in sequence. By adopting the above-mentioned fuel cell unit, it is possible to effectively adjust the retention effect and discharge effect of the generated water in different reaction regions in the entire flow field according to the actual working conditions, thereby effectively improving the working performance and service life of the fuel cell stack; secondly, it can effectively reduce the processing difficulty of the fuel cell stack.

[0087] Specifically, along the stacking direction of the plurality of fuel cell units, between any two adjacent fuel cell units, a coolant flow channel is formed between the first plate in one and the second plate in the other. Or, the plurality of fuel cell units form a plurality of fuel cell unit groups, and each fuel cell unit group includes at least two fuel cell units; along the stacking direction of the plurality of fuel cell units, between any two adjacent fuel cell unit groups, a coolant flow channel is formed between the first plate in one and the second plate in the other.

[0088] Obviously, the above-mentioned embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, various obvious changes, re-adjustments, and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A fuel cell plate structure, comprising a first plate and a second plate distributed on both sides of a membrane electrode structure, characterized in that: The first electrode plate is provided with a first meandering flow field (1); the second electrode plate is provided with a second meandering flow field (2) corresponding to the first meandering flow field (1); The first meandering flow field (1) and the second meandering flow field (2) are both periodic flow fields, and the meandering period value of the first meandering flow field (1) is not equal to the meandering period value of the second meandering flow field (2); the ratio of the smaller one to the larger one of the meandering period value of the first meandering flow field (1) and the meandering period value of the second meandering flow field (2) is A, and 0.7≤A<1; The first meandering flow field (1) and the second meandering flow field (2) form a first type of path distribution form and a second type of path distribution form, wherein the first type of path distribution form is a portion where the flow paths of the first meandering flow field (1) and the second meandering flow field (2) are roughly consistent, and the second type of path distribution form is a portion where the flow paths of the first meandering flow field (1) and the second meandering flow field (2) are roughly intertwined.

2. The fuel cell plate structure according to claim 1, characterized in that: The first meandering flow field (1) comprises a plurality of first meandering flow channels (11) spaced apart along a first direction, and the second meandering flow field (2) comprises a plurality of second meandering flow channels (21) spaced apart along the first direction; The first meandering flow channel (11) and the second meandering flow channel (21) both extend along a second direction, the first direction is perpendicular to the second direction, and the first direction and the second direction are both parallel to a plane on the first electrode plate that contacts the membrane electrode structure.

3. The fuel cell plate structure according to claim 2, characterized in that: The first undulating central axis (3) of the first serpentine flow channel (11) and the second undulating central axis (4) of the second serpentine flow channel (21) are both parallel to the second direction.

4. The fuel cell plate structure according to claim 2, characterized in that: The first meandering flow channel (11) is a periodic smooth wave-shaped flow channel, or the first meandering flow channel (11) is a periodic broken-line wave-shaped flow channel; The second meandering flow channel (21) is a periodic smooth wave-shaped flow channel, or the second meandering flow channel (21) is a periodic broken-line wave-shaped flow channel.

5. The fuel cell plate structure according to any one of claims 1 to 4, characterized in that: The number of the first meandering flow fields (1) is multiple, and the multiple first meandering flow fields (1) are spaced apart and connected in sequence along the second direction; the number of the second meandering flow fields (2) is multiple, and the multiple second meandering flow fields (2) are spaced apart and connected in sequence along the second direction; the multiple first meandering flow fields (1) and the multiple second meandering flow fields (2) are arranged in one-to-one correspondence; the second direction is parallel to the plane on the first electrode plate that contacts the membrane electrode structure.

6. The fuel cell plate structure according to claim 5, characterized in that: The meandering period values ​​of the plurality of the first meandering flow fields (1) are all equal; and the meandering period values ​​of the plurality of the second meandering flow fields (2) are all equal.

7. The fuel cell plate structure according to claim 5, characterized in that: Along the second direction, the meandering period values ​​of the plurality of the first meandering flow fields (1) gradually change, and / or the meandering period values ​​of the plurality of the second meandering flow fields (2) gradually change.

8. The fuel cell plate structure according to claim 7, characterized in that: When the meandering period values ​​of the plurality of first meandering flow fields (1) gradually change, and the meandering period values ​​of the plurality of second meandering flow fields (2) gradually change, the changing trend of the meandering period values ​​of the plurality of first meandering flow fields (1) is the same as the changing trend of the meandering period values ​​of the plurality of second meandering flow fields (2).

9. A fuel cell unit, comprising the membrane electrode structure, characterized in that: It also includes the fuel cell plate structure according to any one of claims 1 to 8, wherein the first plate, the membrane electrode structure and the second plate are stacked or bonded and packaged in sequence to form the fuel cell unit.

10. A fuel cell stack, characterized in that: The fuel cell unit comprises a plurality of fuel cell units as claimed in claim 9, wherein the plurality of fuel cell units are stacked in sequence.

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