阅读说明：本技术 燃料电池、燃料电池双极板及燃料电池双极板的流场结构 (Fuel cell, fuel cell bipolar plate and flow field structure of fuel cell bipolar plate ) 是由 靳宏建 刘冬安 姜炜 高辉强 肖学海 于 2020-05-13 设计创作，主要内容包括：本发明涉及一种燃料电池、燃料电池双极板及燃料电池双极板的流场结构,其中,燃料电池双极板的流场结构包括依次连通设置的进气口、通道和出气口,进气口和出气口分别设有端部流道；通道包括中间段以及两个分别设于中间段两端的分配段,中间段包括多条呈波浪形结构且平行设置的中间流道,分配段包括多条分配流道,分配流道对应连通于端部流道和各中间流道之间；相互连通的分配流道和中间流道之间的夹角呈钝角。该流场结构能够简化流场结构并可提高气体流速并可降低阻力降保证排水性能。(The invention relates to a fuel cell, a fuel cell bipolar plate and a flow field structure of the fuel cell bipolar plate, wherein the flow field structure of the fuel cell bipolar plate comprises an air inlet, a channel and an air outlet which are sequentially communicated, and the air inlet and the air outlet are respectively provided with an end part flow channel; the channel comprises a middle section and two distribution sections which are respectively arranged at two ends of the middle section, the middle section comprises a plurality of middle runners which are in a wave-shaped structure and are arranged in parallel, the distribution sections comprise a plurality of distribution runners, and the distribution runners are correspondingly communicated between the end runners and the middle runners; the included angle between the distribution flow channel and the middle flow channel which are communicated mutually is an obtuse angle. The flow field structure can simplify the flow field structure, improve the gas flow velocity, reduce the resistance drop and ensure the drainage performance.)

1. A flow field structure of a fuel cell bipolar plate is characterized by comprising an air inlet (1), a channel (3) and an air outlet (2) which are sequentially communicated, wherein the air inlet (1) and the air outlet (2) are respectively provided with an end flow channel (4);

the channel (3) comprises a middle section (31) and two distribution sections (32) which are respectively arranged at two ends of the middle section (31), the middle section (31) comprises a plurality of middle flow passages (311) which are in a wave-shaped structure and are arranged in parallel, the distribution sections (32) comprise a plurality of distribution flow passages (321), and the distribution flow passages (321) are correspondingly communicated between the end flow passages (4) and the middle flow passages (311);

the included angle between the distribution flow channel (321) and the middle flow channel (311) which are communicated with each other is an obtuse angle.

2. A flow field structure of a fuel cell bipolar plate according to claim 1, wherein the height of the gas inlet (1) is higher than the height of the gas outlet (2).

3. A flow field structure of a fuel cell bipolar plate according to claim 2, wherein two of said distribution sections (32) are symmetrically disposed about a central position of said middle section (31);

the end flow channel (4) arranged on the air inlet (1) and the end flow channel (4) arranged on the air outlet (2) are symmetrically arranged relative to the central position of the middle section (31).

4. A flow field structure of a fuel cell bipolar plate according to claim 2, wherein each of the distribution flow channels (321) is obliquely arranged, and an end of one side of the distribution flow channel (321) facing the gas inlet (1) is higher than an end of one side facing the gas outlet (2).

5. A flow field structure of a fuel cell bipolar plate according to any of claims 2 to 4, wherein said intermediate section (31) further comprises at least one uniform flow channel (312) passing between each of said intermediate flow channels (311).

6. A flow field structure of a fuel cell bipolar plate according to claim 5, wherein the uniform flow channels (312) are arranged obliquely and have a higher end toward the gas inlet (1) than an end toward the gas outlet (2).

7. The flow field structure of a fuel cell bipolar plate according to any one of claims 1 to 4, wherein the depth of the intermediate flow channels (311) is 0.4mm to 1.0 mm;

and/or the width of the middle flow channel (311) is 0.6 mm-2.0 mm;

and/or the distance between two adjacent intermediate flow passages (311) is 0.3 mm-2.0 mm.

8. A fuel cell bipolar plate comprising two plates, at least one of which is provided with a flow field structure of a fuel cell bipolar plate as claimed in any one of claims 1 to 7, and one of which forms an anode plate and the other forms a cathode plate.

9. A fuel cell bipolar plate as claimed in claim 8, wherein the ratio of the area of the channels (3) of the flow field structure to the area of the side of the plate on which the channels (3) are provided is 50-75%.

10. A fuel cell comprising the fuel cell bipolar plate according to claim 8 or 9.

Technical Field

The invention relates to the technical field of fuel cells, in particular to a fuel cell, a fuel cell bipolar plate and a flow field structure of the fuel cell bipolar plate.

Background

The design of the flow field structure is an effective way for improving the performance of the fuel cell, and the good design of the flow field structure can ensure that the gas fuel achieves better transfer efficiency in the cell, simultaneously can improve the discharge effect of liquid water of a reaction product, and prolongs the mass transfer limit, thereby improving the performance of the cell.

The flow channel structure of the present fuel cell bipolar plate mainly comprises a snake-shaped flow channel, a straight flow channel, a reticular flow channel and the like, wherein the snake-shaped flow channel is the most studied flow channel form and can rapidly remove liquid water generated by the reaction of the fuel cell, but for the bipolar plate with a larger area, the phenomena of overlarge pressure drop and uneven gas distribution caused by overlong flow channel exist; the straight channel flow passage can reduce the pressure drop of gas so as to improve the flow efficiency, but the reaction efficiency is lower due to the fact that the flow speed of the reaction gas in the straight channel flow passage is too high; the net-shaped flow field has flexible design and simple structure, but the gas flow velocity in the flow field is lower, the resistance drop is larger, and the water drainage capability is also poorer.

And the included angle between the gas inlet and the gas outlet of the reaction gas and the flow channel is always vertically arranged, so that the reaction gas can have lower gas flow velocity and larger resistance drop due to the arrangement of right angles when entering the flow channel.

How to simplify the flow field structure of the fuel cell bipolar plate, increase the gas flow rate and reduce the resistance drop to ensure the drainage performance is a technical problem that needs to be solved urgently by the technicians in the field.

Disclosure of Invention

The invention aims to provide a fuel cell, a fuel cell bipolar plate and a flow field structure of the fuel cell bipolar plate, which can simplify the flow field structure, improve the gas flow velocity, reduce the resistance drop and ensure the drainage performance.

In order to solve the technical problem, the invention provides a flow field structure of a fuel cell bipolar plate, which comprises an air inlet, a channel and an air outlet which are sequentially communicated, wherein the air inlet and the air outlet are respectively provided with an end flow passage; the channel comprises a middle section and two distribution sections arranged at two ends of the middle section respectively, the middle section comprises a plurality of middle runners which are in a wave-shaped structure and arranged in parallel, the distribution sections comprise a plurality of distribution runners, and the distribution runners are correspondingly communicated between the end runners and the middle runners; the distribution flow channel and the middle flow channel are communicated with each other, and an included angle between the distribution flow channel and the middle flow channel is an obtuse angle.

Locate the flow field structure of polar plate including the air inlet that communicates the setting in proper order, passageway and gas outlet, wherein, air inlet and gas outlet are equipped with the tip runner respectively, the passageway includes interlude and two distribution sections of locating this interlude both ends respectively, the interlude includes many parallel intermediate flow ways that set up side by side, the distribution section includes many distribution flow ways, each distribution flow way corresponds and communicates between tip runner and intermediate flow way, wherein, each intermediate flow way is wave structure and parallel arrangement, be equivalent to with one be wave structure's intermediate flow way in proper order according to predetermineeing the interval distance translation and arrange side by side and form one row at the surface of polar plate and have many intermediate flow ways that set up side by side, the crest position of each intermediate flow way corresponds, the trough position also corresponds. Specifically, a plurality of protrusions in a wave-shaped structure are arranged on the surface of the polar plate, the protrusions are arranged in parallel, and a middle flow channel is formed between every two adjacent protrusions.

Specifically, the reaction gas can diffuse into the membrane electrode in the flowing process to contact with the catalyst, generate chemical reaction and release current, and finally the residual reaction gas and a reaction product (liquid water) in the middle flow passage are discharged through the gas outlet. The middle flow channel arranged in the wave-shaped structure can prolong the flow distance of the air flow, and the effective area of the middle flow channel is increased, so that the reaction gas in the middle flow channel is more fully reacted, the reaction efficiency is improved, the flow resistance generated by the reaction gas can be reduced through the wave-shaped middle flow channel, the reaction gas can be conveniently brought out of liquid water when flowing out, and the drainage effect is favorably realized.

The included angle between the distribution flow channel and the middle flow channel which are communicated with each other is an obtuse angle, so that the air flow resistance can be reduced in the flowing process of the air, and the drainage effect is convenient to realize.

Optionally, the height of the air inlet is higher than the height of the air outlet.

Optionally, two of the distribution sections are symmetrically disposed about a central location of the intermediate section; the end flow channel arranged on the air inlet and the end flow channel arranged on the air outlet are symmetrically arranged around the center position of the middle section.

Optionally, each of the distribution flow channels is disposed obliquely, and an end portion of the distribution flow channel on one side facing the air inlet is higher than an end portion of the distribution flow channel on one side facing the air outlet.

Optionally, the intermediate section further comprises at least one uniform flow channel extending between each of the intermediate flow channels.

Optionally, the uniform flow channel is obliquely arranged, and an end portion of one side facing the air inlet is higher than an end portion of one side facing the air outlet.

Optionally, the depth of the intermediate flow channel is 0.4mm to 1.0 mm;

and/or the width of the middle runner is 0.6 mm-2.0 mm;

and/or the distance between two adjacent intermediate flow channels is 0.3 mm-2.0 mm.

The invention also provides a fuel cell bipolar plate which comprises two polar plates, at least one of the two polar plates is provided with the flow field structure of the fuel cell bipolar plate, and one of the two polar plates forms an anode plate, and the other polar plate forms a cathode plate.

Optionally, the ratio of the area of the channel of the flow field structure to the area of the side surface of the plate where the channel is located is 50% to 75%.

The invention also provides a fuel cell comprising the fuel cell bipolar plate as described above.

The fuel cell bipolar plate with the flow field structure and the fuel cell with the fuel cell bipolar plate have the technical effects similar to the technical effects of the flow field structure of the fuel cell bipolar plate, and are not repeated herein for saving space.

Drawings

FIG. 1 is a schematic structural view of a flow field structure of a bipolar plate for a fuel cell according to an embodiment of the present invention;

fig. 2 is a performance test chart of the fuel cell provided in the present embodiment and the fuel cell in the related art.

In FIGS. 1-2, the reference numbers are illustrated as follows:

1-an air inlet;

2-air outlet;

3-channel, 31-middle section, 311-middle flow channel, 312-uniform flow channel, 32-distribution section, 321-distribution flow channel;

4-end flow channel.

Detailed Description

In order to make the technical solutions of the present invention better understood by those skilled in the art, the present invention will be further described in detail with reference to the accompanying drawings and specific embodiments.

Referring to fig. 1-2, fig. 1 is a schematic structural diagram of a flow field structure of a bipolar plate of a fuel cell according to an embodiment of the present invention; fig. 2 is a performance test chart of the fuel cell provided in the present embodiment and the fuel cell in the related art.

The embodiment of the invention provides a fuel cell, a fuel cell bipolar plate and a flow field structure of the fuel cell bipolar plate, wherein the fuel cell refers to the fuel cell with the fuel cell bipolar plate, the fuel cell bipolar plate comprises two polar plates, at least one of the two polar plates is provided with the flow field structure of the fuel cell bipolar plate, and one of the two polar plates forms an anode plate, and the other forms a cathode plate.

Specifically, as shown in fig. 1, the flow field structure disposed on the plate comprises an air inlet 1, a channel 3 and an air outlet 2 which are sequentially communicated, wherein, the air inlet 1 and the air outlet 2 are respectively provided with an end flow passage 4, the channel 3 comprises a middle section 31 and two distribution sections 32 respectively arranged at two ends of the middle section 31, the middle section 31 comprises a plurality of middle flow passages 311 arranged in parallel, the distribution sections 32 comprise a plurality of distribution flow passages 321, each distribution flow passage 321 is correspondingly communicated between the end flow passage 4 and the middle flow passage 311, each of the middle runners 311 is in a wave-shaped structure and is arranged in parallel, which is equivalent to that one of the middle runners 311 in the wave-shaped structure is arranged in parallel in a manner of translating in sequence according to a preset interval distance and a row of the middle runners 311 arranged in parallel is formed on the surface of the plate, the peak positions of the middle runners 311 correspond to the valley positions of the middle runners 311. Specifically, a plurality of protrusions in a wave-shaped structure may be arranged on the surface of the plate, each protrusion is arranged in parallel, and a middle flow channel 311 is formed between two adjacent protrusions.

Specifically, the reaction gas can enter from the gas inlet 1 and enter the middle flow channel 311 of the middle section 31 along the distribution flow channel 321, and then enter the gas outlet 2 from the distribution flow channel 321 at the other end of the middle flow channel 311 to be discharged, specifically, the reaction gas can diffuse into the membrane electrode in the flowing process to contact with the catalyst, so as to undergo a chemical reaction and release current, and finally, the remaining reaction gas and the reaction product (liquid water) located in the middle flow channel 311 are discharged through the gas outlet 2. The middle flow channel 311 arranged in a wavy structure can prolong the flow distance of the air flow and improve the effective area of the middle flow channel 311, so that the reaction gas in the middle flow channel 311 is reacted more fully, which is beneficial to improving the reaction efficiency, and the wavy middle flow channel 311 enables the reaction gas to reduce the flow resistance generated by the reaction gas when passing through, so that the reaction gas can bring out liquid water when flowing out, and the effect of draining is beneficial to being realized.

The included angle between the distribution flow channel 321 and the middle flow channel 311 which are communicated with each other is an obtuse angle, so that the air flow resistance can be reduced in the flowing process of the air, and the drainage effect is convenient to realize.

In addition, in this embodiment, the specific structure of the end runners 4 is not limited, as shown in fig. 1, the number of the distribution runners 321 is greater than the number of the end runners 4, and the number of the distribution runners 321 is not greater than the number of the middle runners 311, that is, each end runner 4 corresponds to one group of distribution runners 321, and each distribution runner 321 is correspondingly communicated with one middle runner 311, so that the gas enters each end runner 4 from the gas inlet 1, and then enters the middle runners 311 after being dispersed in more distribution runners 321 and along the distribution runners 321, and in this process, the air resistance is small through the corner with the obtuse angle included, and the distribution runners 321 can enable the reaction gas entering from the gas inlet 1 to uniformly enter each middle runner 311. In addition, due to the arrangement of the distribution flow passage 321, the gas flow can be ensured to be stable when entering the middle flow passage 311 along the distribution flow passage 321, so that the arrangement of the end flow passage 4 is more flexible.

Specifically, in this embodiment, the flow field structure may be provided on the cathode plate, the flow field structure may be provided on the anode plate, or the flow field structures may be provided on the cathode plate and the anode plate, respectively.

In the above embodiment, the height of the gas inlet 1 is higher than that of the gas outlet 2, that is, in the use state, the reaction gas enters from the end flow channel 4 with the higher height and flows out from the end flow channel 4 with the lower height, so that the gas flow disturbance to the reaction gas can be reduced, and the flow resistance to the reaction gas can be reduced. As shown in fig. 1, the gas inlet 1 in this embodiment is disposed on the top of one end of the plate, and the gas outlet 2 is disposed on the bottom of the other end of the plate, that is, the gas inlet 1 and the gas outlet 2 are respectively located at opposite corners of the plate, so as to ensure that the gravity can provide power rather than resistance to the flow of the reactant gas, thereby further reducing the resistance to the gas flow.

Further, two distribution sections 32 at both ends of the intermediate section 31 are symmetrically disposed about the center position of the intermediate section 31, and at the same time, the end flow passage 4 provided at the air inlet 1 and the end flow passage 4 provided at the air outlet 2 are symmetrically disposed about the center position of the intermediate section 31. With the arrangement, the lengths of the intermediate flow passages 311 are the same, the flowing conditions of the reaction gases passing through the intermediate flow passages 311 are uniform, the difference between the reaction gases passing through the intermediate flow passages 311 is reduced, and the performance and the service life of the fuel cell are ensured.

In the above embodiment, each of the distribution flow channels 321 is disposed obliquely and in parallel, and the height of one side end of each of the distribution flow channels 321 facing the gas inlet 1 is higher than that of one side end facing the gas outlet 2, and the reactant gas can flow downward along the obliquely disposed distribution flow channel 321 under the action of gravity during the process that the reactant gas flows from the end flow channel 4 disposed at the gas inlet 1 to the intermediate flow channel 311 through the distribution flow channel 321 and during the process that the reactant gas flows from the intermediate flow channel 311 to the end flow channel 4 disposed at the gas outlet 2 through the distribution flow channel 321, so that the gravity action can provide power rather than resistance to the flow of the reactant gas, and further reduce the resistance and disturbance to the reactant gas caused when the reactant gas passes through the distribution flow channel 321.

In the above embodiment, the intermediate section 31 further includes at least one uniform flow channel 312 penetrating between the intermediate flow channels 311, and the uniform flow channel 312 is communicated with the intermediate flow channels 311, so as to balance the gas flow between the intermediate flow channels 311, ensure the uniformity of distribution of the reactant gas in the intermediate flow channels 311, and simultaneously, quickly discharge the liquid water, which is the reaction product in each intermediate flow channel 311, to prevent the individual flow channels from being blocked and flooded, and improve the performance and the service life of the fuel cell.

Specifically, in the present embodiment, the number of the uniform flow channels 312 is not limited, as shown in fig. 1, the middle section 31 in the present embodiment is provided with three uniform flow channels 312, and of course, only one uniform flow channel 312 may be provided, or two, four, or more uniform flow channels may be provided, and the number of the uniform flow channels 312 may be specifically set according to the length, the width, and the like of each middle flow channel 311.

In the above embodiment, the uniform flow passage 312 is obliquely arranged such that the end portion of the side facing the gas inlet 1 is higher than the end portion of the side facing the gas outlet 2, since the height of the gas inlet 1 is higher than that of the gas outlet 2, when the gas flow in each intermediate flow passage 311 is unevenly distributed, the gas flow in the intermediate flow passage 311 located at a high position is likely to be large (the height of the gas inlet 1 is high), that is, when the flow rate of the gas in the high middle flow passage 311 is relatively large and the uniform flow passage 312 is inclined and is high toward the one end of the intake port 1, part of the reaction gas in the middle passage 3 with a large gas flow rate flows along the uniform flow path 312 to the middle passage 3 with a small gas flow rate, since the included angle between the middle flow passage 311 and the uniform flow passage 312 is an obtuse angle, the resistance of the reaction gas in the middle flow passage 311 at a high position when flowing along the uniform flow passage 312 to the middle flow passage 311 at a low position can be reduced.

Moreover, because the middle flow passage 311 is arranged in a wave-shaped structure, the liquid water in the middle flow passage 311 at the high position flows to the middle flow passage 311 at the low position along the uniform flow passage 312, so that the situation that the liquid water is accumulated at the wave trough of the middle flow passage 311 to cause blockage due to large air flow at the high position can be avoided.

In the above embodiment, the size specification of the intermediate flow passage 311 is not limited, and specifically, the size of the intermediate flow passage 311 is set to satisfy at least one of the following: the depth of the middle flow channel 311 is 0.4 mm-1.0 mm, the width of the middle flow channel 311 is 0.6 mm-2.0 mm, and the distance between two adjacent middle flow channels 311 is 0.3 mm-2.0 mm (namely the width of the bulge arranged on the polar plate is 0.3 mm-2.0 mm). By the arrangement, the processing technology can be simplified while the large effective area is ensured.

And the ratio of the area of the channel 3 of the flow field structure arranged on the polar plate to the area of one side surface of the polar plate provided with the channel 3 is 50-75%, so that the polar plate has enough utilization rate and the processing technology requirement on the flow field structure is reduced.

The performance of the fuel cell provided in this embodiment and the fuel cell in the prior art is tested, and the result is shown in fig. 2, where the fuel cell in the prior art refers to a fuel cell having a serpentine flow channel, and it can be seen that, under the condition of the same current density, the voltage of the fuel cell having the flow field structure provided in this embodiment is higher than that of the fuel cell having a common flow field, and the power of the fuel cell is higher and the performance advantage is more obvious.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that it is obvious to those skilled in the art that various modifications and improvements can be made without departing from the principle of the present invention, and these modifications and improvements should also be considered as the protection scope of the present invention.