CN210576223U

CN210576223U - Bipolar plate, fuel cell stack comprising same and power generation system

Info

Publication number: CN210576223U
Application number: CN201921507707.6U
Authority: CN
Inventors: 张国胜; 张知劲
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-05-16
Filing date: 2019-09-10
Publication date: 2020-05-19
Anticipated expiration: 2029-09-10

Abstract

A bipolar plate and fuel cell pile and generating system containing the bipolar plate, the bipolar plate includes the first polar plate and the second polar plate, the first polar plate has the first and the second face, the second polar plate has the third and the fourth face, the first face of the first polar plate has the first flow channel and the first reference surface; a third surface of the second polar plate is provided with a third flow channel and a third reference surface; the second surface of the first polar plate and the fourth surface of the second polar plate are jointed together in the bipolar plate; the first face of the first plate and the third face of the second plate have different flow fields. It also includes at least two simultaneous undulating zones which are channels for the introduction and removal of coolant into and out of the bipolar plate sandwich. And a coolant guide dike is arranged on the second polar plate and can guide the coolant to flow according to a set route. The bipolar plate has the advantages of good drainage, good cooling effect and the like due to the characteristics.

Description

Bipolar plate, fuel cell stack comprising same and power generation system

Technical Field

The utility model belongs to the technical field of fuel cell, in particular to used bipolar plate and contain this bipolar plate's fuel cell pile and power generation system in the fuel cell pile.

Background

The fuel cell is an electrochemical reaction device capable of converting chemical energy into electric energy, has the advantages of high energy conversion efficiency, zero emission, no mechanical noise and the like, and is favored in the fields of military affairs and civil use. Proton Exchange Membrane Fuel Cells (PEMFC) adopt a solid polymer membrane as an electrolyte, have the advantages of simple structure, low working temperature and the like, and have the advantage of being unique as a mobile power supply. International well-known automobiles such as japan toyota automobiles and korean modern automobiles have developed mass-produced fuel cell electric vehicles (FCEV or FCV) powered by PEMFC.

Each PEMFC cell is composed of two plates (an anode plate and a cathode plate) and a membrane electrode sandwiched between the two plates. The anode plate of the PEMFC is provided with a fuel flow channel, which is a place where fuel flows and is transported, through which the fuel is transported to the anode catalyst. The cathode plate of the PEMFC is provided with an oxidant flow channel, which is a place where an oxidant (oxygen or air) flows and is transferred, through which the oxidant reaches the cathode catalyst. By means of the fuel flow passage and the oxidant flow passage, the fuel and the oxidant can be supplied into the fuel cell continuously so that the fuel cell can output electric power continuously.

In order to increase the total generated power of the Fuel Cell, a plurality of single cells are generally connected in series to form a Fuel Cell Stack (Fuel Cell Stack). In a fuel cell stack, except for the outermost two unit cells, an anode plate of any unit cell in the stack is closely attached to a cathode plate of an adjacent unit cell. The structure of the fuel cell stack can be simplified and the reliability of the operation of the fuel cell stack can be improved by fixedly coupling the anode plate and the cathode plate, which are closely attached, to form a single member called a bipolar plate (bipolar plate).

The bipolar plate is one of the key components in a fuel cell stack, in which various functions such as supporting a membrane electrode assembly, distributing reaction gas, transmitting current, conducting heat, and discharging water, which is a reaction product, are performed. Under the existing technical condition, the manufacturing cost of the bipolar plate accounts for 40-50% of the total manufacturing cost of the whole fuel cell stack.

The fuel flow channels and oxidant flow channels on the bipolar plates are of various types, and straight-through flow channels and a plurality of parallel serpentine flow channels are adopted at present. The straight-through flow channel has simple structure and small flow resistance, but the power generation power of the fuel cell stack is sensitive to the fluctuation of gas pressure. The pressure drop of the plurality of parallel serpentine channels is large, which facilitates the diffusion of gas to the gas diffusion layer and the electrode catalyst, but the serpentine channels are not favorable for discharging the water of the reaction product if the serpentine channels are adopted on the cathode side of the PEMFC. In the prior art, the fuel flow channel on the anode plate and the oxidant flow channel on the cathode plate are always in the same form, namely, both the fuel flow channel and the oxidant flow channel are serpentine flow channels or both straight flow channels, and in this case, it is difficult to simultaneously adjust the pressure drop of hydrogen and the pressure drop of air (or oxygen) to the optimal values.

In the previous research work, the cathode plate and the anode plate of the bipolar plate are both designed into the serpentine flow field plate, and the cathode plate and the anode plate of the bipolar plate have the same shape (see the disclosure of the chinese utility model patent with the application number of 201810373488.0 and the U.S. patent with the application number of 16/231950), so that a set of stamping die can be saved, and the manufacturing cost of the bipolar plate can be reduced. However, the bipolar plate has poor water drainage because the fluidity of air is lower than that of hydrogen.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a bipolar plate, its anode plate and negative plate have different flow fields to can all adjust the pressure drop of the hydrogen pressure drop of PEMFC positive pole one side and the pressure drop of the air (or oxygen) of PEMFC negative pole one side to the optimum simultaneously, can also make PEMFC negative pole one side have good drainage.

Another object of the utility model is to provide a fuel cell pile and power generation system who contains above-mentioned bipolar plate has a great deal of advantages such as the generating efficiency is high, the drainage is good, easy temperature control, and application prospect is extensive.

In order to achieve the purpose, the utility model adopts the following technical proposal:

a bipolar plate comprising a first plate having a first face and a second plate having a third face and a fourth face, the first face of the first plate having a first flow channel and a first reference face thereon, the third face of the second plate having a third flow channel and a third reference face thereon, the first flow channel being a groove formed in a thickness direction with respect to the first reference face, the third flow channel being a groove formed in the thickness direction with respect to the third reference face; the second surface of the first polar plate is provided with a second flow passage and a second reference surface, the fourth surface of the second polar plate is provided with a fourth flow passage and a fourth reference surface, the second flow passage is a groove formed in the thickness direction relative to the second reference surface, and the fourth flow passage is a groove formed in the thickness direction relative to the fourth reference surface; the thickness direction is parallel to the stacking direction of the bipolar plate in the fuel cell stack; the second surface of the first polar plate and the fourth surface of the second polar plate are jointed together in the bipolar plate; the first flow channel on the first surface of the first polar plate comprises a U-shaped section, and the third flow channel on the third surface of the second polar plate does not comprise a U-shaped section; the U-shaped section comprises a first section, a second section and a third section, an included angle formed by the flowing direction of fluid in the first section and the flowing direction in the third section in the fuel cell stack is positioned in a range of [150 degrees and 180 degrees ], an included angle formed by the flowing direction in the first section and the flowing direction in the second section is positioned in a range of [60 degrees and 120 degrees ], and an included angle formed by the flowing direction in the second section and the flowing direction in the third section is positioned in a range of [60 degrees and 120 degrees ];

the bipolar plate comprises a synchronous undulating region, wherein the synchronous undulating region is an area on the bipolar plate, the synchronous undulating region comprises a second flow channel, a second reference surface, a fourth flow channel and a part of a fourth reference surface, and the second reference surface is not in contact with the fourth reference surface.

Further, a coolant flow dike is arranged on the second electrode plate, and the coolant flow dike is a fourth reference surface formed by blocking a part of the fourth flow channel.

Furthermore, two opposite corners of the different sides of the bipolar plate are respectively provided with a coolant inlet and a coolant outlet which are respectively communicated with coolant flow channels corresponding to two synchronous undulating regions positioned at the opposite corners.

Furthermore, a coolant inlet and a coolant outlet are respectively formed in adjacent inner corners of the bipolar plate on the same side and are respectively communicated with coolant flow channels corresponding to the two synchronous undulating regions located in the adjacent inner corners on the same side.

Furthermore, a plurality of upper supporting platforms or lower supporting platforms are arranged in the synchronous fluctuation area; the upper support table is a second reference surface formed by blocking a part of the second flow passage, and the lower support table is a fourth reference surface formed by blocking a part of the fourth flow passage.

Furthermore, the first polar plate and the second polar plate are made and molded by a metal or alloy sheet with the thickness of less than 0.5mm through a pressure processing method.

Further, the second flow passage in the synchronous undulating region is a transverse section of the second flow passage; the transverse section is parallel to a second section of the U-shaped sections in the first flow channel;

the bipolar plate comprises at least two synchronous undulating regions;

the bipolar plate includes coolant inlet channels that communicate with one of the lands and coolant outlet channels that communicate with the other land.

Further, the bipolar plate comprises a cross flow region and a parallel flow region, and the projected area of the cross flow region in the reference plane is larger than the projected area of the parallel flow region in the reference plane; the reference plane is a plane perpendicular to the thickness direction and is a virtual plane;

the cross flow area refers to an area on the bipolar plate, and an included angle formed by the flow direction of fluid in a first flow channel in the cross flow area and the flow direction of fluid in a third flow channel in the cross flow area in the fuel cell stack is positioned in an interval of [60 degrees and 120 degrees ];

the parallel flow area refers to an area on the bipolar plate, and an included angle formed by the flow direction of fluid in a first flow channel in the parallel flow area and the flow direction of fluid in a third flow channel in the parallel flow area in the fuel cell stack is positioned in a [0 degrees, 30 degrees ] area or a [150 degrees, 180 degrees ] area;

the simultaneous undulating zones on the bipolar plate are located in or overlap the parallel flow zones.

Further, two or more coolant guide dikes are arranged on the second polar plate, so that the flow route of the coolant in the space between the first polar plate and the second polar plate under the guidance of the coolant guide dikes is S-shaped or serpentine.

A bipolar plate comprising a first plate having a first face and a second plate having a third face and a fourth face, the first face of the first plate having a first flow channel and a first reference face thereon, the third face of the second plate having a third flow channel and a third reference face thereon, the first flow channel being a groove formed in a thickness direction with respect to the first reference face, the third flow channel being a groove formed in the thickness direction with respect to the third reference face; the second surface of the first polar plate is provided with a second flow passage and a second reference surface, the fourth surface of the second polar plate is provided with a fourth flow passage and a fourth reference surface, the second flow passage is a groove formed in the thickness direction relative to the second reference surface, and the fourth flow passage is a groove formed in the thickness direction relative to the fourth reference surface; the thickness direction is parallel to the stacking direction of the bipolar plate in the fuel cell stack; the second surface of the first polar plate and the fourth surface of the second polar plate are jointed together in the bipolar plate; the first flow channel on the first surface of the first polar plate comprises an S-shaped section, and the third flow channel on the third surface of the second polar plate does not comprise an S-shaped section; the S-shaped section comprises a fourth section, a fifth section and a sixth section, the length of the fifth section is more than 3 times the width of the sixth section, in the fuel cell stack, the fluid flows through the fourth section, the fifth section and the sixth section in sequence, the included angle formed by the flow direction in the fourth section and the flow direction in the sixth section is in the interval of [0 degrees and 30 degrees ], the included angle formed by the flow direction in the fourth section and the flow direction in the fifth section is in the interval of [60 degrees and 120 degrees ], and the included angle formed by the flow direction in the fifth section and the flow direction in the sixth section is in the interval of [60 degrees and 120 degrees ];

the bipolar plate comprises a synchronous undulating region; the synchronous undulating region refers to a region on the bipolar plate, wherein the synchronous undulating region comprises a second flow channel, a second reference surface, a fourth flow channel and a part of a fourth reference surface, and the second reference surface and the fourth reference surface are not in contact.

Further, the second flow passage in the synchronous undulating region is a transverse section of the second flow passage; the transverse segment is parallel to a fifth segment of the S-shaped segments in the first flow channel;

the bipolar plate comprises at least two of said synchronized undulating regions, one synchronized undulating region communicating with the coolant inlet channels and the other synchronized undulating region communicating with the coolant outlet channels.

A fuel cell stack comprises the bipolar plate.

A fuel cell power generation system comprises the fuel cell stack.

The utility model has the advantages that:

(1) when the bipolar plate of the utility model is arranged in the proton exchange membrane fuel cell stack, the flow channel (usually a snake-shaped flow channel) with a U-shaped section or the flow channel with an S-shaped section is arranged at one side of the anode, so that hydrogen with better fluidity than air and oxygen needs to turn for many times in the flowing process to generate larger pressure drop, thereby being beneficial to the diffusion of the hydrogen to a gas diffusion layer and a catalyst; the flow channel (straight-through flow channel) having no U-shaped section or S-shaped section is provided on the cathode side, so that air or oxygen having poor fluidity than hydrogen does not need to turn during the flow, which not only can obtain a suitable pressure drop but also is advantageous for discharging water as a reaction product.

(2) The utility model discloses a set up synchronous undulant district and can make the coolant flow under the prerequisite that does not increase the thickness of bipolar plate and go through whole reaction zone, be convenient for control the temperature of fuel cell pile.

(3) The utility model discloses a set up the flow path that coolant water conservancy diversion dyke can control the coolant, can eliminate coolant runner dead angle, can control coolant flow rate again to reduce the produced parasitic power of coolant pump.

(4) The utility model discloses the vertical plate muscle that forms the third runner on the horizontal plate muscle that forms first runner on the first polar plate and the second polar plate can alternately exert pressure to membrane electrode to reduce fuel cell's internal resistance.

Drawings

Fig. 1A is a schematic structural view of a first surface of a first plate of embodiment 1 of a bipolar plate according to the present invention.

Fig. 1B is a schematic structural view of the second surface of the first plate of embodiment 1 of the bipolar plate of the present invention.

Fig. 2A is a schematic structural view of a third surface of a second plate in embodiment 1 of the bipolar plate of the present invention.

Fig. 2B is a schematic structural view of a fourth surface of a second plate of embodiment 1 of the bipolar plate of the present invention.

Fig. 3 is a schematic view of the assembly state of embodiment 1 of the bipolar plate of the present invention.

Fig. 4 is a schematic structural view of a fourth surface of a second bipolar plate according to embodiment 2 of the present invention.

Fig. 5 is a schematic view showing the assembly state of embodiment 2 of the bipolar plate of the present invention.

FIG. 6A is a cross-sectional view taken in the direction A1-A1 of FIG. 3.

FIG. 6B is a sectional view taken in the direction A11-A11 in FIG. 5.

FIG. 7A is a cross-sectional view taken in the direction A2-A2 of FIG. 3.

FIG. 7B is a sectional view taken in the direction A21-A21 in FIG. 5.

Fig. 7C is an enlarged schematic view at D in fig. 7B.

FIG. 8 is a sectional view taken in the direction B1-B1 in FIG. 5.

FIG. 9 is a sectional view taken in the direction B2-B2 in FIG. 5.

Figure 10 is a schematic view of the coolant flow direction of bipolar plate embodiment 2 of the present invention.

Fig. 11A is a schematic structural view of the first surface of the first plate of embodiment 3 of the bipolar plate of the present invention.

Fig. 11B is a schematic structural view of the second surface of the first plate of embodiment 3 of the bipolar plate of the present invention.

Fig. 12 is a schematic structural view of a fourth surface of a second plate of embodiment 3 of the bipolar plate of the present invention.

Fig. 13 is a schematic view showing the assembled state of embodiment 3 of the bipolar plate of the present invention.

Figure 14A is a schematic view of the first side of a first plate of embodiment 4 of a bipolar plate according to the present invention.

Figure 14B is a schematic diagram of the second side of the first plate of embodiment 4 of the bipolar plate of the present invention.

Fig. 15 is a schematic view showing the assembled state of embodiment 4 of the bipolar plate of the present invention.

Fig. 16 is a schematic view showing the assembled state of embodiment 5 of the bipolar plate of the present invention.

FIG. 17A is a cross-sectional view taken in the direction A3-A3 of FIG. 15.

FIG. 17B is a sectional view taken in the direction A31-A31 of FIG. 16.

FIG. 18A is a cross-sectional view taken in the direction A4-A4 of FIG. 15.

FIG. 18B is a sectional view taken in the direction A41-A41 of FIG. 16.

Fig. 18C is an enlarged schematic view at E in fig. 18B.

FIG. 19 is a sectional view taken in the direction B3-B3 of FIG. 16.

FIG. 20 is a sectional view taken in the direction B4-B4 of FIG. 16.

Detailed Description

The present invention is further described with reference to the following drawings and specific embodiments so that those skilled in the art can better understand the present invention and can implement the present invention, but the embodiments are not to be construed as limiting the present invention.

The utility model provides a bipolar plate, the first face of its first polar plate and the third face of second polar plate have different flow fields, make the flow direction of fuel (hydrogen) take place quartic change at least in the fuel runner, and the oxidant flow direction in the oxidant runner is through type, and is unchangeable for air or oxygen that mobility is poor than hydrogen need not the turn at the flow in-process, can obtain suitable pressure drop like this and be favorable to the discharge of reaction product water again.

As shown in fig. 1A to 3, the present invention provides a bipolar plate, which is the embodiment 1 of the present invention, including a first plate 1 and a second plate 2, the first plate 1 has a first surface 11 and a second surface 12, the second plate 2 has a third surface 21 and a fourth surface 22, the second surface 12 of the first plate 1 and the fourth surface 22 of the second plate 2 are attached together, and a coolant flow channel 3 is formed therebetween. The first plate 1 has a first flow channel 111 and a first reference surface 112 on the first surface 11, and a second flow channel 121 and a second reference surface 122 on the second surface 12. The second plate 2 has a third flow channel 211 and a third reference surface 212 on a third surface 21, and a fourth flow channel 221 and a fourth reference surface 222 on a fourth surface 22. The first flow channel 111 is a groove formed in the thickness direction with respect to the first reference surface 112, the second flow channel 121 is a groove formed in the thickness direction with respect to the second reference surface 122, the third flow channel 211 is a groove formed in the thickness direction with respect to the third reference surface 212, and the fourth flow channel 221 is a groove formed in the thickness direction with respect to the fourth reference surface 222. The thickness direction is parallel to a stacking direction of the bipolar plates when the bipolar plates are disposed in a fuel cell stack. The first flow channel 111 includes a U-shaped section 4, and the third flow channel does not include a U-shaped section, and is a plurality of parallel straight-through flow channels or a plurality of parallel small-amplitude oscillating wave-shaped flow channels. The U-shaped section 4 comprises a first section 41, a second section 42, and a third section 43 connected in series. The flow directions of the fluid participating in the electrochemical reaction or the product of the electrochemical reaction in the first, second, and

third sections

41, 42, and 43 are a first direction, a second direction, and a third direction, respectively, which are opposite to each other, and are perpendicular to each other, and the second direction and the third direction are perpendicular to each other. The angles between the first direction, the second direction and the third direction are preferred, but not limited thereto. For example, the first direction and the third direction form an angle in the interval [150 °,180 ° ], the first direction and the second direction form an angle in the interval [60 °,120 ° ], and the second direction and the third direction form an angle in the interval [60 °,120 ° ].

The second flow channel 121 (corresponding to the first flow channel relief) includes a transverse section H and a longitudinal section Z, the transverse section H being parallel to the second section 42 of the U-shaped section 4 in the first flow channel 111.

The bipolar plate of the present invention comprises at least two synchronous undulating regions for introducing and removing the coolant, which are located between the second face 12 and the fourth face 22 and correspond to the position of the transverse segment H (second segment 42). The synchronous undulating region refers to a specific region on the bipolar plate, in which the second flow channel 121, the second reference surface 122, the fourth flow channel 221 and the fourth reference surface 222 are included, in which the second reference surface 122 and the fourth reference surface 222 are not in contact, and the second flow channel 121 in the synchronous undulating region is the transverse section H thereof.

The bipolar plate also comprises a coolant inlet channel 5 and a coolant outlet channel 6 which are respectively positioned at two opposite corners of the opposite side of the bipolar plate, the coolant inlet channel 5 is communicated with the coolant flow channel in one synchronous undulating region, and the coolant outlet channel is communicated with the coolant flow channel in the other synchronous undulating region. The coolant flows from the coolant inlet passage 5 into one of the simultaneous undulating regions, then flows longitudinally along the second flow passage while flowing laterally along the fourth flow passage to flow throughout the entire reaction region, and then flows out from the other simultaneous undulating region into the coolant outlet passage 6. The direction of the arrows in fig. 3 indicates the flow path of the coolant.

As can be seen from fig. 3, the bipolar plate includes a cross flow region X and a parallel flow region Y, and the projected area of the cross flow region X in the reference plane is larger than the projected area of the parallel flow region Y in the reference plane; the reference plane is a plane perpendicular to the thickness direction and is a virtual plane; the cross flow region X refers to a region on the bipolar plate, and an included angle formed by a flow direction of a fluid in a first flow channel in the cross flow region and a flow direction of a fluid in a third flow channel in the cross flow region in the fuel cell stack is positioned in a range of [60 degrees and 120 degrees ] (preferably, the two directions are perpendicular); the parallel flow area Y refers to an area on the bipolar plate, and the included angle formed by the flow direction of the fluid in the first flow channel in the parallel flow area and the flow direction of the fluid in the third flow channel in the parallel flow area in the fuel cell stack is located in a [0 degrees, 30 degrees ] interval or a [150 degrees, 180 degrees ] (preferably, the two directions are the same or opposite); the simultaneous undulating region on the bipolar plate is located in or overlaps with the parallel flow region Y. In the synchronous fluctuation area, the second flow channel and the fourth flow channel are mutually staggered, the central lines of the projections of the second flow channel and the fourth flow channel in the reference plane are parallel and do not overlap, the second reference plane and the fourth reference plane are also staggered, and a connected coolant flow channel with a wavy cross section is formed, so that the coolant can flow into the second flow channel and the fourth flow channel.

As shown in fig. 1B, 6A, and 7A, in order to prevent deformation of the coolant flow passage 3 due to the pressing of the upper and lower bipolar plates in the synchronization fluctuation region, the horizontal section H has a plurality of upper support bases 44, and each of the upper support bases 44 blocks the second flow passage 121 and correspondingly penetrates the first flow passage on the back surface. A plurality of lower support stages may be provided at positions of the fourth flow channel corresponding to the horizontal sections H, and each lower support stage may block the fourth flow channel 221 to communicate with the third flow channel on the back surface. In practice, the upper support stage is a second reference surface formed by blocking a portion of the second flow passage, and the lower support stage is a fourth reference surface formed by blocking a portion of the fourth flow passage.

As shown in fig. 4-5, fig. 6B, fig. 7C, fig. 8-fig. 10, which are embodiments 2 of the bipolar plate of the present invention, two opposite corners of the bipolar plate are respectively provided with a coolant inlet 5 and a coolant outlet 6, which are respectively communicated with two simultaneous undulating regions located at opposite corners. The first electrode plate 1 of the present embodiment has the same structure as that of embodiment 1.

The second electrode plate 2 is provided with a coolant flow dike 7, and the coolant flow dike 7 is a fourth reference surface formed on the fourth surface 22 for blocking the fourth flow channel 221. The coolant guiding embankment 7 extends inwards from the outermost side of the fourth flow channel, is perpendicular to or close to perpendicular to the fourth flow channel 221, and the length of the coolant guiding embankment 7 is smaller than the total width of all the fourth flow channels 221. Preferably, a coolant guide dam 7 is provided inside the coolant inlet 5 and inside the coolant outlet 6, respectively, so that the coolant flows in an S-shaped or serpentine shape in the space between the first and second electrode plates. Of course, more coolant dams 7 may be provided. The arrow direction in fig. 10 indicates the flow path of the main flow of the coolant.

Also, as shown in fig. 6B and 7B, in order to prevent deformation due to the pressing of the upper and lower bipolar plates at the timing undulating region and block the coolant flow channel 3, the horizontal section H has a plurality of upper support stands 44. Of course, several lower support tables may be provided there.

As shown in fig. 11A-13, which is an embodiment 3 of the bipolar plate of the present invention, the difference between the embodiment 3 and the embodiment 2 is that the bipolar plate has a coolant inlet 5 and a coolant outlet 6 respectively disposed at adjacent inner corners on the same side, and the coolant inlet and the coolant outlet are respectively communicated with the coolant flow channels 3 corresponding to two synchronized undulating regions located at the adjacent inner corners on the same side. The structure of the first plate 1 of the present embodiment is shown in fig. 11A and 11B, and the structure of the second plate 2 of the present embodiment is shown in fig. 12.

The second electrode plate 2 is provided with a coolant flow dike 7, and the coolant flow dike 7 is a fourth reference plane of a strip shape formed on the fourth surface 22 for blocking the fourth flow channel 221, and is disposed between adjacent longitudinal sections Z corresponding to the second flow channel. The coolant guiding embankment 7 extends inwards from the outermost side of the fourth flow channel, is perpendicular to or close to perpendicular to the fourth flow channel 221, and the length of the coolant guiding embankment 7 is smaller than the total width of all the fourth flow channels 221. Preferably, a coolant guide dam 7 is provided inside the coolant inlet 5 and inside the coolant outlet 6, respectively, so that the coolant flows in an S-shaped or serpentine shape in the space between the first and second electrode plates. Of course, more coolant dams 7 may be provided. Fig. 13 is an assembly view of the first electrode plate and the second electrode plate, and the direction of arrows in the drawing indicates the flow route of the main flow of the coolant.

As shown in fig. 14A-15, which are embodiment 4 of the bipolar plate of the present invention, in this embodiment, the first flow channel 111 includes an S-shaped section 4', and the third flow channel does not include an S-shaped section, and is a plurality of parallel straight-through flow channels or a plurality of parallel small-amplitude oscillating wave-shaped flow channels. The S-shaped section 4 ' includes a fourth section 41 ', a fifth section 42 ', and a sixth section 43 ' and the length of the fifth section 42 ' is greater than 3 times the width of the sixth section 43 ', the fourth section 41 ', the fifth section 42 ', and the sixth section 43 ' are flowed through by the fluid in the fuel cell stack in this order, and the angle formed by the flow direction in the fourth section 41 ' and the flow direction in the sixth section 43 ' is located in the [0 °,30 ° ] interval (preferably 0 °), the angle formed by the flow direction in the fourth section 41 ' and the flow direction in the fifth section 42 ' is located in the [60 °,120 ° ] interval (preferably 90 °), and the angle formed by the flow direction in the fifth section 42 ' and the flow direction in the sixth section 43 ' is located in the [60 °,120 ° ] interval (preferably 90 °). The structure of the first plate is shown in fig. 14A, 14B, the structure of the second plate is the same as that of the second plate in embodiment 1, fig. 15 is an assembled view of the first plate and the second plate, and the flow route of the coolant is substantially the same as that of the coolant flow route shown in fig. 3.

The second flow channel 121 (corresponding to the first flow channel relief) includes a transverse section H and a longitudinal section Z, the transverse section H being parallel to the fifth section 42 'of the S-shaped section 4' in the first flow channel 111. The bipolar plate of this embodiment also includes at least two simultaneous undulating regions located between the second face 12 and the fourth face 22 and corresponding to the position of the transverse segment H (fifth segment 42'). In the synchronous undulating region, a second flow channel, a second reference surface, a fourth flow channel and a fourth reference surface are included and the second reference surface 122 and the fourth reference surface 222 do not contact. The second flow path 121 in the simultaneous undulating region is the transverse section H thereof.

The bipolar plate also comprises a coolant inlet channel 5 and a coolant outlet channel 6, which are respectively positioned at two opposite corners of the opposite sides of the bipolar plate, wherein the coolant inlet channel 5 is communicated with one of the synchronous undulating regions, and the coolant outlet channel 6 is communicated with the other synchronous undulating region. The coolant flows from the coolant inlet channel into one of the simultaneous undulating regions, then flows longitudinally along the second flow channel while flowing laterally along the fourth flow channel to flow throughout the reaction zone, and then flows out of the other simultaneous undulating region into the coolant outlet channel.

As can be seen from fig. 15, the bipolar plate includes a cross flow region X and a parallel flow region Y, and the projected area of the cross flow region X in the reference plane is larger than the projected area of the parallel flow region Y in the reference plane; the reference plane is a plane perpendicular to the thickness direction and is a virtual plane; the cross flow region X refers to a region on the bipolar plate, and an included angle formed by a flow direction of a fluid in a first flow channel in the cross flow region and a flow direction of a fluid in a third flow channel in the cross flow region in the fuel cell stack is positioned in a range of [60 degrees and 120 degrees ] (preferably, the two directions are perpendicular); the parallel flow area Y refers to an area on the bipolar plate, and the included angle formed by the flow direction of the fluid in the first flow channel in the parallel flow area and the flow direction of the fluid in the third flow channel in the parallel flow area in the fuel cell stack is located in a [0 degrees, 30 degrees ] interval or a [150 degrees, 180 degrees ] (preferably, the two directions are the same or opposite); the simultaneous undulating region on the bipolar plate is located in or overlaps with the parallel flow region Y. In the synchronous fluctuation area, the second flow channel and the fourth flow channel are mutually staggered, the central lines of the projections of the second flow channel and the fourth flow channel in the reference plane are parallel and do not overlap, the second reference plane and the fourth reference plane are also staggered, and a connected coolant flow channel with a wavy cross section is formed, so that the coolant can flow into the second flow channel and the fourth flow channel.

As shown in fig. 14B, 17A, and 18A, in order to prevent the fifth stage 42 ' from being deformed by the pressing of the upper and lower bipolar plates and block the coolant flow channel 3, the horizontal stage H has a plurality of upper support bases 44 ', each of which 44 ' blocks the second flow channel 121 and correspondingly penetrates the first flow channel on the back surface. A plurality of lower support stages may be provided at positions of the fourth flow channel corresponding to the horizontal sections H, and each lower support stage may block the fourth flow channel 221 to communicate with the third flow channel on the back surface. In practice, the upper support stage is a second reference surface formed by blocking a portion of the second flow passage, and the lower support stage is a fourth reference surface formed by blocking a portion of the fourth flow passage.

As shown in fig. 16, 17B, 18C, and 19 to 20, which are examples 5 of the bipolar plate of the present invention, the first plate has the same structure as example 4, as shown in fig. 14A and 14B, and the second plate has the same structure as the second plate in example 2, and a coolant embankment 7' is provided, as shown in fig. 4, and the flow path of the coolant is substantially the same as the coolant flow path shown in fig. 10.

From the viewpoint of geometric topology, the essential difference between the

embodiments

4 and 5 and the

embodiments

1 and 2 is that: in example 4 and example 5, neither the first flow channel on the first plate nor the third flow channel on the second plate includes a U-shaped section (or a "backflow section"); in

embodiments

1 and 2, the first flow channel of the first plate includes a U-shaped section (or "reflow section").

Preferably, the first electrode plate 1 and the second electrode plate 2 according to the embodiments of the present invention are formed by pressing a metal or alloy thin plate having a thickness of less than 0.5 mm. The bipolar plate of the embodiments of the present invention further comprises a conventional fuel inlet channel, a conventional fuel outlet channel, a conventional oxidant inlet channel, and a conventional oxidant outlet channel, which are through holes formed at the edge of the bipolar plate.

The utility model also provides a fuel cell pile, include bipolar plate. In addition, the utility model also provides a fuel cell power generation system, include the fuel cell pile.

The above embodiments are merely illustrative of the principles and effects of the present invention, and are not to be construed as limiting the invention. The present invention can be modified in many ways without departing from the spirit and scope of the present invention, and those skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which may be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.

Claims

1. A bipolar plate comprising a first plate having a first face and a second plate having a third face and a fourth face, the first face of the first plate having a first flow channel and a first reference face thereon, the third face of the second plate having a third flow channel and a third reference face thereon, the first flow channel being a groove formed in a thickness direction with respect to the first reference face, the third flow channel being a groove formed in the thickness direction with respect to the third reference face; the second surface of the first polar plate is provided with a second flow passage and a second reference surface, the fourth surface of the second polar plate is provided with a fourth flow passage and a fourth reference surface, the second flow passage is a groove formed in the thickness direction relative to the second reference surface, and the fourth flow passage is a groove formed in the thickness direction relative to the fourth reference surface; the thickness direction is parallel to the stacking direction of the bipolar plate in the fuel cell stack; the second surface of the first polar plate and the fourth surface of the second polar plate are jointed together in the bipolar plate; the first flow channel on the first surface of the first polar plate comprises a U-shaped section, and the third flow channel on the third surface of the second polar plate does not comprise a U-shaped section; the U-shaped section comprises a first section, a second section and a third section, an included angle formed by the flowing direction of fluid in the first section and the flowing direction in the third section in the fuel cell stack is positioned in a range of [150 degrees and 180 degrees ], an included angle formed by the flowing direction in the first section and the flowing direction in the second section is positioned in a range of [60 degrees and 120 degrees ], and an included angle formed by the flowing direction in the second section and the flowing direction in the third section is positioned in a range of [60 degrees and 120 degrees ];

2. The bipolar plate of claim 1, wherein a coolant dam is disposed on the second plate, the coolant dam being a fourth reference plane formed by blocking a portion of the fourth flow channels.

3. The bipolar plate as claimed in claim 1 or 2, wherein a coolant inlet and a coolant outlet are formed at two opposite corners of the opposite side of the bipolar plate, respectively, and are communicated with coolant channels corresponding to two simultaneous undulating regions located at the opposite corners, respectively.

4. The bipolar plate as claimed in claim 1 or 2, wherein the bipolar plate has a coolant inlet and a coolant outlet at adjacent inner corners on the same side, and the coolant inlets and the coolant outlets are respectively communicated with coolant channels corresponding to two simultaneous undulating regions at the adjacent inner corners on the same side.

5. A bipolar plate as in claim 1, wherein the second flow channels in said simultaneous undulating region are transverse segments of the second flow channels; the transverse section is parallel to a second section of the U-shaped sections in the first flow channel;

the bipolar plate comprises at least two synchronous undulating regions;

6. A bipolar plate comprising a first plate having a first face and a second plate having a third face and a fourth face, the first face of the first plate having a first flow channel and a first reference face thereon, the third face of the second plate having a third flow channel and a third reference face thereon, the first flow channel being a groove formed in a thickness direction with respect to the first reference face, the third flow channel being a groove formed in the thickness direction with respect to the third reference face; the second surface of the first polar plate is provided with a second flow passage and a second reference surface, the fourth surface of the second polar plate is provided with a fourth flow passage and a fourth reference surface, the second flow passage is a groove formed in the thickness direction relative to the second reference surface, and the fourth flow passage is a groove formed in the thickness direction relative to the fourth reference surface; the thickness direction is parallel to the stacking direction of the bipolar plate in the fuel cell stack; the second surface of the first polar plate and the fourth surface of the second polar plate are jointed together in the bipolar plate; the first flow channel on the first surface of the first polar plate comprises an S-shaped section, and the third flow channel on the third surface of the second polar plate does not comprise an S-shaped section; the S-shaped section comprises a fourth section, a fifth section and a sixth section, the length of the fifth section is more than 3 times the width of the sixth section, in the fuel cell stack, the fluid flows through the fourth section, the fifth section and the sixth section in sequence, the included angle formed by the flow direction in the fourth section and the flow direction in the sixth section is in the interval of [0 degrees and 30 degrees ], the included angle formed by the flow direction in the fourth section and the flow direction in the fifth section is in the interval of [60 degrees and 120 degrees ], and the included angle formed by the flow direction in the fifth section and the flow direction in the sixth section is in the interval of [60 degrees and 120 degrees ];

7. The bipolar plate of claim 6, wherein a coolant dam is disposed on the second plate, the coolant dam being a fourth reference plane formed by blocking a portion of the fourth flow channels.

8. A bipolar plate as claimed in claim 1 or 6, wherein the synchronization relief zone has a number of upper or lower support lands therein; the upper support table is a second reference surface formed by blocking a part of the second flow passage, and the lower support table is a fourth reference surface formed by blocking a part of the fourth flow passage.

9. A bipolar plate as claimed in claim 1 or 6, wherein: the first polar plate and the second polar plate are made and formed by a metal or alloy sheet with the thickness of less than 0.5mm through a pressure processing method.

10. A bipolar plate as in claim 6, wherein the second flow channels in said simultaneous undulating region are transverse segments of the second flow channels; the transverse segment is parallel to a fifth segment of the S-shaped segments in the first flow channel;

the bipolar plate comprises at least two synchronous undulating regions;

11. A bipolar plate as in claim 1 or 6, comprising cross flow areas and parallel flow areas, and wherein the projected area of the cross flow areas in the reference plane is larger than the projected area of the parallel flow areas in the reference plane; the reference plane is a plane perpendicular to the thickness direction and is a virtual plane;

12. A bipolar plate as claimed in claim 2 or 7, wherein two or more coolant dams are provided on the second plate, such that the coolant flow path in the space between the first and second plates under the guidance of the coolant dams is S-shaped or serpentine.

13. A fuel cell stack comprising the bipolar plate of any one of claims 1 to 12.

14. A fuel cell power generation system comprising the fuel cell stack according to claim 13.