Fuel cell stack

Abstract

The invention relates to the technical field of fuel cells, and provides a fuel cell stack which comprises a fuel cell stack unit, a first gas channel and a second gas channel, the fuel cell stack unit comprises a membrane electrode and a gas circulation plate which are coaxially and vertically stacked, the membrane electrode and the gas circulation plate are arranged in a staggered mode to form at least two reaction areas, the first gas channel and the second gas channel penetrate through the fuel cell stack unit, and the projection of the first gas channel and the projection of the second gas channel do not coincide. An annular gas channel formed by a plurality of protrusions is arranged on the gas circulation plate. The multi-layer fuel cell reactor in the vertical direction is provided by arranging membrane electrodes and gas circulation plates which are coaxially and vertically stacked, the membrane electrodes and the gas circulation plates are arranged in a staggered manner, and first gas channels and second gas channels are formed in corresponding positions of the membrane electrodes and the gas circulation plates, so that at least two reaction regions are formed, and the multi-layer fuel cell reactor in the vertical direction is provided.

Description

Technical Field

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

[0002] A fuel cell uses hydrogen and oxygen as reactants to generate electricity through a series of electrochemical reactions, and the only products are electricity, heat and pure water, so it is a relatively environmentally friendly power generation device. In addition, since a fuel cell unit 10 has a low voltage and a small current and cannot be used alone, multiple fuel cell units 10 are currently stacked and connected in series to form a fuel cell stack to provide a more compact structure and easier product design.

[0003] At present, the mainstream flow channel structure design is mostly serpentine flow channel, such as Figure 1 As shown, the electrode plate is used to introduce fuel gas such as hydrogen and oxygen into the fuel cell unit 10 for electrochemical reaction. Among them, flow channels 12a and 12b are designed around the electrode plate, which are the entrance and exit of the fuel gas into the fuel cell unit 10. The electrode plate is also distributed with a branch channel 13, which is connected to the flow channels 12a and 12b, so that the fuel gas enters from the flow channel 12a, and is guided by the branch channel 13 to be evenly distributed in the fuel cell unit 10. After the electrochemical reaction, its by-products can be guided back to the flow channel 12b through the branch channel 13 and discharged. Figure 2 and Figure 3 As shown, the fuel cell stack is formed by stacking a plurality of fuel cell units 10, and the stacked fuel cell stack can make each flow channel 12 stacked to form a main flow channel 14, and the main flow channel 14 can be further divided into an inlet main flow channel 141 and an outlet main flow channel 142. In the prior art, according to the relevant position of the main flow channel 14, it can be divided into the following Figure 2 The U-shaped flow channel shown in Figure 3 The Z-type flow channel shown.

[0004] Regardless of the form of the main channel, there are problems such as large inlet and outlet pressure drop and slow dynamic response. It is difficult for the fuel gas to be evenly diverted to the entire main channel. First, when the width of the main channel is fixed, the flow rate of the diverter channels at the head and tail ends of the main channel in the fuel cell stack is mostly the smallest, and the flow rate of the middle diverter channel is large, so that each fuel cell unit cannot achieve the best power generation efficiency. Secondly, the power generation status of the fuel cell unit is independent and difficult to control. Therefore, if the power generation efficiency of each fuel cell unit can be improved individually, the overall fuel cell stack efficiency can be improved. In terms of space utilization, the plates of the stack structure on the market are mostly placed vertically and stacked horizontally, which is suitable for spaces with large horizontal lengths and low vertical heights, and the design requirements for space are relatively simple.

[0005] It can be seen that the above-mentioned existing fuel cell stack main channel design method still has inconveniences and defects in method and use, and it is urgent to be further improved. In order to solve the above-mentioned problems, relevant manufacturers have spared no effort to seek solutions, but for a long time, no suitable design has been developed, and general methods have no appropriate methods to solve the above problems. This is obviously a problem that relevant industry players are eager to solve. Therefore, how to create a new fuel cell stack main channel design method and fuel cell stack structure is one of the current important research and development topics, and has also become a goal that the current industry urgently needs to improve. Summary of the invention

[0006] In order to solve the deficiencies existing in the above-mentioned prior art, the present invention provides a fuel cell stack, including a fuel cell stack unit and a first gas channel and a second gas channel for the circulation of a first gas and a second gas; the fuel cell stack unit includes a coaxially vertically stacked membrane electrode and a gas circulation plate, the membrane electrode and the gas circulation plate are staggered to form at least two reaction areas, the first gas channel and the second gas channel are arranged through the fuel cell stack unit, and the projections of the first gas channel and the second gas channel do not overlap, and a ring-shaped gas channel formed by a number of protrusions is arranged on the gas circulation plate.

[0007] In one embodiment, the gas circulation plate includes an anode upper end plate, a bipolar plate and a cathode lower end plate, and the membrane electrode includes a first membrane electrode and a second membrane electrode, and the anode upper end plate, the first membrane electrode, the bipolar plate, the second membrane electrode and the cathode lower end plate are tightly connected from top to bottom. By using the above technology, each end plate is tightly connected to the membrane electrode, which can effectively prevent gas overflow and improve the reaction efficiency of the gas.

[0008] In one embodiment, the anode upper end plate is provided with a first gas inlet, and the first gas inlet is connected to a first gas channel opened in the anode upper end plate.

[0009] In one embodiment, the bipolar plate includes a cathode bipolar plate and an anode bipolar plate, the cathode bipolar plate is arranged close to the first membrane electrode, and the anode bipolar plate is arranged close to the second membrane electrode; both the anode bipolar plate and the cathode bipolar plate are provided with a first gas channel and a second gas channel.

[0010] In one embodiment, the cathode bipolar plate includes a first surface of the cathode bipolar plate and a second surface of the cathode bipolar plate; a first gas baffle is arranged on the first gas channel of the first surface of the cathode bipolar plate, and the first gas baffle on the first surface of the cathode bipolar plate is tightly fitted with the first membrane electrode; a first gas baffle is arranged on the first gas channel of the second surface of the cathode bipolar plate, and a second gas baffle is arranged above the second gas channel on the second surface of the cathode bipolar plate; the anode bipolar plate includes a first surface of the anode bipolar plate and a second surface of the anode bipolar plate; a first gas baffle and a second gas baffle are arranged above the first gas channel and the second gas channel on the first surface of the anode bipolar plate; the first gas baffle and the second gas baffle on the second surface of the cathode bipolar plate are respectively arranged opposite to the first gas baffle and the second gas baffle on the first surface of the anode bipolar plate; a second gas baffle is arranged on the second gas channel on the second surface of the anode bipolar plate, and the second gas baffle is completely fitted with the second membrane electrode.

[0011] By adopting the above technology, the first gas baffle and the second gas baffle are arranged between the above different gas flow plates and different surfaces of different membrane electrodes to form flow channels in which the first gas and the second gas do not overlap, so that the fuel cell reactor can be provided with multiple reaction zones at the same time.

[0012] In one embodiment, a first gas recovery device is also provided, including two coaxially arranged first annular pipes and a first vertical pipe, the first vertical pipe connects the two first annular pipes, a plurality of first gas interfaces are provided inside the first annular pipe, and a first gas outlet is provided at the bottom of the first vertical pipe; a plurality of first gas holes are provided circumferentially at a preset distance between the contact surface of the anode upper end plate and the first membrane electrode, a plurality of first gas holes are provided circumferentially at a preset distance between the contact surface of the anode bipolar plate and the second membrane electrode, and the plurality of first gas holes are connected to the plurality of first gas interfaces. By adopting the above technology, the first gas after the reaction is discharged by providing a first gas inlet and a plurality of circumferentially arranged first gas holes, thereby improving the recovery efficiency of the unreacted gas.

[0013] In one embodiment, a second gas inlet is provided on the cathode lower end plate, and the second gas inlet is connected to a second gas channel provided on the cathode lower end plate.

[0014] In one embodiment, a second gas recovery device is also provided, including two coaxially arranged second annular pipes and a second vertical pipe, the second vertical pipe connects the two second annular pipes, a plurality of second gas interfaces are provided inside the second annular pipe, and a second gas outlet is provided at the bottom of the second vertical pipe; a plurality of second gas holes are provided circumferentially at a preset distance between the contact surface of the cathode lower end plate and the second membrane electrode, a plurality of second gas holes are provided circumferentially at a preset distance between the contact surface of the cathode bipolar plate and the first membrane electrode, and the plurality of second gas holes are connected to the plurality of second gas interfaces. By adopting the above technology, the second gas after the reaction is discharged by providing a second gas inlet and a plurality of circumferentially arranged second gas holes, thereby improving the recovery efficiency of the unreacted gas.

[0015] In one embodiment, a cooling device is also provided, including a plurality of cooling channels and a cooling recovery device, wherein the cooling channels include a first cooling channel provided inside the upper end plate of the anode, a second cooling channel provided inside the bipolar plate, and a third cooling channel provided inside the lower end plate of the anode, and the side walls of the first cooling channel, the second cooling channel, and the third cooling channel are each provided with a liquid inlet hole and a plurality of liquid outlet holes, and the liquid inlet holes and the liquid outlet holes are circumferentially arranged at the same preset distance. By adopting the above technology, a design structure with one cooling channel on one side and one gas channel on the other side is adopted, so that the gas is evenly distributed in the channel and the gas can be effectively cooled evenly.

[0016] In one embodiment, the cooling recovery device includes three coaxially arranged third annular pipes and a third vertical pipe and a fourth vertical pipe connected to the third annular pipes. Each inner circle of the third annular pipe is provided with a liquid inlet interface and a plurality of liquid outlet interfaces. The top of the third vertical pipe is provided with a liquid inlet, and the third vertical pipe connects the liquid inlet interfaces of the three annular pipes. The bottom of the fourth vertical pipe is provided with a liquid outlet, and the fourth vertical pipe connects any liquid outlet interface of the three annular pipes. The liquid inlet interface is connected to the liquid inlet hole of the cooling channel, and the liquid outlet interface is connected to the liquid outlet hole of the cooling channel. Using the above technology, the liquid inlet hole and the plurality of liquid outlet holes are arranged circumferentially at the same preset distance, so that the coolant can be better distributed throughout the entire heating area to achieve the purpose of efficient heat dissipation.

[0017] Based on the above, compared with the prior art, a fuel cell reactor provided by the present invention is provided, by arranging coaxially vertically stacked membrane electrode and gas circulation plates, and the flow channel of the gas circulation plate is an annular gas channel, wherein the membrane electrode and the gas circulation plate are staggered, and a first gas channel and a second gas channel are arranged at corresponding positions of the membrane electrode and the gas circulation plate to form at least two reaction zones, thereby providing a vertical multilayer fuel cell reactor with good application value.

[0018] Other features and beneficial effects of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other beneficial effects of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. The positional relationship of the drawings in the following description, unless otherwise specified, is based on the direction in which the components are drawn in the diagram.

[0020] Figure 1 It is a schematic diagram of the structure of the electrode plate flow channel in the prior art; Figure 2 It is a structural schematic diagram of a U-shaped flow channel in the prior art; Figure 3 It is a structural schematic diagram of a Z-type flow channel in the prior art; Figure 4 A front view of a fuel cell unit of a fuel cell stack provided by one embodiment of the present invention; Figure 5 A front view of a fuel cell stack provided by one embodiment of the present invention; Figure 6 A top view of a fuel cell stack provided in one embodiment of the present invention; Figure 7 for Figure 6 Cross-section in EE direction; Figure 8 A bottom view of a fuel cell stack provided by one embodiment of the present invention; Fig. 9 A schematic diagram of the three-dimensional structure of a fuel cell stack provided in one embodiment of the present invention; Fig.10 A schematic diagram of the structure of a membrane electrode in a first direction provided by an embodiment of the present invention; Fig.11 A schematic diagram of the structure of a membrane electrode in a second direction provided by an embodiment of the present invention; Fig.12 An exploded view of a fuel cell unit of a fuel cell stack in a first direction provided by an embodiment of the present invention; Fig.13 An exploded view of a fuel cell unit of a fuel cell stack in a second direction provided by an embodiment of the present invention; Fig.14A schematic structural diagram of a first gas recovery device provided in one embodiment of the present invention; Fig.15 A schematic structural diagram of a second gas recovery device provided in one embodiment of the present invention; Fig.16 A schematic structural diagram of a cooling recovery device provided in one embodiment of the present invention.

[0021] Reference numerals: DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments; the technical features designed in different implementation modes of the present invention described below can be combined with each other as long as they do not conflict with each other; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0023] In the description of the present invention, it should be noted that all terms (including technical terms and scientific terms) used in the present invention have the same meanings as those generally understood by ordinary technicians in the field to which the present invention belongs, and should not be understood as limitations on the present invention; it should be further understood that the terms used in the present invention should be understood to have the same meanings as these terms in the context of this specification and in the relevant fields, and should not be understood in an idealized or overly formal sense, unless explicitly defined in this invention.

[0024] The present invention provides a fuel cell stack, such as Figure 4 As shown, it includes a fuel cell stack unit 10 and a first gas channel 20 and a second gas channel 30 for the circulation of a first gas and a second gas; the fuel cell stack unit 10 includes a coaxially vertically stacked membrane electrode and a gas circulation plate 50, the membrane electrode and the gas circulation plate 50 are staggered to form at least two reaction areas, the first gas channel 20 and the second gas channel 30 are arranged throughout the fuel cell stack unit 10, and the projections of the first gas channel 20 and the second gas channel 30 do not overlap, and an annular gas channel 61 formed by a plurality of protrusions 60 is arranged on the gas circulation plate 50.

[0025] Specifically, the cross section of the gas circulation plate 50 is circular, and the protrusions 60 are arranged in a ring between the gas circulation plates 50, and there are gaps for gas circulation between the protrusions 60 of the same ring, and the protrusions 60 between different rings are arranged in a staggered manner, so that the gas can circulate more fully on the plate surface. The first gas is hydrogen, the anode reaction gas, and the second gas is oxygen, the cathode reaction gas. During specific operations, the gas selection can be carried out according to the specific reaction, and is not limited to the above gases.

[0026] In one embodiment, if Figure 5 , Figure 6 and Figure 7 As shown, the gas circulation plate 50 includes an anode upper end plate 51, a bipolar plate 52 and a cathode lower end plate 53, and the membrane electrode includes a first membrane electrode 41 and a second membrane electrode 42. From top to bottom, the anode upper end plate 51, the first membrane electrode 41, the bipolar plate 52, the second membrane electrode 42 and the cathode lower end plate 53 are tightly connected.

[0027] Specifically, Figure 6 , Figure 7 , Figure 8 and Fig. 9 As shown, the fuel cell reactor is also provided with a fixing assembly 11, which includes an upper baffle 111, a lower baffle 112 and fixing bolts 113. The upper baffle 111 is installed on the top of the anode upper end plate 51, and the lower baffle 112 is installed on the bottom of the cathode lower end plate 53. The upper baffle 111 and the lower baffle 112 are spaced apart by a preset distance and are provided with bolt holes 114 in the circumferential direction. The fixing bolts 113 pass through the bolt holes 114 to connect the upper baffle 111 and the lower baffle 112. The upper baffle 111 and the lower baffle 112 cooperate to compress and fix the internal reactor stack to prevent gas leakage between the gas circulation plates 50. Preferably, eight groups of fixing bolts 113 are provided, and eight bolt holes 114 are provided in the circumferential direction to fix the fixing bolts 113. This fixing structure allows the fuel cell stack to be placed horizontally or vertically as a whole, providing a variety of options for space placement.

[0028] In one embodiment, if Figure 1 , Fig.10 and Fig.11 As shown, the membrane electrode 40 is provided with a first gas channel 20 and a second gas channel 30. Specifically, the cross section of the membrane electrode 40 is a circle with a diameter of 15 mm, and includes, from top to bottom, an anode gas diffusion layer, an anode catalyst layer, a cathode catalyst layer, a cathode gas diffusion layer and a proton exchange membrane, the above five-layer structure is tightly fitted, and is provided with a first gas channel 20 and a second gas channel 30 running through.

[0029] In one embodiment, if Fig.12As shown, the anode upper end plate 51 is provided with a first gas inlet 21, and the first gas inlet 21 is connected to the first gas channel 20 opened in the anode upper end plate 51. Specifically, the first surface 51a of the anode upper end plate, that is, the surface away from the fuel cell reactor, is a plane, without a protrusion 60, and is provided with a first gas inlet 21, and a distribution head 22 is also connected above the first gas inlet 21, and the distribution head 22 is bolted to the first surface 51a of the anode upper end plate through the distribution head 22. A plurality of protrusions 60 are provided on the second surface 51b of the anode upper end plate to form a first gas annular flow channel, and there is a height difference between the first gas channel 20 on the second surface 51b of the anode upper end plate and the first membrane electrode 41, and the first gas flows between the first gas channel 20 on the second surface 51b of the anode upper end plate and the first membrane electrode 41, and reacts at the anode of the first membrane electrode 41.

[0030] In one embodiment, if Fig.12 and Fig.13 As shown, the bipolar plate 52 includes an anode bipolar plate 522 and a cathode bipolar plate 521. The cathode bipolar plate 521 is arranged close to the first membrane electrode 41, and the anode bipolar plate 522 is arranged close to the second membrane electrode 42. Both the anode bipolar plate 522 and the cathode bipolar plate 521 are provided with a first gas channel 20 and a second gas channel 30.

[0031] In a specific implementation, the fuel cell stack unit 10 can be formed into multiple reaction areas by providing multiple layers of bipolar plates 52 .

[0032] like Fig.12 and Fig.13 As shown, the cathode bipolar plate 521 includes a first surface 521a of the cathode bipolar plate and a second surface 521b of the cathode bipolar plate; a first gas baffle 23 is arranged on the first gas channel 20 of the first surface 521a of the cathode bipolar plate, and the first gas baffle 23 of the first surface 521a of the cathode bipolar plate is tightly fitted with the first membrane electrode 41, so that the first gas cannot flow between the first surface 521a of the cathode bipolar plate and the first membrane electrode 41, but the second gas can flow between the first surface 521a of the cathode bipolar plate and the first membrane electrode 41.

[0033] The anode bipolar plate 522 includes a first surface 522a of the anode bipolar plate and a second surface 522b of the anode bipolar plate; a second gas baffle 33 is arranged on the second gas channel 30 of the second surface 522b of the anode bipolar plate, and the second gas baffle 33 is completely fitted with the second membrane electrode 42, so that the first gas can flow between the second surface 522b of the anode bipolar plate and the second membrane electrode 42, but the second gas cannot flow between the second surface 522b of the anode bipolar plate and the second membrane electrode 42.

[0034] The first gas channel 20 of the second surface 521b of the cathode bipolar plate is provided with a first gas baffle 23, and a second gas baffle 33 is provided above the second gas channel 30 of the second surface 521b of the cathode bipolar plate; the first gas baffle 23 and the second gas baffle 33 are provided above the first gas channel 20 and the second gas channel 30 of the first surface 522a of the anode bipolar plate; the first gas baffle 23 and the second gas baffle 33 of the second surface 521b of the cathode bipolar plate are respectively arranged opposite to the first gas baffle 23 and the second gas baffle 33 of the first surface 522a of the anode bipolar plate, so that both the first gas and the second gas cannot flow between the second surface 521b of the cathode bipolar plate and the first surface 522a of the anode bipolar plate.

[0035] In a specific implementation, the cross-sections of the first gas baffle 23 and the second gas baffle 33 are the same as the first gas channel 20 and the second gas channel 30, both of which are semi-annular. The cross-sections of the first gas baffle 23 and the second gas baffle 33 are spliced ​​to form a circular gas baffle. In one embodiment, the height of the gas baffle is equal to the height of the protrusion 60.

[0036] In one embodiment, if Fig.13 As shown, the cathode lower end plate 53 is provided with a second gas inlet 31, and the second gas inlet 31 is connected to the second gas channel 30 provided in the cathode lower end plate 53. Specifically, the second surface of the cathode lower end plate 53, that is, the surface away from the fuel cell reactor, is a plane, and no protrusion 60 is provided. A second gas inlet 31 is provided, and a distribution head 22 is also connected above the second gas inlet 31. The distribution head 22 is bolted to the first surface of the cathode lower end plate 53. The first surface of the cathode lower end plate 53 is provided with a plurality of protrusions 60, forming a second gas annular flow channel. There is a height difference between the second gas channel 30 on the first surface 53a of the cathode lower end plate and the second membrane electrode 42. The second gas flows between the second gas channel 30 on the first surface 53a of the cathode lower end plate and the second membrane electrode 42, and reacts at the cathode of the second membrane electrode 42.

[0037] The flow order of the first gas is: Fig.12As shown, the first gas enters the fuel cell reactor from the first gas inlet 21 of the anode upper end plate 51, flows between the second surface 51b of the anode upper end plate and the first surface 41a of the first membrane electrode, reacts at the anode of the first membrane electrode 41, and then passes through the first membrane electrode 41. Because the first gas flow channel of the first surface 521a of the cathode bipolar plate is tightly fitted with the second surface of the first membrane electrode 41, the first gas cannot diffuse from the first surface 521a of the cathode bipolar plate, but passes through the cathode bipolar plate 521 and the anode bipolar plate 522 to reach the second surface 522b of the anode bipolar plate. There is a gap between the first gas channel 20 of the second surface 522b of the anode bipolar plate and the second membrane electrode 42. The first gas diffuses on the second surface 522b of the anode bipolar plate and reacts in the anode area of ​​the second membrane electrode 42.

[0038] The flow order of the second gas is: Fig.13 As shown, the second gas enters the fuel cell reactor from the second air inlet of the cathode lower end plate 53, flows between the first surface 53a of the cathode lower end plate and the second surface 42b of the second membrane electrode, reacts at the cathode of the second membrane electrode 42, and then passes through the second membrane electrode 42. Because the second gas flow channel of the second surface 522b of the anode bipolar plate is tightly fitted with the first surface 42a of the second membrane electrode, the second gas cannot diffuse from the second surface 522b of the anode bipolar plate, but passes through the anode bipolar plate 522 and the cathode bipolar plate 521 to reach the first surface 521a of the cathode bipolar plate. There is a gap between the second gas channel 30 of the first surface 521a of the cathode bipolar plate and the first membrane electrode 41. The first gas diffuses on the first surface 521a of the cathode bipolar plate and reacts in the cathode area of ​​the first membrane electrode 41.

[0039] Preferably, the anode bipolar plate 522 and the cathode bipolar plate 521 can be made into an integral bipolar plate 52 or can be designed as separate splicing.

[0040] Specifically, the first gas baffle 23 and the second gas baffle 33 are arranged between the different gas flow plates 50 and different surfaces of the different membrane electrode 40 to form flow channels in which the first gas and the second gas do not overlap, so that the fuel cell reactor can be provided with multiple reaction zones at the same time.

[0041] In one embodiment, if Fig.14As shown, the fuel cell stack is also provided with a first gas recovery device 70, including two coaxially arranged first annular pipes 71 and a first vertical pipe 72, the first vertical pipe 72 connects the two first annular pipes 71, a plurality of first gas interfaces 73 are arranged inside the first annular pipe 71, and a first gas outlet 74 is arranged at the bottom of the first vertical pipe 72. A plurality of first gas holes 75 are circumferentially provided at a preset distance between the contact surface of the anode upper end plate 51 and the first membrane electrode 41, and a plurality of first gas holes 75 are circumferentially provided at a preset distance between the contact surface of the anode bipolar plate 522 and the second membrane electrode 42, and the plurality of first gas holes 75 are connected to the plurality of first gas interfaces 73.

[0042] Preferably, there are eight first gas holes 75 and first gas interfaces 73, and the first gas holes 75 and the first gas interfaces 73 are circumferentially arranged at the same preset distance around the anode upper end plate 51 and the anode bipolar plate 522. It should be noted that the number of the first gas holes 75 and the first gas interfaces 73 is not limited to eight, and can also be six, ten, etc.

[0043] Specifically, the hydrogen in different reaction areas is connected and discharged through the first plurality of first annular pipes 71 and the first vertical pipe 72 of the first gas recovery device 70, and the gas recovery is integrated, which facilitates the recycling of the reaction gas, and the first gas hole 75 and the first gas interface 73 are arranged circumferentially at the same distance to solve the problem of uneven gas distribution in the gas flow channel and improve the reaction efficiency of the gas. At the same time, the first gas enters from the first gas channel 20 in the middle, and the eight circumferential outlets are evenly distributed to ensure that the gas diffuses evenly outward. The cooling device can evenly cool the gas in all directions, and the gas entering the middle can purge the water generated in the flow channel to avoid flooding.

[0044] In one embodiment, if Fig.15 As shown, the fuel cell stack is also provided with a second gas recovery device 80, including two coaxially arranged second annular pipes 81 and a second vertical pipe 82, the second vertical pipe 82 connects the two second annular pipes 81, a plurality of second gas interfaces 83 are arranged inside the second annular pipe 81, and a second gas outlet 84 is arranged at the bottom of the second vertical pipe 82.

[0045] A plurality of second gas holes 85 are circumferentially provided at a preset distance between the contact surface between the cathode lower end plate 53 and the second membrane electrode 42 , and a plurality of second gas holes 85 are circumferentially provided at a preset distance between the contact surface between the cathode bipolar plate 521 and the first membrane electrode 41 . The plurality of second gas holes 85 are connected to a plurality of second gas interfaces 83 .

[0046] In one embodiment, the fuel cell stack is further provided with a cooling device 90, such as Fig. 9 and Fig.12As shown, it includes a plurality of cooling channels 91 and a cooling recovery device 92. The cooling channel 91 includes a first cooling channel 911 arranged inside the anode upper end plate 51, a second cooling channel 912 arranged inside the bipolar plate 52, and a third cooling channel 912 arranged inside the anode lower end plate. The side walls of the first cooling channel 911, the second cooling channel 912 and the third cooling channel 91 are each provided with a liquid inlet hole 914 and seven liquid outlet holes 915, and the liquid inlet hole 914 and the liquid outlet hole 915 are circumferentially arranged at the same preset distance.

[0047] like Fig.16 As shown, the cooling recovery device 92 includes three coaxially arranged annular pipes and a third vertical pipe 922 and a fourth vertical pipe connected to the third annular pipe 921. Each inner circle of the third annular pipe 921 is provided with a liquid inlet interface 924 and seven liquid outlet interfaces 925. The top of the third vertical pipe 922 is provided with a liquid inlet 926. The third vertical pipe 922 connects the liquid inlet interfaces 924 of the three annular pipes. The bottom end of the fourth vertical pipe is provided with a liquid outlet 927. The fourth vertical pipe connects any liquid outlet interface 925 of the three annular pipes; the liquid inlet interface 924 is connected to the liquid inlet hole 914 of the cooling channel 91, and the liquid outlet interface 925 is connected to the liquid outlet hole 915 of the cooling channel 91.

[0048] In specific implementation, the coolant enters the first cooling channel 911, the second cooling channel 912 and the third cooling channel 91 from the liquid inlet 926 of the third vertical pipe 922, and the fourth vertical pipe is connected to the liquid outlet 927 which is the longest in a straight line distance from the third vertical pipe 922, so that the coolant can flow fully and comprehensively in the cooling channel 91, and then flow out from the liquid outlet hole 915 through the liquid outlet 927 of the fourth vertical pipe.

[0049] The overall working principle of the fuel cell stack: When the fuel cell stack is working, hydrogen and oxygen are introduced from the inlets of the distribution heads 22 of the anode upper end plate 51 and the cathode lower end plate 53, respectively, and lead to eight outlets through the flow channels, and are evenly distributed throughout the annular gas channel 61. At the same time, the anode upper end plate 51, the bipolar plate 52 and the cathode lower end plate 53 are guided and evenly distributed to the membrane electrode 40, and an electrochemical reaction is realized inside the membrane electrode 40. The gas that does not participate in the reaction converges in the first annular pipe and the second annular pipe through the eight outlets, and then is collected and reused at the outlets of the first annular pipe and the second annular pipe. The inlet and outlet of the cooling recovery device 92 are set up one above and one below. After the coolant is introduced from the inlet, it enters the eight outlets of the cooling channel to achieve uniform heat dissipation, and then flows out from the lower outlet on the opposite side to achieve an efficient cooling effect.

[0050] In summary, compared with the prior art, the fuel cell stack provided by the present invention has the following beneficial effects: 1) The bipolar plate structure is optimized, and a design structure with a cooling channel on one side and a gas channel on the other side is adopted. The gas channel adopts a four-layer ring design so that the gas can be evenly distributed, making the gas distribution in the gas channel more uniform than that in the serpentine channel.

[0051] 2) The gas flow channel has one inlet and eight outlets, which improves the recovery efficiency of unreacted gas.

[0052] 3) Compared with the serpentine flow channel, the circular flow channel is more beautiful, symmetrical and material-saving. The inlet is in the middle and the inlet flow rate is large, which can efficiently blow water to the outlet to avoid flooding.

[0053] 4) The liquid cooling channel has one inlet and seven outlets, so that the coolant can be better distributed throughout the entire heating area to achieve efficient heat dissipation.

[0054] In addition, those skilled in the art should understand that, although there are many problems in the prior art, each embodiment or technical solution of the present invention can be improved in only one or several aspects, without having to solve all the technical problems listed in the prior art or background technology at the same time. Those skilled in the art should understand that the content not mentioned in a claim should not be used as a limitation on the claim.

[0055] Although the terms such as fuel cell stack unit, fixing assembly, upper baffle, lower baffle, fixing bolt, bolt hole, first gas channel, first gas inlet, distribution head, second gas channel, second gas inlet, membrane electrode, first membrane electrode, first membrane electrode first surface, first membrane electrode second surface, second membrane electrode, second membrane electrode first surface, second membrane electrode second surface, gas circulation plate, anode upper end plate, anode upper end plate first surface, anode upper end plate second surface, bipolar plate, cathode bipolar plate, cathode bipolar plate first surface, cathode bipolar plate second surface, anode bipolar plate, anode bipolar plate first surface and anode bipolar plate second surface are used more frequently in this article, the possibility of using other terms is not excluded. These terms are used only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional limitation is contrary to the spirit of the present invention; the terms "first", "second", etc. (if any) in the description and claims of the embodiments of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fuel cell stack, characterized in that: It includes a fuel cell stack unit and a first gas channel and a second gas channel for the circulation of a first gas and a second gas; the fuel cell stack unit includes a coaxially vertically stacked membrane electrode and a gas circulation plate, the membrane electrode and the gas circulation plate are staggered to form at least two reaction areas, the first gas channel and the second gas channel are arranged throughout the fuel cell stack unit, and the projections of the first gas channel and the second gas channel do not overlap, and the gas circulation plate is provided with a plurality of annular gas channels formed by protrusions.

2. The fuel cell stack according to claim 1, characterized in that: The gas circulation plate includes an anode upper end plate, a bipolar plate and a cathode lower end plate, and the membrane electrode includes a first membrane electrode and a second membrane electrode. From top to bottom, the anode upper end plate, the first membrane electrode, the bipolar plate, the second membrane electrode and the cathode lower end plate are tightly connected.

3. The fuel cell stack according to claim 2, characterized in that: The bipolar plate includes a cathode bipolar plate and an anode bipolar plate. The cathode bipolar plate is arranged close to the first membrane electrode, and the anode bipolar plate is arranged close to the second membrane electrode. Both the anode bipolar plate and the cathode bipolar plate are provided with a first gas channel and a second gas channel.

4. The fuel cell stack according to claim 3, characterized in that: The cathode bipolar plate comprises a first surface of the cathode bipolar plate and a second surface of the cathode bipolar plate, a first gas baffle is provided on the first gas channel of the first surface of the cathode bipolar plate, and the first gas baffle on the first surface of the cathode bipolar plate is closely attached to the first membrane electrode; the first gas channel of the second surface of the cathode bipolar plate is provided with the first gas baffle, and a second gas baffle is provided above the second gas channel of the second surface of the cathode bipolar plate; The anode bipolar plate comprises a first surface of the anode bipolar plate and a second surface of the anode bipolar plate; the first gas baffle and the second gas baffle are arranged above the first gas channel and the second gas channel on the first surface of the anode bipolar plate; the first gas baffle and the second gas baffle on the second surface of the cathode bipolar plate are respectively arranged opposite to the first gas baffle and the second gas baffle on the first surface of the anode bipolar plate; The second gas baffle is provided on the second gas channel on the second surface of the anode bipolar plate, and the second gas baffle is completely in contact with the second membrane electrode.

5. The fuel cell stack according to claim 2, characterized in that: The anode upper end plate is provided with a first gas inlet, and the first gas inlet is connected to the first gas channel opened in the anode upper end plate.

6. The fuel cell stack according to claim 4, characterized in that: A first gas recovery device is also provided, comprising two coaxially arranged first annular pipes and a first vertical pipe, wherein the first vertical pipe connects the two first annular pipes, a plurality of first gas interfaces are provided inside the first annular pipe, and a first gas outlet is provided at the bottom of the first vertical pipe; A plurality of first gas holes are circumferentially provided at a preset distance between the contact surface between the anode upper end plate and the first membrane electrode, and a plurality of first gas holes are circumferentially provided at a preset distance between the contact surface between the anode bipolar plate and the second membrane electrode, and the plurality of first gas holes are connected to the plurality of first gas interfaces.

7. The fuel cell stack according to claim 2, characterized in that: The cathode lower end plate is provided with a second gas inlet, and the second gas inlet is connected to a second gas channel provided in the cathode lower end plate.

8. The fuel cell stack according to claim 5, characterized in that: A second gas recovery device is also provided, comprising two coaxially arranged second annular pipes and a second vertical pipe, wherein the second vertical pipe connects the two second annular pipes, a plurality of second gas interfaces are provided inside the second annular pipe, and a second gas outlet is provided at the bottom of the second vertical pipe; The contact surface between the cathode lower end plate and the second membrane electrode is circumferentially provided with a preset distance, and the contact surface between the cathode bipolar plate and the first membrane electrode is circumferentially provided with a preset distance, and the second gas holes are connected to the second gas interfaces.

9. The fuel cell stack according to claim 1, characterized in that: A cooling device is also provided, including a plurality of cooling channels and a cooling recovery device, the cooling channels including a first cooling channel arranged inside the upper end plate of the anode, a second cooling channel arranged in the bipolar plate, and a third cooling channel arranged inside the lower end plate of the anode, the side walls of the first cooling channel, the second cooling channel and the third cooling channel are each provided with a liquid inlet hole and a plurality of liquid outlet holes, and the liquid inlet holes and the liquid outlet holes are circumferentially arranged at the same preset distance.

10. The fuel cell stack according to claim 9, characterized in that: The cooling recovery device comprises three coaxially arranged third annular pipes and a third vertical pipe and a fourth vertical pipe connected to the third annular pipes, wherein each inner circle of the third annular pipe is provided with a liquid inlet interface and a plurality of liquid outlet interfaces, the top of the third vertical pipe is provided with a liquid inlet, the third vertical pipe connects the liquid inlet interfaces of the three annular pipes, the bottom of the fourth vertical pipe is provided with a liquid outlet, the fourth vertical pipe connects any of the liquid outlet interfaces of the three annular pipes; The liquid inlet interface is connected to the liquid inlet hole of the cooling channel, and the liquid outlet interface is connected to the liquid outlet hole of the cooling channel.

Images