CN110165270B - Fuel cell stack and fuel cell stack system having the same - Google Patents

Abstract

The invention provides a fuel cell stack and a fuel cell stack system with the same, wherein the fuel cell stack comprises a first insulating plate, a first current collecting plate, a plurality of cells, a second current collecting plate and a second insulating plate which are sequentially arranged, the first current collecting plate is assembled on the first insulating plate, the second current collecting plate is assembled on the second insulating plate, the first current collecting plate and/or the second current collecting plate comprises a plurality of current sub-collecting plates which are arranged at intervals, and each current sub-collecting plate can collect current of each cell in a region corresponding to the current sub-collecting plate. The technical scheme of this application has effectively solved among the prior art fuel cell's performance and can only judge through the holistic voltage of battery pile or judge through the voltage of each section battery in the battery pile, can't learn the inside specific performance distribution's of battery pile problem among the judgement process.

Description

Fuel cell stack and fuel cell stack system having the same

Technical Field

The invention relates to the field of batteries, in particular to a fuel cell stack and a fuel cell stack system with the same.

Background

In the prior art, a fuel cell is an environment-friendly, efficient, long-life power generation device. Taking a Proton Exchange Membrane Fuel Cell (PEMFC) as an example, fuel gas enters from the anode side, hydrogen atoms lose electrons at the anode to become protons, the protons pass through the proton exchange membrane to reach the cathode, the electrons also reach the cathode via an external circuit, and the protons, the electrons and oxygen combine at the cathode to produce water. The fuel cell converts chemical energy into electric energy in a non-combustion mode, and the direct power generation efficiency can reach 45% because the fuel cell is not limited by Carnot cycle. The fuel cell system integrates modules of power management, thermal management and the like, and has the characteristics of heat, electricity, water and gas overall management. Fuel cell system products range from stationary power stations, to mobile power supplies; from electric automobiles, to space shuttles; there is a wide range of applications from military equipment to civilian products.

In the existing fuel cell structure, bipolar plates and membrane electrodes are generally overlapped in sequence to form a multi-section or even tens of sections of cell stacks, thereby forming a power generation device with higher power.

As shown in fig. 1, the fuel cell stack structure is formed by stacking a bipolar plate B and a membrane electrode 20, wherein the upper surface of the bipolar plate is an anode, the lower surface of the bipolar plate is a cathode, the upper surface of the membrane electrode is a cathode, the lower surface of the membrane electrode is an anode, current collectors C1 and C2 are arranged at two ends of the stack to collect the current of the whole stack, C1 is a cathode current collector (cell anode), and C2 is an anode current collector (cell cathode). Wherein, the membrane electrode is a place for electrochemical reaction and consists of a catalyst (generally Pt/C) and a proton exchange membrane. Wherein, the bipolar plate is carved with a flow channel to evenly distribute the reaction gas.

In the prior art, a graphite carved bipolar plate is generally used, as shown in fig. 2, a cross-sectional structure diagram of the carved graphite bipolar plate is shown, wherein B1 is an anode plate, B2 is a cathode plate, B3 is a flow channel of the anode plate for flowing fuel hydrogen, B4 is a flow channel of the cathode plate for flowing oxidant gas (air or oxygen), and B5 is a flow channel of the other side of the cathode plate for flowing coolant (deionized water).

Fig. 3 shows a cross-sectional structure of a membrane electrode of a fuel cell, where M1 is an anode gas diffusion layer, M2 is an anode catalyst layer, M3 is a proton exchange membrane, M4 is a cathode catalyst layer, and M5 is a cathode gas diffusion layer.

For the design and operation of the existing fuel cell stack, as shown in fig. 4, the performance of the fuel cell can only be determined by the voltage of the whole fuel cell stack or by the voltage of each cell in the fuel cell stack, however, when the performance of the whole fuel cell stack is reduced or a certain voltage is reduced, it cannot be determined at which specific part of a certain cell of the fuel cell has a fault, and thus an accurate and efficient feedback control strategy cannot be proposed. For example, when the stack voltage or the battery voltage drops, there may be a number of causes, such as: firstly, the humidity inside the galvanic pile is too high, so that liquid water is accumulated, and mass transfer of reaction gas is hindered, namely flooding; secondly, the inside of the galvanic pile is excessively dried, so that the internal resistance of the membrane is large, and the voltage performance is reduced; third, insufficient flow of reactant gases to the cathode or anode can cause reactant starvation and reduced voltage performance.

As shown in fig. 5, a schematic cross-sectional view of a fuel cell stack cell of the prior art is shown, where An is An anode part, 20 is a membrane electrode, Ca is a cathode part, D is a cooling part, C1 is a cathode current collecting plate, C2 is An anode current collecting plate, Tr1 is the water diffusion behavior from cathode to anode, and Tr2 is the water and electricity migration behavior from anode to cathode. The arrows indicate the direction of fluid or gas flow. The cooling portion passes through the flow passage from the inlet end 57 to the outlet end 56, and the triangle in the cooling portion represents a temperature change from the inlet temperature T to the outlet temperature T + Δ T. Obviously, the hydrogen transport and reaction consumption from the inlet end 31 to the outlet end 34 through the flow channels, and the reaction conditions such as hydrogen concentration, humidity, temperature, etc. cannot be completely consistent in the whole membrane electrode reaction area; the same problem exists with air passing through the flow path from the inlet end 43 to the outlet end 42; meanwhile, through the proton exchange membrane, a complex water heat exchange process (such as processes of Tr1 and Tr 2) exists between the cathode and the anode, and the complexity and the inconsistency of parameter distribution of internal reaction conditions are caused. The inconsistent local reaction conditions and the working environment of the membrane electrode lead to the inconsistent performance of the membrane electrode in different areas and the inconsistent performance of the membrane electrode in different areas, and cause inconsistent life attenuation of each area, and the key for limiting the performance and the life of the fuel cell is the local area with the lowest performance and the fastest performance attenuation.

Therefore, in the prior art, the performance of the fuel cell is judged only by the voltage, and the specific performance distribution inside the stack cannot be obtained, so that the real reaction condition inside the stack cannot be judged, the control strategy of the stack in the power generation system is inaccurate and untimely, the performance of the stack is further deteriorated, the system efficiency is reduced, and the accelerated life attenuation of the stack is caused.

Disclosure of Invention

The invention aims to provide a fuel cell stack and a fuel cell stack system with the same, so as to solve the problem that the performance of a fuel cell in the prior art can only be judged by the voltage of the whole cell stack or the voltage of each cell in the cell stack, and the specific performance distribution in the cell stack cannot be known in the judging process.

In order to achieve the above object, according to one aspect of the present invention, there is provided a fuel cell stack including a first insulating plate, a first current collecting plate, a plurality of cells, a second current collecting plate, and a second insulating plate, which are sequentially disposed, the first current collecting plate being mounted on the first insulating plate, the second current collecting plate being mounted on the second insulating plate, wherein the first current collecting plate and/or the second current collecting plate includes a plurality of current sub-collecting plates disposed at intervals, each of the current sub-collecting plates being capable of collecting current of a region of each of the cells corresponding to the current sub-collecting plate.

Further, the plurality of sub-current plates are parallel to each other, and the plurality of sub-current plates are arranged from top to bottom.

Further, each sub-current plate includes a terminal at an end portion, the terminal protruding from the first insulating plate or the second insulating plate.

Further, the first insulating plate and/or the second insulating plate are formed with a plurality of insertion grooves for receiving the plurality of current sub-collectors, a first end of each insertion groove is a closed end, a second end of each insertion groove is an open end, and the terminal extends from the open end.

Further, a surface of each sub-current collecting plate is coplanar with a surface of the first insulating plate or the second insulating plate in a direction toward the plurality of batteries.

Furthermore, each battery comprises an anode plate, a membrane electrode and a cathode plate which are arranged in sequence; in two adjacent batteries, the cathode plate of one battery is adjacent to the anode plate of the other battery; the top of the anode plate is provided with a first hydrogen inlet and a first air outlet, the bottom of the anode plate is provided with a first hydrogen outlet and a first air inlet, and the surface of the anode plate facing the membrane electrode is provided with a hydrogen guide groove; the top of negative plate is provided with second hydrogen import and second air outlet, and the bottom of negative plate is provided with second hydrogen export and second air inlet, and the negative plate is provided with the air guiding gutter on the surface towards membrane electrode.

Further, the hydrogen guide groove comprises a plurality of straight flow channels arranged along the longitudinal direction of the anode plate, or the hydrogen guide groove comprises a plurality of bent flow channels arranged along the longitudinal direction of the anode plate, or the hydrogen guide groove comprises a bent roundabout flow channel, and the turning positions of the bent roundabout flow channel are positioned at the left side and the right side of the anode plate; the air guide groove includes a plurality of straight flow passages arranged in the longitudinal direction of the cathode plate, or the air guide groove includes a plurality of curved flow passages arranged in the longitudinal direction of the cathode plate.

Furthermore, the fuel cell stack also comprises a first metal plate positioned on one side of the first insulating plate far away from the plurality of cells and a second metal plate positioned on the other side of the second insulating plate far away from the plurality of cells, and a connecting structure is arranged between the first metal plate and the second metal plate, so that the first insulating plate, the first current collecting plate, the plurality of cells, the second current collecting plate and the second insulating plate are clamped between the first metal plate and the second metal plate.

According to another aspect of the present invention, there is provided a fuel cell stack system including a fuel cell stack and a detection circuit connected to the fuel cell stack, the fuel cell stack being the fuel cell stack described above.

Further, a first current collecting plate of the fuel cell stack comprises a plurality of current collecting plates, a second current collecting plate of the fuel cell stack is of an integral structure, the detection circuit comprises a main circuit, a plurality of branches connected with the main circuit and a load arranged on the main circuit, a first end of the main circuit is connected with the second current collecting plate, a first end of each branch is connected with each current collecting plate in a one-to-one correspondence mode, a second end of each branch is connected with the main circuit, the fuel cell stack system further comprises a plurality of first sensors, and each branch is provided with a first sensor.

Further, the fuel cell stack system further includes a second sensor disposed on the main path.

By applying the technical scheme of the invention, the fuel cell stack comprises a first insulating plate, a first current collecting plate, a plurality of cells, a second current collecting plate and a second insulating plate which are sequentially arranged. The first current collecting plate is mounted on the first insulating plate, and the second current collecting plate is mounted on the second insulating plate. In the present application, the first current collecting plate and/or the second current collecting plate includes a plurality of current collecting sub-plates arranged at intervals, the plurality of current collecting sub-plates divide the fuel cell stack into a plurality of current collecting areas, and each current collecting sub-plate is capable of collecting current of each cell corresponding to the current collecting sub-plate. In this way, under the condition of detecting the performance of the fuel cell stack, each sub-current plate can monitor the actual reaction performance distribution, namely the current density, of the local area in the multi-section cells in real time through the equipotential sub-area current collection design. Therefore, the technical scheme of the application can solve the problems that in the prior art, the performance of the fuel cell can only be judged through the voltage of the whole cell stack or the voltage of each cell in the cell stack, and the specific performance distribution in the cell stack cannot be obtained in the judging process.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 shows an exploded schematic view of a prior art fuel cell stack structure;

FIG. 2 shows a schematic cross-sectional view of a bipolar plate of the fuel cell stack structure of FIG. 1;

FIG. 3 shows a schematic membrane electrode cross-sectional view of the fuel cell stack structure of FIG. 1;

FIG. 4 shows a schematic cross-sectional view of a single cell of the fuel cell stack structure of FIG. 1;

FIG. 5 shows a schematic diagram of the water-heat balance of the interior of the fuel cell stack structure of FIG. 1;

FIG. 6 shows a schematic cross-sectional view of a first embodiment of a fuel cell stack according to the present invention;

FIG. 7 shows a partially exploded schematic view of the fuel cell stack of FIG. 6;

FIG. 8 shows a schematic side view of the sub-current plate of the fuel cell stack of FIG. 6 mounted within a first insulating plate;

FIG. 9 shows a schematic side view of a first insulating plate of the fuel cell stack of FIG. 6;

FIG. 10 shows a schematic side view of a sub-current plate of the fuel cell stack of FIG. 6;

FIG. 11 shows a schematic side view of an anode plate of the fuel cell stack of FIG. 6;

FIG. 12 shows a schematic side view of the cathode plates of the fuel cell stack of FIG. 6;

figure 13 shows a schematic side view of an anode plate of a second embodiment of a fuel cell stack according to the invention;

FIG. 14 shows a schematic side view of the cathode plates of the fuel cell stack of FIG. 13;

figure 15 shows a schematic side view of an anode plate of a third embodiment of a fuel cell stack according to the present invention;

FIG. 16 shows a schematic side view of the cathode plates of the fuel cell stack of FIG. 15;

FIG. 17 is a partially exploded schematic view showing a fourth embodiment of a fuel cell stack according to the present invention;

FIG. 18 shows a partially exploded schematic view of an embodiment five of a fuel cell stack according to the present invention;

FIG. 19 shows a system diagram of an embodiment of a fuel cell stack system according to the invention;

FIG. 20 shows a schematic diagram of the water-heat balance of the interior of the fuel cell stack system of FIG. 19; and

figure 21 shows a schematic diagram of a current distribution of a fuel cell stack of the fuel cell stack system of figure 19.

Wherein the figures include the following reference numerals:

11. the fuel cell comprises a first insulating plate, a first embedded groove, a second embedded groove, a third insulating plate, a fourth insulating plate, a fifth insulating plate, a sixth insulating plate, a seventh insulating plate, a sixth insulating plate, a seventh plate, a sixth plate, a seventh plate, a sixth plate, a seventh plate, a sixth plate, a seventh plate.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

As shown in fig. 6 to 8, the fuel cell stack of the first embodiment includes a first insulating plate 11, a first current collecting plate C2, a plurality of cells a, a second current collecting plate C1, and a second insulating plate 15, which are sequentially disposed. The first current collecting plate C2 is mounted on the first insulating plate 11, and the second current collecting plate C1 is mounted on the second insulating plate 15, wherein the first current collecting plate C2 includes six current sub-collecting plates CC1, CC2, CC3, CC4, CC5, and CC6 arranged at intervals, and each current sub-collecting plate is capable of collecting current of a region corresponding to each cell a.

By applying the technical solution of the first embodiment, the first current collecting plate C2 includes six current collecting sub-plates CC1, CC2, CC3, CC4, CC5, and CC6 arranged at intervals, the six current collecting sub-plates CC1, CC2, CC3, CC4, CC5, and CC6 divide the fuel cell stack into six current collecting regions, and each current collecting sub-plate can collect the current of each cell a in the region corresponding to the current collecting sub-plate. In this way, when the performance of the fuel cell stack is detected, each sub-current plate can monitor the actual reaction performance distribution, i.e. the current density, of the local area inside the multiple cells a in real time through the equipotential sub-area current collecting design. Therefore, the technical scheme of the first embodiment can solve the problem that in the prior art, the performance of the fuel cell can only be judged by the voltage of the whole cell stack or by the voltage of each cell in the cell stack, and the specific performance distribution in the cell stack cannot be known in the judging process. Therefore, the technical scheme of the first embodiment can provide more sufficient and necessary real-time monitoring information for the integration and control scheme of the fuel cell power generation system and the engine, so that the operation condition and the control strategy of the stack are purposefully optimized, the output performance and the stability of the fuel cell are improved, and the service life decay rate of the fuel cell is greatly reduced.

In the first embodiment, the first current collecting plate C2 is an anode current collecting plate, and the second current collecting plate C1 is a cathode current collecting plate.

Six sub-flow plates are shown in fig. 6 and 7 as independent six sub-flow plates CC 1-CC 6. Of course, in other embodiments not shown in the drawings, the number of the sub-flow plates in the first embodiment is not limited to six, and the number may be two, three, four, five, or more than seven. In this way, increasing the number of sub-current plates can increase the resolution of the current distribution measurement, thereby giving finer local current details. Meanwhile, the number of the sub-current collecting plates is increased, the number of current monitoring channels is increased, the signal monitoring hardware requirement is increased, and the dynamic monitoring response frequency of multi-current signals is reduced. Therefore, the number of the sub-current plates can be designed according to the reaction area of the membrane electrode of the cell stack and the resolution requirement of current distribution measurement.

As shown in fig. 6 to 8, six sub-flow plates CC1, CC2, CC3, CC4, CC5, CC6 are parallel to each other, and six sub-flow plates CC1, CC2, CC3, CC4, CC5, CC6 are arranged from top to bottom. Thus, the six sub-flow plates CC1, CC2, CC3, CC4, CC5 and CC6 are independently arranged on the end faces of the plurality of cells a in one dimension. The arrangement mode is convenient for each sub-current collecting plate to collect the current of each cell A and the corresponding area of the sub-current collecting plate on one hand, and is convenient for each sub-current collecting plate to be connected with the detection circuit of the fuel cell stack on the other hand. The above-mentioned "from top to bottom" is the direction indicated by the arrow in fig. 6.

As shown in fig. 8 to 10, each of the sub-current plates includes terminals Co at the ends, which protrude from the first insulating plate 11. Therefore, the terminal Co can be directly connected with the detection circuit of the fuel cell stack, and the wiring is convenient. The terminal Co in the first embodiment protrudes from the right side of the first insulating plate 11, and of course, the terminal may protrude from the left side of the first insulating plate, and the terminal may be flexibly designed according to a specific connection mode when the specific terminal is connected to the detection circuit of the fuel cell stack.

As shown in fig. 8 to 10, six insertion grooves G for accommodating the plurality of sub-diversion plates CC1, CC2, CC3, CC4, CC5 and CC6 are formed on the first insulation plate 11, a first end of each insertion groove G is a closed end G1, and a second end of each insertion groove G is an open end G2. This facilitates the installation of the sub-manifold in the insertion groove G while the terminals Co protrude from the open end G2. Of course, the number of the insertion grooves may not be limited to six, and the number of the insertion grooves may be determined according to the number of the sub-manifold plates.

As shown in fig. 6, in the first embodiment, the plurality of cells a includes an anode end plate B1 and a cathode end plate B2 at both ends. The inside of anode end plate B1 contains the channels of the anode channels, and the outside of the end of anode end plate B1 can be selectively designed with a cooling fluid chamber similar to channel B5 in fig. 2. The cathode end plate B2 is a flow channel with cathode guiding groove on the inner side, and the cooling fluid cavity can be designed on the outer side of the end of the cathode end plate B2. The above-mentioned "inside" is a direction toward the center of the plurality of batteries a. The "outer side" is a direction away from the center of the plurality of batteries a. The above-described cooling fluid chamber facilitates the circulation of the cooling fluid within the plurality of batteries a.

As shown in fig. 6 and 8, a surface of each of the sub-current plates is coplanar with a surface of the first insulating plate 11 in a direction toward the plurality of cells a. In this way, each sub-current plate can be attached to the anode end plate B1 away from the plane of the plurality of cells a, so that each sub-current plate can smoothly collect current.

As shown in fig. 6, 8 to 12, each cell a includes an anode plate B1, a membrane electrode 20, and a cathode plate B2, which are arranged in this order. In two adjacent batteries A, the cathode plate B2 of one battery A is adjacent to the anode plate B1 of the other battery A. The top of the anode plate B1 is provided with a first hydrogen inlet 31 and a first air outlet 32, the bottom of the anode plate B1 is provided with a first air inlet 33 and a first hydrogen outlet 34, and the surface of the anode plate B1 facing the membrane electrode 20 is provided with a hydrogen guiding groove 35. The hydrogen gas guiding grooves 35 are arranged to form hydrogen gas flow channels on the anode plate B1, so as to facilitate the circulation of hydrogen gas. The top of the cathode plate B2 is provided with a second hydrogen inlet 41 and a second air outlet 42, the bottom of the cathode plate B2 is provided with a second air inlet 43 and a second hydrogen outlet 44, and the surface of the cathode plate B2 facing the membrane electrode 20 is provided with an air guiding groove 45. The air guiding grooves 45 are arranged to form an air flow channel on the cathode plate B2, so that air circulation is facilitated. The adjacent anode plate B1 and cathode plate B2 in the first embodiment are combined into a bipolar plate B.

As shown in fig. 11 and 12, in the first embodiment, the dotted area is a collecting area B7 corresponding to each sub-current plate.

In the first embodiment, the top of the anode plate B1 is further provided with a first water outlet 36, and the bottom of the anode plate B1 is further provided with a first water inlet 37. The top of the cathode plate B2 is also provided with a second water outlet 46, and the bottom of the cathode plate B2 is also provided with a second water inlet 47. The top of the first insulating plate 11 is provided with a third hydrogen inlet 51, a third air outlet 52 and a third water outlet 56, and the bottom of the first insulating plate 11 is provided with a third air inlet 53, a third hydrogen outlet 54 and a third water inlet 57.

In the first embodiment, each first hydrogen inlet 31, each second hydrogen inlet 41 and each third hydrogen inlet 51 are communicated with each other. Each first air outlet 32, each second air outlet 42 and each third air outlet 52 are interconnected. Each first air inlet 33, each second air inlet 43 and each third air inlet 53 communicate with each other. Each first hydrogen outlet 34, each second hydrogen outlet 44 and each third hydrogen outlet 54 are interconnected. Each first water outlet 36, each second water outlet 46 and each third water outlet 56 are communicated with each other. Each first water inlet 37, each second water inlet 47 and each third water inlet 57 are mutually through-going.

As shown in fig. 11 and 12, in the first embodiment, an anode reaction region B11 is formed on the anode plate B1, and a cathode reaction region B21 is formed on the cathode plate B2. The arrangement of six sub-manifold plates divides the plurality of cells a into six current collecting regions B7. The current generated after the reaction of anode reaction zone B11 and cathode reaction zone B21 is collected by six sub-current plates CC1, CC2, CC3, CC4, CC5 and CC 6. Hydrogen enters the hydrogen guiding groove 35 from the first hydrogen inlet 31, passes through the anode reaction area B11, and is discharged from the first hydrogen outlet 34. Air enters air guide channel 45 from second air inlet 43, passes through cathode reaction zone B21, and exits through second air outlet 42.

In the first embodiment, along the straight direction from the hydrogen inlet to the hydrogen outlet, the plurality of sub-diversion plates CC1, CC2, CC3, CC4, CC5 and CC6 divide the plurality of batteries a into a plurality of current collecting regions B7 in one dimension.

As shown in fig. 6, the fuel cell stack further includes a first metal plate 13 located on one side of the first insulating plate 11 away from the plurality of cells a and a second metal plate 14 located on the other side of the second insulating plate 15 away from the plurality of cells a, and a connection structure 16 is provided between the first metal plate 13 and the second metal plate 14, so that the first insulating plate 11, the first current collecting plate C2, the plurality of cells a, the second current collecting plate C1, and the second insulating plate 15 are sandwiched between the first metal plate 13 and the second metal plate 14. This secures the plurality of cells a to one body by the connection structure 16, and further, the overall structure of the fuel cell stack is stabilized. The connecting structure 16 of the first embodiment is preferably a pull rod and a nut.

As shown in fig. 6, the second current collecting plate C1 is a one-piece structure; the first metal plate 13 is an anode metal terminal plate, and the second metal plate 14 is a cathode metal terminal plate.

As shown in fig. 11 and 12, the hydrogen guide grooves 35 include meandering flow channels, and the turns of the meandering flow channels are located on the left and right sides of the anode plate B1, and the air guide grooves 45 include straight flow channels arranged in the longitudinal direction of the cathode plate B2. Thus, the design of the air guiding grooves 45 of the hydrogen guiding grooves 35 can be applied to the fuel cell stack for graphite plate vehicles of commercial vehicles in the traffic field. It should be noted that each of the current collecting regions B7 is designed to avoid flow channel bends across multiple anode flow fields.

As shown in fig. 13 and 14, in the second embodiment of the fuel cell stack of the present application, the difference from the first embodiment is in the shapes of the anode flow field and the cathode flow field. In the second embodiment, the hydrogen guiding groove 35 includes a plurality of straight flow channels arranged along the longitudinal direction of the anode plate B1. Air guide channel 45 includes a plurality of straight flow channels arranged in the longitudinal direction of cathode plate B2.

As shown in fig. 15 and 16, in the third embodiment of the fuel cell stack of the present application, the difference from the first embodiment is in the shapes of the anode flow field and the cathode flow field. In the third embodiment, the hydrogen guide grooves 35 include a plurality of meandering flow channels arranged in the longitudinal direction of the anode plate B1. Air guide groove 45 includes a plurality of meandering flow paths arranged in the longitudinal direction of cathode plate B2. The design of the air guiding groove 45 of the hydrogen guiding groove 35 in the third embodiment is suitable for fuel cell stacks for passenger cars and sheet metal cars in the transportation field.

As shown in fig. 17, the fourth embodiment of the fuel cell stack of the present application differs from the first embodiment in the structure of the first current collecting plate and the first insulating plate, and the structure of the second current collecting plate and the second insulating plate. In the fourth embodiment, the first current collecting plate C2 is an anode current collecting plate, and the second current collecting plate C1 is a cathode current collecting plate. The second current collecting plate is a monolithic structure, the second current collecting plate C1 comprises six current collecting sub-plates CC1, CC2, CC3, CC4, CC5 and CC6 which are arranged at intervals, the six current collecting sub-plates CC1, CC2, CC3, CC4, CC5 and CC6 divide the fuel cell stack into six current collecting areas, and each current collecting sub-plate can collect the current of each cell a in the area corresponding to the current collecting sub-plate. In this way, when the performance of the fuel cell stack is detected, each sub-current plate can monitor the actual reaction performance distribution, i.e. the current density, of the local area inside the multiple cells a in real time through the equipotential sub-area current collecting design. Therefore, the fourth technical solution of this embodiment can solve the problem that in the prior art, the performance of the fuel cell can only be determined by the voltage of the whole cell stack or by the voltage of each cell in the cell stack, and the specific performance distribution in the cell stack cannot be known in the determination process.

As shown in fig. 17, in the fourth embodiment, each of the sub-current plates includes the terminal Co at the end portion, and the terminal Co protrudes from the second insulating plate. The second insulating plate is formed with six insertion grooves for receiving six sub-current plates CC1, CC2, CC3, CC4, CC5, CC6, a first end of each insertion groove is a closed end, a second end of each insertion groove is an open end, and a terminal of each sub-current plate is protruded from the open end. Therefore, the terminal can be directly connected with the detection circuit of the fuel cell stack, and wiring is convenient.

As shown in fig. 18, in example five of the fuel cell stack of the present application, the first current collecting plate C2 is an anode current collecting plate, and the second current collecting plate C1 is a cathode current collecting plate. In the fifth embodiment, the first collecting plate C2 includes six sub-collecting plates CC1, CC2, CC3, CC4, CC5 and CC6 which are arranged at intervals. The second collecting plate C1 includes six sub-collecting plates CC7, CC8, CC9, CC10, CC11, CC12 arranged at intervals. The six sub-flow plates CC1, CC2, CC3, CC4, CC5 and CC6 and the six sub-flow plates CC7, CC8, CC9, CC10, CC11 and CC12 divide the fuel cell stack into six current collection areas, and each sub-flow plate can collect the current of each cell A and the area corresponding to the sub-flow plate. In this way, when the performance of the fuel cell stack is detected, each sub-current plate can monitor the actual reaction performance distribution, i.e. the current density, of the local area inside the multiple cells a in real time through the equipotential sub-area current collecting design. Therefore, the fifth technical scheme of this embodiment can solve the problem that in the prior art, the performance of the fuel cell can only be judged by the voltage of the whole cell stack or by the voltage of each cell in the cell stack, and the specific performance distribution in the cell stack cannot be known in the judgment process.

As shown in fig. 18, each sub current collecting plate CC includes terminals Co at the end, which protrude from the first insulating plate 11 or the second insulating plate 15. The first insulating plate 11 and the second insulating plate 15 are respectively formed with six insertion grooves for receiving six sub-current plates, a first end of each insertion groove being a closed end, a second end of each insertion groove being an open end, and a terminal of each sub-current plate protruding from the open end. Therefore, the terminal can be directly connected with the detection circuit of the fuel cell stack, and wiring is convenient.

As can be seen from fig. 7, 17 and 18, the fuel cell stack of the first embodiment of fig. 7 is divided into a plurality of current collecting regions only on the anode current collecting plate, the fuel cell stack of the fourth embodiment of fig. 17 is divided into a plurality of current collecting regions only on the cathode current collecting plate, and the fuel cell stack of the fifth embodiment of fig. 18 is divided into a plurality of current collecting regions on both the cathode current collecting plate and the anode current collecting plate. The first embodiment and the fourth embodiment are respectively divided and collected on one side of the fuel cell stack; in the fifth embodiment, the fuel cell stack is subjected to partitioned current collection on both sides of the cathode current collecting plate and the anode current collecting plate.

In the fifth embodiment, there may be a difference in the current collected by the cathode current collecting plate and the anode current collecting plate in the corresponding local current collecting region, for example, the current collected by the sub current collecting plate CC1 and the current collected by the sub current collecting plate CC7 are not necessarily identical. Providing support for control strategy optimization for a fuel cell stack, the following two analyses can be performed: firstly, comparing current distribution differences at two sides of a cathode current collecting plate and an anode current collecting plate, namely evaluating the inconsistency between the multiple batteries and two sides of the cathode current collecting plate and the anode current collecting plate through the current differences between corresponding parts of the current collecting plates CC 1-CC 6 and CC 7-CC 12; secondly, the current distribution among the corresponding sub-flow plates CC 1-CC 6 on the two sides of the cathode flow collecting plate and the anode flow collecting plate and the current distribution among the sub-flow plates CC 7-CC 12 are averaged to obtain more reliable current distribution information in the fuel cell stack, so that the accuracy of a control strategy is improved.

The present application also provides a fuel cell stack system, as shown in fig. 19 to 21, the fuel cell stack system of the present embodiment includes a fuel cell stack and a detection circuit connected to the fuel cell stack, and the fuel cell stack is the fuel cell stack described above. The fuel cell stack system of the embodiment can solve the problem that in the prior art, the performance of the fuel cell can only be judged through the voltage of the whole cell stack or through the voltage of each cell in the cell stack, and the specific performance distribution in the cell stack cannot be known in the judging process.

As shown in fig. 19 to 21, the first current collecting plate C2 of the fuel cell stack includes a plurality of sub-current collecting plates CC1, CC2, CC3, CC4, CC5, and CC6, and the second current collecting plate C1 of the fuel cell stack is an integrated structure, the sensing circuit includes a main circuit L1, a plurality of branches L2 connected to the main circuit L1, and a load L provided on the main circuit L1, a first end of the main circuit L1 is connected to the second current collecting plate C1, a first end of each branch L2 is connected to each sub-current collecting plate in one-to-one correspondence, a second end of each branch L2 is connected to the main circuit L1, and the fuel cell stack system further includes a plurality of first sensors S1, S2, S3, S4, S5, and S6, one first sensor is provided on each branch L2, and the integrated structure is an integrated structure.

As shown in fig. 19, specifically, the current in each branch L2 passes through the precision resistor to generate a voltage difference, so that the first sensors S1, S2, S3, S4, S5 and S6 can collect the voltage value in real time, and convert the collected current signal of each sub-current plate into a voltage signal that can be monitored and read in real time, thereby realizing real-time monitoring of the currents I1-I6 in six current collecting regions of the fuel cell stack, a-1 in fig. 19 is the first battery, a-N is the nth battery, the main circuit L1 is the conductive bus after the currents in each current collecting region are collected, the current sensor is generally a precision resistor with a constant value, and the resistance value is preferably 1 milliohm to 10 milliohms.

As shown in fig. 19, the fuel cell stack system further includes a second sensor S0, the second sensor S0 is disposed on the main circuit L1, the currents on the plurality of sub current plates are summed by the respective branches L2 to form a total current, and the second sensor S0 is a current sensor capable of detecting the total current.

As shown in fig. 19 and 20, and with reference to fig. 5, the multi-cell a of the fuel cell stack will eventually exhibit certain performance under various external operating conditions, as represented by the output voltage across the current I1-I6 in each branch L2, the fuel cell stack monitors the current distribution from the hydrogen inlet 31 to the hydrogen outlet 34 or from the air outlet 42 to the air inlet 43 in real time to obtain the reaction characteristics of different regions, so as to provide data support for optimizing the control strategy of the fuel cell stack.

FIG. 21 is a typical current distribution diagram for the low humidity condition of the air inlet on the cathode plate of this embodiment. In fig. 21, the horizontal axis CCn represents the number of the current collecting region, and the vertical axis In represents the current value of the current collecting region. In this embodiment, the reaction performance of each local current collecting region in the combustion cell stack is not completely uniform and may be very different.

Specifically, for the same loading current, if the humidity of the air inlet on the cathode plate is too low, the water content of the proton exchange membrane at the air inlet is lower, and the proton exchange membrane presents higher proton conduction internal resistance, so that the I6 is greatly reduced, and the current load of other current collecting areas is inevitably increased, so that the electrochemical reaction polarization of other current collecting areas is increased, and finally the overall output voltage of the combustion cell stack is reduced, the dry and wet areas in the membrane electrode are extremely inconsistent, and the performance and the service life of the combustion cell stack are reduced when the membrane electrode works under the condition for a long time; if the humidity of an air inlet on a cathode plate is too high and the working current is large, the water content of a proton exchange membrane in the combustion cell stack is high, the proton exchange membrane presents low proton conduction internal resistance, and the current performance of I6, I5 and the like is improved, however, the liquid water content of an air outlet and a current collecting region nearby the air outlet is greatly increased due to the accumulation of reaction produced water in current collecting regions of CC 1-CC 3 and the like, so that the liquid water accumulation cannot be timely eliminated, a local water flooding phenomenon is caused, the current performance of the local current collecting region is reduced and unstable, the integral output voltage of the combustion cell stack is reduced and cannot be kept stable, the liquid water content in a porous electrode of the combustion cell stack is blocked, and the performance of the combustion cell stack is unstable and the service life of the combustion cell stack is seriously reduced after the combustion cell.

In the description of the present invention, it is to be understood that the orientation or positional relationship indicated by the orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal" and "top, bottom", etc. are usually based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplicity of description, and in the case of not making a reverse description, these orientation words do not indicate and imply that the device or element being referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore, should not be considered as limiting the scope of the present invention; the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.

Spatially relative terms, such as "above … …," "above … …," "above … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial relationship to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

It should be noted that the terms "first", "second", and the like are used to define the components, and are only used for convenience of distinguishing the corresponding components, and the terms have no special meanings unless otherwise stated, and therefore, the scope of the present invention should not be construed as being limited.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (6)

1. A fuel cell stack system comprising a fuel cell stack and a detection circuit connected to the fuel cell stack,

the fuel cell stack system comprises a first insulating plate (11), a first current collecting plate (C2), a plurality of cells (A), a second current collecting plate (C1) and a second insulating plate (15), wherein the first current collecting plate (C2) is assembled on the first insulating plate (11), the second current collecting plate (C1) is assembled on the second insulating plate (15), the first current collecting plate (C2) comprises a plurality of sub-current plates which are arranged at intervals, and each sub-current plate can collect the current of each cell (A) in the area corresponding to the sub-current plate;

each of the sub-current plates includes terminals (Co) at ends thereof, the terminals (Co) protruding from the first insulating plate (11);

a plurality of insertion grooves (G) for accommodating a plurality of sub-current plates are formed on the first insulating plate (11), a first end of each insertion groove (G) is a closed end (G1), a second end of each insertion groove (G) is an open end (G2), and the terminals (Co) extend from the open end (G2);

the first current collecting plate (C2) of the fuel cell stack comprises a plurality of sub current collecting plates, the second current collecting plate (C1) of the fuel cell stack is of an integral structure, the detection circuit comprises a main circuit (L1), a plurality of branches (L2) connected with the main circuit (L1) and a load (L) arranged on the main circuit (L1), a first end of the main circuit (L1) is connected with the second current collecting plate (C1), a first end of each branch (L2) is connected with each sub current collecting plate in a one-to-one correspondence manner, a second end of each branch (L2) is connected with the main circuit (L1), the fuel cell stack system further comprises a plurality of first sensors, and one first sensor is arranged on each branch (L2);

the fuel cell stack system further includes a second sensor (S0), the second sensor (S0) being provided on the main road (L1).

2. The fuel cell stack system of claim 1, wherein a plurality of the sub-current plates are parallel to each other and arranged from top to bottom.

3. The fuel cell stack system according to claim 1, wherein a surface of each of the sub-current plates is coplanar with a surface of the first insulating plate (11) in a direction toward the plurality of cells (a).

4. The fuel cell stack system according to claim 1, wherein each of the cells (a) comprises an anode plate (B1), a membrane electrode (20), and a cathode plate (B2) arranged in this order; in two adjacent batteries (A), the cathode plate (B2) of one battery (A) is adjacent to the anode plate (B1) of the other battery (A);

a first hydrogen inlet (31) and a first air outlet (32) are arranged at the top of the anode plate (B1), a first air inlet (33) and a first hydrogen outlet (34) are arranged at the bottom of the anode plate (B1), and a hydrogen guide groove (35) is arranged on the surface of the anode plate (B1) facing the membrane electrode (20);

the top of the cathode plate (B2) is provided with a second hydrogen inlet (41) and a second air outlet (42), the bottom of the cathode plate (B2) is provided with a second air inlet (43) and a second hydrogen outlet (44), and the surface of the cathode plate (B2) facing the membrane electrode (20) is provided with an air guide groove (45).

5. The fuel cell stack system of claim 4,

the hydrogen guide groove (35) comprises a plurality of straight flow channels arranged along the longitudinal direction of the anode plate (B1), or the hydrogen guide groove (35) comprises a plurality of bent flow channels arranged along the longitudinal direction of the anode plate (B1), or the hydrogen guide groove (35) comprises a bent and circuitous flow channel, and the bends of the bent and circuitous flow channel are positioned at the left side and the right side of the anode plate (B1);

the air guide groove (45) includes a plurality of straight flow passages arranged in the longitudinal direction of the cathode plate (B2), or the air guide groove (45) includes a plurality of curved flow passages arranged in the longitudinal direction of the cathode plate (B2).

6. The fuel cell stack system according to claim 5, further comprising a first metal plate (13) located on one side of said first insulating plate (11) away from said plurality of cells (A) and a second metal plate (14) located on the other side of said second insulating plate (15) away from said plurality of cells (A), wherein a connecting structure (16) is provided between said first metal plate (13) and said second metal plate (14) so that said first insulating plate (11), said first current collecting plate (C2), said plurality of cells (A), said second current collecting plate (C1), said second insulating plate (15) are sandwiched between said first metal plate (13) and said second metal plate (14).

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