Fuel cell stack

Abstract

A fuel cell stack including a core, a housing, and a positioning element is provided. The interior of the housing accommodates the reactor core. The shell is provided with an air inlet end and an air outlet end, the air inlet end is used for supplying sweeping gas into the shell, and the air outlet end is used for discharging the sweeping gas from the interior of the shell. A positioning element is disposed between the core and the housing for positioning the core within the housing. The positioning element is provided with a flow guide channel, and the purging gas can penetrate through the positioning element through the flow guide channel. In this way, the purging gas can have a good purging effect.

Description

Technical Field

[0001] The present application relates to the field of fuel cells. Background Art

[0002] The fuel cell stack is the core of the fuel cell system. A fuel cell stack known to the inventors includes two end plates, an insulating plate, a current collecting plate, a series of stacked single cells and a packaging structure. The stack uses hydrogen and air as reactant gases to generate current through electrochemical reactions to provide electric driving force. In order to protect the stack and reduce the impact of external loads on the stack, the stack is usually encapsulated in a shell. The structural stability of the stack shell is not only affected by vibration and impact, but also by itself. In addition, for the safe operation of the stack, the negative pressure of the air compressor is usually used to discharge the hydrogen and condensate water accumulated in the shell.

[0003] Some externally positioned battery stack packaging structures (for example, US10673039B2, CN110931834A, and CN106450372B) have defects such as being unable to achieve sealing or insufficient sealing force, being unable to meet the protection level standards for automotive fuel cells, being difficult to ensure assembly tolerances, having poor parallelism of the two end plates, and having a lot of stack deformation.

[0004] Some separate stack packaging structures (e.g., CN213242620U, CN203659995U, and CN115275300A) suffer from assembly dimensional deviations, poor sealing, and failure to meet automotive fuel cell protection standards. In particular, during operation and vibration, the core is prone to collapse due to vibration, leading to leakage failures.

[0005] For fuel cell stacks that are stacked first and then packaged (for example, CN214898528U, CN115498235A, and CN115911487A), there is a cross-sealing problem due to the addition of sealing surfaces, which can easily lead to seal failure of the stack. The packaging shell, as the load-bearing component of the fuel cell, requires high strength of the packaging structure and high precision of the stack assembly. This will affect the performance of the fuel cell stack, cannot ensure the assembly tolerance during the stack assembly process, and is even not suitable for mass production.

[0006] For fuel cell stacks that are directly packaged on a press after compression (for example, CN112687935A, CN116247265A, CN116259814A, CN216311853U, CN216528984U, CN110098414A, and US20230031961A1), even if the integration of the fuel cell stack is greatly improved, the sealing reliability cannot be guaranteed due to the cross seal. Since the stack has no lateral restrictions, it is easy to cause the core to twist. In addition, there is no buffer structure in the height direction of the internal stack, and a constant load and uniform force cannot be applied at both ends, making it difficult to cope with the expansion and contraction problems caused by changes in the operating temperature of the stack.

[0007] For an integrated packaged fuel cell stack (e.g., CN111785999A), it is similar to the above-mentioned separate package structure and independent package structure. In this package structure, the large rebound force on the end plate side will cause the shell to deform. It is impossible to achieve good compression consistency in a single gas diffusion layer (GDL), which will lead to problems such as press-fit misalignment, hydrogen leakage, and low single cell voltage. The assembly process requires multiple installation auxiliary components, which makes it more difficult to achieve automated production. Therefore, requirements are put forward for assembly accuracy, shell strength and core consistency.

[0008] In summary, fuel cell stacks lack a packaging structure and a rapid assembly method that ensures high assembly precision between the core and the shell, strong vibration resistance of the components, good insulation protection, small size and light weight.

[0009] On the other hand, in fuel cell systems, the core typically requires a good seal to support and protect it from external dust, impurities, and water contamination, and to meet IP67 protection levels. However, during normal operation, small amounts of hydrogen leaking from the fuel cell stack can accumulate between the stack body and the outer casing, posing further safety concerns.

[0010] To ensure hydrogen safety, the packaging structure requires air purge inlets and outlets to expel hydrogen from the casing. However, during the air purge process, water vapor from the stack and the outside air can enter the fuel cell stack casing due to leakage from sealing materials and sealing interfaces, pressure differential diffusion, and other factors. Because the fuel cell stack casing is in direct contact with the external environment, when water vapor that leaks or diffuses out of the stack contacts the inner surface of the casing, it condenses because the temperature inside the casing is lower than the temperature of the water vapor itself. Furthermore, the barrier of the casing reduces the kinetic energy of the water vapor molecules, causing them to settle on the inner wall of the casing. The condensed liquid water molecules form a water film on the surface of the metal casing. When other electrically charged components within the stack conduct electricity to the casing through this water film, the stack's electrical insulation performance is significantly reduced, leading to the risk of short-circuit combustion between individual cells within the stack, accelerated corrosion, and impacting the reliability and service life of the fuel cell system.

[0011] In the existing technology, air purging inside the stack shell relies on multi-valve pressure difference, and secondly, uses purging devices and drainage channels to optimize the purging path to improve purging and drainage efficiency, or uses a water thermal management module to prevent the formation of condensed water or water film and improve insulation performance.

[0012] The first type (eg, CN215731830U, CN112421076A, and CN110993989A) has the disadvantage of a complex structure, which may result in reduced adaptability of the fuel cell structure, volume, and other mounting point arrangements.

[0013] The second type (for example, CN218414672U, CN110137537A, CN111785999A, CN113013446A, CN116259813A, CN212571054U, and CN216597654U) may have problems with air purge efficiency (blind spots, slow purge process, blocked purge outlet, long purge flow channel, etc.) and insulation effect (the influence of purge design direction and the difficulty of condensate / water film purge is not considered).

[0014] The disadvantage of the third type (e.g., CN117013031A, CN102035002B, and CN216389460U) is the effect of temperature on the hydrophobic coating (changes in the water contact angle lead to a deterioration in the hydrophobic effect), which increases the complexity and manufacturing difficulty of the module packaging and even poses a safety risk.

[0015] In summary, there is currently a lack of a fuel cell that can continuously ventilate and purge the inner shell, which can promptly discharge leaked hydrogen, water vapor and condensed water, avoid the accumulation of hydrogen, water vapor and condensed water in the shell, and ensure the hydrogen safety and insulation performance of the fuel cell stack. Utility Model Content

[0016] This application is made in view of the above-mentioned state of the prior art. The purpose of this application is to provide a fuel cell stack that can overcome or alleviate at least one of the disadvantages described in the above-mentioned background art.

[0017] In order to achieve the above objectives, this application adopts the following technical solutions.

[0018] The present application provides the following fuel cell stack, comprising: a core; a shell, which accommodates the core inside, the shell being provided with an air inlet end and an exhaust end, the air inlet end being used to supply a purge gas to the interior of the shell, and the exhaust end being used to discharge the purge gas from the interior of the shell; and a positioning element, which is arranged between the core and the shell and is used to position the core inside the shell, the positioning element being provided with a guide channel, and the purge gas can pass through the positioning element via the guide channel.

[0019] In an optional solution, in the flow direction of the purge gas, the area of ​​the flow cross section of the flow guide channel of at least one of the positioning elements first decreases and then increases.

[0020] In another optional solution, a closed channel surrounding the core is provided between the core and the shell, the guide channel forms a part of the closed channel, and the air inlet end is connected to the exhaust end via the closed channel.

[0021] In another optional scheme, the closed channel includes a first part and a second part, the first part is jointly defined by the first wall portion of the core and the shell, and the second part is jointly defined by the second wall portion of the core and the shell, and the first part and the second part have different flow cross-sectional areas.

[0022] In another optional solution, the first wall portion and the second wall portion are arranged opposite to each other.

[0023] In another optional solution, the air inlet end is provided on the first wall portion and / or the second wall portion.

[0024] In another optional solution, the air inlet end is arranged at the bottom of the shell, and the air outlet end is arranged at the top of the shell.

[0025] In another optional solution, the core includes an input channel for receiving hydrogen, and the exhaust end is arranged at a position of the shell corresponding to the input channel.

[0026] In another optional scheme, the shell includes a first air inlet end and a second air inlet end as the air inlet end, the first air inlet end is arranged at one end portion of the shell in the width direction, and the second air inlet end is arranged at the other end portion of the shell in the width direction opposite to the one end portion of the shell in the width direction, and / or the shell includes a first exhaust end and a second exhaust end as the exhaust ends, the first exhaust end is arranged at one end portion of the shell in the length direction, and the second exhaust end is arranged at the other end portion of the shell in the length direction opposite to the one end portion of the shell in the length direction.

[0027] In another optional solution, the core is configured to be integrally packaged in the casing and to be removed from the casing.

[0028] In another optional embodiment, the core includes a battery, a first battery end plate, a second battery end plate, and a fastening rod, wherein the fastening rod is connected to the first battery end plate and the second battery end plate so that the first battery end plate and the second battery end plate jointly clamp the battery.

[0029] In another optional scheme, the shell includes a separable bottom shell and a top shell, the bottom shell and the top shell are assembled into a thin-walled conformal structure, the core is encapsulated between the bottom shell and the top shell, and the core is stacked along the extension direction of the thin-walled conformal structure.

[0030] In another optional solution, the shell further includes a positioning pin, the bottom shell includes a first mounting hole, the top shell includes a second mounting hole, and the first mounting hole and the second mounting hole receive the positioning pin so that the bottom shell and the top shell are positioned relative to each other.

[0031] In another optional solution, the positioning pin is cylindrical, and the fastener screwed into the first mounting hole passes through the positioning pin.

[0032] In another optional solution, the second mounting hole is a waist-shaped hole.

[0033] In another optional solution, the bottom shell includes a first positioning surface, a second positioning surface and a third positioning surface that are orthogonal to each other, and the core abuts against the first positioning surface, the second positioning surface and the third positioning surface, so that the core and the bottom shell are positioned relative to each other.

[0034] In another optional solution, the core, the bottom shell and the top shell are provided with connection holes, and the connection holes receive fasteners so that the core, the bottom shell and the top shell are fixedly connected to each other.

[0035] In another optional solution, the shell further includes a first end plate and a second end plate, wherein the first end plate covers one end portion of the thin-walled conformal structure, and the second end plate covers the other end portion of the thin-walled conformal structure.

[0036] In another optional solution, the core includes an input interface and an output interface, and the first end plate is sleeved on the input interface and the output interface.

[0037] In another optional solution, a battery voltage inspection module is further included, which is connected to the core via an inspection harness. The second end plate is provided with a harness window, and the inspection harness passes through the second end plate via the harness window.

[0038] By adopting the above technical solution, by setting up a guide channel, the purge gas can pass through the positioning element via the guide channel, so that dead zones that are difficult for the purge gas to reach are less likely to appear in the shell, thereby improving the purge effect of the purge gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a schematic diagram of a fuel cell stack according to an embodiment of the present application, in which the first air inlet end and the second air inlet end are omitted.

[0040] Figure 2 yes Figure 1 Exploded view of the fuel cell stack in FIG, wherein the first air inlet end and the second air inlet end are omitted.

[0041] Figure 3 yes Figure 1 A partially enlarged view of the cross-sectional view of the fuel cell stack.

[0042] Figure 4 yes Figure 1 An exploded view of a portion of the structure of a fuel cell stack, wherein the first air inlet end and the second air inlet end are omitted.

[0043] Figure 5 yes Figure 1 An exploded view of another portion of the fuel cell stack structure, wherein the first exhaust port and the second exhaust port are omitted.

[0044] Figure 6 yes Figure 1 An exploded view of the partial structure of the fuel cell stack shell.

[0045] Figure 7 yes Figure 1 A cross-sectional view of a portion of the fuel cell stack structure.

[0046] Figure 8 yes Figure 1An exploded view of the core structure of a fuel cell stack.

[0047] Figure 9 yes Figure 1 A cross-sectional view of a fuel cell stack.

[0048] Figure 10 yes Figure 1 A cross-sectional view of a portion of the fuel cell stack structure.

[0049] Description of Reference Numerals

[0050] 30 fuel cell stack

[0051] 32 shell

[0052] 34 main housing

[0053] 36 auxiliary shell

[0054] 38 bottom shell

[0055] 40 top shell

[0056] 42 First end plate

[0057] 44 Second end plate

[0058] 46 First exhaust port

[0059] 48 Second exhaust port

[0060] 50 First exhaust valve

[0061] 52 Second exhaust valve

[0062] 54 Drain valve

[0063] 56 core

[0064] 58 Fastening rod

[0065] 60 positioning pin

[0066] 62 First mounting hole

[0067] 64 Second mounting hole

[0068] 66 First positioning element

[0069] 67 First positioning surface

[0070] 68 First convex part

[0071] 69 Second positioning surface

[0072] 70 First diversion channel

[0073] 71 Third positioning surface

[0074] 72 sump

[0075] 73 First connection block

[0076] 74 Drainage end

[0077] 75 First connection hole

[0078] 76 bottom wall

[0079] 77 Second connection block

[0080] 78 sidewall

[0081] 79 Third mounting hole

[0082] 80 Second positioning element

[0083] 81 Second connection hole

[0084] 82 Second convex part

[0085] 83 Third connection block

[0086] 84 Second diversion channel

[0087] 85 Fourth mounting hole

[0088] 86 Wiring Window

[0089] 87 Third connection hole

[0090] 88 batteries

[0091] 89 Fourth connection block

[0092] 90 First collector plate

[0093] 91 Fourth connection hole

[0094] 92 first insulating plate

[0095] 93 Sixth connecting hole

[0096] 94 First battery end plate

[0097] 95 Eighth connection hole

[0098] 96 Second collector plate

[0099] 97 Ninth connection hole

[0100] 98 Second insulation board

[0101] 99 Tenth connection hole

[0102] 100 compensation plate

[0103] 102 Second battery end plate

[0104] 104 Input Interface

[0105] 106 Output Interface

[0106] 108 seals

[0107] 110 First input channel

[0108] 112 Second input channel

[0109] 114 Third input channel

[0110] 116 First output channel

[0111] 118 Second output channel

[0112] 120 Third output channel

[0113] 122 Third positioning element

[0114] 124 Fourth positioning element

[0115] 126 The third diversion channel

[0116] 128 Fourth diversion channel

[0117] 130 bottom wall

[0118] 132 top wall

[0119] 134 sidewall

[0120] 136 sidewall

[0121] 138 Closed Channel

[0122] 140 Part 1

[0123] 142 Part 2

[0124] 144 First intake end

[0125] 146 Second intake port

[0126] L Length direction

[0127] W width direction

[0128] H height direction DETAILED DESCRIPTION

[0129] The following describes exemplary embodiments of the present application with reference to the accompanying drawings. It should be understood that these specific descriptions are only used to teach those skilled in the art how to implement the present application, and are not intended to exhaust all possible methods of the present application, nor to limit the scope of the present application.

[0130] Figure 1 is a schematic diagram of a fuel cell stack 30 according to one embodiment of the present application.

[0131] The fuel cell stack 30 may include a housing 32 . The housing 32 may include a main housing 34 and a sub-housing 36 . The sub-housing 36 may be fixedly mounted to the main housing 34 .

[0132] Figure 2 It is an exploded view of the fuel cell stack 30 .

[0133] The main housing 34 may include a bottom shell 38, a top shell 40, a first end plate 42, and a second end plate 44. The bottom shell 38 and the top shell 40 may be arranged in a height direction H (see FIG. Figure 1 ) are arranged opposite to each other, the first end plate 42 and the second end plate 44 can be arranged in the length direction L (see Figure 1 ) are arranged relative to each other on a vertical axis. Here, the height direction H can be a vertical direction, and the length direction L can be a horizontal direction. In a cross section perpendicular to the length direction L, the bottom shell 38 and the top shell 40 can have a generally U-shaped cross section. The bottom shell 38 can be disposed below the top shell 40, and the bottom shell 38 and the top shell 40 can be assembled together to form a generally square, thin-walled, conformable structure extending along the length direction L. The first end plate 42 can cover one end of the square tube, and the second end plate 44 can cover the other end of the square tube.

[0134] The housing 32 may be provided with a first exhaust port 46 and a second exhaust port 48. The first exhaust port 46 and the second exhaust port 48 may be provided on the top shell 40 and extend in the height direction H (see FIG. Figure 1 ) passes through the top shell 40. In the length direction L, the first exhaust end 46 can be set at one end of the shell 32, and the second exhaust end 48 can be set at the other end of the shell 32.

[0135] The fuel cell stack 30 may further include a first exhaust valve 50 and a second exhaust valve 52. The first exhaust valve 50 and the second exhaust valve 52 may be one-way valves. The first exhaust valve 50 may be connected to the first exhaust port 46, and the second exhaust valve 52 may be connected to the second exhaust port 48.

[0136] The fuel cell stack 30 may further include a drain valve 54 . The drain valve 54 may be an on-off valve and may be mounted on the bottom of the bottom case 38 .

[0137] The fuel cell stack 30 may further include a core 56, which may be enclosed within the main housing 34. The core 56 may include a plurality of fastening rods 58, which may enclose the core 56 in one piece.

[0138] It can be understood that by packaging the core 56 into one piece, the core 56 does not need to be compressed when placed in the casing 32, nor will it disintegrate when the casing 32 is removed, making the fuel cell stack 30 easy to install and maintain. In addition, the pre-packaged core 56 can eliminate the surrounding structure of the lower casing, such as in CN111785999A, so that the center of gravity of the fuel cell stack 30 can be roughly in the center, thereby facilitating a more balanced layout of the device (such as a vehicle) in which the fuel cell stack 30 is installed.

[0139] Figure 3 It is a partially enlarged view of a cross-sectional view of the fuel cell stack 30 .

[0140] The main shell 34 may further include a locating pin 60. The bottom shell 38 may be provided with a first mounting hole 62, for example, the first mounting hole 62 may be a blind hole with a step. The large diameter portion of the first mounting hole 62 may be a light hole, and the small diameter portion of the first mounting hole 62 may be a threaded hole. The top shell 40 may be provided with a second mounting hole 64, for example, the second mounting hole 64 may be a waist-shaped (oblong) through hole. A fastener (not shown) may pass through the second mounting hole 64 and screwed into the small diameter portion of the first mounting hole 62, so that the bottom shell 38 is fixedly connected to the top shell 40. The locating pin 60 may extend into the large diameter portion of the first mounting hole 62 and the second mounting hole 64, so that the bottom shell 38 and the top shell 40 can be positioned relative to each other by the locating pin 60. The locating pin 60 may be cylindrical, and the fastener may pass through the locating pin 60 via the hollow portion of the locating pin 60.

[0141] It can be understood that by providing the positioning pins 60 , the top shell 40 is easily positioned and mounted on the bottom shell 38 , and is easily detached from the bottom shell 38 , making the fuel cell stack 30 easy to assemble and maintain.

[0142] It can be understood that by making the second mounting hole 64 a waist-shaped hole, the positioning pin 60 can easily extend into the second mounting hole 64 and can move along the second mounting hole 64, thereby further reducing the difficulty of assembling and maintaining the fuel cell stack 30.

[0143] Figure 4 It is an exploded view of a portion of the structure of the fuel cell stack 30 .

[0144] The fuel cell stack 30 may further include a first positioning element 66 (an example of a positioning element). The inner wall surface of the bottom shell 38 may be provided with a plurality of first protrusions 68. The first positioning element 66 may be mounted to the inner side of the bottom shell 38 (the side facing the core 56) by receiving the first protrusions 68 through a structure such as a groove or a hole. The first positioning element 66 may be provided with a plurality of first guide channels 70 (an example of a guide channel). The first guide channel 70 may pass through the first positioning element 66 along the width direction W, and the plurality of first guide channels 70 may be arranged side by side in the length direction L. Here, the width direction W may be a horizontal direction orthogonal to the length direction L. The first positioning element 66 may be made of an insulating material, for example, may be made of a plastic with a low water absorption rate.

[0145] The inner wall surface of the bottom shell 38 may be provided with a plurality of water collecting grooves 72. The water collecting grooves 72 may be provided at the bottom of the bottom shell 38, and the first protrusion 68 may be provided between two adjacent water collecting grooves 72. The bottom of the water collecting groove 72 may be provided with a drainage end 74, and the water collecting groove 72 may be connected to the drainage valve 54 (see Figure 2 The bottom wall 76 and at least one side wall 78 of the sump 72 may have a certain slope to collect water flowing into the sump 72 to the drain end 74. For example, the two side walls 78 may be arranged opposite each other in the width direction W. Preferably, the slope angle of the bottom wall 76 may be 0.5° to 2.5°, and the slope angle of the side wall 78 may be 35° to 50°.

[0146] Furthermore, the inner wall surface of the housing 32 can have a relatively small roughness, so that water droplets have a relatively small contact angle on the inner wall surface, thereby preventing the formation of a water film on the inner wall surface of the housing 32 and ensuring the insulation performance of the fuel cell stack 30. In addition, even if a water film has formed on the inner wall surface of the housing 32, the water droplets attached to the inner wall surface can easily flow into the water collection groove 72 under the guidance of the inner wall surface, so that the insulation performance of the fuel cell stack 30 is quickly restored.

[0147] The number of the first mounting holes 62 can be multiple. For example, in this embodiment, the number of the first mounting holes 62 can be two, and the two first mounting holes 62 can be arranged diagonally, that is, the two first mounting holes 62 are spaced apart in both the length direction L and the width direction W. In this way, by arranging the two first mounting holes 62 diagonally, even if the main housing 34 (see Figure 1 ) is larger in size, the bottom shell 38 and the top shell 40 (see Figures 1 to 3 ) can still be positioned with a smaller number of positioning pins 60.

[0148] The bottom case 38 may also include a plurality of third mounting holes 79. These third mounting holes 79 may be threaded holes and are arranged side by side with the first mounting holes 62 in the length direction L. Compared to the first mounting holes 62, the third mounting holes 79 may be entirely threaded holes, without the stepped structure or the hollow portion. Fasteners (not shown) may be threaded into the third mounting holes 79, thereby securely connecting the bottom case 38 to the top case 40.

[0149] The bottom shell 38 may further include a plurality of first positioning surfaces 67, a plurality of second positioning surfaces 69, and a plurality of third positioning surfaces 71. The first positioning surfaces 67 may be perpendicular to the height direction H, and the two first positioning surfaces 67 may be spaced apart in the length direction L. Figure 2 ) can abut against the first positioning surface 67, so that the core 56 is positioned in the height direction H. The second positioning surface 69 can be perpendicular to the width direction W, and the two second positioning surfaces 69 can be arranged opposite each other in the width direction W. The core 56 can abut against the second positioning surface 69, so that the core 56 is positioned in the width direction W. The third positioning surface 71 can be perpendicular to the length direction L, and the two third positioning surfaces 71 can be arranged opposite each other in the length direction L. The core 56 can abut against the third positioning surface 71, so that the core 56 is positioned in the length direction L.

[0150] The bottom shell 38 may further include a plurality of first connection blocks 73. For example, two first connection blocks 73 may be spaced apart in the length direction L. The first connection blocks 73 may be provided with first connection holes 75 extending in the height direction H. Fasteners (not shown) mounted on the core 56 may be threaded into the first connection holes 75, thereby securely connecting the core 56 to the bottom shell 38. The first connection blocks 73 may provide the aforementioned third positioning surface 71. For example, a side surface of the first connection block 73 may serve as the third positioning surface 71.

[0151] The bottom shell 38 may further include a plurality of second connection blocks 77 . For example, two second connection blocks 77 may be spaced apart in the width direction W. The second connection blocks 77 may be provided with second connection holes 81 extending along the width direction W. Fasteners (not shown) mounted on the core 56 may be screwed into the second connection holes 81 to securely connect the core 56 to the bottom shell 38 .

[0152] Figure 5 It is an exploded view of another part of the structure of the fuel cell stack 30.

[0153] The fuel cell stack 30 may further include a second positioning element 80 (an example of a positioning element). The inner wall surface of the top shell 40 may be provided with a plurality of second protrusions 82. The second positioning element 80 may be mounted to the inner side of the top shell 40 (the side facing the core 56) by receiving the second protrusions 82 through a structure such as a groove or a hole. The second positioning element 80 may be provided with a plurality of second guide channels 84 (an example of a guide channel). The second guide channels 84 may pass through the second positioning element 80 in the width direction W, and the plurality of second guide channels 84 may be arranged side by side in the length direction L. The second positioning element 80 may be made of an insulating material, for example, may be made of a plastic with low water absorption.

[0154] The first positioning element 66 (see Figure 4 ) and the second positioning element 80 may be in the form of a strip plate, the dimension of which in the height direction H may be significantly smaller than the height of the core 56, and the length of which in the length direction L may be the same as that of the core 56 (see Figure 2 Here, the length direction L may be consistent with the stacking direction of (the plurality of cells of) the core 56.

[0155] The second mounting hole 64 may have a shape similar to that of the first mounting hole 62 (see Figure 3 and Figure 4 ) and are arranged at positions corresponding to the first mounting holes 62.

[0156] The top case 40 may further include a plurality of fourth mounting holes 85. The fourth mounting holes 85 may be circular through holes and arranged side by side with the second mounting holes 64 in the length direction L. The fourth mounting holes 85 may have a substantially equal spacing to the third mounting holes 79 (see FIG. Figure 4 ) and are arranged at positions corresponding to the third mounting holes 79. Fasteners (not shown in the figure) that are screwed into the third mounting holes 79 can pass through the fourth mounting holes 85.

[0157] The top shell 40 may further include a plurality of third connection blocks 83. For example, two third connection blocks 83 may be spaced apart in the length direction L. The third connection blocks 83 may be provided with third connection holes 87 extending in the height direction H. Fasteners (not shown) mounted on the core 56 may be screwed into the third connection holes 87, thereby securely connecting the core 56 to the top shell 40.

[0158] The top shell 40 may further include a plurality of fourth connection blocks 89. For example, two fourth connection blocks 89 may be spaced apart in the width direction W. The fourth connection blocks 89 may be provided with fourth connection holes 91 extending along the width direction W. Fasteners (not shown) mounted on the core 56 may be screwed into the fourth connection holes 91, thereby securely connecting the core 56 to the top shell 40.

[0159] Figure 6It is an exploded view of a part of the structure of the housing 32 .

[0160] The fuel cell stack 30 may also include a cell voltage monitor (CVM). The secondary housing 36 may be attached to the outside of the second end plate 44 (the side facing away from the stack core 56), and the CVM may be enclosed within the secondary housing 36. The CVM may be connected to the stack core 56 via a monitoring wiring harness, which may pass through the second end plate 44 via a wiring harness window 86 on the second end plate 44.

[0161] Figure 7 It is a cross-sectional view of a portion of the structure of the fuel cell stack 30 .

[0162] The core 56 may further include a battery 88, a first current collecting plate 90, a first insulating plate 92, a first battery end plate 94, a second current collecting plate 96, a second insulating plate 98, a compensating plate 100, and a second battery end plate 102 stacked together along the length direction L, that is, the stacking direction of the core 56 is parallel to the length direction L. The battery 88 may include a plurality of single batteries. The first current collecting plate 90, the first insulating plate 92, and the first battery end plate 94 may be disposed near the first end plate 42 (see FIG. Figure 2 ), a second current collecting plate 96, a second insulating plate 98, a compensating plate 100, and a second battery end plate 102 can be disposed on a side of the battery 88 near the second end plate 44. The first insulating plate 92 can be made of an insulating material and separates the first current collecting plate 90 from the first battery end plate 94. The second insulating plate 98 can be made of an insulating material and separates the second current collecting plate 96 from the compensating plate 100. The first battery end plate 94 and the second battery end plate 102 can serve as the two outermost ends of the core 56 and are connected via fastening rods 58 (see Figure 2 ) are fixedly connected to each other so that the first cell end plate 94 and the second cell end plate 102 can jointly clamp the portion of the core 56 located therebetween.

[0163] The first battery end plate 94 can be abutted against the first positioning surface 67 (see Figure 4 ), the second positioning surface 69 (see Figure 4 ) and the third positioning surface 71 (see Figure 4 ), the second cell end plate 102 can abut against the first positioning surface 67 and the third positioning surface 71 so that the core 56 is positioned in the main casing 34.

[0164] The first battery terminal plate 94 may be provided with a first connection hole 75 (see Figure 4 ) corresponding to the fifth connection hole and the third connection hole 87 (see Figure 5 ) corresponding to the sixth connecting hole 93 (see Figure 8The second battery end plate 102 may be provided with a seventh connection hole corresponding to the first connection hole 75 and an eighth connection hole 95 corresponding to the second connection hole 81 (see Figure 2 ), and the ninth connecting hole 97 corresponding to the third connecting hole 87 (see Figure 2 ) and the tenth connection hole 99 corresponding to the fourth connection hole 91 (see Figure 2 When the core 56 is positioned within the main casing 34 via the first positioning surface 67, the second positioning surface 69, and the third positioning surface 71, the corresponding connection holes can be substantially aligned with each other. Fasteners can be passed through the connection holes in the first cell end plate 94 or the second cell end plate 102 to be screwed into the connection holes in the main casing 34.

[0165] Figure 8 It is an exploded view of a portion of the structure of the core 56.

[0166] The first insulating plate 92 may include an input interface 104 and an output interface 106. The input interface 104 and the output interface 106 may extend through the first battery end plate 94 and the first end plate 42 (see Figure 2 ), and the ends of the input port 104 and the output port 106 may be substantially flush with the outer surface of the first end plate 42 (the surface facing away from the core 56). Here, the input port 104 may have multiple separate input channels, for example, three separate input channels, which are respectively connected to the first input channel 110, the second input channel 112, and the third input channel 114 described below. The output port 106 may have multiple separate output channels, for example, three separate output channels, which are respectively connected to the first output channel 116, the second output channel 118, and the third output channel 120 described below.

[0167] It can be understood that by inserting the input port 104 and the output port 106 into the first end plate 42 , the fuel cell stack 30 can have a shorter length, making the fuel cell stack 30 more compact.

[0168] The core 56 may also include two seals 108. The ends of the input port 104 and the output port 106 may be provided with mounting grooves, into which the two seals 108 may be respectively inserted. In this way, the input port 104 and the output port 106 may be sealedly connected to external piping via the seals 108.

[0169] Figure 9 It is a cross-sectional view of the fuel cell stack 30 .

[0170] The battery 88 may include a first input channel 110 (an example of an input channel), a second input channel 112, a third input channel 114, a first output channel 116, a second output channel 118, and a third output channel 120 extending along a length direction L. The first input channel 110, the second input channel 112, and the third input channel 114 may be connected to the input interface 104 (see FIG. Figure 8 ) is connected to the outside of the fuel cell stack 30, the first output channel 116, the second output channel 118 and the third output channel 120 can be connected to the fuel cell stack 30 via the output interface 106 (see Figure 8 ) is in communication with the outside of the fuel cell stack 30. The first input channel 110 is used to receive hydrogen, and the first output channel 116 is used to discharge hydrogen; the second input channel 112 is used to receive coolant, and the second output channel 118 is used to discharge coolant; the third input channel 114 is used to receive oxygen, and the third output channel 120 is used to discharge oxygen.

[0171] The fuel cell stack 30 may further include a third positioning element 122 (an example of a positioning element) and a fourth positioning element 124 (an example of a positioning element). The third positioning element 122 and the fourth positioning element 124 may be mounted on the core 56, for example, and may be fixedly connected to the core 56 by fasteners. The third positioning element 122 may be provided with a plurality of third flow guide channels 126 (an example of a flow guide channel). The third flow guide channel 126 may pass through the third positioning element 122 in the height direction H, and the plurality of third flow guide channels 126 may be arranged side by side in the length direction L. The fourth positioning element 124 may be provided with a plurality of fourth flow guide channels 128 (an example of a flow guide channel). The fourth flow guide channel 128 may pass through the fourth positioning element 124 in the height direction H, and the plurality of fourth flow guide channels 128 may be arranged side by side in the length direction L. The third positioning element 122 and the fourth positioning element 124 may be made of an insulating material, for example, may be made of a plastic with low water absorption. The first positioning element 66 and the second positioning element 80 can position the core 56 within the main casing 34 in the height direction H. The first positioning element 66 and the second positioning element 80 can be arranged opposite to each other in the height direction H. The first positioning element 66 can be disposed between the bottom wall 130 of the main casing 34 and the core 56, and abut against the core 56. The second positioning element 80 can be disposed between the top wall 132 of the main casing 34 and the core 56, and abut against the core 56. Here, the bottom wall 130 and the top wall 132 can be arranged opposite to each other in the height direction H, the bottom wall 130 can be formed separately from the bottom casing 38, and the top wall 132 can be formed separately from the top casing 40.

[0172] The third positioning element 122 and the fourth positioning element 124 can position the core 56 within the main casing 34 in the width direction W. The third positioning element 122 and the fourth positioning element 124 can be arranged opposite to each other in the width direction W. The third positioning element 122 can be disposed between a side wall 134 (an example of a first wall portion) of the main casing 34 and the core 56, and abut against the side wall 134. The fourth positioning element 124 can be disposed between a side wall 136 (an example of a second wall portion) of the main casing 34 and the core 56, and abut against the side wall 136. Here, the side wall 134 and the side wall 136 can be arranged opposite to each other in the width direction W and are jointly constituted by the bottom casing 38 and the top casing 40.

[0173] The third positioning element 122 and the fourth positioning element 124 may be in the shape of strips, and their dimensions in the width direction W may be significantly smaller than the width of the core 56 , and their lengths in the length direction L may be comparable to the length of the core 56 .

[0174] It will be appreciated that by providing the first positioning element 66, the second positioning element 80, the third positioning element 122, and the fourth positioning element 124, the main casing 34 can be supported by these positioning elements, thereby being less likely to deform (e.g., sag inward). Furthermore, under vibration conditions, these positioning elements can effectively limit the misalignment of the core 56, allowing the core 56 to remain in the correct position.

[0175] It can be understood that by making the first positioning element 66, the second positioning element 80, the third positioning element 122 and the fourth positioning element 124 from plastic with a low water absorption rate, the first positioning element 66, the second positioning element 80, the third positioning element 122 and the fourth positioning element 124 will only expand slightly after contacting water or water vapor, so that the third positioning element 122 and the fourth positioning element 124 will not excessively squeeze the core 56 due to expansion, thereby preventing damage to the core 56.

[0176] The fuel cell stack 30 may also be provided with a closed channel 138 for the purge gas to flow. The closed channel 138 may be provided between the main housing 34 and the stack core 56 and may be closed around the stack core 56. In other words, the closed channel 138 may extend into a substantially square ring shape. The closed channel 138 may be provided via the first exhaust port 46 (see FIG. Figure 2 ) and the first exhaust valve 50 (see Figure 2 ) is connected and can be exhausted via the second exhaust port 48 (see Figure 2 ) and the second exhaust valve 52 (see Figure 2 When the purge gas flows along the closed channel 138 , the purge gas may carry hydrogen leaked from the core 56 and be discharged from the casing 32 through the first exhaust port 46 and the second exhaust port 48 together with the hydrogen.

[0177] The first flow guiding channel 70, the second flow guiding channel 84, the third flow guiding channel 126, and the fourth flow guiding channel 128 can serve as part of the closed channel 138. In the flow direction of the purge gas, the flow cross-section areas of the first flow guiding channel 70 and the second flow guiding channel 84 can first gradually decrease and then gradually increase, while the flow cross-section areas of the third flow guiding channel 126 and the fourth flow guiding channel 128 can remain unchanged.

[0178] In other embodiments, in the flow direction of the purge gas, the flow cross-section areas of the third flow guiding channel 126 and the fourth flow guiding channel 128 may also first decrease and then increase.

[0179] It can be understood that by setting up the guide channels 70, 84, 126, and 128, the purge gas can pass through the positioning elements 66, 80, 122, and 124 via the guide channels 70, 84, 126, and 128, so that dead areas that are difficult for the purge gas to reach are less likely to appear in the shell 32, thereby improving the purge effect of the purge gas.

[0180] It can be understood that by first reducing and then increasing the flow cross-section area of ​​the flow guide channels 70 and 84 , the flow guide channels 70 and 84 can increase the flow rate of the purge gas, thereby further improving the purge effect of the purge gas.

[0181] It can be understood that by providing the closed channel 138 , the purge gas can flow around the core 56 , making it less likely that a dead zone will appear in the shell 32 , thereby further improving the purge effect of the purge gas.

[0182] Closed channel 138 may include a first portion 140 and a second portion 142. First portion 140 may be defined by sidewall 134 and core 56, while second portion 142 may be defined by sidewall 136 and core 56. In width direction W, the thickness of third positioning element 122 may be smaller than the thickness of fourth positioning element 124, such that core 56 is positioned closer to sidewall 134 between sidewalls 134 and 136. Accordingly, in this configuration, the flow cross-section of first portion 140 may be smaller than the flow cross-section of second portion 142.

[0183] In other embodiments, the first portion 140 is not limited to being defined by the side wall 134, and the second portion 142 is not limited to being defined by the side wall 136. For example, the first portion 140 may be defined by one of the bottom wall 130 and the top wall 132, and the second portion 142 may be defined by the other of the bottom wall 130 and the top wall 132. In other embodiments, the first portion 140 and the second portion 142 are not limited to being defined by two opposing walls of the housing 32, and may be defined by two adjacent walls of the housing 32, for example.

[0184] It is understood that by providing the first portion 140 and the second portion 142, the first portion 140 can form a low-pressure area within the closed channel 138, while the second portion 142 can form a high-pressure area within the closed channel 138, thereby creating a pressure differential within the closed channel 138. Driven by the pressure differential, the purge gas can have a higher flow rate, thereby further improving the purge effect.

[0185] It can be understood that by defining the first portion 140 and the second portion 142 by two opposing walls (side walls 134 and 136), the low-pressure area and the high-pressure area within the closed channel 138 can be separated as much as possible, so that the pressure gradient within the closed channel 138 can be more evenly distributed. In this way, the purge gas is less likely to be retained in the housing 32, thereby further improving the purge effect.

[0186] Figure 10 3 is a cross-sectional view of a portion of the structure of the fuel cell stack 30 , wherein the cutting plane of the cross-sectional view is perpendicular to the longitudinal direction L.

[0187] The housing 32 may be provided with a first air inlet port 144 and a second air inlet port 146. The first air inlet port 144 may be provided at a portion of the side wall 134 formed by the bottom shell 38 and pass through the side wall 134 in the width direction W. The second air inlet port 146 may be provided at a portion of the side wall 136 formed by the bottom shell 38 and pass through the side wall 136 in the width direction W. The first air inlet port 144 and the second air inlet port 146 may be arranged opposite to each other in the width direction W and located at the bottom of the housing 32. The first air inlet port 144 and the second air inlet port 146 may be connected to the first exhaust port 46 (see FIG. 1 ) via the closed passage 138. Figure 2 ) is connected to the second exhaust port 48, and the purge gas can be supplied to the closed channel 138 via the first intake port 144 and the second intake port 146.

[0188] In other embodiments, the first air inlet end 144 and the second air inlet end 146 may also be disposed on the bottom wall 130 .

[0189] It can be understood that by setting the air inlet ends 144 and 146 on the side walls 134 and 136, the purge gas entering the shell 32 can be preferentially filled into the first part 140 and the second part 142, so that the pressure difference in the closed channel 138 can be more easily established, thereby further improving the purge effect.

[0190] It can be understood that by arranging the exhaust ports 46 , 48 at the top of the shell 32 , hydrogen having a density lower than that of air can rise to the top of the shell 32 along the height direction H, thereby facilitating the discharge of hydrogen from the exhaust ports 46 , 48 .

[0191] It can be understood that by setting the first air inlet end 144 at one end of the shell 32 in the width direction and setting the second air inlet end 146 at the other end of the opposite width direction, the purge gas can easily fill the entire width of the shell 32, making it less likely for dead zones to appear in the shell 32, thereby further improving the purge effect of the purge gas.

[0192] It can be understood that by setting the first exhaust end 46 at one end of the shell 32 in the length direction and setting the second exhaust end 48 at the other end of the opposite length direction, the purge gas can easily fill the entire length of the shell 32, making it less likely for dead zones to appear in the shell 32, thereby further improving the purge effect of the purge gas.

[0193] It can be understood that by arranging the air inlet ends 144 and 146 along the width direction W and arranging the exhaust ends 46 and 48 along the length direction L, the purge gas can easily fill the entire width and length of the shell 32, thereby further improving the purge effect.

[0194] The first exhaust port 46 and the second exhaust port 48 may be disposed adjacent to the first input channel 110 (see Figure 9 ) corresponding to the position. The first input channel 110 can be disposed at the top of the core 56 in the height direction H and at one end of the core 56 near the sidewall 136 in the width direction W. Accordingly, the first exhaust port 46 and the second exhaust port 48 can be disposed at the top of the casing 32 in the height direction H and at one end of the casing 32 near the sidewall 136 in the width direction W.

[0195] It is understood that since first input channel 110 is used to receive hydrogen, hydrogen is more likely to leak from locations near first input channel 110. Therefore, compared to other locations, the concentration of leaked hydrogen is higher near first input channel 110. By locating exhaust ports 46 and 48 at locations corresponding to first input channel 110, exhaust ports 46 and 48 can be closer to locations with higher hydrogen concentrations, thereby further facilitating hydrogen discharge from exhaust ports 46 and 48.

[0196] The following combination Figures 1 to 10 The packaging method of the fuel cell stack 30 is introduced. The packaging method may include the following steps.

[0197] (i) Arranging and compressing the battery 88, the first current collecting plate 90, the first insulating plate 92, the first battery end plate 94, the second current collecting plate 96, the second insulating plate 98, the compensating plate 100, and the second battery end plate 102 on a pressing platform.

[0198] (ii) The compressed cells 88 , the first current collecting plate 90 , the first insulating plate 92 , the first cell end plate 94 , the second current collecting plate 96 , the second insulating plate 98 , the compensating plate 100 , and the second cell end plate 102 are packaged into a core 56 by fastening rods 58 .

[0199] (iii) Install the first positioning element 66 and the seal to the bottom housing 38 .

[0200] (iv) Mounting the second positioning element 80 and the seal to the top case 40 .

[0201] (v) Installing the third positioning element 122 and the fourth positioning element 124 to the core 56 .

[0202] (vi) The core 56 is roughly positioned within the bottom casing 38 by the first positioning surface 67 , the second positioning surface 69 , and the third positioning surface 71 .

[0203] (vii) The top shell 40 is placed on the bottom shell 38 , and the core 56 is precisely positioned between the bottom shell 38 and the top shell 40 by using the positioning pins 60 , the first connection holes 75 , the second connection holes 81 , and the third connection holes 87 .

[0204] (viii) The first end plate 42 and the second end plate 44 are mounted to the bottom shell 38 and the top shell 40 to form the main housing 34 .

[0205] (ix) Place the battery voltage inspection module in the auxiliary housing 36 and electrically connect the battery voltage inspection module to the stack core 56 .

[0206] (x) Mount the auxiliary housing 36 to the second end plate 44 .

[0207] (xi) Install the first exhaust valve 50 and the second exhaust valve 52 to the top case 40 .

[0208] (xii) Install the drain valve 54 to the bottom case 38 .

[0209] It is understood that the order of the above steps is exemplary and not restrictive, and the order of at least some of the steps may be adjusted or changed.

[0210] It should be understood that the above embodiments are merely exemplary and are not intended to limit the present application. Those skilled in the art may make various modifications and changes to the above embodiments based on the teachings of the present application without departing from the scope of the present application.

Claims

1. A fuel cell stack, characterized in that: include: core; a casing, the core being housed therein, the casing being provided with an air inlet and an air outlet, the air inlet being used to supply a purge gas into the interior of the casing, the air outlet being used to discharge the purge gas from the interior of the casing; as well as A positioning element is provided between the core and the shell and is used to position the core in the shell. The positioning element is provided with a guide channel, and the purge gas can pass through the positioning element via the guide channel.

2. The fuel cell stack according to claim 1, characterized in that: In the flow direction of the purge gas, the area of ​​the flow cross section of the flow guide channel of at least one of the positioning elements first decreases and then increases.

3. The fuel cell stack according to claim 1, characterized in that: A closed channel surrounding the core is provided between the core and the shell, the guide channel forms a part of the closed channel, and the air inlet end is communicated with the exhaust end via the closed channel.

4. The fuel cell stack according to claim 3, characterized in that: The closed channel includes a first part and a second part, the first part is jointly defined by the core and the first wall of the shell, and the second part is jointly defined by the core and the second wall of the shell, and the first part and the second part have different flow cross-sectional areas.

5. The fuel cell stack according to claim 4, characterized in that: The first wall portion and the second wall portion are arranged opposite to each other.

6. The fuel cell stack according to claim 4, characterized in that: The air inlet end is provided on the first wall portion and / or the second wall portion.

7. The fuel cell stack according to any one of claims 1 to 6, characterized in that: The air inlet end is arranged at the bottom of the shell, and the air outlet end is arranged at the top of the shell.

8. The fuel cell stack according to any one of claims 1 to 6, characterized in that: The core includes an input channel for receiving hydrogen, and the exhaust end is arranged at a position of the shell corresponding to the input channel.

9. The fuel cell stack according to any one of claims 1 to 6, characterized in that: The housing includes a first air inlet end and a second air inlet end as the air inlet ends, the first air inlet end being arranged at one end portion in the width direction of the housing, the second air inlet end being arranged at the other end portion in the width direction of the housing opposite to the one end portion in the width direction, and / or The shell includes a first exhaust end and a second exhaust end as the exhaust ends. The first exhaust end is arranged at one end portion of the shell in the longitudinal direction, and the second exhaust end is arranged at the other end portion of the shell in the longitudinal direction opposite to the one end portion in the longitudinal direction.

10. The fuel cell stack according to claim 1, characterized in that: The core is configured to be integrally packaged in the casing and to be removed from the casing.

11. The fuel cell stack according to claim 10, characterized in that: The core includes a battery, a first battery end plate, a second battery end plate, and a fastening rod connected to the first battery end plate and the second battery end plate so that the first battery end plate and the second battery end plate jointly clamp the battery.

12. The fuel cell stack according to claim 10, characterized in that: The shell includes a separable bottom shell and a top shell, the bottom shell and the top shell are assembled into a thin-walled conformal structure, the core is encapsulated between the bottom shell and the top shell, and the core is stacked along the extension direction of the thin-walled conformal structure.

13. The fuel cell stack according to claim 12, characterized in that: The housing further comprises a positioning pin, The bottom case includes a first mounting hole, and the top case includes a second mounting hole. The first mounting hole and the second mounting hole receive the positioning pin so that the bottom case and the top case are positioned relative to each other.

14. The fuel cell stack according to claim 13, characterized in that: The positioning pin is cylindrical, and a fastener screwed into the first mounting hole passes through the positioning pin.

15. The fuel cell stack according to claim 14, characterized in that: The second mounting hole is a waist-shaped hole.

16. The fuel cell stack according to claim 12, characterized in that: The bottom shell includes a first positioning surface, a second positioning surface, and a third positioning surface that are orthogonal to each other. The core abuts against the first positioning surface, the second positioning surface, and the third positioning surface, so that the core and the bottom shell are positioned relative to each other.

17. The fuel cell stack according to claim 12, characterized in that: The core, the bottom shell, and the top shell are provided with connection holes, and the connection holes receive fasteners so that the core, the bottom shell, and the top shell are fixedly connected to each other.

18. The fuel cell stack according to claim 12, characterized in that: The shell further includes a first end plate and a second end plate, wherein the first end plate covers one end portion of the thin-walled conformal structure, and the second end plate covers the other end portion of the thin-walled conformal structure.

19. The fuel cell stack according to claim 18, characterized in that: The core includes an input interface and an output interface, and the first end plate is sleeved on the input interface and the output interface.

20. The fuel cell stack according to claim 18, characterized in that: It also includes a battery voltage inspection module, which is connected to the core via an inspection harness. The second end plate is provided with a harness window, and the inspection harness passes through the second end plate via the harness window.

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