End plate assembly of a fuel cell stack and rapid encapsulation method

Abstract

The present invention relates to an end plate assembly and a rapid encapsulation method for a fuel cell stack. The end plate assembly includes a rear end plate (1), a bolt top plate (2), and an adjusting nut (3). The rear end plate (1) is connected to a housing (4). A coaxial through hole (11) and a counterbore (12) are provided on the rear end plate (1). The adjusting nut (3) is assembled in the through hole (11) and the counterbore (12). One end of the bolt top plate (2) is threadedly connected to the adjusting nut (3), and the other end is used to apply a pressing force to the stack core (5) inside the housing (4). Compared with the prior art, the present invention significantly reduces the number of parts and the assembly working hours of the module, overcomes the creep relaxation of each component of the fuel cell stack after experiencing actual harsh working conditions or long-term operation, resulting in performance attenuation of the fuel cell stack. The repair method is simple and convenient to operate, and the maintainability under vehicle-mounted conditions is strong. It can achieve convenient adjustment of the encapsulation load force and maintenance of the fuel cell stack throughout its life cycle.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and particularly relates to an end plate assembly and a rapid encapsulation method for a fuel cell stack. Background Art

[0002] A fuel cell is a method for hydrogen energy utilization and has currently been widely applied in fields such as vehicle power systems, fixed standby power supplies, and ship power supply and power systems, etc. Among them, a proton exchange membrane fuel cell (PEMFC) is a relatively mature technology that can release electrical energy through an electrochemical reaction between hydrogen and air. In practical applications, the core of a fuel cell stack usually needs to be composed of multiple single cells connected in series to meet the output power requirements. However, since single cells are expensive and fragile, multiple end plates and related fastening structures are required to support the structure of the stack, and at the same time, a sturdy shell with an IP sealing grade is needed to modularly integrate and protect the stack, enabling it to be installable in large transport vehicles and ships and power generation equipment, and ensuring the long-term reliable operation of the fuel cell under harsh working environments.

[0003] Chinese Patent CN 105609860A discloses a fuel cell module of Toyota Motor Corporation. In order to restore the attenuation of the core pressing force caused by the deformation of the fuel cell shell after long-term operation, a plurality of small pins are designed between the rear end plate and the shell, which are used for adjusting the restoration of the pressing force of the core during actual operation. At the same time, three other through holes are designed on the shell to meet the assembly requirements of the fuel cell stack core and the shell. Although the number of components is optimized compared with the traditional structure, the assembly holes and adjustment holes in this invention are separated, making the device extremely large and complex. Summary of the Invention

[0004] The purpose of the present invention is to provide an end plate assembly and a rapid encapsulation method for a fuel cell stack, reducing the number of parts and assembly man-hours of the module.

[0005] The purpose of the present invention can be achieved through the following technical solutions: An end plate assembly for a fuel cell stack includes a rear end plate, a bolt top plate, and an adjusting nut; the rear end plate is connected to the shell, and a coaxial through hole and a counterbore are provided on the rear end plate. The adjusting nut is assembled in the through hole and the counterbore. One end of the bolt top plate is threadedly connected to the adjusting nut, and the other end is used to apply a pressing force to the core inside the shell.

[0006] Preferably, the rear end plate is one side of the encapsulation shell and is connected to the shell in a fixed or detachable manner.

[0007] More preferably, the rear end plate is connected to other surfaces of the shell by means of threading, welding, riveting, tight fitting, or gluing, etc.

[0008] Further preferably, one end of the housing is encapsulated by a rear end plate, and the other end is encapsulated by a front end plate.

[0009] Preferably, the bolt top plate includes a top plate stud and a top plate. The top plate stud is threadedly connected to the adjusting nut, and the top plate is used to apply a pressing force to the reactor core.

[0010] Preferably, a floating end plate is provided between the bolt top plate and the reactor core.

[0011] Preferably, a threaded through hole is provided in the adjusting nut.

[0012] Preferably, the adjusting nut includes a main body portion and a flange plane. The main body portion corresponds to the through hole, and the flange plane corresponds to the counterbore.

[0013] Preferably, the diameter of the counterbore is larger than that of the through hole.

[0014] A rapid encapsulation method is carried out by using the end plate assembly of the above fuel cell stack.

[0015] Preferably, the rapid encapsulation method includes the following steps:

[0016] S1: Place the front end plate, the reactor core, and the floating end plate into the housing in sequence;

[0017] S2: Install the rear end plate, and then apply pressure to the rear end plate so that the rear end plate can be attached to and connected with the housing;

[0018] S3: Press-fit between the top plate on the reactor core side of the bolt top plate and the reactor core, and limit the floating end plate at the reactor core end through the bolt top plate, so as to provide the pressing force required for the normal operation of multiple single cells in the fuel cell stack;

[0019] S4: Rotate the adjusting nut backward until it is in close contact with the bottom of the counterbore of the rear end plate, and then remove the pressure.

[0020] The existing fuel cell stack packaging methods have disadvantages such as a large number of components, heavy weight, and high assembly costs, and it is difficult to meet the increasing requirements of fuel cell power systems or power generation equipment for high integration, high power, high power density, long life, and performance repairability of the stack. The present invention significantly reduces the number of parts and assembly man-hours of the module, overcomes the creep relaxation of each component after the stack experiences actual harsh working conditions or long-term operation, resulting in performance degradation of the stack. The repair method is simple and convenient to operate, and the maintainability in vehicle-mounted situations is strong. It can achieve convenient adjustment of the packaging load force and maintenance of the stack throughout its life cycle. The present invention reduces the types of key structural components, improves the integration of the module packaging housing, realizes the miniaturization and lightweight of the module-level fuel cell, effectively reduces costs, and is conducive to meeting the market demands of high power and heavy loads of fuel cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a sectional view of the stack packaging structure of the present invention;

[0022] Figure 2 is a sectional view of the assembly relationship of each part in the end plate assembly of the present invention;

[0023] Figure 3 is the assembly method of the stack module of the present invention;

[0024] In the figure: 1 - rear end plate, 11 - through hole, 12 - counterbore, 2 - bolt top plate, 21 - top plate stud, 22 - top plate, 3 - adjusting nut, 31 - threaded through hole, 32 - main body part, 33 - flange plane, 4 - housing, 5 - stack core, 6 - front end plate, 7 - floating end plate, 8 - single cell. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The following embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation manners and specific operation processes are given, but the protection scope of the present invention is not limited to the following embodiments.

[0026] Embodiment 1

[0027] An end plate assembly of a fuel cell stack, as Figure 1As shown in the figure, it at least includes a rear end plate 1, a bolt top plate 2 and an adjusting nut 3, where: The rear end plate 1 is one side of the encapsulation housing 4, and is connected to other sides of the housing 4 by means of threading, welding, riveting, tight fitting, or gluing, etc.; The rear end plate 1 at least includes a through hole 11 and a counterbore 12 coaxial with it; One end of the bolt top plate 2 is a flat surface (top plate 22) connected to the relevant structural components on the core side for applying a pressing force to the core 5, and the other end is composed of a stud (top plate stud 21) connected to the threaded through hole 31 provided in the center of the adjusting nut 3 to form a mutually supporting stress relationship; The adjusting nut 3 is assembled with and interacts with the counterbore 12 of the rear end plate 1 for transmitting the pressing force applied to the stack; The threaded connection between the adjusting nut 3 and the bolt top plate 2 bears all the pressing forces of the stack core. After the stack core has been operating for a long time, the structure can be pressed and tightened online through a tooling so that the stack core maintains a reasonable pressing force, thereby restoring its performance to a certain extent.

[0028] Embodiment 2

[0029] For an end plate assembly of a fuel cell stack, the adjusting nut 3 includes a main body portion 32 and a flange plane 33. The main body portion 32 corresponds to the through hole 11, and the flange plane 33 corresponds to the counterbore 12. The diameter of the counterbore 12 is larger than that of the through hole 11. The threaded through hole 31 is provided through the center of the main body portion 32 and the flange plane 33 and is threadedly connected to the top plate stud 21. The rest is the same as in Embodiment 1.

[0030] Embodiment 3

[0031] A rapid encapsulation method is carried out using the end plate assembly of the fuel cell stack in Embodiment 1:

[0032] First, the front end plate 6 of the stack (fixed to the housing 4 and serving as the wall surface of the housing 4), the stack core 5, the floating end plate 7, etc. are sequentially placed into the housing 4 in order;

[0033] Then, the rear end plate 1 (fixed to the housing 4 and serving as the wall surface of the housing 4) is installed, and pressure is applied to the rear end plate 1 so that the rear end plate 1 can be fitted to other wall surfaces of the housing 4 and assembled by means of threading, welding, riveting, tight fitting, or gluing, etc.;

[0034] Then, the flat surface on the core side of the bolt top plate 2 is pressed against the core 5, and the floating end plate 7 at the core end is limited by the bolt top plate 2, thereby providing the pressing force required for the normal operation of multiple single cells in the stack;

[0035] Finally, the adjusting nut 3 is rotated backward toward the rear end plate side until it is in close contact with the bottom of the counterbore 12 of the rear end plate 1, and then the pressure is removed;

[0036] A fuel cell module with an encapsulation housing is jointly composed of relevant structures and functional components such as a rear end plate 1, a floating end plate 7, a fuel cell stack core 5, a housing 4, and a front end plate 6.

[0037] The above description of the embodiments is for the convenience of those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative efforts. Therefore, the present invention is not limited to the above embodiments, and the improvements and modifications made by those skilled in the art without departing from the scope of the present invention according to the disclosure of the present invention should be within the protection scope of the present invention.

Claims

1. An end plate assembly of a fuel cell stack, characterized in that, It includes a rear end plate (1), a bolt top plate (2) and an adjusting nut (3); the rear end plate (1) is connected to a housing (4), and a coaxial through hole (11) and a counterbore (12) are provided on the rear end plate (1). The adjusting nut (3) is assembled in the through hole (11) and the counterbore (12). One end of the bolt top plate (2) is threadedly connected to the adjusting nut (3), and the other end is used to apply a pressing force to the core (5) inside the housing (4). The rear end plate (1) is one side for encapsulating the housing (4), and is connected to the housing (4) in a fixed or detachable manner. One end of the housing (4) is encapsulated by the rear end plate (1), and the other end is encapsulated by a front end plate (6). The bolt top plate (2) includes a top plate stud (21) and a top plate (22). The top plate stud (21) is threadedly connected to the adjusting nut (3), and the top plate (22) is used to apply a pressing force to the core (5). A floating end plate (7) is provided between the bolt top plate (2) and the core (5). A rapid encapsulation method using the end plate assembly of the fuel cell stack includes the following steps: S1: Sequentially place the front end plate (6), the core (5), and the floating end plate (7) into the housing (4). S2: Install the rear end plate (1), and then apply pressure to the rear end plate (1) so that the rear end plate (1) can be attached to and connected to the housing (4). S3: Press-fit between the top plate (22) on the core side of the bolt top plate (2) and the core (5), and limit the floating end plate (7) at the core end through the bolt top plate (2), so as to provide the pressing force required for the normal operation of multiple single cells in the stack. S4: Rotate the adjusting nut (3) backward until it is in close contact with the bottom of the counterbore (12) of the rear end plate (1), and then remove the pressure.

2. The end plate assembly of the fuel cell stack according to claim 1, wherein A threaded through hole (31) is provided in the adjusting nut (3).

3. The end plate assembly of the fuel cell stack according to claim 1, wherein The adjusting nut (3) includes a main body portion (32) and a flange plane (33). The main body portion (32) corresponds to the through hole (11), and the flange plane (33) corresponds to the counterbore (12).

4. The end plate assembly of the fuel cell stack according to claim 1, characterized in that, The diameter of the counterbore (12) is larger than that of the through hole (11).

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