Fuel cell pack structure integrated with dc / dc

Abstract

This invention relates to a fuel cell structure, specifically an integrated DC / DC fuel cell PACK structure, comprising a battery PACK system, a liquid cooling system, and a DC / DC converter. The liquid cooling system is fixed to the bottom of the DC / DC housing. The DC / DC converter, serving as the top cover of the battery PACK system, is fixed to the top of the battery PACK system. The DC / DC converter includes a DC / DC housing and electrical functional components fixed within the housing, with a high-voltage interface located at the bottom of the housing. The battery PACK system includes a PACK housing and a core module fixed within the housing. The core module includes at least a copper busbar and a fuel cell core. The copper busbar passes through and is fixed to the high-voltage interface, allowing direct connection between the battery PACK system and the DC / DC converter. Compared to existing technologies, this invention integrates multiple components, reducing the overall volume and weight of the fuel cell system while increasing power density.

Description

Technical Field

[0001] This invention relates to a fuel cell structure, and more specifically to a fuel cell PACK structure integrating DC / DC converters. Background Technology

[0002] With increasingly stringent environmental protection and emission reduction requirements, fuel cell electric vehicles have become a major direction for automotive development in the modern and future. The key power source of fuel cell electric vehicles is the fuel cell, and the fuel cell stack (encapsulated within the battery PACK system) is the system's power source and is naturally the most critical part of the system.

[0003] Furthermore, the DC / DC converter is one of the key components of this system, used to boost the low-voltage DC output from the fuel cell to a high-voltage DC output, providing power to the electric vehicle and charging the battery. Precise control of the fuel cell system's output power through the DC / DC converter enables power distribution and optimized control across the vehicle's powertrain.

[0004] In existing fuel cells, the battery pack system and DC / DC converter have long been used as two separate parts, typically stacked vertically or mounted side-by-side and secured with bolts. This assembly method results in numerous structural components, such as baffles and covers, occupying internal space and hindering the improvement of power density. Furthermore, sealing rings are required between the two mating structures; however, manufacturing and assembly processes significantly increase the likelihood of seal failure. In addition, current battery pack systems often rely on natural air cooling, which is inefficient and negatively impacts the fuel cell's power generation efficiency.

[0005] As can be seen from the above, the combination structure of the battery PACK system and the DC / DC converter still needs further improvement in order to reduce the size of the fuel cell, increase the power density, improve the sealing performance to ensure safe use, and improve the cooling efficiency of the fuel cell stack to increase the power generation efficiency. Summary of the Invention

[0006] The purpose of this invention is to solve at least one of the above problems by providing an integrated DC / DC fuel cell PACK structure that integrates the battery PACK system, water cooling system and DC / DC converter into one unit, thereby reducing the overall volume and weight of the fuel cell system and increasing the power density.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] A fuel cell PACK structure integrating DC / DC converter includes a battery PACK system, a liquid cooling system, and a DC / DC converter;

[0009] The liquid cooling system is integrated and fixed to the bottom of the DC / DC housing; the DC / DC converter is integrated and fixed to the top of the battery PACK system as the top cover.

[0010] The DC / DC converter includes a DC / DC housing and electrical functional components fixed inside the DC / DC housing. A high-voltage interface is provided at the bottom of the DC / DC housing.

[0011] The battery PACK system includes a PACK housing and a core module fixed inside the PACK housing; the core module includes at least a copper busbar and a fuel cell core; the copper busbar passes through the high-voltage interface and is fixedly installed with the high-voltage interface, so that the battery PACK system is directly connected to the DC / DC converter through the copper busbar.

[0012] Preferably, the liquid cooling system includes a liquid cooling plate and heat-conducting fins fixed to the back of the liquid cooling plate; the front of the liquid cooling system exchanges heat with electrical functional components through the liquid cooling plate, and the back of the liquid cooling system exchanges heat with the core module through the heat-conducting fins.

[0013] Preferably, the liquid cooling system uses water as the cooling fluid.

[0014] Preferably, the copper busbar includes a copper busbar and an injection-molded mounting structure, wherein the copper busbar and the injection-molded mounting structure are integrally injection molded; the injection-molded mounting structure includes an injection-molded body for fixing the copper busbar and a sealing surface that abuts against the high-voltage interface; after the copper busbar is fixed to the high-voltage interface, the sealing surface seals the high-voltage interface.

[0015] Preferably, the sealing surface is made of silicone.

[0016] Preferably, the sealing surface is made of foamed silicone.

[0017] Preferably, the sealing surface is made of EPDM material.

[0018] Preferably, the liquid cooling system is fixedly installed at the bottom of the DC / DC housing by welding.

[0019] Preferably, the electrical functional components include, but are not limited to, relays, resistors, and control boxes.

[0020] Preferably, the core module further includes, but is not limited to, an electrical system and a battery management system.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. This invention integrates a DC / DC converter, a liquid cooling system, and a battery pack system into a single unit, using the DC / DC converter's housing as the top cover of the battery pack system. Compared to existing split structures, this structure reduces system weight, manufacturing costs, and system size while increasing power density by eliminating one structural panel.

[0023] 2. The DC / DC converter and the battery PACK system of the present invention are directly connected by copper busbars, and with the sealing surface in the injection-molded mounting structure, the structural tolerances are effectively avoided from affecting the sealing effect, thus achieving isolation between the DC / DC converter and the battery PACK system and preventing gas escaping from the battery PACK system from entering the DC / DC converter and affecting the stability of the electrical components.

[0024] 3. The liquid cooling system is integrated and fixed at the bottom inside the DC / DC converter, sandwiched between the DC / DC converter and the battery PACK system. Therefore, this liquid cooling system is a shared cooling system for both the DC / DC converter and the battery PACK system. Its front side directly contacts the electrical components within the DC / DC converter for heat exchange via a water-cooled plate, while its back side exchanges heat with the fuel cell stack core within the battery PACK system via heat-conducting fins. During fuel cell operation, the cold fluid circulation of the liquid cooling system removes the heat generated by the electrical components and maintains the reaction thermal balance of the fuel cell stack core.

[0025] 4. The assembly process of this structure is simpler and more convenient. The DC / DC converter and battery PACK system can be pre-assembled outside the production line, reducing the assembly process on the final assembly line and thus accelerating the overall production cycle of the fuel cell. Attached Figure Description

[0026] Figure 1 A schematic diagram of a fuel cell PACK structure integrating DC / DC converters;

[0027] Figure 2 A top-view perspective view of the integrated DC / DC fuel cell PACK structure;

[0028] Figure 3 This is a schematic diagram of the DC / DC housing.

[0029] Figure 4 A schematic diagram of the structure of a fuel cell PACK integrating DC / DC converters;

[0030] Figure 5 A side perspective view of the fuel cell PACK structure integrating DC / DC converters;

[0031] Figure 6This is a schematic diagram of the copper busbar structure;

[0032] Figure 7 An exploded view of the structure of a fuel cell PACK integrating DC / DC converters;

[0033] Figure 8 A schematic diagram of the structural assembly of an existing DC / DC converter and battery pack system;

[0034] In the diagram: 1-Battery PACK system; 11-PACK housing; 12-Core module; 13-Copper busbar; 14-Injection molding mounting structure; 141-Injection molding body; 142-Sealing surface; 2-Liquid cooling system; 3-DC / DC converter; 31-DC / DC housing; 32-Electrical functional components; 33-High voltage interface; 4-Sealing ring. Detailed Implementation

[0035] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0036] like Figure 8 The diagram shows the structural assembly of the DC / DC converter 3 and the battery PACK system 1 in the prior art. It can be seen that the two mating structures are sealed with a sealing ring 4. The sealing performance of this sealing method is related to the assembly tolerance and the manufacturing tolerance of the sealing side, which may lead to a greater possibility of sealing failure.

[0037] Example 1

[0038] An integrated DC / DC fuel cell PACK structure, such as Figure 1-7 As shown, it includes a battery pack system 1, a liquid cooling system 2, and a DC / DC converter 3;

[0039] The liquid cooling system 2 is integrated and fixed to the bottom of the DC / DC housing 31; the DC / DC converter 3 is integrated and fixed to the top of the battery PACK system 1 as the top cover of the battery PACK system 1.

[0040] The DC / DC converter 3 includes a DC / DC housing 31 and electrical functional components 32 fixed inside the DC / DC housing 31. A high-voltage interface 33 is provided at the bottom of the DC / DC housing 31.

[0041] The battery PACK system 1 includes a PACK housing 11 and a core module 12 fixed inside the PACK housing 11; the core module 12 includes at least a copper busbar 13 and a fuel cell core; the copper busbar 13 passes through the high-voltage interface 33 and is fixedly installed with the high-voltage interface 33, so that the battery PACK system 1 is directly connected to the DC / DC converter 3 through the copper busbar 13.

[0042] More specifically, in this embodiment:

[0043] The structure consists of a battery pack system 1, a liquid cooling system 2, and a DC / DC converter 3. The liquid cooling system 2 is fixed to the bottom of the DC / DC converter 3 by welding. The DC / DC converter 3 serves as the top cover of the battery pack system 1 and is integrated with the battery pack system 1 by bolts, making the entire structure a single unit.

[0044] Liquid cooling system 2 adopts the form of a liquid cooling plate, which is connected to coolant pipes for coolant flow; heat exchange is performed on the back of the liquid cooling plate using heat-conducting fins, such as... Figure 4 In this embodiment, water can be used as the coolant. In other embodiments, conventional coolants can be selected according to actual heat exchange requirements.

[0045] The DC / DC converter 3 includes a DC / DC housing 31 and electrical functional components 32 fixed inside the DC / DC housing 31, such as relays, resistors, control boxes, etc. Figure 2 As shown. Several threaded blind holes are pre-drilled inside the DC / DC housing 31 for threaded mounting of these electrical functional components 32. For example... Figure 3 As shown, the bottom of the DC / DC housing 31 has two large openings, which are suitable for welding and fixing the liquid cooling plate of the liquid cooling system 2. The heat-conducting fins face downwards (towards the outside of the DC / DC housing 31). A high-voltage interface 33 is provided at one corner of the DC / DC housing 31.

[0046] The battery PACK system 1 consists of an outer PACK housing 11 and a core module 12 fixed inside the PACK housing 11. The core module 12 typically includes conventional components such as a fuel cell core and mounting structures. Furthermore, the core module 12 also includes a copper busbar 13 connecting the DC / DC converter 3 to the battery PACK system 1. This copper busbar 13 passes through a high-voltage interface 33 and is fixed to the high-voltage interface 33 by bolts. Figure 3 and Figure 6As can be seen, the copper busbar 13 consists of a pair of parallel, vertically arranged copper busbars and an injection-molded mounting structure 14, in which the injection-molded mounting structure 14 encapsulates the copper busbars through injection molding. The injection-molded mounting structure 14 can be further divided into an injection-molded body 141 and a sealing surface 142, both integrally molded. The injection-molded body 141 is mainly used to fix the configuration of the copper busbars; the sealing surface 142 is a boss-shaped structure that mates with the high-voltage interface 33. After the copper busbar 13 is fixed to the high-voltage interface 33, the sealing surface 142 completely abuts against the high-voltage interface 33, and the lower sealing surface 142 further adheres to the bottom of the DC / DC housing 31, fully forming a seal. This sealing effect not only meets conventional sealing requirements but also prevents the escaped reaction gas from the fuel cell stack from entering the DC / DC converter 3, preventing interference with the normal operation of the electrical components 32. The sealing surface 142 is typically made of foamed silicone, but is not limited to silicone; materials such as EPDM can also be used. Using a direct connection effectively avoids the impact of structural tolerances on the sealing effect.

[0047] Combination Figure 1 , Figure 4 and Figure 5 After the DC / DC converter 3 is bolted to the battery PACK system 1, the copper busbar 13 passes through the high-voltage interface 33, and the electrical functional component 32 is directly attached to the surface of the liquid cooling plate. The heat-conducting fins on the lower side of the liquid cooling plate extend into the battery PACK system 1. Through the water circulation in the liquid cooling system 2, the heat generated by the electrical functional component 32 during operation is removed, and the reaction thermal balance inside the PACK housing 11 is maintained. By eliminating a panel structure (the original battery PACK system 1 cover is replaced by the DC / DC converter 3), the overall system size is reduced, the system weight is reduced, and the system power density is increased.

[0048] Figure 7 The diagram shows an exploded view of the structure, which consists of three parts: the battery PACK system 1, the liquid cooling system 2, and the DC / DC converter 3, forming an integrated structure.

[0049] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A fuel cell PACK structure integrating DC / DC converters, characterized in that, It includes a battery pack system (1), a liquid cooling system (2), and a DC / DC converter (3). The liquid cooling system (2) is integrated and fixed to the bottom of the DC / DC housing (31); the DC / DC converter (3) is integrated and fixed to the top of the battery PACK system (1) as the top cover of the battery PACK system (1); The DC / DC converter (3) includes a DC / DC housing (31) and electrical functional components (32) fixed inside the DC / DC housing (31). A high-voltage interface (33) is provided at the bottom of the DC / DC housing (31). The battery PACK system (1) includes a PACK housing (11) and a core module (12) fixed inside the PACK housing (11); the core module (12) includes at least a copper busbar (13) and a fuel cell core; the copper busbar (13) passes through the high-voltage interface (33) and is fixedly installed with the high-voltage interface (33), so that the battery PACK system (1) is directly connected to the DC / DC converter (3) through the copper busbar (13); The copper busbar (13) includes a copper busbar and an injection molding mounting structure (14). The copper busbar and the injection molding mounting structure (14) are integrally injection molded. The injection molding mounting structure (14) includes an injection molding body (141) for fixing the copper busbar and a sealing surface (142) that abuts against the high-voltage interface (33). The sealing surface (142) is a boss-shaped part that cooperates with the high-voltage interface (33). After the copper busbar (13) is fixed to the high-voltage interface (33), the sealing surface (142) abuts against the high-voltage interface (33), and the lower part of the sealing surface (142) is also in contact with the bottom of the DC / DC housing (31) to fully form a seal, which is used to prevent the reaction gas escaping from the fuel cell stack from entering the DC / DC converter (3).

2. The fuel cell PACK structure with integrated DC / DC according to claim 1, characterized in that, The liquid cooling system (2) includes a liquid cooling plate and heat-conducting fins fixed to the back of the liquid cooling plate; the front of the liquid cooling system (2) exchanges heat with the electrical functional components (32) through the liquid cooling plate, and the back of the liquid cooling system (2) exchanges heat with the core module (12) through the heat-conducting fins.

3. The fuel cell PACK structure with integrated DC / DC according to claim 2, characterized in that, The liquid cooling system (2) uses water as the cooling fluid.

4. The integrated DC / DC fuel cell PACK structure according to claim 1, characterized in that, The sealing surface (142) is made of silicone.

5. The fuel cell PACK structure with integrated DC / DC according to claim 4, characterized in that, The sealing surface (142) is made of foamed silicone.

6. The fuel cell PACK structure with integrated DC / DC according to claim 1, characterized in that, The sealing surface (142) is made of EPDM material.

7. The fuel cell PACK structure with integrated DC / DC according to claim 1, characterized in that, The liquid cooling system (2) is fixedly installed at the bottom of the DC / DC housing (31) by welding.

8. The integrated DC / DC fuel cell PACK structure according to claim 1, characterized in that, The electrical functional components (32) include relays, resistors, and control boxes.

9. The fuel cell PACK structure with integrated DC / DC according to claim 1, characterized in that, The core module (12) also includes an electrical system and a battery management system.

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