A novel structure for air-cooled fuel cell stacks

Abstract

This invention relates to the field of fuel cell technology and discloses a novel air-cooled fuel cell stack design. The stack employs a modular design, distributed heat dissipation, and a highly symmetrical annular star-shaped layout to optimize the gas supply path and improve thermal management efficiency. Its core structure includes a cylindrical gas supply chamber located at the center of the stack, uniformly supplying hydrogen and air. Modular cells are arranged in an annular star-shaped pattern around the gas supply chamber, with heat sinks on both sides, forming wedge-shaped heat dissipation channels between adjacent modules. The modular design reduces the impact of individual cell module failures on the overall system, avoids the bottleneck effect, and improves reliability. The symmetrical and distributed heat sink layout prevents core overheating while ensuring uniform heat dissipation and reducing airflow dead zones. The compact and symmetrical arrangement of cell modules around the gas supply chamber shortens the gas supply path, achieving efficient and uniform gas supply and improving the overall performance of the stack. This invention improves gas supply uniformity and heat dissipation efficiency, reduces the bottleneck effect, enhances system stability, and facilitates the development of more stable, higher-power, and lightweight fuel cell stacks, enhancing the applicability of fuel cell stacks in scenarios such as drones and aerospace.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and in particular to a novel proton exchange membrane fuel cell (PEMFC) stack design, which aims to significantly improve its heat dissipation efficiency, gas supply uniformity, and overall operational stability to meet the needs of high-power applications. Background Technology

[0002] A fuel cell is a device that efficiently converts the chemical energy of fuel (such as hydrogen) into electrical energy. Its working principle is based on electrochemical reactions and is not limited by the Carnot cycle, thus exhibiting high energy conversion efficiency. Furthermore, fuel cells have no moving mechanical parts during operation, resulting in extremely low noise, making them suitable for applications requiring both quiet operation and high efficiency. Air-cooled fuel cell stacks, due to their lighter weight, hold significant application potential in fields such as aviation and drones. However, current air-cooled fuel cells still face the following key challenges in practical applications:

[0003] 1. Thermal Management Issues: Fuel cells continuously generate a large amount of heat during operation. If the cooling system fails to function effectively or uneven heat dissipation occurs, it will directly affect the battery's performance stability and lifespan, and may even lead to safety hazards. Currently, air-cooled fuel cell stacks have relatively limited heat dissipation capacity due to the lack of a liquid cooling circulation system, and are mainly used in low-power applications. To overcome this limitation and improve the power output of air-cooled fuel cells, their thermal management structure must be optimized to enhance heat dissipation capacity.

[0004] 2. Uniformity of Gas Supply and Cooling: Existing air-cooled fuel cell stacks mainly employ two gas supply methods: open-loop and closed-loop. In the open-loop method, the airflow for cooling and the cathode airflow merge, making it difficult to achieve high-pressure gas supply and limiting fuel cell performance. Furthermore, the common cubic stack structure easily creates airflow dead zones at the corners, leading to localized gas shortages and affecting the overall stack efficiency. The closed-loop method, on the other hand, separates the reaction gas supply path and the cooling airflow path, isolating the air required for the reaction and the air needed for cooling. However, the problem of gas shortages at the corners, present in the first method, persists in the cooling channel. For the reaction gas supply path, common designs require the gas path to traverse all cell units, resulting in a long flow path, significant pressure loss, and even preventing the airflow from reaching the end cell. Therefore, for air-cooled fuel cells, the uniformity of gas supply and cooling needs further optimization.

[0005] 3. Bottleneck Effect: Fuel cell stacks typically consist of multiple cells connected in series. If the performance of any one cell deteriorates, it will negatively impact the output power of the entire stack, creating a bottleneck effect. This not only reduces system reliability but also increases the risk of failure, making battery life and maintenance costs significant challenges.

[0006] In view of the above-mentioned technical difficulties, this invention proposes a novel air-cooled fuel cell stack design, which aims to optimize the gas supply path, improve heat dissipation efficiency, and reduce the impact of the bottleneck effect, thereby making it suitable for higher power air-cooled fuel cell application scenarios. Summary of the Invention

[0007] This invention provides an innovative air-cooled fuel cell stack, employing a modular design, distributed heat dissipation, and a highly symmetrical annular star-shaped structure. By optimizing airflow distribution, it improves heat dissipation capacity and significantly reduces the impact of the bottleneck effect on system stability. The air-cooled fuel cell stack includes: a gas supply chamber, a battery module, wedge-shaped heat dissipation ducts, and heat sinks.

[0008] The gas supply chamber is located at the center of the fuel cell stack and adopts a cylindrical structure. One end of the battery module is nested in its wall, and it has independent hydrogen supply chambers and air supply chambers, which are isolated from each other and each has an air inlet. The gas supply chamber has a certain degree of airtightness and can maintain a gas supply pressure higher than atmospheric pressure, thereby improving the power output of the fuel cell stack. At the same time, a heat exchanger or heating device, as well as a humidifier or dehumidifier, can be installed inside the gas supply chamber to regulate the inlet air temperature and humidity to adapt to liquid hydrogen supply or special environmental conditions.

[0009] The battery module is rectangular in shape, with one end embedded in the gas supply chamber wall, and arranged in a circular, star-shaped pattern around the gas supply chamber. Each battery module consists of multiple fuel cell cells stacked in series, and each cell includes a membrane electrode assembly, bipolar plates, and end plates (anode and cathode plates). This design ensures uniform gas supply to all battery modules and shortens the gas supply path, avoiding impacts on stack performance due to insufficient gas supply. Furthermore, the modular design reduces the impact of the weakest link effect, ensuring that a failure in a single module will not affect the entire stack, thus improving system reliability.

[0010] The heat sinks are evenly distributed on both sides of each battery module, arranged around the air supply chamber to form a distributed heat dissipation structure. This design effectively removes heat generated by each battery module, avoiding the overheating problem of the traditional cubic structure battery stack core, thereby improving overall heat dissipation performance. The shape and groove direction of the heat sinks can be optimized according to specific ventilation conditions to further enhance the heat dissipation effect.

[0011] The aforementioned heat dissipation duct is formed by the gaps between adjacent battery modules, and its shape is wedge-shaped along the arrangement direction of the battery modules. A fan is positioned on one side of the battery stack, allowing cooling air to flow along the duct and carry away heat from the heat sink. This structure, combined with the cylindrical battery stack design, ensures uniform heat dissipation for each battery module, avoids airflow dead zones that are prone to occur in square structures, and improves overall heat dissipation efficiency.

[0012] This invention achieves efficient heat dissipation and uniform gas supply in air-cooled fuel cell stacks through modular, distributed heat dissipation and a highly symmetrical annular star-shaped structure, reducing the bottleneck effect, improving system reliability, and making it suitable for higher-power air-cooled fuel cell applications. Attached Figure Description

[0013] Figure 1 : A schematic diagram of the overall structure of the present invention.

[0014] Figure 2 : Overall structural cross-sectional view of the present invention.

[0015] Figure 3 : A schematic diagram of the battery module structure of the present invention.

[0016] In the diagram: 1-Air supply chamber, 2-Battery module, 3-Heat dissipation duct, 4-Heat sink, 5-Air supply chamber inlet, 6-Separator, 7-Battery module inlet, 8-Membrane electrode, 9-Bipolar plate, 10-Cathode plate, 11-Anode plate. Detailed Implementation

[0017] Preferred embodiments of the present invention will be described in further detail with reference to the accompanying drawings. This description is only directed at specific typical embodiments and is used to explain the present invention only, and does not constitute a limitation on its scope of protection.

[0018] The air-cooled fuel cell stack of the present invention includes a gas supply chamber (1), several battery modules (2), a heat dissipation duct (3), and heat sinks (4). The gas supply chamber (1) has air inlets (5) at its upper and lower ends, and is internally divided into a hydrogen supply chamber and an air supply chamber by a partition (6). Battery module air inlets (7) are located on the side walls. Each battery module (2) consists of a membrane electrode (8), bipolar plates (9), and end plates (including a cathode plate (10) and an anode plate (11)). The specific workflow is as follows:

[0019] 1. Hydrogen and air enter the corresponding supply chambers through the air inlets (5) at the top and bottom of the supply chamber (1), and then enter each battery module (2) through the battery module air inlet (7).

[0020] 2. Inside the battery module, hydrogen flows along the anode side channel of the bipolar plate, and air flows along the cathode side channel. Hydrogen and oxygen in the air undergo an electrochemical reaction at the membrane electrode (8), resulting in charge transfer and the generation of current.

[0021] 3. Each battery module operates relatively independently. If a module fails, it will not affect the normal operation of the entire battery stack.

[0022] 4. The heat generated during the reaction is transferred to the heat sink (4) through thermal conduction and thermal convection of the internal airflow. The fan sends cool air into the wedge-shaped heat dissipation channel (3), which flows over the surface of the heat sink (4) and carries away the heat, achieving efficient heat dissipation.

[0023] Summarize

[0024] This invention employs an optimized gas supply method, modular design, and distributed heat dissipation technology, significantly improving heat dissipation uniformity and gas supply efficiency, effectively reducing the bottleneck effect, and enhancing the reliability of the fuel cell stack. Its compact overall structure makes it particularly suitable for lightweight, high-power applications such as aviation and drones.

Claims

1. A novel air-cooled fuel cell stack, characterized in that, It includes an air supply chamber, battery module, heat sink, and wedge-shaped heat dissipation air duct. The gas supply chamber (1) is located at the center of the fuel cell stack and has a cylindrical structure. It is divided into a hydrogen supply chamber and an air supply chamber, which are isolated from each other and are equipped with air inlets (5) to provide hydrogen and oxygen required for the reaction. The size of the hydrogen and air supply chambers can be adjusted according to the needs. Both chambers have airflow channels leading to the battery module. The battery module (2) is in the shape of a cuboid. Several battery modules are arranged in a circular star pattern around the gas supply chamber (1). Each battery module is composed of several fuel cell cells stacked in series. The heat sink (4) is disposed on both sides of each battery module (2) and distributed around the air supply chamber (1) to achieve distributed heat dissipation and improve thermal management efficiency; the shape and groove direction of the heat sink (4) can be optimized according to specific ventilation conditions to meet the needs of different application scenarios. The wedge-shaped heat dissipation air duct (3) is formed between adjacent battery modules (2) and has a wedge-shaped structure along the battery module arrangement direction. It allows cooling air to flow along the wedge-shaped air duct (3) and carry away the heat on the heat sink (4), thereby achieving efficient heat dissipation.

2. The novel air-cooled fuel cell stack according to claim 1, characterized in that, Each battery module is directly connected to the gas supply chamber. The airflow paths of each module are connected in parallel rather than in series, which shortens the supply paths for both air and hydrogen, reduces pressure loss during gas transport, improves gas supply efficiency, and ensures that all battery modules receive a uniform supply of reaction gas.

3. The novel air-cooled fuel cell stack according to claim 1, characterized in that, The modular stack structure is adopted, and the entire stack is composed of several independent battery modules. This ensures that if a single battery module fails, it will not affect the normal operation of other modules, thereby reducing the impact of the weakest link effect on the overall stack performance.

4. The novel air-cooled fuel cell stack according to claim 1, characterized in that, The gas supply chamber (1) may be equipped with a heat exchanger or heating device, as well as dehumidification and humidification devices, to adjust the gas supply temperature and humidity to adapt to liquid hydrogen supply or special air environment conditions.

5. The novel air-cooled fuel cell stack according to claim 1, characterized in that, The gas supply chamber (1) allows the gas to be supplied under certain pressure by means of a gas pump, thereby improving the efficiency of the fuel cell stack.

6. The novel air-cooled fuel cell stack according to claim 1, characterized in that, The wedge-shaped air duct (3) combined with the overall cylindrical structure of the fuel cell stack allows the heat dissipation air to flow evenly through all battery modules, avoiding the formation of airflow dead zones, improving heat dissipation uniformity, and thus enhancing the overall efficiency and stability of the fuel cell stack.

7. The novel air-cooled fuel cell stack according to claim 1, characterized in that, The connection between the gas supply chamber (1) and the battery module (2) adopts a high-efficiency sealing structure to reduce gas leakage, improve fuel utilization, and enhance system safety.

8. The novel air-cooled fuel cell stack according to claim 1, characterized in that, The battery module (2) adopts a detachable design, which facilitates maintenance, replacement or expansion, and enables the fuel cell stack to be flexibly configured according to different power requirements.

9. The novel air-cooled fuel cell stack according to claim 1, characterized in that, The fuel cell stack adopts a lightweight structural design to reduce system weight and improve its applicability in lightweight, high-power applications such as aviation and drones.

10. The novel air-cooled fuel cell stack according to claim 1, characterized in that, The fuel cell stack shell is made of corrosion-resistant material to improve environmental adaptability and ensure long-term stable operation of the system under extreme conditions such as high temperature, high humidity, and low temperature.

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