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CN-122000405-A - Fuel cell for an aircraft

CN122000405ACN 122000405 ACN122000405 ACN 122000405ACN-122000405-A

Abstract

A fuel cell for an aircraft comprises a cell stack (2) comprising an anode (27), a cathode (29) and a proton exchange membrane (28), a front end plate (1) placed at one end of the cell stack (2), a rear end plate (3) placed at the other end of the cell stack (2), and an insulating panel (5, 8, 9) made of a polymer material placed between the cell stack (2) and one or both of the front end plate (1) and the rear end plate (3). The present invention allows to provide a fuel cell which solves the problem of electrical insulation of aviation fuel cells and allows to connect floating bond networks in an aircraft.

Inventors

  • Alfonso Delgado Orero
  • Monica Pardo Herrero
  • Inigo Uvernavidovro
  • Manuel sylvestre Salas

Assignees

  • 空中客车西班牙有限责任公司

Dates

Publication Date
20260508
Application Date
20251107
Priority Date
20241107

Claims (13)

  1. 1. A fuel cell for an aircraft, comprising: -a cell stack (2), the cell stack (2) comprising an anode (27), a cathode (29) and a proton exchange membrane (28); A front end plate (1), the front end plate (1) being placed at one end of the cell stack (2), and A rear end plate (3), the rear end plate (3) being placed at the other end of the cell stack (2), Characterized in that the fuel cell further comprises an insulating panel (5, 8, 9), the insulating panel (5, 8, 9) being made of a polymeric material, placed between the cell stack (2) and one or both of the front end plate (1) and the rear end plate (3).
  2. 2. The fuel cell for an aircraft of claim 1, wherein the insulating panel comprises: A first insulating sheet (5); A second insulating sheet (8), and -An insulating layer (9), the insulating layer (9) being placed between the first insulating sheet (5) and the second insulating sheet (8).
  3. 3. Fuel cell for an aircraft according to claim 1 or 2, wherein the insulating panel further comprises an additional insulating sheet (10), the additional insulating sheet (10) being placed between the first insulating sheet (5) and the front end plate (1) in contact with the first insulating sheet (5).
  4. 4. Fuel cell for an aircraft according to any of the preceding claims, wherein the insulating panel further comprises a seal (19, 21) placed in contact with the first insulating sheet (5).
  5. 5. The fuel cell for an aircraft according to claim 2, wherein the first insulating sheet (5) and the second insulating sheet (8) are made of 4,4' -oxydiphenylene-pyromellitic imide.
  6. 6. Fuel cell for an aircraft according to claim 2, wherein the first insulating sheet (5) and the second insulating sheet (8) are attached to the insulating layer (9).
  7. 7. Fuel cell for an aircraft according to claim 2, wherein the insulating layer (9) is made of polyetheretherketone or polyphenylene sulfide.
  8. 8. Fuel cell for an aircraft according to any of the preceding claims, wherein the front end plate (1) comprises an interface (4) for the ingress and egress of fluid, and an insulating reinforcement (11) is placed between the end interface (4) and the front end plate (1).
  9. 9. Fuel cell for an aircraft according to claim 8, wherein each insulating reinforcement (11) comprises a groove in which an O-ring (18) is housed.
  10. 10. Fuel cell for an aircraft according to claim 8, wherein the front end plate (1) comprises an insulating gasket (6) corresponding to the interface (4).
  11. 11. Fuel cell for an aircraft according to claim 2 or 5, wherein the first insulating sheet (5) and the second insulating sheet (8) have a thickness of less than 0.5 mm, preferably 20 to 80 μm.
  12. 12. The fuel cell for an aircraft of claim 1 wherein the proton exchange membrane (28) comprises a catalyst.
  13. 13. Fuel cell for an aircraft according to claim 1, wherein seals (32) are placed on both sides of the proton exchange membrane (28).

Description

Fuel cell for an aircraft Technical Field The present invention relates to a fuel cell for an aircraft, which solves the problem of electrical insulation of aviation fuel cells and allows to connect floating bond networks in the aircraft. Background A fuel cell is an electrochemical device that generates heat and electricity by electrochemically reacting fuel (hydrogen, methanol, natural gas, etc.) and oxygen at an anode, which can be used to power a vehicle or in stationary applications. Fuel cells have many advantages over conventional heat engines, such as fuel cell performance, fuel cell size, or dynamic response capability of the fuel cell in response to transients or demands, which are highly appreciated in the aerospace industry. However, there is still a long way to walk when talking about specific power, as weight is critical for aircraft to be onboard. Fuel cells can be manufactured in different forms and types according to their technology. There are low temperature Alkaline Fuel Cells (AFCs), polymer fuel cells (PEMFCs), direct Methanol Fuel Cells (DMFCs) and high temperature Solid Oxide Fuel Cells (SOFCs), molten Carbonate Fuel Cells (MCFCs) and high temperature polymer (HT-PEM) fuel cells. The fuel cell includes one or more cells mounted in series to form a stack. These cells include an anode where oxidation of fuel occurs and a cathode where oxygen is reduced to produce water. The anode and cathode are separated by a generally conductive membrane or ceramic, allowing free diffusion of ions from the anode to the cathode. On the membrane, catalyst particles are deposited on both sides. To improve gas diffusion on both sides of the membrane, carbon cloth or mesh is added to make the membrane conductive, thereby improving contact between the phases and providing a larger possible diffusion area. This portion is referred to as a gas diffusion layer or GDL. A number of polymer gaskets are placed between the two sides of the assembled membrane, catalyst membrane and GDL to seal the membrane on both sides with bipolar or monopolar plates placed at the ends of the stack. A bipolar plate is a plate made of any electrically conductive material with a morphology of channels through which hydrogen or fuel passes to the anode or through which oxygen or air passes to the cathode, thereby uniformly distributing the reagents on both sides of the membrane and effectively draining the reaction products, such as the water formed, avoiding the formation of hot spots on the membrane. The bipolar plate is called a bipolar plate because it serves as both a cathode and an anode, i.e., one side is the cathode of one cell and the other side is the anode of an adjacent cell. Inside the bipolar plate, which typically comprises two parts separated by a seal, a coolant is circulated which cools the fuel cell, if necessary and depending on the type of fuel cell, the coolant being like a housing. The unipolar plates are located at the ends of the stack, i.e. the unipolar plates are simple in that the unipolar plates have only one side through which air or fuel circulates, and the unipolar plates are the cathode or final anode depending on the cell arrangement of the stack. Adjacent to the unipolar plates are current collector plates made of copper or other conductive material, which are the fuel cell terminals for external electrical connection. To close the stack, end plates or closing plates are placed with the external interface. The plates are external to the stack and function to provide sufficient mechanical integrity to prevent "sandwich" disassembly. The plates may be made of different insulating materials such as thermoplastics (e.g., polyphenylene sulfide) or metals (e.g., anodized aluminum, stainless steel, etc.). On these plates there is a nominal current leakage, which may be higher or lower depending on the mass of the inner stacked insulation. On these plates there are placed mechanical interfaces, which can also be made of the same material as the end plates. These interfaces are responsible for interconnecting the different ports of the stack, i.e. oxygen or air, hydrogen or fuel and coolant, to auxiliary equipment, which allows the stack to operate. These interfaces communicate with all of the cells within them and the insulation of the interfaces is very important, since depending on the insulation there will be more or less current leakage towards the air and fuel supply and exhaust pipes, which should also be insulated and grounded. On these collector plates, an insulating layer or piece composed of a polymer or oxide is introduced in the form of a piece or coating, as mentioned for example in patent US6773841B2, which proposes the use of an electrowinning coating by PVD or CVD techniques, which include physical deposition (PVD) or chemical deposition (CVD) of the insulating material by means of plasma of its ions. This electrical insulation layer allows the stack to be electrically connected as a floati