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JP-7855917-B2 - Power extraction structure of fuel cell stack

JP7855917B2JP 7855917 B2JP7855917 B2JP 7855917B2JP-7855917-B2

Inventors

  • 礒田 博之

Assignees

  • 日産自動車株式会社

Dates

Publication Date
20260511
Application Date
20220512

Claims (15)

  1. A power extraction structure for a solid oxide fuel cell stack mounted on a vehicle and connected to an electrical load, A first conductor that mediates the supply of power from the fuel cell stack to the electrical load, In the power supply path from the fuel cell stack to the electrical load, a second conductor is disposed between the first conductor and the electrical load, A relay electrode that relays power supply from the first conductor to the second conductor, The housing housing the fuel cell stack includes a fixing part for fixing the fuel cell stack, It has, The aforementioned fixing portion includes a housing fixing portion that is fixed to the housing and an insulating relay electrode fixing portion. The relay electrode fixing portion is supported by the housing fixing portion, The relay electrode is fixed on the relay electrode fixing portion so as to be insulated from the housing. A power extraction structure for a fuel cell stack, characterized by the following features.
  2. A power extraction structure for a fuel cell stack according to claim 1, The relay electrode fixing part is inserted from the outside to the inside of the housing, The housing fixing portion is fixed in close contact with the housing on the outside of the housing. A power extraction structure for a fuel cell stack, characterized by the following features.
  3. A power extraction structure for a fuel cell stack according to claim 2, The housing fixing portion is fixed to the housing via a gasket. A power extraction structure for a fuel cell stack, characterized by the following features.
  4. A power extraction structure for a fuel cell stack according to claim 3, The aforementioned gasket is a metal gasket. A power extraction structure for a fuel cell stack, characterized by the following features.
  5. A power extraction structure for a fuel cell stack according to claim 4, The aforementioned metal gasket is made of a material with high thermal conductivity and low hardness. A power extraction structure for a fuel cell stack, characterized by the following features.
  6. A power extraction structure for a fuel cell stack according to claim 1, The aforementioned relay electrode is a busbar, having a cross-sectional area corresponding to the current flowing in the direction of conduction, and having screw holes along the plate thickness direction. The thickness of the relay electrode plate is such that it is sufficient for the screw hole. A power extraction structure for a fuel cell stack, characterized by the following features.
  7. A power extraction structure for a fuel cell stack according to claim 6, The relay electrode has a heat sink portion on a surface other than the surface facing the fixed portion. A power extraction structure for a fuel cell stack, characterized by the following features.
  8. A power extraction structure for a fuel cell stack according to claim 7, The heat sink portion is composed of a plurality of fins extending along the conductive direction. A power extraction structure for a fuel cell stack, characterized by the following features.
  9. A power extraction structure for a fuel cell stack according to claim 1, The aforementioned relay electrode fixing portion is made of insulating ceramics. A power extraction structure for a fuel cell stack, characterized by the following features.
  10. A power extraction structure for a fuel cell stack according to claim 9, The insulating ceramic has high thermal conductivity. A power extraction structure for a fuel cell stack, characterized by the following features.
  11. A power extraction structure for a solid oxide fuel cell stack mounted on a vehicle and connected to an electrical load, A first conductor that mediates the supply of power from the fuel cell stack to the electrical load, In the power supply path from the fuel cell stack to the electrical load, a second conductor is disposed between the first conductor and the electrical load, A relay electrode that relays power supply from the first conductor to the second conductor, The housing housing the fuel cell stack includes a fixing part for fixing the fuel cell stack, It has, The fixing portion comprises a housing fixing portion fixed to the housing, a relay electrode fixing portion to which the relay electrode is fixed, and an insulating collar attached to the relay electrode fixing portion. The relay electrode fixing portion is supported by the housing fixing portion, The relay electrode is fixed to the relay electrode fixing portion via the insulating collar so as to be insulated from the housing. A power extraction structure for a fuel cell stack, characterized by the following features.
  12. A power extraction structure for a fuel cell stack according to claim 11, The insulating collar is made of insulating ceramics. A power extraction structure for a fuel cell stack, characterized by the following features.
  13. A power extraction structure for a fuel cell stack according to claim 11, The aforementioned relay electrode fixing portion is made of a heat-resistant metal. A power extraction structure for a fuel cell stack, characterized by the following features.
  14. A power extraction structure for a fuel cell stack according to claim 13, The heat-resistant metal has high thermal conductivity. A power extraction structure for a fuel cell stack, characterized by the following features.
  15. A power extraction structure for a fuel cell stack according to claim 1, The relay electrode is positioned on the fuel cell stack side relative to the relay electrode fixing portion. The fixing portions of the first conductor and the second conductor are each positioned on the electrical load side with respect to the relay electrode fixing portion. A power extraction structure for a fuel cell stack, characterized by the following features.

Description

This invention relates to a power extraction structure for a fuel cell stack. Patent Document 1 discloses a solid oxide fuel cell system comprising a fuel cell stack, a round bar-shaped current output member having one end connected to the fuel cell stack and the other end threaded, a terminal connected to the other end, and a current cable connected to the terminal. Japanese Patent Publication No. 2009-289435 Figure 1 is an exploded perspective view of an in-vehicle fuel cell system.Figure 2 shows the power extraction structure in an in-vehicle configuration.Figure 3 is a perspective view of the power extraction structure.Figure 4 is an exploded perspective view of the power extraction structure.Figure 5 shows the relay electrode as a standalone unit.Figure 6 is a first explanatory diagram of the installation structure of the first mount.Figure 7 is a second explanatory diagram of the installation structure of the first mount.Figure 8 shows an example of a material used for gaskets.Figure 9 shows an example of metal materials focusing on hardness and thermal conductivity.Figure 10 shows an example of a ceramic material that focuses on insulating properties.Figure 11 shows an example of ceramic material focusing on thermal conductivity.Figure 12 is the first diagram illustrating the heat dissipation mechanism in the power extraction structure.Figure 13 is the second diagram illustrating the heat dissipation mechanism in the power extraction structure.Figure 14 is an explanatory diagram of the heat dissipation mechanism from the mounting section.Figure 15 is the first diagram illustrating the heat dissipation methods according to the configuration.Figure 16 is the second diagram illustrating the heat dissipation methods according to the configuration.Figure 17 shows the power extraction structure as viewed from the rear of the vehicle.Figure 18 shows an example of a metal material whose toughness is a key feature.Figure 19 shows an example of a heat-resistant metal material, focusing on its thermal conductivity.Figure 20 is a partially exploded view of the power extraction structure according to the second modified example.Figure 21 is a perspective view of the power extraction structure according to the second modified example.Figure 22 is a perspective view of the power extraction structure according to the third modified example. The embodiments of the present invention will be described below with reference to the attached drawings. Figure 1 is an exploded perspective view of an on-board fuel cell system (hereinafter also referred to as the "fuel cell system") 100. In this embodiment, a fuel cell system 100 mounted on an electric vehicle powered by a drive motor will be used as an example. Furthermore, this embodiment assumes a solid oxide fuel cell. The fuel cell system 100 comprises a power generation structure A and a power generation structure case B that houses the power generation structure A. There are three main reasons for housing the power generation structure A in the power generation structure case B. Firstly, it is necessary to securely fix the power generation structure A to the vehicle body while preventing damage due to collisions or interference with other parts. Secondly, since the fuel used is mainly flammable and odorless, it is necessary to suppress leakage from fuel piping, etc., to a level below the flammability limit. Thirdly, solid oxide fuel cells have high power generation temperatures (over 500°C), and this temperature needs to be maintained during system operation. On the other hand, other auxiliary equipment and on-board components housed in the prime mover compartment do not have resistance to such high temperatures. Therefore, insulation is necessary to suppress temperature drops due to heat dissipation, and heat shielding is necessary to protect other auxiliary equipment, etc. The power generation structure A has an auxiliary equipment structure 103 positioned between the first fuel cell stack 101 and the second fuel cell stack 102, with the second fuel cell stack 102, auxiliary equipment structure 103, and first fuel cell stack 101 stacked in that order from bottom to top. The auxiliary equipment structure 103 is a housing that encloses auxiliary equipment (heat exchanger, combustor, etc.) that exchanges gas with the first fuel cell stack 101 and the second fuel cell stack 102. Both the first fuel cell stack 101 and the second fuel cell stack 102 consist of single cells stacked vertically within the vehicle body. The power generation structure case B has a split structure and includes a front member 104 positioned on the front side in the vehicle's longitudinal direction and a rear member 105 positioned on the rear side in the vehicle's longitudinal direction. The front member 104 has a box shape consisting of a front surface 104a, which is the leading edge in the vehicle's longitudinal direction when mounted, two side surfaces 104b extending to the rear of the vehicle f