US-20260128333-A1 - FUEL CELL

US20260128333A1US 20260128333 A1US20260128333 A1US 20260128333A1US-20260128333-A1

Abstract

A fuel cell is described that uses a movable overpressure prevention unit to automatically narrow the fluid flow path when internal pressure exceeds a safe limit. The system includes a cell stack for power generation, a fluid supply unit, and conduits directing air, hydrogen, or coolant to the stack. An overpressure prevention member is biased by an elastic element so it remains out of the flow under normal conditions. At higher pressure, it moves into the path, limiting the cross-sectional area and lowering pressure. A variant employs an extension bracket between separate conduits, replacing a standard hose bracket while integrating the same protective mechanism. Additionally, a method is disclosed in which an extension bracket with an overpressure prevention member helps prevent damage to components by automatically engaging when fluid pressure surpasses a set threshold.

Inventors

Jae Bum Lim

Assignees

HYUNDAI MOTOR COMPANY
KIA CORPORATION

Dates

Publication Date: 20260507
Application Date: 20250219
Priority Date: 20241104

Claims (20)

1 . A fuel cell comprising: a cell stack configured to generate electric power from electrochemical reactions; a fluid management unit configured to supply a fluid to the cell stack; a conduit defining a flow path for the fluid between the fluid management unit and the cell stack; and an overpressure prevention unit disposed in the pipe and configured to regulate a cross-sectional area of the flow path in response to a hydraulic pressure of the fluid.
2 . The fuel cell of claim 1 , wherein the overpressure prevention unit comprises: a protruding portion extending outward from the conduit and defining an accommodation space in fluid communication with the flow path, an overpressure prevention member movably disposed within the accommodation space, a support member configured to retain the overpressure prevention member in the accommodation space unless displaced by a predetermined fluid pressure, and an elastic member biased against the overpressure prevention member in a direction opposite the fluid flow, such that when the fluid pressure exceeds the biasing force of the elastic member, at least part of the overpressure prevention member moves into the flow path to reduce the cross-sectional area.
3 . The fuel cell according to claim 2 , wherein the overpressure prevention member includes: a first side surface being in contact with the support member, the first side surface receiving the hydraulic pressure; a second side surface formed opposite the first side surface, the second side surface formed to be in contact with the elastic member; and a third side surface formed between the first side surface and the second side surface, the third side surface having an inclined cross-section, and wherein, when the overpressure prevention member is pushed toward the elastic member by the fluid, a corner portion at which the second side surface and the third side surface meet each other enters the flow path, thereby reducing the cross-sectional area of the flow path.
4 . The fuel cell according to claim 1 , wherein the fluid management unit includes: an air processing system configured to manage inflow and outflow of air into and from the cell stack; a fuel processing system configured to manage inflow and outflow of hydrogen into and from the cell stack; and a thermal management system configured to manage inflow and outflow of a cooling medium into and from the cell stack, and wherein the conduit includes: an air conduit disposed between the air processing system and the cell stack; a hydrogen conduit disposed between the fuel processing system and the cell stack; and a cooling conduit disposed between the thermal management system and the cell stack.
5 . The fuel cell according to claim 4 , wherein the overpressure prevention unit is disposed in at least one of the air conduit, the hydrogen conduit, or the cooling conduit.
6 . The fuel cell according to claim 1 , wherein the conduit includes a plurality of separate conduits, and wherein the overpressure prevention unit is disposed between the plurality of separate conduits to interconnect the plurality of separate conduits.
7 . The fuel cell according to claim 1 , wherein the overpressure prevention unit includes first and second overpressure prevention units disposed opposite each other with the flow path interposed therebetween in a direction intersecting a flow direction of the fluid.
8 . The fuel cell according to claim 7 , wherein the first and second overpressure prevention units have cross-sectional shapes symmetrical to each other with respect to the flow path.
9 . The fuel cell according to claim 2 , wherein the elastic member has an elasticity allowing the elastic member to be compressed by the overpressure prevention member when the hydraulic pressure is higher than a first predetermined pressure.
10 . The fuel cell according to claim 2 , wherein the overpressure prevention member linearly reduces the cross-sectional area of the flow path in proportion to the hydraulic pressure received thereby.
11 . The fuel cell according to claim 2 , wherein the overpressure prevention member nonlinearly reduces the cross-sectional area of the flow path in proportion to the hydraulic pressure received thereby.
12 . The fuel cell according to claim 2 , wherein the accommodation space includes: a first accommodation space communicating with the flow path and accommodating the overpressure prevention member; and a second accommodation space neighboring the first accommodation space and accommodating the elastic member.
13 . The fuel cell according to claim 12 , further comprising a blocking portion disposed between the flow path and the second accommodation space to block the fluid from flowing into the second accommodation space.
14 . A fuel cell system comprising: a cell stack configured to generate electric power from electrochemical reactions, a fluid management unit configured to supply at least one fluid to the cell stack, a first fluid conduit and a second fluid conduit arranged to direct the at least one fluid, and an extension bracket fluidly coupling the first fluid conduit to the second fluid conduit, wherein the extension bracket integrates an overpressure prevention structure including: an overpressure prevention member configured to protrude into a flow path through the bracket in response to fluid pressure exceeding a predetermined threshold, and an elastic member applying a biasing force that retains the overpressure prevention member outside the flow path during normal operating pressure.
15 . The fuel cell system of claim 14 , wherein the extension bracket replaces a hose bracket, thereby reducing the need for a separate bracket to connect the first fluid conduit and the second fluid conduit.
16 . The fuel cell system of claim 14 , wherein the overpressure prevention structure further comprises a guide portion configured to restrain the overpressure prevention member from inadvertently shifting into the flow path when fluid pressure is below the predetermined threshold.
17 . The fuel cell system of claim 14 , wherein the overpressure prevention structure is configured to be applicable to any one or more of hydrogen flow, air flow, or coolant flow within the fuel cell system.
18 . The fuel cell system of claim 14 , further comprising a vehicle body, wherein the cell stack is mounted on the vehicle body and the extension bracket is disposed along at least one fluid line supplying the cell stack within the vehicle.
19 . A method of preventing overpressure in a fuel cell system, comprising: disposing, between a fluid management unit and a cell stack, an overpressure prevention unit having an overpressure prevention member and an elastic member arranged in an extension bracket that interconnects two fluid conduits; maintaining the overpressure prevention member out of a fluid flow path when fluid pressure is below a predetermined threshold; and automatically reducing a cross-sectional area of the fluid flow path by allowing the overpressure prevention member to protrude into the flow path when the fluid pressure exceeds the predetermined threshold.
20 . The method of claim 19 , further comprising selecting a spring constant for the elastic member based on the predetermined threshold, wherein the overpressure prevention member remains fully retracted during normal operating conditions and only protrudes into the flow path upon detecting the predetermined overpressure condition.

Description

This application claims under 35 U.S.C. § 119(a) the benefit of Korean Patent Application No. 10-2024-0154397, filed on Nov. 4, 2024, which is hereby incorporated by reference as if fully set forth herein. BACKGROUND Technical Field Embodiments relate to a fuel cell. Background A fuel cell receives hydrogen and air to generate power, and maintains an appropriate temperature for power generation using coolant. In order to deliver fluids such as hydrogen, air, and coolant to an outlet of the fuel cell, high fluid pressure is required. Hydrogen stored in a hydrogen tank is supplied with the pressure thereof lowered, air is supplied with the pressure thereof increased by an air compressor, and coolant is supplied with the pressure thereof increased by a compressor. If components of a fuel cell are exposed to high-pressure fluid, the components may be degraded, and the performance of the fuel cell may deteriorate. In order to prevent this, a pressure sensor is disposed in a flow path, and a compressor is controlled based on the pressure detected by the pressure sensor. However, this configuration is not sufficient to protect components of a fuel cell from high-pressure fluid. Therefore, research with the goal of solving the above problem is underway. SUMMARY Accordingly, embodiments are directed to a fuel cell that substantially obviates one or more problems due to limitations and disadvantages of the related art. Embodiments provide a fuel cell capable of protecting components thereof from high pressure of fluid. However, the objects to be accomplished by the embodiments are not limited to the above-mentioned objects, and other objects not mentioned herein will be clearly understood by those skilled in the art from the following description. Additional advantages, objects, and features of the disclosure will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the disclosure. The objectives and other advantages of the disclosure may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. A fuel cell according to some embodiments may include a cell stack including a plurality of unit cells stacked one above another, a fluid management unit configured to supply a fluid required for generation of power by the cell stack, a pipe disposed between the fluid management unit and the cell stack to form a flow path through which the fluid flows, and an overpressure prevention unit disposed in the pipe to regulate the area of the flow path in accordance with the hydraulic pressure of the fluid. In an aspect, a fuel cell is provided that comprises: 1) a cell stack configured to generate electric power from electrochemical reactions; 2) a fluid management unit configured to supply a fluid to the cell stack; 3) a conduit defining a flow path for the fluid between the fluid management unit and the cell stack; and 4) an overpressure prevention unit disposed in the pipe and configured to regulate a cross-sectional area of the flow path in response to a hydraulic pressure of the fluid. In an example, the overpressure prevention unit may include a protruding portion protruding outward from the pipe to define an accommodation space at least partially communicating with the flow path, an overpressure prevention member disposed in the accommodation space so as to receive the hydraulic pressure of the fluid flowing through the pipe, an elastic member disposed in the accommodation space to apply spring force to the overpressure prevention member in a direction opposite the flow direction of the fluid, and a support member configured to support the overpressure prevention member. The overpressure prevention member may be shaped to at least partially move to the flow path from the accommodation space in order to reduce the area of the flow path when the hydraulic pressure received by the overpressure prevention member is greater than the spring force. In an example, the overpressure prevention member may include a first side surface formed to be in contact with the elastic member, a second side surface formed to be opposite the first side surface, to be in contact with the support member, and to receive the hydraulic pressure, and a third side surface formed between the first side surface and the second side surface and having an inclined cross-section. When the overpressure prevention member is pushed toward the elastic member by the fluid, a corner portion at which the first side surface and the third side surface meet each other may enter the flow path, thereby reducing the area of the flow path. In an aspect, the overpressure prevention unit comprises: 1) a protruding portion extending outward from the conduit and defining an accommodation space in fluid communication with the flow path, 2) an overpres