KR-102962215-B1 - Apparatus for Controlling the Relative Humidity of Fuel Cell Unit

KR102962215B1KR 102962215 B1KR102962215 B1KR 102962215B1KR-102962215-B1

Abstract

The present invention relates to a humidity control device for a fuel cell unit. In one embodiment of the present invention, the humidity control device for a fuel cell unit comprises: a first fuel cell unit located relatively forward along the driving direction of a vehicle and including a first fuel cell stack, a first compressor that compresses air flowing into the first fuel cell stack, and a first humidifier located downstream of the compressor; a second fuel cell unit located relatively far away along the driving direction of a vehicle and including a second fuel cell stack, a second compressor that compresses air flowing into the second fuel cell stack, and a second humidifier located downstream of the compressor; and a device for determining the driving conditions of the first fuel cell unit and the second fuel cell unit, and in response to the driving conditions of the first fuel cell unit and the second fuel cell unit, the first fuel cell unit and the second fuel cell unit are at an optimal operating temperature. It includes a control unit that controls the humidity to drive.

Inventors

장인우
신성재

Assignees

현대자동차주식회사
기아 주식회사

Dates

Publication Date: 20260507
Application Date: 20210804

Claims (9)

A first fuel cell unit located relatively forward along the driving direction of a vehicle and including a first fuel cell stack, a first compressor for compressing air flowing into the first fuel cell stack, and a first humidifier located downstream of the first compressor; A second fuel cell unit located relatively far along the driving direction of the vehicle and including a second fuel cell stack, a second compressor for compressing air flowing into the second fuel cell stack, and a second humidifier located downstream of the second compressor; and A control unit that determines the driving conditions of the first fuel cell unit and the second fuel cell unit, and controls the humidity so that the first fuel cell unit and the second fuel cell unit are driven at an optimal operating temperature in response to the driving conditions of the first fuel cell unit and the driving conditions of the second fuel cell unit; The above driving conditions are a humidity control device for fuel cell units, including the driving temperature of each fuel cell unit.
In Article 1, A humidity control device for a fuel cell unit, wherein the first fuel cell unit further comprises a first bypass configured to bypass the first humidifier.
In Article 1, A humidity control device for a fuel cell unit, wherein the second fuel cell unit further comprises a second bypass configured to bypass the second humidifier.
In Article 1, The above control unit is a humidity control device for a fuel cell unit in which the operating point of the first fuel cell unit and the operating point of the second fuel cell unit are driven along the same humidity line in response to the driving conditions of the first fuel cell unit and the driving conditions of the second fuel cell unit.
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In Article 1, A humidity control device for a fuel cell unit configured such that the control unit controls the first fuel cell unit and the second fuel cell unit so that the operating point of the first fuel cell unit and the operating point of the second fuel cell unit are located on the same humidity line.
In Paragraph 6, A humidity control device for a fuel cell unit configured such that the above control unit controls a first humidifier and a second humidifier so that the humidification amount of the first fuel cell unit is lower than the humidification amount of the second fuel cell unit.
In Paragraph 6, The above control unit is a humidity control device for a fuel cell unit in which the driving pressure of the first fuel cell unit is controlled to be lower than the driving pressure of the second fuel cell unit.
In Paragraph 6, The above control unit is a humidity control device for a fuel cell unit in which the supply gas flow rate of the first fuel cell unit is controlled to be higher than the supply gas flow rate of the second fuel cell unit.

Description

Apparatus for Controlling the Relative Humidity of Fuel Cell Unit The present invention relates to a humidity control device for a fuel cell unit, and more preferably, to a humidity control device for a fuel cell unit for controlling the operation of a fuel cell unit to maintain the same humidity operating point between the fuel cell units in order to optimize the operation of a fuel cell unit located at the front, which is relatively close to the driving direction, and a fuel cell unit located at the rear, which is relatively close to the driving direction. In general, fuel cells are power generation systems that directly convert fuel energy into electrical energy, offering the advantages of low pollution and high efficiency. In particular, fuel cells are attracting attention as a next-generation energy source because they can generate electrical energy using energy sources such as petroleum, natural gas, and methanol, which are easy to store and transport. These fuel cells are classified into phosphoric acid, molten carbonate, solid oxide, polymer electrolyte, and alkaline fuel cells depending on the type of electrolyte used; while each of these fuel cells operates based on the same fundamental principle, they differ in the type of fuel used, operating temperature, catalyst, and electrolyte. Polymer electrolyte fuel cells are fuel cells that use a polymer membrane with hydrogen ion exchange properties as the electrolyte. Compared to other types of fuel cells, they possess high output characteristics with a high current density, a simple structure, fast start-up and response characteristics, and excellent durability. Furthermore, since they can use methanol or natural gas as fuel in addition to hydrogen, they are suitable for applications in various fields such as automotive power sources, distributed and on-site generators, military emergency power, and spacecraft power sources. A fuel cell stack basically includes a polymer electrolyte membrane and an anode electrode and a cathode electrode bonded to both sides of the electrolyte membrane. The electrolyte membrane, anode electrode, and cathode electrode constitute a unit cell called a so-called membrane-electrode assembly (MEA). To improve performance regarding electrochemical reactivity, ionic conductivity, electronic conductivity, fuel or oxidant transportability, byproduct transportability, and interfacial stability, it is desirable for the anode electrode and the cathode electrode to each include a platinum catalyst layer and a diffusion layer. Additionally, the fuel cell stack includes a bipolar plate installed between unit cells and a monopolar plate installed between one side of a unit cell and an end plate. These plates have electrical insulation properties, and a flow path for fuel supply is installed on one or both sides thereof. A stack of multiple unit cells and plates is fixed while being pressed by a pair of end plates and a fastening member. The operating principle of the fuel cell stack described above is as follows. First, when hydrogen is supplied to the anode electrode and oxygen or oxygen-containing air is supplied to the cathode electrode, the supplied hydrogen on the anode side is separated into electrons and hydrogen ions in the platinum catalyst layer; the electrons move along the external wire and the hydrogen ions move through the electrolyte membrane, after which oxygen, electrons, and hydrogen ions meet on the cathode side to produce water. At this time, electrical energy is obtained by the electrons moving through the external circuit. Recently, automobiles capable of driving through fuel cell stacks have emerged, and furthermore, development is being carried out on vehicles containing multiple fuel cell stacks to increase driving range and improve performance. However, regarding fuel cell stacks mounted at various locations, there was a problem in that the operating temperature of each fuel cell stack could differ depending on the driving wind, and the electrical energy efficiency generated could differ depending on the different driving temperatures. Furthermore, in the case of a vehicle that performs autonomous driving using a fuel cell stack, at least one fuel cell stack may be located in a position facing the vehicle's driving direction, so control is essential to maintain the same humidity level for optimal operation at the location of the fuel cell stack in the vehicle. FIG. 1 illustrates a perspective view of an automobile including a humidity control device for a fuel cell unit as an embodiment of the present invention. FIG. 2 illustrates a configuration diagram of a fuel cell unit as an embodiment of the present invention. FIG. 3 illustrates a configuration diagram of a fuel cell unit as another embodiment of the present invention. FIG. 4a illustrates a humidity curve according to operating pressure as an embodiment of the present invention. FIG. 4b illustrates a moisture content curve according to the supply gas fl