CN2904317Y - Fuel cell generating system - Google Patents

Abstract

The utility model discloses a fuel cell power system, including a fuel cell stack comprising of a plurality of single cells, a hydrogen supplying device, an air supplying device, an electric control device and an oxygen enrichment device on the air pipe from the air supplying device to the fuel cell stack. The utility model can improve the oxygen concentration in the air entering into the fuel cell and is good for improving the power density of the fuel cell.

Description

Fuel cell power generation system

Technical Field

The utility model relates to a fuel cell power generation system.

Background

A fuel cell is a power generation device that can directly convert chemical energy into electrical energy. The fuel cell, especially the proton exchange membrane fuel cell, has the advantages of no pollution, low noise, no corrosion, quick start, easy preparation, high power density, high power generation efficiency, long service life and the like in power generation, thereby having wide application prospect in the fields of vehicles, power generation equipment, military, aerospace and the like.

The proton exchange membrane fuel cell mainly comprises a plurality of monocells, wherein each monocell comprises two gas flow field plates and a membrane electrode. The membrane electrode is sandwiched between two gas flow field plates. The electrons generated in the electrochemical reaction process can be led out by conductive objects at two sides of the membrane electrode through an external circuit to form a current loop.

In a pem fuel cell using hydrogen as the fuel and oxygen-containing air as the oxidant, the catalytic electrochemical reaction of the fuel hydrogen in the anode region produces positive hydrogen ions (or protons). The proton exchange membrane assists the migration of positive hydrogen ions from the anode region to the cathode region. In addition, the proton exchange membrane separates the hydrogen-containing fuel gas stream from the oxygen-containing gas stream so that they do not mix with each other to cause explosive reactions.

In the cathode region, oxygen gains electrons on the catalyst surface, forming negative ions, which react with the positive ions transported from the anode region to produce water as a reaction product. In a proton exchange membrane fuel cell using hydrogen and air, the anode reaction and the cathode reaction can be expressed by the following equations:

and (3) anode reaction:

and (3) cathode reaction:

in a typical pem fuel cell, the membrane electrode is typically placed between two electrically conductive flow field plates, and the surface of each flow field plate in contact with the membrane electrode is die-cast, stamped, or mechanically milled to form at least one flow channel. These flow field plates may be metallic or graphite materials. The flow field plates are used as current collecting plates and mechanical supports at two sides of the membrane electrode, and the flow channels can also be used as channels for fuel and oxidant to enter the surfaces of the anode and the cathode and as channels for taking away water generated in the operation process of the fuel cell.

In order to make the pem fuel cell operate in a high performance state, it is necessary to ensure that enough oxygen participates in the electrochemical reaction, otherwise, the fuel cell will have a voltage drop due to insufficient oxygen, even a negative pressure, and the fuel cell will fail. For this reason, an increase in the supply pressure of air or a higher degree of overfeeding is generally employed. However, the high-pressure air supply increases the cost of the system and increases the difficulty of system sealing, and once hydrogen or air is temporarily short of air, the pressure difference between two sides of the proton exchange membrane is large, and the proton exchange membrane is easy to deform or even break. The air is excessively supplied to a higher degree, so that the gas flow velocity in the flow channel is increased, the water generated by the reaction is easily taken awayby the air, the water shortage phenomenon of the proton exchange membrane occurs, and the power generation performance of the fuel cell is influenced.

Disclosure of Invention

The utility model provides a fuel cell power generation system, it can provide the oxygen of higher concentration for fuel cell, improves the space utilization of air runner to reduce required air flow, make proton exchange membrane fuel cell be in high performance's operating condition.

The utility model discloses can realize through following technical scheme: a fuel cell power generation system comprises a fuel cell pack consisting of a plurality of single cells, a hydrogen supply device, an air supply device and an electric control device, and is further provided with an oxygen enrichment device which is arranged on an air supply pipeline leading from the air supply device to the fuel cell pack.

In the utility model, the oxygen enrichment device is an oxygen enrichment membrane component; the fuel cell stack is a proton exchange membrane fuel cell stack.

The utility model discloses owing to adopted above technical scheme, the oxygen boosting device is an oxygen boosting membrane module, and the oxygen boosting membrane module can become two parts gas with the air separation, and partly oxygen boosting gas, oxygen concentration can reach 30%, and partly is low oxygen concentration's rich nitrogen gas. Therefore, the oxygen partial pressure in the air entering the fuel cell is greatly improved, the diffusion of reaction gas into an electrode layer is facilitated, the reaction efficiency is improved, and the power generation performance and the power generation efficiency of the fuel cell can be effectively improved.

The present invention will be further described with referenceto the accompanying drawings and the following detailed description.

Drawings

FIG. 1 is a block diagram of the present invention

Detailed Description

According to the illustration of fig. 1, a fuel cell power generation system, which comprises a fuel cell stack composed of a plurality of single cells, a hydrogen supply device, an air supply device and an electrical control device, is further provided with an oxygen enrichment device, which is arranged on an air supply pipeline of the air supply device leading to the fuel cell stack. The oxygen enrichment device is an oxygen enrichment membrane component which can separate air into two parts of gas, wherein the oxygen concentration of one part of oxygen enrichment gas can reach 30 percent, the other part of oxygen enrichment gas is nitrogen enrichment gas with low oxygen concentration, and the oxygen enrichment gas is introduced into an air flow channel of a flow field plate of the fuel cell.

The fuel battery pack is a proton exchange membrane fuel battery pack, has no pollution and low noise during power generation, and also has the advantages of no corrosion, quick start, easy preparation, high power density, high power generation efficiency, long service life and the like.

Claims (3)

1. A fuel cell power generation system comprising a fuel cell stack composed of a plurality of unit cells, a hydrogen gas supply device, an air supply device, and an electric control device, characterized in that: the fuel cell power generation system is also provided with an oxygen enrichment device which is arranged on an air supply pipeline of the air supply device leading to the fuel cell set.

2. The fuel cell power generation system according to claim 1, wherein the oxygen enrichment means is an oxygen enrichment membrane module.

3. A fuel cell power generation system according to claim 1 or 2, characterized in that the fuel cell stack is a proton exchange membrane fuel cell stack.