CN210489740U

CN210489740U - Proton exchange membrane fuel cell purging device

Info

Publication number: CN210489740U
Application number: CN201921511128.9U
Authority: CN
Inventors: 杨彦博; 马天才; 戚佳鑫; 丛铭; 魏学哲; 余卓平
Original assignee: Tongji University
Current assignee: Tongji University
Priority date: 2019-09-11
Filing date: 2019-09-11
Publication date: 2020-05-08
Anticipated expiration: 2029-09-11

Abstract

The utility model relates to a proton exchange membrane fuel cell sweeps device, including fuel cell stack (1), air unit and hydrogen unit, the air unit is connected with negative pole (10) of fuel cell stack (1), the hydrogen unit is connected with positive pole (11) of stack, air unit and hydrogen unit connection. Compared with the prior art, the structure is simple, the existing equipment is utilized to reduce the occurrence of carbon oxidation, and for a fuel cell engine automobile, the fuel cell system does not add any accessory equipment, and the volume and the mass of the battery system do not need to be increased.

Description

Proton exchange membrane fuel cell purging device

Technical Field

The utility model belongs to the technical field of proton exchange membrane fuel cell technique and specifically relates to a proton exchange membrane fuel cell sweeps device is related to.

Background

Proton exchange membrane fuel cells use hydrogen and air as reactants to generate electricity and water. The method has high conversion efficiency, no pollution and zero emission, and is the development direction of vehicle-mounted energy in the future. At present, various automobile companies and scientific research institutions in the world are dedicated to developing proton exchange membrane fuel cell automobiles, so that the problem of durability of the proton exchange membrane fuel cell automobiles can be solved, and the proton exchange membrane fuel cell automobile development method has important significance for industrialization of the fuel cell automobiles. The longer the life of the membrane electrode assembly, a key material of the pem fuel cell, the better the durability of the fuel cell. However, when the fuel cell is started and purged, the electrode potential of the cathode oxygen is high, so that a microcircuit is easily formed with the carbon carrier, and an electrochemical cell is established at the cathode of the fuel cell, so that the carbon carrier at the cathode side is oxidized, and the structure of the cathode catalyst is permanently degraded. Therefore, other methods must be taken to reduce carbon corrosion and improve the durability of the fuel cell.

In order to improve the durability of the fuel cell, a three-phase reaction interface inside the membrane electrode is usually designed in an optimized manner, and the common design scheme includes Pt alloying treatment, Pt surface modification treatment, methods of taking carbon nano materials and conductive ceramics as catalyst carriers, adding tungsten carbide in the middle layer of the catalyst, and the like. However, the above method not only greatly increases the cost of the fuel cell system, but also cannot avoid carbon damage of the fuel cell during the start-up process. Currently, in order to prevent the membrane electrode assembly from being corroded during the starting process of the fuel cell system, nitrogen is generally used for purging the fuel cell, but the method needs additional accessories, and has the problems of increasing the volume and the mass of the fuel cell system, affecting the moving performance of the fuel cell system and increasing the additional cost of the fuel cell system.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a proton exchange membrane fuel cell purging device for overcoming the defects of the prior art.

The purpose of the utility model can be realized through the following technical scheme:

a proton exchange membrane fuel cell purging device comprises a fuel cell stack, an air unit and a hydrogen unit, wherein the air unit is connected with a cathode of the fuel cell stack, the hydrogen unit is connected with an anode of the fuel cell stack, and the air unit is connected with the hydrogen unit.

The air unit is connected with the hydrogen unit through a first one-way valve, and an outlet of the first one-way valve is connected with the air unit.

The first check valve is a straight-through first check valve or a right-angle first check valve.

The outlet of the first one-way valve is connected with the air unit through a first mass flow controller.

The air unit comprises an air inlet subunit, the air inlet subunit comprises an air filter, an air pump, a second one-way valve and a second mass flow controller which are sequentially connected, the second mass flow controller is connected with the inlet of the cathode, and the hydrogen unit is connected between the inlet of the cathode and the second mass flow controller.

The air inlet subunit comprises a first pressure sensor, and the first pressure sensor is connected between the air compressor and the second one-way valve.

The hydrogen unit comprises a hydrogen inlet subunit, the hydrogen inlet subunit comprises a hydrogen storage tank, a pressure reducing valve, a third one-way valve and a third mass flow controller which are sequentially connected, and the third mass flow controller is connected with an inlet of the anode.

The hydrogen unit include hydrogen discharge subunit, hydrogen discharge subunit include with the exit linkage's of positive pole hydrogen circulating pump, the hydrogen circulating pump connect the first tie point between third check valve and relief pressure valve, the air unit is connected in the second tie point between third check valve and the tie point.

The hydrogen inlet subunit comprises a second pressure sensor connected between the first connection point and the second connection point.

Compared with the prior art, the utility model has the advantages of it is following:

(1) the structure is simple, the air unit is connected with the hydrogen unit, hydrogen-air mixed gas can be introduced into the cathode, the existing equipment is utilized to reduce the occurrence of carbon oxidation, for a fuel cell engine automobile, no additional equipment is added to a fuel cell system, and the volume and the mass of the battery system are not required to be increased.

(2) The cost is low, carbon corrosion of a membrane electrode assembly is reduced by utilizing the catalytic reaction of hydrogen-air mixed gas at the cathode of the fuel cell, the durability of the fuel cell can be improved by using a small amount of hydrogen and air, and the required cost is low.

(3) After the hydrogen-air mixed gas is introduced into the cathode of the fuel cell stack, the hydrogen can relieve the corrosion of carbon, meanwhile, part of the hydrogen and the oxygen are subjected to catalytic reaction to generate water and heat, and the part of the heat can provide heat for the low-temperature cold start of the fuel cell, so that the hydrogen-air mixed gas can be compatibly applied to the start of the fuel cell in the environment below zero, and the success of the quick cold start of the fuel cell is assisted.

Drawings

Fig. 1 is a schematic structural view of the present invention;

reference numerals:

1 is a fuel cell stack; 2 is a first one-way valve; 3 is a first mass flow controller; 4 is an air filter; 5 is an air pump; 6 is a second one-way valve; 7 is a second mass flow controller; 8 is a hydrogen storage tank; 9 is a pressure reducing valve; 10 is a cathode; 11 is an anode; 12 is a third one-way valve; 13 is a third mass flow controller; 14 is a hydrogen circulating pump; 15 is a first pressure sensor; and 16 is a second pressure sensor.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.

Examples

The embodiment provides a proton exchange membrane fuel cell purging device, which comprises a fuel cell stack 1, an air unit and a hydrogen unit, wherein the air unit is connected with a cathode 10 of the fuel cell stack 1, the hydrogen unit is connected with an anode 11 of the fuel cell stack, and the air unit is connected with the hydrogen unit; the structure is simple, the existing equipment is utilized to reduce the occurrence of carbon oxidation, and for a fuel cell engine automobile, the fuel cell system does not need to be added with any accessory equipment, and the volume and the mass of the fuel cell system do not need to be increased.

The air unit is connected with the hydrogen unit through a first one-way valve 2, and an outlet of the first one-way valve 2 is connected with the air unit.

The first check valve 2 is a straight-through first check valve or a right-angle first check valve.

The outlet of the first non return valve 2 is connected to the air unit via a first mass flow controller 3.

The air unit comprises an air inlet subunit, the air inlet subunit comprises an air filter 4, an air pump 5, a second one-way valve 6 and a second mass flow controller 7 which are sequentially connected, the second mass flow controller 7 is connected with an inlet of the cathode 10, and the hydrogen unit is connected between the inlet of the cathode 10 and the second mass flow controller 7.

The air intake subunit comprises a first pressure sensor 15, the first pressure sensor 15 being connected between the air compressor and the second one-way valve 6.

The hydrogen unit comprises a hydrogen inlet subunit, the hydrogen inlet subunit comprises a hydrogen storage tank 8, a pressure reducing valve 9, a third one-way valve 12 and a third mass flow controller 13 which are sequentially connected, and the third mass flow controller 13 is connected with an inlet of the anode 11.

The hydrogen unit includes hydrogen discharge subunit, and hydrogen discharge subunit includes the hydrogen circulating pump 14 with the exit linkage of positive pole 11, and hydrogen circulating pump 14 is connected in the first tie point between third check valve 12 and relief pressure valve 9, and the air unit is connected in the second tie point between third check valve 12 and the tie point.

The hydrogen inlet sub-unit comprises a second pressure sensor 16, the second pressure sensor 16 being connected between the first connection point and the second connection point.

When in work, the following steps are executed:

step S1: introducing the hydrogen-air mixed gas into a cathode 10 of the fuel cell stack 1, and introducing the hydrogen into an anode 11 of the fuel cell stack 1;

step S2: the fuel cell stack 1 is connected with a load and the fuel cell stack 1 is subjected to a pulling load operation, so that the voltage of a single plate of the fuel cell stack 1 is reduced to 0.8V (after the voltage of the single plate is reduced to 0.8V, the carbon corrosion of a cathode 10 is weakened);

step S3: closing the one-way valve 2, and stopping introducing the hydrogen-air mixed gas into the cathode 10 of the fuel cell stack 1;

step S4: the reactant gas is normally introduced into the fuel cell stack 1 to make the fuel cell stack 1 operate normally, i.e. hydrogen is introduced into the anode 11 of the fuel cell stack 1 and air is introduced into the cathode 10 of the fuel cell stack 1.

In this embodiment, the hydrogen-air mixed gas is kept introduced for 30s before the fuel cell stack 1 is connected to the load, and after the fuel cell stack 1 is connected to the load and the voltage of the single plate is reduced to 0.8V, the check valve 2 is closed, and the reactant gas is normally introduced into the fuel cell stack 1.

At the cathode 10, because the oxidation potential of hydrogen is lower than that of carbon, hydrogen participates in oxidation on the membrane electrode catalyst first, so that the corrosion of carbon is reduced, and the durability of the fuel cell stack 1 is effectively improved; the volume content of the hydrogen can be 4% of that of the hydrogen-air mixed gas, the volume content of the air can be 96% of that of the hydrogen-air mixed gas, and the combustion limit of the hydrogen is 4.0-75.6% (volume concentration), and based on the consideration, the hydrogen does not combust with the oxygen when the volume concentration is lower than 4%; the flow rate of the hydrogen-air mixed gas is determined according to the power of the fuel cell stack 1; the carbon corrosion of the membrane electrode assembly is reduced by utilizing the catalytic reaction of the hydrogen-air mixed gas at the cathode 10 of the fuel cell stack 1, the durability of the fuel cell can be improved by using a small amount of hydrogen and air, and the required cost is low.

The embodiment can greatly prolong the service life of the proton exchange membrane fuel cell, improve the durability of the membrane electrode assembly on the premise of not increasing the volume and the quality of a fuel cell system, improve the moving performance of the fuel cell system, reduce the cost and the additional cost, and has important significance for promoting the industrialized development of the fuel cell.

Claims

1. A proton exchange membrane fuel cell purging device comprises a fuel cell stack (1), an air unit and a hydrogen unit, wherein the air unit is connected with a cathode (10) of the fuel cell stack (1), the hydrogen unit is connected with an anode (11) of the fuel cell stack, and the proton exchange membrane fuel cell purging device is characterized in that the air unit is connected with the hydrogen unit.

2. A proton exchange membrane fuel cell purging device as claimed in claim 1, wherein the air unit and the hydrogen unit are connected through a first one-way valve (2), and an outlet of the first one-way valve (2) is connected with the air unit.

3. A proton exchange membrane fuel cell purging device as claimed in claim 2, wherein the first check valve (2) is a straight-through first check valve or a right-angle first check valve.

4. A pem fuel cell purge apparatus as claimed in claim 2, wherein the outlet of said first check valve (2) is connected to the air unit through the first mass flow controller (3).

5. A proton exchange membrane fuel cell purge apparatus as claimed in claim 1, wherein the air unit comprises an air inlet sub-unit, the air inlet sub-unit comprises an air filter (4), an air pump (5), a second one-way valve (6) and a second mass flow controller (7) connected in sequence, the second mass flow controller (7) is connected with the inlet of the cathode (10), and the hydrogen unit is connected between the inlet of the cathode (10) and the second mass flow controller (7).

6. A PEMFC purge device according to claim 5 characterised in that said air intake subunit comprises a first pressure sensor (15), said first pressure sensor (15) being connected between the air compressor and the second check valve (6).

7. A proton exchange membrane fuel cell purging device as claimed in claim 1, wherein the hydrogen unit comprises a hydrogen inlet subunit, the hydrogen inlet subunit comprises a hydrogen storage tank (8), a pressure reducing valve (9), a third check valve (12) and a third mass flow controller (13) which are connected in sequence, and the third mass flow controller (13) is connected with an inlet of the anode (11).

8. A proton exchange membrane fuel cell purge apparatus as claimed in claim 7, wherein the hydrogen unit comprises a hydrogen exhaust sub-unit comprising a hydrogen circulation pump (14) connected to the outlet of the anode (11), the hydrogen circulation pump (14) being connected to a first connection point between the third check valve (12) and the pressure reducing valve (9), and the air unit being connected to a second connection point between the third check valve (12) and the connection point.

9. A pem fuel cell purge apparatus as claimed in claim 8, wherein said hydrogen admission subunit comprises a second pressure sensor (16), said second pressure sensor (16) being connected between said first connection point and said second connection point.