CN2768217Y

CN2768217Y - Fuel cell with anti-backfire function

Info

Publication number: CN2768217Y
Application number: CNU2005200393914U
Authority: CN
Inventors: 夏建伟; 胡里清
Original assignee: Shanghai Shen Li High Tech Co Ltd
Current assignee: Shanghai Shenli Technology Co Ltd
Priority date: 2005-02-01
Filing date: 2005-02-01
Publication date: 2006-03-29
Anticipated expiration: 2015-02-01

Abstract

The utility model relates to a fuel battery with anti-backfire function, which includes a fuel battery pile, a hydrogen storage apparatus, a hydrogen pressure reducing valve, a hydrogen humidifier, an out galvanic pile hydrogen water-vapor separator, a hydrogen cycle pump, an air filtration device, an air compression supply apparatus, an air humidifier, an out galvanic pile air water-vapor separator, a water tank, a coolant recycle pump, a radiator and a humidification hydrogen water-vapor separator. The humidification hydrogen water-vapor separator includes a housing, and at least one porosity metallic tube and one baffle plate are installed in the housing; one end of the humidification hydrogen water-vapor separator is connected with the outlet end of the hydrogen humidifier and the other end is connected with the hydrogen outlet end of the fuel battery pile. Compared with the prior art, the hydrogen water-vapor separator of the utility model not only can separate water vapor from the humidification hydrogen, but also possess the function of preventing hydrogen pipeline backfire.

Description

Fuel cell with anti-backfire function

Technical Field

The utility model relates to a fuel cell especially relates to a fuel cell with anti-backfire function.

Background

An electrochemical fuel cell is a device capable of converting hydrogen and an oxidant into electrical energy and reaction products. The inner core component of the device is a Membrane Electrode (MEA), which is composed of a proton exchange Membrane and two porous conductive materials sandwiched between two surfaces of the Membrane, such as carbon paper. The membrane contains a uniform and finely dispersed catalyst, such as a platinum metal catalyst, for initiating an electrochemical reaction at the interface between the membrane and the carbon paper. 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.

At the anode end of the membrane electrode, fuel can permeate through a porous diffusion material (carbon paper) and undergo electrochemical reaction on the surface of a catalyst to lose electrons to form positive ions, and the positive ions can pass through a proton exchange membrane through migration to reach the cathode end at the other end of the membrane electrode. At the cathode end of the membrane electrode, a gas containing an oxidant (e.g., oxygen), such as air, forms negative ions by permeating through a porous diffusion material (carbon paper) and electrochemically reacting on the surface of the catalyst to give electrons. The anions formed at the cathode end react with the positive ions transferred from the anode end to form reaction products.

In a pem fuel cell usinghydrogen as the fuel and oxygen-containing air as the oxidant (or pure oxygen as the oxidant), the catalytic electrochemical reaction of the fuel hydrogen in the anode region produces hydrogen cations (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 hydrogen positive ions transported from the anode region to produce water as a reaction product. In a proton exchange membrane fuel cell using hydrogen, air (oxygen), 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, a Membrane Electrode (MEA) is generally placed between two conductive plates, and the surface of each guide plate in contact with the MEA is die-cast, stamped, or mechanically milled to form at least one or more channels. The flow guide polar plates can be polar plates made of metal materials or polar plates made of graphite materials. The fluid pore channels and the diversion trenches on the diversion polar plates respectively guide the fuel and the oxidant into the anode area and the cathode area on two sides of the membrane electrode. In the structure of a single proton exchange membrane fuel cell, only one membrane electrode is present, and a guide plate of anode fuel and a guide plate of cathode oxidant are respectively arranged on two sides of the membrane electrode. The guide plates are used as current collector plates and mechanical supports at two sides of the membrane electrode, and the guide grooves on the guide plates are also 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 increase the total power of the whole proton exchange membrane fuel cell, two or more single cells can be connected in series to form a battery pack in a straight-stacked manner or connected in a flat-laid manner to form a battery pack. In the direct-stacking and serial-type battery pack, two surfaces of one polar plate can be provided with flow guide grooves, wherein one surface can be used as an anode flow guide surface of one membrane electrode, and the other surface can be used as a cathode flow guide surface of another adjacent membrane electrode, and the polar plate is called a bipolar plate. A series of cells are connected together in a manner to form a battery pack. The battery pack is generally fastened together into one body by a front end plate, a rear end plate and a tie rod.

A typical battery pack generally includes: (1) the fuel (such as hydrogen, methanol or hydrogen-rich gas obtained by reforming methanol, natural gas and gasoline) and the oxidant (mainly oxygen or air) are uniformly distributed in the diversion trenches of the anode surface and the cathode surface; (2) the inlet and outlet of cooling fluid (such as water) and the flow guide channel uniformly distribute the cooling fluid into the cooling channels in each battery pack, and the heat generated by the electrochemical exothermic reaction of hydrogen and oxygen in the fuel cell is absorbed and taken out of the battery pack for heat dissipation; (3) the outlets of the fuel gas and the oxidant gas and the corresponding flow guide channels can carry out liquid and vapor water generated inthe fuel cell when the fuel gas and the oxidant gas are discharged. Typically, all fuel, oxidant, and cooling fluid inlets and outlets are provided in one or both end plates of the fuel cell stack.

The proton exchange membrane fuel cell can be used as a power system of vehicles, ships and other vehicles, and can also be used as a movable and fixed power generation device.

When the proton exchange membrane fuel cell can be used as a vehicle power system, a ship power system or a mobile and fixed power station, the proton exchange membrane fuel cell must comprise a cell stack, a fuel hydrogen supply system, an air supply subsystem, a cooling and heat dissipation subsystem, an automatic control part and an electric energy output part.

Fig. 1 is a fuel cell power generation system, in fig. 1, 1 is a fuel cell stack, 2 is a hydrogen storage bottle or other hydrogen storage device, 3 is a pressure reducing valve, 4 is an air filtering device, and 5 is an air compression supply device; 6. the hydrogen and air separator 6' is the water-steam separator of the galvanic pile, 7 is the water tank, 8 is the cooling fluid circulating pump, 9 is the radiator, 10 is the hydrogen circulating pump, 11, 12 are the hydrogen and air humidifying device.

The operation of the fuel cell requires the humidification of the hydrogen side to ensure the normal operation of the fuel cell. Because of the distance between the hydrogen-side humidifier of the fuel cell and the hydrogen-side inlet of the fuel cell, water drops are separated out of the gas flow, and the collision of the water drops can generate larger water drops, even a water mass is suspended in the gas flow. Such large water droplets or water masses suspended in the air stream, which once entered the fuel cell stack, have a fatal effect on the performance of the electrodes in the stack, as shown in fig. 2, must be removed. Hydrogen, on the other hand, is a high energy fuel, but also a very highly flammable gas. The problem of backfire prevention must be considered because the backfire may occur when the hydrogen gas in the pipeline is mixed with air and exposed to an open fire, which may cause fuel explosion in the entire hydrogen storage cylinder.

SUMMERY OF THE UTILITY MODEL

The present invention is directed to overcome the above-mentioned drawbacks of the prior art and to provide a fuel cell with an anti-backfire function, which can prevent the humidified hydrogen gas entering the fuel cell stack to react from containing liquid substances, thereby improving the operation stability of the fuel cell.

The purpose of the utility model can be realized through the following technical scheme: a fuel cell with anti-backfire function comprises a fuel cell stack, a hydrogen storage device, a hydrogen pressure reducing valve, a hydrogen humidifying device, a stack-outlet hydrogen water-vapor separator, a hydrogen circulating pump, an air filtering device, an air compression supply device, an air humidifying device, a stack-outlet air water-vapor separator, a water tank, a cooling fluid circulating pump and a radiator.

The number of the porous metal tubes is three.

The porous metal pipe is a porous stainless steel pipe.

The humidifying hydrogen gas water-vapor separator is vertically arranged, the partition plate is arranged at the middle upper part of the inner cavity of the separator shell, the partition plate divides the inner cavity of the shell into an upper cavity and a lower cavity, at least one hole corresponding to the porous metal tube is formed in the partition plate, the porous metal tube is in butt joint with the partition plate hole in the lower cavity, one end of the porous metal tube is an opening, the other end of the porous metal tube is a closed structure, the lower side part of the lower cavity is provided with a humidifying hydrogen gas inlet, the bottom of the lower cavity is provided with a water outlet, and the top of the upper cavity is provided with a wet hydrogen gas outlet.

The water outlet extends upwards to form an inverted horn shape, and the water outlet is provided with a normally closed electromagnetic valve for controlling timed discharge.

The shell is cylindrical.

The shell and the partition board are made of stainless steel materials, and the temperature for melting and blocking the propagation of hydrogen flame is not higher than 250 ℃.

As shown in figure 3, the utility model adopts a special material-porous stainless steel tube. The material can separate water from hydrogen, when the gas flow enters the humidifying hydrogen water-vapor separator, the hydrogen can diffuse into the humidifying hydrogen water-vapor separator through the porous stainless steel pipe and come out from the wet hydrogen outlet at the other end of the separator, and the water molecules are blocked by the special material and discharged through the water outlet at the bottom, thus achieving the purpose of water-vapor separation. And the water-vapor separator also has the function of preventing backfire, once the mixed air in the hydrogen pipeline in the fuel cell stack is ignited by open fire, the fire can rapidly spread along the hydrogen in the pipeline, when the mixed air reaches the water-vapor separator, the porous stainless steel pipe can be immediately sintered and blocked when meeting hydrogen flame, and the flame is blocked, so that the function of preventing the mixed air from being backfired into a gas storage tank which stores a large amount of hydrogen is achieved. Therefore, the utility model is called as a fuel cell with anti-backfire function.

Drawings

FIG. 1 is a schematic diagram of a conventional fuel cell;

FIG. 2 is a schematic diagram of the formation of water droplets and suspended water clusters in the conduit between the outlet of the hydrogen humidifier and the hydrogen inlet of the fuel cell stack in a prior art fuel cell;

fig. 3 is a schematic structural diagram of the humidified hydrogen gas-water-vapor separator of the fuel cell of the present invention.

Detailed Description

The present invention will be further explained with reference to the accompanying drawings.

Examples

As shown in fig. 3, a fuel cell with anti-backfire function comprises a fuel cell stack 1, a hydrogen storage device 2, a hydrogen pressure reducing valve 3, an air filtering device 4, an air compression supply device 5, a stack-outlet hydrogen water-vapor separator 6, a stack-outlet air water-vapor separator 6', a water tank 7, a cooling fluid circulating pump 8, a radiator 9, a hydrogen circulating pump 10, a hydrogen humidifying device 11, an air humidifying device 12 and a humidifying hydrogen water-vapor separator 13, wherein the humidifying hydrogen water-vapor separator comprises a stainless steel shell 131, three (hydrogen) gas permeable and water impermeable porous stainless steel pipes 132 and a stainless steel partition 133 are arranged in the shell 131, and the shell 131 is cylindrical.

The humidifying hydrogen gas water-vapor separator 13 is vertically arranged, the clapboard 133 is arranged at the middle upper part of the inner cavity of the separator shell, the clapboard 133 divides the inner cavity of the shell into an upper cavity and a lower cavity, three holes 134 corresponding to the porous stainless steel tube 132 are arranged on the clapboard 133, the porous stainless steel tube 132 is butted with the clapboard holes 134 at the lower cavity, the upper end of the porous stainless steel tube 132 is open, the lower end is closed, the lower side part of the lower cavity is provided with a humidifying hydrogen gas inlet 135, the bottom is provided with an inverted horn-shaped water outlet 136, and the top of the upper cavity is provided with a wet hydrogen gas outlet 137.

As shown in fig. 3 and with reference to fig. 1, the humidified hydrogen gas water-vapor separator 13 has one end communicating with the outlet end of the hydrogen humidifying device 11 and the other end communicating with the hydrogen inlet end of the fuel cell stack 1.

As shown in fig. 3 and fig. 1 and fig. 2, in this embodiment, after passing through a section of pipe 121, the humidified hydrogen gas coming out from the outlet end of the hydrogen humidifying device 11 in the 50kw fuel cell engine inevitably condenses some water droplets 122 or suspended water mass 123, and after the humidified hydrogen gas enters the humidified hydrogen gas inlet 135 of the humidified hydrogen gas-steam separator 13 of the present invention, the humidified hydrogen gas can diffuse into the humidified hydrogen gas through the porous stainless steel pipe 132 and come out from the humidified hydrogen gas outlet 137 at the other end of the partition plate 133, immediately enters the hydrogen gas inlet of the fuel cell stack 1 to participate in the reaction, and water molecules are blocked by the special material, and are periodically controlled to open and discharge through the water outlet 136 arranged at the bottom and a normally closed electromagnetic valve 138, so as to achieve the purpose of water-steamseparation. Moreover, the water-vapor separator 13 of this embodiment also has a function of preventing backfire, so that once the mixed air in the hydrogen pipeline of the fuel cell stack 1 is ignited by an open fire, the fire will rapidly spread along the hydrogen in the pipeline, and when reaching the water-vapor separator 13, the water-vapor separator 13 can play a role of preventing backfire due to the sintering flame-retardant function of the porous stainless steel pipe 132.

In this embodiment, three porous stainless steel tubes 132 are used, and the inner diameter of the porous stainless steel tube 132 is 2cm and the length thereof is 10 cm; by analogy, according to the difference of the flow rate of the humidified hydrogen to be treated, one, two or even a plurality of porous stainless steel tubes 132 may be adopted, and the shell 131 and the partition 133 may also be made of other materials, so as to derive more embodiments, which are all the protection scope of the present invention.

Claims

1. A fuel cell with anti-backfire function comprises a fuel cell stack, a hydrogen storage device, a hydrogen pressure reducing valve, a hydrogen humidifying device, a stack-outlet hydrogen water-vapor separator, a hydrogen circulating pump, an air filtering device, an air compression supply device, an air humidifying device, a stack-outlet air water-vapor separator, a water tank, a cooling fluid circulating pump and a radiator.

2. The fuel cell with the function of preventing the back fire according to claim 1, wherein the number of the porous metal tubes is three.

3. The fuel cell with the function of preventing the back fire according to claim 1 or 2, wherein the porous metal tube is a porous stainless steel tube.

4. The fuel cell of claim 1, wherein the humidified hydrogen-water-vapor separator is vertically disposed, the separator is disposed at the middle upper portion of the inner cavity of the separator housing, the separator divides the inner cavity of the housing into an upper chamber and a lower chamber, the separator is provided with at least one hole corresponding to the porous metal tube, the porous metal tube is in butt joint with the separator hole at the lower chamber, the porous metal tube has an open end at one end and a closed end at the other end, the lower side portion of the lower chamber is provided with a humidified hydrogen inlet, the bottom portion of the lower chamber is provided with a water outlet, and the top portion of the upper chamber is provided with a wet hydrogen outlet.

5. The fuel cell with the function of preventing the back fire as claimed in claim 4, wherein the water outlet extends upwards to form an inverted horn shape, and the water outlet is provided with a normally closed solenoid valve for controlling the timed discharge.

6. The fuel cell with an anti-backfire function as claimed in claim 1, wherein said case is cylindrical.