Background technique
Electrochemical fuel cell is a kind of device that hydrogen fuel and oxygenant can be changed into electric energy and reaction product.The internal core parts of this device are membrane electrode (Membrane Electrode Assembly are called for short MEA), and membrane electrode (MEA) is made up of as carbon paper a PEM, two porous conductive materials of film two sides folder.The catalyzer that contains the initiation electrochemical reaction of even tiny dispersion on two interfaces of film and carbon paper is as the metal platinum catalyzer.The electronics that the membrane electrode both sides can will take place to generate in the electrochemical reaction process with conductive body is drawn by external circuit, constitutes current loop.
At the anode tap of membrane electrode, fuel can pass porosity diffusion material (carbon paper) by infiltration, and electrochemical reaction takes place on catalyst surface, lose electronics, form positive ion, positive ion can pass PEM by migration, arrives the other end cathode terminal of membrane electrode.At the cathode terminal of membrane electrode, contain the gas of oxygenant (as oxygen), as air, pass porosity diffusion material (carbon paper), and the generation electrochemical reaction obtains electronics on catalyst surface, forms negative ion by infiltration.The positive ion of coming in the negative ion and the anode tap migration of cathode terminal formation reacts, and forms reaction product.
Adopting hydrogen is fuel, and the air that contains oxygen is in the Proton Exchange Membrane Fuel Cells of oxygenant (or pure oxygen is an oxygenant), and fuel hydrogen has just produced hydrogen positive ion (or being proton) in the catalytic electrochemical reaction of positive column.PEM helps the hydrogen positive ion to move to the cathode region from the positive column.In addition, PEM is separated the air-flow and the oxygen containing air-flow of hydrogen fuel, they can not mixed mutually and produces explosion type reaction.
In the cathode region, oxygen obtains electronics on catalyst surface, forms negative ion, and moves the hydrogen positive ion reaction of coming, formation reaction product water with the positive column.In the Proton Exchange Membrane Fuel Cells that adopts hydrogen, air (oxygen), anode reaction and cathode reaction can be expressed in order to following equation:
Anode reaction: H
2→ 2H
++ 2e
Cathode reaction: 1/2O
2+ 2H
++ 2e → H
2O
In typical Proton Exchange Membrane Fuel Cells, membrane electrode (MEA) generally all is placed in the middle of the pole plate of two conductions, leads the surface that the membrane electrode plate contacts with membrane electrode for every and mills quarter by die casting, punching press or machinery, and formation is the guiding gutter of one or more at least.These lead the pole plate that the membrane electrode plate can be a metallic material, also can be the pole plates of graphite material.These lead positive column and cathode region that water conservancy diversion duct on the membrane electrode plate and guiding gutter import fuel and oxygenant the membrane electrode both sides respectively.In the structure of a Proton Exchange Membrane Fuel Cells monocel, only there is a membrane electrode, the membrane electrode both sides are respectively the guide plate of anode fuel and the guide plate of cathode oxidant.These guide plates are both as current collector plate, also as the mechanical support on membrane electrode both sides, guiding gutter on the guide plate acts as a fuel again and enters the passage of anode, cathode surface with oxygenant, and as the passage of taking away the water that generates in the fuel cell operation process.
In order to increase the total output of whole Proton Exchange Membrane Fuel Cells, two or more monocels can be connected into battery pack or be unified into battery pack by the mode that tiles usually by straight folded mode.In straight folded, in-line battery pack, can there be guiding gutter on the two sides of a pole plate, and wherein one side can be used as the anode guide face of a membrane electrode, and another side can be used as the cathode diversion face of another adjacent membranes electrode, and this pole plate is called bipolar plates.A series of monocel connects together by certain way and forms a battery pack.Battery pack tightens together by front end-plate, end plate and pull bar usually and becomes one.
A typical battery stack generally includes: the water conservancy diversion import and the guide channel of (1) fuel and oxidant gas are distributed to fuel (as hydrogen, methyl alcohol or the hydrogen-rich gas that obtained by methyl alcohol, rock gas, gasoline) and oxygenant (mainly being oxygen or air) in the guiding gutter of each anode, cathode plane equably after reforming; (2) import and export and the guide channel of cooling fluid (as water) are evenly distributed to cooling fluid in each battery pack inner cooling channel, the thermal absorption that hydrogen in the fuel cell, the exothermic reaction of oxygen electrochemistry are generated and take battery pack out of after dispel the heat; (3) outlet of fuel and oxidant gas and corresponding guide channel, fuel gas and oxidant gas are when discharging, and portability goes out the liquid that generates in the fuel cell, the water of steam state.Usually, the import and export of all fuel, oxygenant, cooling fluid are all opened on the end plate of fuel cell group or on two end plates.
Proton Exchange Membrane Fuel Cells can be used as the power system of launch vehicles such as all cars, ship, can make portable, portable, fixed electricity generating device again.
Proton Exchange Membrane Fuel Cells is generally with hydrogen or contain portly hydrogen or alcohols is made fuel.As car, ship power system or movable type, stationary power generation station the time, generally use air oxidant.
When used in proton exchange membrane fuel cell is done car, ship power system or movable type, stationary power generation station, must comprise battery pile, supply of fuel, air supply, cooling heat dissipation, control and electric energy output various piece automatically.Wherein air supply is essential.Electrochemical reaction in the Proton Exchange Membrane Fuel Cells improves along with the pressure of fuel, oxygenant air and accelerates.
So the pressure of air supply improves, the performance of fuel cell output electric energy can improve, and but then, to the device of fuel cell delivery air, also will consume energy greatly as air compressor, accounts for 5~20% of the total output of fuel cell greatly.In order to improve the integral energy efficient of whole fuel cell generation, the energy consumption that reduces air transport device is vital.
In addition, used PEM in the present proton exchange membrane fuel cell electrode, in the battery operation process, need water molecule and preserve moisture, arrive electrode cathode end participation electrochemical reaction from the electrode anode end because have only the proton of aquation just can freely pass PEM.Otherwise, when the air of a large amount of dryings when fuel cell is supplied, easily the moisture subband in the PEM is run, cause the electrode internal resistance sharply to increase, battery performance sharply descends.So in general need through humidification to the fuel cell air supplied, airborne moisture relative moisture improved, in order to avoid make the PEM dehydration.
The device that can be used for the conveying of Proton Exchange Membrane Fuel Cells power generation system air at present mainly contains following two classes:
(1) realizes the compressor of air compression by means of the variation of volume, for example scroll air compressor, screw air compressor, piston type air compressor.
(2) realize the air pump or the blower fan of air compression by means of the air of rapid movement, for example high pressure, middle pressure, low pressure blower, sliding vane air pump etc.
At present, first kind air compressor can realize that high-pressure air flows to fuel cell, generally can reach 1.5 to 5 barometric pressure (relative pressure), but this class air compressor is because air compression is bigger, the heat of compression is also bigger, cause the compressor power consumption bigger, performance improves though Proton Exchange Membrane Fuel Cells is because air pressure increases, and the energy conversion efficiency of whole fuel cell generation reduces on the contrary.
In order to reduce the power consumption of this class air compressor, at present often with the supporting coaxial thermal expansion machine of air compressor, the hot air of discharging in the fuel cell by the thermal expansion machine, is reached recovered energy, reduction integrated air consumption of compressor.The special air compressor for Proton Exchange Membrane Fuel Cells conveying air of the Vairex company of U.S. development at present utilizes top principle exactly, reaches low energy consumption, and working pressure can reach 5 barometric pressure (relative pressure).
The second class compressor air machinery is actually blower, this class pressurized air machinery can realize that also low pressure or middle pressure air flow to fuel cell, air pressure generally is no more than 1.5 barometric pressure (relative pressure), concerning general blower, air pressure is just lower, and working pressure is between 1~0.05 barometric pressure (relatively) generally.
First kind air compressor can realize that high pressure carries air to fuel cell, and can a supporting thermal expansion machine coaxial with air compressor, realizes reducing the integrated air consumption of compressor, but many shortcomings that are difficult to overcome are arranged:
(1) realize the compressor of air compression by means of the variation of volume, for example requirement on machining accuracy such as scroll air compressor, screw air compressor is very high, so cost is higher.
(2) realize high pressure when fuel cell is carried air, also very high to pipeline, joint, valve and control system requirement, so cost is also higher.
(3) realize high pressure when fuel cell is carried air, the danger of fuel cell operation increases greatly, and Security reduces.
(4) noise ratio is bigger.
The second class compressed air machine flows fast by air and realizes air compressor, as blower, air pump etc., can realize to fuel cell low pressure or middle pressure (working pressure is at 0.05~1.5 barometric pressure relative pressure), carries air, but shortcoming is also arranged:
(1) relative pressure low (0.05~1.5 barometric pressure) often when fuel cell is carried air, but air mass flow is big, be easy to the moisture subband in the PEM in the Proton Exchange Membrane Fuel Cells is run, cause the electrode internal resistance sharply to increase, battery performance sharply descends.
(2) though when fuel cell is carried air relative pressure low (0.05~1.5 barometric pressure) because flow is big, still high to the energy consumption of whole blower air delivery system.
Summary of the invention
Purpose of the present invention is exactly to provide a kind of blower fan that fuel cell is carried air that can be for the defective that overcomes above-mentioned prior art existence, and this blower fan cost is low, also has moistening function.
Purpose of the present invention can be achieved through the following technical solutions: a kind of blower fan that can be fuel cell conveying air, it is characterized in that, comprise draught fan impeller, the boosting impeller, separation membrane, housing, motor, described separation membrane is separated into left and right sides two-part with housing, left half at housing is provided with the boosting impeller, right half at housing is provided with draught fan impeller, be provided with motor in outside by draught fan impeller one side, described draught fan impeller, the boosting impeller is coaxial with the output shaft of motor, the bottom of the right half of described housing is provided with air intlet, its top is provided with can be for the air outlet slit that enters fuel cell, the bottom of the left half of described housing is provided with the wet air import of being discharged by fuel cell, and its top is provided with the evacuation port that communicates with atmosphere.
Also comprise an air filter, this air filter is located at the front of housing right half bottom air import.
Described separation membrane is the separation membrane of the airtight body molecule of permeable molecule only.
Described separation membrane is a macromolecule proton exchange membrane.
Described separation membrane is a polystyrolsulfon acid class PEM.
Compared with prior art, the present invention has the following advantages and effect:
(1) realizes that to fuel cell low-pressure delivery air, fuel cell operation pressure is low, pipeline, valve member are required low, various parts prices are reduced greatly.
(2) blower fan itself is made simply, and price is low.
(3) fuel cell operation pressure is low, and Security is good.
(4) air that enters fuel cell humidification can not cause the PEM dehydration of fuel cell.
(5) can reclaim the saturation water hot air energy that comes out in the fuel cell, whole fan energy consumption is reduced.
(6) running noises is low.
Embodiment
The invention will be further described below in conjunction with accompanying drawing.
As shown in Figure 1, a kind of blower fan that can be fuel cell conveying air, comprise draught fan impeller 1, boosting impeller 2, separation membrane 3, housing 4, motor 5, air filter 6, described separation membrane 3 is separated into left and right sides two-part with housing 4, left half at housing 4 is provided with boosting impeller 2, right half at housing 4 is provided with draught fan impeller 1, be provided with motor 5 in housing 4 outside draught fan impeller 1 one sides of leaning on, described draught fan impeller 1, boosting impeller 2 is coaxial with the output shaft of motor 5, the bottom of the right half of described housing 4 is provided with air intlet 7, its top is provided with can be for the air outlet slit 8 that enters fuel cell, described air filter 6 is located at the front of air intlet 7, air filters laggard air intlet 7 of going into blower fan through air filter 6, the bottom of the left half of described housing 4 is provided with the wet air import 9 of being discharged by fuel cell, and its top is provided with the evacuation port 10 that communicates with atmosphere.
As shown in Figure 2,
motor 5 high speed rotating drive draught fan impeller 1 fast rotational, air sucks blower fan through
air filter 6 and produces quick flow air stream from atmosphere, come out and enter Proton Exchange Membrane Fuel Cells from
blower fan outlet 8 from
fuel cell 11 air intlets, through producing a large amount of water and heat after the electrochemical reaction, become saturation water hot air and some water, export out from fuel battery air, enter
blower fan import 9 again, when these hot airs and water vapour and water pass boosting impeller 2 (Fig. 3), the impeller boosting is rotated, because
boosting impeller 2, draught fan impeller 1 and
motor 5 are all coaxial, therefore reduced the energy consumption of motor, to reach energy-conservation purpose.In addition,
boosting impeller 2 and draught fan impeller 1 can free permeable molecule by one but the
separation membrane 3 that cannot see through any gas molecule separate, what this film can E.I.Du Pont Company
PEM or other polystyrolsulfon acid class PEMs, this ion exchange membrane can allow the very fast diffusion of the moisture of saturated steam see through film, this simultaneously arrives draught fan impeller 1 (Fig. 4) from
boosting impeller 2, and with atmosphere in the dry air that the sucks air that is mixed into certain relative moisture enter fuel cell.The blower fan material comprises boosting
impeller 2, and the material of draught fan impeller 1 and main shaft all should be anticorrosive, the material that no ion produces, and as stainless steel, high performance engineering plastics, materials such as pottery.