Background technology
Fuel cell is the device that a kind of chemical energy that produces can be with fuel and oxidant generation electrochemical reaction the time is transformed into electric energy.The core component of this device is membrane electrode (Membrane Electrode Assembly, be called for short MEA), membrane electrode can be made up of by conductive porous property diffusion material (as carbon paper) with two that are clipped in the film two sides a proton exchange membrane, is evenly distributed with the catalyst (as metal platinum) of the caused electrochemical reaction of tiny dispersion on two boundary faces that proton exchange membrane contacts with electric conducting material.Draw by external circuit with the electronics that conductive body will take place to produce in the electrochemical reaction process on the membrane electrode both sides, has just constituted current circuit.
Anode tap at membrane electrode, fuel can pass porousness diffusion material (as carbon paper) by infiltration, and in catalyst surface generation electrochemical reaction, loses electronics and form cation, cation can pass proton exchange membrane by migration, arrives the other end-cathode terminal of membrane electrode.Cathode terminal at membrane electrode, the gas (as air) that contains oxidant (as oxygen), pass porousness diffusion material (as carbon paper) by infiltration, and in catalyst surface generation electrochemical reaction, obtain electronics and form anion, this anion further combines with the cation of coming from the anode tap migration, forms product.
Be fuel with hydrogen, be in the Proton Exchange Membrane Fuel Cells of oxidant (or be oxidant with the pure oxygen) with the air that contains oxygen, fuel hydrogen loses the catalytic electrochemical reaction of electronics in the anode region, form hydrogen cation (proton), its electro-chemical reaction equations is:
Anode reaction: H
2→ 2H
++ 2e
Oxygen obtains the catalytic electrochemical reaction of electronics in the cathodic region, form anion, and this anion further combines with the hydrogen cation of coming from the anode tap migration, forms reaction product water.Its electro-chemical reaction equations is:
Cathode reaction: 1/2O
2+ 2H
++ 2e → H
2O
Proton exchange membrane in the fuel cell is except the proton that is used for taking place electrochemical reaction and migration exchange reaction and produces, its effect comprises that also air-flow that will contain fuel hydrogen and the air-flow that contains oxidant (oxygen) separate, and they can not mixed mutually and produces the explosion type reaction.
In typical Proton Exchange Membrane Fuel Cells, membrane electrode generally is placed between the pole plate of two conductions, all offers guiding gutter on the two-plate, therefore is called guide plate again.On the surface that guiding gutter is opened in membrane electrode contacts, mill formation at quarter by die casting, punching press or machinery, its quantity is at one or more.Guide plate can be made by metal material, also can be made by graphite material.The effect of the guiding gutter on the guide plate is anode region or the cathodic region that fuel or oxidant is imported the membrane electrode both sides respectively.In the structure of a Proton Exchange Membrane Fuel Cells monocell, only there are a membrane electrode and two guide plates, two guide plate branches are located at the membrane electrode both sides, a guide plate as anode fuel, another is as the guide plate of cathode oxidant.These two guide plates also are the mechanical support on membrane electrode both sides both as current collector plate.Guiding gutter on the guide plate is the passage that fuel or oxidant enter the male or female surface, also is the exhalant canal that the water that generates in the battery operation process is taken away.
In order to increase the power of Proton Exchange Membrane Fuel Cells, the composition battery pack that usually mode of two or more monocells by straight folded mode or tiling connected together, or be called battery pile.This battery pack tightens together by front end-plate, end plate and pull bar usually and becomes one.In battery pack, the two sides of the pole plate between two proton exchange membrane all is provided with guiding gutter, is called bipolar plates.The wherein one side of bipolar plates is as the anode guide face of a membrane electrode, and another side is then as the cathode diversion face of another adjacent membranes electrode.1), the import and the flow-guiding channel of fuel and oxidant gas a typical battery pack also comprises usually:.Its effect is that fuel (as hydrogen, methyl alcohol or the hydrogen-rich gas that obtained after reforming by methyl alcohol, natural gas, gasoline) and oxidant (mainly being oxygen or air) are distributed in the guiding gutter of each anode, cathode plane equably; 2), the import and export and the flow-guiding channel of cooling fluid (as water).Its effect is that cooling fluid is distributed in the cooling duct in each battery pack equably, absorbs the reaction heat that produces in the fuel cell and takes it out of battery pack and dispel the heat; 3), the outlet of fuel and oxidant gas and flow-guiding channel.Its effect is that the unnecessary fuel gas and the oxidant that do not participate in reaction are discharged, and will react the liquid state of generation or the water of gaseous state simultaneously and take out of.Above-mentioned fuel is imported and exported, oxidant is imported and exported and the import and export of cooling fluid all are opened on the end plate of fuel battery usually or be opened in respectively on two end plates.
Proton Exchange Membrane Fuel Cells can be used as the dynamical system of delivery vehicles such as car, ship, can be made into portable or fixed Blast Furnace Top Gas Recovery Turbine Unit (TRT) again.
When used in proton exchange membrane fuel cell is made the dynamical system of car, ship and portable or fixed Blast Furnace Top Gas Recovery Turbine Unit (TRT), must comprise battery pile, fuel hydrogen supply subsystem, air supply subsystem, cooling heat dissipation subsystem, automatic controls and electric energy outputting machine structure various piece.
Fig. 1 is the basic composition schematic diagram of fuel cell generation.Number in the figure, 1 is fuel cell pack, 2 are storage hydrogen bottle or other hydrogen-storing device, 3 is pressure-reducing valve, 4 is air filter, and 5 is the air compression feeding mechanism, and 6,6 ' is Water-vapor seperator, 7 is water tank, 8 is the cooling fluid circulating pump, and 9 is radiator, and 10 is the hydrogen circulating pump, 11,12 is humidifying device, and 13 is the hydrogen pressure maintaining valve.
In order to improve the energy conversion efficiency of fuel cell whole generating system, except the electrode performance that improves fuel cell, the hydrogen utilization ratio that improves fuel cell generation is extremely important.Hydrogen supply and recycling to improving the hydrogen utilization ratio of fuel cell generation, reaching the operation stability that guarantees fuel cell generation has key effect.Fuel hydrogen is through decompression, after the voltage stabilizing, and send out should for the oxidant generation electrochemistry that delivers into fuel cell pack and electrode opposite side through humidifying device again.Hydrogen supply one side at electrode is constantly carried out along with reacting, and can slowly produce water.These water are mainly from two aspects, and the one, the hydrogen behind the humidification carries a part of water and enters fuel cell pack, and after hydrogen reaction fell, water just stayed; Another part is to pass through the membrane electrode reverse osmosis to the electrode anode side at the water that the electrode cathode side is generated by electrochemical reaction.In order to take this two parts water out of fuel cell pack from the electrode anode side, must make hydrogen excessive to the hydrogen flowing quantity of fuel cell pack supply greater than 1.0 metering ratios, this two parts water is taken out of when leaving fuel cell pack by excessive hydrogen.
In order both to accomplish excessive hydrogen recycle can be used simultaneously, the water of hydrogen supply one side of electrode in the fuel cell pack can be taken out of again, the technology that adopts is to utilize the technology of hydrogen recycle pump or hydrogen recycle device at present.As shown in Figure 1, a steam trap 6 is set on the hydrogen outlet pipeline, a hydrogen recycle pump 10 is set between steam trap 6 and hydrogen inlet pipeline.By the hydrogen recycle pump excessive hydrogen is reclaimed, reenter fuel cell pack and participate in reaction, can take above-mentioned two part water out of fuel cell pack again simultaneously.As patented technology " the recycling device of a kind of fuel cell hydrogen of suitable low pressure operation ", China Patent No. is 03255444.3.
It is proper to single fuel cell pack that above-mentioned hydrogen recycle is utilized technology.But be applied to by a plurality of single fuel battery stack modules will go wrong when the large-scale fuel cell pack that integration mode constitutes.
In fact, fuel cell generation is used for the dynamical system of delivery vehicle or as the power station, all requires very high power output at present.This high power output requires fuel cell pack must realize high voltage, big electric current output.In order to realize powerful fuel cell pack, be necessary a plurality of single fuel battery stack modules are constituted big fuel cell pack compact on the volume through integration mode.For example the method for " US Patent5486430 " is arranged in parallel a plurality of single fuel cell packs, and the import of all air of each single fuel cell pack, hydrogen, cooling water, outlet be unified to be integrated on the shared front console or on the panel of rear end.Front console and rear end panel are provided with the six shared big fluid passages of import and export for all air on all single fuel cell packs, hydrogen, cooling fluid.The described method of the patent of Shenli Science and Technology Co Ltd, Shanghai " a kind of fuel cell of integrated form (patent No.: 02265512.3) " for example again, by the shared current-collecting panel of a plurality of fuel cell packs, the forward and backward integrated a plurality of fuel cell packs on this current-collecting panel.This current-collecting panel is arranged on the centre of a plurality of fuel cell packs, and the import and export of the air of all fuel cell packs, hydrogen, cooling fluid is all unified to be integrated on the shared current-collecting panel of this piece.This current-collecting panel is provided with the six shared big fluid passages of import and export for all air on all fuel cell packs, hydrogen, cooling fluid.
The above-mentioned integral type fuel battery of realizing by the whole bag of tricks, though shared each fluid passage of each fuel battery stack module, but each module all has the positive and negative flow-collection mother-board of oneself, connect by the positive and negative electrode motherboard on all fuel cell modules being carried out series and parallel, whole integral type fuel battery can be exported the high voltage that corresponds to actual needs, the requirement of big electric current.
Fuel cell generation to more high-power output, can pass through integrated more fuel battery stack module in principle, and allowing the import and export shared six big fluid passages of all air on all fuel battery stack modules, hydrogen, cooling fluid, the big fuel cell pack after promptly integrated is a kind of integral structure with six big fluid passages of total air, total hydrogen, total cooling fluid import and export equally.
In order to make integral type fuel battery have higher volume, weight, power density, integral type fuel battery front end current-collecting panel, rear end current-collecting panel or middle total current-collecting panel must be carried out the compactest engineering design, for example: US Patent 6159629, to a kind of integral type fuel battery front end current-collecting panel and rear end current-collecting panel, adopted a kind of water conservancy diversion deck structure manifold design, as Fig. 2, Fig. 3, shown in Figure 4.
Water conservancy diversion aspect manifold design technology on the above-mentioned integral type fuel battery current-collecting panel can allow the import and export shared six big fluid passages of all air on each fuel battery stack module, hydrogen, cooling fluid in the integral type fuel battery, each total fluid passage has constituted an aspect of current-collecting panel inside, and each aspect all has independent mozzle road junction to draw, and constitutes six big fluid flow ports of the total air of integral type fuel battery, total hydrogen, total cooling fluid import and export.
Though above-mentioned technology makes integral type fuel battery reach volume compact in design, improves the purpose of volumetric power density greatly, carrying out hydrogen fuel when recycling, have following technological deficiency:
1, every kind of fluid enters from the fluid flow port that always advances of integral type fuel battery current-collecting panel earlier, is full of earlier-individual aspect, is diverted to each fuel cell module again.In order to increase the integral type fuel battery volumetric power density, often the whole aspect of this total influent stream body passage formation is narrow, and each of each fuel cell module advances fluid flow port is not the area that has occupied whole aspect fully, but has only occupied the sub-fraction (as Fig. 3, Fig. 4, shown in Figure 5) of whole aspect.When total influent stream body fluid that is single phase, during as cooling fluid-water, be full of total influent stream body passage of whole streak aspect fully by fluid, divide into from each of each fuel cell module that fluid flow port enters then equably, can not produce any problem.But when two-phase flow regime that fluid is made up of most of gas, a small amount of liquid, gaseous fluid is easy to be full of total influent stream body passage of whole streak aspect, and can be equably divide into that fluid flow port enters at each of each fuel cell module, a small amount of fluid liquid (condensed water often) then can accumulate in total influent stream body passage of streak aspect, and after gathering a lot, tend to cause being assigned randomly in certain fuel cell module, the guiding gutter that causes gas phase to flow is full of aqueous water and stops up.
Above-mentioned situation always advancing in the hydrogen passage in integral type fuel battery often takes place, condensation goes out the small part aqueous water to hydrogen behind the humidification owing to change in flow and variations in temperature take place, after gathering a lot of water for a long time, easily with flow hydrogen gas, and cause in each fuel cell module in the hydrogen flow guide groove in certain or several monocells water blockoff takes place.Water blockoff can cause this monocell fuel hydrogen to be in starvation in certain monocell hydrogen flow guide groove, and voltage sharply descends, and can burn out this electrode when serious.
2, when hydrogen recycle use devices such as employing hydrogen recycle pump, for the water with hydrogen side in each fuel battery stack module in the whole integrated fuel cell pile brings out, must adopt very big hydrogen recycle pump or the hydrogen recycle use device of circular flow, the very big device of this global cycle hydrogen flow need consume very big power, reduced the generating efficiency of whole fuel cell generation, i.e. the conversion efficiency of fuel hydrogen.And the very big device of this global cycle hydrogen flow often occupied volumetric spaces very big in the whole fuel cell generation, and increased weight, and often noise is also bigger.
Summary of the invention
Be exactly purpose of the present invention provides a kind of integral type fuel battery to hydrogen access way and recycling optimal design in order to address the above problem, always it can avoid condensed water to accumulate in the hydrogen passage.
The object of the present invention is achieved like this: a kind of integral type fuel battery to hydrogen access way and recycling optimal design, comprise integrated fuel cell pile and the hydrogen recycle use device formed by at least two fuel battery stack modules, two ends at integrated fuel cell pile respectively are provided with the afflux end plates, or be provided with the afflux centre panel in the centre of integrated fuel cell pile, on afflux end plates or in the afflux centre panel, be provided with and always advance the hydrogen passage, each fuel battery stack module is respectively equipped with and props up hydrogen passage and expenditure hydrogen passage, the hydrogen recycle use device comprises hydrogen circulating pump and steam trap, is characterized in:
Described always to advance the hydrogen passage be a level and smooth pipeline, and it is horizontally set in the outside or afflux centre panel of afflux end plates, distributes a plurality of and advance the hydrogen passage and link to each other with a hydrogen inlet of each fuel battery stack module respectively by always entering hydrogen passage side;
The expenditure hydrogen passage of described each fuel battery stack module is directly drawn from another afflux end plates or afflux centre panel respectively;
Described hydrogen recycle use device also comprises a multifunctional electromagnetic valves, the import of each single valve is communicated with the expenditure hydrogen passage of each fuel battery stack module respectively in the multifunctional electromagnetic valves, and the outlet of each single valve is communicated with steam trap by a house steward respectively in the multifunctional electromagnetic valves.
Described each advance the effective drift diameter of hydrogen passage less than the effective drift diameter that always advances the hydrogen passage.
Each single valve in the described multifunctional electromagnetic valves can be distinguished conducting successively, realizes that the hydrogen fuel to each fuel battery stack module of batch (-type), pulsed circulates.
Described integrated fuel cell pile is made up of six fuel battery stack modules, and the multifunctional electromagnetic valves in the corresponding hydrogen recycle use device is combined by six single electromagnetically operated valves.
Described integrated fuel cell pile is made up of three fuel battery stack modules, and the multifunctional electromagnetic valves in the corresponding hydrogen recycle use device is combined by three single electromagnetically operated valves.
Described integrated fuel cell pile is made up of eight fuel battery stack modules, and the multifunctional electromagnetic valves in the corresponding hydrogen recycle use device is combined by eight single electromagnetically operated valves.
Described integrated fuel cell pile is made up of ten fuel battery stack modules, and the multifunctional electromagnetic valves in the corresponding hydrogen recycle use device is combined by ten single electromagnetically operated valves.
The present invention, makes it compared with prior art owing to adopted above-mentioned technical scheme the integral type fuel battery of hydrogen access way and recycling optimal design, has following advantage and good effect:
1, fuel hydrogen elder generation hydrogen channel that always advances of a smoothing regulation in afflux end plates or afflux centre panel flows into, the hydrogen channel that always advances of this smoothing regulation distributes several again and advances the hydrogen passage with hydrogen in each fuel cell module advances to link to each other, because each effective drift diameter that advances the hydrogen passage advances hydrogen channel than always little, like this, when the hydrogen behind the humidification enter always advance the hydrogen passage after, again when propping up the hydrogen corridor diversion to each fuel cell module, even also can't accumulate in always to advance in the hydrogen passage at the initial frozen state water that produces, can all in time take fuel cell out of by excessive hydrogen.
2, because the hydrogen recycle use device has been carried out optimal design, set up a multifunctional electromagnetic valves, directly be communicated with each expenditure hydrogen passage respectively by each single valve in the multifunctional electromagnetic valves, by each single valve conducting successively being realized the hydrogen fuel to each fuel battery stack module intermittent, pulsed circulates, only need to adopt the hydrogen recycle pump of a less hydrogen circular flow, and can take the water of hydrogen side in each fuel battery stack module more easily out of.In addition, owing to adopted the hydrogen recycle pump of less hydrogen circular flow, the beneficial effect that also has energy-conservation, noise reduction and take up space less.
Embodiment
Referring to Fig. 5, Fig. 6, Fig. 7.The present invention is to the integral type fuel battery of hydrogen access way and recycling optimal design, comprise that the integrated fuel cell pile of being made up of at least two fuel battery stack modules 1 is (as Fig. 5, shown in Figure 6) and hydrogen recycle use device (as shown in Figure 7), two ends at integrated fuel cell pile 1 respectively are provided with afflux end plates 101,102 (as shown in Figure 5), or be provided with afflux centre panel 103 (as shown in Figure 6) in the centre of integrated fuel cell pile, in the outside (as shown in Figure 5) of afflux end plates (as 101) or in afflux centre panel 103 (as shown in Figure 6) be provided with and always advance hydrogen path 10 4, tell a plurality of by the side of always advancing the hydrogen passage and advance hydrogen path 10 4a, 104b...... be communicated with the hydrogen inlet of each fuel battery stack module respectively, the expenditure hydrogen path 10 5a of each fuel battery stack module, 105b...... directly draw from another afflux end plates (as 102) or afflux centre panel 103 respectively, each advances the effective drift diameter of hydrogen passage less than the effective drift diameter that always advances the hydrogen passage.
Hydrogen recycle use device (referring to Fig. 7) comprises hydrogen circulating pump 10, steam trap 6 and multifunctional electromagnetic valves 14, the import of each single valve is communicated with the expenditure hydrogen passage of each fuel battery stack module respectively in the multifunctional electromagnetic valves, and the outlet of each single valve is communicated with steam trap by a house steward respectively in the multifunctional electromagnetic valves.Each single valve in the multifunctional electromagnetic valves can be distinguished conducting successively, realizes that the hydrogen fuel to each fuel battery stack module of batch (-type), pulsed circulates.
The primary structure of a kind of integral type fuel battery to hydrogen access way and recycling optimal design of the present invention forms and operation principle can be described further by following examples:
See also Fig. 8, integrated fuel cell pile 1 among one embodiment of a kind of integral type fuel battery to hydrogen access way and recycling optimal design of the present invention comprises six fuel battery stack modules, is provided with the multifunctional electromagnetic valves of being made up of six single electromagnetically operated valves 14 in the corresponding hydrogen recycle use device.Six shared afflux centre panel 103 of fuel battery stack module.The hydrogen path 10 4 that always advances from a circle flows into fuel hydrogen behind the humidification on afflux centre panel top, distribute again six with six fuel battery stack modules in hydrogen advance to link to each other advance hydrogen path 10 4a, 104b, 104c......, advance the hydrogen passage with what the fuel hydrogen behind the humidification evenly was diverted to six fuel battery stack modules; The expenditure hydrogen path 10 5a of each fuel battery stack module, 105b, 105c...... directly draw from afflux intermediate plate 104 separately respectively, and with combination solenoid valve 14 in the import of each single valve connect one to one.Other label among the figure, 2 are storage hydrogen bottle or other hydrogen-storing device, and 3 is pressure-reducing valve, and 6 is Water-vapor seperator, and 10 is the hydrogen circulating pump, and 11 is humidifying device, and 13 is the hydrogen pressure maintaining valve.
This integral type fuel battery rated output power is 70 kilowatts, the about 900 standard liters of hydrogen supply amount/minute, wherein press hydrogen metering than 1.2 operations, nearly 180 standard liters/minute excess hydrogen need loop back through the hydrogen recycle pump.If do not adopt the technical scheme of invention, need a circular flow and be 180 liters/minute systemic circulation flow hydrogen diaphragm pump, could satisfy the requirement of its internal circulating load.This pump consumed power is 600 watts, and noise weighs 15 kilograms up to 80 decibels.Because each fuel battery stack module adopts unification always to advance the hydrogen passage and always goes out the hydrogen passage, when the hydrogen circular flow reaches 180 liters/minute, the hydrogen circular flow of average each fuel battery stack module only is 30 liters/minute, and this circular flow often can't guarantee taking out of of hydrogen side water in each fuel battery stack module.
After adopting technique scheme of the present invention, only needing a circular flow is the hydrogen diaphragm pump of 90 liters/minute medium circular flow, just can satisfy the requirement of its internal circulating load.This pump consumed power only is 250 watts, and noise only is 60 decibels, and weight only is 3 kilograms.
When the integral type fuel battery rated output power is 70 kilowatt hours, the hydrogen supply amount be approximately 900 liters/minute, press hydrogen metering than 1.1 operations, wherein only 90 liters of/minute excess hydrogen loop back through the hydrogen recycle pumps.Owing to adopted technical scheme of the present invention, this integrated fuel cell pile is made up of six fuel battery stack modules, and the expenditure hydrogen passage of each module is drawn from the afflux centre panel respectively, and is connected respectively with six single electromagnetically operated valves in the multifunctional electromagnetic valves.This multifunctional electromagnetic valves is only opened an electromagnetically operated valve at any time, only make the hydrogen outlet of a fuel battery stack module have hydrogen to enter circulation, so the hydrogen recycle flow of each fuel battery stack module is up to 90 liters/minute, under big like this hydrogen recycle flow effect, the hydrogen side water in this module is easy to be taken out of fuel cell pack.
Each single valve in the multifunctional electromagnetic valves is opened by the permanent order circulation successively, the hydrogen recycle that causes each fuel battery stack module also is an intermittent pulse type, the effect of actual motion proves that the hydrogen recycle use device of this optimal design makes each fuel cell pack draining cleaner.And has advantage energy-conservation and the reduction noise.
The present invention can be made up of the fuel battery stack module of two above numbers the integrated fuel cell pile in the integral type fuel battery of hydrogen access way and recycling optimal design, for example 3,8,10 or the like, multifunctional electromagnetic valves in the corresponding hydrogen recycle use device also is made up of single electromagnetically operated valve of two above numbers, for example 3,8,10 or the like.