Abstract: proton exchange membrane fuel cell (PEMFC) structure, principles, characteristics and application of PEMFC focuses on the study of the status quo on the basis of which to explore the development trend of the PEMFC.
Key words: proton exchange membrane fuel cell; bipolar plate; electrode; catalyst
Key words: F30, China: A Article ID: 1672 3198 (2008) 04 0296 02
1 proton exchange membrane fuel cell structure and principle
In accordance with the different electrolyte fuel cell can be divided into phosphoric acid fuel cells, alkaline fuel cells, solid oxide fuel cell, molten carbonate fuel cells and proton exchange membrane fuel cell (PEMFC), and other five categories. PEMFC batteries from a single proton exchange membrane, gas diffusion electrodes, bipolar plates, etc., a map of its structure and working principle diagram. dell g5266 battery
PEMFC the basic process is as follows:
(1) on-board hydrogen through the bipolar Gas channel to reach the sony pcga-bp2r battery anode, hydrogen molecules in the catalyst under the dissociation of hydrogen ions and electrons to form;
(2) hydrogen ion hydration to proton H + (xH2O) in the form of electrolyte membrane to reach through the cathode, anode in the electronic side of the accumulation;
(3) oxygen through the bipolar plate to reach the cathode, oxygen molecules in the catalyst of oxygen ions into the next, overcast, between the anode a potential difference;
(4) anode and the cathode through the toshiba pa2487u battery outer circuit linking the anode in the build-up of electronic circuits will be outside the reach through the cathode to form a current load of homework. At the same time, in the cathode side to form water;
(5) as long as the continuous delivery of gas, PEMFC will be able to work in a row, to provide external power.
2 proton exchange membrane fuel cell characteristics
(1) efficient. PEMFC to electrochemical energy conversion method, there is no combustion process, free from restrictions Carnot cycle, the theoretical thermal efficiency of up to 85-90%, the actual efficiency of the internal combustion engine is about twice as much. Traditional sources of ibm thinkpad t60 battery power in order to improve the efficiency of the load will be limited to a small, but almost all of PEMFC load range of both high efficiency.
(2) modular. PEMFC in the modular structure has the characteristics according to different needs motive force combination of installation, the “Block”-style approach simplifies the design of different sizes of the stack design and manufacturing process.
(3) High reliability. As the PEMFC stack of modular design, simple structure, easy to maintain. Once a single cell of the problem and automatically take appropriate measures to shield will only make the system a slight decrease in output power and would not lead to the paralysis of the entire power hp f4809a battery system.
(4) fuel diversity. PEMFC power systems for the Hydrogen fuel can also be re-gas as fuel. The source of hydrogen can be a product of the electrolysis of water, it could be a gasoline, diesel, dimethyl ether, and other types of fossil fuel re-engineering the product. The hydrogen storage methods can be a high-pressure cylinders, liquid hydrogen, metal hydride, and so on.
(5), environment-friendly. Hydrogen, when used as fuel, PEMFC is the only product of the water, can be zero emissions. So as to restructure the gas for fuel, compared with the internal combustion engine, emissions are greatly reduced. In addition, PEMFC noise levels are very low, the structure of the apple a1012 battery parts can be recycled.
3 Research
3.1 The key components
Electrolyte membranes, bipolar plates, gas diffusion electrodes and catalysts is the proton exchange membrane fuel cell of the four key components.
Electrolyte membrane is a core component of the PEMFC, it has a direct impact on the performance of fuel cells and life. DuPont of the United States in 1962 the successful development of toshiba pa3107u-1brs battery perfluorinated acid proton-exchange membrane, the beginning of 1966 for the fuel cell, its business model Na fion, is still widely used. However, due to high cost of Nafion membrane, scientists are studying some of the fluoride or fluoride proton exchange membrane.
PEMFC bipolar plate in support play, set flow, split with the oxidant in the gas guide Reductant and apple m8244 battery with electrodes on the surface flows, the current graphite is widely used as materials in its guidance on the processing flow of gas flow Field, the basic flow in the form of snake-like, parallel, and cross-refers to the grid and so on.
Platinum-based catalysts is the best performance of the electrode catalyst for enhancing the utilization, with platinum nano-particles dispersed in the form of high-Supported to the conductive, corrosion-resistant body of Tam, Tam is currently widely used for the body of acetylene black, the surface area of about To 250m2 / g, the average size of 30nm.
PEMFC gas diffusion electrode by a two-tier structure, for a supporting role in the diffusion layer, another layer for the electrochemical reaction of the hp f3172a battery catalyst layer place. Selection of the general diffusion layer of carbon-carbon material such as graphite or carbon paper cloth preparation, should have high porosity and appropriate distribution of holes, no corrosion or degradation. According to the preparation and different thickness, the catalyst layer is divided into thick layer of hydrophobic, hydrophilic thin and ultra-thin three types. ibm thinkpad t40 battery
3.2 Control System
PEMFC performance by a variety of factors (temperature, pressure, etc.), in order to ensure normal operation of the PEMFC, to improve its reliability and effectiveness, it is necessary to monitor the impact of various factors. That the use of effective measures to continuously monitor the operation of the PEMFC important or critical condition, and collected the necessary information analysis and processing in order to ensure timely diagnosis and fault forecast for the PEM FC management system to provide a basis. At present, the test system for PEMFC-related research institutions and large companies, but has not yet worked out the relevant international standards for testing PEMFC and the corresponding standard test equipment, but the practical test system sony pcga-bp2v battery has been put into use. Canada’s Hydrogenics fuel cell test station (FCATS). U.S. Arbin’s integrated fuel cell test system (FCTS) is one of the prominent representatives of the.
4 proton exchange membrane fuel cell applications
Proton exchange membrane fuel cell is useful in a variety of fuel cells with higher levels of a class. Its superiority is not limited to high-energy conversion efficiency, low operating temperature, but also can be reflected in its large current density, more suitable for the start of the frequent occasions. Therefore, the world’s major car manufacturers optimistic about their consistency in the application of the auto industry, PEMFC has become today’s fuel cell vehicles of the main driving force for development. Currently, General Motors, Toyota, such as the world’s leading automotive companies, are actively to the development of PEMFC system for the dell d5318 battery power source of PEMFC electric vehicles, has launched various types of car-like, and PEMFC electric model to run the team. PEMFC electric vehicles for its outstanding performance and little environmental pollution and so on feature attracted widespread attention, even in the 21st century that will be the internal combustion engine vehicle of the most powerful competitors. hp pp2182d battery
In addition, in aerospace in particular in the field of unmanned air vehicles, as well as domestic power, distributed power, mobile electronic power equipment, underwater robot submarine and do not rely on air power forward, it is also a broad prospect.
5 proton exchange membrane fuel cell development trend
The key components in the area around the electrolyte membrane, catalyst and the bipolar plate research in the ascendant. Perfluorinated acid-expensive film, the development of the F-low-cost proton exchange membrane is the direction of future research. In recent years, a new type of proton exchange membrane of the research is to develop more than 100 ℃ in the use of high-temperature electrolyte membrane. In the catalyst, the development of ibm fru 08k8193 battery high-performance anti-electrode catalyst for CO poisoning is the most urgent task, should also look for non-precious metals or carbon nitride as a substitute for the existing platinum catalyst. At present, the widespread use of graphite plate has good corrosion resistance and high thermal conductivity, but the high cost, difficult process, strength, electrical conductivity and are not recyclable and metal plates. Metal plates is an urgent need to address the problem of toshiba PA3399U-1BRS battery surface treatment is to improve its corrosion resistance. Two-stage composite plate is a combination of pure graphite sheet metal plates and the advantages with corrosion-resistant. Small size. The quality of light. Technology-intensive and good characteristics such as the future development of the situation.
In the stack, future research will focus on the pile so that the electric apple a1148 battery unit close to the performance of a single battery performance, which need to stack to optimize the structure to ensure that every piece of battery power reactor units of the whole area of activity In a consistent operating environment and optimize the water, heat management, to improve the current density distribution uniformity.
References
[1] Li Xinghu. Introduction of electric vehicles [M]. Beijing: Beijing Institute of Technology Press ,2005:9-22.
[2] Min. Proton exchange membrane fuel cell stack electrical performance test research [J]. Power Technology, 2007,31 (5) :361-363
Archive for October, 2008
Motherboard battery failure
The laptop battery is dead motherboard cause of computer failure can not be started, see dell battery.
A telephone rings, I awakened from a dream that a friend’s computer problem: press the power button, the computer and nothing happens repeatedly press the power switch is still invalid. After my initial analysis, is likely to be part of the problem of power is not enough power (power of low-grade “patent”) is a short-circuit switch, Collect a variety of tools for a pretty good idea after a friend went straight home.
Indeed, such as friends above, no matter how pressing the power switch (socket and verify that there is good access to electricity), the computer just like wood, like the “one drop of a hat.” Computer does not have any alarm sound, the motherboard does not seem to load the required voltage, power supply fan is not moving, it appears that the computer simply will not be able to power up. Open the chassis closer look at the motherboard and power supply connections and there is nothing abnormal, the power switch is also not short-circuit signs readily connect to other parts again still boot failure.
As the power of “suspects” the greatest, I have decided to replace the method used to verify, just-on-hand to have a 250W power supply, installed after the computer is still “silent”; Is this 250W power supply is Li dell latitude d520 battery, dell latitude d600 battery, dell latitude d610 battery? At this time I noted the chassis installed in the four IDE devices: two hard drives and two CD-ROM. Friends said that just to upgrade, it appears that is likely to be caused by excessive power supply, two of which I immediately unplug the power plug of equipment, try to boot, the computer has not the slightest reaction.
While I am prepared to give up when suddenly the computer’s power supply fan spinning up, then heard the sound of the hard drive self-test, the display is also slowly changing light, the computer launched! But soon, start interrupting, showing “CMOS Load Failure”, and prompted by the “F2″ key to start, according to “Del” to enter the BIOS settings, no matter, I press the F2 key to enable the system to continue to guide, but in any case can not enter the Windows XP desktop, had to restart. The press “Del” key to enter the BIOS settings, friends trying to enter a password, but directly to the, and found the time to view positioned at 0:00 on January 1, 1999, and it is clear the CMOS gd761, td347, dell inspiron 6400 battery is dead . Immediately bought a new battery into one, and all equipment connected to the boot again, the smooth startup of the computer, but still showed “CMOS Load Failure”, had no choice but to enter the BIOS settings to choose “Load BIOS SAFE DEFAULTS” and restart the smooth into the Windows XP desktop, and all the restoration unabated. In the thought that the problem has been resolved, the friends suddenly find missing floppy drive icon, the system did not identify the floppy! Is just now beginning to think that the song might touch the floppy drive connection, so no choice but to open the case more thin, but still can not see the boot floppy. Calm down, just recall the operation “Load BIOS SAFE DEFAULTS”, the floppy drive is set to the default “None”, and restart to enter the BIOS settings, was to prove my idea to come back immediately, with a floppy drive while .
Recalling the whole process, everything is small CMOS battery to blame, it seems that analysis can not be in accordance with the experience of walking, but should be adaptable, to deal with the specific environment; as to why no power CMOS, the computer can start suddenly, Although my analysis may be connected to power after the computer does not start, but the power supply has power to the motherboard, the motherboard CMOS battery to be sufficient dell inspiron e1505 battery, dell inspiron 6400 battery power to start the computer, they have taken place in front of the scene.
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