Social basic energy as a vehicle fuel path and efficiency

<

The utilization path and efficiency of vehicle fuels With the continuous growth of the world economy, the number of automobiles is increasing, and the fuel consumption of automobiles is also increasing, accelerating the depletion of petroleum resources, and the tail gas of automobile emissions has caused serious atmospheric pollution. Although a number of breakthroughs have been made technically in the development of clean fuel vehicles for alternative fuels, the use of energy as a substitute for fuel is a crucial issue. Shows the path and efficiency of social basic energy for automotive fuels.

This kind of electrochemical reaction is totally different from the violent combustion reaction of hydrogen in oxygen. As long as the anode continuously inputs hydrogen and the cathode continuously inputs oxygen, the electrochemical reaction will continue continuously, and e2 will continue to flow through the external circuit. Electricity is formed so that the car is continuously powered. The principle of power generation is different from that of the traditional rotary cutting machine, which uses electric conductors to cut the magnetic lines of force. This electrochemical reaction is a static electricity generation method that obtains electricity without objects moving. Therefore, the fuel cell has the advantages of high efficiency, low noise, no pollutant emissions, etc. This ensures that the FCV becomes a truly efficient, clean automotive fuel cell body structure diagram. In order to meet the automotive use requirements, the vehicle fuel cell must also have High specific energy, low operating temperature, fast start-up, no leakage and other characteristics, in many types of fuel cells, the proton exchange membrane fuel cell (PEMFC) fully possesses these characteristics, so FCV uses fuel cells are all PEMFC.

The pure hydrogen fuel cell has a simple structure, high power generation efficiency, good startability and responsiveness, and does not require an on-board fuel reforming system. However, the establishment of such a social infrastructure for the hydrogenation of automobiles requires huge investment. It takes a long time to resolve many related problems. Therefore, a practical and feasible solution to the hydrogen supply of hydrogen hydrogen fuel cells for vehicles is to Filling station made on the spot. At present, in-situ hydrogen generation equipment using natural gas, LPG, and methanol as raw materials has been successfully developed and put on the market. Its hydrogen production capacity is 10 to 100 m3/h. Typical hydrogen-based fuels (natural gas, LPG) are used as raw materials. The Hydrogen Filling Station Principle Flow of Hydrogen Production. The hydrogen production capacity of the device is designed. The hydrogen compressor diaphragm compressor is compressed into a hydrogen storage tank after being compressed to 40 MPa in three stages. The total volume of the storage tank is 217 m3. The hydrogen filling machine can double-charge the gas. Divided into two pressure levels of 25MPa and 30MPa, it can refuel 5 cars and 1 bus in 10 minutes. Although the in-situ hydrogen production technology of gas filling stations has been successfully developed and utilized, the energy storage density of compressed hydrogen at 25 MPa and 30 MPa is far from that of vehicle fuels, resulting in the fact that hydrogen hydrogen fuel cell vehicles have not reached the current driving distance. The distance of the fuel car. To increase the hydrogen energy storage density, either increase the hydrogen storage pressure further to 70 MPa or liquefy the hydrogen. However, the former has large compression power consumption, and the vehicle-mounted hydrogen storage tank is heavy, which increases the weight of the output power of the unit. At the same time, there is no standard for using 70 MPa high-pressure hydrogen in terms of safety in use, resulting in the industry not dare to act rashly; and the latter needs to cool the hydrogen to -253 °C, ie, ultra-low temperature liquefaction of 20 °K, there are also many problems to be solved in the filling and on-board systems involving such extremely low temperatures. Therefore, the current use of compressed hydrogen fuel cells of 25 MPa and 30 MPa is more realistic.

Although liquid hydrogen fuel cells have such outstanding advantages, many specific problems involving liquid hydrogen are difficult to solve in the short term, and have not been widely applied in the automotive industry. Vehicle-mounted reforming fuel cell vehicle As the vehicle is small in size and space is limited, the installation of hydrogen purification equipment (system) is very complicated. In order to simplify the on-board reforming system, measures are taken to directly use the hydrogen-containing reforming gas in the fuel cell. Taking into account the car's hydrogen content and portability requirements for reforming fuels, essentially methanol is used for vehicle-mounted reforming fuels. The reaction equation of the steam reforming reaction is that the reaction is an endothermic reaction and the reaction temperature is about 300° C. The reaction equation of the partial oxidation reforming reaction is: the reaction is an exothermic reaction and the reaction temperature is about 600° C. From the point of view of reforming efficiency, the efficiency of steam reforming is higher than that of partial oxidation reforming, so it is desirable to adopt a steam reforming method. However, PEMFC basically starts at room temperature and the steam reforming reaction is an endothermic reaction. Therefore, the use of steam reforming requires the addition of a startup temperature raising system, which increases the complexity of the system. The partial oxidation reforming reaction is an exothermic reaction and can be started without the need for a temperature rise system. In order to simplify the steam reforming system, an autothermal reforming method combining steam reforming and partial oxidation reforming has been developed. That is, the partial oxidation reforming method is adopted when the automobile is started, and the purpose thereof is to increase the temperature of the reformer. When the temperature is raised to a desired height, it is automatically converted to a steam reforming method. Methanol steam reforming process The methanol reforming fuel cell uses hydrogen (at the anode) platinum (catalyst, platinum catalyst surface will be poisoned due to CO adsorption, lose its activity. To prevent platinum catalyst poisoning, on the one hand in the process Adoption of aqueous conversion selective oxidation and removal of CO from the reformed gas by means of hydrogen permeation membrane to prevent CO passage etc. On the other hand, addition of metallic lutetium (Lu) to the platinum catalyst to enhance the CO resistance of the platinum catalyst and ensure the reformer Maintaining high efficiency.Car methanol fuel cell methanol reforming process.

Car Methanol Fuel Cell Methanol Reforming Process 413 On-board Methanol Reforming Fuel Cell Vehicle Development Status The vehicle fuel for on-board methanol fuel cells is rich in hydrogen reforming gas rather than pure hydrogen, and therefore affects the responsiveness of the load. However, after the efforts of car manufacturers, this issue has been a breakthrough, such as the NECAR3 type of vehicle-mounted methanol reformer vehicle produced by Daimler-Benz, which shows that the response time of the load has reached 2 seconds. Level, this is a big improvement.

In the actual operation of the car, the car is required to have good startability and responsiveness. Therefore, in order to improve the car's startability and responsiveness, a battery is added to the car as auxiliary power, so that the methanol reformed fuel cell car becomes a hybrid electric car. In 1997, Daimler-Bentz Automotive transformed the A-type sedan into a methanol-reforming fuel cell vehicle. The Ballaed company produced a fuel cell stack installed under the front seat of the vehicle. The methanol storage tank and the reformer It was installed under the back seat of the car and the number of car occupants was reduced from the original 4 to 2 people. The vehicle is equipped with 40kg of methanol and a mileage of 400km. GM introduced a methanol-reforming fuel cell vehicle based on an EV1 vehicle in 1998. The fuel cell stack consists of three batteries with a capacity of 10kW and an output power of 30kW. ,The other is equipped with buffer battery. The methanol-reforming fuel cell vehicle that the European Union has promoted jointly developed by many companies will use the fuel cell power as the power source when operating under low load or normal load, and use the battery power when accelerating the high load. Japanese auto companies such as Toyota and Nissan also developed and launched methanol reformed fuel cell vehicles, which are hybrid electric vehicles. Although major automakers around the world have developed and launched methanol-reforming fuel cell vehicles since the 1990s, the effects are not ideal. Because of the simultaneous installation of a reforming system and batteries, the following problems have been overcome: Due to the complexity of the system, the driving operation is not as easy as a normal fuel-powered car; the reforming device occupies a limited space in the car body and affects the exterior design of the car; it increases the self-weight of the car, thereby increasing the fuel consumption. The above-mentioned inadequacy resulted in the obstruction of its practical application. In this case, direct methanol fuel cell vehicles emerged as the times require.

Direct Methanol Fuel Cell Vehicle The direct methanol fuel cell (DMFC) directs methanol into the cell, allowing methanol to reform directly on the anode electrode to generate hydrogen ions, electrons, and CO2. Its anode reaction is comparable to that of a methanol-reforming fuel cell. Since the methanol reformer is not provided, the DMFC system is simplified, load responsiveness is improved, and the total thermal efficiency of the fuel cell is greatly improved due to no heat loss of the reformer. The advantages are many. However, compared with the pure hydrogen fuel cell, there is a low activity of methanol, and the reaction speed of the fuel cell vehicle development is low. As a result, the voltage and current output density of the DMFC is lower. The United States Department of Energy (DOE) research study on DMFC and battery voltage and current density. To overcome the defect of DMFC, it is necessary to increase the reactivity of methanol, that is, to increase the battery operating temperature in order to speed up the electrochemical reaction. To do this, it is necessary to increase the heat resistance of the proton exchange membrane; to increase the amount of platinum catalyst to accelerate the reaction rate, It is bound to increase the cost of the DMFC itself, and it must also overcome the problem of methanol permeating the proton exchange membrane. Since there are no methanol reformers, many obstacles affecting the practical application of on-board methanol fuel cells have been eliminated, and car manufacturers have shown great interest in DMFCs. They are working closely with university research institutions on methanol activity and reactions. Research on related issues such as low speeds is looking forward to breakthroughs. Concluding remarks For methanol, natural gas and gasoline on-board refueling, the entire energy efficiency assessment from the fuel production well to the vehicle wheel can clearly show that methanol has the lowest overall efficiency and should not be selected for on-vehicle reforming fuel. However, both natural gas and gasoline reforming temperatures affect the startability and load response of the system. Natural gas is also inconvenient to carry fuel, and the fuel storage system plus the large size of the reforming system, taking up the vehicle's effective space and many other shortcomings; gasoline, although the fuel is easy to carry, but the H / C ratio is low, and contains olefins, aromatics and other double bond structure of hydrocarbons The class, therefore, will cause carbon to precipitate out of the carbon during the temperature reforming process, resulting in the loss of activity of the catalyst and at the same time a large amount of CO generated by the reforming process, thereby increasing the load of the converter and the volume of the reactor. The overall efficiency of natural gas and gasoline for on-vehicle reforming fuels is high, but it is more difficult than using methanol and there are more problems to be solved. Therefore, methanol is almost always used for on-vehicle reforming fuels. Whether it is to evaluate the overall energy efficiency of the basic fuels in today's society, or to evaluate them in terms of cleanliness and environmental protection, the most ideal and most suitable non-hydrogen fuel for automotive alternative fuels is none other than.

The pure hydrogen fueled proton exchange membrane pure hydrogen fuel cell has the advantages of mature technology, high efficiency, small volume and good load response, and is very suitable for use as an automotive fuel cell. For pure hydrogen fuel cell vehicles, although it cannot be said that they are perfect, there are no technical problems that hinder the practical application of HFCs. However, to popularize H22PEM2FC in the automotive industry, it is necessary to have a set of hydrogen for H22FCV. The social infrastructure is the same as gas stations in urban and rural areas. To build such a system, there are still great difficulties. This requires the unremitting efforts of the government, enterprises, and research institutions to achieve, but with the breakthrough in the difficulty of hydrogen storage and transportation technology and the depletion of oil resources, I believe this The process will be greatly accelerated.

Stringing machine

Stringing machine, stringing machines, Electronic Tennis Stringing machines, racket stringing machine

Yi He Technology (Shenzhen) Co.,Ltd , https://www.ballshootmachines.com