Please teach the master: analyze the development of new energy technology in the automobile how to write a paper?

Li Banner Automobile Manufacturing Network With the world energy crisis and environmental issues increasingly prominent, the automotive industry is facing a serious challenge. On the one hand, the shortage of petroleum resources, automobile is a large fuel consumption, and the current thermal efficiency of the internal combustion engine is low, fuel combustion of the heat generated by only about 35% -40% for the actual car driving, the rising car ownership exacerbated this contradiction; on the other hand, the large number of automobile use exacerbated the environmental pollution, the city's atmosphere of 82% of the CO, 48% of the NOx, 58% of the HC and micronutrient pollution. , 58% of HC and 8% of particles from automobile exhaust, in addition, a large amount of CO2 emissions from automobiles exacerbate the greenhouse effect, and automobile noise is one of the main elements of environmental noise pollution. China as an oil importer and the second largest oil-consuming country, pollution is serious, the World Bank identified the 20 most polluted cities 16 in China. The level of domestic automobile products and foreign countries is a big gap, the average fuel consumption is 10-30% higher, emissions are about 15-20 times, the automobile industry is facing more pressure.

Since the end of the last century the world's countries and major automobile companies, as well as major domestic research institutions and institutions of higher learning have been committed to the development of clean and energy-saving vehicles, new energy vehicles have gained significant development. Gasoline and diesel is the traditional internal combustion engine automobile energy, the use of other energy sources to provide steam power of the car can be called new energy vehicles. New energy sources currently under development include natural gas, liquefied petroleum gas, alcohols, dimethyl ether, hydrogen, synthetic fuels, biogas, air, and charge fuel cells.

This paper presents an overview of the development of new energy vehicle technology and gives an opinion on its development prospects.

1 Types of New Energy Vehicles and Their Characteristics

1.1 Natural Gas Vehicles and Liquefied Petroleum Gas Vehicles

Natural gas vehicles, also known as "blue-powered" vehicles, are mainly fueled by compressed natural gas (CNG), liquefied natural gas (LNG) and adsorbed natural gas (ANG). Compressed Natural Gas Vehicles (CNGV) are the most common. Liquefied Petroleum Gas Vehicle (LPGV) is fueled by liquefied petroleum gas (LPG), CNG and LPG are ideal ignition engine fuels, with a single gas composition, high purity, uniform mixing with air, complete combustion, low CO and particulate emissions, low combustion temperature and thus low NOx emissions, superior rare combustion characteristics, low temperature starting and low temperature operation performance. The disadvantage is that the storage and transportation performance is worse than that of liquid fuels, the volumetric efficiency of the engine is lower, and the ignition delay period is longer. Both types of vehicles tend to use dual-fuel systems, i.e., a gasoline or diesel fuel system and a compressed natural gas (CNG) or liquefied petroleum gas (LPG) system, where the vehicle can be driven by either system and can be easily transitioned from one system to the other. Cummins and the U.S. Department of Energy are working together to develop a new generation of natural gas engines called "Advanced Reciprocating Engine System (ARES)", which, according to the development goals, will have a thermal efficiency of 50% (more than 80% in the case of co-generation), NOx emissions of less than 0.1g/km, a manufacturing cost of $400,450/kW, and a maintenance cost of less than $4,000,000/kW. USD/kW, maintenance costs below 0.01 USD/kwh, and high engine reliability while meeting these goals.

1.2 Alcohol cars

Alcohol cars is to methanol, ethanol and other alcohols as fuel for the car, the use of a wider range of ethanol, ethanol from a wide range of sources, the production technology is mature, the latest use of cellulosic raw materials for the production of ethanol technology and its use of raw materials almost all of the agricultural and forestry wastes, urban living organic waste and industrial organic waste. Alcohol cars at present more than the use of ethanol and gasoline or diesel fuel blended with any proportion of flexible fuel drive, both without the need to transform the engine, but also to play a good energy saving, pollution reduction effect, but this blended fuel to obtain the same power with gasoline or diesel fuel, you must increase the amount of fuel injection, when the blending rate of alcohol is greater than 15% -20%, the engine should be changed to the compression ratio and ignition advance Angle. Theoretical air-fuel ratio of ethanol fuel is low, the engine intake system requirements are not high, poor spontaneous combustion performance, high octane number, high explosive resistance, volatility is good, the mixture is uniformly distributed, high thermal efficiency, automobile exhaust pollution can be reduced by more than 30%. This kind of car was first developed by Ford in the mid-1980s, and by the end of 2003, there were more than 2.3 million ethanol cars in the U.S., most of which were Dodge and Chrysler vans - 233,466 had been sold in 2003.

1.3 Hydrogen Fueled Vehicles

Hydrogen is a clean fuel, and the use of hydrogen as a fuel requires only minor modifications to the conventional spark-plug ignition engine, which has a higher combustion efficiency than gasoline, and a mixture that can be thinner to a greater extent, requiring less ignition energy, which is conducive to fuel conservation. Hydrogen can also be added to other fuels (e.g., CNG) to improve efficiency and reduce N02 emissions. Hydrogen has one of the highest mass energy densities of all fuels, but the lowest volumetric energy density, and the biggest obstacles to its use are storage and safety issues. BMW has been committed to hydrogen engine development, developed a variety of hydrogen engine cars, its 7 series sedan equipped with a V12 hydrogen engine is the world's first mass-produced hydrogen engine, the engine can use hydrogen and gasoline two fuels.

1.4 DME cars

Dimethyl ether (DME) is a colorless and odorless gas with excellent combustion performance, clean, high cetane number, good power performance, less pollution, a little pressure is liquid, very suitable for compression-ignition engines as a substitute energy, the use of the fuel vehicles can reach the California ultra-low emission standards. Japan's NKK company has successfully developed equipment to produce dimethyl ether with poor quality coal, and Sumitomo Metal Industries completed a test in 1998 with dimethyl ether as a car fuel, dimethyl ether vehicle (DMEV) will not emit black gas pollution of the environment, NOX produced than diesel fuel 20% less.

1.5 Pneumatic car

To compressed air, liquid air, liquid nitrogen, etc. as a medium, through the heat absorption and expansion of the power supply drive energy of the car is called a pneumatic car, pneumatic engine does not burn or other chemical reactions, the emission of pollutant-free radiation of air or nitrogen, the real realization of zero pollution. At present, the development of more successful is compressed air-powered vehicles (APV), the working principle is similar to the traditional internal combustion engine car, but the energy to drive the piston connecting rod mechanism from the high-pressure air. the APV media source is convenient, clean, social infrastructure construction costs are not high, easier to build. No fuel combustion process, low requirements for engine materials, simple structure, can draw on existing internal combustion engine technology and thus short R & D cycle, design and manufacturing easy. However, the current APV energy density and energy conversion rate is not high enough, short range. 1991 French engineer Guy Negre obtained a patent for compressed air power engine, and joined the MDI company, in 2000 the MDI company launched the name of "evolution" (evolution) of the APV, the mass of only 700kg, its engine mass of only 700kg, the MDI company launched the APV, the MDI company launched the APV. The quality of only 700kg, its engine quality is only 35kg, speed up to 120km / h, a full of compressed air can be traveling 200km, inflatable cost of only 0.3 U.S. dollars, in the city can be driven about 10h, in the compressed air station inflatable 2min can be completed, with the air pump inflatable 3h can be completed.

1.6 Electric Vehicles

The world's first electric vehicle (EV) was manufactured by Americans in the 1890s.EVs are broadly categorized into battery-electric vehicles (BEVs), fuel-cell electric vehicles (FCEVs), and hybrid electric vehicles (HEVs). A ***identical feature of electric vehicles is that the vehicle is driven entirely or partially by electricity through an electric motor, enabling low and zero emissions.

Battery electric vehicles were the first electric vehicles to appear. The use of lead-acid batteries car vehicle dynamics, range and traditional internal combustion engine vehicles have a large gap, and the use of high-performance nickel-metal hydride batteries or lithium batteries will make the cost greatly increased. JtBEV requires a certain charging time and corresponding charging equipment, the use of which is limited. Fuel cells have nearly 65% energy utilization, can achieve zero emissions, low noise, the latest development of high-performance fuel cells have been able to achieve almost with the traditional internal combustion engine car equivalent power performance, the development prospects are very good, but the cost is the constraints on the industrialization of the bottleneck. Demonstration tests conducted in Canada showed that the use of fuel electric his public **** car manufacturing cost of 1.2 million Canadian dollars, while the use of diesel engine public **** car is only 275,000 Canadian dollars.

Hybrid vehicles integrate the advantages of traditional internal combustion engine vehicles and electric vehicles, while overcoming the shortcomings of both, and in recent years has gained rapid development, and has been industrialized and commercialized, the success of the PRIUS and INSIGHT two hybrid vehicles to show people the charm of the hybrid technology and huge market potential.

1.7 Vehicles fueled by vegetable oil

In order to find new energy sources that can replace petroleum, scientists are also focusing on vegetable oils, and are developing internal combustion engine oils based on vegetable oils such as soybean oil, corn oil and sunflower oil. Scientists are also researching biodiesel, a fuel made from vegetable oil, which can be used in large quantities in trucks and ships in the future as a substitute for diesel. Biodiesel does not contain sulfur, so it does not threaten the environment with acid rain. To produce biodiesel, chemists are esterifying vegetable oils to turn them into methyl ester compounds that burn cleaner and leave less residue in the engine.

2 Overview of the development of new energy vehicles in China

China's natural gas resources are abundant and widely distributed, Hainan, Beijing, Shanghai, Chongqing and other provinces and cities are listed as the national key demonstration cities for gas vehicles, everywhere in the fuel car based on the development of compressed natural gas vehicles and liquefied petroleum gas car modification, mainly used for cabs, buses and buses, large vehicles and engineering facilities, etc.. FAW-Volkswagen has developed Jetta LPG, Shanghai Jiaotong University has developed LPG cars and Shenwo Bus has jointly developed modified LPG city buses, and Beijing has developed CNG city buses.

Shanxi is a major coal-producing province, and the project of methanol vehicles has been carried out for many years, and has now reached the stage of commercial operation, and the methanol vehicles used are equipped with a flexible fuel system, which can be used for both methanol and liquefied petroleum gas (LPG). The methanol vehicles used use a flexible fuel system, which can use both methanol and gasoline, and use ethanol as an aerobic fuel, and are now being promoted in Hebei and Heilongjiang. At the same time, the country has formulated standards related to ethanol gasoline fuel. China's Yungang Automobile Company Datong Automobile Manufacturing Plant has developed methanol medium buses.

China is rich in coal resources, and the government supports the project of making motor fuel from coal. Coal direct liquefaction and indirect liquefaction of automotive fuel projects are actively underway. "During the Tenth Five-Year Plan, coal direct liquefaction demonstration plants were set up in Yunnan and Shaanxi to synthesize automotive fuels such as petroleum or dimethyl ether from coal. Xi'an Jiaotong University and the Institute of Coal Chemistry of the Chinese Academy of Sciences developed an "ultra-low-emission dimethyl ether vehicle" in 2000 after five years of collaborative research, and through the test of burning dimethyl ether in the TYll00 single-cylinder diesel engine and the van equipped with the CA498 diesel engine produced by Dalian Diesel Engine Plant, it was found that the engine power could be increased by 10-15%, and the engine power could be increased by 10-15%, and the engine power could be increased by 10-15%. Can be increased by 10% -15%, thermal efficiency increased by 2-3 percentage points, noise reduction of 10% -15%.

China's fuel cell research units engaged in more than 20, proton exchange membrane (PEM) fuel cell technology has made greater progress, but there is still a small gap with foreign countries, for example, foreign countries will be the power of 50-80kW of the PEM fuel cell used in cars, while China's largest single stack of PEM fuel cell power of 5kW, far away from the use of cars. It is far away from the use in cars. China's metal fuel cell technology has reached the world's advanced level.

China's nickel-metal hydride batteries and lithium batteries have also reached the international advanced level, BYD's E1 electric car displayed at the 2005 Shanghai Auto Show has a very good car power performance.

Currently the most reported domestic research on compressed air-powered vehicles is Zhejiang University, they have developed a compressed air-powered motorcycle research platform, explored a number of useful conclusions, is further in-depth research, in addition to Chongqing University and Tongji University have done some exploratory research. It should be said that the development of APV in China has just begun.

3 Alternative Fuel Vehicle Development Prospects

In a variety of automotive alternative fuels, LPG and CNG are the most convenient to put into use, and now has a good supporting infrastructure. In the emission and economic performance requirements and power performance requirements of the general public **** transportation field has a very good application prospects, the United States in recent years the new buses in the natural gas vehicles accounted for a large proportion. In such a large agricultural country as China, especially in some large agricultural provinces, ethanol resources are abundant, ethanol vehicles have good prospects for application. DME and other synthetic fuels have good emission characteristics, will also have good application prospects, especially as a substitute for diesel used in hybrid vehicles. Hybrid vehicles are undoubtedly the main form of next-generation automotive powertrains.

Battery electric vehicles are not as usable as hybrid and fuel cell vehicles and are costly. The energy utilization of hydrogen fuel engines is not as good as that of hydroxide fuel cells. Thus, the development prospects of battery electric vehicles and hydrogen engine vehicles are not very optimistic. Of course, with the development of solar cell technology and breakthroughs, perhaps pure electric vehicles can usher in a good development situation. Although compressed air-powered vehicles have realized zero pollution, their overall performance is too far from that of traditional cars, and they can only be used in a smaller range for specific applications.

Fuel cell is the highest energy utilization of automotive energy under the current technical conditions. The specific energy of fuel cell can reach 200-350Wh/kg, which is 2-3 times of lithium-ion battery; the energy conversion efficiency is as high as 60% to 80%, which is 1.5 to 2 times of gasoline or diesel engine, and it can realize ultra-low pollution or even zero pollution, and the hydrogen energy used in fuel cell is renewable. At present, methanol fuel cell technology is the most mature. Major foreign oil companies and automobiles are committed to the research and development of fuel cell vehicles to seize the beachhead in the future development of automobiles. Daimler-Benz has launched NecarI-NecarⅣ and Nebas series of FCEV from 1993 to 2000, and Necar4 was tested in the U.S.A. in May, 2001, with a power of 55kW, a maximum speed of 145km/h, and a loading trip of 450km. The latest Necar V-FCEV using methanol fuel cells. 1997 Ballard Power Company and Ford Motor Company formed the Xcellsis company to develop fuel cell cars, the United States AR-CO, Shell, Texaco and other oil companies and California CARB has joined the formation of the world's strongest alliance for the development of fuel cell vehicles. Japan's Central Research Institute of Electric Power is developing a comprehensive use of heat-resistant ceramic fuel cells, batteries in the power generation efficiency is very high at a high temperature of 1,000 ℃ work, the electrolyte output power to 1W/cm2, equivalent to 5 times the traditional fuel cells. EvomR is committed to the development of aluminum and zinc fuel cells, has been a considerable level.

In short, the comprehensive evaluation of alternative fuels should take into account the following factors: fuel cost; vehicle cost; dependence on imported oil; effective energy utilization; greenhouse effect; emission pollution; production, storage, distribution, refueling facilities; loaded mileage and refueling time; safety. Based on these factors, the most readily available alternative fuels are CNG and LPG. electricity, methanol, and ethanol all have lower overall evaluation indices than gasoline. It can be expected that the market share of LPG and CNG as well as ethanol will continue to grow. DME and synthetic diesel will see their market share grow rapidly and steadily after ten years. Hybrid vehicles will further develop and rapidly increase their market share. Fuel cell vehicles will gradually increase their market share after 20 years of industrialization. The market share of traditional gasoline-powered vehicles will begin to decline significantly after 20 years, but diesel vehicles will continue to maintain a high market share in the field of heavy-duty vehicles.

4 Conclusion

In the next 20 years, gasoline and diesel will continue to be the main sources of energy for automobiles, but the quality of gasoline and diesel is becoming more and more demanding, and engine technology will evolve rapidly to improve energy efficiency. Alternative fuels will be rapidly utilized, with natural gas and ethanol vehicles being the first to be put into use on a large scale, and dimethyl ether and synthetic fuels gradually expanding their use.

Hybrid systems will be rapidly developed and applied, and hybrid vehicles will be the most practical way to solve the energy and pollution problems of the automobile industry for at least 30 years. Therefore, resources should be integrated to accelerate the development of hybrid vehicles to seize the new high ground of automotive technology development.

Fuel cell is the most promising automotive energy, but also the main energy source of the future car, the domestic oil industry should join hands with the automotive industry to develop advanced fuel cell technology, to seize the forefront of the future advanced automotive technology!