Globally, compressed natural gas (CNG) and liquefied petroleum gas (LPG) have been used as automobile fuels for more than 70 years. The earliest CNG filling station was built by the Italians in 193 1, and then many countries in the world began to explore the technology of gas vehicles. Foreign countries have used CNG and LPG as automobile fuels for a long time. 1973 After the first oil crisis, all countries paid enough attention to it.
Since 1980s, with people's increasing attention to environmental pollution, CNG and LPG, as "clean fuels", have been strongly advocated in the world, and they have made great achievements in technology. Countries and regions with better development of CNG and LPG vehicles include the United States, Canada, Italy, the Netherlands, Australia, New Zealand, South Korea, Japan and CIS countries. The total number of CNG and LPG vehicles has reached 10 million, and reached more than 20 million in 2000. In order to adapt to the general trend of automobile energy reform, automobile manufacturers all over the world have invested in the development of natural gas vehicles. Such as American GM, Ford and Chrysler. Since 1994, German BMW Company has put into production with an annual output of 2,000 natural gas vehicles. The three major automobile companies formed a "natural gas automobile technology consortium", 1998 the cost of natural gas automobiles was halved. In Italy, the United States, the Netherlands, Australia, France, Japan, Singapore, New Zealand, Indonesia and other countries, more than 5 million natural gas vehicles have been driven, of which nearly 4 million are liquefied petroleum gas vehicles. It is reported that the annual growth rate of this kind of car in the United States is 13.46%. The main force to promote the application of natural gas vehicles is that governments all over the world regard the application and promotion of natural gas and liquefied petroleum gas vehicles as strategic energy measures, make them national policies, and enforce them by formulating laws and regulations. At the same time, various preferential and subsidy measures have been formulated to encourage them. With the support of policies, regulations and preferential measures, many countries have formulated development plans. For example, in the United States, at the beginning of the 20th century, 20 million cars used natural gas and liquefied petroleum gas. Russia plans to convert 18% cars and 40% buses into natural gas by 2005. The symbol of the development of gas vehicles in China is that 1988 established the first gas filling station in Nanchong, Sichuan. China has built more than 730 gas stations and transformed nearly 300,000 cars. Since 1995, China has been promoted by government actions, and its driving force has been strengthened year by year, which is a great encouragement to enterprises engaged in the R&D and manufacturing of natural gas and liquefied petroleum gas vehicles for many years. Many people of insight have also been put into the ranks of application promotion, and major cities are deploying and taking action. It can be seen from various newspaper reports that it is practical and feasible to replace oil with gas.
In the development of natural gas vehicles in China, all government departments work together to ensure the continuity and consistency of policies. In order to alleviate the contradiction between the increasingly serious environmental pollution and the rapidly developing automobile industry,1991February 7, 1999, the Ministry of Science and Technology and the former State Environmental Protection Administration jointly issued "Several Opinions on Implementing" Air Chemical Clean Automobile Action ",which decided that the car ownership accounted for 10% and the total mileage accounted for 40%-50%.
CNG vehicles are widely used in China, which can be fueled with compressed natural gas or gasoline respectively. In the future, CNG vehicles will be widely used, which is more environmentally friendly, energy-saving and economical than traditional petroleum. There are nearly 3,000 CNG vehicles in China, and 3 1 filling stations have been built. The development of LPG vehicles in China was after 1990s. Because it is easier to store and transport than CNG, it has a better development momentum and has surpassed the development of CNG vehicles. Judging from the trend of China, LPG vehicles will develop greatly in a short time. In 2000, taxi fleets and buses accounted for a certain proportion in some big cities, and will be vigorously promoted by 20 10. It is estimated that the total number of LPG vehicles in China will reach several hundred thousand. The popularization of CNG vehicles will lag behind that of LPG vehicles, but it will gradually develop in some cities and regions with obvious resource advantages. By 20 10, CNG and LPG vehicles in China will account for 2%~3% of the car ownership, of which 80% will be cars and passenger cars driving in cities.
From the "Clean Vehicle Action" to the major projects of energy-saving and new energy vehicles in the "Eleventh Five-Year Plan", the national science and technology plan has invested nearly 250 million special funds to support the technical research and demonstration evaluation of alternative fuel vehicles represented by natural gas vehicles, which has promoted the relevant scientific research investment, accelerated the concentration of scientific and technological resources and achieved a major breakthrough in the key technologies of natural gas vehicles. The scientific and technological support based on independent innovation provides a powerful impetus for the sustainable development of natural gas vehicles in China.
First, we have organized and implemented a number of independent innovation projects in Industry-University-Research for the powertrain and complete vehicles of alternative fuel vehicles, such as the development of single-fuel CNG vehicles, heavy-duty LNG commercial vehicles, CNG engines for heavy-duty trucks, in-cylinder direct injection LNG engines and dimethyl ether engines that meet the national standards. The design and development process has become increasingly standardized, and breakthroughs have been made in key technologies. The development of natural gas engines has changed from simple fuel substitution to positive development technology, and a number of key technologies such as supercharged intercooling and lean combustion have been mastered, and the technical level of natural gas engines has been comprehensively improved. Second, we organized and implemented a number of independent innovation projects on key parts and filling infrastructure of alternative fuel vehicles, such as "research and development and industrialization of special equipment for LNG/LCNG automobile filling stations", "research and development of mobile LNG skid-mounted filling stations", "research and development of detection technology and system for CNG gas storage wells" and "research and development of key technologies for special equipment for alternative fuel vehicles". We have mastered the development and manufacturing technology of various key components such as natural gas and liquefied petroleum gas cylinders, engine ECU, nozzles, high-precision pressure reducer and other major equipment such as large-displacement natural gas main station compressor, and the product performance is close to the international advanced level. Third, we organized and implemented a number of capacity-building scientific and technological projects, such as "gas vehicle power system technology platform and vehicle development", "biodiesel component and vehicle matching technology research and development", "vehicle biodiesel testing and evaluation technology research and development", "hydrogen and natural gas engine development" and "methanol flexible fuel vehicle development". A group of R&D teams with vehicle and engine backbone enterprises as the core and active cooperation between scientific research institutes and universities have formed a strong product development capability and have begun to undertake it.