Mentioning levitation, we will immediately there is a feeling on the tall, technically inevitable that the maglev is the latest, the speed must be the fastest. After all, the flight train is suspended on a track, it's hard to feel no science fiction.
Vacuum maglev train on tall
It proposed the concept of magnetic levitation vacuum, and further reinforced the feeling, China Southwest Jiaotong University and Johns Hopkins University, have proposed vacuum maglev program.
Typically, the civil aircraft in air cruising speed of about 850 km / h for more than 8000 km or more traveling, take the time and economic costs of the aircraft cost is staggering, and because of the large number of serious environmental pollution emissions. Is there a faster tool to allow people to travel faster, more economical and more environmentally friendly travel it?
Thus, the vacuum magnetic levitation is presented as a choice people. The so-called vacuum magnetic levitation, is in a vacuum inside the pipe laying maglev line, and then let the train operators in the vacuum line. Because there is no air resistance, vacuum maglev speed of up to 3000-4000 km, one of the airliner's not very energy, and noise emissions close to zero.
Yaoping China Southwest Jiaotong University chaired the "High Speed Maglev Transportation Evacuated Tube Basic Research Project No. 50678152)," 2007 was supported by the National Natural Science Fund Project. Currently Yaoping been transferred to Xijing Institute of Shaanxi Province, set up a special vacuum Road Transport Institute, is to promote the "transport revolution" into the reality.
However, as of now, after all, still in the vacuum maglev concept stage, taking into account the huge construction costs and maintenance issues, as well as the practical application of the vacuum magnetic levitation from a very far distance.
Not only is the vacuum magnetic levitation, is an ordinary normal conducting magnetic levitation superconducting maglev technology in the world is very few. One technique is so tall, why does not the global popularity? Chinese high-speed rail construction Why not use magnetic levitation technology?
Rough road Maglev technology worldwide promotion
And in our hearts, "tall" is different, unveiled maglev you will find the following facts: First, the magnetic levitation is actually not a new technology. 1922 originated in Germany in 1934, the country engineer Hermann Kemper applied for patent maglev train. Second, it does not necessarily mean high-speed magnetic levitation. 1984, a commercial magnetic levitation train in Birmingham International Airport put into operation, a total length of 600 meters, 42 kilometers per hour operations, 11 years after the issue closed for maintenance.
The basic principle is to use magnetic levitation "same-sex repulsion, opposites attract," the electromagnetic theory, allow the vehicle to levitate using electromagnetic force to guide and promote the former train line. Currently maglev train technology in the world there are two main schools:
First, Germany is represented by the normal conducting magnetic levitation. Track is a T-type units, on both sides of the lower part of both sides of the train tracks take the T-wrap by conventional electromagnets mounted at the bottom of the train body and suspension to achieve attractive electromagnet located above the magnetic tracks between. Advantages of normal conducting magnetic levitation technology is simple, disadvantage is the electromagnetic attraction generated is small, the gap between the train and the track is about 8-10 mm. Normal conducting high-speed maglev train speeds up to 400 km -500 km.
Shanghai Pudong Airport line is used in the German maglev technology often lead by the German Transrapid company in 2001 in China Shanghai Pudong International Airport to Longyang Road subway station construction in 2002, was officially opened. The line length of 30 kilometers, the maximum train speed of 430 km, the average running speed of 380 km radius of the corner of 8000 meters from the starting point to the terminal only 8 minutes.
Second, Japan is represented by a superconducting maglev system. Superconducting magnetic levitation train is not track the package, but the package train track, it is the use of superconducting magnets in the vehicle during the movement and the induced magnetic field generated mutual repulsion track suspended over the track, the train operators in a U-shaped groove . Superconducting magnetic levitation, suspension air gap is large, generally about 100mm. Advantages of superconducting magnetic levitation force is suspended, the train runs fast, can run more than 500 kilometers per the disadvantage is the technical complexity, need to shield divergent electromagnetic field.
Maglev technology is quite advanced. Because unlike traditional wheel-rail train while the train without touching the track, so only by resistance from the air, it is easier to achieve high-speed operation, in theory, you can follow the 500 km per hour operations. But the reality is that high-speed magnetic levitation technology, in the promotion of the way the world is unusually rough.
First we look at the case of magnetic levitation to promote the birthplace of Germany. Germany is still not a single commercial operation of the Maglev line, even in the German media sector, the magnetic levitation train technology called "expensive high-tech toys." After 1989 in Berlin, Germany 1.6 km length of the construction of the driverless train, and passenger test operation, in July 1991 the official service, the Berlin Wall was abandoned drained.
Since then made three consecutive German maglev route planning, but they have out, no one can succeed. In 2000 the German capital Berlin to the proposed maglev line industrial cities of Hamburg, Germany in 2003 proposed the Ruhr area city express maglev project, but not all approved by the relevant departments. In 2008, Germany again raised the Munich airport maglev project, but the third out. In 2006, September 22, Germany Lathen - drpen maglev test line also occurred derailment accident, resulting in 25 people killed and four others seriously injured. The incident reflects the maglev train in case of sudden braking capability inferior to the wheel-rail trains. This further affects the magnetic levitation train technology promotion in Germany.
Secondly, we look at magnetic levitation technology is another big country of Japan. Japan's maglev technology began in 1962, in December 1979 test speeds of up to 517 kilometers, in November 1982, manned maglev train test was successful. In 1997 a total length of 18.4 km of Japan Yamanashi Maglev Test Line and began building a successful test run, in 2003, Japan 3 grouping MLX01 maglev 581 km create a world record.
But the construction of high-speed maglev line in Japan but still difficult. The early 1990s, the Japanese planned Tokyo - Osaka maglev line, and a feasibility study, but eventually shelved because of the high price tag.
But Japan's ambition to promote the maglev has not obliterate. 20 years later, in August 2013, Japan started again to connect Tokyo to Nagoya in central Shinkansen project, and strive to open in and vowed to build a maglev line between Tokyo and Osaka in 2045. Japan also tried to promote its own maglev technology in other countries in the world in 2014, the Japanese government announced that the United States free transfer of magnetic levitation technology, they aimed at the Washington - Baltimore high-speed rail line, the project will reportedly cost one trillion yen.
Bright future, but the road is not flat.
Why not choose China High Speed Rail Maglev?
Maglev high-speed rail line used to be an option for China, and is an important option.
The story takes place in China's high-speed rail Beijing-Shanghai high-speed rail line benchmark.
In 1990 the former Ministry of Railways to complete "the Beijing-Shanghai high-speed railway line project ideas Report," an official at the State Department in 1993 project project, 1997 on the Beijing-Shanghai high-speed rail financing, cost recovery methods demonstrated initially completed, everything is in place, only a strong wind.
About this time in the end is the use of the wheel-rail or the use of magnetic levitation controversy surfaced.
In 1998, the Chinese Academy of Sciences Zuoxiu, academician Xu and Yan Luguang three Beijing-Shanghai high-speed railway construction should be 500 km per hour maglev line. The main reason is that, up to 1300 km Beijing-Shanghai high-speed rail, high-speed rail over a reasonable range of 800 km, the train running time up to 5 hours, civil aviation passenger unattractive.
Wheel-rail faction also presented evidence to refute tit for tat.
Debate for 10 years. In 2008 the Beijing-Shanghai high-speed railway officially started, the wheel-rail faction wins.
As more advanced technology, higher operating speed magnetic levitation technology, why would finally defeat? There were two reasons.
First, the comparative advantages of maglev noticeable. Maglev rail relative wheel, the biggest advantage is speed. But when the wheel speed rail test has exceeded 574.8 km, operators can break the speed of 350 km when the speed magnetic levitation is not so obvious. If the Beijing-Shanghai high-speed rail operators to achieve 350 kilometers per hour, travel time between Beijing and Shanghai will be compressed to 3.5 hours, even if the operating speed of 300 km, travel time and now has less than five hours.
Maglev is not to overcome the friction between the wheels and the track it? Ordinarily it should be obvious speed advantage? why? In fact, this is a high school physics problem, air resistance high-speed operation of the object is quadratic speed, the energy consumption is the cube of the speed, when the speed of 300 km or more, the drag on the moving object 90% of air resistance, maglev Although no mechanical resistance, air resistance but does not eliminate, but also the need to train a magnetic float, but also consume large amounts of energy. So when the wheel-rail technology easily exceeded 300 kilometers per hour, even up to 350 km, the relative advantages of maglev technology is not so obvious.
Second, some of the more obvious maglev technology disadvantages difficult to overcome. Such as economic factors, the construction cost of the maglev line to be substantially higher than the wheel-rail line construction. Shanghai maglev line length of 30 kilometers of lines, the design of investment reached 10 billion yuan, while Germany's two lines, a 36.8 km, is expected to cost about 1.6 billion euros (13.28 billion yuan); another length of 78.9 km, is expected to cost 32 billion euros (26.56 billion yuan).
In addition to technical reasons. High-speed rail to play its biggest utility, must be networked. A relative of a solitary line, high-speed rail network performance will exponentially grow exponentially. However, the magnetic levitation technology is inherently ad hoc transport and health, because both the normal conducting or superconducting Maglev magnetic levitation technology shortcomings are difficult to orbit, it is difficult to maglev network. Normal conducting magnetic levitation technology, is holding rail train, so the technology is very difficult and superconducting magnetic levitation is running on a U-shaped groove orbit harder.
Orbit difficulties will bring additional difficulty that rescue. China Shanghai Pudong Airport maglev train line, there had been a fire accident, a week after the accident the train was towed away. It is also a Vital maglev train.
The rise of low-speed maglev
High-speed maglev in the promotion of global exception bumpy road, the only route to run a commercial maglev line in Shanghai Pudong, has also been a substantial loss in the state. However, the low-speed maglev line is another way, a great prairie fire-related promotion.
Japan is the first country, the country's development maglev line more pragmatic, on the one hand to strengthen the high-speed maglev technical reserves, and is poised to promote the implementation, on the other hand, the first to build low-speed maglev line operators. Japan's first maglev railway official carrier is leading to downtown Nagoya Aichi Expo venue maglev line, the railway in March 6, 2005 the official opening, nine-kilometer, half-way with nine stations. The maglev train constituted by the three cars, the whole unmanned, a top speed of 100 km, with the entire process takes 17 minutes.
South Korea is the second country. In recent years, South Korean rail technology has developed rapidly in the global market and the fierce competition of Chinese enterprises. Low-speed maglev technology is a focus on the development of rail transportation in Korea. Korean maglev development of experienced independent research (1985 - 1993), foreign cooperation (1994 - 1998) and commercialization attempts (1999-present) three stages.
In December 2006, South Korea announced investment in research and development of unmanned low-speed maglev train for the next generation of city traffic. July 2014, Incheon International Airport to Incheon Longyou maglev line put into operation, a total length of 6.1 kilometers. Independently developed by the South Korean train, unmanned, a top speed of 110 km. Korea after Japan became the second country with low-speed maglev lines.
China is a country in the world has a low-speed maglev technology. After 2000, China's low-speed maglev promotion have a variety of rumors, including Beijing Badaling line, Chengdu Qingcheng Mountain project, Dongzhimen to Beijing Capital Airport, Shanghai-Hangzhou maglev lines, but nothing came.
But after 2008, China's low-speed maglev development and promotion into the acceleration phase.
In May 2008, passenger car plant in Tangshan built a 1.547 km of medium and low speed maglev train engineering test model line. In 2009 Tang car company developed low-speed maglev train line.
2011 China South Locomotive and signed Changsha in Changsha, Zhangjiajie government signed a "low-speed maglev project Zhangjiajie letter of intent", plans to build China Zhangjiajie low-speed maglev line's first commercial operation.
January 2012, China CSR Zhuzhou company developed low-speed maglev train off the assembly line, a top speed of 100 km, maximum capacity 600 people.
May 16, 2014, Changsha high-speed rail station to Huanghua International Airport maglev project officially started construction, is expected to completed by the end of 2015, which is China's first completely self-developed commercial operation Maglev line.
Meanwhile, the low-speed maglev line in Beijing S1 line is rapidly advancing.
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China after the rapid development of high iron wheel rail technology, is the field of magnetic levitation quietly implement a new round of counter-attack.
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