Maglev train is a modern high-tech rail vehicle, which realizes non-contact suspension and guidance between the train and the rail through electromagnetic force, and then draws the train by electromagnetic force generated by linear motor.
Origin of magnetic levitation:
In p>1922, German engineer Hermann Compel put forward the principle of electromagnetic levitation, and then applied for a patent. Since the 197s, with the economic strength of industrialized countries increasing, Germany, Japan, the United States and other countries have successively carried out research and development of magnetic levitation transportation systems in order to improve their transportation capacity to meet the needs of their economic development and people's livelihood. Among them, Germany and Japan have made remarkable achievements.
China's first maglev train (bought from Germany) started running in Shanghai in January 23. 215-1 Changsha Maglev Line, the first domestic maglev line in China, was successfully put into trial operation.
Types of magnetic levitation:
There are three types of magnetic levitation in the world at present. One is the normally conductive magnetic levitation represented by Germany, and the other is the superconducting electric magnetic levitation represented by Japan. Both kinds of magnetic levitation need electricity to generate magnetic levitation power. The third type is the permanent magnet suspension in China, which uses special permanent magnet materials and does not need any other power support.
why can't magnetic levitation be widely used at present? Why didn't China high-speed rail choose maglev? We should start from the following three aspects.
1. Technical conditions need to be overcome
Up to now, it can be said that the maglev train track technology is in China, and the maglev train technology is still in Germany, so it is impossible to introduce technology from imported products. China's wheel-rail railway technology has a history of nearly a hundred years, forming an industrial army specializing in locomotive design, scientific research and innovation, and has an industrial chain of more than 4, people who have been designing, manufacturing, operating and maintaining for decades. Magnetic levitation technology is in the hands of a few experts and professors, and it does not have the application conditions. The maglev train needs to be elevated, and the winding of the elevated beam must be less than 1 mm. Therefore, the span of the viaduct is generally less than 25 meters, and the pier foundation is more than 3 meters deep. Therefore, a retaining wall of more than 2 kilometers should be formed on the ground from Shanghai to Hangzhou. In addition, due to the influence of operation dynamics, no other buildings are allowed within 1 meters on both sides of the track. The construction of Shanghai-Hangzhou maglev occupies a large area and has a great impact on the environment.
2. Uncontrollable factors (hazards) occur in an emergency
In p>26, a German maglev control train collided with a maintenance vehicle during its trial operation. It was reported that there were 29 people on board, 23 people died on the spot, 25 people actually died and 4 people were seriously injured. This shows that the braking ability of maglev train is not reliable under sudden circumstances, which is not as good as that of wheel-rail train. ?
it is dangerous for vehicles on land to have no wheels. Because the train has to drop from a great momentum to a standstill, and to overcome a great inertia, it can only be overcome by the braking force of wheels and tracks. The maglev train has no wheels. If there is a sudden power failure, it is very dangerous to rely on sliding friction. In addition, the maglev train is elevated, so it is difficult to rescue at a height of 5 meters when an accident occurs. Without wheels, it is difficult to drag it out of the accident site. If there is a power outage in the interval, it is difficult for other vehicles and cranes to get close.
3. The investment is huge, and the profit is difficult
Even if there are means to solve the above technical problems, it involves another problem-money. The design investment of Shanghai Pudong maglev line about 3 kilometers is 38 billion yuan, and it has been in a state of substantial loss; The two lines in Germany, one of which is 36.8 kilometers long, will cost about 1.6 billion euros; The other 78.9 kilometers long will cost 3.2 billion euros (1 euro is about equal to 1 yuan RMB). In actual construction, according to the difference of topography, pavement and designed transportation capacity, the cost will of course vary greatly. But in any case, a one-kilometer route needs at least 3 million yuan of investment, that is to say, a 1 cm line will cost 3, yuan!
Finally, a comparison chart of the differences among high-speed trains (commonly known as high-speed trains), bullet trains, general-speed trains, intercity trains and maglev trains summed up by individuals is concluded. (The functional attribute is different from the product attribute)
I am a psychology enthusiast who is engaged in high-speed rail advertising
-Qikai I love psychology, learn some psychology, be happy, welcome to pay attention to my original article
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