From February 2 to 4, the Beijing Winter Olympic Torch Relay will be held in Beijing, Yanqing and Zhangjiakou, and about 1,200 torchbearers will participate in the relay. Named "Flying", the Winter Olympic torch is shaped like a ribbon flying and fluttering, and the shell color is silver and red gradient.
What black technology does the torch "fly" hide? Recently, Nandu reporter approached the R&D and production team of Sinopec Shanghai Petrochemical, which undertakes the task of R&D and production of the Winter Olympic torch, and unveiled the mystery of the mass production of the torch.
The research and development team told Nandu reporter that the "flying" torch is a carbon fiber hydrogen energy torch, weighing about 1.5 kg. Compared with the previous Winter Olympic torches, the materials and fuels of the "Flying" torches use the hottest scientific and technological elements at present, which fully reflects the concept of scientific and technological Winter Olympics and green Olympics.
Beijing Winter Olympic Torch. Xinhua News Agency
New material: The use of carbon fiber to make a torch shell is the first time in the world
If the shell of the Winter Olympic torch is compared to "reinforced concrete", carbon fiber is "steel" and resin is "concrete".
Carbon fibers are fibers about 5-10 microns in diameter and are mainly composed of carbon atoms. What are the advantages of carbon fiber? Its relative density is less than 1/4 of steel, but its tensile strength is 7-9 times that of steel, with high stiffness, high tensile strength, low weight, high chemical resistance, high temperature resistance and low thermal expansion, which make it very popular in aerospace, rail transportation and motorsport. It is understood that in addition to China, at present, only a few developed countries such as Japan and the United States in the world have mastered carbon fiber technology, which is also the first time in the world that carbon fiber materials are used for the production of Olympic torch shells.
At the Sinopec Shanghai Petrochemical Carbon Fiber Plant site, after several processes, the carbon fiber is packaged and transported to the Yunlu Composites Company in Huai'an, Jiangsu Province, where a three-dimensional weaving machine specially developed for the Winter Olympic torch weaves the carbon fiber into the shape of a torch shell like a knitted sweater, and then sent to the Shanghai Core Eight Institute to put the mold into the mold to solidify the molding.
"In the past, the Olympic torch was generally made of metal materials", Huang Xiangyu, deputy general manager of Shanghai Petrochemical and deputy head of the torch mass production project leading group, introduced that the torch of the recently concluded Tokyo Olympic Games was mainly made of aluminum, compared with the same volume of aluminum alloy, carbon fiber composite material weight is about 30% lighter. In addition, carbon fiber composite materials are not easy to thermal expansion and contraction, good dimensional stability, better than metal materials, conducive to post-assembly.
Huang Xiangyu said that due to the low temperature when the Winter Olympic torch is passed outdoors, compared with metal materials, carbon fiber composite materials will not be cold and sticky, and the touch is better.
Huang Xiangyu was interviewed by CCTV to introduce the material of the Winter Olympic torch. Screenshot of CCTV
New Energy: Hydrogen Fuel for "Zero Emissions"
The torch fuel for the 2008 Beijing Olympics was propane, and 13 years later, the torch fuel for the 2022 Beijing Winter Olympics used the hottest new energy source of the moment, hydrogen. Nandu reporter learned from the R & D team that hydrogen is taken from water, and after combustion, it becomes water, which can achieve zero carbon emissions.
Although hydrogen is green and environmentally friendly, storing enough hydrogen in a hand torch is not an easy task.
"Hydrogen cylinders can be made by everyone, but it is difficult to make such a small hydrogen cylinder for a long time." Huang Xiangyu introduced that the hydrogen density is very low, due to the small size of the handheld torch, the volume of the hydrogen cylinder is limited, in order to store enough hydrogen, the research and development team uses a high pressure of 42MPa to compress 12 grams of hydrogen into the hydrogen cylinder, and then put the hydrogen cylinder into the torch.
After solving the problem of hydrogen storage, how to achieve safe decompression and stable supply of hydrogen is another problem facing the R&D team.
Huang Xiangyu introduced that after the completion of inflation, the internal pressure of the hydrogen cylinder is equivalent to 420 atmospheres, and the high-pressure hydrogen needs to be quickly converted to the standard atmospheric pressure when it is used, if the high-pressure hydrogen pressure is too strong, it is very easy to explode and other accidents, so the hydrogen cylinder must have a high safety. In this regard, the aerospace science and technology team has developed a high-precision pressure reducing valve, which can safely reduce pressure and stabilize the supply of hydrogen when it is used. In addition, the R&D team wrapped a layer of carbon fiber on the aluminum alloy liner of the hydrogen cylinder to make the hydrogen cylinder stronger and safer.
The use of hydrogen as a flare fuel also needs to solve the problem of flame color rendering. The flame when the hydrogen is burning is not obvious in daylight, and the R&D team also "dyed" the flame for this purpose.
"The flame is pale blue when normal hydrogen is burned and is nearly transparent in daylight. In order to enable the audience to see the flame clearly and let the flame have a higher color rendering, we coated the torch with sodium salt with color rendering function, and the flame color reaction will occur when the sodium salt is burned by the flame, so that the flame becomes a bright and bright golden yellow. Huang Xiangyu said.
Nandu trainee reporter Ding Jingxuan intern Zhao Ji sent from Beijing