The Winter Olympics in Beijing have opened in a grand ceremony at the National Stadium, known as the Bird's Nest. When the last torch was placed on the main platform, the dream came true in the collision of ice and fire.

Space technology has lit the cauldron of the Winter Olympics

      In the design and development of the torch, aerospace technology has made a great contribution to the continuous burning of the Olympic flame flashing the glory of "green Winter Olympics" and "scientific Winter Olympics". The torch has a green and energy-saving "heart". Hydrogen, as the fuel for the torch, is green, environmentally friendly and pollution-free, but there are a series of problems such as inflammable and explosive, easy to leak and difficult to control. As a result, there is no precedent for a successful use of hydrogen as fuel for the torch at the 2022 Winter Olympics.

It is reported that hydrogen energy in the space field has been a great display. Liquid hydrogen has been widely used in the development of rocket engines in China. For example, it provides reliable power guarantee for long March 3A, Long March 5, Long March 5B and Long March 7A series of carrier rockets to go to space.

But using hydrogen as torch fuel isn't easy: First, how do you keep the flame alive in the cold outdoor environment of the northern winter? Like space missions, the Olympic torch has high reliability requirements. Secondly, how to ensure that hydrogen does not leak during transportation and transfer? The flame of the torch can not be like a rocket engine jet out, how to have a curve beauty and so on......

From the "crossover" of the space engine to the Olympic torch, 11 institutes (Beijing) of the Sixth Academy of China Aerospace Science and Technology Group and 101 institutes of the Sixth Academy of China Aerospace Science and Technology Group formed the torch development team. After about two years of technical research, the torch has solved many problems, such as the visibility of hydrogen flame, the adaptability of complex curved surfaces, large proportion of decompression, safe utilization of hydrogen, hydrogen fuel storage and so on. "In the process of design and development, we have collected information about the Olympic Torch for nearly a century and learned from the successful experience of other countries. The torch fuel has evolved from magnesium to propane to pollution-free and zero-carbon hydrogen. This reflects the green concept of the Beijing Winter Olympics and China's scientific and technological strength. It will also help promote hydrogen technology in China." Development team said about the person in charge.

For the first time in the history of the Winter Olympics, the torch has zero carbon emissions

　　The way in which the cauldron will be lit is always a favorite of the Opening ceremony of the Olympic Games. The final torchbearer of the Winter Olympics inserted the torch directly into the cauldron, creating a seamless flame connection without igniting the flame. Compared with the previous burning torch, about 99.9% of the energy can be saved, the concept of low carbon environmental protection.

"High appearance level" torch should have sufficient technical support

　　The crystal clear main torch, and the previous main torch in the visual effect is also very different. The development team adopted the creative form of "micro fire + display screen", and completed the 360 degree rotation of the main torch at a height of 40 meters with the smooth cooperation between the actuator suspended on the WIYA and the ground device, realizing the perfect integration of "fire" and "stage beauty".

From the shape, the main torch is composed of small snowflakes and olive branches. The color and brightness of each light point can be controlled independently. The 4.8mm light point realizes the delicate and colorful changes of the light pattern.

The "high appearance level" of the main torch requires excellent technical support. In order to show the lightness of the torch and achieve the stability of the overall structure, the development team had to "calculate every ounce" in the design, and chose aluminum alloy as the material, which only weighs about 1/3 of steel, to achieve the lightweight requirements. At the same time, in order to achieve efficient and stable combustion during rotation, the main torch adopts the combustion technology of space hydrogen and oxygen engine. Under the support of the high-end technology of the space power, the main torch does not flameout, do not temper, do not deflame, quite reliable.

Above the main torch, there is a rectangular black box called the Attitude Adjustment Actuator. It is hung in the wiya trolley, by the trolley with it moved to the central position, put down the wire rope and cable connected with the main torch, through the advanced attitude control technology, with the ground device to complete a series of actions.

Also hidden in the attitude control actuator are hydrogen slip rings for the fuel supply system, flexible hoses and a skid-mounted hydrogen system. The flexible hose, known as the "life tube" for the main flame, delivers hydrogen from the cylinder to the center of the flame to support the flame's combustion. Slip ring is to realize the continuous and stable supply of hydrogen in the state of motion; The skid-mounted hydrogen system is an integrated system consisting of a gas tank, a two-way decompression system and a solenoid valve. The main function is to achieve a stable supply of gas.

Safe and reliable in order to make sure that the main torch burning, developed team also give full play to the space engineering research and development management experience, to carry out the fault mode, effect and harm analysis, through the whole process, a comprehensive test to solve the flexible environment under the condition of motion control, stable combustion for a long period of time, reduce voltage control, security applications, implements the main torch complex system of safe and reliable to use.