Correct answer: B. Carbon dioxide made of ice
Was the ice of the skating rink ever shaved with milk?
Why is the ice in the skating rink milk shaved? Video source: CCTV
Put water and milk in the refrigerator at the same time to freeze into ice cubes and milk cubes, take a bite and what will you find?
If the ice cube hurts tooth, if you bite hard, the ice cube will break immediately, and the milk cube is much "softer" than the ice cube because of its oiliness. So in the past, people usually added milk to the ice of the ice rink to reduce the scratches of the ice knife on the ice surface, thereby reducing post-maintenance.
However, this is also the old way more than a decade ago, and modern ice rinks have long used various technical means and additives to replace milk.
The Chinese speed skating team trains at the National Speed Skating Hall "Ice Ribbon" to prepare for the Beijing Winter Olympics. Image source IC photo
At the 2022 Winter Olympics, the mainland for the first time adopted carbon dioxide transcritical direct cooling technology on a large scale to make the "fastest ice". After simulation and analysis, the use of carbon dioxide transcritical direct cold ice technology, the ice surface temperature difference can be controlled within 0.5 °C, compared with the traditional way, not only the efficiency can be increased by more than 20%, the refrigeration is more uniform, there will be no different temperatures in various parts, uneven hardness of the ice surface. It is understood that this is currently the world's most environmentally friendly ice technology, carbon emissions tend to zero, help to create the fastest, most environmentally friendly ice surface.
The only new ice competition venue for the 2022 Beijing Winter Olympics - "Ice Ribbon"
Multinational athletes train in the "Ice Ribbon". Beijing News reporter Tao Ran photographed
The National Speed Skating Hall, also known as the "Ice Ribbon", is the only new ice competition venue in this event, and together with the "Bird's Nest" and "Water Cube" to form the landmark building complex of the "Double Olympic" City.
"Ice Ribbon" is the first speed skating venue in the history of the Winter Olympics to use carbon dioxide as a refrigerant, and will undertake the competition of speed skating events, producing 14 gold medals, which is the single venue with the largest number of gold medals produced by the Winter Olympics.
Comprehensively compiled from CCTV, China Weather Network, Beijing News previously reported
Edited by Dai Wenjia Proofreader Zhao Lin