"Snow sports competition venues are mostly in mountainous areas, and the ambient temperature may reach below minus 10 degrees Celsius..." How can the audience warm the spectators watch the game in extremely cold conditions? How can staff and spectators avoid frostbite and get "warmth guarantee"?
In order to solve this problem, the team of Cao Bin, associate professor of the School of Architecture of Tsinghua University, participated in the national "13th Five-Year Plan" key research and development plan "Science and Technology Winter Olympics" key special project "artificial profile track venue new construction, maintenance and operation technology" project, and developed a "warm equipment" in an extremely cold environment - intelligent heating suits and heating cushions, which can quickly heat up and lock heat in a short period of time to ensure that the audience has a comfortable and warm viewing experience.
The reporter learned that focusing on people's needs and feelings and collecting relevant data to assist in design is a relatively new concept in the entire field of large architecture. Cao Bin said that according to the needs of the event and the venue, it is hoped that the research results will be applied in some areas as appropriate in the future.
Extremely low temperatures create new challenges for research
Cao Bin's major is the department of building environment in the School of Architecture, focusing on how to solve the problems of building environment creation and improving people's comfort in the environment.
"Before, it was all about how to create the environment in the building and indoor scenes, while the snow sports venues were open-air and open, and the traditional methods and technologies for indoor space were not applicable before; and the open-air arena environment was more extreme, and there were few research results that could be learned from the physiological data of people in extreme environments." Cao Bin said that for the research team, because the application scenarios and objects are new, it can be said that it has entered a new research field, which is also the biggest difficulty of this research.
The research team studies the tests in the field. Courtesy of respondents
Cao Bin told reporters that the first problem faced by this study is to understand how cold people will be if they stay in a low temperature environment of more than ten degrees Celsius for one or two hours.
For scientific research, it is not enough to have people's intuitive feelings, but to need specific and objective parameters. Therefore, Cao Bin's team went to the field in the winter to record environmental parameters, and then simulated the environment in the low temperature environment cabin, and conducted subject experiments, through temperature sensors, monitoring the skin temperature of multiple parts of the human body after being exposed to different times in the low temperature environment, in order to assess "how cold people will be."
In addition to the human subject experiment, Cao Bin's team also used the "warm body dummy" device to collect data. It is reported that this "dummy" is a robot, but it looks completely human form, each part of its body can simulate the heat generation and heat dissipation of real people, and at the same time, through the background program software, monitor different exposure time, different thickness of clothing, dummy surface temperature changes.
The research team used warm dummies to conduct field experiments in low temperature environments. Courtesy of respondents
Develop an experimental system to collect human body data
After knowing how cold people are, the next step is to add calories to people.
Cao Bin explained that because in the open environment, the heat will continue to dissipate, and the conventional method of heating and keeping warm in enclosed spaces cannot be used. Therefore, from the theory to the solution, this research follows a line of thinking - to consider the problem from the individual scale of people, to give all the heat to people.
So, how much heat do people need in extreme low temperature environments, and which parts of the people should be given to add calories to be the most effective and comfortable? Cao Bin told reporters that this requires studying the sensitivity of various parts of the human body to heat in cold environments to come up with an answer.
In order to solve this problem, Cao Bin's team developed a "human body multi-point heating experimental system", consisting of a set of "heating clothes" and background programs. The "heating suit" looks like a thin set of intimate clothes with heating flakes on various parts, while you can control and interact with them on the tablet.
After the subject puts on the "heating suit", the program interface can see and select different parts and set different heating temperatures. "For example, if you want to heat your abdomen to 35° C, or heat your legs to 37 degrees, you can set it up at the program interface, and then the heating suit will be heated according to the program settings." Cao Bin said.
By conducting a certain number of experiments on real subjects, Cao Bin's team summed up the rules and found which parts of the body people generally tend to heat in a long-term low temperature environment, and how many degrees Celsius will be heated to achieve a more comfortable state.
Smart vests and cushions give people efficient heat replenishment
After the preliminary research is completed, the last step is to make the heating equipment into a physical object according to the theoretical data. Following the "individual scale" idea, Cao Bin's team finally decided to adopt a wearable way to achieve this measure.
After much deliberation, the team finally developed two forms of equipment - one is a portable heated cushion, and the other is a smart heated vest that can be worn on the body.
Intelligent heating and heating equipment developed by the team. Courtesy of respondents
The principle of these two equipment is similar, both use flexible graphene heating materials, through its electric heating effect, after the power can be effective heating; and the material itself is soft, people sitting on it to produce deformation does not matter.
"If you don't think about keeping warm, the heat dissipates quickly." In an open environment, in addition to heating, heat preservation is also very important. In terms of thermal insulation performance, Cao Bin's team adopted a light and thin insulation material superposition, placed on the bottom of the cushion and the outer layer of the vest, to block the downward and outward dissipation of heat, to ensure that heat is concentrated and efficiently transmitted to people. "The surface temperature on the cushion can reach more than 40 degrees Celsius, and because of the thermal insulation properties, if you touch its lower surface, you will find it very cool." Cao Bin said.
Regarding wearable heating equipment, the reason why it is made into a vest form instead of a coat, Cao Bin explained that the vest is more flexible and close-fitting, which is convenient for everyone to match their own coats, and it is also more conducive to the effective use of heat. At the same time, this vest is also equipped with a mobile phone mini program, the user can interact with themselves, through a concise schematic diagram to select the heating part and adjust the temperature.
In addition to striving to serve the Winter Olympics, how can these research results be applied? In this regard, Cao Bin told reporters that with the popularization and development of ice and snow sports in China, there will be more and more events and participants, and the demand for heating and heating solutions will also increase; in addition, there are many scenes of outdoor extreme low temperature environment and harsh natural conditions, and it is hoped that these research results can continue to be promoted.
Beijing News reporter Feng Qi proofread Liu Jun