Sep 24 2007
Researchers from the Lavochkin Research and Production Association have invented a way to preserve snow on the mountain-skiing and racing routes, even in warm weather. The artificial cooling systems, which are being developed by the researchers, are based on the use of specially-constructed heat pipes. The authors suggest that such a system could be used during the Olympic Games in Sochi – a town known for its uncertain weather.
The principle of operation of these heat pipes is well-known. Simply speaking, it is as follows - in the closed space (in a long and narrow pipe), heavily heated gas turns into liquid and evaporates again. However, these processes are spatially separated. At the one end, in the heating zone, the liquid evaporates – the process requires energy consumption, i.e., it goes with absorption of heat. At the other end, in the cooling zone, the liquid condenses thus cooling the ambient space. Therefore, heating one end of a long pipe can cool the other end.
The question arises how to make the liquid return back to the evaporation zone. If this is a heating pipe, which helps, for example, to cool the house foundation in the permafrost area (so that the house did not “drift” in summer), the device is placed vertically, and the liquid simply flows down by force of gravity. But what can be done if the pipe is place horizontally or it is curved as an arch under the mountain-skiing route?
“Outer space experience” helped the researchers to solve the problem – they specialize in how extraterrestrial objects operate in weightlessness, without help from terrestrial gravitation. The researchers tried cutting superfine capillary grooves on the inside walls of the pipes. This capillary structure allowed the liquid into the evaporation zone at any position of the pipes in space – because capillary forces act independently of the capillary's orientation. Long grooves with a width of less than a micron were created using techniques developed by colleagues of the “outer space engineers” – at Bauman Moscow State Technical University.
To cool the condensation zone, the researchers used special devices called Peltier coolers (elements) named after Jean Charle Atanase Peltier who discovered the heat release or absorption effect when electric current runs through a switch connection of two metals, alloys or semi-conductors. These elements allow the necessary cooling in the condensation zone with low electricity consumption, which makes the entire system very economical. If the thermal conductivity of heat pipes is higher than that of gold and copper is taken into account, the system is extremely efficient. this system is also secure, weighs little and is reliable, as it has no movable parts. It should be particularly emphasized that this is an original Russian technology protected by patents.
More than 500 devices have been put into operation. Their advantage is high reliability as the pipes are placed one metre apart, and if one or more devices breaks down, it does not adversely affect the entire system. All devices are identical in construction, and each can regulate temperature independently.
In the future, these techniques will be used for the Olympic Games, establishing a common artificial climate system controlled from a single centre. We expect that the Olympics 2014 in Sochi will be covered by crisp frosty snow, even if grass grows green and crocuses bloom in the vicinity. This is thanks to the system designed by the researchers from the Lavochkin Research and Production Association.