Summer Solar Heat Stored in Ground for Snow Melting during Winter

Many cities and towns in Japan use groundwater or heated water to melt snow and ice on roads during the winter. As an alternative, a unique construction method to store summer solar heat in the ground for snow melting was introduced in 2006 for the replacement of the Saiwai Bridge over the Asuwa River, flowing through Fukui City.

This replacement project required measures against snow and ice on the bridge surface, but additional pumping of groundwater in the central city would be difficult and electrical snow-melting equipment would be costly to operate. In order to solve these problems, the Snow Management and Construction Technology Research Center of Fukui Prefecture invented a new method to store summer heat for snow-melting in winter by driving a large number of dedicated heat-exchanger piles into the riverbank, and developed a new technology in collaboration with University of Fukui, Osaka University and other academic institutions.

This is a closed-conduit system, in which heat-radiating pipes built in the bridge surface and 378 piles (42 rows and 9 columns) embedded 1.5 meters apart into the riverbank are connected through a circulation pump. During daytime in summer, the circulation pump operates automatically as the bridge surface becomes hot, carrying the heat to the underground storage piles. This system warms to 35 degrees Celsius a section of the riverbank measuring 15 meters wide, 64.5 meters long and 23 meters, and maintains the temperature until December for snow melting.

Counting emissions from construction and 50 years of operation, this new technology will result in one-twenty-fifth the carbon dioxide emissions compared to conventional electric snow-melting equipment.



Posted: 2007/09/23 03:15:49 PM
Japanese version