Study of Road Snow Melting Using Exhausted Heat of Vehicle( 1 ) - Laboratory Experiments and Their Application Prospects 2000-01-3484

This study aims to develop a device for melting road snow by dropping hot water using exhausted heat of a vehicle, so as to recover the driving force on frozen road, especially at crossings and slopes.

In the laboratory experiments, torque of model tires driving on a mock road of snow-and-ice sheet were measured together with the melting rate of the snow-and-ice, varying tire speed and hot water dropping procedures, and heat balance of this experiment was calculated. As a result, 8ml of hot water of 80 degree Centigrade was required until the tire contacts with the road surface by removing the 10mm thick snow-and-ice sheet. In the actual case, 8ml for the model tire corresponds to 400ml of hot water dropping on a driving tire, and 10mm thickness of snow-and-ice corresponds to that frozen in the coldest night in Sapporo, Japan.

Simulation studies of snow melting by hot water dropping were carried out for 3 representative cities in Japan for 23 winter seasons. Watching a wheel truck of 0.5m widths and 7.5m lengths, hours for which snow-and-ice was cleared (cleared time) were calculated under the condition that the hot water was dropping during the time from 6:00 to 21:00 at a given rate. As a result, it has been shown how much the ratios of the cleared time to non cleared time in a season decrease with increasing the amount of hot water dropping. The ratios increase and saturate with increasing hot water dropping. At no dropping, they have 10% in Nagaoka, 40% in Sapporo and 85% in Sendai at maximum snow year. They are increase and saturate to 72%, 85% and 93% at 12 l/h, respectively. These values which correspond 30 vehicle dropping hot water of 800ml at a crossing and a slop seem increasing a great advance in solving traffic problem in winter city.