THERMAL PERFORMANCE OF HYDRONIC BRIDGE-ROAD HEATING SYSTEM

Abstract

 Field experiments were conducted at Ichimido Bridge road in Wadayama, Hyogo prefecture in order to examine the thermal performance of anti-freezing system using river water heat. Objects of temperature measurements were pavement, river water, water in a storage tank, and heat carrier fluid in a heat extraction pipe and water pipes. It can be seen that (1) the pavement temperature with the heating system became higher than that without the heating system when air temperature was below 6.7°C, (2) the frequency of freezing on the road surface with the heating system was reduced by 1/10 compared with the ordinary pavement, (3) thermal energy consumed for the road heating was 20% of the extracted river water heat, (4) the hourly decline rate of bridge pavement temperature with the heating system was two times smaller than that of the pavement temperature on the roadbed near the bridge.