De-icing Test of the Externally Heated Geothermal Bridge in Texas

Abstract

In recent years, a geothermal heat pump de-icing system (GHDS) has been introduced as an alternative for conventional snow and ice removal systems (CSRS). Application of the CSRS for bridges highly prone to ice formation is not a satisfactory solution as it has a negative impact on the environment, bridge deck condition, motorist safety, and travel time. Although GHDS has proved to be a sufficient and feasible solution, it is only applicable to new bridges. However, a new method of GHDS has been developed which utilizes an external hydronic pipe attached to the bottom surface of the bridge deck and is applicable even for existing bridges. In this study, the performance of the external hydronic heating system, installed and tested on the full-scale mock-up bridge deck, was investigated in Texas. The system has experienced several cold events and de-icing tests, in which it was successful in maintaining the surface temperature above freezing. However, the results show the system is capable of de-icing the bridge deck and provide an ice-free surface. In order to enhance the de-icing operation, the system requires about 8 h of preheating; however, less time is required during mild events. Furthermore, the system is energy-efficient with a coefficient of performance (COP) of more than 4.KeywordsExternally heated bridge deckGeothermal heat pump systemBridge deck de-icingSnow meltingDe-icing systemGeothermal energy