Coupling a Hydronic Heating Pavement to a Horizontal Ground Heat Exchanger for harvesting solar energy and heating road surfaces

Abstract

The traditional method for anti-icing roads is distributing salt and sand. However, the method causes environmental pollution and damages to road infrastructures. A renewable alternative method for winter maintenance of roads is to use Hydronic Heating Pavement (HHP), coupled to a Ground Heat Exchanger (GHE). The aim of this paper is to examine the feasibility of the coupled HHP system to a Horizontal GHE (HGHE) for harvesting solar energy during summer and anti-icing road surfaces during winter. A hybrid 3D numerical simulation model is used to analyze the harvesting and anti-icing operations. Furthermore, a 2D numerical simulation model is used to calculate the heat loss from the HGHE to the surrounding ground. The climate data are obtained from Östersund, a city in the middle of Sweden with long and cold winter period. The results showed that the amount of harvested solar energy during summer is, on average, 99kWh/(m2⋅year). Less than 10% of this energy is lost to the surrounding ground. In addition, the required energy for anti-icing the road surface is 75kWh/(m2⋅year). Applying this amount of energy for anti-icing the road surface results in remaining, on an annual average, 580 h of slippery condition on the road surface.