Deicing performances of a road unit driven by a hydronic heating system in severely cold regions of China

Abstract

Abstract The deicing performances of a road unit driven by a hydronic heating system in severely cold regions of China were investigated by using the Open Source Lattice Boltzmann Code. The model used the enthalpy-based method and double distribution functions for the velocity and temperature fields to solve the ice melting problem. The average road surface temperatures and melting conditions (melting ratio and mass) as affected by ice thickness (3 ∼ 20\xa0mm), pipe spacing (80 ∼ 240\xa0mm), and air temperature (252 ∼ 268 K) were detailed, and the parameters were analyzed by the orthogonal test method. The results show that for the ice thickness increasing from 3\xa0mm to 20\xa0mm, the heating rate was slightly increased from 6.3 K/h to 6.45 K/h in the preheating and initial melting stages, and from 1.32 K/h to 2.06 K/h in the rapid melting stage, the melting mass was increased from 360 g/m to 762.06 g/m whereas the melting ratio was decreased from 1.00 to 0.32. The pipe spacing of 120\xa0mm was suitable for the road heating whereas ≥ 160\xa0mm was not feasible in the severely cold regions. For the air temperature was increased from 252 K to 268 K, the preheating time was decreased from 3.02 h to 0.82 h, the heating rate in the melting stages was increased from 0.68 K/h to 2.94 K/h and the melting ratio was linearly increased. The parameter analysis reveals that the air temperature had the most important influence on the melting ratio whereas the pipe spacing had the most significant impact on the average road surface temperature, and the ice thickness had a slight influence on the melting ratio and average road surface temperature.