Road deicing effects using an electrically conductive paint

Pengfei Cao1^{1}, Xiaofeng Guo1,^{1,\star}, Laurent Royon1^{1}
^{\star} :
1^{1} LIED UMR 8236 CNRS Université Paris Cité
Mots clés : De-icing, Road, Electric resistance paint, Heat resistance
Résumé :

Facing the danger of icy roads, different deicing techniques are available with salt spraying being the most dominant one. However, salt deicing has high environmental impacts, reduces the durability of road and it relies on heavy logistical management from salt storage, truck, and planning. The mechanical deicing is also one of the most popular traditional methods, but the emission of the greenhouse gases, not to mention the cost of operator. Remote deicing using road heating can be an efficient alternative. Electrical heating is capable of deicing quickly by heating an electrical resistance like wires. This research introduces the use of a new material for road deicing purpose. The material is an electrical conductive coating directly integrated as a thin layer sandwiched by two asphalt layers. As part of an ADEME project ICCAR, this study investigates the heat transfer behavior for the whole sandwich structure. Both numerical and experimental results are used with granite (6cm*8.7cm*24.6cm) in the place of asphalt. A thin electric resistant layer (coating) integrated between the two granites is fed by two electrodes under different electric powers (250, 350 and 450W/m²) from the Joule effect. The whole equipment apart from the top surface exposed in the air is covered by the insulating material and then put into a climatic chamber with temperature at an average of -22^{\circ}C. The initial temperature of the equipment is stabilized at -19^{\circ}C. The temperatures of the top surface, of the paint, of the bottom granite and of the environment are measured by four thermocouples during the 28 hours of heating ON/OFF cycle. Prior to the measurement, the dependence of electrical resistance of the paint (R) and its temperature (T) has been characterized. The numerical simulation was done with COMSOL 3.5a Multiphysics in 2D geometry. For the heating process, our results show deicing effect for heating rate higher than 250W/m², below which the surface temperature cannot be higher than 0^{\circ}C. At 250W/m², the temperature of the surface increase from -19^{\circ}C to 0^{\circ}C in 16 h with 4.205kWh/m² energy consumption. Steady state surface temperature is 2^{\circ}C. Compared with 250W/m², the time needed, and energy consumed to increase the same temperature for 350W/m² is 8 hours and 2.803kWh/m² and for 450W/m² is 5 hours and 2.336kWh/m², 50

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