Numerical study of the thermal behavior of a new deicing road structure design with energy harvesting capabilities
Abstract
Facing the heavy organisational, financial and environmental constraints imposed by usual winter maintenance
salting operations, pavement engineers have been led to look for alternative solutions to avoid ice or snow deposit
at pavements surface. Among the solutions, one is self-de-icing heating pavements, for which two technologies
have been developed so far: one is based on embedded coils circulating a heated calorific fluid under the pavement
surface; the other one relies on the use of embedded resistant electric wires. The use and operation of such systems
in the world is still limited and was only confined to small road stretches or specific applications, such as bridges
which are particularly sensitive to frost. One of the most significant “coil technology” example in Europe is the
SERSO-System (Solar Energy recovery from road surfaces) built in 1994, on a Switzerland bridge. Many of
these experiences are referenced in the technical literature, which provides state-of-the art papers (see for instance
Eugster) and useful detailed information dealing with the construction and operational management of such
installation.
The present study is taking part of the Forever Open Road Concept addressed by the R5G: 5th Generation Road
, one of the major project supported by IFSTTAR. It considers a different design of self-de-icing road that
simplify its mode of construction and maintenance, compared to the two technologies mentioned above. It should
also be noted that similar to pavements instrumented with coils, such structure could be used in the reversible way
to capture the solar energy at the pavement surface during sunny days and store it, to either warm the pavement
at a later stage or for exogenous needs (e.g. contribution to domestic hot water). To complete our study we also
considered the use of semi-transparent pavement course wearing in place of the traditional opaque one.
In the present study, a 2D model was developed using FEM approach. It combines 2 numerical models. One
is dedicated to the calculation of the heat transfer inside the porous layer between the fluid and the structure
according to the geometry studied and the physical properties of the components of the system. The second one
addresses the heat transfer inside the different layer of the pavement and was adapted to allow the insertion of a
semi-transparent surface layer (for sun radiation). The temperature spatial distribution within the structure and its
surface is calculated at different time step according to the evolution of boundary conditions at its surface. Various
location in France were selected and calculation of the temperature field was carried-out over a year. Discussion
on the performances of such system versus its location is proposed. Influence of a semi-transparent layer is also
discussed. Future works will compared numerical simulations with experiments thank to a dedicated test bench
under development and that will allow to test various structure in parallel.
Origin : Files produced by the author(s)