Heat Exchangers for Heavy Vehicles Utilizing High Thermal Conductivity Graphite Foams

Abstract

<div class="htmlview paragraph">Approximately two thirds of the world's energy consumption is wasted as heat. In an attempt to reduce heat losses, heat exchangers are utilized to recover some of the energy. A unique graphite foam developed at the Oak Ridge National Laboratory (ORNL) and licensed to Poco Graphite, Inc., promises to allow for novel, more efficient heat exchanger designs. This graphite foam, <span class="xref">Figure 1</span>, has a density between 0.2 and 0.6 g/cm<sup>3</sup> and a bulk thermal conductivity between 40 and 187 W/m·K. Because the foam has a very accessible surface area (> 4 m<sup>2</sup>/g) and is open celled, the overall heat transfer coefficients of foam-based heat exchangers can be up to two orders of magnitude greater than conventional heat exchangers. As a result, foam-based heat exchangers could be dramatically smaller and lighter.</div>