PONDERING THE CHOICE OF PCM AND MATHEMATICAL MODEL IN AUTOMOTIVE LHTS

Abstract

Phase change materials are latent heat storage materials. As the source temperature rises, the chemical bonds within the PCM break up as the material changes phase. Upon storing heat in the storage material, the material begins to melt when the phase change temperature is reached. The temperature then stays constant until the melting process is finished. The heat stored during the phase change process of the material is called latent heat. Ideally, automotive engine cooling is undesirable from the thermodynamic point of view. If the heat transfer rates from the gas to metal could be reduced, then more power could be produced at a particular fuel flow rate, i.e. the thermal efficiency of the engine would increase. Also the heat removed out via radiator could be reduced and hence smaller radiator size. That is why powertrain thermal management is extremely necessary for good engine reliability and durability with a compromise of the thermal efficiency. One of the most technically and commercially available options for this is the use of latent heat thermal energy storage system. Despite the fact that there are numerous works and reviews covering this topic, the author hopes to draw attention to some aspects of the choice of material and mathematical model for such systems. Keywords: phase-change materials, latent heat, energy storage systems, thermal conductivity, thermo-physical properties, kinetic properties.