Overview of Ionic Liquids as Candidates for New Heat Transfer Fluids

Abstract

This review discusses, in terms of practical aspects and future application, about heat transfer fluids properties with special focus on the possible use of ionic liquids in heat transfer applications. Even if some data were identified in the open literature, most of the ionic liquids studies on thermophysical properties are yet at the beginning and fully described chemicals are scarce. The most relevant thermophysical properties of ionic liquids (density, specific heat, thermal conductivity, and viscosity) are paralleled with the properties of several commercial heat transfer fluids. A consistent attention is paid to the analysis of heat transfer coefficient and friction factor, as well as Prandtl number. Concluding, ionic liquids can be seen as an alternative to regular heat transfer oils, however, a consistent experimental approach using real-life geometries and conditions is mandatory to be developed to fully understand all the processes.