Ionic Liquids as Thermal Fluids for Solar Energy Storage: Computer-Aided Molecular Design and TRNSYS Simulation

Due to the great potential of ionic liquid (ILs) for solar energy storage, this work combines computer-aided ionic liquid design (CAILD) and a TRNSYS simulation to identify promising IL candidates as simultaneous thermal storage media and heat transfer fluids. First, a mixed-integer nonlinear programming (MINLP) problem is formulated to search for optimal IL structures, where the thermal storage density integrating the IL density, heat capacity, melting point, and desorption temperature is employed as the objective function and the physical properties, i.e. thermal conductivity and viscosity, are implemented as optimization constraints. After that, TRNSYS simulations of a solar energy power system with the designed ILs as thermal fluids are conducted during a typical meteorological year to further study the practical performance of the IL candidates. Through the analyses of annual system operation performance as well as the long-term cost savings of such a system, the application feasibility and sustainability of the designed ILs for solar energy storage are well interpreted.

Automated summary

This study combines computer-aided ionic liquid design and TRNSYS simulation to identify suitable ionic liquids for solar energy storage as thermal storage media and heat transfer fluids. Mixed-integer nonlinear programming is used to search for optimal ionic liquid structures, and TRNSYS simulations are conducted to study the practical performance of the designed liquids. The results demonstrate the feasibility and sustainability of the designed ionic liquids for solar energy storage.