Computational Investigation of Counter-Current Reactors in a Continuous Hydrothermal Flow Synthesis System for Reactor Design Improvement

Computational fluid dynamics (CFD) is applied to the study of a laboratory-scale counter-current reactor for continuous hydrothermal flow synthesis of nanomaterials. Hydrodynamic and thermodynamic variables including velocity and temperature are modelled using ANSYS Fluent package. The tracer concentration profile is also simulated via solving the species equations in order to investigate the mixing behaviour. The predicted temperatures in the counter-current reactor are found to be in good agreement with experimental data. Based on the simulation, improved designs of the reactor were proposed using shorter insertion lengths of the supercritical water tube. CFD simulation of the new designs is compared with the original reactor design, demonstrating improved mixing and heat transfer performance.