CFD Simulation of Fluid Flow and Heat Transfer in a Counter-current Reactor System under Supercritical Conditions

Abstract

Continuous hydrothermal flow synthesis (CHFS) system can produce high quality fine nanoparticles. However, optimisation of the CHFS system including the reactor and heat exchanger design, and its scale up for commercial applications have not been studied and cannot be achieved only through laboratory and pilot plant experiments. In this paper, computational fluid dynamics (CFD) was applied to simulate fluid flow and heat transfer in a counter-current reactor and a tubular heat exchanger of a CHFS system for the production of TiO2 nanoparticles. The distributions of flow and heat transfer variables such as velocity and temperature in both units were obtained using ANSYS Fluent package. The simulated temperatures in both the reactor and the heat exchanger are compared with the available experimental data, which reveals that a good level of agreement is achieved. The present study demonstrates that CFD modelling can be a useful tool for the prediction of fluid flow, mixing and heat transfer in counter-current reactors and heat exchangers used in CHFS systems, and also for the design optimisation and scaling-up of such systems.