Calculation method of heat and fluid flow in a microreactor for supercritical water and its solution

摘要

A microreactor for supercritical water has been developed for chemical engineering process. Heat and fluid flow in a T-junction in this system are calculated using STREAM. Since the flow in the tube are in the wide range from laminar to turbulent flow, a nonlinear k-epsilon model taking into account the low-Reynolds-number effects (proposed by Abe, Kondoh and Nagano) are used. We assume that a supercritical water velocity is 2.0 m/s. The optimum condition for time fluctuation of temperature is when the substrate velocity is 0.4. In this case, the substrate temperature rises above the critical temperature immediately and the main reaction progresses efficiently. When v is 0.1, the temperature remains subcritical region for a while. On the other hand, when the v is larger than 0.4, the temperature does not reach the critical point. (c) 2005 Elsevier Ltd. All rights reserved.