Zheng Cao

Integration of CFD and RTD analysis in flow pattern and mixing behavior of rotary pressure exchanger with extended angle

AbstractIn this study, the computational fluid dynamics (CFD) approach combined with the residence time distribution (RTD) analysis was implemented to examine the mixing performance and flow pattern of rotary pressure exchanger (RPE). Based on oscillatory Reynolds number, a flow regime classification was established for RPE. A concept of extended angle of RPE was proposed, and then, its effects on mixing behavior were evaluated by CFD simulation in laminar model. Meanwhile, flow pattern in RPE was quantified by RTD study, and was well captured in the flow field analysis. In addition, the effects of operating conditions on the mixing and flow pattern were discussed. According to the results, it was shown that the extended angle of RPE is beneficial for mixing control, and a minimum volumetric mixing rate was achieved when the extended angle is ±30° compared with other configurations. In different operating conditions, the mixing rate was minimized at an oscillatory Reynolds number of about 178. Moreover, t...

Numerical Research of Multi-Scale Coupling Simulation on Rotary Pressure Exchanger and Pipe System

Rotary Pressure exchanger (RPE) is an efficient device which recovers pressure energy from liquid streams in process industries. In this work, a multi-scale numerical investigation of pressure propagation in RPE and the pipeline is carried out. A system model including pipe system and RPE component is firstly presented, and is then solved by the integration of 1-D Method of characteristics (MOC) and CFD method. The simultaneous data exchange between the pipeline and RPE is enabled by making use of the existing programming interfaces. At last, the mutual effect of wave phenomenon in pipeline and RPE is evaluated by the synchronous interaction under transient operating conditions. The proposed multi-scale coupling approach in this work could either provide the internal flow details in RPE device or the dynamic behavior of the system, making the numerical simulation more reasonable with system-level accuracy and time-saving.Copyright