CFD-Analysis of Heat Transfer and Initiator Mixing Performance in LDPE High Pressure Tubular Reactors

摘要

Computational Fluid Dynamics combined with accurate physical property data and reaction kinetics provides the opportunity to study important process engineering problems in detail. In this study CFD is applied to both heat transfer and mixing in high pressure tubular reactors for LDPE manufacture. Two very important physico-chemical processes occurring in these reactors are a) the rapid mixing of initiators with the bulk ethylene/polyethylene mixture, and b) the efficient removal of heat from the reaction mixture. Simulation results are compared with standard values for the heat transfer coefficients. Significant differences were found for the polymerization section along the tubular reactor. In this part of the reactor mixing plays an important role for initiator efficiency and the formation of product characteristics. By use of the four environment CFD micro-mixing model the initiator efficiencies for a common peroxide initiator and appropriate reactor stability curves were calculated.