چكيده به لاتين
Abstract
In simulation of the bubble column defined in this research, the Eulerian-Eulerian framework has been used. Also, turbulence in the liquid phase has been calculated through modification of equations using the additional parameter for interphase turbulent momentum exchanges. For dispersed phases, the effects of the turbulence relation were applied through the relations derived from the particle dispersion theory. Studies shown that the selection of existing coalescence and breakage models improved simulation results about 25%. In following study, quantitative comparisons with experimental data were performed and it was shown that the CFD model with the population balance equation, compared with the use of the mean size for the bubble, provided a more accurate prediction of the behavior of the system and reduces the resulting error to 13.8%. Also, by comparing standard and RNG disturbance models, it was concluded that using the RNG disturbance model reduces the error up to 16%, and thus provides more accurate results on the fluid velocity and the mean size of the bubble. Also, in results of the simulation of the three-phase water-oil-bubble system, it was observed that by increasing the concentration of 100 ppm, 600 ppm and 900 ppmoil in the system, the separation rate increased from 47.23% to 59.17% and 66.9%, respectively. In order to express the importance of the interactions of the three phases of water-oil-gas on the separation process, simulation was performed without considering these effects and the contour of the results of the separation was presented; based on the results, the seperation would be negligible without considering the interactions. Finally, it was concluded that in addition to the fluid concentration, other parameters such as turbulence intensity, turbulent kinetic energy, carrier bubble size, and continuous and dispersed phase density will also affect the separation.
Keywords: Computational Fluid Dynamics (CFD), BubbleCoalesance and breakage, Bubble Population Balance Equation (BPBE), Two-phase Bubble Column, Multiphase Flow.
