Abstract
This paper presents the optimization study of a rotary gas separator (RGS) in ESP systems by improving the performance of the inducer part of the RGS. Using two-phase flow inducer model, sensitivity studies were performed to three inducer blade geometrical variables, i.e., tip diameter, pitch length, and total number of pitch, to evaluate the inducer performance in terms of head generation and gas handling capacity.
These studies show that the inducer performance is sensitive to the blade tip diameter and pitch length. Increasing the blade tip diameter and pitch length enlarges the inducer cross sectional area, which in turn increasing the liquid deceleration. This mechanism is responsible for increasing the head generated by the inducer and the sustainability of the inducer in handling free gas. These studies also indicate that increasing the total number of pitch causes detrimental effect to the inducer performance.
These findings suggest that the tip diameter should be made as large as possible within the tolerable size of the pump housing. Similarly, the pitch length should be extended as long as possible within the mechanical integrity tolerance of the whole RGS assembly.
The implementation of the inducer performance sensitivity study results on a typical 400 series RGS indicates that the RGS performance can be improved by enlarging the inducer blade tip diameter and the pitch length. However, the improvement becomes marginal as the gas-liquid ratio increases, which might indicate the limitation of the 400 series RGS application.
