Effect of Diversion Cavity Geometry on the Performance of Gas-Liquid Two-Phase Mixed Transport Pump

Abstract

For the purpose of improving the transport capability of the mixed transport pump, a new self-made three-stage deep-sea multiphase pump was taken as the research object. Based on the Euler-Euler heterogeneous flow model, liquid (water) and gas (air) are used as the mixed media to study the external characteristics and internal flow identities of the mixed pump under different gas volume fraction (GVF) conditions. According to the simulation results, a local optimal design scheme of the diversion cavity in the dynamic and static connection section is proposed. The numerical results before and after the optimization are compared and analyzed to explore the effect of the diversion cavity optimization on the performance, blade load and internal flow identities of the pump. The results show that the head and efficiency are obviously improved when the inner wall of the diversion cavity is reduced by 4 mm along the radial direction. After optimization, under the condition of 10% gas content, the head and efficiency is increased by 3.73% and 2.91% respectively. Meanwhile, the hydraulic losses of the diversion cavity and diffuser are reduced by 9.11% and 4.32% respectively. The gas distribution in the impeller is improved obviously and the phenomenon of a large amount of gas phase accumulation is eliminated in the channel. In addition, the abnormal pressure load on the blade surface is eliminated and the turbulent flow energy intensity is reduced. The average turbulent kinetic energy ( T K ) at i = 0.51 of the first stage impeller passage is reduced by 35%. Finally, the reliability of the numerical method is verified by the experimental results. To sum up, the performance and internal flow identities of the optimized mixed transport pump are improved, which verifies the availability and applicability of the optimization results. This provides a reference for the research and design of a multiphase mixed transport pump in the future.

Numerical investigation on slip velocity characteristics of gas-liquid two-phase flow in a multiphase pump under different blade tip clearance

“…The Euler-Euler inhomogeneous hydrodynamic model was provided for numerical calculation, which considered not only velocity slip, but also momentum transfer and interphase force. According to the research of Li et al's [6,7], two turbulence models were used to solve different media, among which the SST k-ω model was selected for continuous phase, and the Discrete Phase Zero Equation model was selected for discrete phase.…”

Flow Characteristics and Energy Loss within the Static Impeller of Multiphase Pump

“…Experimental results show that, for the multiphase pump at the pressure difference of 0.4 MPa and 1.0 MPa, the flow rate decreased by 18.7% and 25.7% with an increase of the gas volume fraction from 20% to Processes 2021, 9, 1025 2 of 18 90%, respectively. Chenhao Li [11] based on the Euler-Euler model, used water and air as the mixed media to study the external characteristic and internal flow of the multiphase pump under different gas volume fractions. LI Chenhao [12] also found that the variation tendency of the pressurization capacity in the multiphase pump is uniform from the first stage to the last stage under the gas-liquid two-phase condition, and the pressurization capacity of the last stage is more variable with different gas volume fractions.…”

Effect of the Gas Volume Fraction on the Pressure Load of the Multiphase Pump Blade

“…Liu M. et al [18] also proposed a hydraulic design approach of a controllable blade angle oriented with a multiphase pump based on an impeller and diffuser; the results revealed that the distributions of GVF as well as the pressure would be of more uniformity following the optimization, thus enhancing transporting performance of the pump. Li C. et al [19] carried out research on the outer features and inner flow identities of the multiphase pump amidst various GVF circumstances on the basis of the Euler-Euler heterogeneous flow model. The results offered showed that the head and efficiency presented obvious improvement when the reduction of the inner wall of the diversion cavity occurred to 4 mm to the radial direction.…”