泵理论与技术
WANG Like, LIAO Weili, LU Jinling, LUO Xingqi, RUAN Hui, ZHAO Yaping, WANG Jing
In order to study the influence of gas-liquid twophase flow to a centrifugal pump performance and internal flow patterns, the steady threedimensional flow with different gas volume fractions is simulated by applying the Reynoldsaverage N-S equation and mixture gas-liquid twophase flow model, and the compressibility of gas is taken into consideration in the simulation. Then we emphatically analyzed the centrifugal pump characteristic and the gas distribution law in different gas volume fractions. The computational results show that gas volume fraction has a certain influence on the performance of the centrifugal pump, and the efficiency and head of the pump are on the decline with the increase of it. Static pressure in the impeller increases in the radial direction, but the pressure gradient in the flow direction is different under the different gas volume fractions. The gas volume is distributed mainly in the ipsilateral direction of impeller back shroud in the flow channel of the volute. On the suction side of the blade inlet there is an obvious lowpressure area, which causes bubbles agglutination and higher gas volume fraction. With the gas entering passage flow, gas volume fraction in the suction decreases and the pressure surface rises gradually. Higher gas volume fraction causes air blocking phenomenon in the flow passage and the discharge capacity reduces. The increase of gas volume makes the turbulent motion within the impeller more and more intense, which leads to more and more energy loss.