Investigation On The Inner Gas-Liquid Flow In Liquid-Ring Pump And It’s Performance

Liquid ring vacuum pump is widely used in petroleum, coal, chemical, metallurgy and other fields.because of its advantages of large flow rate, compact structure, and isothermal compression. In recent years, the complex internal gas-liquid flow in liquid ring pump and its performance optimization were the popular topics in the hydraulic machinery area. In this paper, the numerical simulation of the complex internal gas-liquid flow and the experimental research about the characteristics in the liquid-ring pump have been studied,and the main work is as follows:1. Since SZB type liquid ring pumps have unique structural characteristics, so the paper choose SZB type liquid ring pump as the research prototype. Based on the theoretical analysis of fluid movement and the inner shape of liquid ring, the inner boundary of the liquid ring pump is calculated by using Matlab, and compared with the results of numerical and experiment method.2. There are unsteady gas-liquid interface and complex secondary flow structure in the gas-liquid two-phase flow of liquid-ring pump. Several numerical methods about the free interface and the interface reconstruction in the gas-liquid flow are introduced in this paper.Compared of these methods, this paper chooses VOF method for the numerical calculation of internal flow in liquid-ring pump. The mathematical principles and several interface reconstruction methods of VOF method are introduced in this paper.3. Finite volume method is used to discrete control equation. VOF gas-liquid two phase model is used to simulate the3D unsteady gas-liquid two phase flow. Gas-liquid interface is traced. The influence of imported vacuum degree on the change of gas-liquid free interface is analyzed. This paper has analyzed streamline distribution, velocity distribution, pressure distribution and phase distribution and complex secondary flow in liquid ring pump by numerical calculation method. The numerical results and the experimental results show good agreement. The numerical method of VOF is suitable for simulating the gas-liquid flow in liquid-ring pump. The free interface can be traced exactly and the hydraulic performance can be evaluated with enough accuracy. The present study provides evidence for mastering the internal flow mechanism of liquid ring pump and provides a basis for performance optimization.