Research On Airlift Pump Simulation

The air-lift pump transports liquid by injecting compressed air into the riser pipe to generate a pressure difference between the pipe pressure and the hydrostatic pressure.Since the air-lift pump does not have the mechanical structure and transmission components which in the traditional pumps,the air-lift pump is not prone to failure with high reliability.Air-lift pump is widely used to transport high-level radioactive materials in the process of spent fuel reprocessing.As an important fluid transport device in the process of spent fuel reprocessing,the study of its simulation is of great significance to the simulation of the spent fuel reprocessing system.The main research contents of this paper are as follows:(1)The physical structure of the air-lift pump is analyzed,and the structural parameters that affect the performance of the air-lift pump are determined.The air-lift pump is divided into a single-phase flow section and a two-phase flow section based on the air injection point.The pressure loss caused by the single-phase flow and the two-phase flow in these sections is analyzed separately.The local loss at the entrance of the single-phase section and the acceleration loss of the two-phase flow section,as well as the influence of the expansion of air in the riser pipe on its performance,are discussed,and a complete momentum balance equation of the air riser is constructed.(2)Analyze the characteristics of the vertical upward two-phase flow in the air-lift pump under different diameters in the working range.Divide the air-lift pump simulation model into large pipe diameter model and small pipe diameter model.Discuss the calculation methods in void fraction and friction pressure drop of the two-phase flow with different applicable ranges based on the separated-phase model.The momentum equation is solved by the iterative method and uses Fortran to code a calculation program.(3)The air-lift pump test bench was designed.The experimental data were obtained in experiments on four pipe diameters of 10 mm,20mm,30 mm,and 40 mm under 3 submergence ratios through this air-lift pump test bench.The efficiency of the air-lift pump is analyzed through experimental data and phenomena.The suggestions for the selection of the air-lift pump in engineering are put forward.(4)By comparing the calculation results of different models with the average relative error of the experimental data,the air-lift pump model with better simulation accuracy was obtained,and the second-level air-lift simulation model was compiled on the basis of this model.