Characteristic Analysis And Optimization Design Of Gas Driven Liquid Booster Based On Lumped Parameter Method

Gas driven liquid boosters are apparatus that use low pressure compressed air as drive medium to realize high output pressure by reciprocating automatically. They utilize the advantages of pneumatic drive and hydraulic drive, the principle of increasing pressure is by use of two different force bearing area of pistons at each independent volume to translate the low air pressure at the side of the large piston area to high hydraulic pressure at the side of the small piston area. The bigger ratios of the areas, the higher output pressure by the gas driven liquid booster. Gas driven liquid boosters have the advantages of compact structure, small size, low cost, high output pressure, reliable working safety, so they are widely used in the field of machine tool industry, oil and gas industry, chemical and petrochemical industry, national defense industry, mining industry, construction machinery and aerospace industry and have come to a hot topic of research on the gas and liquid pressurization technology.The domestic researches on gas driven liquid boosters have been started later, there are not many available research results about gas driven liquid boosters working at high pressure environment. So gas driven liquid boosters with the qualities of large flow and high pressure ratio are deeply researched in the thesis based on mathematical modeling, simulation and experimental study. Firstly, an integrated valve type of gas driven liquid booster is presented, then the simulation model of the system is determined. The influences of different factors of this gas driven liquid booster are analyzed in detail and some conclusions are presented for the improvement of performance of booster. Lastly, the structural parameters of this booster are optimized. The simulation and experimental results show that output pressure is 381 Bar, rated flow can be 23 L/min when air source pressure is 5 bar. The main content of each chapter is summarized as following:In chapter 1, the background and significance of this research about gas driven liquid booster are introduced. The research status is analyzed. The keys and main research work of this thesis are developed.In chapter 2, the working principle of gas driven liquid booster is analyzed, from the output of system and the dynamic response characteristics, the structure of this booster is analyzed and designed, then the basic structural parameters are identified.In chapter 3, the mathematical models of air cylinder and four way two position gas control valve are established by theoretically analyzing the system.In chapter 4, complete simulation models are presented by mathematical formulas. Based on MATLAB/Simulink, the effect of the air source pressure、structure of control valve and air cylinder, loading pressure for the dynamic performance is discussed. Lastly, the optimized parameters are presented.In chapter 5, the basic principle of flow rate characteristic test system and the output pressure test system are introduced. Bases on these systems, the flow rate and the output pressure of the proposed booster are measured and compared with the simulation results. The result indicates the simulation models are correct.In chapter 6, the full texts of the main work are summarized and the further research work is prospected.