Research On The Formation Of Annular Flow In Horizental Pipes In Air-Oil Lubrication System

Along with the increasing growth of modern industrial production level, the requirement to mechanical industry is higher and higher. At present, mechanical products is developing towards high-speed, high-efficiency, energy-saving, high level of automatism and long working life, requirement to the effect of lubrication is grown on. Oil-air lubrication is a new lubrication style developed to fit the requirement in new period. It synthesized the characteristic of both air and liquid lubrication, and plays double function in cooling and lubrication. Air-oil lubrication can supplies oil continuously, quantitatively, slowly and uniformly to lubrication points, and then maximally enhance the working life of lubrication points. At the same time, Oil-air lubrication also has the advantage of low oil consume, small pollution to environment and high level of automatism. It has applied in many industrial fields, and obtained good benefit.Annular flow is the flow pattern in oil and gas transmission pipeline in Oil-air lubrication working condition. The main reason that can not master the core technologies of Oil-air lubrication in China is can not recognize the formation mechanism of annular flow profoundly enough. Therefore, this topic aims at developing a Oil-air lubrication system with independent intellectual property right and relevant key components. The main studies are as follows:(1)The math model of annular flow is set up based on the basic equation of fluid mechanics, combining its characteristics; the annular flow pressure drop, liquid membrane thickness and the gas rate of section calculation method are also given in the paper.(2)Through the high-speed photography method, we get instantaneous distribution images of gas and liquid in oil-gas mixer and flow type viewing section, judging the flow pattern in the pipe under different gas-liquid flow according to this, and concluded the change rule of flow pattern; We focuses on analyzing the two-phase interaction when it is annular flow, and puts forward a new formation mechanism of annular flow.(3)Carry out the numerical simulation of internal flow field of oil-gas mixer by using fluid simulation software FLUENT, research on the characteristics of gas-liquid two phase flow and then judge the flow pattern, finally compared it with flow type figure. Analyze the different two-phase volume fraction distribution figure and pressure distribution, velocity distribution circumstance under different gas and liquid flow. Then enrich and perfect the formation mechanism of annular flow indicated by the experimental results.