| Oil-gas multiphase belongs to the most advanced oil-gas drilling technology, oil-gas multiphase pump is one of the key equipments in the process. Due to the complex working conditions of oil-gas mixing transportation, the traditional multiphase pump have the problems of low efficiency, gas recovery difficulty, poor reliability and gas resistance and so on. To solve these problems, this paper puts forward a new internal compression rotor oil-gas multiphase pump, and also sets up three groups of ball valve to make it have a special internal compression function. Thus, it can further adapt to the two-phase conditions, and improve the compression ratio and pump efficiency. Given that the related research of the rotor oil-gas multiphase pump is still at the initial stage, the theoretical analysis and numerical simulation calculation on the pump input power has been carried on separately, export ball valve motion laws of dynamic characteristics, the change of structural parameters of valve group and valve ball bearing. The working characteristics and change laws of the pump and export ball valve have been revealed preliminary to provide reference for theory analysis and design of the pump in the complex oil-gas ratio conditions. The main research work and conclusions are as follows:1. Through the analysis of the structure characteristics and an internal compression process for the new rotor pump, theoretical calculation formulas about rotor pump input power, additional power input and no internal compression function pump input power are received. Combining with the practical example calculation, in different compression ratio (changing the suction pressure and discharge pressure respectively) and oil-gas ratio working conditions, change laws of compression rotor oil-gas multiphase pump input power are analyzed.2. Using MATLAB software and the runge-kutta method, it apply mathematical calculation to solve ball valve lift and the speed curves. Then, based on the actual structure and the working parameters, the geometry model of the rotor pump and valves is established, and simulation is calculated using the FLUENT software. The numerical simulation curves and mathematical theoretical calculation curves are comparatively analyzed.3. The effect of export ball valve structure parameters and physical properties on motion characteristics of valve ball and valve gap flow field are further analyzed. Changing valve seat half cone angle and inlet diameter, numerical simulation are carried out on valve ball speed and lift. Valve gap pressure field, velocity field distributions are presented in the process of conveying oil-gas media with structure parameters changing. At the same time, combining with the calculation model of ball valve flow coefficient, the relationship curves between the structure parameters of the valve group, oil-gas ratio and flow coefficient are obtained.4. Put forward on the optimized plan for the ball valve, adding spring on ball valve. Changing oil-gas ratio, the spring stiffness coefficient (1000～4000N/m) and four kinds of valve ball material to analyze valve ball bearing and obtain changing laws of ball valve motion parameters. These conclusions also provide reference for the selection and design of ball valve. |
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