Study On "L" Porous Buffer Oil Feeding Process

With the rapid development of automobile industry, the fuel filling stations are more competitive. Exploring how to ensure the quality and safety of oil, reduce the waiting time for customer during unloading, improve service levels and competitiveness have become the urgent problem of refined oil retail business to solve. The porous way to oil unloading used by "L" shaped porous buffer inlet pipe can effectively reduce the impact and agitation to the impurities on the bottom of tank; and it also can make simultaneously discharging oil and gas operations realizable.Based on computational fluid dynamics method, internal flow field of the oil tank is numerical simulated by means of FLUENT software. In order to improve the efficiency of unloading oil (reducing turbulent kinetic energy and volume fraction of water), the design parameters of "L" shaped porous buffer inlet pipe are optimized, which have influence on the efficiency of unloading oil. The whole paper mainly carried out the following aspects:(1) The two traditional technology of oil into the tank ("I" shaped oil feeding process and "J" shaped oil feeding process) are analyzed. And the preliminary design scheme of "L’ shaped porous buffer inlet pipe is put forward;(2) In connection with structural features of common30m3buried oil tank, its geometric model is simplified to better analyze. Then, a set of suitable mesh for this model is summarized. RNG κ-ε model was reasonably selected as turbulence model. Similarly, the mixture model is used for multiphase-flow and some simulated conditions are used for calculation as well;(3) Studying on oil flow characteristics in tank under the three different oil feeding process is to deeply analyze the flow behavior that is near to the inlet of oil output pipe. As a result, it shows that "L" shaped porous buffer inlet pipe is feasible and also has some advantages. Combined with numerical simulation, electrostatic generation and the cause of electrostatic accidents are analyzed firstly; then, some preventive measures against static electricity are recommended;(4) Putting more emphasis on the research of the six influencing factors, which are the inlet pipe installation height (inlet pipe horizontal section from the bottom level), inlet pipe diameter, opening size, number, distance and direction of inlet pipe horizontal section, can determine the optimal design parameters of inlet pipe;(5) Using orthogonal experimental design method can clearly know the factors and levels of "L" shaped inlet pipe. The influence of.design parameters on turbulent kinetic energy and volume fraction of water can be obtained with range analysis method to simulate25sets of experiments. By comprehensive balance analyzing, the influence of the various factors on the turbulent kinetic energy and volume fraction of water curves can be drawn. Then, the optimal design scheme for "L" shaped porous buffer inlet pipe is proposed. Because of this, simulated test is carried out; (6) According to the optimal design scheme, field application test has been taken on. It proves that numerical simulation is right and reliable. At the same time, the feasibility and advantages of the optimal design scheme can be showed.The results showed that "L" shaped porous buffer inlet pipe has some characteristics such as slowing down the out flow of oil from inlet pipe, reducing the degree of disturbance between the fluid particles and improving the quality of oil extraction. By using orthogonal experimental design method, the optimal design scheme for "L" shaped porous buffer inlet pipe can reduce turbulent kinetic energy to0.003154m2·s-2and it also can increase oil concentration to99.23%. Compared with the preliminary design scheme, the degree of turbulence is reduced by3.10%and the quality of oil is improved by0.04%.