In batch transportation of finished oil products, mixed oil would be produced by adjacent batch oil. The cases of 30°, 45°,60° or 90° for the joint line of the variable diameter part and the straight pipe of the variable diameter pipe were calculated by the CFD software. The conclusion show the relationship and the change law between the angle of the joint of the variable diameter part and the length were researched. The results show that with the angle increased, the mixed oil segment length decreased in the sudden expansion pipe and the opposite conclusion in the reducer, which was coincided with engineering basic phenomenon.

Factors that affect pipeline safety and reliability are numerous and randomness, so directly solving the limit state equation is difficult. The solving process of using RF method is simple and high precision. Based on reliability theory and B31G-1991 standard, comprehensively considering the randomness of the corrosion defect length, radial depth of defect, the corrosion rate, wall thickness, pipe yield strength and pressure pipelines, using RF method established a mathematical model for the reliability analysis of corrosion piping. The computer program for this method was developed. The results show that reliability index of the pipe decreased with the increase of defect length, defect depth, and the radial in corrosion rate and that the defect depth is the main factor of pipeline failure. The pipeline reliability index with the pipe yield strength increases in a linear increased, and rapidly reduces with inside pressure increasing.

 

 

For the problem of oil leak in different soil particle diameter, using CFD simulation software to establish the soil porous media mid-stream solid coupled mathematical model of phase transitions. The simulation results show that before the leaking, the distribution of isotherms of the steady-state temperature field becomes the sharp of flat circle and the temperature lower from inside to outside. Meanwhile, this distribution does not have obvious changes in the different sizes of soil particles; after the leaking, the isothermal lines in the small particle diameter soil presented divergent patterns with reduction of the distribution from inside to outside. At the same time, with the leakage of oil flowing into the porous medium, the temperature gradient tended to be stable. In large particles soil, because of the low power of oil flow resistance, the change of water which exit in permafrost could happen faster, and the stochastic distribution of the isotherms of the divergent is more obvious. This situation destructed the stable temperature field more seriously.

A system dynamics model of water resources utilization in urban ecosystem was established. The relationships among water resources utilization, urban economic development, and pollutant emissions, etc in urban ecosystem-were analyzed. Taking Fushun for instance, four water resources utilization patterns in urban ecosystem were designed, and then the trends of water resources utilization in urban ecosystem were forecasted and analyzed during 2011-2020. The results show that the water resources system in urban ecosystem consisted of four subsystems, namely, water resources subsystem, population subsystem, economy subsystems and environment subsystem. The comprehensive development pattern can improve the utilization of water resources in Fushun city among the four, and in that case, the water resources factor, total population, the GDP of secondary industry, COD discharging will reach 1.042 2, 2.16 million, 123.46 billion Yuan, and 31 308 t, respectively.

A 3D CFD model was established. The oil diffusion of lower leakage of the pipe in the soil porosity of 0.45 and 0.47 was simulated and analyzed. The results show that the oil spread to the surrounding area to expand in a way of oval in compact soil. The area, width and depth of spread increase largely in the initial of the leakage. After diffusion several minutes, they are increasing stably over time and the volume of diffusion is in smaller growth rate as the time changed. The oil spread downward expansion over narrow width of the diffusion region in loose soil. Spread width and area growth trends are slow down after. The depth of spread increased larger than former soil and the volume of diffusion were in larger growth rate as the time changed.

In the process of transportation for clean oil, tank truck transportation account for a large portion, but air-resister occurs easily in the process of unloading, this will lead to some clean oil left in the tank. Through drawing the geometrical model of the tank truck, set up the temperature field mathematical model and boundary conditions, and made use of CFD software to solve the problem, the spread of temperature field was acquired. Combining the conditions that lead to air-resister, the best time for unloading clean oil was received. The field practice indicates that the time interval for unloading can conduct actual production exercises and improve work efficiency.