| The operation of the long-distance complicated multi-product pipeline optimally, safety and efficiently is a difficult task the pipeline operating personnel faced. For that, it is necessary to grasp the transformation regulation of operating mode of the multi-product pipeline fully, in each link from the design to the operating management. The accurate mathematical model and the algorithm are required for developing the dynamic simulation software of pipeline. Based on theoretical analysis,numerical computation and dynamic simulation software to the batch transportation process has been developed.The oil quality parameters forecasting accurately is very important to research and analyze thoroughly the contamination characteristic and the hydraulic characteristic in contamination section. The prediction model of contamination viscosity has been established by using the formidable non-linearity mapping ability of artificial neural network. This model can predict contamination viscosity in each given point of the non-linearity influence factor. Its error is smaller than other way and it can completely meet the actual project need. As one-dimension contamination theory is difficult to explain the formation and development of contamination, and it also can't explain the contamination influence of the section velocity distribution, the two-dimension contamination theory is proposed, in which the convection play a dominate part. This equation is separated into pure convection equation and pure diffusion equation by using the time fission law. The pure convection equation is solved by using the method of characteristics and the pure diffusion equation is solved through using the time fission law again to convert the five pair angular into three pair angular. The method avoids numerical proliferation and the computation speed is also much more quickly.The new contamination mathematical model of batch transportation is established based on the Navier-Stokes equation, the mass transportation equation and the k ?εturbulent flow theory, and the numerical simulation of contamination in pipeline under special operating mode has been investigated with the help of PHOENICS. In the interface of two different oils, its result can reflect clearly the phenomenon of convection and mass diffusion. The influences of transportation order in the erect pipeline and shutdown and blind pipeline and right angle pipe to contamination are analyzed prominently.The traditional characteristic method which used to analysis hydraulic transient in batch transportation is improved. Thus, the new calculation formulas and corresponding boundary conditions are also brought forward. It can simulate hydraulic transient process in batch transportation and its result is reliable. The thermal transient equation, in which the temperature increment due to friction is taken into consideration, is derived on the bases of the continuity equation, momentum conservation equation and energy conservation equation. The thermal transient equation, in which the term with v 3 was involved, had been inferred, while the corresponding method of characteristics was constructed. By combining the thermal transient equation and the hydraulic transient equation and the contamination equation, the coupling thermal-hydraulic-contamination equations is offered. The corresponding characteristics method is also developed. Numerical experiment indicates the law has a higher accuracy.On the bases of the above studies, the dynamic simulation software using Visual Basic language is developed, which can simulate hydraulic transient and contamination process. This software is able to show every station's and the whole line's pressure value, temperature distribution, flow change as well as every contamination interface along with time, when hydraulic transient happened. It also can simulate the contamination process, including its change condition following time, the amount of contamination in final station etc.
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