Temperature Drop Characteristics of Crude Oils After Shutdown of a Pipeline for a Batchwise Transportation System

Abstract

In recent years, it has been proposed to transport different crude oils in a batchwise operation in a pipeline. In this article, thermal models of the normal operation and shutdown processes are established and advanced numerical methods are employed. Thermal characteristics during normal operation and shutdown are analyzed in detail through numerical simulation. Shutdown occasion parameters are defined to describe the unique shutdown state during a batch. Conclusions can be drawn that the temperature distribution in a batchwise operation is greatly different from that of an ordinary hot oil pipeline. The temperature drop during the shutdown process is determined by shutdown occasion parameters and shutdown duration. Even if there is the same crude oil in the pipeline, the temperature distributions at different occasions have significant differences. When the front of high-pour-point (HPP) oil attains the pipeline outlet, the shutdown hazard is the greatest, with the longest HPP oil segment in the pipeline and the fastest temperature drop rate during shutdown. The results not only provide a reference for the real operation of the pipeline, but also lay a foundation for further study of the restart process of the pipeline in batchwise transportation.