Sensitivity analysis of heat dissipation factors in a hot oil pipeline based on orthogonal experiments

Abstract

The study of phase-change heat-transfer characteristics of crude oil has been one of the hot issues in the field of gathering and transportation. The process of phase-change heat transfer of crude oil involves many complicated problems such as natural convection treatment, latent heat treatment, phase-change interface determination and fluid characteristic change. A mathematical model based on the additional capacity heat method is proposed in this article, and the momentum equations of crude oil liquid phase are presented for Newtonian and non-Newtonian fluids. The aim of this study was to investigate the influence of different factors on the heat transfer performance during the shutdown process of an overhead pipe. Experiments were conducted to verify the model and the solution method; the experimental and model results showed good agreement with a maximum relative error of 4.57%. The temperature fields and solidification conditions of crude oil in pipelines under different shutdown conditions were determined, and the sensitivity of the main effect factors was determined through an orthogonal experiment. The results show that the order of influence was oil initial temperature >thickness of insulating layer >air temperature >thickness of wax layer. The results of the study have important guiding significance on the control of shutdown time and the determination of restarting schemes.

The affection of Crude Oil Physical Parameters on Heat Transfer

“…Shutdown pipeline temperature field numerical simulation results is necessary for confirming the safe shutdown time, making restart up scheme and maintenance plan. Liu Yang [8], Xu Ying [9][10], established a new zoning model and analyzed the affection of physical properties of the crude oil and different external factors on the total setting time. diameter of insulating layer, respectively.…”

Calculation of Soil Natural Temperature Field in Cold Region and Analysis of Influencing Factors

“…Xu [6][7] considered the influence of atmospheric annual cycle temperature change on soil temperature field and, on this basis, analyzed the influence of pipeline buried depth and soil thermal conductivity on the temperature field of crude oil in the shutdown pipeline.Fan [8] applied the mathematical model of heat and mass transfer in porous media to compare the daily temperature changes in a cylindrical soil bed with a height of 500mm and a radius of 250mm in summer and winter when the environmental wind speed was 4m/s and 1m/s respectively and the environmental relative humidity was 35% and 85% respectively.B Han [9]analyzed the difference of soil temperature before and after precipitation in Gobi region .…”