Procedure to determine the temperature variation of heavy oil with pseudoplastic behavior in conductive pipes

Abstract

In industrial pumping systems, non-stationary flow is common. Because these facilities usually operate at a temperature higher than the surroundings, this causes a variation in the density and viscosity of the fluid over time. In the case of non-Newtonian fluids with pseudoplastic behavior, the process is affected by the lack of adequate and specific procedures to determine the thermo-physical properties of the fluid. This article proposes a calculation procedure to determine the temperature variations of heavy oil under heat exchange conditions in insulated pipes, consisting of 24 equations. The proposed equations have been validated for real cases in industrial systems, for which the estimated temperature variation value could be predicted with a maximum error of 1.83% and an average value of 1.39%. The simulation results indicate that temperature losses in pipes increase with increasing flow rate and decreasing pipe diameter and that these losses reach a maximum value of 0.58 ºC for a smaller diameter pipe (0.2 m) and lower volumetric flow rate (54,361 m³/h).