Investigation of influence of wall temperature on particulate deposition using novel dynamic microscopic setup

Abstract

This study investigates the influence of the wall temperature on the wax particulate deposition mechanism, analyzing the average deposit thickness, the growth rate, and agglomerates of wax crystals using a state-of-the-art microscopic dynamic in-situ visualization technique. The higher the wall temperature, the lower the growth rate and the thinner the deposit thicknesses formed, showing good agreement with conventional flow-loop observations. Similarly, the higher the wall temperature, the smaller the agglomerates formed in laminar cases. Furthermore, the wall temperature has a more significant influence in the laminar case than turbulent. A reduction of 69.3% on the final average deposit thickness measurements was obtained under the laminar flow regime for an increase of 1.9 °C in the wall temperature, while for turbulent flow regimes, the maximum reduction in average deposit thickness was observed to be no higher than 44.4%, even though the wall temperature was varied 3.2 °C. CFD simulations were conducted to determine the radial temperature profile of the oil, showing that the higher the flow rate becomes, the less variation is observed in the radial temperature. The simulated temperature boundary layer thickness for laminar cases was approximately equal to 4.16 mm, while for the turbulent case it is approximately 2.86 mm.