NUMERICAL STUDY ON THE EFFECT OF THERMAL DIFFUSIVITY RATIO IN PHASE CHANGE HEAT TRANSFER OF CRUDE-OIL USING LATTICE BOLTZMANN METHOD

When the long distance crude-oil pipe-line is stopped, the crude-oil will solidify gradually with the decrease of the temperature in the pipe-line. The solid-liquid thermal diffusivity can reflect the ability of heat diffusion in the phase change heat transfer process of crude-oil stop-transport. Based on the mathematical model of oil phase transition heat transfer established by enthalpy method, the lattice Boltzmann method is used to solve the governing equations of oil phase transition heat transfer. According to the simulation results, the phase change heat transfer process of crude-oil is divided into three-stages, and the mechanism of the phase change heat transfer process of crude-oil is studied. The results show that the in-fluence of solid-liquid thermal diffusion ratio increase gradually with time. When Fourier number & GE;0.043, Nusselt number and convective heat transfer intensity of mobile phase interface slightly decrease with the increase of solid-liquid thermal diffusivity ratio. The research results of this paper can provide a reference for con-trolling the stoppage time of pipe-line.