A mathematical model was established, which is a three-dimensional and steady-state heat transfer and flow process mathematical model in top combustion stove. Then the temperature field and velocity field were obtained according to the model. Based on these, the temperature and velocity fields were discussed under the conditions of various air and gas inlet position. The results show that when the gas entrance in single-channel mode, the liquid's temperature and velocity distribution was uneven extremely and tilted toward the furnace wall of gas entrance side in the hot blast stove. On the other hand, when the air and gas entrance in interval mode, the liquid's temperature and velocity distribution is uniform, and this mode is beneficial to the top combustion stove to work steadily.

In the process of transportation for clean oil, tank truck transportation account for a large portion, but air-resister occurs easily in the process of unloading, this will lead to some clean oil left in the tank. Through drawing the geometrical model of the tank truck, set up the temperature field mathematical model and boundary conditions, and made use of CFD software to solve the problem, the spread of temperature field was acquired. Combining the conditions that lead to air-resister, the best time for unloading clean oil was received. The field practice indicates that the time interval for unloading can conduct actual production exercises and improve work efficiency.

When the gas-liquid two-phase flows through tee pipeline, the distribution of two phase in two branch pipes is always uneven. There may be only gas branch in pipelines when it is serious, while the other export tube may be full of liquid. The numerical simulation on oil-gas two phase fluxion in different time by CFD was made and the oil and gas separation characteristics in branch pipes were get. The results show that there will be gas-liquid separation phenomenon in branch pipe when the oil and gas flow through branch pipe of tee pipeline, and close to the mouth branch the separation phenomenon is obvious. There is almost no separation phenomenon in certain distance of the branch mouth.