Abstract: The heat transfer coefficient and thickness of the atomized liquid film are important factors in determining the spray cooling effect. The numerical simulation method is used to analyze the effect of spray pressure, height and tilt angle on the heat transfer characteristics of spray cooling based on three angles of liquid film thickness, heat transfer coefficient and temperature distribution on the heating wall. The results show that the spray pressure is an important factor affecting the heat transfer effect. Compared with the low pressure working condition, the liquid film formed on the wall surface is small in the high pressure working condition, the average wall temperature is low, and the heat exchange capacity is strong. The greater the pressure condition, the higher the wall temperature drop. Mainly because the injection pressure is increased, the movement speed of the liquid film is increased, resulting in a strong disturbance between the air and the air, which promotes liquid film breakage and droplet formation. The height is changed so that the density of the droplets ejected to the wall is different, resulting in uneven temperature distribution. The study also found that there is an optimal value of the effect of spray height on heat transfer. When H=6mm, the heat transfer effect is best. Similarly, changing the angle of inclination causes the wall to be divided into a spray-intensive area and a sparse area, and the heat exchange effect is largely different. When the spray angle θ=30°, the heat transfer effect of the wall surface is best and the temperature distribution is relatively uniform. The variation rule obtained by the analysis provides a theoretical basis for the setting of the spray parameters and the optimization of the spray effect.

Key words: computational fluid dynamics(CFD), heat transfer, heat transfer coefficient, liquid film thickness, numerical simulation