Abstract: To analyze the capillary effect on the liquid vapor separation in liquid vapor separation condenser, a mathematical model has been established. The effects of static pressure, gravitational force, capillary pressure and shear stress  were included in the model, and the effects of different orifice diameter, number, their combination, inlet quality and flow rate were researched. The results show that orifice diameter and orifice number have similar effects on performance. The liquid film height decreases while the diameter or number increases. The film height disappears when the diameter is 1.3 mm and the number is 8. But inlet flow rate and quality have opposite effects. The film height disappears when the quality is 0.5 and flow rate is 0.058 kg/s.

Key words: liquid vapor separation; orifice diameter; orifice number; quality; flow rate; capillary effect