Experimental and theoretical studies on the mixing pressure and prediction model of the steam-water two-phase injector

The steam-water two-phase injector is widely used in various industrial applications. However, the use of improper local parameters frequently results in inaccurate predictions of the injector performance. Among them, the mixing pressure plays a crucial role in predicting the injector performance. In this paper, experimental and theoretical studies were carried out on the mixing process and overall performance of the steam-water two-phase injector. The mixing pressure is found to locate at the end of mixing chamber, where the pressure difference between wall and center is equal to 0. The experimental results indicate that the mixing pressure increases with the steam outlet pressure (related to the steam inlet pressure) and the temperature difference between inlet steam and inlet water, but changes very slightly with the inlet water pressure. Then a semi-theoretical model for calculating the mixing pressure was obtained, and the predict accuracy of mixing pressure was within +25%. A one-dimensional injector model was developed based on newly developed mixing pressure model, which could predict the axis pressure distribution and the pressure-raising performance, with prediction accuracy better than +15%.