Local measurements in the flow of a steam injector and visualisation

A steam injector is a thermocompression device where the steam drags direct ly a subcooled liquid and delivers a liquid with an outlet pressure higher than both upstream fluid pressures. The functioning principle of injectors involves sophisticated thermohydraulic processes whose present knowledge is essentially empirical. This work presents an experimental approach of stea m injector in order to finely understand and quantify the physical laws dri ving the flow in the mixing chamber. Local measurements (2D) are carried ou t on a special device with a rectangular section, where the flow was visual ised. These measurements are the void fraction, the static pressure and the static temperature. They permit the calculation of all the variables and a well understanding of the physical phenomena involved in the flow. Especia lly, we show, in some well-defined zones, the existence of important non-eq uilibrium kinetic, thermal and thermodynamic phenomena. (C) 2000 Editions s cientifiques et medicales Elsevier SAS.