Leak rates of high pressure steam-water across simulation crack

This paper presents a critical leak flow from a simulated crack under the fluid condition of high-pressure water-steam and supercritical water. An experimental study of critical leak flow has been performed at Xi'an Jiao tong University (XJTU) with a rhomboid crack and two narrow circular cracks, which could be applied in the leak-before-break (LBB) analysis. A rhomboid crack with an opening displacement of 140 μm and two circle cracks with diameters of 1 mm and 1.84 mm were performed in the experiments. Pressure drop and flow rates were measured to analyze the flow characteristics. Experimental parameters covered pressures up to 23 MPa and temperatures up to 400 °C. The results were compared with the theory of Henry's non-equilibrium subcooled two-phase critical flow in long tubes. It was found that the Henry's Homogeneous Non-Equilibrium Model (HHNM) could be extended to predict supercritical fluid critical flow when temperature is lower than the pseudocritical point. A modified 1-D adiabatic friction-choked flow model was developed to upstream superheated steam and supercritical water when temperature is higher than the pseudocritical point. It was found that the predictions of the modified 1-D adiabatic friction-choked flow model agreed well with the present experimental data.