Experimental and numerical research on the effect of the inlet steam superheat degree on the spontaneous condensation in the IWSEP nozzle

Abstract The spontaneous condensation process takes place in many power engineering machines and devices, such as steam turbines, supersonic separators, ejectors etc. In the paper, the effect of the inlet steam superheat degree in steam condensing flow through the IWSEP (International Wet Steam Experimental Project) nozzle was investigated experimentally and numerically. The experiment was conducted for the low inlet pressure values under different inlet superheat conditions. The static pressure on the nozzle walls as well as the liquid phase properties in the three positions along the nozzle centreline were measured. The paper delivers new experimental data desirable for validation of the numerical models. For the numerical simulations, a condensation model using the Benson surface tension model was employed, and its accuracy was checked by comparing with the experimental data of SUT. The results state clearly that the condensation model using the Benson surface tension model can predict the spontaneous condensation process accurately, and the error is less than 5%. With the inlet steam superheat degree increasing, the condensation process moves downstream and the condensation strength weakens, and the nucleation zone range increases about 36mm. The presented results provide a good reference for further research in the field of condensing steam flows and for the improvement of both experimental and numerical methods and models.