Analysis of the Mass Flow Effect on the Thermo-Hydraulic Behavior of the Direct Steam Generation in Parabolic Trough Solar Collectors

Among the most attractive alternatives to parabolic trough solar power plants (PTC) is direct steam generation (DSG). The environmental problems related to the use of thermal oil can be minimized, as well as the investment and maintenance charges. However, the instability of the fluid flows generated in the solar field and the difficulty in controlling the process make this new technology still challenging. The receiver tubes can be damaged due to high-temperature gradients. For this purpose, it is necessary to examine the working conditions of the DSG-PTCs system. The water feed mass flow rate is the most important parameter that strongly influences the flow pattern and the process operating. Therefore, the present work focuses on the investigation of the feed mass flow rate impact on the steam production process in a row of PTCs. The outcomes of the numerical simulation indicate that, in order to prevent the stratification phenomenon, it is desirable to select a feed water flow rate more than 0.5 kg/s and to regulate it in accordance with solar flux to ensure a relatively high steam quality production.