Direct Steam Generation for Concentrated Solar Technologies – SteamSun

The SteamSun project explores Direct Steam Generation (DSG) in Concentrated Solar Technologies (CST) to decarbonize the energy mix and various industrial processes. It aims to experimentally characterize and model water-steam boiling flows in large-diameter horizontal pipes, typical of solar receivers. The objective is to better understand flow regimes to optimize steam and electricity production while controlling thermomechanical stresses on the receiver. Scientifically, we will focus on characterizing, understand and model the coupled flows involved in this process.
The project relies on the ConBo experimental facility, developed at the PROMES laboratory, which replicates convective boiling conditions in large-diameter tubes (50 mm). Using advanced instrumentation, including a Wiremesh sensor, it will be possible to map different flow regimes (stratified, intermittent, annular, etc.) and their associated thermal performances. The impact of parameters such as mass flow rate, thermal power, and receiver inclination will also be studied.
The project's numerical modeling approach is based on coupled thermohydraulic and thermomechanical simulations, using Neptune_CFD and Syrthes, software developed for the nuclear industry. Simulations will validate these tools for low-pressure horizontal configurations and analyze the mechanical stresses experienced by the receivers.
Finally, SteamSun aims to provide a database and predictive models to optimize DSG solar receivers and maximize their lifespan. These results will also be applicable to other industrial processes involving boiling flows, such as food processing or steam production for specific applications.