Field Test of Water-Steam Separators for Direct Steam Generation in Parabolic Troughs

Abstract

Direct steam generation (DSG) represents a promising option to improve today’s parabolic trough technology for solar thermal power generation. The European DISS and INDITEP projects have proven the feasibility of the DSG process under real solar conditions at the DISS test facility at the Plataforma Solar de Almería (PSA) (Zarza, E., Valenzuela, L., Léon, J., Hennecke, K., Eck, M., Weyers, H.-D., Eickhoff, M., 2004, “Direct Steam Generation in Parabolic Troughs Final Results and Conslusions of the DISS Project,” Energy, 29, pp. 635–644). These projects have also shown that the recirculation mode is the preferred operation mode for DSG collector fields. This concept requires water-steam separators at the end of the evaporation section of the collector loop. Both compact water-steam separators for every single row or huge separation drums for the whole collector field are considered. Small compact water-steam separators show a lower inertia, reducing the time for start-up. Within INDITEP and the German R&D project SOLDI compact water-steam separators have been developed, manufactured, and tested by DLR and Siemens, with its subcontractor Framatome ANP. Prototypes of a cyclone and a baffle separator have been implemented into the DISS test facility. More than 200 tests have been performed to investigate the separation efficiency, the pressure loss, and the performance under transient conditions. This paper focuses on the steady-state tests.