Field Test of Water-Steam Separators for the DSG Process

Abstract

The direct steam generation (DSG) in parabolic trough collectors is a promising option for improving of the mature SEGS type parabolic trough solar thermal power plant technology. The European DISS and INDITEP projects have proven the feasibility of the DSG process in parabolic trough collectors under real solar conditions at the life size DISS test facility at the Plataforma Solar de Almería (PSA). These projects have also shown that the recirculation mode is the preferred operation mode for DSG collector fields for near term applications. The water-steam separator is a key component of collector fields operated in recirculation mode. Either small compact water-steam separators for every single row or huge separation drums for the whole collector field are conceivable. Small compact water-steam separators offer the advantage of a lower inertia thus reducing the time for start-up and lower investment. Within INDITEP DLR and Siemens, with its subcontractor Framatome ANP, have developed, manufactured and tested compact water-steam separators. Framatome has investigated cyclone separators, whereas DLR has focussed on baffle separators. Prototypes of both separator concepts have been implemented into the DISS test facility at the Plataforma Solar de Almería for testing under real DSG conditions. More than 200 tests have been performed to investigate the separation efficiency, the pressure loss and their performance under transient conditions. A main conclusion from this test campaign is that compact water steam-separators are available for near term applications. Detailed results of the test campaign and basic guidelines for their operation are presented in the paper.