Development of Receivers for the DSG Process

The direct steam generation (DSG) in parabolic trough collectors is a promising option for improving 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). Because of this successful demonstration the erection of the first DSG demonstration plant is expected for the near future. So far no commercial parabolic trough receivers, also known as heat collecting elements (HCE), are available for the DSG process. These receivers would have to withstand a higher operation pressure since the operation pressure of the receivers is equal to the life steam pressure of the power cycle which can be 100 bar and more. Furthermore the thermal load of the receivers is higher since the heat transfer in the superheating section of a DSG collector loop is worse than that of SEGS type collector loops. To solve this problem SCHOTT Rohrglas has decided to adapt their receivers to the specific needs of the DSG process. In collaboration with the German Aerospace Center (DLR) necessary modifications were identified and integrated into the design of the SCHOTT receiver. Prototypes of the receivers have been manufactured. The paper presents the design of the DSG receivers for the first time