Direct steam generation (DSG) in parabolic troughs was first studied in the early 1980s by Murphy (1982) and Pederson (1982). Intensive research on DSG then started in 1988, when Luz identified this technology as the desired system for a future generation of its power plants. These R&D activities were not terminated on Luz’s demise in 1991, but have been continued by several institutes and companies in Europe as well as in Israel (Dagan et al., 1991, Mu¨ller et al., 1992a, b, 1993, 1994). This paper concerns the dynamic reaction of the water-steam flow. In order to investigate this, a numerical simulation program was developed at the ZSW. The numerical approach, its verification, and results of an extended study concerning the reaction and the control (ability) of a once-through DSG system at different weather conditions are presented.

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