Modeling and Sizing of a MW Solar DSG plant

Direct Steam Generation (DSG) Concentrated Solar technology, based on Linear Fresnel Reflectors (LFR) and aimed at supplying saturated steam to industrial processes, is a promising application; nevertheless, nowadays few case studies and very few installations have been developed. A methodology for the design optimization of a MW solar DSG plant is presented in this article and applied to a real case study of a Brazilian tire manufacturing facility. A steady-state model, with spatial discretization of the ordinary equations, allows characterizing the physical phenomena such as pressure drop and heat transfer, and therefore to determine the pressure and specific enthalpy trend along the recirculation loop. For each receiver tube of the solar collectors, the occurring single or two-phase flow pattern is calculated based on specific empirical equations developed for evaporation in horizontal tubes. Two reference operating conditions have been identified for the present case study, at which the optimal field layout results to be a series connection of all the collectors, and the optimal nominal flow rate to avoid possible harmful operating conditions for the absorber tubes is 1.0 kg/s.