Exergy analysis of DSG parabolic trough collectors for the optimal integration with a combined cycle

A comprehensive energy and exergy analysis was conducted for various components of a direct steam generation (DSG) parabolic trough solar collector field under nominal operating conditions to assess performance of the components and to optimally integrate them with a thermal system. The solar field was modelled mathematically to compute thermal loss and consequently the thermodynamic efficiencies. To minimise inefficiencies in the solar field and to integrate it optimally with a reference combined cycle, the solar field was coupled to the bottoming cycle of the power plant. The solar energy was exploited in this conceptual integrated solar combined cycle (ISCC) to preheat the condensate water and to evaporate the water from economiser up to the prescribed quality of 0.8 in a once-through DSG system. This ISCC was further investigated for optimal design variables including inlet temperature of the water to the solar field and bleed pressure of the steam to deaerator.