Optimization of solar field layout and flow velocity in a solar-aided power generation system

The solar-aided power generation (SAPG) system is an efficient way to integrate solar thermal energy into the normal coal-fired power plant. This work constructed a hydraulic model of a parabolic trough solar field and updated its thermodynamic evaluation algorithm. Moreover, this work aimed to optimize the solar field layout and flow velocity of heat transfer fluid (HTF) in view of net solar-to-electricity efficiency, which deducted pump power consumption from the solar-generated electricity. Furthermore, the non-uniformity of the outlet HTF temperature in each loop was found on the basis of the proposed model. This non-uniformity threatened the safety of the solar field. The number of loops should be reduced, and the flow velocity of HTF should increase to alleviate such non-uniformity. The case study based on a typical 330 MW SAPG system indicated that the optimal solar field layout consisted of 24 loops with eight solar collector assemblies in each loop. The optimal average flow velocity of HTF was 2.33 m/s. The corresponding net solar-to-electricity efficiency was 22.83%, and the net solar-generated electricity was 8.4984 MW. •Hydraulic model was designed to investigate the non-uniformity of loop flow rate.•The pump power consumption was considered in the system performance evaluation.•Reducing loop number or increasing flow rate alleviates the non-uniformity.•Layout and flow velocity of solar field were optimized.