Performance evaluation of natural draft dry cooling towers and pre-cooled natural draft dry cooling towers in concentrated solar power plants

This study examines the integration of Natural Draft Dry Cooling Towers (NDDCT) and pre-cooled NDDCT as innovative heat rejection systems for a 50 MW Concentrated Solar Power (CSP) plant, comparing their performance against conventional alternatives: Mechanical Draft Wet Cooling Towers (MDWCT), Air-Cooled Condensers (ACC), and hybrid pre-cooled ACC systems (media pads and spray nozzles). Analytical models for the cooling systems and their interaction with the CSP plant were developed and validated against results reported in the literature. Using hourly temporal resolution and real climatic data from Granada, Spain, the analysis evaluates the annual impact of these systems on energy generation and water consumption. The results demonstrate that pre-cooled NDDCT increases annual power generation by approximately 1400 MWh compared to NDDCT, with substantial performance improvements during peak summer conditions. Although MDWCT achieves the highest efficiency, it comes at the cost of significant water consumption. Pre-cooled NDDCT stands out as a promising hybrid solution, balancing improved condensation performance (only 2.9% less efficiency compared to MDWCT) with minimal water usage (76.7% less than MDWCT). This study provides valuable insights for optimising CSP plant performance in arid regions, advancing beyond previous efforts in the literature.