Optimization of Heat Exchanger Design for Third Generation Centralized Solar Power Generation System: CFD and Thermoeconomic Coupling Method for Improving Thermal Performance and Reducing Storage Costs of Batteries

Third-generation centralized solar power (CSP) systems require advanced thermal management strategies to enhance heat transfer efficiency and reduce the overall cost of thermal energy storage and battery integration. This study develops a comprehensive computational fluid dynamics (CFD) and thermoeconomic coupling model to optimize the design and operating parameters of a high-performance heat exchanger integrated within a Gen3 CSP system. The model evaluates the influence of key structural and operational parameters—including channel geometry (hydraulic diameter 2–8 mm), flow rate (0.2–1.5 kg/s), inlet temperature (450–750 K), and heat transfer surface enhancement factors—on entropy generation, heat transfer coefficient distribution, pressure drop, and overall system exergy efficiency. Results indicate that optimized channel configurations reduce total entropy generation by 14–21% while enhancing the average heat transfer coefficient by 18–26% compared to baseline designs. Increasing flow rate improves thermal uniformity but raises pumping power consumption by up to 32%, highlighting the trade-off between thermal performance and auxiliary energy demand. Thermoeconomic analysis reveals that the optimized design lowers levelized storage costs by approximately 11–17% through improved thermal utilization and reduced battery cycling losses. The integrated CFD–thermoeconomic framework identifies an optimal configuration that maximizes exergy efficiency (up to 88.4%) while minimizing total annualized cost. The findings provide quantitative design guidelines for enhancing thermal performance and economic viability of next-generation centralized solar power systems coupled with advanced energy storage technologies.