Integration of Accurate Thermo-Mechanical Receiver Models into Concentrated Solar Power System Design

Abstract

Concentrated Solar Power (CSP) systems emerge as promising technologies for providing reliable and renewable energy. Yet, the overarching challenge lies in advancing CSP technologies to enhance efficiency and sustainability while ensuring economic viability, emphasising the importance of comprehensive techno-economic assessments. This dissertation presents an integrated system modelling methodology for assessing the techno-economic performance of CSP systems. It addresses the critical role of the receiver in CSP plant efficiency and reliability, emphasising the need to ensure structural integrity to prevent early failure and production losses.

A novel aspect of this research is the development of a comprehensive system-level model for a third-generation sodium/salt CSP system, which operates with a supercritical CO2 power block at an inlet temperature of 700 C. This model incorporates dynamic and steady-state components from the SolarTherm library to enhance off-design performance estimation, facilitating annual performance simulations and techno-economic assessments via Levelised Cost of Energy (LCOE) estimations.

The research introduces a techno-economic assessment of a novel "numbering-up" approach for this CSP system, comparing four configurations (1X100, 2X50, 3X33, and 4X25 MWe) to determine the most cost-effective design. A significant finding is that a single 1x100 MWe CSP tower system achieves the lowest LCOE, highlighting the trade-offs between cost, reliability, and scalability in CSP system design.

Further, the thesis presents a fully integrated dynamic multi-year thermo\hyp{}mechanical model for estimating receiver damage, a critical factor in ensuring the longevity of the CSP system. This model combines incident flux maps and operating conditions with detailed thermal and structural analyses to accurately predict receiver stress and damage. Validation against experimental data and other literature, including the Gemasolar receiver case, confirms the reliability of the model.

A key contribution of this research is the calculation of improved Allowable Flux Densities (AFD) in molten salt receivers based on detailed thermo\hyp{}mechanical analysis. This significantly extends receiver life and reduces operational costs with minimal impact on energy production. This novel approach results in receiver durability improvements and a substantially lower LCOE, marking a significant advance in CSP technology by addressing the limitations of previous models and enhancing system longevity and cost-effectiveness.

In summary, this dissertation offers novel insights and methodologies for designing and optimising CSP systems, contributing to the advancement of solar energy technology and its economic viability. A detailed techno-economic and thermo-mechanical analysis presents strategies for improving CSP system design, efficiency, and reliability, supporting the development of commercial-scale systems within the US DOE Gen3 Liquid Pathway project. Show more