Sandia capabilities for the measurement, characterization, and analysis of heliostats for CSP.

The Concentrating Solar Technologies Organization at Sandia National Laboratories has a long history of performing important research, development, and testing that has enabled the Concentrating Solar Power Industry to deploy full-scale power plants. Sandia continues to pursue innovative CSP concepts with the goal of reducing the cost of CSP while improving efficiency and performance. In this pursuit, Sandia has developed many tools for the analysis of CSP performance. The following capabilities document highlights Sandia's extensive experience in the design, construction, and utilization of large-scale testing facilities for CSP and the tools that Sandia has created for the full characterization of heliostats. Sandia has extensive experience in using these tools to evaluate the performance of novel heliostat designs

COUPLED OPTICAL-THERMAL-FLUID MODELING OF A DIRECTLY HEATED TUBULAR SOLAR RECEIVER FOR SUPERCRITICAL CO2 BRAYTON CYCLE

Recent studies have evaluated closed-loop supercritical carbon dioxide (s-CO2) Brayton cycles to be a higher energy density system in comparison to conventional superheated steam Rankine systems. At turbine inlet conditions of 923K and 25 MPa, high thermal efficiency (similar to 50%) can be achieved. Achieving these high efficiencies will make concentrating solar power (CSP) technologies a competitive alternative to current power generation methods. To incorporate a s-CO2 Brayton power cycle in a solar power tower system, the development of a solar receiver capable of providing an outlet temperature of 923 K (at 25 MPa) is necessary. The s-CO2 will need to increase in temperature by similar to 200 K as it passes through the solar receiver to satisfy the temperature requirements of a s-CO2 Brayton cycle with recuperation and recompression. In this study, an optical-thermal-fluid model was developed to design and evaluate a tubular receiver that will receive a heat input similar to 2 MWth from a heliostat field. The ray-tracing tool SolTrace was used to obtain the heat-flux distribution on the surfaces of the receiver. Computational fluid dynamics (CFD) modeling using the Discrete Ordinates (DO) radiation model was used to predict the temperature distribution and the resulting receiver efficiency. The effect of flow parameters, receiver geometry and radiation absorption by s-CO2 were studied. The receiver surface temperatures were found to be within the safe operational limit while exhibiting a receiver efficiency of similar to 85%

Sandia capabilities for the measurement, characterization, and analysis of heliostats for CSP.

The Concentrating Solar Technologies Organization at Sandia National Laboratories has a long history of performing important research, development, and testing that has enabled the Concentrating Solar Power Industry to deploy full-scale power plants. Sandia continues to pursue innovative CSP concepts with the goal of reducing the cost of CSP while improving efficiency and performance. In this pursuit, Sandia has developed many tools for the analysis of CSP performance. The following capabilities document highlights Sandia's extensive experience in the design, construction, and utilization of large-scale testing facilities for CSP and the tools that Sandia has created for the full characterization of heliostats. Sandia has extensive experience in using these tools to evaluate the performance of novel heliostat designs