International Energy Agency/Small Solar Power Systems Project: The IEA, SSPS High Flux Experiment : Testing the Advanced Sodium Receiver at Heat Fluxes up to 2.5 MW/m2

Results and conclusions of the Iea-Ssps High Experiment are presented together with the thermodynamic theory of the Advanced Sodium Receiver. During the experiment, flux distributions, surface temperature distributions, efficiencies and losses, were measured and calculated in a power range of 0.8-3.5 Mw at different sodium inlet/outlet temperatures. The design heat flux of 1.4 Mw/m2 was increased to 2.5 Mw/m2 resulting in a slightly increased total receiver efficiency of over 90%.

1. High Flux Experiment Test Program.- 1.1 The Advanced Sodium Receiver at SSPS-CRS.- 1.2 Heliostat fields available at IEA-SSPS.- 1.3 Achievable High Flux Operating Conditions.- 1.4 The Test matrix for the High Flux Experiment.- 1.5 The High Flux Experiment Test Program.- 1.6 Participants and Work Packages.- 1.7 References.- 2. Asr Thermal and Stress Analysis for 2.5 Mw/M2 Peak Flux.- 2.1 Introduction.- 2.2 Thermal Analysis.- 2.2.1 Incident heat flux map.- 2.2.2 Receiver performance at different inlet/outlet conditions.- 2.2.3 Detailed thermal analysis results for case A3.- 2.2.4 HFD and FAS bar passes shading effect.- 2.3 Evaluation of ASR residual lifetime before High Flux Testing.- 2.3.1 ASR spent life evaluation before starting the HFE.- 2.3.2 ASR residual lifetime.- 2.4 Stress Analysis.- 2.4.1 New operating conditions to be considered in the lifetime analysis.- 2.4.2 ASR critical points for stress analysis.- 2.4.3 Most irradiated tube panel stress analysis.- 2.4.4 Triplet stress analysis.- 2.4.5 Lifetime evaluation.- 2.5 Conclusions.- 2.6 References.- 3. Metallographic Analysis of the Asr Receiver Tubes.- 3.1 Introduction.- 3.2 Results of investigation.- 3.2.1 Visual assessment of the tube wall.- 3.2.2 Positions of the test points on the tube wall.- 3.2.3 Performance of the nondestructive structural inspection and findings.- 3.3 Assessment of the investigation findings.- 4. Asr Tube Deformation Measurements.- 4.1 Introduction.- 4.2 Method of Measurement.- 4.3 Results.- 4.4 Conclusions.- 5. Asr Absorptance Measurements.- 5.1 Introduction.- 5.2 Instrument characteristics.- 5.3 Methods for estimating absorptance distribution.- 5.3.1 Absorptivity Distribution Calculation.- 5.3.2 Method for determination of homogeneous absorptivity zones.- 5.4 Results.- 5.5 Conclusion.- 6. Heliostat Selection for Certain Peak/Power Levels.- 6.1 Introduction.- 6.2 Input Data.- 6.3 Output Data.- 6.4 Results.- 6.5 References.- 7. Determination of Feasible Peak and Power Levels.- 7.1 Introduction.- 7.2 Prediction of Irradiance.- 7.2.1 First Method.- 7.2.2 Second Method.- 7.2.3 Results.- 7.3 Determination of the feasible peak/power levels.- 7.3.1 Parameters which affect the feasible power-peak region.- 7.3.1.1 Irradiance.- 7.3.1.2 Sun elevation.- 7.3.1.3 Heliostat aiming strategy.- 7.3.1.4 Heliostat availability.- 7.3.1.5 Reflectivity of the heliostat mirrors.- 7.4 Conclusions.- 7.5 References.- 8. Evaluation and Qualification of the HFD Bar.- 8.1 Introduction.- 8.2 Description of the HFD Measurement System.- 8.3 Repeatability of the HFD Bar Measurements.- 8.4 Comparison of HFD bar measurements and HELIOS calculations.- 8.5 Conversion to the ASR Plane.- 8.6 Conclusions.- 8.7 References.- 9. Receiver Thermodynamics Under High Flux Conditions.- 9.1 Introduction.- 9.2 Numerical simulation.- 9.3 Comparison Calculation-Measurement.- 9.4 High Flux Experiment.- 9.5 Conclusions.- 9.6 References.- 10. ASR Simulation with the ‘Theresa’ Code.- 10.1 Introduction.- 10.2 Modifications of THERESA.- 10.3 Results.- 10.4 Conclusions.- 11. ASR Surface Temperature Measurements.- 11.1 Introduction.- 11.2 Measurement method and hardware.- 11.2.1 Picture Processing.- 11.2.1.1 Calibration of infrared pictures with panel inlet temperatures.- 11.2.1.2 Correction of the geometrical distortions.- 11.2.2 Estimation of error for the infrared imaging system.- 11.2.3 Estimation of emissivity.- 11.2.4 Average surface temperature, emission and convection losses.- 11.3 Presentation and Discussion of the Results.- 11.3.1 Measurement days and tests performed.- 11.3.2 Collected raw data for the evaluation of the infrared data.- 11.3.3 Measured temperature distributions.- 11.4 Conclusions.- 11.5 References:.- 12. Advanced Sodium Receiver Losses.- 12.1 Introduction.- 12.2 Optical losses.- 12.3 Thermal Losses.- 12.3.1 Description of the experiments.- 12.3.1.1 Normal flow operation.- 12.3.1.2 Reverse flow operation.- 12.3.2 Total losses.- 12.3.3 Radiative losses.- 12.3.4 Conductive losses.- 12.3.5 Convective Losses.- 12.3.6 Convective Coefficient.- 12.4 Procedure for calculating the losses during normal operation.- 12.5 References.- 13. ASR Loss Tests by Complementary Heliostat Field Configurations.- 13.1 Evaluation Method.- 13.2 External Receiver Thermal Loss.- 13.3 Part-Load Performance.- 13.3.1 Thermal Loss Predictions.- 13.4 Thermal Loss Predictions (Receiver Math Model).- 13.5 Conclusions.- 13.6 References.- 14. Receiver Efficiency Evaluation Based on Recorded Das Data and Helios Calculations.- 14.1 Introduction.- 14.2 Methods.- 14.2.1 Definition of Steady State.- 14.2.2 Calculation Methods.- 14.3 Results.- 14.4 Power Distribution.- 14.4.1 Receiver Efficiency.- 14.4.2 Panel efficiencies.- 14.5 Conclusions.- 14.6 References.- 15. ASR High Flux Experiment Results and Conclusions.- 15.1 Introduction.- 15.2 Major achievements.- 15.3 Results.- 15.3.1 Thermomechanic Evaluation.- 15.3.2 Thermodynamic Evaluation.- 15.3.2.1 Incident Flux Distributions.- 15.3.2.2 Temperature Distributions.- 15.3.2.3 Thermal Losses.- 15.3.2.4 ASR Efficiencies.- 15.4 Conclusions.- 15.5 References.- Appendix A. Tables of Infrared Measurements.- Appendix B. List of Illustrations.- Appendix C. List of Tables.