Dostal V., Driscoll M.J., Hejzlar P. A Supercritical Carbon Dioxide Cycle for Next Generation Nuclear Reactors

MIT-ANP-TR-100, March 10, 2004A systematic, detailed major component and system design evaluation and multiple parameter optimization under practical constraints has been performed of the family of supercritical CO2 Brayton power cycles for application to advanced nuclear reactors. The recompression cycle is shown to excel with respect to simplicity, compactness, cost and thermal efficiency.Motivation.
Objectives and contributions.
Report organization.
Background and history.Supercritical CO2 cycle – characteristics and variations.
History of the supercritical CO2 cycle.
Feher’s cycle.
Condensation cycles and cycles with sub-critical temperature.
150 kWe feher cycle test loop.
Case study designs.
Binary supercritical CO2 – water vapor cycle.
ECAS study.
Supercritical CO2 cycle for shipboard application.
Supercritical CO2 cycle – the REVIVAL.
Supercritical CO2 cycle at the Czech technical university.
Supercritical CO2 cycle at the Tokyo institute of technology.
Supercritical CO2 cycle at other institutes.Computational models.
Cycles code philosophy.
Subroutines compress and expand.
Heat exchanger subroutines.
Heat transfer model.
Pressure drop model.
Heat exchanger modeling.
Subroutine PCHEvol.
Subroutine PCHElen.
Subroutine PRECOOLER.
Subroutine RECUP.
Cycle routines.
Subroutine SIMPCYC.
Subroutine RECOMP.
Program cycles.Thermodynamic analysis of supercritical carbon dioxide Brayton cycles.
Brayton cycle without inter-cooling and re-heating.
Description of the analysis.
Pressure ratio studies.
Optimization methodology for the Brayton cycles.
Total heat exchanger volume studies.
Re-heated and inter-cooled Brayton cycle.
Re-heated Brayton cycle.
Inter-cooled Brayton cycle.Compound Brayton cycles.Pre-compression cycle.
Partial cooling cycle.
Partial cooling cycle with improved regeneration.
Recompression cycle.
Comparison of advanced supercritical cycle layouts.Thermodynamic analysis of recompression cycle.Pressure ratio studies.
Study of required heat exchanger volume.
Effect of minimum operating temperature.
Effect of maximum operating pressure and temperature.
Effect of primary system or intermediate heat exchanger pressure drop.
Effect of re-heating.Indirect cycle.Methodology.
Primary loop description.
Helium primary system.
Lead bismuth alloy primary system.
Helium indirect cycle.
Indirect helium/supercritical CO2 recompression cycle.
Indirect helium single and double re-heated supercritical CO2 recompression cycle.
Comparison of different helium indirect cycle options.
Lead alloy/CO2 indirect cycle.
Comparison of re-heated and non-reheated indirect cycle.Economic analysis.Evaluation methodology.
Comparison of steam and helium Brayton cycles from GCRA.
Cost of heat exchangers.
Cost of turbomachinery.
Direct cycle cost.
Discussion of changes for the supercritical CO2 cycle.
Cost estimations.Component description and selected design issues.Heat exchangers.
Description of the HEATRIC PCHEs.
Effect of conduction length on the heat exchanger volume.
Effect of wavy channels on PCHE performance.
Simplified stress analysis for PCHE design calculations.
Turbomachinery design.
Compressor design.
Turbine design.
Turbomachinery comparison.Reference cycle and plant layout.
Operating conditions and cycle characteristics.
Net efficiency estimation.
Supercritical CO2 power conversion unit layout.
Recuperators.
Turbomachinery.
Supercritical CO2 cycle power conversion unit.Control scheme design for the recompression cycle.
Control scheme description.
Pressure control (inventory control).
Bypass control.
Temperature control.
Control strategy description – conclusions.
Control schemes for the supercritical CO2 recompression cycle.
Bypass control.
Pressure control (inventory control).Comparison with other advanced power cycles.
Supercritical recompression cycle vs. Helium Brayton cycle.
Helium Brayton cycle with multiple re-heat and inter-cooling.
Efficiency and system complexity comparison.
Summary, conclusions and recommendations for future work.
Summary and conclusions.
Optimization methodology.
Selection of the optimum cycle layout.
Selection of the optimum heat exchanger volume.
Selection of operating conditions.
Description of selected designs.
Indirect cycle.
Control scheme design.
Economics.
Efficiency comparisons with other power cycle options.
The main drawbacks and disadvantages.
Conclusions.
Recommendations for future work.Appendix a cost data base and cost estimation.s