Supercritical CO2 Brayton cycles for coal-fired power plants

Mecheri, Mounir; Moullec, Yann Le

doi:10.1016/j.energy.2016.02.111

Cited by 287 publications

(85 citation statements)

References 24 publications

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“…In recent years, the study of supercritical carbon dioxide (SCO 2 ) Brayton cycle and its components has attracted lots of attention. Various heat sources including solar power [1][2][3][4][5], nuclear power [6,7] and waste-heat utilization [8] are employed. As the key component in a Brayton cycle, the design and characteristics of turbomachinery deserve to be investigated in depth.…”

Section: Introductionmentioning

confidence: 99%

Numerical Investigation on Aerodynamic Performance of SCO2 and Air Radial-Inflow Turbines with Different Solidity Structures

Wang

Zhang

et al. 2020

Applied Sciences

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Featured Application: This work can provide the design reference of rotor solidity for SCO 2 and air radial-inflow turbines as well as a new splitter structure to improve the performance of low solidity case. Abstract: Supercritical carbon dioxide (SCO 2 ) is of great use in miniature power systems. It obtains the characteristics of high density and low viscosity, which makes it possible to build a compact structure for turbomachinery. For a turbine design, an important issue is to figure out the appropriate solidity of the rotor. The objective of this research is to present the aerodynamic performance and provide the design reference for SCO 2 and air radial-inflow turbines considering different solidity structures. For the low solidity case of SCO 2 turbine, new splitter structures are proposed to improve its performance. The automatic design and simulation process are established by batch modes in MATLAB. The numerical investigation is based on a 3D viscous compressible N-S equation and the actual fluid property of SCO 2 and air. The distributions of flow parameters are first presented. Rotor blade load and aerodynamic force are then thoroughly analyzed and the aerodynamic performances of all cases are obtained. The SCO 2 turbine has larger power capacity and higher efficiency while the performance of the air turbine is less affected by rotor solidity. For both SCO 2 and air, small solidity can cause the unsatisfactory flow condition at the inlet and the shroud section of the rotor, while large solidity results in the aerodynamic loss at the trailing edge of rotor blade and the hub of rotor outlet. A suction side offset splitter can greatly improve the performance of the low solidity SCO 2 turbine.3 of 18 and working fluid used in the calculation are determined. The macro files of batch mode are called by MATLAB to execute the process in Workbench BladeGen, Turbogrid, CFX, and CFD-Post. The modeling, discretization, numerical simulation and post-processing are then completed. Finally, the program repeats this procedure to obtain the results of the required different cases.Appl. Sci. 2020, 10, x FOR PEER REVIEW 3 of 18 solidity and working fluid used in the calculation are determined. The macro files of batch mode are called by MATLAB to execute the process in Workbench BladeGen, Turbogrid, CFX, and CFD-Post. The modeling, discretization, numerical simulation and post-processing are then completed. Finally, the program repeats this procedure to obtain the results of the required different cases.

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Section: Introductionmentioning

confidence: 99%

Numerical Investigation on Aerodynamic Performance of SCO2 and Air Radial-Inflow Turbines with Different Solidity Structures

Wang

Zhang

et al. 2020

Applied Sciences

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“…S‐CO 2 systems are universal, are efficient, and have small footprint. Due to these advantages, S‐CO 2 systems are widely researched for the next generation heat‐power conversion systems such as solar power, fossil fuel, waste heat recovery, and nuclear energy …”

Section: Introductionmentioning

confidence: 99%

“…13,14 S-CO 2 systems are universal, are efficient, and have small footprint. Due to these advantages, S-CO 2 systems are widely researched for the next generation heat-power conversion systems such as solar power, [15][16][17] fossil fuel, 18 waste heat recovery, 19,20 and nuclear energy. 13,14,21 KAIST-MMR is a 10-MWe scale S-CO 2 direct-cycle SMR designed to operate for 20 years without fuel reloading.…”

Section: Introductionmentioning

confidence: 99%

Radionuclide transport in a long‐term operation supercritical CO ₂ ‐cooled direct‐cycle small nuclear reactor

Son

Kwon

et al. 2020

Int J Energy Res

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Summary In recent years, to overcome the challenges of nuclear power plants due to their large scale, numerous types of small modular reactors are being designed worldwide. Small modular reactors are required to have a capability to operate in environmentally challenging regions with long refueling time. Supercritical CO2 (S‐CO2)‐cooled direct‐cycle reactor is one of the candidates that can meet these requirements. In order to evaluate if the design achieves this goal, transport of generated radionuclides from the long‐term operation has to be evaluated in order to estimate the radioactivity accumulation in the system. However, existing radionuclide transport evaluation method does not reflect the characteristics of supercritical fluids properly. In this paper, the fission product plate‐out behavior of Korea Advanced Institute of Science and Technology Micro Modular Reactor (KAIST‐MMR), a 10‐MWe class S‐CO2‐cooled fast reactor with direct S‐CO2 power conversion system, is studied. The evaluation methodology was developed via integrating suitable models while considering the shape of the nuclear fuel, component geometries, characteristics of a working fluid in supercritical state, and the fast reactor design. As a result of the analysis, the degree of plate‐out of KAIST‐MMR is not expected to have serious radioactivity accumulation within the components. Most of the sorption occurred at the turbine and recuperator hot‐side inlet region. In particular, the dose rate of the turbine was quite low, because the size of the turbine is very small.

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“…The net lower heating value (LHV) plant efficiency without CO 2 capture for a maximal temperature and pressure of 620 ∘ C and 30Mpa could achieve 50.3% and 4.8% higher than supercritical steam power plant. Mecheri and Moullec [17] investigated the S-CO 2 system performance and still recommended the previous layout. Li et al [18] set up an additional split flow economizer before the air preheater to heat the CO 2 from low temperature recuperator (LTR) and had accomplished 5MWe fossil-based S-CO 2 recompression and reheat integral test facility design.…”

Section: Introductionmentioning

confidence: 99%

Thermodynamic Analysis of Supercritical CO₂ Power Cycle with Fluidized Bed Coal Combustion

Geng

Shao

Zhong

et al. 2018

Journal of Combustion

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Closed supercritical carbon dioxide (S-CO 2 ) Brayton cycle is a promising alternative to steam Rankine cycle due to higher cycle efficiency at equivalent turbine inlet conditions, which has been explored to apply to nuclear, solar power, waste heat recovery, and coal-fired power plant. This study establishes 300MW S-CO 2 power system based on modified recompression Brayton cycle integrated with coal-fired circulating fluidized bed (CFB) boiler. The influences of two stages split flow on system performance have been investigated in detail. In addition, thermodynamic analysis of critical operating parameters has been carried out, including terminal temperature difference, turbine inlet pressure/temperature, reheat stages, and parameters as well as compressor inlet pressure/temperature. The results show that rational distribution of split ratio to the recompressor (SR 1 ) achieves maximal cycle efficiency where heat capacities of both sides in the low temperature recuperator (LTR) realize an excellent matching. The optimal SR 1 decreases in the approximately linear proportion to high pressure turbine (HPT) inlet pressure due to gradually narrowing specific heat differences in the LTR. Secondary split ratio to the economizer of CFB boiler (SR 2 ) can recover moderate flue gas heat caused by narrow temperature range and improve boiler efficiency. Smaller terminal temperature difference corresponds to higher efficiency and brings about larger cost and pressure drops of the recuperators, which probably decrease efficiency conversely. Single reheat improves cycle efficiency by 1.5% under the condition of 600 ∘ C/600 ∘ C/25Mpa while efficiency improvement for double reheat is less obvious compared to steam Rankine cycle largely due to much lower pressure ratio. Reheat pressure and main compressor (MC) inlet pressure have corresponding optimal values. HPT and low pressure turbine (LPT) inlet temperature both have positive influences on system performance.

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Supercritical CO2 Brayton cycles for coal-fired power plants

Cited by 287 publications

References 24 publications

Numerical Investigation on Aerodynamic Performance of SCO2 and Air Radial-Inflow Turbines with Different Solidity Structures

Numerical Investigation on Aerodynamic Performance of SCO2 and Air Radial-Inflow Turbines with Different Solidity Structures

Radionuclide transport in a long‐term operation supercritical CO ₂ ‐cooled direct‐cycle small nuclear reactor

Thermodynamic Analysis of Supercritical CO₂ Power Cycle with Fluidized Bed Coal Combustion

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Supercritical CO2 Brayton cycles for coal-fired power plants

Cited by 287 publications

References 24 publications

Numerical Investigation on Aerodynamic Performance of SCO2 and Air Radial-Inflow Turbines with Different Solidity Structures

Numerical Investigation on Aerodynamic Performance of SCO2 and Air Radial-Inflow Turbines with Different Solidity Structures

Radionuclide transport in a long‐term operation supercritical CO 2 ‐cooled direct‐cycle small nuclear reactor

Thermodynamic Analysis of Supercritical CO2 Power Cycle with Fluidized Bed Coal Combustion

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Product

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Radionuclide transport in a long‐term operation supercritical CO ₂ ‐cooled direct‐cycle small nuclear reactor

Thermodynamic Analysis of Supercritical CO₂ Power Cycle with Fluidized Bed Coal Combustion