Exergy and Exergoeconomic Analyses Based on Recompression Cycle of the Supercritical CO2 Brayton Cycle for Sodium-cooled Fast Reactor

2019 ◽  
Author(s):  
Min XIE ◽  
Yonghui XIE ◽  
Qiuhong ZHANG ◽  
Chunwei ZHANG ◽  
Aihua DONG ◽  
...  
Keyword(s):  
Fast Reactor ◽  
Supercritical Co2 ◽  
Brayton Cycle ◽  
Recompression Cycle

scholarly journals Multi-objective optimization on supercritical CO2 recompression brayton cycle using Kriging surrogate model

2017 ◽  
Vol 21 (suppl. 1) ◽  
pp. 309-316
Author(s):  
Lei Sun ◽  
Chongyu Wang ◽  
Di Zhang
Keyword(s):  
Supercritical Co2 ◽  
Thermodynamic Cycle ◽  
Brayton Cycle ◽  
Time Cost ◽  
Multi Objective Optimization ◽  
Multi Objective ◽  
Research Fields ◽  
Cycle Efficiency ◽  
Recompression Cycle ◽  
Selection Of

Supercritical CO2 cycle has become one of the most popular research fields of thermal science. The selection of operation parameters on thermodynamic cycle process is an important task. The computational model of supercritical CO2 recompression cycle is built to solve the multi-objective problem in this paper. Then, the optimization of parameters is performed based on genetic algorithm. Several Kriging models are also used to reduce the quantity of samples. According to the calculation, the influence of sample quantity on the result and the time cost is obtained. The results show that it is required to improve the heat transfer when improvement of the cycle efficiency is desired.

scholarly journals The application of supercritical CO2 in nuclear engineering: A review

2018 ◽  
Vol 10 (4) ◽  
pp. 149-158 ◽  
Author(s):  
Houbo Qi ◽  
Nan Gui ◽  
Xingtuan Yang ◽  
Jiyuan Tu ◽  
Shengyao Jiang
Keyword(s):  
Supercritical Fluids ◽  
Supercritical Co2 ◽  
Low Cost ◽  
Reactor Core ◽  
Temperature Stability ◽  
Nuclear Industry ◽  
Brayton Cycle ◽  
Nuclear Engineering ◽  
Rapid Progress ◽  
Recompression Cycle

Due to its advantages of low critical pressure and temperature, stability, non-toxic, abundant reserves and low cost, supercritical CO2 becomes one of the most common supercritical fluids in modern researches and industries. This paper presents an overview focusing on the researches of supercritical CO2 in nuclear engineering and prospects its applications in the field of nuclear industry. This review includes the recent progresses of supercritical CO2 research as: (1) energy conversion material in both recompression cycle and Brayton cycle and its applicability in Generation IV reactors; (2) reactor core coolant in the Echogen power system and reactors at MIT, Kaist and Japan, and other applications, e.g. hydrogen production. Based on the rapid progress of research, the supercritical CO2 is considered to be the most promising material in nuclear industries.

Supercritical CO2 Cycle for Fast Gas-Cooled Reactors

2004 ◽  
Author(s):  
Vaclav Dostal ◽  
Michael J. Driscoll ◽  
Pavel Hejzlar ◽  
Yong Wang
Keyword(s):  
Specific Volume ◽  
Supercritical Co2 ◽  
Nuclear Power ◽  
Nuclear Reactor ◽  
Attractive Alternative ◽  
Inlet Temperature ◽  
Outlet Temperature ◽  
Brayton Cycle ◽  
Property Changes ◽  
Recompression Cycle

Brayton cycles are currently being extensively investigated for possible use with nuclear reactors in order to reduce capital cost, shorten construction period and increase nuclear power plant efficiency. The main candidates are the well-known helium Brayton cycle and the less familiar supercritical CO2 cycle, which has been given increased attention in the past several years. The main advantage of the supercritical CO2 cycle is comparable efficiency with the helium Brayton cycle at significantly lower temperature (550°C/823K), but higher pressure (20MPa/200 normal atmospheres). By taking advantage of the abrupt property changes near the critical point of CO2 the compression work can be reduced, which results in a significant efficiency improvement. Among the surveyed compound cycles the recompression cycle offers the highest efficiency, while still retaining simplicity. The turbomachinery is highly compact and achieves efficiencies of more than 90%. Preliminary assessment of the control scheme has been performed as well. It was found that conventional inventory control could not be applied to the supercritical CO2 recompression cycle. The conventional bypass control is applicable. The reference cycle achieves 46% thermal efficiency at the compressor outlet pressure of 20MPa and turbine inlet temperature of 550°C. The sizing of the heat exchangers and turbomachinery has been performed. The recuperator specific volume is 0.39m3/MWe and pre-cooler specific volume 0.08m3/MWe. For the reference 600MWth reactor this translates to ∼ 99m3 heat exchanger core for the recuperator and ∼ 21m3 for the pre-cooler. Overall the cycle offers an attractive alternative to the steam cycle. The supercritical CO2 cycle is well suited to any type of nuclear reactor with core outlet temperature above ∼ 500°C.

Transient Simulation of Critical Flow With Thermal-Hydraulic System Analysis Code for Supercritical CO2 Applications

2017 ◽  
Author(s):  
Min Seok Kim ◽  
Bong Seong Oh ◽  
Jin Su Kwon ◽  
Hwa-Young Jung ◽  
Jeong Ik Lee
Keyword(s):  
Fast Reactor ◽  
Hydraulic System ◽  
Supercritical Co2 ◽  
Flow Resistance ◽  
System Analysis ◽  
Rankine Cycle ◽  
Transient Simulation ◽  
Critical Flow ◽  
Leakage Flow ◽  
Brayton Cycle

As a part of Sodium-cooled Fast Reactor (SFR) development, the supercritical CO2 (S-CO2) Brayton cycle is considered as an alternative power conversion system to eliminate sodium-water reaction (SWR) from the current conventional steam Rankine cycle is utilized with SFR. The leakage flow of S-CO2 from turbo-machinery via seal becomes one of important issues since not only it influences the cycle efficiency due to parasitic loss but also it is important for evaluating the system safety under various operating conditions. Thus, a transient simulation for estimating the critical flow in a turbo-machinery seal is essential to predict the leakage flow rate and calculate the required total mass of working fluid in a S-CO2 power system. This paper briefly reviews the advantages of supercritical CO2 Brayton cycle relative to a typical steam Rankine cycle used in the Sodium-cooled Fast Reactor. In addition, this paper describes the test data using a CO2 critical flow experimental facility with three orifice configurations to model the flow resistance of a rotating shaft labyrinth seal. This data is used for validation of an existing transient analytical tool developed for transient hydraulic system analysis. Contained within this code is the analysis approach of Henry/Fauske from 1971 for two phase critical flow of one-component mixtures. This paper presents prediction of transient pressure, temperature, and flow profiles for critical and sub-critical flows of CO2 relative to blowdown test data to show that reasonable results are obtained. Similar analyses relative to test results of three orifice configurations are conducted and it shows that multiple orifices increase the time to equalize pressure in the blowdown system and therefore equates to higher flow resistance and lower leakage.

Numerical investigation on the performance of impeller back seal configuration in a supercritical CO2 radial-inflow turbine

2021 ◽  
pp. 095440622110095
Author(s):  
Qiuwan Du ◽  
Yuqi Wang ◽  
Di Zhang ◽  
Yonghui Xie
Keyword(s):  
Numerical Investigation ◽  
Supercritical Co2 ◽  
Labyrinth Seal ◽  
Brayton Cycle ◽  
Mechanical Seal ◽  
Nozzle Outlet ◽  
Excellent Performance ◽  
Core Component ◽  
Comprehensive Performance ◽  
Radial Inflow Turbine

Radial-inflow turbine is a core component in supercritical CO2 (SCO2) Brayton cycle. The leakage from the nozzle outlet towards the impeller back brings a great challenge to the efficiency and security of the power system. In this paper, the labyrinth seal (LS) and dry gas seal (DGS) are arranged on the impeller back of a SCO2 radial-inflow turbine and the influence on the comprehensive performance is investigated. Results demonstrate that both LS and DGS configurations can significantly reduce leakage of the impeller back and DGS configuration performs better. Compared with the configuration without leakage, the power and efficiency of DGS configuration are only reduced by 0.27% and 0.35% respectively. The seal clearance and the inlet width have a greater effect on LS configuration. The thermo-mechanical seal deformation values of DGS configurations are all less than 8 μm, which verifies the feasibility. Finally, a novel combined seal configuration with both LS and DGS is proposed and excellent performance is achieved, providing a potential approach for the sealing problem of SCO2 radial-inflow turbine.

Optimization of Supercritical CO2 Brayton Cycle for Simple Cycle Gas Turbines Exhaust Heat Recovery Using Genetic Algorithm

2017 ◽  
Author(s):  
Akshay Khadse ◽  
Lauren Blanchette ◽  
Jayanta Kapat ◽  
Subith Vasu ◽  
Kareem Ahmed
Keyword(s):  
Genetic Algorithm ◽  
Mass Flow Rate ◽  
Flow Rate ◽  
Supercritical Co2 ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Brayton Cycle ◽  
Exhaust Heat ◽  
Exhaust Heat Recovery

For the application of waste heat recovery (WHR), supercritical CO2 (S-CO2) Brayton power cycles offer significant suitable advantages such as compactness, low capital cost and applicable to a broad range of heat source temperatures. The current study is focused on thermodynamic modelling and optimization of Recuperated (RC) and Recuperated Recompression (RRC) S-CO2 Brayton cycles for exhaust heat recovery from a next generation heavy duty simple cycle gas turbine using a genetic algorithm. The Genetic Algorithm (GA) is mainly based on bio-inspired operators such as crossover, mutation and selection. This non-gradient based algorithm yields a simultaneous optimization of key S-CO2 Brayton cycle decision variables such as turbine inlet temperature, pinch point temperature difference, compressor pressure ratio. It also outputs optimized mass flow rate of CO2 for the fixed mass flow rate and temperature of the exhaust gas. The main goal of the optimization is to maximize power out of the exhaust stream which makes it single objective optimization. The optimization is based on thermodynamic analysis with suitable practical assumptions which can be varied according to the need of user. Further the optimal cycle design points are presented for both RC and RRC configurations and comparison of net power output is established for waste heat recovery.

scholarly journals A Novel Solar Receiver for Supercritical CO2 Brayton Cycle

2019 ◽  
Vol 158 ◽  
pp. 339-344 ◽  
Author(s):  
Liang Teng ◽  
Yimin Xuan
Keyword(s):  
Supercritical Co2 ◽  
Brayton Cycle ◽  
Solar Receiver

scholarly journals Characteristics of a gas-cooled fast reactor with minor actinide loading

2021 ◽  
Vol 8 (2) ◽  
pp. 1-9
Author(s):  
Hoai Nam Tran ◽  
Yasuyoshi Kato ◽  
Van Khanh Hoang ◽  
Sy Minh Tuan Hoang
Keyword(s):  
Fast Reactor ◽  
Supercritical Co2 ◽  
Cycle Length ◽  
Minor Actinide ◽  
Co2 Gas ◽  
Control Rod ◽  
The Core ◽  
Thermal Output ◽  
Long Life ◽  
Gas Turbine Cycle

This paper presents the neutronics characteristics of a prototype gas-cooled (supercritical CO2-cooled) fast reactor (GCFR) with minor actinide (MA) loading in the fuel. The GCFR core is designed with a thermal output of 600 MWt as a part of a direct supercritical CO2 (S-CO2) gas turbine cycle. Transmutation of MAs in the GCFR has been investigated for attaining low burnup reactivity swing and reducing long-life radioactive waste. Minor actinides are loaded uniformly in the fuel regions of the core. The burnup reactivity swing is minimized to 0.11% ∆k/kk’ over the cycle length of 10 years when the MA content is 6.0 wt%. The low burnup reactivity swing enables minimization of control rod operation during burnup. The MA transmutation rate is 42.2 kg/yr, which is equivalent to the production rates in 7 LWRs of the same electrical output.

scholarly journals Preliminary prospects of a Pumped Thermal Energy Storage (PTES) based on a supercritical CO2 Brayton cycle

2021 ◽  
Author(s):  
Karin Astrid Senta Edel ◽  
František Hrdlička ◽  
Václav Novotný
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Supercritical Co2 ◽  
Storage Systems ◽  
Renewable Energy Sources ◽  
Brayton Cycle ◽  
Term Energy ◽  
Weather Changes

As part of the change towards a higher deployment of renewable energy sources, which naturally deliver energy intermittently, the need for energy storage systems is increasing. For compensation of disturbance in power production due to inter-day to seasonal weather changes, long-term energy storage is required. In the spectrum of storage systems, one out of a few geographically independent possibilities is the storage of electricity in heat, so-called Carnot-Batteries. This paper presents a Pumped Thermal Energy Storage (PTES) system based on a recuperated supercritical CO2 Brayton cycle. The modelled system provides a round-trip efficiency of 38.9%.

Sign in / Sign up

Export Citation Format

Share Document