The supercritical CO_(2) Brayton cycle is considered a promising energy conversion system for Generation IV reactors for its simple layout,compact structure,and high cycle efficiency.Mathematical models of four Brayto...The supercritical CO_(2) Brayton cycle is considered a promising energy conversion system for Generation IV reactors for its simple layout,compact structure,and high cycle efficiency.Mathematical models of four Brayton cycle layouts are developed in this study for different reactors to reduce the cost and increase the thermohydraulic performance of nuclear power generation to promote the commercialization of nuclear energy.Parametric analysis,multi-objective optimizations,and four decision-making methods are applied to obtain each Brayton scheme’s optimal thermohydraulic and economic indexes.Results show that for the same design thermal power scale of reactors,the higher the core’s exit temperature,the better the Brayton cycle’s thermo-economic performance.Among the four-cycle layouts,the recompression cycle(RC)has the best overall performance,followed by the simple recuperation cycle(SR)and the intercooling cycle(IC),and the worst is the reheating cycle(RH).However,RH has the lowest total cost of investment(C_(tot))of$1619.85 million,and IC has the lowest levelized cost of energy(LCOE)of 0.012$/(kWh).The nuclear Brayton cycle system’s overall performance has been improved due to optimization.The performance of the molten salt reactor combined with the intercooling cycle(MSR-IC)scheme has the greatest improvement,with the net output power(W_(net)),thermal efficiencyη_(t),and exergy efficiency(η_(e))improved by 8.58%,8.58%,and 11.21%,respectively.The performance of the lead-cooled fast reactor combined with the simple recuperation cycle scheme was optimized to increase C_(tot) by 27.78%.In comparison,the internal rate of return(IRR)increased by only 7.8%,which is not friendly to investors with limited funds.For the nuclear Brayton cycle,the molten salt reactor combined with the recompression cycle scheme should receive priority,and the gas-cooled fast reactor combined with the reheating cycle scheme should be considered carefully.展开更多
The non-linear stochastic response of a jack-up platform subjected to wave load has been analyzed dynamically in this paper, and the analysis method in time domain is considered. Monte Carlo simulation is used to gene...The non-linear stochastic response of a jack-up platform subjected to wave load has been analyzed dynamically in this paper, and the analysis method in time domain is considered. Monte Carlo simulation is used to generate random sea. An emphasis is placed on the nonlinear hydrodynamic force. Several distributions for the statistical estimation of extreme responses are compared. For Gumble distribution, the parameters of its asymptotic distribution expression have been checked. The results show that the Gumble distribution agrees well with the simulated values of the responses.展开更多
In the present paper an unsteady flow of polymer fluid, i.e. non-Newtonian fluid is studied. The constitutive equation of upper-convected Maxwell fluid is used. The variational approach due to Kantorovich is used for ...In the present paper an unsteady flow of polymer fluid, i.e. non-Newtonian fluid is studied. The constitutive equation of upper-convected Maxwell fluid is used. The variational approach due to Kantorovich is used for the unsteady problem of the fluid. A special computer program `MACSYMA' is used to get the different approximation of the method of Kantorovich. The present method developed is called Computational Analytical Method which is available for the scientific research.展开更多
基金This work was supported of National Natural Science Foundation of China Fund(No.52306033)State Key Laboratory of Engines Fund(No.SKLE-K2022-07)the Jiangxi Provincial Postgraduate Innovation Special Fund(No.YC2022-s513).
文摘The supercritical CO_(2) Brayton cycle is considered a promising energy conversion system for Generation IV reactors for its simple layout,compact structure,and high cycle efficiency.Mathematical models of four Brayton cycle layouts are developed in this study for different reactors to reduce the cost and increase the thermohydraulic performance of nuclear power generation to promote the commercialization of nuclear energy.Parametric analysis,multi-objective optimizations,and four decision-making methods are applied to obtain each Brayton scheme’s optimal thermohydraulic and economic indexes.Results show that for the same design thermal power scale of reactors,the higher the core’s exit temperature,the better the Brayton cycle’s thermo-economic performance.Among the four-cycle layouts,the recompression cycle(RC)has the best overall performance,followed by the simple recuperation cycle(SR)and the intercooling cycle(IC),and the worst is the reheating cycle(RH).However,RH has the lowest total cost of investment(C_(tot))of$1619.85 million,and IC has the lowest levelized cost of energy(LCOE)of 0.012$/(kWh).The nuclear Brayton cycle system’s overall performance has been improved due to optimization.The performance of the molten salt reactor combined with the intercooling cycle(MSR-IC)scheme has the greatest improvement,with the net output power(W_(net)),thermal efficiencyη_(t),and exergy efficiency(η_(e))improved by 8.58%,8.58%,and 11.21%,respectively.The performance of the lead-cooled fast reactor combined with the simple recuperation cycle scheme was optimized to increase C_(tot) by 27.78%.In comparison,the internal rate of return(IRR)increased by only 7.8%,which is not friendly to investors with limited funds.For the nuclear Brayton cycle,the molten salt reactor combined with the recompression cycle scheme should receive priority,and the gas-cooled fast reactor combined with the reheating cycle scheme should be considered carefully.
文摘The non-linear stochastic response of a jack-up platform subjected to wave load has been analyzed dynamically in this paper, and the analysis method in time domain is considered. Monte Carlo simulation is used to generate random sea. An emphasis is placed on the nonlinear hydrodynamic force. Several distributions for the statistical estimation of extreme responses are compared. For Gumble distribution, the parameters of its asymptotic distribution expression have been checked. The results show that the Gumble distribution agrees well with the simulated values of the responses.
文摘In the present paper an unsteady flow of polymer fluid, i.e. non-Newtonian fluid is studied. The constitutive equation of upper-convected Maxwell fluid is used. The variational approach due to Kantorovich is used for the unsteady problem of the fluid. A special computer program `MACSYMA' is used to get the different approximation of the method of Kantorovich. The present method developed is called Computational Analytical Method which is available for the scientific research.
