The study of thermal characteristics during startup is one of the most important aspects for safety analysis of supercritical water-cooled reactor(SCWR).According to the given sliding pressure mode of SCWR,thermal ana...The study of thermal characteristics during startup is one of the most important aspects for safety analysis of supercritical water-cooled reactor(SCWR).According to the given sliding pressure mode of SCWR,thermal analysis on temperature-raising phase and power-raising phase of startup are carried out.Considering the radial heterogeneity of power distribution,thermal characteristics for different assemblies during startup are also put forward.The results show that,during temperature-raising phase with core power increased only,the temperature of moderator,coolant and fuel cladding in inner assemblies are increased with little amplitude.During power-raising phase with core power and feed-water flow rate increased,the coolant temperature keeps unchanged,but the moderator temperature is decreased.With a greater variation of power,fuel cladding temperature shows a greater increase.Furthermore,considering the uneven distribution of radial power,thermo-hydraulic characteristics with uneven cladding temperature distribution shows a certain horizontal heterogeneity for different fuel assemblies,which becomes serious as flow rate and power increase.By adjusting flow rate distribution in different fuel assemblies or changing power setting during startup,the cladding temperature difference could be effectively reduced,which provides a certain reference for startup optimization of SCWR.展开更多
There are two main theories, the 'temperature-raising' theory and the 'precipitation-based regulation' theory, which guide the optimum sowing time of the plastic-film corn. The former was applied in th...There are two main theories, the 'temperature-raising' theory and the 'precipitation-based regulation' theory, which guide the optimum sowing time of the plastic-film corn. The former was applied in the humid or semi-humid ecotope and on irrigated or half-shaded land in the arid and semi-arid ecotopes, while the latter was suitable for the dry-farming land in the semi-arid ecotope. The results of experiments and investigations for many years showed that the corn output was increased by 69.2% when the former theory was applied to guide the optimum sowing time for plastic-film corn in the semi-humid ecotope, and by 60. 0% when the latter theory was applied in the semi-arid ecotope. In the semi-arid ecotope, however, the output was increased only by 15.7% when the former theory was applied, and even dropped by 14.4% when the latter theory was applied.展开更多
基金Supported by National Basic Research Program of China (No. 2007CB209804)State Key Laboratory of Reactor System Design Technology (No. 2011-153)the Fundamental Research Funds for the Key Universities (No. 11QX51)
文摘The study of thermal characteristics during startup is one of the most important aspects for safety analysis of supercritical water-cooled reactor(SCWR).According to the given sliding pressure mode of SCWR,thermal analysis on temperature-raising phase and power-raising phase of startup are carried out.Considering the radial heterogeneity of power distribution,thermal characteristics for different assemblies during startup are also put forward.The results show that,during temperature-raising phase with core power increased only,the temperature of moderator,coolant and fuel cladding in inner assemblies are increased with little amplitude.During power-raising phase with core power and feed-water flow rate increased,the coolant temperature keeps unchanged,but the moderator temperature is decreased.With a greater variation of power,fuel cladding temperature shows a greater increase.Furthermore,considering the uneven distribution of radial power,thermo-hydraulic characteristics with uneven cladding temperature distribution shows a certain horizontal heterogeneity for different fuel assemblies,which becomes serious as flow rate and power increase.By adjusting flow rate distribution in different fuel assemblies or changing power setting during startup,the cladding temperature difference could be effectively reduced,which provides a certain reference for startup optimization of SCWR.
文摘There are two main theories, the 'temperature-raising' theory and the 'precipitation-based regulation' theory, which guide the optimum sowing time of the plastic-film corn. The former was applied in the humid or semi-humid ecotope and on irrigated or half-shaded land in the arid and semi-arid ecotopes, while the latter was suitable for the dry-farming land in the semi-arid ecotope. The results of experiments and investigations for many years showed that the corn output was increased by 69.2% when the former theory was applied to guide the optimum sowing time for plastic-film corn in the semi-humid ecotope, and by 60. 0% when the latter theory was applied in the semi-arid ecotope. In the semi-arid ecotope, however, the output was increased only by 15.7% when the former theory was applied, and even dropped by 14.4% when the latter theory was applied.
