针对传统的铅冷快堆非能动余热排出系统设计中存在开发效率低、迭代周期长、模型二义性等前期需求问题,本研究将基于模型的系统工程(Model-based System Engineering,MBSE)方法应用于铅冷快堆非能动余热排出系统设计需求中,结合设计流...针对传统的铅冷快堆非能动余热排出系统设计中存在开发效率低、迭代周期长、模型二义性等前期需求问题,本研究将基于模型的系统工程(Model-based System Engineering,MBSE)方法应用于铅冷快堆非能动余热排出系统设计需求中,结合设计流程进行系统架构的初步设计,该系统架构由需求分析、功能分析和设计综合三部分组成。结果表明:需求分析阶段生成的需求图和用例图可捕获系统需求并确定系统顶层用例;功能分析阶段绘制的时序图、活动图和状态机图可形成系统功能模型并提供早期确认与验证;设计综合阶段建立的白盒模型最终实现系统架构的分析与设计。采用该方法设计的系统架构可确保前后设计需求一致性,进一步降低设计风险并提高设计效率,可为数字化铅冷快堆非能动余热排出系统设计与优化提供应用参考。展开更多
In this study,a multi-physics and multi-scale coupling program,Fluent/KMC-sub/NDK,was developed based on the user-defined functions(UDF)of Fluent,in which the KMC-sub-code is a sub-channel thermal-hydraulic code and t...In this study,a multi-physics and multi-scale coupling program,Fluent/KMC-sub/NDK,was developed based on the user-defined functions(UDF)of Fluent,in which the KMC-sub-code is a sub-channel thermal-hydraulic code and the NDK code is a neutron diffusion code.The coupling program framework adopts the"master-slave"mode,in which Fluent is the master program while NDK and KMC-sub are coupled internally and compiled into the dynamic link library(DLL)as slave codes.The domain decomposition method was adopted,in which the reactor core was simulated by NDK and KMC-sub,while the rest of the primary loop was simulated using Fluent.A simulation of the reactor shutdown process of M2LFR-1000 was carried out using the coupling program,and the code-to-code verification was performed with ATHLET,demonstrating a good agreement,with absolute deviation was smaller than 0.2%.The results show an obvious thermal stratification phenomenon during the shutdown process,which occurs 10 s after shutdown,and the change in thermal stratification phenomena is also captured by the coupling program.At the same time,the change in the neutron flux density distribution of the reactor was also obtained.展开更多
铅铋共晶(lead-bismutheutectic,LBE)合金具有化学活性低、热特性杰出、耐辐照等优异特性,在核领域具有广泛的应用前景,是第4代核能系统铅冷快堆(lead-cooled fast reactor,LFR)冷却剂的首选材料。然而,高温、高流速、高密度的液态LBE...铅铋共晶(lead-bismutheutectic,LBE)合金具有化学活性低、热特性杰出、耐辐照等优异特性,在核领域具有广泛的应用前景,是第4代核能系统铅冷快堆(lead-cooled fast reactor,LFR)冷却剂的首选材料。然而,高温、高流速、高密度的液态LBE会对核电材料造成严重腐蚀,威胁其服役安全。因此,全面认识与分析应用LBE所面临的挑战,对于解决LBE与结构材料相容性的关键科学和实际工程问题,以及核能的可持续发展具有重要意义。简介了LBE冷却剂的特点,系统地论述了近年来关于LBE腐蚀机理、影响因素的研究现状,针对目前的控制溶解氧气浓度、结构材料设计和腐蚀防护涂层这3种主要解决方案的基本原理、防护机制及国内外最新研究进展进行了较为全面地分析。最后,总结了目前研究中存在的主要问题与不足,并展望了未来发展前景。展开更多
Owing to the inherent instability of the natural circulation system,flow instability can easily occur during the operation of a natural circulation lead-cooled fast reactor,especially during the startup phase.A compre...Owing to the inherent instability of the natural circulation system,flow instability can easily occur during the operation of a natural circulation lead-cooled fast reactor,especially during the startup phase.A comprehensive startup scheme for SNCLFR-100,including primary and secondary circuits,is proposed in this paper.It references existing more mature startup schemes in various reactor types.It additionally considers the restriction conditions on the power increase in other schemes and the characteristics of lead-based coolant.On this basis,the multi-scale coupling code ATHLET-OpenFOAM was used to study the flow instability in the startup phase under different power-step amplitudes and power duration times.The results showed that obvious flow instability phenomena were found in the different startup schemes,such as the short-term backflow phenomenon of the core at the initial time of the startup.Moreover,an obvious increase in the flow rate and temperature to the peak value at the later stage of a continuous power rise was observed,as well as continuous oscillations before reaching a steady state.It was determined that the scheme with smaller power-step amplitude and a longer power duration time requires more time to start the reactor.Nevertheless,it will be more conducive to the safe and stable startup of the reactor.展开更多
快堆瞬发中子寿命短,缓发中子份额小,反应性扰动下反应堆周期较压水堆短,功率变化快,控制其功率的难度很大。因此,要求快堆的控制器具有较快的响应速度和控制精度。考虑到快堆功率控制的这些难点,本文基于线性自抗扰控制(Linear Active ...快堆瞬发中子寿命短,缓发中子份额小,反应性扰动下反应堆周期较压水堆短,功率变化快,控制其功率的难度很大。因此,要求快堆的控制器具有较快的响应速度和控制精度。考虑到快堆功率控制的这些难点,本文基于线性自抗扰控制(Linear Active Disturbance Rejection Control)理论设计了分别带有模型信息和不带模型信息的两个控制器。导出了用于自抗扰控制器设计的相对功率的二阶非线性模型和对应的线性扩张状态观测器(Linear Extended State Observer)。通过调试确定了线性扩张状态观测器带宽的值。最终仿真的结果表明,两个控制器都适用于铅冷快堆(Lead-cooledFast Reactor)的功率控制,均有较快的调节速度与精度,并且加入模型信息的线性自抗扰控制器拥有更准确的总扰动估计效果,优秀的控制性能以及更良好的抗扰效果。展开更多
Motivated to understand the pressure-buildup characteristics in a circumstance of a water droplet immerged inside a heavy liquid metal pool,which is a key phenomenon during a Steam Generator Tube Rupture accident of L...Motivated to understand the pressure-buildup characteristics in a circumstance of a water droplet immerged inside a heavy liquid metal pool,which is a key phenomenon during a Steam Generator Tube Rupture accident of Lead-cooled Fast Reactor,many experiments have been conducted by injecting water lumps into a molten lead pool at Sun Yat-sen University.In order to deepen the understanding of the influence of melt material,this lead experiment was compared with a Lead-Bismuth-Eutectic(LBE)experiment in the literature.For both experiments,a steam explosion occurred in a small part of the experi-mental runs,which generally leads to strengthened pressure buildup.Regarding the non-explosion experimental cases,the impact of all parameters employed in lead experiments(i.e.,water lump volume,water lump shape,molten pool depth,and temperature of water and melt)on the pressure buildup is non-negligible and similar to that in our previous experiments using LBE.Notably,limited pressure buildup with an increase in water lump volume was also observed.A slightly more violent pressure buildup tends to appear in the lead experiments than in the LBE experiments under the same experimental conditions,which may be due to the higher thermal conductivity of lead than of LBE.In a few experimental runs with a relatively low melt temperature close to the melting point of lead,local solidification of liquid lead was observed,restricting pressure buildup.For the lead and LBE experiments,the calculated melt kinetic energy conversion efficiencyηhas a relatively small value(not exceeding 1.6%),and theηvalues have an overall positive correlation with the impulse on the molten pool.展开更多
文摘针对传统的铅冷快堆非能动余热排出系统设计中存在开发效率低、迭代周期长、模型二义性等前期需求问题,本研究将基于模型的系统工程(Model-based System Engineering,MBSE)方法应用于铅冷快堆非能动余热排出系统设计需求中,结合设计流程进行系统架构的初步设计,该系统架构由需求分析、功能分析和设计综合三部分组成。结果表明:需求分析阶段生成的需求图和用例图可捕获系统需求并确定系统顶层用例;功能分析阶段绘制的时序图、活动图和状态机图可形成系统功能模型并提供早期确认与验证;设计综合阶段建立的白盒模型最终实现系统架构的分析与设计。采用该方法设计的系统架构可确保前后设计需求一致性,进一步降低设计风险并提高设计效率,可为数字化铅冷快堆非能动余热排出系统设计与优化提供应用参考。
基金supported by Science and Technology on Reactor System Design Technology Laboratory,Chengdu,China(LRSDT2020106)
文摘In this study,a multi-physics and multi-scale coupling program,Fluent/KMC-sub/NDK,was developed based on the user-defined functions(UDF)of Fluent,in which the KMC-sub-code is a sub-channel thermal-hydraulic code and the NDK code is a neutron diffusion code.The coupling program framework adopts the"master-slave"mode,in which Fluent is the master program while NDK and KMC-sub are coupled internally and compiled into the dynamic link library(DLL)as slave codes.The domain decomposition method was adopted,in which the reactor core was simulated by NDK and KMC-sub,while the rest of the primary loop was simulated using Fluent.A simulation of the reactor shutdown process of M2LFR-1000 was carried out using the coupling program,and the code-to-code verification was performed with ATHLET,demonstrating a good agreement,with absolute deviation was smaller than 0.2%.The results show an obvious thermal stratification phenomenon during the shutdown process,which occurs 10 s after shutdown,and the change in thermal stratification phenomena is also captured by the coupling program.At the same time,the change in the neutron flux density distribution of the reactor was also obtained.
文摘铅铋共晶(lead-bismutheutectic,LBE)合金具有化学活性低、热特性杰出、耐辐照等优异特性,在核领域具有广泛的应用前景,是第4代核能系统铅冷快堆(lead-cooled fast reactor,LFR)冷却剂的首选材料。然而,高温、高流速、高密度的液态LBE会对核电材料造成严重腐蚀,威胁其服役安全。因此,全面认识与分析应用LBE所面临的挑战,对于解决LBE与结构材料相容性的关键科学和实际工程问题,以及核能的可持续发展具有重要意义。简介了LBE冷却剂的特点,系统地论述了近年来关于LBE腐蚀机理、影响因素的研究现状,针对目前的控制溶解氧气浓度、结构材料设计和腐蚀防护涂层这3种主要解决方案的基本原理、防护机制及国内外最新研究进展进行了较为全面地分析。最后,总结了目前研究中存在的主要问题与不足,并展望了未来发展前景。
文摘Owing to the inherent instability of the natural circulation system,flow instability can easily occur during the operation of a natural circulation lead-cooled fast reactor,especially during the startup phase.A comprehensive startup scheme for SNCLFR-100,including primary and secondary circuits,is proposed in this paper.It references existing more mature startup schemes in various reactor types.It additionally considers the restriction conditions on the power increase in other schemes and the characteristics of lead-based coolant.On this basis,the multi-scale coupling code ATHLET-OpenFOAM was used to study the flow instability in the startup phase under different power-step amplitudes and power duration times.The results showed that obvious flow instability phenomena were found in the different startup schemes,such as the short-term backflow phenomenon of the core at the initial time of the startup.Moreover,an obvious increase in the flow rate and temperature to the peak value at the later stage of a continuous power rise was observed,as well as continuous oscillations before reaching a steady state.It was determined that the scheme with smaller power-step amplitude and a longer power duration time requires more time to start the reactor.Nevertheless,it will be more conducive to the safe and stable startup of the reactor.
文摘快堆瞬发中子寿命短,缓发中子份额小,反应性扰动下反应堆周期较压水堆短,功率变化快,控制其功率的难度很大。因此,要求快堆的控制器具有较快的响应速度和控制精度。考虑到快堆功率控制的这些难点,本文基于线性自抗扰控制(Linear Active Disturbance Rejection Control)理论设计了分别带有模型信息和不带模型信息的两个控制器。导出了用于自抗扰控制器设计的相对功率的二阶非线性模型和对应的线性扩张状态观测器(Linear Extended State Observer)。通过调试确定了线性扩张状态观测器带宽的值。最终仿真的结果表明,两个控制器都适用于铅冷快堆(Lead-cooledFast Reactor)的功率控制,均有较快的调节速度与精度,并且加入模型信息的线性自抗扰控制器拥有更准确的总扰动估计效果,优秀的控制性能以及更良好的抗扰效果。
基金supported by the Basic and Applied Basic Research Foundation of Guangdong Province (Nos.2021A1515010343 and 2022A1515011582)the Science and Technology Program of Guangdong Province (Nos.2021A0505030026 and 2022A0505050029).
文摘Motivated to understand the pressure-buildup characteristics in a circumstance of a water droplet immerged inside a heavy liquid metal pool,which is a key phenomenon during a Steam Generator Tube Rupture accident of Lead-cooled Fast Reactor,many experiments have been conducted by injecting water lumps into a molten lead pool at Sun Yat-sen University.In order to deepen the understanding of the influence of melt material,this lead experiment was compared with a Lead-Bismuth-Eutectic(LBE)experiment in the literature.For both experiments,a steam explosion occurred in a small part of the experi-mental runs,which generally leads to strengthened pressure buildup.Regarding the non-explosion experimental cases,the impact of all parameters employed in lead experiments(i.e.,water lump volume,water lump shape,molten pool depth,and temperature of water and melt)on the pressure buildup is non-negligible and similar to that in our previous experiments using LBE.Notably,limited pressure buildup with an increase in water lump volume was also observed.A slightly more violent pressure buildup tends to appear in the lead experiments than in the LBE experiments under the same experimental conditions,which may be due to the higher thermal conductivity of lead than of LBE.In a few experimental runs with a relatively low melt temperature close to the melting point of lead,local solidification of liquid lead was observed,restricting pressure buildup.For the lead and LBE experiments,the calculated melt kinetic energy conversion efficiencyηhas a relatively small value(not exceeding 1.6%),and theηvalues have an overall positive correlation with the impulse on the molten pool.
