The technology of passive safety is the current trend among safety systems in nuclear power plant. Pas- sive residual heat removal system (PRHRS), a major part of passive safety systems of Chinese advanced PWR, is a n...The technology of passive safety is the current trend among safety systems in nuclear power plant. Pas- sive residual heat removal system (PRHRS), a major part of passive safety systems of Chinese advanced PWR, is a novel design with three-fold natural circulation. On the basis of reasonable physics and mathematics models, MI- TAP-PRHRS code was developed to analyze steady and transient characteristics of the PRHRS. The calculation and analysis show that the code simulates steady characteristics of the PRHRS very well, and it is able to simulate tran- sient characteristics of all startup modes of the PRHRS. However, the quantitative description is poor during the ini- tial stages of the transition process when water hammer occurs.展开更多
Three different kinds of experiments and their typical results are surveyed for the passive residual heat removal system (PRHRS) of PWR performed in Nuclear Power Institute of China (NPIC) recent ten years. The typi- ...Three different kinds of experiments and their typical results are surveyed for the passive residual heat removal system (PRHRS) of PWR performed in Nuclear Power Institute of China (NPIC) recent ten years. The typi- cal results of MISAP, a special code for PWR passive residual heat removal system developed and assessed by NPIC, are also described briefly in this paper.展开更多
Thermal-hydraulic characteristic investigation on passive residual heat removal system (PRHRS) of Chinese advanced PWR was conducted to provide input data for PRHRS design and to demonstrate the feasibility of unique ...Thermal-hydraulic characteristic investigation on passive residual heat removal system (PRHRS) of Chinese advanced PWR was conducted to provide input data for PRHRS design and to demonstrate the feasibility of unique design features. A total of 237 sets of test data at steady state have been obtained and the main influence factors on the two-phase natural circulation flow rate and residual heat removal capability were identified. On the basis of theory analysis, a correlation of two-phase natural circulation was obtained, and relative errors of 95% test data were less than ±16%. There is a considerable effect of the system status parameters on the threshold of height between heat source and heat sink, and its correlation of two-phase natural circulation system has been obtained. The steady characteristic research shows that PRHRS has the capability of removing the core decay power through natural circulation.展开更多
The tube inside and outside heat transfer mechanism of Passive Residual Heat Removal Heat Exchanger (PRHR HX) was analyzed. The calculation method of this special heat exchanger under natural convection condition in I...The tube inside and outside heat transfer mechanism of Passive Residual Heat Removal Heat Exchanger (PRHR HX) was analyzed. The calculation method of this special heat exchanger under natural convection condition in In-containment Refueling Water Storage Tank (IRWST) was carried out. The single-tube coupling model three-dimensional natural circulation in the IRWST was simulated numerically using Fluent. The heat transfer and flow characteristics of the fluid in IRWST were obtained. The comparison of the results between theoretical arithmetic and numerical simulation showed that the theoretical calculation method is suitable for the heat transfer calculation of PRHR HX.展开更多
The Westinghouse Nuclear Safety Advisory Letter NSAL-09-8 investigated the possibility of presence of vapor in RHR （residual heat removal） system in modes 3/4 LOCA （loss-of-coolant accident） conditions. This conce...The Westinghouse Nuclear Safety Advisory Letter NSAL-09-8 investigated the possibility of presence of vapor in RHR （residual heat removal） system in modes 3/4 LOCA （loss-of-coolant accident） conditions. This concerns the Westinghouse standard three-loops plant for which the RHR is the low pressure part of the St （safety injection）. In some cases one or both RHR trains may become inoperable for SI function. As a response to this letter, Westinghouse Electric Belgium is providing RELAP5 analyzes for Westinghouse NSSS （nuclear steam supply system） European plants to assess the thermal hydraulic behavior of the RHR suction piping system for ECCS （emergency core cooling system） initiation events postulated to occur during startup/shutdown operations. Several concerns including condensation induced water hammer and voiding at the RHR pump have been investigated. As a conclusion, the analysis allowed to define the bounding hot leg temperature conditions under which both RHR trains remain safely operable. These bounding conditions are then implemented by the customer in their OPs （operating procedures） to achieve safe operations and successful accident management.展开更多
Passive residual heat removal heat exchanger(PRHR HX),which is a newly designed equipment in the advanced reactors of AP1000 and CAP1400,plays an important role in critical accidental conditions.The primary and second...Passive residual heat removal heat exchanger(PRHR HX),which is a newly designed equipment in the advanced reactors of AP1000 and CAP1400,plays an important role in critical accidental conditions.The primary and secondary side coupling heat transfer characteristics of the passive residual heat removal system(PRHRS)determine the capacity to remove core decay heat during the accidents.Therefore,it is necessary to investigate the heat transfer characteristics and develop applicable heat transfer formulas for optimized design.In the present paper,an overall scaled-down natural circulation loop of PRHRS in AP1000,which comprises a scaleddown in-containment refueling water storage tank(IRWST)and PRHR HX models and a simulator of the reactor core,is built to simulate the natural circulation process in residual heat removal accidents.A series of experiments are conducted to study thermal-hydraulic behaviors in both sides of the miniaturized PRHR HX which is simulated by 12 symmetric arranged C-shape tubes.For the local PRHR HX heat transfer performance,traditional natural convection correlations for both the horizontal and vertical bundles are compared with the experimental data to validate their applicability for the specific heat transfer condition.Moreover,the revised natural convection heat transfer correlations based on the present experimental data are developed for PRHR HX vertical and lower horizontal bundles.This paper provides essential references for the PRHRS operation and further optimized design.展开更多
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
文摘The technology of passive safety is the current trend among safety systems in nuclear power plant. Pas- sive residual heat removal system (PRHRS), a major part of passive safety systems of Chinese advanced PWR, is a novel design with three-fold natural circulation. On the basis of reasonable physics and mathematics models, MI- TAP-PRHRS code was developed to analyze steady and transient characteristics of the PRHRS. The calculation and analysis show that the code simulates steady characteristics of the PRHRS very well, and it is able to simulate tran- sient characteristics of all startup modes of the PRHRS. However, the quantitative description is poor during the ini- tial stages of the transition process when water hammer occurs.
文摘Three different kinds of experiments and their typical results are surveyed for the passive residual heat removal system (PRHRS) of PWR performed in Nuclear Power Institute of China (NPIC) recent ten years. The typi- cal results of MISAP, a special code for PWR passive residual heat removal system developed and assessed by NPIC, are also described briefly in this paper.
文摘Thermal-hydraulic characteristic investigation on passive residual heat removal system (PRHRS) of Chinese advanced PWR was conducted to provide input data for PRHRS design and to demonstrate the feasibility of unique design features. A total of 237 sets of test data at steady state have been obtained and the main influence factors on the two-phase natural circulation flow rate and residual heat removal capability were identified. On the basis of theory analysis, a correlation of two-phase natural circulation was obtained, and relative errors of 95% test data were less than ±16%. There is a considerable effect of the system status parameters on the threshold of height between heat source and heat sink, and its correlation of two-phase natural circulation system has been obtained. The steady characteristic research shows that PRHRS has the capability of removing the core decay power through natural circulation.
文摘The tube inside and outside heat transfer mechanism of Passive Residual Heat Removal Heat Exchanger (PRHR HX) was analyzed. The calculation method of this special heat exchanger under natural convection condition in In-containment Refueling Water Storage Tank (IRWST) was carried out. The single-tube coupling model three-dimensional natural circulation in the IRWST was simulated numerically using Fluent. The heat transfer and flow characteristics of the fluid in IRWST were obtained. The comparison of the results between theoretical arithmetic and numerical simulation showed that the theoretical calculation method is suitable for the heat transfer calculation of PRHR HX.
文摘The Westinghouse Nuclear Safety Advisory Letter NSAL-09-8 investigated the possibility of presence of vapor in RHR （residual heat removal） system in modes 3/4 LOCA （loss-of-coolant accident） conditions. This concerns the Westinghouse standard three-loops plant for which the RHR is the low pressure part of the St （safety injection）. In some cases one or both RHR trains may become inoperable for SI function. As a response to this letter, Westinghouse Electric Belgium is providing RELAP5 analyzes for Westinghouse NSSS （nuclear steam supply system） European plants to assess the thermal hydraulic behavior of the RHR suction piping system for ECCS （emergency core cooling system） initiation events postulated to occur during startup/shutdown operations. Several concerns including condensation induced water hammer and voiding at the RHR pump have been investigated. As a conclusion, the analysis allowed to define the bounding hot leg temperature conditions under which both RHR trains remain safely operable. These bounding conditions are then implemented by the customer in their OPs （operating procedures） to achieve safe operations and successful accident management.
基金the National Science and Technology Major Project of China(Grant No.2017ZX06004002-006-002)the National Natural Science Foundation of China(Grant No.51906069)。
文摘Passive residual heat removal heat exchanger(PRHR HX),which is a newly designed equipment in the advanced reactors of AP1000 and CAP1400,plays an important role in critical accidental conditions.The primary and secondary side coupling heat transfer characteristics of the passive residual heat removal system(PRHRS)determine the capacity to remove core decay heat during the accidents.Therefore,it is necessary to investigate the heat transfer characteristics and develop applicable heat transfer formulas for optimized design.In the present paper,an overall scaled-down natural circulation loop of PRHRS in AP1000,which comprises a scaleddown in-containment refueling water storage tank(IRWST)and PRHR HX models and a simulator of the reactor core,is built to simulate the natural circulation process in residual heat removal accidents.A series of experiments are conducted to study thermal-hydraulic behaviors in both sides of the miniaturized PRHR HX which is simulated by 12 symmetric arranged C-shape tubes.For the local PRHR HX heat transfer performance,traditional natural convection correlations for both the horizontal and vertical bundles are compared with the experimental data to validate their applicability for the specific heat transfer condition.Moreover,the revised natural convection heat transfer correlations based on the present experimental data are developed for PRHR HX vertical and lower horizontal bundles.This paper provides essential references for the PRHRS operation and further optimized design.
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。
