新型圻流蒸汽发生器的稳态特性分析

新型直流蒸汽发生器采用双南传热的双层套管结构，一次侧的单相流体分别在内、外侧强迫流动，二次侧经过相变的流体逆向强迫流动，根据这些特点，建立了稳态热工流体模型。该模型考虑了不同运行工况的流体流动及伟热特性，因而可满足整个运行范围内的稳态分析，可为动态计算及不稳定性分析提供初始条件。计算表明，所建模型是很好的稳态分析模型，计算精度满足工程实际要求。     

螺旋管式直流蒸汽发生器的集总参数动态模型

基于基本的流体质量、能量和动量守恒原理，建立了10MW高温气冷堆螺旋管式直流蒸汽发生器的动态数学模型。模型采用了集总参数的建模方法，将蒸汽发生器作为单管模型处理，分为热水段、蒸发段和过热段，且各段间具有可移动的边界。对建立的模型进行了静态和动态仿真，仿真结果表明，所建立的模型是正确和有效的，能够用来进行蒸汽发生器的动态特性仿真。     

固定边界与移动边界直流蒸汽发生器模型的比较

介绍了一种直流蒸汽发生器的可移动边界模型。该模型按流体相的不同把蒸汽发生器划分为过冷区、两相区和过热区 3个部分。利用该模型编制了直流蒸汽发生器的瞬态热工水力分析程序。编制了固定边界模型的仿真程序。与试验数据及固定边界模型计算结果比较 ,表明可移动边界模型同时具有计算速度快和精度高的特点 ,是直流蒸汽发生器动态仿真的一种比较理想的模型     

套管式直流蒸汽发生器动态实时仿真研究

基于基本的流体质量、能量和动量守恒原理,建立了套管式直流蒸汽发生器的动态数学模型。该模型采用集总参数和移动边界的建模方法,将直流蒸汽发生器流道分为欠热段、沸腾段和过热段。采用Gear算法求解,对建立的模型进行稳态和动态仿真,并利用RELAP程序进行校验。结果表明：所建立的模型是正确和有效的,能用来进行直流蒸汽发生器的动态特性实时仿真。     

基于RELAP5程序的直管式直流蒸汽发生器敏感性分析

直流蒸汽发生器内二回路侧的工质水经历了复杂的相变过程,流型转变和传热情况比自然循环式蒸汽发生器要复杂。本文以B&W公司的19管直管式直流蒸汽发生器实验装置为研究对象,采用最佳估算程序RELAP5/MOD3.4对其进行建模分析,研究了节点划分个数、计算时间步长、不同算法和分析方法对计算结果的影响,研究了系统程序RELAP5在分析存在有剧烈相变问题时需注意的不确定性因素。结果表明：应适当增加控制体的划分个数、降低计算时间步长;注意两相流模型的选择使用;注意两种算法的使用场合;同时应选择多通道的分析方法。     

螺旋管式直流蒸汽发生器热工水力分析模型

基于混合流模型的质量、动量和能量守恒方程,采用可移动边界法建立了压水堆螺旋管式直流蒸汽发生器的稳态和动态分析模型。模型将二次侧传热区域分为预热段、蒸发段和过热段,且考虑了缺液区传热。通过对国际革新与安全反应堆(IRIS)螺旋管式直流蒸汽发生器的模拟,对模型进行了验证。结果表明,本文所建立的稳态和动态模型合理,稳态计算结果与设计值符合良好,动态仿真符合热工水力学及其定性机理分析结果。     

套管式双面加热蒸汽发生器的热工水力分析

为研究套管式双面加热蒸汽发生器在稳态和瞬态过程中的热工水力特性，建立了描述蒸汽发生器物理现象的一维均匀流数学模型。应用该模型，开发了可计算稳态和瞬态工况下一回路和二回路冷却剂温度场、焓场的直流蒸汽发生器热工水力程序。计算结果对直流蒸汽发生器结构设计、运行具有指导意义。      

核动力装置蒸汽发生器数值模拟计算

建立了一个合理完善的核动力装置蒸汽发生器动态特性分析数学模型，并运用Ｇｅａｒ方法对此模型求解。研制了用于核动力装置蒸汽发生器稳定运行及扰动和事故工况下动态数值模拟的安全分析程序。运用此程序对秦山核电厂蒸汽发生器失去给水的事故进行了计算，所得结果与大型程序ＲＥＬＡＰ－５计算结果符合较好，并对蒸汽发生器几种不同扰动序列的计算结果进行了理论分析。     

套管式直流蒸汽发生器动态特性仿真研究

套管式直流蒸汽发生器是一种采用双面传热的新型蒸汽发生器.在中心管和环管外侧与环形通道流体间热流密度相等的假设基础上,合理选择集中参数并应用可动边界的处理方法对套管式直流蒸汽发生器传热管进行了动态仿真.仿真结果与热工水力定性机理分析结果及相关的试验结果相符,从而验证了仿真方法是有效的.     

两相流模型在直流蒸汽发生器热工水力分析中的比较研究

根据组成气液两相流基本场方程数量所反映的流动与传热特性的不同,两相流方程分为三方程、四方程、五方程和六方程模型,结合流动压降模型、传热模型、两相相互作用模型以及流动工质的状态参数和结构材料热物性等辅助关系式,可很好地对蒸汽产生系统进行设计和研究分析。本文分析了不同数量的两相流场方程的特点和局限性,结合直管式直流蒸汽发生器实验装置,分别选取最佳估算程序中4种不同的两相流场方程计算模型进行流动传热计算分析,重点比较了强制流动的单相过冷水被加热至单相过热蒸汽过程中的压力与传热特性,从而给出不同场方程的两相流模型在分析具有较大相变过程中的差异性,验证了RELAP5程序和RETRAN-3D程序计算分析直流蒸汽发生器的能力。结果表明,RELAP5程序的六方程模型更适合模拟直流蒸汽发生器。     

套管式直流蒸发器的建模及仿真

针对新型直流蒸发器采用的双面传热的双层竖直套管结构,建立动态数学模型.该模型考虑了不同运行工况的流体流动及传热特性,可满足整个运行范围内的稳态和动态分析,为控制系统的设计、操作、异常工况和故障的分析与处理,运行规程的编制等均能提供必要的依据.     

可连续移动相边界的直流式蒸汽发生器模型

以全微分公式为数学基础,提出了可连续移动相边界的直流式蒸汽发生器模型。为了改善值求解稳定性,在用状态变量的空间差分来逼近空间导数时,根据不同情况采用前向差分或后向差分。根据该模型编制的程序对ＯＴＳＧ的动态进行仿真,取得了很好的仿真效果。     

Numerical study on effect of gap width of narrow rectangular channel on critical heat flux enhancement

According to the flow passage characteristic of narrow rectangular channel and liquid film dry-out mechanics of annular flow critical heat flux (CHF), an annular flow CHF analytical model for narrow rectangular channel has been achieved. This model may be used to predict the CHF behavior of boiling two-phase flow in narrow rectangular channel with gap width of not being less than 0.0005 m (the equivalent diameter of this channel is 0.001 m). Through analyzing and calculating, when the inlet dimensionless gap width of narrow rectangular channel is within 30-85, the enhancement of CHF in channel is obvious. At the same time, according to the characteristic of two-phase flow, the new determinant laws of CHF in boiling two-phase flow system have been derived. Through analyzing and calculating, it is substantial that this determinant laws is appropriate. The best dimensionless gap width of heat flux enhancement has been achieved to be 45-75.     

高通量工程试验堆燃料元件热工水力特性计算

从基本的质量、动量、能量守恒方程出发,建立了合理的高通量工程试验堆多层套管元件的热工水力特性分析计算模型,并运用在此模型基础上开发的计算程序对高通量工程试验堆燃料元件的运行工况进行了分析计算,计算结果与理论分析以及高通量工程试验堆实际运行结果相符.     

A simple forced diversion model for study of thermal-hydraulic transients in LMFBR subassembly

The generalized simple, transient, integral energy balances based on the average properties for the fuel and cladding have been used in our new multichannel thermal-hydraulic model for calculating the transient behavior of coolant in the rod bundle. This model was developed to provide a simple useful tool for analyzing the flow and thermal transients in a rod bundle with reasonable accuracy, and to understand the fundamental characteristics of flow in the rod bundle under both normal and abnormal condition of reactor-core operation.     

Ex-vessel molten core solidification behavior by moving particle semi-implicit method

Development of analysis code for predicting the molten core solidification behavior during the severe accident in nuclear power plants is necessary. Although agreeable results have been achieved using existing codes such as CORFLOW and LAVA to analyze some melt spreading experiments, these codes have a common problem of versatility because they all use empirical equations such as mass flux depending on distance from wall to calculate free surface of fluid. Moving particle semi-implicit (MPS) method which calculates free surface without empirical equations is suitable for analyzing the solidification behavior of fluid with large deformation. In this work, the MPS code for incompressible fluid was developed for calculating thermal field, solid-liquid phase transition, and temperature dependence of viscosity. Based on the MPS model, the FARO-L26S core melt solidification experiment was analyzed. For the leading edge position of the melt in this experiment, three-dimensional MPS simulations predicted agreeable multistage curve results with the experiment.     

BWR stability boundary surveillance

Neutron noise analysis can make great contributions in order to prevent the power instability event during the reactor starting up process. There is not reason to suppose that the stability boundary in the operation map, cannot drift away getting closer to the real operation point. Noise analysis can perform a double eye boundary drift surveillance by fitting the noise time series to an autoregressive model, and calculating the complex and the real pole. The complex pole accounts for the Decay Ratio and the real pole confirms this accounting. The real pole has a hidden relation with the chaotic behavior of the power, and it is related with the bubble residence time. In case of instability, the real pole vanishes.     

Multi-Channel Thermal Hydraulic Model for LOCA Analysis of Heterogeneous BWR Core

A multi-channel thermal hydraulic model for LOCA analysis of a heterogeneous core such as a HCBWR has been developed. This model solves integral formulations for basic equations based on a one-dimensional drift flux model. The core region is divided into several fuel channel groups which differ in their thermal power or geometry. The various flow patterns in the core are determined by calculating the redistribution of vapor generated in the lower plenum into the fuel channel groups. In order to verify the multi-channel model, a computer program FLORA was developed based on the multi-channel model and large and small break LOCA experiments conducted in the Two Bundle Loop (TBL) facility were analyzed by the FLORA program. As a result, the difference in thermal hydraulic behavior between two bundles with different power in the various break LOCA experiments were well simulated.     

LOCA事故下安全注射系统可靠性的GO-FLOW法分析

反应堆安全注射系统是包含复杂操作时序的动态系统,本文研究了应用GO-FLOW方法对其进行可靠性分析,导出了能将GO-FLOW用于含两种失效模式的可修部件状态概率计算的可靠性参数等效模型,并验证了模型的正确性。给出了实际算例,结果表明,GO-FLOW方法是对含时序问题的动态系统进行可靠性分析的有效工具,本文导出的可靠性参数等效模型提高了GO-FLOW对多状态问题的分析能力。     

束流传输的优化计算程序——NISTS

本文描述了束流传输优化设计的数学模型和最优化计算方法;介绍了本优化计算程序的功能、特点和作者的计算经验;给出了计算实例。