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     

钠冷快堆蒸汽发生器的模块化模型及瞬态仿真研究

研究了钠冷快堆电厂直管式直流蒸汽发生器可移动边界的模块化模型。采用ＭＡＴＬＡＢ语言,Ｃ语言编程与ＳＩＭＵＬＩＮＫ仿真工具相结合的建模方法,建立了仿真系统,对直管式直流蒸汽发生器的瞬态特性进行了研究,并获得了令人满意的结果。     

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Apros的套管式蒸汽发生器给水控制优化研究

针对套管式蒸汽发生器强耦合性造成的给水控制问题，以采用套管式蒸汽发生器的商用模块化小型反应堆汽水循环系统为研究对象，基于APROS软件建立汽水循环系统仿真模型。稳态仿真结果表明，仿真模型具有较高的仿真精度，满足仿真分析需求。通过升降负荷瞬态仿真试验，研究了套管式蒸汽发生器瞬态运行特性，研究结果表明，采用传统控制方案时，蒸汽流量和给水流量负荷跟随性较好，但蒸汽压力存在较大波动，且在功率由80%FP(FP为满功率)降至50%FP时会触发蒸汽排放。针对该问题提出了给水控制优化方案，仿真试验结果表明，优化后蒸汽压力波动范围明显降低，未触发蒸汽排放动作，系统安全性和稳定性得到了有效提升。     

负荷跟踪中直流蒸汽发生器的动态特性仿真计算

采用集中参数处理方法，把直流蒸气发生器二次侧按流体相变分区，建立了动态热工水力模型。同时该模型在相变交界面上可动边界，使模型更切合实际运行工况。计算表明，用这一处理方法，即满足了一定的精度要求，又缩减了计算时间，是直流蒸汽发生器的动态仿真和进行控制特性分析十分有效的方法。     

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.     

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。     

蒸汽排放系统蒸汽冷凝器动态特性仿真研究

根据核动力商船高压定压蒸汽冷凝器的结构及工作特性,建立了适合蒸汽冷凝器实时仿真分析计算的两相流仿真模型。利用该仿真模型对蒸汽冷凝器进行了稳态计算和动态仿真分析,并将其稳态计算结果与蒸汽冷凝器试验结果进行对比验证。结果表明：该模型能准确模拟蒸汽冷凝器的动态特性,满足核动力装置蒸汽排放系统实时仿真分析要求。研究结果对二回路系统启动及停运的运行和控制系统设计具有指导意义。     

模块式高温气冷堆核电站的运行特性研究

球床模块式高温气冷堆核电站(HTR-PM)由于具有多个模块，运行特性比单堆电站更复杂。利用集总参数方法建立了HTR-PM的动态模型，并利用该模型对电站的运行过程进行了仿真。升功率运行的仿真结果表明，蒸汽温度严重偏离了正常允许值。设计了1个基于蒸汽温度的简单控制器，仿真结果表明，该控制器能很好地对电站进行运行控制，结果令人满意。     

整体式预热器U型管蒸汽发生器数学模型及动态模拟

本文针对整体式预热器Ｕ型管蒸汽发生器建立了热工数学模型并进行了动态模拟。该模型是一个２５阶、非线性、可移动边界模型。包括：一、二次侧的质量与能量平衡方程以及确定二次侧下降段流量的动量守恒方程。对所建立的模型利用Ｇｅａｒ方法作了蒸汽阀门开度阶跃１０％的瞬态模拟，所得结果和国外所公布的结果吻合得很好。由此可见。本文所建立的模型可以为这种蒸汽发生器的设计、运行、控制提供理论依据。     

蒸汽发生器焊接堵管堵头的设计与评价

蒸汽发生器传热管是一回路承压边界中最薄弱的环节,当传热管发生严重降质时,通常采用堵管方式来避免二次侧流体受到放射污染。为克服现行堵管方法带来的高应力和塑性变形,或近程操作带来的人员受高剂量辐照问题,设计了一种新型蒸汽发生器自熔焊焊接堵管堵头,采用数值模拟方法进行了焊接残余应力研究和应力分析评价。结果表明该焊接堵管堵头是安全可靠的。     

Density Wave Instability in Once-Through Boiling Flow System, (II)

The density wave instability in a once-through boiling flow system is analyzed using a simplified model characterized by lumped parameters and moving boundaries. An analytical solution of the stability boundary is derived in generalized form, which is then verified by comparison with experimental data obtained in a joule-heated system. Further comparison with published data obtained from experiments with sodium-heated steam generator indicates that the proposed model can be validly used for preliminary estimation of the stability boundary. Several dimensionless parameters governing the stability are also derived from the proposed model.     

蒸汽发生器二次侧汽液两相流数值模拟

以大亚湾核电站蒸汽发生器为原型,在相似原理的指导下,建立了蒸汽发生器“单元管”三维物理模型,采用Particle模型和热力学相变模型,并基于CFX软件实现了蒸汽发生器二回路侧两相流流动与沸腾换热特性数值模拟。计算结果表明：满负荷运行时,沿传热管高度升高,蒸汽发生器的传热系数及截面含汽率均呈上升趋势,其平均传热系数的数值模拟结果与Rohsenow经验关联式计算结果间的误差为8.4%,出口质量含汽率与大亚湾核电站实际运行参数相符。热相变模型在蒸汽发生器两相流数值模拟中的成功应用,可为蒸汽发生器热工水力的准确分析提供参考。     

Restraining effect of support plates on the limit loads for circumferential cracks in the steam generator tube

The steam generator in a nuclear power plant is a large heat exchanger that uses heat from a reactor to generate steam to drive the turbine generator. Rupture of a steam generator tube can result in release of fission products to environment outside. Therefore, an accurate integrity assessment of the steam generator tubes with cracks is of great importance for maintaining the safety of a nuclear power plant. The steam generator tubes are supported at regular intervals by tube support plates and rotations of the tubes are restrained. Although it has been reported that the limit load for a circumferential crack is significantly affected by boundary condition of the tube, existing limit load solutions do not consider the restraining effect of tube support plate correctly. In addition, there are no limit load solutions for circumferential cracks in U-bend region with the effect of tube support plate. This paper provides detailed limit load solutions for circumferential cracks in top of tube sheet and the U-bend regions of the steam generator tube with the actual boundary conditions to simulate the restraining effect of the tube support plate. Such solutions are developed based on three-dimensional (3-D) finite element analyses. The resulting limit load solutions are given in a polynomial form, and thus can be simply used in practical integrity assessment of the steam generator tubes.     

蒸汽发生器二回路两相流模拟实验装置

由计算机控制的模拟实验台架,是根据压水堆核电站(主要针对秦山核电站)蒸汽发生器的热工参数设计的模拟蒸汽发生器二回路侧热工参数试验的实验台.它可以作为试验平台,用于蒸汽发生器缓蚀剂的动态试验和金属材料的腐蚀考验,促进各种新型缓蚀剂和金属材料在蒸汽发生器中的应用研究的开展.     

Determination of equivalent single crack based on coalescence criterion of collinear axial cracks

In a nuclear power plant the steam generator tubes cover a major portion of the primary pressure-retaining boundary. Thus, very conservative approaches have been taken in the light of steam generator tube integrity. According to the present criteria, tubes wall-thinned in excess of 40% should be plugged whatever the cause. However, many analytical and experimental results have shown that no safety problems exist even with thickness reductions greater than 40%. The present criterion was developed about 20 years ago when wear and pitting were dominant causes for steam generator tube degradation, and it is based on tubes with single cracks regardless of the fact that the appearance of multiple cracks is more common in general. The objective of this study is to review the conservatism of the present plugging criteria of steam generator tubes and to propose a new coalescence model for two adjacent through-wall cracks existing in steam generator tubes. Using the existing failure models and experimental results, we reviewed the conservatism of the present plugging criteria. In order to verify the usefulness of the proposed new coalescence model, we performed finite element analysis and some parametric studies. Then, we developed a coalescence evaluation diagram.