登录

双语推荐:核主泵

针对突发断电事故下的核主泵惰转工况,基于额定参数提出惰转转速与惰转流量特性曲线计算模型,并通过100D型核主泵惰转试验数据对推导的模型予以验证。结果表明,该计算模型可用于核主泵初步设计计算和验证分析。基于该模型进一步得到了核主泵惰转设计准则,并验证了AP1000核主泵设计转动惯量。
For a sudden loss of power in reactor coolant pump (RCP) ,a calculation model of rotor speed and flow characteristics based on rated parameters was studied . The derived model was verified by comparing with the power-off experimental data of 100D RCP .T he results indicate that it can be used in preliminary design calculation and verification analysis .Then a design criterion of RCP was described based on the calcula-tion model .The moment of inertia in AP1000 RCP was verified by this criterion .

[ 可能符合您检索需要的词汇 ]

为研究小流量工况下核主泵内部压力脉动的变化规律,基于雷诺时均N—S方程和标准k—ε两方程及SIMPLEC算法,应用CFX软件对核主泵小流量工况进行定常和非定常数值计算,得到内部流场和各工况监测点的压力脉动,并将时域信号进行快速傅里叶变换为频域信号。结果表明:核主泵内压力脉动明显,叶频在由压力脉动诱发的振动中起导作用,要表现为叶轮和导叶间的动静干涉。叶轮导叶流道内的回流造成了小流量工况叶轮和导叶流道及其周向的不稳定压力脉动,回流要存在于叶轮和导叶进出口位置,因此该区域的压力波动剧烈且周期性差。核主泵的振动,不利于电站的安全稳定运行,通过对小流量工况的压力脉动分析,对预测核主泵在极端工况下的动态特性和推进核主泵国产化具有十分重要的意义。
In order to study pressure pulsation of a reactor coolant pump under low flow conditions,based on Reynolds-averaged Navier-Stokes equations with a standard k-εturbulence model and SIMPLEC algorithm,using the computational fluid dynamics software CFX to do numerical simulation calculations,the flow field insider the pump and pressure pulsations of monitored points under various working conditions were obtained.Fast Fourier Transformation(FFT) was used to transform time-domain pressure signals into frequency-domain pressure ones.The results showed that pressure pulsation in a reactor coolant pump is obvious;the blade frequency plays a dominant role in the vibration induced by the pressure pulsation,dynamic-static interference between the impeller and guide vane anifests itself;the reflow in the impeller diffuser flow channel leads to the unsteady pressure pulsations of the impeller diffuser flow channel and its circumferential direction under low flow conditions;the reflow of

[ 可能符合您检索需要的词汇 ]

针对电站冷却剂故障特征微弱难以有效辨识及DST仅能解决在无高冲突辨识框架下的单一故障诊断等问题,提出一种基于DSmT决策级冷却剂并发故障融合诊断模型.采用核主泵自由DSm模型和混合DSm模型对含有故障信息的多个独立证据源进行动态融合计算;分析核主泵DSmT故障特征信度赋值变化,确定冷却剂故障(并发故障)诊断总决策.结果表明,将仿真机采集TS、SS、VS和DS多源传感器数据直接对基本概率函数进行赋值,得出冷却剂故障(并发故障)决策结果与实际工况相符,实例验证了所提方法的可行性、有效性及准确性.
Aiming at the problems that the faults of NPP ’ s main coolant pump are difficult to recognize effectively during their early phases, and that DST can only solve single fault diagnosis in the identification framework without serious conflict, this paper proposes a diagnosis model for main coolant pump’ s concurrent fault fusion in early phases, based on DSmT. Taking advantage of DSmT, multiple independent proofs are used to conduct fusion decision, and obtain the results of main pump fault and concurrent fault diagnosis. On the simulation machine of nuclear power plant, main coolant pump was simulated and verified, and the results show that this method can improve the accuracy of recognition of main pump ’ s current faults during early phases, and reduce the uncertainty of the diagnosis.

[ 可能符合您检索需要的词汇 ]

结合AP1000电厂对主泵变频器的特殊要求,深入剖析AP1000主泵变频器的设计要点、系统组成、工作机理及实现可靠性提升的一些关键措施。
This thesis thoroughly expound the key design points, system configuration, operating principle as well as the critical measures to improve the reliability of the RCP VFD system for the special requirements of RCP VFD by AP1000 NPP.

[ 可能符合您检索需要的词汇 ]

为研究核主泵模型导叶非均布对于其外特性及压力脉动影响,分别采用SST(剪切应力输运) k-ω湍流模型和分离涡模拟方法对内部流场进行了三维定常和非定常数值模拟,得到两模型外特性曲线和内部压力脉动情况,并对压力脉动进行时域频域分析。结果表明:采用特定形式的非均布导叶可以改善出口流动,提升模型多工况性能;导叶非均布对于内不同区域压力脉动影响不同,但其改变了由动静干涉产生的脉动频率分布,削弱了脉动幅值,有助于降低的振动和噪声,提高核主泵的安全性。
The shear stress transport ( SST) k-ωturbulent models and detached eddy simulations were used in steady and un-steady 3-dimensional numerical simulation to investigate the influence of uneven guide blade on performance and pressure fluctua-tion of nuclear model pump. Two model''s performance curves and pressure fluctuation were gotten,and both time and frequency domain of pressure fluctuation were analyzed. It is shown that,the flow condition at the outlet is improved with a specific configu-ration of uneven guide blade,and the performance of multiple operating conditions is promoted. Effects of uneven guide blade on pressure fluctuation in different area of model pump are of their own features. But the frequency and amplitude which Caused by rotor-stator interaction are changed and decreased. It helps to reduce the vibration and noise,improve the safety of nuclear main pump.

[ 可能符合您检索需要的词汇 ]

为了研究屏蔽式核主泵动静转子间的压力脉动特征,应用数值模拟方法,采用分离涡模拟(DES ),对模型不同流量工况进行非定常计算,分析其时域特征和频域特征,得到了其压力脉动特性。结果表明:核主泵模型动静转子之间压力脉动的频率为叶频及其倍频,这是由于叶轮出口边的射流尾迹与导叶入口边周期性的相互切割作用引起的。压力脉动的波动幅度在蜗壳出口处最大,且沿逆时针方向逐渐减弱;在小流量下较小,随着流量增大,其波动幅度增大。动静转子间存在低压流体区域,其数量与叶轮叶片数相同,传播速度与叶轮转速相同。
The characteristics of pressure fluctuation between the rotor and stator in the model pump of canned nuclear coolant pump were researched .The time domain and fre-quency domain of pressure fluctuation were obtained with CFD method and a detached eddy simulation (DES) method .The results show that the pressure fluctuation between the rotor and stator is dominated by the blade passing frequency ,and it is due to the jet wake of the impeller’s trailing edges periodically cutting the guide vane’s leading edges . T he amplitude of the pressure fluctuation of the outlet position reaches the maximum , and the amplitude of the pressure fluctuation decreases along the counterclockwise direc-tion .T he amplitude of the pressure fluctuation is small under low flow rate ,and the volatility of pressure fluctuation is larger with the flow rate becomes larger .There are some low pressure regions between the rotor and stator ,and the low pressure region propagates at the impeller rotational speed .

[ 可能符合您检索需要的词汇 ]

采用流场分析软件ANSYS CFX对核主泵在不同空化工况下的水动力特性进行数值模拟分析,利用Morlet小波变换和快速傅里叶变换对相应数据进行处理分析。结果表明:气体含量随压力的降低或时间的增加呈现出指数变化规律。在空化初生工况,核主泵扬程脉动频率以低频为,叶轮流道内的压力脉动的频仍以转频为,而空化产生的压力脉动对频的影响不明显。随着空化的发展,空化所诱发的压力脉动对频、次频及脉动幅值的影响越来越大,其扬程脉动频率以低频脉动为。空化严重工况时,扬程脉动频率以无规律变化的脉动高频为,同时包含近乎规律变化的脉动低频。
T he reactor coolant pump hydrodynamic characteristics at different cavitation conditions were studied by using flow field analysis software ANSYS CFX ,and the cor-responding data were processed and analyzed by using Morlet wavelet transform and fast Fourier transform .The results show that gas content presents the law of exponential function with the pressure reduction or time increase . In the cavitation primary condition ,the pulsation frequency of head for the reactor coolant pump is mainly low frequency ,and the main frequency of pressure pulsation is still rotation frequency w hile the effect of the pressure pulsation caused by cavitation on main frequency is not obvi-ous .With the development of cavitation ,the pressure fluctuation induced by cavitation becomes more serious especially for the main frequency ,secondary frequency and pulsa-ting amplitude w hile the head pulsation frequency is given priority to low frequency pulse .Under serious cavitation condition ,the head pulsa

[ 可能符合您检索需要的词汇 ]

电厂仪表系统功率量程中子注量率变化率是反应堆保护系统的重要参数,对该参数的计算校准,既可以保证在发生弹棒和落棒事故时正常执行停堆功能,又可以在寿期初和寿期末发生甩负荷至厂用电运行工况时避免停堆而影响电厂的经济性。当前电厂,仪表系统功率量程中子注量率变化率引入的回路平均温度信号和主泵转速信号进行校准。本文着重介绍一种采用精确的反应堆冷却剂系统回路流量来校准中子注量率变化率的方法,对其进行研究与探讨,以达到提高功率量程中子注量率变化率的校准精度的目的。
The change rate of neutron flux in nuclear power plant (NPP)nuclear instrumentation system is an important protection parameter. Calibration of the parameter can ensure the normal reactor shutdown function when rod drop and rod eject accident occurred, and can avoid affect the economy of NPP via reactor trip on the condition of load shedding on the beginning and the ending of the life time. In current NPP, the change rate of neutron flux is calibrated according to the primary loop average temperature signals and reactor coolant pump speed signals. This article highlights one change rate of neutron flux calibration method according to the accurate primary loop flow of reactor coolant system, so as to improve the calibration accuracy of the change rate of neutron flux.
为研究核主泵在变流量过渡过程中叶片数与导叶片数对径向力的影响,应用计算流体力学软件CFX对核主泵分别改变叶片数与导叶片数时,叶轮与导叶所承受的径向力变化规律进行数值模拟计算与试验,将数值模拟结果与试验进行验证,试验数据与数值模拟数据在误差控制范围之内。结果表明:变叶片数时,随着流量增大,核主泵叶轮所承受的径向力值随叶片数的增加而增大,在叶片数为7片时达到最大值,叶轮所承受的径向力的周期性趋于规律性;径向力的平衡性趋于最佳工况。随流量变小时,叶轮所承受的径向力位置随旋转周期有规律性地偏移和旋转,其偏移和旋转的变化梯度不同,叶轮所承受的径向力偏移和旋转的变化梯度明显大于向大流量增加时所对应的变化梯度。通过综合对比可知:在变流量过程中,当叶片数为5片、导叶片为11片时,叶轮承受的径向力是最小。
To study the effect of number of blades and guide vanes on a reactor coolant pump’s radial force under variable flow transition conditions,the computational fluid dynamics software CFX was applied in the numerical simulation and test for the radial force variation law with number of blades or guide vanes changed.Compared the numerical simulation results with the experimental ones,both of them were within the error control range.The results showed that with flow rate increasing,the radial force of the reactor coolant pump impeller increases with increase in number of blades,and reaches the maximum value with the blade number of 7,the periodicity of the radial force tends to regularity, the radial force balance tends to the optimum working condition;with flow rate decreasing,the position of the impeller radial force offsets and rotates regularly in its rotating cycle,and the variation gradients of offset and rotation are different;the variation gradients of the impeller radial

[ 可能符合您检索需要的词汇 ]

采用基础水力设计方法,利用模型叶轮外参数设计AP1000核主泵直导叶;基于CFD的数值计算与分析结果,针对所设计的直导叶内部流场流动损失较大的问题,提出2种不同的优化设计方案:第1种直接在直导叶的基础上进行优化设计;第2种采用叶轮与导叶配合设计的方法,将直导叶转化为扭曲空间导叶,并对其进行优化.在空间导叶的优化中也考虑了2种方案,对叶型进行参数化造型,然后生成样本数据库,选择叶轮加导叶结构的水力效率作为优化的目标函数,利用人工神经网络和遗传算法对不同空间导叶叶型进行多次优化改进,最终获得与叶轮水力性能匹配优良的核主泵导叶.最后讨论了不同导叶叶片数对水力效率的影响,从流动的角度对导叶叶片数的选取提供了理论指导和参考.
Based on self-design of impeller of AP1000 nuclear main pump,the upright guide vane was designed using foundational hydraulic methods.In order to reduce the hydraulic loss in the vane flow passage,two different schemes were proposed to optimize the vane design after analyzing the CFD com-putational results.The first one was to directly optimize the upright guide vanes design.And the other was to redesign the upright guide vanes as twisted spatial type to match up the impeller and subse-quently to optimize the vanes.In the space guide vanes design and optimization process,two different solutions were adopted to parameterize the model,and the sample database were generated.With the hydraulic efficiency of impeller and guide vane being selected as the optimization objective,ANN and genetic algorithms were used to repeatedly optimize the blade profile of space guide vanes,and finally the guide vanes were obtained with better hydraulic efficiency matching with the impeller.The inf

[ 可能符合您检索需要的词汇 ]