Transient Dynamic Characteristics Study on Reactor Coolant Pump in Variable Working Conditions

2012 ◽  
Vol 601 ◽  
pp. 258-264
Author(s):  
Rong Sheng Zhu ◽  
Xiu Li Wang ◽  
Yun Long ◽  
Zhi Jun Yu ◽  
Qiang Fu
Keyword(s):  
Guide Vane ◽  
Internal Flow ◽  
Radial Force ◽  
Fourth Quadrant ◽  
Pump Impeller ◽  
Coolant Pump ◽  
Guide Vanes ◽  
Reactor Coolant ◽  
Small Flow ◽  
Radial Forces

For the study of the transient hydraulic characteristics and internal flow mechanism of the reactor coolant pump from designed conditions to off-designed conditions, using CFX software to simulate the variable flow transient characteristics of reactor coolant pump impeller passageway. The results show that: during the flow transition, the radial force of the impeller doesn’t rotate around the coordinates origin, but rotates around some point in the fourth quadrant, and radial forces of the guide vanes mainly distributes in the first and second quadrant, and radial forces of the volute completely distribute in the fourth quadrant. Because of the influence from the blade number, radial forces of the impeller and guide vanes are in obvious star distribution, meanwhile, because the pump body uses annular structure，the flow and velocity in the impeller passageway and the pressure distribution of the impeller export asymmetry radial force. During the transition to big flow, the radial force impact of the impeller and guide vane mainly shows in the direction of the offset and slightly decreasement of the change magnitude. The radial force on the volute moves down with the incensement of the flow, and the changes magnitude become larger. During the transition to small flow, radial forces bearing on impellers, guide vanes and the volute, whether on the size, direction or the change magnitude, have a significant change.

Influence of Guide Vane Wrap Angle Key Design Parameters on Hydraulic Performance of Nuclear Reactor Coolant Pump

2014 ◽  
Vol 721 ◽  
pp. 73-77 ◽  
Author(s):  
Wei Nan Jin ◽  
Rong Xie ◽  
Mu Ting Hao ◽  
Xiao Fang Wang
Keyword(s):  
Flow Field ◽  
Nuclear Reactor ◽  
Guide Vane ◽  
Three Dimensional ◽  
Internal Flow ◽  
Hydraulic Performance ◽  
Design Parameters ◽  
Coolant Pump ◽  
Reactor Coolant ◽  
Wrap Angle

To study the effects of guide vane with different vane wrap angles and relative positions of outlet edge on hydraulic performance of nuclear reactor coolant pump, three-dimensional steady numerical simulations were performed by using CFD commercial software Numeca. The results show that the vane wrap angle changes the head and power characteristics by changing the relative velocity angle in vane outlet. The inner flow field changes while the wrap angle changes. With the wrap angle increases, the shock loss in volute is reducing, but the friction loss in vane passages is getting large. So there exists an optimum wrap angle and relative positions of outlet edge that corresponds to the highest efficiency of a pump. Numerical simulation is performed with the two key design parameters optimized through surrogate model, the internal flow field is improved and then the hydraulic efficiency is improved.

scholarly journals Influence of Circumferential Placement Position of Guide Vanes on Performance and Dynamic Characteristics of Nuclear Reactor Coolant Pump

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Xiaorui Cheng ◽  
Boru Lv ◽  
Chenying Ji ◽  
Ningning Jia ◽  
Dorah N
Keyword(s):  
Nuclear Reactor ◽  
Guide Vane ◽  
Equivalent Stress ◽  
Hydraulic Loss ◽  
Stress Strain ◽  
Coolant Pump ◽  
Guide Vanes ◽  
Reactor Coolant ◽  
Maximum Equivalent Stress ◽  
Exit Edge

In order to study the influence of the circumferential placement position of the guide vane on the flow field and stress-strain of a nuclear reactor coolant pump, the CAP1400 nuclear reactor coolant pump is taken as the research object. Based on numerical calculation and test results, the influence of circumferential placement position of the guide vane on the performance of the nuclear reactor coolant pump and stress-strain of guide vanes are analyzed by the unidirectional fluid-solid coupling method. The results show that the physical model and calculation method used in the study can accurately reflect the influence of the circumferential placement position of the guide vane on the nuclear reactor coolant pump. In the design condition, guide vane position has a great influence on the nuclear reactor coolant pump efficiency value, suction surface of the guide vane blade, and the maximum equivalent stress on the hub. However, it has a weak effect on the head value, pressure surface of the guide vane blade, and the maximum equivalent stress on the shroud. When the center line of the outlet diffuser channel of the case is located at the center of the outlet of flow channel of the guide vane, it is an optimal guide vane circumferential placement position, which can reduce the hydraulic loss of half of the case. Finally, it is found that the high stress concentration area is at the intersection of the exit edge of the vane blade and the front and rear cover, and the exit edge of the guide vane blade and its intersection with the front cover are areas where the strength damage is most likely to occur. This study provides a reference for nuclear reactor coolant pump installation, shock absorption design, and structural optimization.

scholarly journals Effect of eccentricity on radial force and cavitation characteristics in the reactor coolant pump

2020 ◽  
pp. 312-312
Author(s):  
Yuanyuan Zhao ◽  
Xiuli Wang ◽  
Rongsheng Zhu
Keyword(s):  
Nuclear Power ◽  
Nuclear Reactor ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Radial Force ◽  
Asymmetric Structure ◽  
Two Phase ◽  
Coolant Pump ◽  
Cavitation Inception ◽  
Reactor Coolant

Nuclear reactor coolant pump as one of the most critical equipment is the only one rotating equipment in first loop system of nuclear power plant. Due to the asymmetric structure of the pump body, especially the existence of outlet segment lead to a certain of radial force, the magnitude of radial force directly affects the work stability of the reactor coolant pump. The nuclear reactor coolant pump could stability work under those transient complex conditions is an important index of its performance. To study the cavitation characteristics and radial force of reactor coolant pump on transient cavitation, a prototype pump and those exhibiting different gravity center offsets are analyzed numerically with CFD software ANSYS CFX by employing RNG k-? model and two-fluid two-phase flow model. Through the experiment-combined simulation, the variations of cavitation characteristics and radial force of the reactor coolant pump under different eccentricities are characterized. As revealed from the results, the flow characteristics of the internal flow field of the nuclear main pump change after the axis is offset by different distance. The influence of eccentricity on the cavitation of the nuclear main pump is mainly manifested at the impeller inlet from cavitation inception to severe cavitation. When the eccentricity is 5mm, the cavitation performance is improved. The effect of eccentricity on the radial force of impeller is reflected in the variation of force direction. Compared with other plans, the radial force is superior in transient cavitation under the eccentricity of 5mm.

scholarly journals Mathematical Modelling Forecast on the Idling Transient Characteristic of Reactor Coolant Pump

Processes ◽  
2019 ◽  
Vol 7 (7) ◽  
pp. 452 ◽  
Author(s):  
Wang ◽  
Xie ◽  
Lu ◽  
Zhu ◽  
Fu ◽  
...  
Keyword(s):  
Transient Flow ◽  
Guide Vane ◽  
Characteristic Curve ◽  
Hydraulic Modeling ◽  
Modeling Framework ◽  
Coolant Pump ◽  
Important Indicator ◽  
Reactor Coolant ◽  
Power Failure ◽  
Accident Condition

The idling behavior of the reactor coolant pump is referred to as an important indicator of the safe operation of the nuclear power system, while the idling transition process under the power failure accident condition is developed as a transient flow process. In this process, the parameters such as the flow rate, speed, and head of the reactor coolant pump are all nonlinear changes. In order to ensure the optimal idling behavior of the reactor coolant pump under the power cutoff accident condition, this manuscript takes the guide vanes of the AP1000 reactor coolant pump as the subject of this study. In this paper, the mathematical model of idling speed and flow characteristic curve of reactor coolant pump under the power failure condition were proposed, while the hydraulic modeling database of different vane structure parameters was modeled based on the orthogonal optimization schemes. Furthermore, based on the mathematical modeling framework of multiple linear regressions, the mathematical relationship of the hydraulic performance of each guide vane in different parameters was predicted. The derived model was verified with the idling test data.

Study on pressure pulsation characteristics of reactor coolant pump during the idling transition process

2019 ◽  
Vol 25 (18) ◽  
pp. 2509-2522 ◽  
Author(s):  
Xiuli Wang ◽  
Yonggang Lu ◽  
Rongsheng Zhu ◽  
Yuanyuan Zhao ◽  
Qiang Fu
Keyword(s):  
Pressure Pulsation ◽  
Transient Flow ◽  
Guide Vane ◽  
Transition Process ◽  
Dynamics Simulation ◽  
Discrete Wavelet ◽  
Flow Process ◽  
Coolant Pump ◽  
Rotating Speed ◽  
Reactor Coolant

The idling characteristic of the reactor coolant pump is one of the important indicators for the safe operation of the nuclear power system. The idling transition process of the reactor coolant pump under the power failure accident condition belongs to the transient flow process. During most of the time of the idling transition process, the parameters of flow, rotating speed, and head are all nonlinear changes, and the study of the idling change law is extremely difficult. This paper introduces the nonlinear inertia transient phase of the reactor coolant pump and the principle of wavelet analysis. Based on the experimental results of the idling transition process, the polynomial fitting of the flow curve and the rotating speed curve is fitted, and the idling transient equation is established which is a boundary condition for computational fluid dynamics simulation of the nonlinear idling transient stage of the reactor coolant pump with different types of guide vanes. The signal fluctuation of pressure pulsation time-domain change at the volute outlet in different sub-bands is analyzed by means of a fast, discrete wavelet transform, and the effects of different vane optimizations in different idling stages are analyzed. It was found that the pressure fluctuation amplitude of each sub-frequency range of pump outlet in the model of the shunt guide vane is significantly smaller than that of the normal guide vane.

Study on the transient evolution law of internal flow field and dynamic stress of reactor coolant pump under rotor seizure accident

2019 ◽  
Vol 133 ◽  
pp. 35-45
Author(s):  
Xiuli Wang ◽  
Yonggang Lu ◽  
Rongsheng Zhu ◽  
Qiang Fu ◽  
Yiming Chen ◽  
...  
Keyword(s):  
Flow Field ◽  
Dynamic Stress ◽  
Internal Flow ◽  
Coolant Pump ◽  
Evolution Law ◽  
Reactor Coolant

Numerical Simulation of Interior Flow Field of Reactor Coolant Pump under Station Blackout Accident

2012 ◽  
Vol 455-456 ◽  
pp. 1002-1008 ◽  
Author(s):  
Yi Ming Xu ◽  
Shi Ming Xu
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Internal Flow ◽  
Simulation Method ◽  
Governing Equations ◽  
Coolant Pump ◽  
Reactor Coolant ◽  
Internal Characteristic ◽  
Station Blackout ◽  
Interior Flow

Numerical simulation is used for researching the transient characteristic and internal characteristic of the reactor coolant pump under station blackout accident. The simulation method has been presented by analyzing difference scheme for governing equations. The analytical model of reactor coolant pump flow field has been established by analyzing adequately the influence of varying rotation speed to the pump external characteristic. Finally, the pump internal flow characteristic is exposed.

Paper 10: Radial Forces in Centrifugal Pumps with Guide Vanes

1969 ◽  
Vol 184 (14) ◽  
pp. 101-107 ◽  
Author(s):  
P. Hergt ◽  
P. Krieger
Keyword(s):  
Pressure Distribution ◽  
Shallow Water ◽  
Experimental Test ◽  
Centrifugal Pumps ◽  
Test Rig ◽  
Guide Vanes ◽  
Water Test ◽  
Small Flow ◽  
Radial Forces ◽  
Load Conditions

At partial and overload conditions, radial decentralizing forces act upon the rotor of a centrifugal pump with guide vanes if the impeller is out of centre. The magnitude of these forces depends on load conditions, and the forces increase with growing eccentricity. At very small flow, these forces become non-stationary. They rotate at a considerably lower frequency than the velocity frequency and may lead to rotor vibrations. The paper discusses the effects of stationary and non-stationary radial forces, and resulting shaft deflections and vibrations, from measurements on two experimental test rigs. The paper also presents the results of research on the pressure distribution of guide vanes, carried out in air, and gives observations of flow patterns in a shallow water test rig.

scholarly journals Analysis of Pressure Pulsation Induced by Rotor-Stator Interaction in Nuclear Reactor Coolant Pump

2017 ◽  
Vol 2017 ◽  
pp. 1-18 ◽  
Author(s):  
Xu Zhang ◽  
Pengfei Wang ◽  
Xiaodong Ruan ◽  
Zhongbin Xu ◽  
Xin Fu
Keyword(s):  
Flow Rate ◽  
Pressure Pulsation ◽  
Operating Conditions ◽  
Impeller Blade ◽  
Coolant Pump ◽  
Guide Vanes ◽  
Rate Distribution ◽  
Reactor Coolant ◽  
Rotor Stator Interaction ◽  
Phase Differences

The internal flow of reactor coolant pump (RCP) is much more complex than the flow of a general mixed-flow pump due to high temperature, high pressure, and large flow rate. The pressure pulsation that is induced by rotor-stator interaction (RSI) has significant effects on the performance of pump; therefore, it is necessary to figure out the distribution and propagation characteristics of pressure pulsation in the pump. The study uses CFD method to calculate the behavior of the flow. Results show that the amplitudes of pressure pulsation get the maximum between the rotor and stator, and the dissipation rate of pressure pulsation in impellers passage is larger than that in guide vanes passage. The behavior is associated with the frequency of pressure wave in different regions. The flow rate distribution is influenced by the operating conditions. The study finds that, at nominal flow, the flow rate distribution in guide vanes is relatively uniform and the pressure pulsation amplitude is the smallest. Besides, the vortex shedding or backflow from the impeller blade exit has the same frequency as pressure pulsation but there are phase differences, and it has been confirmed that the absolute value of phase differences reflects the vorticity intensity.

scholarly journals Experimental and Numerical Investigation of Radial Forces Acting on Centrifugal Pump Impeller

2014 ◽  
Vol 61 (3) ◽  
pp. 445-454 ◽  
Author(s):  
Krzysztof Karaskiewicz ◽  
Marek Szlaga
Keyword(s):  
Centrifugal Pump ◽  
Rectangular Cross Section ◽  
Radial Force ◽  
Axial Thrust ◽  
Pump Impeller ◽  
Ansys Fluent ◽  
Commercial Code ◽  
Radial Forces ◽  
Radial Thrust ◽  
Centrifugal Pump Impeller

Abstract The paper presents the results of measurements and predictions of radial thrust in centrifugal pump with specific speed ns = 26. In the pump tested, a volute with rectangular cross-section was used. The tests were carried out for several rotational speeds, including speeds above and below the nominal one. Commercial code ANSYS Fluent was used for the calculations. Apart from the predictions of the radial force, the calculations of axial thrust were also conducted, and correlation between thrust and the radial force was found. In the range of the measured rotational speeds, similarity of radial forces was checked.

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