Influence of Circumferential Position of Guide Vane on Unsteady Flow Characteristics in Reactor Coolant Pump

2016 ◽  
Vol 52 (15) ◽  
pp. 197 ◽  
Author(s):  
Xiaorui CHENG
Keyword(s):  
Unsteady Flow ◽  
Guide Vane ◽  
Flow Characteristics ◽  
Coolant Pump ◽  
Reactor Coolant

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.

scholarly journals Effect of Suction and Discharge Conditions on the Unsteady Flow Phenomena of Axial-Flow Reactor Coolant Pump

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1592
Author(s):  
Xin Chen ◽  
Shiyang Li ◽  
Dazhuan Wu ◽  
Shuai Yang ◽  
Peng Wu
Keyword(s):  
Unsteady Flow ◽  
Pressure Pulsation ◽  
Flow Reactor ◽  
Axial Flow ◽  
Hydraulic Performance ◽  
Uniform Flow ◽  
Coolant Pump ◽  
Reactor Coolant ◽  
Flow Phenomena ◽  
Rotating Impeller

In order to study the effects of the suction and discharge conditions on the hydraulic performance and unsteady flow phenomena of an axial-flow reactor coolant pump (RCP), three RCP models with different suction and discharge configurations are analyzed by computational fluid dynamics (CFD) method. The CFD results are validated by experimental data. The hydraulic performance of the three RCP models shows little difference. However, the unsteady flow phenomena of RCP are significantly affected by the variation of suction and discharge conditions. Compared with that of Model E-S (baseline, elbow-single nozzle), the pressure pulsation in rotating frame of Model S-S (straight pipe-single nozzle) and Model E-D (elbow-double nozzles) is weakened in different degrees and forms, due to the more uniform flow fields upstream and downstream of the impeller, respectively. It indicates that the generalized rotor-stator interaction (RSI) actually exists between the rotating impeller and all stationary components causing the circumferentially non-uniform flow. Furthermore, improving the circumferential uniformity of the flow upstream and downstream of impeller (suction and discharge flow) also contributes to reducing the radial dynamic fluid force acting on the impeller. Compared with those of Model E-S, the dynamic FX and FY of Model S-S are severely weakened, and those of Model E-D also gain a minor amplitude decrease at fBPF. In contrast, the general pressure pulsation in fixed frame is mainly related to the rotating impeller and barely affected by the suction and discharge conditions.

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.

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.

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.

Flow Field Analysis of the Reactor Coolant Pump Internal Cooling Circulation

2017 ◽  
Author(s):  
Jie Qin ◽  
Qingmu Xu ◽  
Junkai Yuan ◽  
Kun Cai
Keyword(s):  
Heat Transfer ◽  
Flow Field ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Flow Distribution ◽  
Internal Cooling ◽  
Shaft Seal ◽  
Flow Area ◽  
Coolant Pump ◽  
Reactor Coolant

Reactor coolant pump (RCP) is one of the most critical devices in third generation of pressurized water reactor nuclear power plant. EMD shield pump and KSB wet winding pump are two representative kinds of RCPs without complex shaft seal system. Due to cancellation of shaft seal system, the entire rotors (including the flywheel) are immersed in the coolant. The losses in RCPs take one third of the total power including rotation loss caused by rotor in the water, electromagnetic loss in the shielding sleeve,the heat transferred through high temperature coolant, and heat generated by bearing.Because of the losses listed above, bearing and winding are heated,and the losses make temperature rise. in order to ensure that the motor is working properly at low temperatures, the company EMD and KSB design the RCP internal cooling circulation which brings the heat out to ensure the normal operation of the RCPs. The RCP internal cooling circulation includes inlet flow area, auxiliary impeller, thrust bearing, the lower flywheel, motor can, upper radial bearing, upper flywheel, outlet flow area, and external heat exchanger,etc. Flow characteristics in every flow path determine the flow distribution and heat transfer, and the flow distribution determines whether the cooling performance of RCP internal cooling circulation meets the requirements. In order to control operating temperature of motor and bearing, and to optimize heat transfer, adjusting the size of flow area and changing the flow characteristics arecritical. flow field and temperature field in RCP internal cooling circulation need overall analysis. Flow distribution can be obtained theoretically through the calculation of an overall three-dimensional model.But on the one hand, the calculation time is long due to a complex three-dimensional model with a large quantity of grids, on the other hand, it is easier to casue errors in local processing and the errors are difficult to find or correct. For rapid analysis and optimization of flow and heat transfer in RCP internal cooling circulation, ensure the motor winding and bearing operate at an appropriate temperature, the local characteristics of RCP internal cooling circulation are studied, one-dimensionalanalysis method of RCP internal cooling circulation is developed. This one-dimensional analysis method can be used to predict the flow distribution of each part of RCP internal cooling circulation according to change of the channel geometry parameters, key dimensions, boundary conditions and rotor speed. The geometric parameters are optimized by analyzing the flow distribution, and the purpose of design guidance are achieved.

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