Numerical Simulation of Structural Optimization for Inlet Pipe of Centrifugal Pump in Cap1400 Power Plant Auxiliary System

Abstract The centrifugal pump is the key equipment for power conversion in the CAP1400 power plant. According to the equipment layout requirements in the nuclear power plant process system design manual, the pipe section at the entrance should be a straight pipe with a length at least five times the pipe diameter. However, in actual layout, due to factors such as plant space or modularity, the layout of the inlet pipes of some centrifugal pumps cannot meet this requirement, resulting in non-uniform incoming flow at the pump inlet, which affects the safe and stable operation of the pump and system. In this paper, two different structures of rectifiers are designed and numerically simulated for the elbow part of the inlet pipe section of the SFS system centrifugal pump in the CAP1400 power plant. Firstly, the variation of flow uniformity of the pump inlet pipe at different inlet speeds is studied. Then, the influence of different structure rectifiers on the uniformity of flow at the pump inlet under the same working conditions is studied. The results show that the addition of a rectifier in the elbow can effectively improve the flow uniformity of the pump inlet section and reduce the effect of uneven inlet flow on the pump performance.

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Experiment and simulation about the effect of wear-ring abrasion on the performance of a marine centrifugal pump

Advances in Mechanical Engineering ◽

10.1177/1687814021998115 ◽

2021 ◽

Vol 13 (2) ◽

pp. 168781402199811

Author(s):

Wu Xianfang ◽

Du Xinlai ◽

Tan Minggao ◽

Liu Houlin

Keyword(s):

Numerical Simulation ◽

Centrifugal Pump ◽

Pressure Pulsation ◽

Vibration Velocity ◽

Test Results ◽

Obvious Effect ◽

Performance Change ◽

Pump Test ◽

Simulation Results ◽

Axis Passing

The wear-ring abrasion can cause performance degradation of the marine centrifugal pump. In order to study the effect of front and back wear-ring clearance on a pump, test and numerical simulation were used to investigate the performance change of a pump. The test results show that the head and efficiency of pump decrease by 3.56% and 9.62% respectively at 1.0 Qd due to the wear-ring abrasion. Under 1.0 Qd, with the increase of the front wear-ring the vibration velocity at pump foot increases from 0.4 mm/s to 1.0 mm/s. The axis passing frequency (APF) at the measuring points increases significantly and there appears new characteristic frequency of 3APF and 4APF. The numerical simulation results show that the front wear-ring abrasion affects the flow at the inlet of the front chamber of the pump and impeller passage. And the back wear-ring abrasion has obvious effect on the flow in the back chamber of the pump and impeller passage, while the multi-malfunction of the front wear-ring abrasion and back wear-ring abrasion has the most obvious effect on the flow velocity and flow stability inside pump. The pressure pulsation at Blade Passing Frequency (BPF) of the three schemes all decrease with the increase of the clearance.

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Numerical Simulation of Intrachamber Processes in the Power Plant

Applied Sciences ◽

10.3390/app11114990 ◽

2021 ◽

Vol 11 (11) ◽

pp. 4990

Author(s):

Boris Benderskiy ◽

Peter Frankovský ◽

Alena Chernova

Keyword(s):

Numerical Simulation ◽

Power Plant ◽

Flow Structure ◽

Power Plants ◽

Control Volume ◽

Conjugate Problem ◽

Topological Features ◽

Gas Dynamic ◽

Calculation Results ◽

Volume Method

This paper considers the issues of numerical modeling of nonstationary spatial gas dynamics in the pre-nozzle volume of the combustion chamber of a power plant with a cylindrical slot channel at the power plant of the mass supply surface. The numerical simulation for spatial objects is based on the solution conjugate problem of heat exchange by the control volume method in the open integrated platform for numerical simulation of continuum mechanics problems (openFoam). The calculation results for gas-dynamic and thermal processes in the power plant with a four-nozzle cover are presented. The analysis of gas-dynamic parameters and thermal flows near the nozzle cover, depending on the canal geometry, is given. The topological features of the flow structure and thermophysical parameters near the nozzle cap were studied. For the first time, the transformation of topological features of the flow structure in the pre-nozzle volume at changes in the mass channel’s geometry is revealed, described, and analyzed. The dependence of the Nusselt number in the central point of stagnation on the time of the power plants operation is revealed.

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Optimal Design of Slit Impeller for Low Specific Speed Centrifugal Pump Based on Orthogonal Test

Journal of Marine Science and Engineering ◽

10.3390/jmse9020121 ◽

2021 ◽

Vol 9 (2) ◽

pp. 121

Author(s):

Yang Yang ◽

Ling Zhou ◽

Hongtao Zhou ◽

Wanning Lv ◽

Jian Wang ◽

...

Keyword(s):

Numerical Simulation ◽

Centrifugal Pump ◽

Large Scale ◽

Internal Flow ◽

Orthogonal Test ◽

Centrifugal Pumps ◽

Initial Model ◽

Low Specific Speed ◽

Specific Speed ◽

Four Levels

Marine centrifugal pumps are mostly used on board ship, for transferring liquid from one point to another. Based on the combination of orthogonal testing and numerical simulation, this paper optimizes the structure of a drainage trough for a typical low-specific speed centrifugal pump, determines the priority of the various geometric factors of the drainage trough on the pump performance, and obtains the optimal impeller drainage trough scheme. The influence of drainage tank structure on the internal flow of a low-specific speed centrifugal pump is also analyzed. First, based on the experimental validation of the initial model, it is determined that the numerical simulation method used in this paper is highly accurate in predicting the performance of low-specific speed centrifugal pumps. Secondly, based on the three factors and four levels of the impeller drainage trough in the orthogonal test, the orthogonal test plan is determined and the orthogonal test results are analyzed. This work found that slit diameter and slit width have a large impact on the performance of low-specific speed centrifugal pumps, while long and short vane lap lengths have less impact. Finally, we compared the internal flow distribution between the initial model and the optimized model, and found that the slit structure could effectively reduce the pressure difference between the suction side and the pressure side of the blade. By weakening the large-scale vortex in the flow path and reducing the hydraulic losses, the drainage trough impellers obtained based on orthogonal tests can significantly improve the hydraulic efficiency of low-specific speed centrifugal pumps.

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