# Study on Unsteady Flow Characteristics of Cooling Water Pump for Nuclear Power Plant Equipment under Low Flow Rate Conditions

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## Abstract

**:**

## 1. Introduction

## 2. Experimental System and Model Pump

#### 2.1. Experimental System

^{6}, and there are two sizes of dormitories that meet this requirement. However, based on the experimental requirements, we have selected an inlet pipe diameter of 350 mm and adopted the first scaling ratio.

#### 2.2. Mesh Generation

#### 2.3. Governing Equation and Turbulence Model

^{−4}and the wall surface is “No Slip Wall”. For weak separation levels and their inception, the recommended model is the k-ω-based shear stress transport (SST) standard model. Thus, this study applies the SST standard model.

#### 2.4. Boundary Conditions

## 3. Results and Discussions

#### 3.1. Pump Performance Analysis

#### 3.2. Analysis of Internal Flow in Suction Casing

#### 3.3. Analysis of Velocity Shape in the Impeller

#### 3.4. Blade Load Analysis

#### 3.5. Research on Unsteady Flow in Impeller

#### 3.6. Research on Impeller Pressure Pulsation and Internal Radial Force

## 4. Conclusions

## Author Contributions

## Funding

## Data Availability Statement

## Conflicts of Interest

## References

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**Figure 1.**Model pump and Experimental site diagram: (

**a**) Experimental site; (

**b**) Model pump internal structure.

**Figure 10.**Pressure cloud image and flow diagram on blade-to-blade plane of 0.5 span. #A–#D indicates the number of each vortex position; The yellow box shows the partial enlargement.

**Figure 13.**Streamwise velocity contour on the blade-to-blade plane of 0.5 span in different degrees: (

**a**) 0.6Q; (

**b**) 0.5Q; (

**c**) 0.4Q.

**Figure 16.**Frequency domain characteristics of the impeller with different flow rates and positions (

**a**) blade inlet; (

**b**) 0.5 times blade outlet; (

**c**) blade outlet.

Specific speed | n_{s} | 162 |

Design flow rate | Q_{opt} | 3400 m^{3}/h |

Rotating speed | n | 1480 r/min |

Diameter of impeller inlet | D_{1} | 324 mm |

Diameter of impeller outlet | D_{2} | 496 mm |

Number of impeller blades | Z | 7 |

Correlation Parameter | Prototype Pump | Model Pump | |||
---|---|---|---|---|---|

Scale | |||||

0.583 | 0.567 | 0.55 | 0.5 | ||

Inlet pipe diameter D (mm) | 600 | 350 | 340 | 330 | 300 |

Nominal diameter D_{2} (mm) | 486 | 283.5 | 275.4 | 267.3 | 243 |

Flow rate Q (m^{3}/h) | 3400 | 675 | 618 | 565 | 425 |

Head H (m) | 65 | 22.12 | 20.87 | 19.65 | 16.25 |

Circumferential velocity u (m/s) | 38.7 | 22.6 | 22.0 | 21.3 | 19.4 |

Reynolds number Re × 10^{6} | 20.12 | 6.85 | 6.46 | 6.08 | 5.03 |

Compliance with criteria (Yes/No) | Yes | Yes | Yes | No | No |

Component | Minimum Value | Maximum Value | Average Value |
---|---|---|---|

Impeller | 21.44 | 1375.81 | 690.50 |

Volute | 24.67 | 5342.50 | 2954.30 |

Suction casing | 17.74 | 5043.21 | 2621.40 |

Governing equation | Reynolds-averaged Navier-Stokes (RANS) |

Discretization | finite volume method (FVM) |

Advection scheme | high-resolution, second-order approximation |

Root mean square (RMS) residuals | below 1.0 × 10^{−4} |

Turbulence mode | k-ω-based shear stress transport (SST) standard |

Wall function | automatic with smooth and non-slip conditions |

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## Share and Cite

**MDPI and ACS Style**

Fu, Q.; Yang, D.; Zhang, J.; Zhu, R.; Shi, W.
Study on Unsteady Flow Characteristics of Cooling Water Pump for Nuclear Power Plant Equipment under Low Flow Rate Conditions. *Water* **2023**, *15*, 3780.
https://doi.org/10.3390/w15213780

**AMA Style**

Fu Q, Yang D, Zhang J, Zhu R, Shi W.
Study on Unsteady Flow Characteristics of Cooling Water Pump for Nuclear Power Plant Equipment under Low Flow Rate Conditions. *Water*. 2023; 15(21):3780.
https://doi.org/10.3390/w15213780

**Chicago/Turabian Style**

Fu, Qiang, Dawei Yang, Jilai Zhang, Rongsheng Zhu, and Wenhao Shi.
2023. "Study on Unsteady Flow Characteristics of Cooling Water Pump for Nuclear Power Plant Equipment under Low Flow Rate Conditions" *Water* 15, no. 21: 3780.
https://doi.org/10.3390/w15213780