# Energy Saving in a Water Supply Network by Coupling a Pump and a Pump As Turbine (PAT) in a Turbopump

^{1}

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## Abstract

**:**

## 1. Introduction

## 2. State-of-the-Art

#### 2.1. Machine Behaviour

#### 2.2. Energy Recovery in Water Systems

## 3. Pump and PAT Characteristic Curves

## 4. PAT and Pump System (P&P) Modelling

#### Behaviour of the P&P Plant

## 5. Case Study

- Elevated tank—Variable ${Q}_{T}$, constant ${H}_{P}$
- Direct pumping—Variable ${Q}_{T}$, constant ${Q}_{P}$

- (a)
- A high difference in ground elevation between district 1 and district 2 and large turbined discharge
- (b)
- A low difference in ground elevation between district 1 and district 2 and small turbined discharge

## 6. Conclusions

## Author Contributions

## Conflicts of Interest

## References

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**Figure 1.**Pictures of the qualification laboratory of Caprari ltd (

**a**); and of HELab of University of Naples (

**b**).

**Figure 2.**Experimental normalized head (

**a**), power (

**b**) and efficiency (

**c**) of the HMU pump and regression curves.

**Figure 3.**Experimental normalized head (

**a**), power (

**b**) and efficiency (

**c**) of NC80 PAT and regression curves.

**Figure 8.**Behaviour of the P&P system for scenario $1a$ (

**I**,

**II**); $1b$ (

**III**,

**IV**); $2a$ (

**V**,

**VI**); and $2b$ (

**VII**,

**VIII**).

Measured Quantity | Maximum Uncertainty Value |
---|---|

Q | $2.0\%$ |

H | $1.5\%$ |

P | $2.0\%$ |

η | $3.2\%$ |

Specification | Value | Unit |
---|---|---|

Nominal speed | 2900 | rpm |

${Q}_{B}$ | $14.2$ | $\raisebox{1ex}{$\mathrm{L}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{s}$}\right.$ |

${H}_{B}$ | $78.9$ | m |

${\eta}_{B}$ | $73.0$ | % |

Specification | Value | Unit |
---|---|---|

Nominal speed | 1550 | rpm |

${Q}_{B}$ | $32.6$ | $\raisebox{1ex}{$\mathrm{L}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{s}$}\right.$ |

${H}_{B}$ | $14.2$ | m |

${\eta}_{B}$ | $63.2$ | % |

Casea | Caseb | |
---|---|---|

Supply condition 1 | Variable ${Q}_{T}$ (${\overline{Q}}_{T}=$ 40 $\raisebox{1ex}{$\mathrm{L}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{s}$}\right.$) | Variable ${Q}_{T}$ (${\overline{Q}}_{T}=$ 25 $\raisebox{1ex}{$\mathrm{L}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{s}$}\right.$) |

Variable ${H}_{T}$ | Variable ${H}_{T}$ | |

Variable ${Q}_{P}$ | Variable ${Q}_{P}$ | |

${H}_{P}=50$ m | ${H}_{P}=15$ m | |

${n}_{P}=4$ | ${n}_{P}=2$ | |

Supply condition 2 | Variable ${Q}_{T}$ (${\overline{Q}}_{T}=$ 40 $\raisebox{1ex}{$\mathrm{L}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{s}$}\right.$) | Variable ${Q}_{T}$ (${\overline{Q}}_{T}=$ 25 $\raisebox{1ex}{$\mathrm{L}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{s}$}\right.$) |

Variable ${H}_{T}$ | Variable ${H}_{T}$ | |

${Q}_{P}=4,4$ $\raisebox{1ex}{$\mathrm{L}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{s}$}\right.$ | ${Q}_{P}=6,4$ $\raisebox{1ex}{$\mathrm{L}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{s}$}\right.$ | |

Variable ${H}_{P}$ | Variable ${H}_{P}$ | |

${n}_{P}=4$ | ${n}_{P}=2$ |

Scenario | Turbined Average Power (kW) | Turbined Maximum Power (kW) | Pumped Average Power (kW | Pumped Maximum Power (kW) | Average Efficiency | Annual Energy Saving (MWh) |
---|---|---|---|---|---|---|

$1a$ | $8.95$ | $20.21$ | $3.52$ | $6.93$ | $0.39$ | 48.1–77.0 |

$1b$ | $2.27$ | $4.87$ | $0.93$ | $1.76$ | $0.41$ | 12.7–20.3 |

$2a$ | $8.8$ | $19.70$ | $3.10$ | $5.88$ | $0.35$ | 42.5–68.0 |

$2b$ | $2.28$ | $5.26$ | $1.01$ | $2.16$ | $0.44$ | 13.8–22.0 |

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**MDPI and ACS Style**

Carravetta, A.; Antipodi, L.; Golia, U.; Fecarotta, O.
Energy Saving in a Water Supply Network by Coupling a Pump and a Pump As Turbine (PAT) in a Turbopump. *Water* **2017**, *9*, 62.
https://doi.org/10.3390/w9010062

**AMA Style**

Carravetta A, Antipodi L, Golia U, Fecarotta O.
Energy Saving in a Water Supply Network by Coupling a Pump and a Pump As Turbine (PAT) in a Turbopump. *Water*. 2017; 9(1):62.
https://doi.org/10.3390/w9010062

**Chicago/Turabian Style**

Carravetta, Armando, Lauro Antipodi, Umberto Golia, and Oreste Fecarotta.
2017. "Energy Saving in a Water Supply Network by Coupling a Pump and a Pump As Turbine (PAT) in a Turbopump" *Water* 9, no. 1: 62.
https://doi.org/10.3390/w9010062