# Predicting the Impact of Compressor Flexibility Improvements on Heavy-Duty Gas Turbines for Minimum and Base Load Conditions

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## Abstract

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## 1. Introduction

## 2. Experimental Setup

- IGV and EB1 (first extraction slot) valve position;
- Ambient temperature, pressure and relative humidity;
- Grid frequency;
- Inlet compressor temperature and pressure;
- Outlet compressor temperature and pressure.

## 3. Computational Framework

## 4. Partial Load Conditions

## 5. Minimum Environmental Load Condition

## 6. Conclusions

## Author Contributions

## Funding

## Data Availability Statement

## Conflicts of Interest

## Abbreviations

CV | stator blade |

CB | r otor blade |

EB | extraction bleed |

MEL | minimum environmental load |

BO | blow off |

IGV | inlet guide vane |

OGV | outlet guide vane |

RES | renewable energy sources |

TET | turbine exhaust temperature |

TIT | turbine inlet temperature |

IX | extra-closure |

EXP | experimental measurements |

T | temperature |

p | pressure |

$\varphi $ | stage load coefficient |

$\psi $ | stage flow coefficient |

$\beta $ | pressure ratio |

$\eta $ | efficiency |

W | power |

$\dot{m}$ | mass flow rate |

$DF$ | diffusion factor |

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**Figure 1.**Electricity generation scenario, Remap case 2017–2050, IRENA [5].

**Figure 2.**Typical daily Italian grid electricity demand, May 2021, TERNA S.p.A. [10].

**Figure 4.**Average dimensional inlet total temperature and total pressure for the six cases experimentally tested by Ansaldo Energia Switzerland.

**Figure 5.**Compressor inlet mass flow rate (

**a**), polytropic efficiency (

**b**), and isentropic efficiency (

**c**) for the six cases experimentally tested by Ansaldo Energia Switzerland.

**Figure 6.**Discharge outlet total temperature for the six cases experimentally tested by Ansaldo Energia Switzerland.

**Figure 7.**Measured and predicted total temperature (

**a**) and static pressure (

**b**) distributions at casing for the six configurations experimentally tested by Ansaldo Energia Switzerland.

**Figure 8.**View of IGV with the first two stages, recirculating flow regions highlighted by iso-surface of zero axial velocity.

**Figure 9.**Test matrix overall pressure ratio (

**a**) and polytropic efficiency (

**b**) for the six configurations analyzed.

**Figure 10.**Test matrix stage flow coefficient (

**a**) and stage load coefficient (

**b**) for the six configurations analyzed.

**Figure 11.**Test matrix diffusion factor for the working line condition for the six configurations analyzed.

**Figure 13.**Recirculation flow regions highlighted by iso-surface of zero axial velocity for the 15C MEL IX BO operating condition.

Configuration | Stagger Angle [%] |
---|---|

T03 | 32.1 |

T08 | 35.9 |

T11 | 41.7 |

T12 | 27.3 |

T17 | 100.0 |

T20 | 72.9 |

Ambient Temp. | IGV Position | Blow-Off Valve |
---|---|---|

Ref | standard | - |

Ref | standard | 12% |

Low | standard | - |

Low | standard | 12% |

Ref | IX | - |

Ref | IX | 12% |

Low | IX | - |

Low | IX | 12% |

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**MDPI and ACS Style**

Ricci, M.; Benvenuto, M.; Mosele, S.G.; Pacciani, R.; Marconcini, M.
Predicting the Impact of Compressor Flexibility Improvements on Heavy-Duty Gas Turbines for Minimum and Base Load Conditions. *Energies* **2022**, *15*, 7546.
https://doi.org/10.3390/en15207546

**AMA Style**

Ricci M, Benvenuto M, Mosele SG, Pacciani R, Marconcini M.
Predicting the Impact of Compressor Flexibility Improvements on Heavy-Duty Gas Turbines for Minimum and Base Load Conditions. *Energies*. 2022; 15(20):7546.
https://doi.org/10.3390/en15207546

**Chicago/Turabian Style**

Ricci, Martina, Marcello Benvenuto, Stefano Gino Mosele, Roberto Pacciani, and Michele Marconcini.
2022. "Predicting the Impact of Compressor Flexibility Improvements on Heavy-Duty Gas Turbines for Minimum and Base Load Conditions" *Energies* 15, no. 20: 7546.
https://doi.org/10.3390/en15207546