# 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 |

## References

- Papadis, E.; Tsatsaronis, G. Challenges in the decarbonization of the energy sector. Energy
**2020**, 205, 118025. [Google Scholar] [CrossRef] - IRENA. World Energy Transitions Outlook: 1.5°C Pathway; IRENA: Abu Dhabi, United Arab Emirates, 2021; ISBN 978-92-9260-334-2. Available online: https://www.irena.org/publications/2021/March/World-Energy-Transitions-Outlook (accessed on 27 May 2021).
- Brouwer, A.S.; van den Broek, M.; Zappa, W.; Turkenburg, W.C.; Faaij, A. Least-cost options for integrating intermittent renewables in low-carbon power systems. Appl. Energy
**2016**, 161, 48–74. [Google Scholar] [CrossRef] [Green Version] - Pietzcker, R.C.; Osorio, S.; Rodrigues, R. Tightening EU ETS targets in line with the European Green Deal: Impacts on the decarbonization of the EU power sector. Appl. Energy
**2021**, 293, 116914. [Google Scholar] [CrossRef] - IRENA. Global Renewables Outlook: Energy Transformation 2050; International Renewable Energy Agency: Abu Dhabi, United Arab Emirates, 2020; ISBN 978-92-9260-238-3. Available online: https://www.irena.org/publications/2020/Apr/Global-Renewables-Outlook-2020 (accessed on 27 May 2021).
- Gonzalez-Salazar, M.A.; Kirsten, T.; Prchlik, L. Review of the operational flexibility and emissions of gas- and coal-fired power plants in a future with growing renewables. Renew. Sustain. Energy Rev.
**2018**, 82, 1497–1513. [Google Scholar] [CrossRef] - Knopf, B.; Nahmmacher, P.; Schmid, E. The European renewable energy target for 2030—An impact assessment of the electricity sector. Energy Policy
**2015**, 85, 50–60. [Google Scholar] [CrossRef] - Lunz, B.; Stöcker, P.; Eckstein, S.; Nebel, A.; Samadi, S.; Erlach, B.; Fischedick, M.; Elsner, P.; Sauer, D.U. Scenario-based comparative assessment of potential future electricity systems—A new methodological approach using Germany in 2050 as an example. Appl. Energy
**2016**, 171, 555–580. [Google Scholar] [CrossRef] [Green Version] - DinAli, M.N.; Dincer, I. Development and analysis of an integrated gas turbine system with compressed air energy storage for load leveling and energy management. Energy
**2018**, 163, 604–617. [Google Scholar] [CrossRef] - TERNA, S.p.A. Electricity System. 2021. Available online: https://www.terna.it/en/electric-system (accessed on 27 May 2021).
- Lynch, M.; Devine, M.T.; Bertsch, V. The role of power-to-gas in the future energy system: Market and portfolio effects. Energy
**2019**, 185, 1197–1209. [Google Scholar] [CrossRef] - Abudu, K.; Igie, U.; Minervino, O.; Hamilton, R. Gas turbine minimum environmental load extension with compressed air extraction for storage. Appl. Therm. Eng.
**2020**, 180, 115869. [Google Scholar] [CrossRef] - Abudu, K.; Igie, U.; Roumeliotis, I.; Hamilton, R. Impact of gas turbine flexibility improvements on combined cycle gas turbine performance. Appl. Therm. Eng.
**2021**, 189, 116703. [Google Scholar] [CrossRef] - Aalburg, C.; Szymanski, A.; Schwagerus, A.; Liska, J.; Cerny, V.; Wiedermann, A.; Bernstrauch, O.; Benvenuto, M. Special Technical Session: TURBO-REFLEX European Project. In Proceedings of the 14th European Turbomachinery Conference (ETC14), Gdansk, Poland, 12–16 April 2021. [Google Scholar]
- Mosele, S.G.; Garbarino, T.; Schneider, A.; Cozzi, L.; Arnone, A.; Goinis, G.; Hedkvist, S. Compressor Retrofittable Solutions in Heavy-Duty Gas Turbines for Minimum Environmental Load Reduction. E3S Web Conf.
**2019**, 113, 01012. [Google Scholar] [CrossRef] [Green Version] - Ricci, M.; Mosele, S.G.; Benvenuto, M.; Pio, A.; Pacciani, R.; Marconcini, M. Retrofittable Solutions Capability for a Gas Turbine Compressor. Int. J. Turbomach. Propuls. Power
**2022**, 7, 3. [Google Scholar] [CrossRef] - Goinis, G.; Benvenuto, M.; Mosele, S.G.; Schneider, A. Simulation of a Multistage Compressor at Low Load Operation with Additional Bleed Air Extraction for Minimum Environmental Load Reduction. In Proceedings of the Global Power & Propulsion Society (GPPS) Technical Conference 2022 (GPPS Chania22), Chania, Greece, 18–20 September 2022. [Google Scholar]
- Arnone, A. Viscous Analysis of Three-Dimensional Rotor Flow Using a Multigrid Method. J. Turbomach.
**1994**, 116, 435–445. [Google Scholar] [CrossRef] - Pacciani, R.; Marconcini, M.; Arnone, A. Comparison of the AUSM+-up and Other Advection Schemes for Turbomachinery Applications. Shock Waves
**2019**, 29, 705–716. [Google Scholar] [CrossRef] - Jameson, A.; Schmidt, W.; Turkel, E. Numerical Solutions of the Euler Equations by Finite Volume Methods Using Runge–Kutta Time–Stepping Schemes. In Proceedings of the 14th Fluid and Plasma Dynamics Conference, Palo Alto, CA, USA, 23–25 June 1981. AIAA paper 81–1259. [Google Scholar]
- Burberi, C.; Michelassi, V.; Scotti del Greco, A.; Lorusso, S.; Tapinassi, L.; Marconcini, M.; Pacciani, R. Validation of steady and unsteady CFD strategies in the design of axial compressors for gas turbine engines. Aerosp. Sci. Technol.
**2020**, 107, 106307. [Google Scholar] [CrossRef] - Giles, M.B. Non-Reflecting Boundary Conditions for the Euler Equations; Technical report, CFDL Report 88-1; Dept. of Aeronautics & Astronautics, MIT: Cambridge, MA, USA, 1988. [Google Scholar]
- Giles, M.B. UNSFLO: A Numerical Method for Unsteady Inviscid Flow in Turbomachinery; Technical report, GTL 195; Department of Aeronautics & Astronautics, MIT: Cambridge, MA, USA, 1988. [Google Scholar]
- Cioffi, M.; Puppo, E.; Silingardi, A. Fanno Design of Blow-Off Lines in Heavy Duty Gas Turbine. In Proceedings of the ASME Turbo Expo 2013: Turbine Technical Conference and Exposition, San Antonio, TX, USA, 3–7 June 2013. [Google Scholar] [CrossRef]
- Cioffi, M.; Piola, S.; Puppo, E.; Silingardi, A.; Bonzani, F. Minimum Environmental Load Reduction in Heavy Duty Gas Turbine by Bleeding Lines. In Proceedings of the ASME Turbo Expo 2014: Turbine Technical Conference and Exposition, Düsseldorf, Germany, 16–20 June 2014. [Google Scholar] [CrossRef]
- Wilcox, D.C. Multiscale Model for Turbulent Flows. AIAA J.
**1988**, 26, 1311–1320. [Google Scholar] [CrossRef] - Cozzi, L.; Rubechini, F.; Giovannini, M.; Marconcini, M.; Arnone, A.; Schneider, A.; Astrua, P. Capturing Radial Mixing in Axial Compressors With Computational Fluid Dynamics. J. Turbomach.
**2019**, 141, 031012. [Google Scholar] [CrossRef]

**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