Advances in Gas Turbine Technology and the Digital Computer

1996 ◽  
Author(s):  
Melvin Platt
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
High Speed ◽  
Historical Context ◽  
Interactive Operation ◽  
Technology Advancement ◽  
Coherent Image ◽  
Key Technologies ◽  
The Impact ◽  
Digital Computers

Recent advances in gas turbine technology from computational fluid dynamics (CFD) to concurrent engineering are identified and discussed. These advances are placed in a historical context. Parallels are drawn between advances in gas turbine technology and digital computers. The advent of high-speed digital computers in the late 50s, followed by interactive operation and display graphics in the 70s. and orders-of-magnitude increases in affordable processing speed more recently, have each enabled key technologies for the gas turbine. Examples of such key technologies are given and their evolution is considered. Further, the impact of that technology on gas turbine development is discussed. Those perspectives provide a more coherent image of technology advancement, and thus a greater ability to identify new and future advances that will effect the evolution of gas turbines. The paper concludes with a look into the near future of gas turbine technology.

Impact of a Combustor–Turbine Interface on Turbine Vane Aerodynamics and Film Cooling

2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Andreas Lerch ◽  
Rainer Bauer ◽  
Joerg Krueckels ◽  
Marc Henze
Keyword(s):  
Gas Turbine ◽  
Film Cooling ◽  
Gas Turbines ◽  
High Speed ◽  
Swirling Flow ◽  
Numerical Study ◽  
Heavy Duty ◽  
Film Cooling Effectiveness ◽  
Transition Piece ◽  
The Impact

Abstract Optimizing the aerothermal performance of the combustor–turbine interface is an important factor in enhancing the efficiency of heavy-duty gas turbines. Also, it is a key requirement to fulfill the lifetime in this hottest area of the gas turbine. Typically transition pieces of can combustors induce a highly nonuniform swirling flow at the turbine inlet. In order to better understand the impact of the nonuniform combustor flow at the first stage vanes, a combined experimental and numerical study was carried out. The experimental facility consisted of a high-speed linear cascade with four vane passages, including an upstream transition piece, which was representative of a heavy-duty gas turbine can combustor–turbine interface geometry. The experiments were conducted at engine representative Mach numbers, and film cooling effectiveness measurements were performed at three different blowing ratios. Computational fluid dynamics (CFD) Reynolds-averaged Navier–Stokes simulations were undertaken using a commercial flow solver. The numerical model was first validated with the experimental data, using inlet traverse five-hole probe measurements, pressure taps along the airfoil perimeter, and oil flow visualization results. The investigation shows that the position of the vane relative to the combustor transition piece has a significant impact on the vane aerodynamics and also film cooling behavior. This understanding was important for a robust first vane aerothermal design of the GT36.

Impact of a Combustor-Turbine Interface on Turbine Vane Aerodynamics and Film Cooling

2019 ◽  
Author(s):  
A. Lerch ◽  
R. Bauer ◽  
J. Krueckels ◽  
M. Henze
Keyword(s):  
Gas Turbine ◽  
Film Cooling ◽  
Gas Turbines ◽  
High Speed ◽  
Swirling Flow ◽  
Numerical Study ◽  
Heavy Duty ◽  
Film Cooling Effectiveness ◽  
Transition Piece ◽  
The Impact

Abstract Optimizing the aero-thermal performance of the combustor-turbine interface is an important factor in enhancing the efficiency of heavy-duty gas turbines. Also, it is a key requirement to fulfill the lifetime in this hottest area of the gas turbine. Typically transition pieces of can combustors induce a highly non-uniform swirling flow at the turbine inlet. In order to better understand the impact of the non-uniform combustor flow at the first stage vanes, a combined experimental and numerical study was carried out. The experimental facility consisted of a high speed linear cascade with four vane passages, including an upstream transition piece, which was representative of a heavy duty gas turbine can combustor-turbine interface geometry. The experiments were conducted at engine representative Mach numbers and film cooling effectiveness measurements were performed at three different blowing ratios. CFD RANS simulations were undertaken using a commercial flow solver. The numerical model was first validated with the experimental data, using inlet traverse 5-hole probe measurements, pressure taps along the airfoil perimeter and oil flow visualization results. The investigation shows that the position of the vane relative to the combustor transition piece has a significant impact on the vane aerodynamics and also film cooling behavior. This understanding was key to a robust first vane aerothermal design of the GT36.

scholarly journals Comprehensive Thermodynamic Analysis of the Humphrey Cycle for Gas Turbines with Pressure Gain Combustion

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3521 ◽  
Author(s):  
Panagiotis Stathopoulos
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Combustion Process ◽  
Ideal Gas ◽  
Point Of View ◽  
Pressure Gain Combustion ◽  
Combustion Technology ◽  
Secondary Air ◽  
And Performance ◽  
The Impact

Conventional gas turbines are approaching their efficiency limits and performance gains are becoming increasingly difficult to achieve. Pressure Gain Combustion (PGC) has emerged as a very promising technology in this respect, due to the higher thermal efficiency of the respective ideal gas turbine thermodynamic cycles. Up to date, only very simplified models of open cycle gas turbines with pressure gain combustion have been considered. However, the integration of a fundamentally different combustion technology will be inherently connected with additional losses. Entropy generation in the combustion process, combustor inlet pressure loss (a central issue for pressure gain combustors), and the impact of PGC on the secondary air system (especially blade cooling) are all very important parameters that have been neglected. The current work uses the Humphrey cycle in an attempt to address all these issues in order to provide gas turbine component designers with benchmark efficiency values for individual components of gas turbines with PGC. The analysis concludes with some recommendations for the best strategy to integrate turbine expanders with PGC combustors. This is done from a purely thermodynamic point of view, again with the goal to deliver design benchmark values for a more realistic interpretation of the cycle.

scholarly journals Wall Temperature Measurements in Gas Turbine Combustors With Thermographic Phosphors

2018 ◽  
Vol 141 (4) ◽  
Author(s):  
Patrick Nau ◽  
Zhiyao Yin ◽  
Oliver Lammel ◽  
Wolfgang Meier
Keyword(s):  
Gas Turbine ◽  
Wall Temperature ◽  
Gas Turbines ◽  
High Speed ◽  
Bluff Body ◽  
Temperature Measurements ◽  
Transient Temperature ◽  
High Time Resolution ◽  
Ceramic Surface ◽  
Precessing Vortex Core

Phosphor thermometry has been developed for wall temperature measurements in gas turbines and gas turbine model combustors. An array of phosphors has been examined in detail for spatially and temporally resolved surface temperature measurements. Two examples are provided, one at high pressure (8 bar) and high temperature and one at atmospheric pressure with high time resolution. To study the feasibility of this technique for full-scale gas turbine applications, a high momentum confined jet combustor at 8 bar was used. Successful measurements up to 1700 K on a ceramic surface are shown with good accuracy. In the same combustor, temperatures on the combustor quartz walls were measured, which can be used as boundary conditions for numerical simulations. An atmospheric swirl-stabilized flame was used to study transient temperature changes on the bluff body. For this purpose, a high-speed setup (1 kHz) was used to measure the wall temperatures at an operating condition where the flame switches between being attached (M-flame) and being lifted (V-flame) (bistable). The influence of a precessing vortex core (PVC) present during M-flame periods is identified on the bluff body tip, but not at positions further inside the nozzle.

Boundary Layer Flashback Limits of Hydrogen-Methane-Air Flames in a Generic Swirl Burner at Gas Turbine Relevant Conditions

2020 ◽  
Author(s):  
Dominik Ebi ◽  
Peter Jansohn
Keyword(s):  
Boundary Layer ◽  
Gas Turbine ◽  
Wall Temperature ◽  
Gas Turbines ◽  
High Speed ◽  
Cooling System ◽  
Atmospheric Conditions ◽  
Preheat Temperature ◽  
Swirl Burner ◽  
Wide Range

Abstract Operating stationary gas turbines on hydrogen-rich fuels offers a pathway to significantly reduce greenhouse gas emissions in the power generation sector. A key challenge in the design of lean-premixed burners, which are flexible in terms of the amount of hydrogen in the fuel across a wide range and still adhere to the required emissions levels, is to prevent flame flashback. However, systematic investigations on flashback at gas turbine relevant conditions to support combustor development are sparse. The current work addresses the need for an improved understanding with an experimental study on boundary layer flashback in a generic swirl burner up to 7.5 bar and 300° C preheat temperature. Methane-hydrogen-air flames with 50 to 85% hydrogen by volume were investigated. High-speed imaging was applied to reveal the flame propagation pathway during flashback events. Flashback limits are reported in terms of the equivalence ratio for a given pressure, preheat temperature, bulk flow velocity and hydrogen content. The wall temperature of the center body along which the flame propagated during flashback events has been controlled by an oil heating/cooling system. This way, the effect any of the control parameters, e.g. pressure, had on the flashback limit was de-coupled from the otherwise inherently associated change in heat load on the wall and thus change in wall temperature. The results show that the preheat temperature has a weaker effect on the flashback propensity than expected. Increasing the pressure from atmospheric conditions to 2.5 bar strongly increases the flashback risk, but hardly affects the flashback limit beyond 2.5 bar.

AI Assisted High Fidelity Multi-Physics Digital Twin of Industrial Gas Turbines

2021 ◽  
Author(s):  
Senthil Krishnababu ◽  
Omar Valero ◽  
Roger Wells
Keyword(s):  
Gas Turbine ◽  
Data Storage ◽  
Gas Turbines ◽  
Building Blocks ◽  
Data Driven ◽  
High Fidelity ◽  
Test Field ◽  
Operating Characteristics ◽  
Digital Twin ◽  
The Impact

Abstract Data driven technologies are revolutionising the engineering sector by providing new ways of performing day to day tasks through the life cycle of a product as it progresses through manufacture, to build, qualification test, field operation and maintenance. Significant increase in data transfer speeds combined with cost effective data storage, and ever-increasing computational power provide the building blocks that enable companies to adopt data driven technologies such as data analytics, IOT and machine learning. Improved business operational efficiency and more responsive customer support provide the incentives for business investment. Digital twins, that leverages these technologies in their various forms to converge physics and data driven models, are therefore being widely adopted. A high-fidelity multi-physics digital twin, HFDT, that digitally replicates a gas turbine as it is built based on part and build data using advanced component and assembly models is introduced. The HFDT, among other benefits enables data driven assessments to be carried out during manufacture and assembly for each turbine allowing these processes to be optimised and the impact of variability or process change to be readily evaluated. On delivery of the turbine and its associated HFDT to the service support team the HFDT supports the evaluation of in-service performance deteriorations, the impact of field interventions and repair and the changes in operating characteristics resulting from overhaul and turbine upgrade. Thus, creating a cradle to grave physics and data driven twin of the gas turbine asset. In this paper, one branch of HFDT using a power turbine module is firstly presented. This involves simultaneous modelling of gas path and solid using high fidelity CFD and FEA which converts the cold geometry to hot running conditions to assess the impact of various manufacturing and build variabilities. It is shown this process can be executed within reasonable time frames enabling creation of HFDT for each turbine during manufacture and assembly and for this to be transferred to the service team for deployment during field operations. Following this, it is shown how data driven technologies are used in conjunction with the HFDT to improve predictions of engine performance from early build information. The example shown, shows how a higher degree of confidence is achieved through the development of an artificial neural network of the compressor tip gap feature and its effect on overall compressor efficiency.

The Effect of Transient Fuel Staging on Self-Excited Instabilities in a Multi-Nozzle Model Gas Turbine Combustor

2017 ◽  
Author(s):  
Wyatt Culler ◽  
Janith Samarasinghe ◽  
Bryan D. Quay ◽  
Domenic A. Santavicca ◽  
Jacqueline O’Connor
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
High Speed ◽  
Equivalence Ratio ◽  
Growth Time ◽  
Stable Operation ◽  
Time Constants ◽  
Decay Times ◽  
Fuel Staging ◽  
Passive Techniques

Combustion instability in gas turbines can be mitigated using active techniques or passive techniques, but passive techniques are almost exclusively used in industrial settings. While fuel staging, a common passive technique, is effective in reducing the amplitude of self-excited instabilities in gas turbine combustors at steady-state conditions, the effect of transients in fuel staging on self-excited instabilities is not well understood. This paper examines the effect of fuel staging transients on a laboratory-scale five-nozzle can combustor undergoing self-excited instabilities. The five nozzles are arranged in a four-around-one configuration and fuel staging is accomplished by increasing the center nozzle equivalence ratio. When the global equivalence ratio is φ = 0.70 and all nozzles are fueled equally, the combustor undergoes self-excited oscillations. These oscillations are suppressed when the center nozzle equivalence ratio is increased to φ = 0.80 or φ = 0.85. Two transient staging schedules are used, resulting in transitions from unstable to stable operation, and vice-versa. It is found that the characteristic instability decay times are dependent on the amount of fuel staging in the center nozzle. It is also found that the decay time constants differ from the growth time constants, indicating hysteresis in stability transition points. High speed CH* chemiluminescence images in combination with dynamic pressure measurements are used to determine the instantaneous phase difference between the heat release rate fluctuation and the combustor pressure fluctuation throughout the combustor. This analysis shows that the instability onset process is different from the instability decay process.

Uncertainty Analysis of Inflow Conditions on an HPT Gas Turbine Nozzle: Effect on Particle Deposition

2020 ◽  
Author(s):  
R. Friso ◽  
N. Casari ◽  
M. Pinelli ◽  
A. Suman ◽  
F. Montomoli
Keyword(s):  
Gas Turbine ◽  
Energy Efficient ◽  
Gas Turbines ◽  
Particle Deposition ◽  
Operating Conditions ◽  
Wide Range ◽  
And Performance ◽  
Gas Turbine Nozzle ◽  
The Impact ◽  
Inflow Conditions

Abstract Gas turbines (GT) are often forced to operate in harsh environmental conditions. Therefore, the presence of particles in their flow-path is expected. With this regard, deposition is a problem that severely affects gas turbine operation. Components’ lifetime and performance can dramatically vary as a consequence of this phenomenon. Unfortunately, the operating conditions of the machine can vary in a wide range, and they cannot be treated as deterministic. Their stochastic variations greatly affect the forecasting of life and performance of the components. In this work, the main parameters considered affected by the uncertainty are the circumferential hot core location and the turbulence level at the inlet of the domain. A stochastic analysis is used to predict the degradation of a high-pressure-turbine (HPT) nozzle due to particulate ingestion. The GT’s component analyzed as a reference is the HPT nozzle of the Energy-Efficient Engine (E3). The uncertainty quantification technique used is the probabilistic collocation method (PCM). This work shows the impact of the operating conditions uncertainties on the performance and lifetime reduction due to deposition. Sobol indices are used to identify the most important parameter and its contribution to life. The present analysis enables to build confidence intervals on the deposit profile and on the residual creep-life of the vane.

Short-Term Optimization of a Combined Cycle Power Plant Integrated With an Inlet Air Conditioning Unit

2020 ◽  
Author(s):  
Weimar Mantilla ◽  
José García ◽  
Rafael Guédez ◽  
Alessandro Sorce
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Air Conditioning ◽  
Combined Cycle ◽  
Plant Performance ◽  
Mixed Integer ◽  
Environmental Load ◽  
Turbine Inlet ◽  
The Impact

Abstract Under new scenarios with high shares of variable renewable electricity, combined cycle gas turbines (CCGT) are required to improve their flexibility, in terms of ramping capabilities and part-load efficiency, to help balance the power system. Simultaneously, liberalization of electricity markets and the complexity of its hourly price dynamics are affecting the CCGT profitability, leading the need for optimizing its operation. Among the different possibilities to enhance the power plant performance, an inlet air conditioning unit (ICU) offers the benefit of power augmentation and “minimum environmental load” (MEL) reduction by controlling the gas turbine inlet temperature using cold thermal energy storage and a heat pump. Consequently, an evaluation of a CCGT integrated with this inlet conditioning unit including a day-ahead optimized operation strategy was developed in this study. To establish the hourly dispatch of the power plant and the operation mode of the inlet conditioning unit to either cool down or heat up the gas turbine inlet air, a mixed-integer linear optimization (MILP) was formulated using MATLAB, aiming to maximize the operational profit of the plant within a 24-hours horizon. To assess the impact of the proposed unit operating under this dispatch strategy, historical data of electricity and natural gas prices, as well as meteorological data and CO2 emission allowances price, have been used to perform annual simulations of a reference power plant located in Turin, Italy. Furthermore, different equipment capacities and parameters have been investigated to identify trends of the power plant performance. Lastly, a sensitivity analysis on market conditions to test the control strategy response was also considered. Results indicate that the inlet conditioning unit, together with the dispatch optimization, increases the power plant’s operational profit by achieving a wider operational range, particularly important during peak and off-peak periods. For the specific case study, it is estimated that the net present value of the CCGT integrated with the ICU is 0.5% higher than the power plant without the unit. In terms of technical performance, results show that the unit reduces the minimum environmental load by approximately 1.34% and can increase the net power output by 0.17% annually.

Experimental Development of On-Line Flame Transfer Function Measurements for Fielded Gas Turbines

2021 ◽  
Author(s):  
Austin Matthews ◽  
Anna Cobb ◽  
Subodh Adhikari ◽  
David Wu ◽  
Tim Lieuwen ◽  
...  
Keyword(s):  
Transfer Function ◽  
Heat Release ◽  
Gas Turbine ◽  
Gas Turbines ◽  
High Speed ◽  
Transfer Functions ◽  
Full Scale ◽  
Fuel Injector ◽  
Experimental Development ◽  
On Line

Abstract Understanding thermoacoustic instabilities is essential for the reliable operation of gas turbine engines. To complicate this understanding, the extreme sensitivity of gas turbine combustors can lead to instability characteristics that differ across a fleet. The capability to monitor flame transfer functions in fielded engines would provide valuable data to improve this understanding and aid in gas turbine operability from R&D to field tuning. This paper presents a new experimental facility used to analyze performance of full-scale gas turbine fuel injector hardware at elevated pressure and temperature. It features a liquid cooled, fiber-coupled probe that provides direct optical access to the heat release zone for high-speed chemiluminescence measurements. The probe was designed with fielded applications in mind. In addition, the combustion chamber includes an acoustic sensor array and a large objective window for verification of the probe using high-speed chemiluminescence imaging. This work experimentally demonstrates the new setup under scaled engine conditions, with a focus on operational zones that yield interesting acoustic tones. Results include a demonstration of the probe, preliminary analysis of acoustic and high speed chemiluminescence data, and high speed chemiluminescence imaging. The novelty of this paper is the deployment of a new test platform that incorporates full-scale engine hardware and provides the ability to directly compare acoustic and heat release response in a high-temperature, high-pressure environment to determine the flame transfer functions. This work is a stepping-stone towards the development of an on-line flame transfer function measurement technique for production engines in the field.

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