scholarly journals A strategy for the robust forecasting of gas turbine health subjected to fouling

2021 ◽  
Vol 312 ◽  
pp. 11002
Author(s):  
Nicola Aldi ◽  
Nicola Casari ◽  
Ettore Fadiga ◽  
Riccardo Friso ◽  
Stefano Oliani ◽  
...  
Keyword(s):  
Gas Turbines ◽  
Residual Life ◽  
Fluid Dynamic ◽  
Operating Conditions ◽  
Solid Particles ◽  
Particle Injection ◽  
Uncertainty Sources ◽  
Internal Surfaces ◽  
And Performance ◽  
Health Parameters

Fouling represents a major problem for Gas Turbines (GTs) in both heavy-duty and aero-propulsion applications. Solid particles entering the engine can stick to the internal surfaces and form deposits. Components' lifetime and performance can dramatically vary as a consequence of this phenomenon. These effects impact the whole engine in terms of residual life, operating stability, and maintenance costs. In the High-Pressure Turbine (HPT), in particular, the high temperatures soft the particles and promote their adhesion, especially in the short term. Unfortunately, predicting the GT response to this detrimental issue is still an open problem for scientists. Furthermore, the stochastic variations of the components operating conditions increase the uncertainty of the forecasting results. In this work, a strategy to predict the effects of turbine fouling on the whole engine is proposed. A stationary Gas Path Analysis (GPA) has been performed for this scope to predict the GT health parameters. Their alteration as a consequence of fouling has been evaluated by scaling the turbine map. The scaling factor has been found by performing Computational Fluid Dynamic (CFD) simulations of a HPT nozzle with particle injection. Being its operating conditions strongly uncertain, a stochastic analysis has been conducted. The uncertainty sources considered are the circumferential hot core location and the turbulence level at the inlet. The study enables to build of confidence intervals on the GT health parameters predictions and represents a step forward towards a robust forecasting tool.

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.

Heavy Duty Gas Turbine Simulation: Global Performances Estimation and Secondary Air System Modifications

2006 ◽  
Author(s):  
Carlo Carcasci ◽  
Bruno Facchini ◽  
Stefano Gori ◽  
Luca Bozzi ◽  
Stefano Traverso
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Cooling System ◽  
Energy System ◽  
Operating Conditions ◽  
Coupled Analysis ◽  
Ambient Conditions ◽  
Air System ◽  
Secondary Air ◽  
And Performance

This paper reviews a modular-structured program ESMS (Energy System Modular Simulation) for the simulation of air-cooled gas turbines cycles, including the calculation of the secondary air system. The program has been tested for the Ansaldo Energia gas turbine V94.3A, which is one of the more advanced models in the family Vx4.3A with a rated power of 270 MW. V94.3A cooling system has been modeled with SASAC (Secondary Air System Ansaldo Code), the Ansaldo code used to predict the structure of the flow through the internal air system. The objective of the work was to investigate the tuning of the analytical program on the basis of the data from design and performance codes in use at Ansaldo Energy Gas Turbine Department. The results, both at base load over different ambient conditions and in critical off-design operating points (full-speed-no-load and minimum-load), have been compared with APC (Ansaldo Performance Code) and confirmed by field data. The coupled analysis of cycle and cooling network shows interesting evaluations for components life estimation and reliability during off-design operating conditions.

Damage Analysis of Gas Turbine Vanes Using a Thermal Fluid Dynamic and Mechanical Approach

2004 ◽  
Author(s):  
Enrico Marchegiano ◽  
Giancarlo Benelli ◽  
Paolo Gheri ◽  
Donato Aquaro
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
Residual Life ◽  
Crack Nucleation ◽  
Fluid Dynamic ◽  
Load Cycle ◽  
Combined Cycle ◽  
Operating Conditions ◽  
Turbine Vanes ◽  
Cycle Systems

Gas turbine combined–cycle systems work with high inlet temperatures, requiring the use of components made of advanced high temperature resistant materials and coatings. These components must be controlled to avoid serious damage to the plants. The durability of these materials and coatings is of great concern to equipment users. This paper deals with a procedure based on thermal fluid dynamic and mechanical integrated analyses of high temperature loaded components. The methodology is applied to uncooled last stator stages vanes of an industrial 165 Mw gas turbine. Several cracks were revealed on these vanes during periodical inspection and mechanical and metallographic investigations were performed. These analyses were used to identify the critical areas of the vanes, from which the component residual life depends on. The procedure was applied to study the damage undergone by gas turbine vanes to discover the causes of crack nucleation and the nucleation mechanism connected to load histories. It has a diagnostic scope, not a predictive one, but it can be considered as the first step of a residual life evaluation and, consequently, of a load cycle optimization: by modifying the future load histories, it could be possible evaluate the best operating conditions to extend component life. The numerical results of these analyses were compared with the damage to vane rows determined during periodical inspections. A good agreement between the analyses results and the inspection data was obtained in terms of critical points and crack locations. The implemented methodology seems to be a powerful tool for increasing the reliability of critical components of gas turbine combined–cycle systems.

Washing Effectiveness Assessment of Different Cleaners on a Small-Scale Multistage Compressor

2021 ◽  
Author(s):  
Alessandro Vulpio ◽  
Alessio Suman ◽  
Nicola Casari ◽  
Michele Pinelli ◽  
Craig Appleby ◽  
...  
Keyword(s):  
Gas Turbines ◽  
Axial Flow ◽  
Solid Particles ◽  
Rotor Blades ◽  
Small Scale ◽  
Internal Surfaces ◽  
Environmentally Sensitive ◽  
Flow Compressor ◽  
Processing Techniques ◽  
Effectiveness Assessment

Abstract Suspended micrometric particles are always present in the air swallowed by gas turbines. These solid particles can overpass the filters of heavy-duty gas turbines and deposit onto the internal surfaces of the compressor, leading to the overtime reduction of the machine performances, and, as a result, to the fuel consumption augmentation. A widely employed method to slow down the engine degradation is to wash the engine frequently. Over the years, the washing techniques have been continuously improved in order to reach the best compromise between low fluid consumption and high washing capabilities. In this work, an experimental campaign has been carried out to estimate the washing effectiveness on a multistage axial-flow compressor fouled with micrometric soot particles. The cleaning fluids tested in the present work were demineralized water and two cleaners provided by ZOK International Group ltd: a commercial cleaner available on the market (ZOK 27), and a new, under development, environmentally-sensitive formula. The fluids have been tested employing three droplet size distributions (with mean diameters of 20 μm, 50 μm, and 100 μm). The washing effectiveness has been assessed through image post-processing techniques by analyzing the pictures of the stator vanes and rotor blades taken in fouled and washed conditions. From the present investigation, two results arise. The finest droplets show a greater capability to remove soot deposits showing how, when the washing operation takes place during quasi-idle operating condition, the turbulent-driven motion spread smaller particles on a wider blade region. The second results is the demonstration how a environmentally-sensitive chemical formula allows the obtainment of good results in terms removal capability for the same amount of product. This finding could help the plant manager to operate the gas turbine with less constraints in terms of cost and rules.

Modelling and Assessment of Compressor Faults on Marine Gas Turbines

2012 ◽  
Author(s):  
I. Roumeliotis ◽  
N. Aretakis ◽  
K. Mathioudakis ◽  
E. A. Yfantis
Keyword(s):  
Gas Turbines ◽  
Engine Performance ◽  
Performance Model ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Maximum Speed ◽  
Performance Modelling ◽  
Engine Operation ◽  
Marine Propulsion ◽  
And Performance

Any prime mover exhibits the effects of wear and tear over time, especially when operating in a hostile environment. Marine gas turbines operation in the hostile marine environment results in the degradation of their performance characteristics. A method for predicting the effects of common compressor degradation mechanisms on the engine operation and performance by exploiting the “zooming” feature of current performance modelling techniques is presented. Specifically a 0D engine performance model is coupled with a higher fidelity compressor model which is based on the “stage stacking” method. In this way the compressor faults can be simulated in a physical meaningful way and the overall engine performance and off design operation of a faulty engine can be predicted. The method is applied to the case of a twin shaft engine, a configuration that is commonly used for marine propulsion. In the case of marine propulsion the operating profile includes a large portion of off-design operation, thus in order to assess the engine’s faults effects, the engine operation should be examined with respect to the marine vessel’s operation. For this reason, the engine performance model is coupled to a marine vessel’s mission model that evaluates the prime mover’s operating conditions. In this way the effect of a faulty engine on vessels’ mission parameters like overall fuel consumption, maximum speed, pollutant emissions and mission duration can be quantified.

Parameter Estimation and Performance Seeking of a Marine Gas Turbine Based on Extended Kalman Filter

2020 ◽  
Author(s):  
Zhitao Wang ◽  
Junxin Zhang ◽  
Wanling Qi ◽  
Shuying Li
Keyword(s):  
Parameter Estimation ◽  
Kalman Filter ◽  
Gas Turbine ◽  
Extended Kalman Filter ◽  
Gas Turbines ◽  
Operating Conditions ◽  
Stable Operation ◽  
Health State ◽  
Sqp Algorithm ◽  
And Performance

Abstract Marine gas turbines have been widely used and developed in the field of marine power. It is important to make them operated safely and efficiently. In this paper, a marine triaxial gas turbine is taken as an example to study the method of estimating the health state of the gas path using extended Kalman filter (EKF). To verify the accuracy of EKF, a comparison was made between linearized Kalman filtering (LKF) and EKF. In addition, the sequential quadratic programming (SQP) algorithm is used to seek the performance in case of gas path abnormal. The combination of parameter estimation and performance seeking forms a comprehensive method for diagnosis and optimization of marine gas turbines. The results show that the EKF method is an effective method for combining nonlinear systems with traditional Kalman filter. EKF has a good estimation effect on the gas path health state under different operating conditions. Also, the marine triaxial gas turbine achieved the target performance under the constraints of the SQP algorithm. Performance seeking restores the output power of the marine gas turbine and reduces the inlet and outlet temperatures of turbines. It can effectively prevent the problem of excessive combustion and ensure the safe and stable operation of the marine gas turbine.

Performance Improvement of a Hidden Ceiling Fan

2013 ◽  
Vol 479-480 ◽  
pp. 279-283
Author(s):  
Sheam Chyun Lin ◽  
Ming Yuan Hsieh ◽  
Cheng Ju Chang
Keyword(s):  
Flow Pattern ◽  
Performance Improvement ◽  
Horizontal Plane ◽  
Fluid Dynamic ◽  
Air Flow ◽  
Axial Flow ◽  
Critical Factor ◽  
Operating Conditions ◽  
Induced Flow ◽  
And Performance

A hidden ceiling-fan is the new design of embedding and hiding itself deeply into the ceiling floor. This design is different from conventional ceiling-fans or circulating fans that usually without an enclosing housing. The majority part of hidden ceiling-fan is embedded in the ceiling floor; hence the enclosing housing will be needed and be created to surround the axial-flow fan. The housing geometric is critical factor for hidden ceiling-fan because the air flow will pass though the horizontal plane of ceiling floor which the inlet and outlet are almost located at same plane. Consequently, the inappropriate design of enclosing housing will cause inhale-return phenomenon. It affects the induced flow performance of a hidden ceiling-fan. Few studies have investigated fan induced flow and its characteristics in a selected space. In this study, computational fluid dynamic (CFD) numerical simulation and experimental investigation were used to predict and valid the flow pattern with different geometric housing and operating conditions. The results showed that the flow pattern has different features as it leaves the fan downward the floor. The unique inhale-return phenomenon probably happens when inappropriate enclosing housing was designed such as high ring-plate and outlet-inlet ratio. Furthermore, the blockage effect will happen if the blockage distance is to short. In conclusion, thissystematic design investigation on hidden ceiling-fan not only provides the fan engineer’s design ability to avoid the inhale-return phenomenon, but also the predicting capability on the air flow induced characteristics and performance.

Life Management System for Hot-Gas-Path Components of Gas Turbines

1999 ◽  
Author(s):  
Yasushi Hayasaka ◽  
Nobuhiro Isobe ◽  
Shigeo Sakurai ◽  
Kazuhiko Kumata
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Management System ◽  
Residual Life ◽  
Combined Cycle ◽  
Operating Conditions ◽  
Life Assessment ◽  
Hot Gas ◽  
Life Management ◽  
Residual Life Assessment

Recently the number of gas-turbine-powered combined-cycle plants has been increasing because of their efficiency and environmental compatibility. Gas turbine operating conditions are severe, especially for hot-gas-path components. To improve the reliability of such components and to extend their life, we have developed a life management system based on a residual-life-assessment method. The system makes possible integrated residual-life-assessment based on numerical analyses, material destructive-tests, nondestructive inspections, statistical analyses of field machine data, and the use of a database. To develop the system, the primary damage mechanism for each component is clarified and material degradation is evaluated. For nozzles, the system describes a method of predicting the maximum surface crack growth. The validity of the methods is verified by assessment of the inspection data. This paper also describes optimization of operating cost and RAM (reliability, availability and maintainability).

scholarly journals Energy Performance Evaluation of a Ventilated Façade System through CFD Modeling and Comparison with International Standards

Energies ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 193
Author(s):  
Sofia Pastori ◽  
Riccardo Mereu ◽  
Enrico Sergio Mazzucchelli ◽  
Stefano Passoni ◽  
Giovanni Dotelli
Keyword(s):  
Solar Radiation ◽  
Energy Savings ◽  
Fluid Dynamic ◽  
Energy Performance ◽  
Operating Conditions ◽  
International Standards ◽  
Cfd Modeling ◽  
And Performance ◽  
Ventilated Facade ◽  
Air Conditioning Systems

Ventilated façades can help to reduce summer building thermal loads and, therefore, energy consumption due to air-conditioning systems thanks to the combined effect of the solar radiation reflection and the natural or forced ventilation into the cavity. The evaluation of ventilated façades behavior and performance is complex and requires a complete thermo-fluid dynamic analysis. In this study, a computational fluid dynamic (CFD) methodology has been developed for the complete assessment of the energy performance of a prefabricated timber–concrete composite ventilated façade module in different operating conditions. Global numerical results are presented as well as local ones in terms of heat flux, air velocity, and temperature inside the façade cavity. The results show the dependency of envelope efficiency on solar radiation, the benefits that natural convection brings on potential energy savings and the importance of designing an optimized façade geometry. The results concerning the façade behavior have been thoroughly compared with International Standards, showing the good accuracy of the model with respect to these well-known procedures. This comparison allowed also to highlight the International Standards procedures limits in evaluating the ventilated façade behavior with the necessary level of detail, with the risk of leading to design faults.

Active On-Line Protective Tuning Adjustment Technique to Achieve Better Availability and Performance in Pre-Mix DLN Combustion

2003 ◽  
Author(s):  
C. Koeneke ◽  
M. Nomura ◽  
H. Iba ◽  
T. Kawakami ◽  
T. Koga
Keyword(s):  
Gas Turbines ◽  
Pressure Fluctuations ◽  
Calorific Value ◽  
Combined Cycle ◽  
Operating Conditions ◽  
Protection System ◽  
Fuel Quality ◽  
Flame Instability ◽  
On Line ◽  
And Performance

Stable combustion of gas turbines is essential to ensure reliability, availability and achieve maximum component life capability. Combustor instabilities can trigger high-pressure fluctuations that are generally due to sudden changes in fuel calorific value or fuel quality, large ambient temperature swings, or sudden changes in operating load conditions. In order to protect against combustor instabilities, Mitsubishi developed an advanced monitoring and protection system known as the Advanced Combustor Pressure Fluctuation Monitoring (advanced CPFM) system. This on-line monitoring and protection system automatically tunes the air bypass valve, main and pilot fuel flows to maintain appropriate fuel/air ratio depending on the combustion chamber flame instability condition. The response to such actions successfully prevents flame out occurrence, combustion oscillation, and flame flash back under various modes while trying to maintain emissions within specified levels. This paper describes the operation and functionalities of the advanced CPFM system that has been tested at Mitsubishi’s in-house combined cycle power plant under real operating conditions.

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