Aerodynamic Instability and Life-Limiting Effects of Inlet and Interstage Water Injection Into Gas Turbines

2004 ◽  
Vol 128 (3) ◽  
pp. 617-625 ◽  
Author(s):  
Klaus Brun ◽  
Rainer Kurz ◽  
Harold R. Simmons
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Water Injection ◽  
Axial Compressor ◽  
Careful Analysis ◽  
Operating Conditions ◽  
Aerodynamic Stability ◽  
Surge Margin ◽  
Power Enhancement ◽  
Aerodynamic Instability

Gas turbine power enhancement technologies, such as inlet fogging, interstage water injection, saturation cooling, inlet chillers, and combustor injection, are being employed by end users without evaluating the potentially negative effects these devices may have on the operational integrity of the gas turbine. Particularly, the effect of these add-on devices, off-design operating conditions, nonstandard fuels, and compressor degradation∕fouling on the gas turbine’s axial compressor surge margin and aerodynamic stability is often overlooked. Nonetheless, compressor aerodynamic instabilities caused by these factors can be directly linked to blade high-cycle fatigue and subsequent catastrophic gas turbine failure; i.e., a careful analysis should always proceed the application of power enhancement devices, especially if the gas turbine is operated at extreme conditions, uses older internal parts that are degraded and weakened, or uses nonstandard fuels. This paper discusses a simplified method to evaluate the principal factors that affect the aerodynamic stability of a single-shaft gas turbine’s axial compressor. As an example, the method is applied to a frame-type gas turbine and results are presented. These results show that inlet cooling alone will not cause gas turbine aerodynamic instabilities, but that it can be a contributing factor if for other reasons the machine’s surge margin is already slim. The approach described herein can be employed to identify high-risk applications and bound the gas turbine operating regions to limit the risk of blade life reducing aerodynamic instability and potential catastrophic failure.

Aerodynamic Instability and Life Limiting Effects of Inlet and Interstage Water Injection Into Gas Turbines

2005 ◽  
Author(s):  
Klaus Brun ◽  
Rainer Kurz ◽  
Harold R. Simmons
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Water Injection ◽  
Axial Compressor ◽  
Careful Analysis ◽  
Operating Conditions ◽  
Aerodynamic Stability ◽  
Surge Margin ◽  
Power Enhancement ◽  
Aerodynamic Instability

Gas turbine power enhancement technologies such as inlet fogging, interstage water injection, saturation cooling, inlet chillers, and combustor injection are being employed by end-users without evaluating the potentially negative effects these devices may have on the operational integrity of the gas turbine. Particularly, the effect of these add-on devices, off-design operating conditions, non-standard fuels, and compressor degradation/fouling on the gas turbine’s axial compressor surge margin and aerodynamic stability is often overlooked. Nonetheless, compressor aerodynamic instabilities caused by these factors can be directly linked to blade high-cycle fatigue and subsequent catastrophic gas turbine failure; i.e., a careful analysis should always proceed the application of power enhancement devices, especially if the gas turbine is operated at extreme conditions, uses older internal parts that are degraded and weakened, or uses non-standard fuels. This paper discusses a simplified method to evaluate the principal factors that affect the aerodynamic stability of a single shaft gas turbine’s axial compressor. As an example, the method is applied to a frame type gas turbine and results are presented. These results show that inlet cooling alone will not cause gas turbine aerodynamic instabilities but that it can be a contributing factor if for other reasons the machine’s surge margin is already slim. The approach described herein can be employed to identify high-risk applications and bound the gas turbine operating regions to limit the risk of blade life reducing aerodynamic instability and potential catastrophic failure.

Evaluation of Advanced Combustors for Dry NOx Suppression With Nitrogen Bearing Fuels in Utility and Industrial Gas Turbines

1982 ◽  
Vol 104 (2) ◽  
pp. 429-438 ◽  
Author(s):  
M. B. Cutrone ◽  
M. B. Hilt ◽  
A. Goyal ◽  
E. E. Ekstedt ◽  
J. Notardonato
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Pressure Ratio ◽  
Water Injection ◽  
Operating Conditions ◽  
Department Of Energy ◽  
Technical Program ◽  
Wide Range ◽  
Industrial Gas Turbines ◽  
Low Levels

The work described in this paper is part of the DOE/LeRC Advanced Conversion-Technology Project (ACT). The program is a multiple contract effort with funding provided by the Department of Energy, and technical program management provided by NASA LeRC. Combustion tests are in progress to evaluate the potential of seven advanced combustor concepts for achieving low NOx emissions for utility gas turbine engines without the use of water injection. Emphasis was on the development of the required combustor aerothermodynamic features for burning high nitrogen fuels. Testing was conducted over a wide range of operating conditions for a 12:1 pressure ratio heavy-duty gas turbine. Combustors were evaluated with distillate fuel, SRC-II coal-derived fuel, residual fuel, and blends. Test results indicate that low levels of NOx and fuel-bound nitrogen conversion can be achieved with rich-lean combustors for fuels with high fuel-bound nitrogen. In addition, ultra-low levels of NOx can be achieved with lean-lean combustors for fuels with low fuel-bound nitrogen.

Water Injection Evaporation in Frame 7EA Gas Turbine Wrapper

2017 ◽  
Author(s):  
Michele Bianchi ◽  
Andrea De Pascale ◽  
Francesco Melino ◽  
Antonio Peretto ◽  
Sasha Savic
Keyword(s):  
Gas Turbine ◽  
Droplet Size ◽  
Liquid Water ◽  
Gas Turbines ◽  
Water Injection ◽  
Steam Injection ◽  
Operating Conditions ◽  
Nox Abatement ◽  
The Impact ◽  
Calculation Code

A Southern California cogeneration plant is comprised of four GE-made Frame No 7, Model EA, heavy duty gas turbines driving Electrical Generators. Turbine exhaust gases are routed into the heat recovery steam generators (HRSG) of the split level. The HRSG are furnished with supplemental firing in order to boost the production of the steam. The produced NOX abatement is realized by the continuous steam injection and selective catalyst reduction (SCR). In order to reduce the steam consumption for NOX abatement, water injection in combustion chamber can be taken into account. Unfortunately, available gas turbine combustor cannot be used to inject water directly into the liner (and thus maximize the impact of water injection compared to steam injection); for this reason, an alternative solution was investigated which consists on water injection into the combustor wrapper. By doing this, effects on NOX abatement are similar to those of steam injection for power augmentation, namely only about 30% of water injected this way will actually quench the NOX, the rest flowing through the dilution holes. To ensure no impact of water injection on the combustor hardware’s integrity, any liquid droplets injected into the wrapper shall evaporate prior to reaching the liner. In order to estimate the behavior of liquid water droplets injected into the wrapper, a calculation code was developed by University of Bologna. This calculation code is able to estimate the evaporation rate of a spray of liquid water by calculating the droplets diameter reduction, the air temperature drop, etc. as function of boundary conditions. More in details, the aim of this study is to estimate the maximum droplet sizes to ensure the full evaporation of the water and to eliminate negative effects on the combustor life. In order to achieve this goal, a parametric study has been developed, changing the droplet size to calculate the time needed for full evaporation and compare this with the time of droplet travel from the injection point to the first dilution holes of the combustor liner. More in details, it was calculated, under various gas turbine operating conditions, what would be the maximal droplet size needed to evaporate within the available residence time into the wrapper.

Test Rig Design to Explore Water Droplet Behavior in a Four Stage Axial Compressor

2013 ◽  
Author(s):  
S. Clauss ◽  
J. P. Schnitzler ◽  
B. Barabas ◽  
P. S. Nagabhushan ◽  
F. K. Benra ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Experimental Research ◽  
Gas Turbines ◽  
Water Injection ◽  
Axial Compressor ◽  
Evaporation Process ◽  
Test Rig ◽  
Numerical Investigations ◽  
Stationary Test ◽  
Wall Interaction

The efficiency of gas turbine cycles can be enhanced by many applications and combinations according to the choice of the thermodynamic cycle. Gas turbine cycles which operate with humid air and water injection at different locations of the compressor are in the focus of present thermodynamic analysis and experimental research. Reasoned by their high potential in efficiency and power output augmentation, they have been implemented on many industrial gas turbines. The evaporation process of water droplets, especially at high temperature and pressure levels has been recently investigated with the laser based measurement technique Phase Doppler Particle Analyzer (PDPA) in detail in a stationary test rig at the University of Duisburg-Essen. The focus of these investigations was on the analysis of the evaporation process in a free stream or cross flow without droplet wall interaction [1–5]. In this paper the development of a novel four stage axial compressor test rig which is designed for water injection will be introduced and results of numerical investigations will be presented. This test rig has been designed to adopt the results from the stationary test rig to a real compressor. The first part of the paper deals with the mechanical and aerothermodynamic design of the test rig. Certain design parameters, the optical access for the PDPA measurements and a comparison between numerical and experimental results without water injection are outlined. In the second part of the paper, first comparative results from numerical investigations of the compressor performance in dry and wet compression operating conditions are presented. Furthermore, numerical results for droplet wall interaction in the four stage axial compressor are shown. This analysis outlines the need for further experimental research in the future to validate numerical methods with accurate droplet wall interaction behavior in turbomachines.

Water Injection Into Navy Gas-Turbine Combustors to Reduce NOx Emissions

1998 ◽  
Author(s):  
Herman B. Urbach ◽  
Donald T. Knauss ◽  
Balfour L. Wallace ◽  
John Emory ◽  
John Frese ◽  
...  
Keyword(s):  
Steady State ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Low Cost ◽  
Water Injection ◽  
Operating Conditions ◽  
Idle Speed ◽  
State Tests ◽  
Water Rates ◽  
Basic Engine

Land-based water injection into the combustor of gas turbines is a state-of-the-art technology, which is a low-risk, low-cost option for reduction of gas-turbine emissions. A controller for a water-injected combustor (WIC) system was designed for automatic control of water injection. Steady-state tests of the WIC system in an LM2500 propulsion-engine facility yielded basic engine-interactive data for the WIC’s unique automatic software logic. The steady-state tests demonstrated anticipated NOx reductions in conformity with proposed (but not implemented) California Air Resources Board (CARB) mandates. The controller automatically compensates for the effects of humidity, temperature and engine load. This automatic response was expressly designed to deliver acceptable water rates even during the abrupt power excursions encountered in emergencies, including collision-avoidance crashback maneuvers. The transient test data indicated unacceptable flameout in the engine during engine deceleration to idle speed. Detailed analyses of the flameouts show that the controller can reduce water flow within two deciseconds of a change in power demand. However, the residence time of water in the manifolds can be about a second for some operating conditions. Several fixes for this problem are described.

The Effect of Water Injection on Multi-Spool Gas Turbine Behaviour

2004 ◽  
Author(s):  
A. J. Meacock ◽  
A. J. White
Keyword(s):  
Gas Turbine ◽  
Power Output ◽  
Gas Turbines ◽  
Water Injection ◽  
Flow Characteristics ◽  
Operating Conditions ◽  
Water Droplets ◽  
Industrial Gas Turbines ◽  
Advanced Cycles ◽  
Gas Turbine Cycle

The injection of water droplets into industrial gas turbines is now common place and is central to several proposed advanced cycles. These cycles benefit from the subsequent reduction in compressor work, the increase in turbine work, and (in the case of recuperated cycles) reduction in compressor delivery temperature, which all act to increase the efficiency and power output. An investigation is presented here into the effect such water droplets will have on the operating point and flow characteristics of an aero-derivative gas turbine cycle. The paper first describes the development of a computer program to study the effects of water injection in multi-spool industrial gas turbines. The program can operate in two modes: the first uses pre-determined non-dimensional wet compressor maps to match the components and is instructive and fast but limited in scope; the second uses the compressor geometries as input and calculates the wet compressor operating conditions as and when required. As a result, it is more computationally demanding, but can cope with a wider range of circumstances. In both cases the compressor characteristics are calculated from a mean-line analysis using suitable loss, deviation and blockage models, coupled with Lagrangian-style droplet evaporation calculations. The program has been applied to a three-spool machine to address issues such as the effects of water-injection on power output and overall efficiency, and the off-design nature of the compressor operation.

Mapping and Predicting Air Flows in Gas Turbine Axial Compressors

2003 ◽  
Author(s):  
Robert J. McKee
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Axial Compressor ◽  
Operating Conditions ◽  
Control Panel ◽  
Airflow Rate ◽  
Computer Data ◽  
Design Point ◽  
Axial Compressors ◽  
Performance Curves

Determining the airflow through a gas turbine’s axial compressor is not a simple or one step process as many factors affect flow and there is seldom a flow meter or a means to directly measure airflow rate. Speed of the compressor, inlet pressure and temperature, and resistance or backpressure at the compressor’s outlet all affect the amount of airflow. The type of gas turbine, single or twin spool, the magnitude of power produced, the use of bleed or bypass valves, the power turbine speed, and operating conditions all have influences on the amount of airflow. Despite this, there are several reasons why an estimate of airflow is useful for understanding and describing the behavior and performance of gas turbines. The amount of airflow compared to fuel flow determines the composition and condition of the exhaust gases and is directly related to the turbine’s power output, heat rate, and waste heat recovery potential. A predicted airflow rate and the corresponding axial compressor discharge pressure can be used to identify deterioration in performance and to estimate emission characteristics of a unit. This paper presents an approach based on easily obtained gas turbine data, such as the design point data, test stand data, or manufacturer’s curves for the compressor. Compressor performance curves may be obtained from the manufacturer or by mapping compressor output during normal operations. A great deal of information has been presented in the literature about the performance of gas turbines and axial compressors but this paper focuses on methods that are sufficiently simple and direct that users can obtain an estimate of their unit’s airflow, References 1, 2, and 3. Some manufacturers provide computer data bases or on-line control panel estimates of gas turbine airflow but in these cases, the user has no idea what causes a change. Detailed performance curves for axial compressors are usually not available, however, through the methods presented in this paper, a reasonable approximation of the operating curves can be developed and used to estimate axial compressor airflow over the full range of normal operations. The methods described are based on tracking and mapping a compressor’s operations over a period of time and relating compressor output to other performance parameters and known conditions (design point) in order to establish a normally expected airflow rate.

scholarly journals A Comparative Study on Fault Detection Methods for Gas Turbine Combustion Systems

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 389
Author(s):  
Jinfu Liu ◽  
Zhenhua Long ◽  
Mingliang Bai ◽  
Linhai Zhu ◽  
Daren Yu
Keyword(s):  
Fault Detection ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Operating Conditions ◽  
Detection Methods ◽  
Distribution Model ◽  
Outlet Temperature ◽  
Combustion System ◽  
Comparison Results ◽  
Gas Turbine Combustion

As one of the core components of gas turbines, the combustion system operates in a high-temperature and high-pressure adverse environment, which makes it extremely prone to faults and catastrophic accidents. Therefore, it is necessary to monitor the combustion system to detect in a timely way whether its performance has deteriorated, to improve the safety and economy of gas turbine operation. However, the combustor outlet temperature is so high that conventional sensors cannot work in such a harsh environment for a long time. In practical application, temperature thermocouples distributed at the turbine outlet are used to monitor the exhaust gas temperature (EGT) to indirectly monitor the performance of the combustion system, but, the EGT is not only affected by faults but also influenced by many interference factors, such as ambient conditions, operating conditions, rotation and mixing of uneven hot gas, performance degradation of compressor, etc., which will reduce the sensitivity and reliability of fault detection. For this reason, many scholars have devoted themselves to the research of combustion system fault detection and proposed many excellent methods. However, few studies have compared these methods. This paper will introduce the main methods of combustion system fault detection and select current mainstream methods for analysis. And a circumferential temperature distribution model of gas turbine is established to simulate the EGT profile when a fault is coupled with interference factors, then use the simulation data to compare the detection results of selected methods. Besides, the comparison results are verified by the actual operation data of a gas turbine. Finally, through comparative research and mechanism analysis, the study points out a more suitable method for gas turbine combustion system fault detection and proposes possible development directions.

Comparative Life Cycle Assessment of Different Gas Turbine Axial Compressor Water Washing Systems

2020 ◽  
Author(s):  
Ilaria Dominizi ◽  
Serena Gabriele ◽  
Angela Serra ◽  
Domenico Borello
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Gas Turbine ◽  
Axial Compressor ◽  
Operating Conditions ◽  
Energy Field ◽  
Water Washing ◽  
Before And After ◽  
Reduce Emissions ◽  
Global Threat

Abstract Nowadays the climate change is widely recognized as a global threat by both public opinion and industries. Actions to mitigate its causes are gaining momentum within all industries. In the energy field, there is the necessity to reduce emissions and to improve technologies to preserve the environment. LCA analyses of products are fundamental in this context. In the present work, a life cycle assessment has been carried out to calculate the carbon footprint of different water washing processes, as well as their effectiveness in recovering Gas Turbine efficiency losses. Field data have been collected and analyzed to make a comparison of the GT operating conditions before and after the introduction of an innovative high flow online water washing technique. The assessments have been performed using SimaPro software and cover the entire Gas Turbine and Water Washing skids operations, including the airborne emissions, skid pump, the water treatment and the heaters.

Marine Gas Turbine Performance Model for More Electric Ships

2011 ◽  
Author(s):  
George M. Koutsothanasis ◽  
Anestis I. Kalfas ◽  
Georgios Doulgeris
Keyword(s):  
Gas Turbine ◽  
Fuel Consumption ◽  
Diesel Engines ◽  
Gas Turbines ◽  
Electric Propulsion ◽  
Operating Conditions ◽  
Prime Mover ◽  
Creep Life ◽  
Hull Fouling ◽  
Turbine Performance

This paper presents the benefits of the more electric vessels powered by hybrid engines and investigates the suitability of a particular prime-mover for a specific ship type using a simulation environment which can approach the actual operating conditions. The performance of a mega yacht (70m), powered by two 4.5MW recuperated gas turbines is examined in different voyage scenarios. The analysis is accomplished for a variety of weather and hull fouling conditions using a marine gas turbine performance software which is constituted by six modules based on analytical methods. In the present study, the marine simulation model is used to predict the fuel consumption and emission levels for various conditions of sea state, ambient and sea temperatures and hull fouling profiles. In addition, using the aforementioned parameters, the variation of engine and propeller efficiency can be estimated. Finally, the software is coupled to a creep life prediction tool, able to calculate the consumption of creep life of the high pressure turbine blading for the predefined missions. The results of the performance analysis show that a mega yacht powered by gas turbines can have comparable fuel consumption with the same vessel powered by high speed Diesel engines in the range of 10MW. In such Integrated Full Electric Propulsion (IFEP) environment the gas turbine provides a comprehensive candidate as a prime mover, mainly due to its compactness being highly valued in such application and its eco-friendly operation. The simulation of different voyage cases shows that cleaning the hull of the vessel, the fuel consumption reduces up to 16%. The benefit of the clean hull becomes even greater when adverse weather condition is considered. Additionally, the specific mega yacht when powered by two 4.2MW Diesel engines has a cruising speed of 15 knots with an average fuel consumption of 10.5 [tonne/day]. The same ship powered by two 4.5MW gas turbines has a cruising speed of 22 knots which means that a journey can be completed 31.8% faster, which reduces impressively the total steaming time. However the gas turbine powered yacht consumes 9 [tonne/day] more fuel. Considering the above, Gas Turbine looks to be the only solution which fulfills the next generation sophisticated high powered ship engine requirements.

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