Ash Behavior During Combustion and Deposition in Coal-Fueled Gas Turbines

1987 ◽  
Vol 109 (3) ◽  
pp. 325-330 ◽  
Author(s):  
C. L. Spiro ◽  
S. G. Kimura ◽  
C. C. Chen
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Alkali Metals ◽  
Coal Ash ◽  
Water Mixture ◽  
Corrosion Rates ◽  
Petroleum Fuels

Chemical and physical transformations of coal ash during combustion and deposition in gas turbine environments have been studied. Extensive characterization of the coal-water mixture fuel and deposits obtained on deposition pins and turbine nozzle vanes has been performed. The behavior of alkali metals has been found to be much different from that for petroleum fuels, resulting in lower than expected deposition and probable reduced corrosion rates.

The Ethanol-Water Humidification Process in EvGT Cycles

2004 ◽  
Author(s):  
Marcus Thern ◽  
Torbjo¨rn Lindquist ◽  
Tord Torisson
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Power Production ◽  
Test Facility ◽  
Level Energy ◽  
Water Mixture ◽  
Evaporation Process ◽  
Heating Value ◽  
Lower Heating Value ◽  
Lower Heating

Ethanol from bio-products has become an important fuel for future power production. However, the present production technology is rather expensive. This paper focuses on how to lower the production cost of ethanol extraction from mash, and to use the ethanol as a primary fuel in gas turbines for heat and power production. Today, ethanol is produced during distillation by supplying energy to extract the ethanol from the mash. Using the evaporation process in the evaporative gas turbine to extract the ethanol from the mash before the distillation step, a lot of energy can be saved. In the evaporation process, the ethanol is extracted directly from the mash using energy from low-level energy sources. The evaporation technology is therefore expected to reduce the cost for the ethanol production. Simultaneous heat and mass transfer inside the ethanol humidification tower drives a mixture of ethanol and water into the compressor discharge air. To investigate the evaporation of a binary mixture into air at elevated pressures and temperatures, a test facility was constructed and integrated into the evaporative gas turbine pilot-plant. The concentration of ethanol in the mash is not constant but depends on the sugar content in the feedstock used in the fermentation process. Tests were therefore conducted at different concentrations of ethanol in the ethanol-water mixture. Tests were also performed at different temperature and flow conditions to establish the influence of these parameters on the lower heating value of the produced low calorific gas. It has been shown that this technology extracts about 80% of the ethanol from the mash. It has also been shown that the composition of the resulting gas depends on the temperatures, flow rates and composition of the incoming streams. The tests have shown that the produced gas has a lower heating value between of 1.8 to 3.8 MJ/kg. The produced gas with heating values in the upper range is possible to use as fuel in the gas turbine without any pilot flame. Initial models of the ethanol humidification process have been established and the initial test results have been used for validating developed models.

scholarly journals Gas Turbine Uses Coal Fuel With Indirect Heat Transfer via Circulating Ceramic Beads

1986 ◽  
Author(s):  
C. E. Jahnig
Keyword(s):  
Power Systems ◽  
Gas Turbine ◽  
Coal Combustion ◽  
Gas Turbines ◽  
Environmental Control ◽  
Petroleum Industry ◽  
Coal Ash ◽  
Coal Fuel ◽  
Intermediate Column ◽  
Minimal Environmental Impact

This paper defines a gas turbine power system in which the heat from coal combustion is transferred to a clean working gas by contact with a recirculated stream of hot ceramic beads. The beads are first heated by direct contact in a pressurized coal combustion zone and then the hot beads are separated, freed of coal ash and contacted directly with a pressurized gas such as air going to a gas turbine. Separate zones are used for combustion and for contact with the clean gas to be heated, and these two zones are kept separated by an intermediate column of beads at each transfer point. Similar technology is well known and used commercially in the petroleum industry, for example, in catalytic cracking of oil to make gasoline. Hot clean gas from the operation is used to generate power in an expander, while the products from coal combustion are handled by conventional methods for environmental control. The system offers the simplicity and efficiency typical of gas turbines and avoids the large use of water typical of steam power systems. Low investment is expected, together with minimal environmental impact.

scholarly journals Simulation of the Heat Transfer in a Gas Turbine Combustor Fueled With Coal-Water Mixture: Part 1 — Model Development and Verification

1986 ◽  
Author(s):  
Ihab H. Farag ◽  
Joseph Vaillancourt
Keyword(s):  
Heat Transfer ◽  
Water Content ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Model Development ◽  
Significant Loss ◽  
Model Verification ◽  
Water Mixture ◽  
Gas Turbine Combustor ◽  
Coal Particles

It is possible to disperse high concentrations of finely pulverized beneficiated coal in water to produce a stable coal-water slurry fuel (CWF). One of the potential applications of CWF is as a fuel in gas turbines. This represents a relatively novel, developing technology. Coal beneficiation to the level needed for gas turbine application (< 1 percent ash) requires fine grinding of the coal particles to less than 15 μm necessitating increase in water content of the slurry to avoid increased CWS viscosity due to the finer particles. The gas turbine cycle is capable of accommodating an increased water content of the fuel without a significant loss in efficiency. The objective of the present study is to develop and verify a computer model to simulate the heat transfer processes taking place in a gas turbine combustor (GTC) burning a CWF. The model predicts the species and the temperature distribution throughout the GTC, the heat flux patterns and the contribution of both convection and radiation to the total heat transfer rate. Model verification includes cases of cold flow without combustion, combustion without heat release, combustion without convection and/or radiation, verification of exchange areas and an overall energy balance check.

Effect of Rim Seal Configuration on Gas Turbine Cavity Sealing in Both Design and Off-Design Conditions

2018 ◽  
Author(s):  
Riccardo Da Soghe ◽  
Cosimo Bianchini ◽  
Mirko Micio ◽  
Jacopo D’Errico ◽  
Francesco Bavassano
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Acoustic Mode ◽  
Operating Conditions ◽  
Geometrical Parameters ◽  
Turbine Wheel ◽  
Sealing Performance ◽  
Secondary Air ◽  
Heavy Duty Gas Turbine

The desired reduction of secondary air consumption of gas turbines is especially challenging when the sealing of stator-rotor cavities is concerned, where it is necessary to guarantee integrity against hot gas ingestion. Sealing and thermal performance of gas turbine stator-rotor cavities are directly dependent on the rim configuration. This paper provides a CFD-based characterization of heavy-duty gas turbine wheel-spaces when dealing with real engine operating conditions and geometries. Focusing on the rim seal configuration, the geometrical arrangement of the ingestion-cavity, the buffer-cavity and the inner cavities were investigated to improve the ingress flow-discouraging behaviour. The study reveals that the most important geometrical parameters affecting the rim sealing effectiveness are those related to the ingestion-cavity. Moreover, an empirical model to predict the stator-rotor cavity sealing performance in off-design conditions was proposed. The model, that consists in an extension of a well-known literature approach, performed well at the analysed operating conditions, confirming to be an excellent tool for the early design phases. Finally, an investigation on the unsteady behaviour of the seal highlights a coupling with an acoustic mode of the cavity, suggesting possible reasons to justify the presence of rotating structures embedded into the cavity flow.

Thermodynamic Property Models for the Simulation of Advanced Wet Cycles

2003 ◽  
Author(s):  
J. Yan ◽  
X. Ji ◽  
M. Jonsson
Keyword(s):  
Thermodynamic Properties ◽  
Thermodynamic Property ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Performance Test ◽  
Elevated Pressure ◽  
Working Fluid ◽  
Water Mixture ◽  
Water Addition ◽  
Cycle Systems

Advanced gas turbine cycles with water or steam addition (i.e., wet cycles) have attracted much interest in recent years and some commercial systems are available. Because water is added into different points of a gas turbine depending on the methods of water addition, the working fluid of gas turbine has been changed to air-water (humid air) mixture at elevated pressure. Thus, the thermodynamic properties of working fluid are different as conventional gas turbines. Accurate calculation models for thermodynamic properties of air-water mixture are of importance for process simulation, and traceable performance test of turbomachinery and heat exchangers in the wet cycle systems. However, the impacts of thermodynamic properties on the simulation of systems and their components have been overlooked. This paper is to present our study and provide a comprehensive comparison of exiting thermodynamic models of air-water mixtures. Different models including ours have been used to calculate some components including compressor, humidification tower, heat exchanger etc. in wet cycles for investigating the impacts of thermodynamic properties on the system performance. It reveals that a careful selection of thermodynamic property model is crucial for the design of cycles. This paper will provide a useful tool for predicting the performance of the system and design of the wet cycle components and systems.

Experimental Characterization of a Micro Gas Turbine Test Rig

2010 ◽  
Author(s):  
Martina Hohloch ◽  
Jan Zanger ◽  
Axel Widenhorn ◽  
Manfred Aigner
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Fluid Dynamic ◽  
Electrical Power ◽  
Test Rig ◽  
Data Set ◽  
Micro Gas Turbine ◽  
Electrical Power Output ◽  
The Impact

For the development of efficient and fuel flexible decentralized power plant concepts a test rig based on the Turbec T100 micro gas turbine is operated at the DLR Institute of Combustion Technology. This paper reports the characterization of the transient operating performance of the micro gas turbine by selected transient maneuvers like start-up, load change and shut-down. The transient maneuvers can be affected by specifying either the electrical power output or the turbine speed. The impact of the two different operation strategies on the behavior of the engine is explained. At selected stationary load points the performance of the gas turbine components is characterized by using the measured thermodynamic and fluid dynamic quantities. In addition the impact of different turbine outlet temperatures on the performance of the gas turbine is worked out. The resulting data set can be used for validation of numerical simulation and as a base for further investigations on micro gas turbines.

scholarly journals Material Characterization of Candidate Silicon Based Ceramics for Stationary Gas Turbine Applications

1995 ◽  
Author(s):  
Vijay M. Parthasarathy ◽  
Jeffrey R. Price ◽  
William D. Brentnall ◽  
George Graves ◽  
Steven Goodrich
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Fatigue Testing ◽  
Composite Ceramics ◽  
Test Bed ◽  
Ceramic Components ◽  
Industrial Gas Turbines ◽  
Improved Performance ◽  
Silicon Based

The Ceramic Stationary Gas Turbine (CSGT) Program is evaluating the potential of using monolithic and composite ceramics in the hot section of industrial gas turbines. Solar Turbine’s Centaur 50 engine is being used as the test bed for ceramic components. The first stage blade, first stage nozzle and the combustor have been selected to develop designs with retrofit potential, which will result in improved performance and lowered emissions. As part of this DOE sponsored initiative a design and life prediction database under relevant conditions is being generated. This paper covers experiments conducted to date on the evaluation of monolithic silicon based ceramics. Mechanical property characterizations have included dynamic fatigue testing of tensile as well as flexural specimens at the temperatures representative of the blade root, the blade airfoil and the nozzle airfoil. Data from subcomponent testing of blade attachment concepts are also included.

Characterization of products from a gas turbine combustor fired directly with coal-water mixture

Fuel ◽  
1987 ◽  
Vol 66 (4) ◽  
pp. 563-567 ◽  
Author(s):  
C SPIRO ◽  
C CHEN ◽  
J WONG ◽  
S KIMURA ◽  
R GREEGOR
Keyword(s):  
Gas Turbine ◽  
Water Mixture ◽  
Gas Turbine Combustor

scholarly journals Behavior of Coal Ash and Alkali Matter in a Coal-Fired Gas Turbine System

1984 ◽  
Author(s):  
R. K. Ahluwalia ◽  
K. H. Im ◽  
C. F. Chuang ◽  
H. K. Geyer ◽  
T. J. O’Brien ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Particle Deposition ◽  
Turbine Blades ◽  
Laboratory Data ◽  
Coal Ash ◽  
Equilibrium Analysis ◽  
Water Mixture ◽  
Aerosol Formation ◽  
Gaseous Species ◽  
Coal Cleaning

The behavior of coal ash and corrosive alkali species in a gas turbine fueled by an ultra-clean coal water mixture (UCCWM) is investigated. A thermochemical equilibrium analysis is first conducted to study the effect of coal cleaning on the extent of vaporization of ash constituents. It is found that for a selected bituminous coal, cleaned up to 10% of the initial ash content, the amount of Ca, Mg, Si and Al vaporized is independent of coal cleaning and that of Na, K and Fe directly proportional to the degree of coal cleaning. In order to study the fate of the vaporized constituents, a gas-to-particle conversion (condensation) model is formulated. The aerosol processes of homogeneous nucleation, heterogeneous nucleation, particle agglomeration, particle deposition, as well as direct vapor deposition on boundary surfaces are included in the formulation. The aerosol formation calculations are driven by the gas phase equilibrium chemistry of twelve elements and twenty seven gaseous species. The model is partially validated by comparison against available laboratory data on ash nucleation in a laminar flow furnace. Application of the model to UCCWM gas turbine system indicates that the characteristic condensation time of sodium and potassium sulfates is much smaller than the residence time in gas turbine, that in spite of the presence of numerous nucleated ash particles the alkali sulfates undergo self-nucleation, and that thermophoresis and Brownian motion are expected to be the primary mechanisms of sulfate deposition on turbine blades.

scholarly journals Experimental Evaluation of a Two-Stage Slagging Combustor Design for a Coal-Fueled Industrial Gas Turbine

1992 ◽  
Author(s):  
L. H. Cowell ◽  
R. T. LeCren
Keyword(s):  
Gas Turbine ◽  
Combustion Zone ◽  
Combustion Process ◽  
Coal Ash ◽  
Pollutant Emissions ◽  
Test Facility ◽  
Inlet Temperature ◽  
Water Mixture ◽  
Test Results ◽  
Industrial Gas Turbine

A full-size combustor for a coal-fueled industrial gas turbine engine has been tested to evaluate combustion performance prior to integration with an industrial gas turbine. The design is based on extensive work completed through one-tenth scale combustion tests. Testing of the combustion hardware is completed with a high pressure air supply in a combustion test facility at the Caterpillar Technical Center. The combustor is a two-staged, rich-lean design. Fuel and air are introduced in the primary combustion zone where the combustion process is initiated. The primary zone operates in a slagging mode inertially removing coal ash from the gas stream. Four injectors designed for coal-water mixture (CWM) atomization are used to introduce the fuel and primary air. In the secondary combustion zone additional air is injected to complete the combustion process at fuel-lean conditions. The secondary zone also serves to reduce the gas temperatures exiting the combustor. The combustor has operated at test pressures of 7 bars with 600K inlet temperature. Tests have been completed to set the air flow split and to map the performance of the combustor as characterized by pollutant emissions, coal ash separation, and temperature profile. Test results with a comparison to subscale test results are discussed. The test results have indicated that the combustor operates at combustion efficiencies above 98% and with pollutant emissions below design goals.

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