scholarly journals Effect of Gas and Metal Temperatures on Gas Turbine Deposition

1982 ◽  
Author(s):  
Arthur Cohn
Keyword(s):  
Gas Turbine ◽  
Deposition Rate ◽  
Maximum Rate ◽  
Combustion Products ◽  
Metal Temperature ◽  
Residual Oil ◽  
Gas Temperature ◽  
Deposition Rates ◽  
Type Fuel ◽  
Oil Type

A number of test projects have measured the deposition rates of the combustion products of residual-oil-type fuel. This paper analyzes those results to obtain information on he effects of the gas and metal temperatures on the deposition rates. While the data is far from complete, certain major trends result from the data. For a given gas temperature, the deposition rate increases with decreasing metal temperature below the level of the gas temperature until a maximum rate is reached at ∼1200°F (650°C); then the deposition rate decreases as the metal temperature is further lowered and becomes small at metal temperatures near 700°F (370°C). For a given metal temperature, the deposition rate increases with higher gas temperatures. This may occur at an increasing rate for gas temperatures above 2000°F (1100°C).

scholarly journals Physical Aspects of Deposition From Coal Water Fuels Under Gas Turbine Conditions

1989 ◽  
Author(s):  
Richard A. Wenglarz ◽  
Ralph G. Fox
Keyword(s):  
Gas Turbine ◽  
Combustion Products ◽  
Control Measures ◽  
Unburned Carbon ◽  
Test Results ◽  
Gas Temperature ◽  
Hot Gas ◽  
Stators And Rotors ◽  
Temperature Surface ◽  
Deposition Control

Deposition, erosion, and corrosion (DEC) experiments were conducted using three coal-water fuels (CWF) in a staged subscale turbine combustor operated at conditions of a recuperated turbine. This rich-quench-lean (RQL) combustor appears promising for reducing NOx levels to acceptable levels for future turbines operating with CWF. Specimens were exposed in two test sections to the combustion products from the RQL combustor. The gas and most surface temperatures in the first and second test sections represented temperatures in the first stators and rotors, respectively, of a recuperated turbine. The test results indicate deposition is affected substantially by gas temperature, surface temperature, and unburned carbon due to incomplete combustion. The high rates of deposition observed at first stator conditions showed the need for additional tests to identify CWF coals with lower deposition tendencies and to explore deposition control measures such as hot gas cleanup.

Physical Aspects of Deposition From Coal-Water Fuels Under Gas Turbine Conditions

1990 ◽  
Vol 112 (1) ◽  
pp. 9-14 ◽  
Author(s):  
R. A. Wenglarz ◽  
R. G. Fox
Keyword(s):  
Gas Turbine ◽  
Combustion Products ◽  
Control Measures ◽  
Unburned Carbon ◽  
Test Results ◽  
Gas Temperature ◽  
Hot Gas ◽  
Stators And Rotors ◽  
Temperature Surface ◽  
Deposition Control

Deposition, erosion, and corrosion (DEC) experiments were conducted using three coal-water fuels (CWF) in a staged subscale turbine combustor operated at conditions of a recuperated turbine. This rich-quench-lean (RQL) combustor appears promising for reducing NOx levels to acceptable levels for future turbines operating with CWF. Specimens were exposed in two test sections to the combustion products from the RQL combustor. The gas and most surface temperatures in the first and second test sections represented temperatures in the first stators and rotors, respectively, of a recuperated turbine. The test results indicate deposition is affected substantially by gas temperature, surface temperature, and unburned carbon due to incomplete combustion. The high rates of deposition observed at first stator conditions showed the need for additional tests to identify CWF coals with lower deposition tendencies and to explore deposition control measures such as hot gas cleanup.

scholarly journals АНАЛИТИЧЕСКОЕ ОПРЕДЕЛЕНИЕ ИСТИННОЙ УДЕЛЬНОЙ ИЗОБАРНОЙ ТЕПЛОЁМКОСТИ КОМПОНЕНТ ВОЗДУХА И ПРОДУКТОВ СГОРАНИЯ С УЧЁТОМ ВЛИЯНИЯ ТЕМПЕРАТУРЫ И ДАВЛЕНИЯ И ЭФФЕКТА ТЕРМИЧЕСКОЙ ДИССОЦИАЦИИ

2019 ◽  
pp. 4-17
Author(s):  
Майя Владимировна Амброжевич ◽  
Михаил Анатольевич Шевченко
Keyword(s):  
Heat Capacity ◽  
Gas Turbine ◽  
Pressure Ratio ◽  
Thermal Dissociation ◽  
Combustion Products ◽  
Heat Capacities ◽  
Isobaric Heat Capacity ◽  
Working Fluid ◽  
Gas Temperature ◽  
Temperature And Pressure

The basic thermophysical parameter of the working fluid of all thermal machines without exception is isobaric heat capacity (specific heat at constant pressure). Traditionally, in engineering calculations of isobaric heat capacity are determined as a tabular value for average heat capacities, or approximated with a square parabola within a given temperature range. Isobaric heat capacity is a function of temperature only. At the current level of GTE development, when the overall compressor pressure ratio is already up to 50 and the tendency of its increase remains it is unacceptable to neglect the pressure. However, the turbine inlet gas temperature also rises that will inevitably lead to the effect of thermal dissociation in the combustion products of the gas turbine engine. The studies of the thermal dissociation effect influence on the parameters of the working process of advanced GTE show that this ignoring leads to computational errors. At the present time, there are mathematical models that allow calculating the isobaric heat capacity as a function of temperature and pressure (taking into account the effect of thermal dissociation) but they are laborious, which is not always practical when estimate calculations performing and program algorithms writing. Consequently, the authors posed the problem of obtaining of simple analytic relationships that make it possible to calculate the isobaric heat capacity as a function of temperature and pressure (taking into account the effect of thermal dissociation). Based on the tabular data for the main components of the gas turbine combustion products within a given range of pressures and temperatures (nitrogen: p = 1 ... 200 bar, T = 150 ... 2870 K, oxygen: p = 1 ... 200 bar, T = 210 ... 2870 K, argon: p = 1 ... 200 bar, T = 190 ... 1300 K, the water vapor: p = 0.1 ... 200 bar, T = 640 ... 1250 K and p = 0.1 ... 400 bar and T = 1250 ... 3200 K, carbon dioxide: p = 1 ... 200 bar, T = 390 ... 2600 K), analytical dependencies were obtained for the calculation of isobaric heat capacities as functions of temperature and pressure taking into account the effect of thermal dissociation. The results of the calculations were compared with tabulated experimental data.

Fundamental Impact of Firing Syngas in Gas Turbines

2007 ◽  
Author(s):  
Emmanuel O. Oluyede ◽  
Jeffrey N. Phillips
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Hydrogen Content ◽  
Firing Temperature ◽  
Power Output ◽  
Gas Turbines ◽  
Combustion Products ◽  
Metal Temperature ◽  
Turbine Component ◽  
The Impact

This paper addresses the impact of burning syngas in a large size, heavy-duty gas turbine designed to run on natural gas while maintaining hot section life. The process used to produce syngas is not discussed here; we mainly focus on analyzing the issues related to switching from natural gas to syngas on the gas turbine hot sections and the possibility of reducing the firing temperature in order to maintain the durability of the hot metal section life. The analysis indicate that the power output for a syngas-fired turbine plant could be increased as much as 20–25% when compared with the same turbine fired at the same metal temperature as the natural gas, however this increase in power output is also accompanied by an increase in the moisture content of the combustion products due largely to higher hydrogen content in the syngas and the increased turbine flow which contribute significantly to the overheating of turbine component parts. Correlations based on the hydrogen content as well as the lower heating value of the fuels were obtained in order to determine specific firing temperature reduction necessary to obtain durable metal temperature.

Performance Assessment of a Prototype Trapped Vortex Combustor Concept for Gas Turbine Application

2001 ◽  
Author(s):  
D. L. Burrus ◽  
A. W. Johnson ◽  
W. M. Roquemore ◽  
D. T. Shouse
Keyword(s):  
Gas Turbine ◽  
Combustion Efficiency ◽  
Operating Conditions ◽  
Gas Temperature ◽  
Test Rig ◽  
Turbine Engine ◽  
Run Time ◽  
K 12 ◽  
Trapped Vortex ◽  
Type Fuel

GE Aircraft Engines and the Air Force Research Laboratory have been jointly developing a novel combustor technology concept for potential application in gas turbine engines. This novel combustor concept is known as the Trapped Vortex Combustor (TVC). The GE and AFRL team began work on the design of a prototypical TVC test rig in 1996. This effort represents the extension of earlier AFRL research with the TVC [1,2]. This work led to the fabrication of a 30.5 cm wide rectangular sector test rig capable of operation at inlet pressures up to 20.5 atmospheres, inlet temperatures up to 900 K, and to stoichiometric discharge conditions. Testing of the rectangular sector rig was initiated in mid year 1998. The performance evaluation performed on the test rig covered all aspects of gas turbine combustor performance and operability including ground start ignition, lean blowout, altitude re-light, emissions, combustion efficiency, exit gas temperature profile, and structural metal temperatures. Test rig operating conditions provided simulations of current commercial and military aircraft gas turbine engine cycles as well as some advanced engine cycles, with JP-8 type fuel. Data was also obtained at selected operating conditions for the LM2500 marine Navy duty cycle using DL-1 type fuel. The prototype rig has been operated for a total of approximately 300 run hours. 60 hours of run time at pressures exceeding 13.6 atmospheres and temperatures exceeding 675 K. 12 hours of run time at pressures exceeding 15.3 atmospheres, temperatures exceeding 780 K. Over 700 data points were obtained. The assessment of the demonstrated performance revealed the prototype TVC test rig had exceeded all initial expectations. Demonstrated ignition, blow out, and altitude re-light were up to 50% improved over current technology conventional swirl stabilized combustors. NOx emissions were in the range from 40% to 60% of the 1996 ICAO standard. Combustion efficiency at or above 99% was maintained over a 40% wider operating range than a conventional combustor. The performance and operability achieved with this prototype test rig has clearly demonstrated the validity and potential performance payoffs of the TVC concept. This paper will summarize the TVC rectangular sector test rig configurations evaluated as part of this test program, and the performance and operability achieved.

Numerical investigation of non-uniform flow in twin-silo combustors and impact on axial turbine stage performance

2021 ◽  
pp. 095765092199394
Author(s):  
Hafiz M Hassan ◽  
Adeel Javed ◽  
Asif H Khoja ◽  
Majid Ali ◽  
Muhammad B Sajid
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Internal Flow ◽  
Large Temperature ◽  
Clear Understanding ◽  
Gas Temperature ◽  
Turbine Stage ◽  
Flow Angle ◽  
Axial Turbine ◽  
Stage Performance

A clear understanding of the flow characteristics in the older generation of industrial gas turbines operating with silo combustors is important for potential upgrades. Non-uniformities in the form of circumferential and radial variations in internal flow properties can have a significant impact on the gas turbine stage performance and durability. This paper presents a comprehensive study of the underlying internal flow features involved in the advent of non-uniformities from twin-silo combustors and their propagation through a single axial turbine stage of the Siemens v94.2 industrial gas turbine. Results indicate the formation of strong vortical structures alongside large temperature, pressure, velocity, and flow angle deviations that are mostly located in the top and bottom sections of the turbine stage caused by the excessive flow turning in the upstream tandem silo combustors. A favorable validation of the simulated exhaust gas temperature (EGT) profile is also achieved via comparison with the measured data. A drop in isentropic efficiency and power output equivalent to 2.28% points and 2.1 MW, respectively is observed at baseload compared to an ideal straight hot gas path reference case. Furthermore, the analysis of internal flow topography identifies the underperforming turbine blading due to the upstream non-uniformities. The findings not only have implications for the turbine aerothermodynamic design, but also the combustor layout from a repowering perspective.

scholarly journals Fabrication and Mechanical Properties of Cr2AlC MAX Phase Coatings on TiBw/Ti6Al4V Composite Prepared by HiPIMS

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 826
Author(s):  
Muhammad Waqas Qureshi ◽  
Xinxin Ma ◽  
Guangze Tang ◽  
Bin Miao ◽  
Junbo Niu
Keyword(s):  
Magnetron Sputtering ◽  
Deposition Rate ◽  
Pulse Width ◽  
Average Power ◽  
Max Phase ◽  
Ex Situ ◽  
Gas Temperature ◽  
Degree Of Ionization ◽  
Force Microscopy ◽  
High Degree

The high-power impulse magnetron sputtering (HiPIMS) technique is widely used owing to the high degree of ionization and the ability to synthesize high-quality coatings with a dense structure and smooth morphology. However, limited efforts have been made in the deposition of MAX phase coatings through HiPIMS compared with direct current magnetron sputtering (DCMS), and tailoring of the coatings’ properties by process parameters such as pulse width and frequency is lacking. In this study, the Cr2AlC MAX phase coatings are deposited through HiPIMS on network structured TiBw/Ti6Al4V composite. A comparative study was made to investigate the effect of average power by varying frequency (1.2–1.6 kHz) and pulse width (20–60 μs) on the deposition rate, microstructure, crystal orientation, and current waveforms of Cr2AlC MAX phase coatings. X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM) were used to characterize the deposited coatings. The influence of pulse width was more profound than the frequency in increasing the average power of HiPIMS. The XRD results showed that ex situ annealing converted amorphous Cr-Al-C coatings into polycrystalline Cr2AlC MAX phase. It was noticed that the deposition rate, gas temperature, and roughness of Cr2AlC coatings depend on the average power, and the deposition rate increased from 16.5 to 56.3 nm/min. Moreover, the Cr2AlC MAX phase coatings produced by HiPIMS exhibits the improved hardness and modulus of 19.7 GPa and 286 GPa, with excellent fracture toughness and wear resistance because of dense and column-free morphology as the main characteristic.

Experimental Study of a 200 kW Partial Oxidation Gas Turbine (POGT) for Co-Production of Power and Hydrogen-Enriched Fuel Gas

2009 ◽  
Author(s):  
Joseph Rabovitser ◽  
Stan Wohadlo ◽  
John M. Pratapas ◽  
Serguei Nester ◽  
Mehmet Tartan ◽  
...  
Keyword(s):  
Experimental Study ◽  
Gas Turbine ◽  
Partial Oxidation ◽  
Synthesis Gas ◽  
Combustion Products ◽  
Working Fluid ◽  
Fuel Gas ◽  
Lean Combustion ◽  
Start Up ◽  
Oxidation Reactor

Paper presents the results from development and successful testing of a 200 kW POGT prototype. There are two major design features that distinguish POGT from a conventional gas turbine: a POGT utilizes a partial oxidation reactor (POR) in place of a conventional combustor which leads to a much smaller compressor requirement versus comparably rated conventional gas turbine. From a thermodynamic perspective, the working fluid provided by the POR has higher specific heat than lean combustion products enabling the POGT expander to extract more energy per unit mass of fluid. The POGT exhaust is actually a secondary fuel gas that can be combusted in different bottoming cycles or used as synthesis gas for hydrogen or other chemicals production. Conversion steps for modifying a 200 kW radial turbine to POGT duty are described including: utilization of the existing (unmodified) expander; replacement of the combustor with a POR unit; introduction of steam for cooling of the internal turbine structure; and installation of a bypass air port for bleeding excess air from the compressor discharge because of 45% reduction in combustion air requirements. The engine controls that were re-configured for start-up and operation are reviewed including automation of POGT start-up and loading during light-off at lean condition, transition from lean to rich combustion during acceleration, speed control and stabilization under rich operation. Changes were implemented in microprocessor-based controllers. The fully-integrated POGT unit was installed and operated in a dedicated test cell at GTI equipped with extensive process instrumentation and data acquisition systems. Results from a parametric experimental study of POGT operation for co-production of power and H2-enriched synthesis gas are provided.

Modeling of Gas Turbine Fuel Nozzle Spray

1997 ◽  
Vol 119 (1) ◽  
pp. 34-44 ◽  
Author(s):  
N. K. Rizk ◽  
J. S. Chin ◽  
M. K. Razdan
Keyword(s):  
Gas Turbine ◽  
Fuel Injection ◽  
Near Field ◽  
Continuous Phase ◽  
Liquid Sheet ◽  
Vapor Concentration ◽  
Fuel Vapor ◽  
Fuel Injector ◽  
Gas Temperature ◽  
Sheet Breakup

Satisfactory performance of the gas turbine combustor relies on the careful design of various components, particularly the fuel injector. It is, therefore, essential to establish a fundamental basis for fuel injection modeling that involves various atomization processes. A two-dimensional fuel injection model has been formulated to simulate the airflow within and downstream of the atomizer and address the formation and breakup of the liquid sheet formed at the atomizer exit. The sheet breakup under the effects of airblast, fuel pressure, or the combined atomization mode of the airassist type is considered in the calculation. The model accounts for secondary breakup of drops and the stochastic Lagrangian treatment of spray. The calculation of spray evaporation addresses both droplet heat-up and steady-state mechanisms, and fuel vapor concentration is based on the partial pressure concept. An enhanced evaporation model has been developed that accounts for multicomponent, finite mass diffusivity and conductivity effects, and addresses near-critical evaporation. The presents investigation involved predictions of flow and spray characteristics of two distinctively different fuel atomizers under both nonreacting and reacting conditions. The predictions of the continuous phase velocity components and the spray mean drop sizes agree well with the detailed measurements obtained for the two atomizers, which indicates the model accounts for key aspects of atomization. The model also provides insight into ligament formation and breakup at the atomizer exit and the initial drop sizes formed in the atomizer near field region where measurements are difficult to obtain. The calculations of the reacting spray show the fuel-rich region occupied most of the spray volume with two-peak radial gas temperature profiles. The results also provided local concentrations of unburned hydrocarbon (UHC) and carbon monoxide (CO) in atomizer flowfield, information that could support the effort to reduce emission levels of gas turbine combustors.

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