Low Emissions Combustion for the Regenerative Gas Turbine: Part 1—Theoretical and Design Considerations

1974 ◽  
Vol 96 (1) ◽  
pp. 32-48 ◽  
Author(s):  
W. R. Wade ◽  
P. I. Shen ◽  
C. W. Owens ◽  
A. F. McLean
Keyword(s):  
Gas Turbine ◽  
Flame Temperature ◽  
Homogeneous System ◽  
Automotive Application ◽  
Inlet Temperature ◽  
Oxides Of Nitrogen ◽  
Turbine Engine ◽  
Homogeneous Combustion ◽  
Hc Emissions ◽  
Model Year

This first part, of a two part paper, reviews the NOx emission problem of the regenerative gas turbine engine for automotive application. It discusses the problem of fuel droplet burning, which causes heterogenous combustion with resulting high flame temperatures and high levels of oxides of nitrogen. The paper proposes means to achieve homogeneous combustion and shows that, even with this approach, flame temperatures need to be closely controlled to effect a compromise between NOx, CO, and HC emissions in order to meet the stringent numerical levels of emissions specified by the Federal standards for 1976 and subsequent model year automobiles. The paper shows that combustor inlet temperature of a homogeneous system has little effect, theoretically, on computed NOx emissions expressed as grams per mile, thereby strengthening the case for the regenerative turbine engine. A design concept for homogeneous combustion with controlled flame temperature is discussed.

Catalytic Combustion Technology Development for Gas Turbine Engine Applications

1998 ◽  
Vol 549 ◽  
Author(s):  
Robert N. Carter ◽  
Lance L. Smith ◽  
Hasan Karim ◽  
Marco Castaldi ◽  
Shah Etemad ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Catalytic Combustion ◽  
Materials Science ◽  
Technology Development ◽  
Flame Temperature ◽  
Oxides Of Nitrogen ◽  
Nox Formation ◽  
Turbine Engine ◽  
Lean Premixed ◽  
Homogeneous Combustion

AbstractCatalytic combustion is one means of meeting increasingly strict emissions requirements for ground-based gas turbine engines for power generation. In conventional homogeneous combustion, high flame temperatures and incomplete combustion lead to emissions of oxides of nitrogen (NOx) and carbon monoxide (CO), and in lean premixed systems unburned hydrocarbons (UHC). However, catalyst-assisted reaction upstream of a lean premixed homogeneous combustion zone can increase the fuel/air mixture reactivity sufficiently to provide low CO/UHC emissions. Additionally, catalytic combustion extends the lean limit of combustion, thereby minimizing NOx formation by lowering the adiabatic flame temperature. An overview of this technology is presented including discussion of the many materials science and catalyst challenges that catalytic combustion poses ranging from the need for high temperature materials to catalyst performance and endurance. Results of ongoing development efforts at Precision Combustion, Inc. (PCI) are presented including modeling studies and experimental results from both bench-scale and combustor-scale studies.

The Effects of Ambient Conditions on Gas Turbine Emissions—Generalized Correction Factors

1978 ◽  
Vol 100 (4) ◽  
pp. 640-646 ◽  
Author(s):  
P. Donovan ◽  
T. Cackette
Keyword(s):  
Gas Turbine ◽  
Pressure Ratio ◽  
Turbine Engines ◽  
Inlet Temperature ◽  
Gas Turbine Engines ◽  
Correction Factors ◽  
Oxides Of Nitrogen ◽  
Ambient Conditions ◽  
Nitrogen Emission ◽  
Wide Range

A set of factors which reduces the variability due to ambient conditions of the hydrocarbon, carbon monoxide, and oxides of nitrogen emission indices has been developed. These factors can be used to correct an emission index to reference day ambient conditions. The correction factors, which vary with engine rated pressure ratio for NOx and idle pressure ratio for HC and CO, can be applied to a wide range of current technology gas turbine engines. The factors are a function of only the combustor inlet temperature and ambient humidity.

Practical Implications of Integrating Turbomachinery Into the Air Turborocket

2004 ◽  
Author(s):  
Joshua A. Clough ◽  
Mark J. Lewis
Keyword(s):  
Gas Turbine ◽  
Aircraft Engine ◽  
Launch Vehicle ◽  
Turbine Engines ◽  
Inlet Temperature ◽  
Gas Turbine Engines ◽  
Turbine Inlet Temperature ◽  
Turbine Engine ◽  
Space Launch ◽  
Practical Implications

The development of new reusable space launch vehicle concepts has lead to the need for more advanced engine cycles. Many two-stage vehicle concepts rely on advanced gas turbine engines that can propel the first stage of the launch vehicle from a runway up to Mach 5 or faster. One prospective engine for these vehicles is the Air Turborocket (ATR). The ATR is an innovative aircraft engine flowpath that is intended to extend the operating range of a conventional gas turbine engine. This is done by moving the turbine out of the core engine flow, alleviating the traditional limit on the turbine inlet temperature. This paper presents the analysis of an ATR engine for a reusable space launch vehicle and some of the practical problems that will be encountered in the development of this engine.

Design, Analysis, and Manufacture of an Axial Length-Saving Disk-Oriented Engine

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Bennett M. Staton ◽  
Brian T. Bohan ◽  
Marc D. Polanka ◽  
Larry P. Goss
Keyword(s):  
Gas Turbine ◽  
Axial Length ◽  
Electric Propulsion ◽  
Guide Vane ◽  
Combustion Process ◽  
Gas Turbine Engine ◽  
Inlet Temperature ◽  
Turbine Engine ◽  
Power Extraction ◽  
Turbine Inlet

Abstract A disk-oriented engine was designed to reduce the overall length of a gas turbine engine, combining a single-stage centrifugal compressor and radial in-flow turbine (RIT) in a back-to-back configuration. The focus of this research was to understand how this unique flow path impacted the combustion process. Computational analysis was accomplished to determine the feasibility of reducing the axial length of a gas turbine engine utilizing circumferential combustion. The desire was to maintain circumferential swirl from the compressor through a U-bend combustion path. The U-bend reverses the outboard flow from the compressor into an integrated turbine guide vane in preparation for power extraction by the RIT. The computational targets for this design were a turbine inlet temperature of 1300 K, operating with a 3% total pressure drop across the combustor, and a turbine inlet pattern factor (PF) of 0.24 to produce a cycle capable of creating 668 N of thrust. By wrapping the combustion chamber about the circumference of the turbomachinery, the axial length of the entire engine was reduced. Reallocating the combustor volume from the axial to radial orientation reduced the overall length of the system up to 40%, improving the mobility and modularity of gas turbine power in specific applications. This reduction in axial length could be applied to electric power generation for both ground power and airborne distributive electric propulsion. Computational results were further compared to experimental velocity measurements on custom fuel–air swirl injectors at mass flow conditions representative of 668 N of thrust, providing qualitative and quantitative insight into the stability of the flame anchoring system. From this design, a full-scale physical model of the disk-oriented engine was designed for combustion analysis.

Performance Seeking Control of Regenerative Gas Turbine Engines

2000 ◽  
Author(s):  
Nanahisa Sugiyama
Keyword(s):  
Gas Turbine ◽  
Turbine Engines ◽  
Inlet Temperature ◽  
Gas Turbine Engines ◽  
Efficiency Enhancement ◽  
Turbine Inlet Temperature ◽  
Control Variables ◽  
Turbine Engine ◽  
Selection Of ◽  
Engine Life

A Performance Seeking Control (PSC) can realize the operations advantageous enough to accomplish the economy, safety, engine life, and environmental issues by reducing the control margin to the extremity together with selection of the control variables so that various kinds of parameters will be minimized or maximized. This paper describes the results obtained from the simulation study concerning the PSC aiming at the efficiency enhancement, power improvement, and longer engine life of a two-spool regenerative gas turbine engine having two control variables. By constructing the dynamic simulation of the engine, steady-state characteristics and dynamic characteristics are derived; then, a PSC system is designed and evaluated. It is concluded that the PSC for the gas turbine of this type can be realized by the turbine inlet temperature control.

The AGT101 Advanced Automotive Gas Turbine

1982 ◽  
Author(s):  
R. A. Rackley ◽  
J. R. Kidwell
Keyword(s):  
United States ◽  
Gas Turbine ◽  
The United States ◽  
Gas Turbine Engine ◽  
Development Project ◽  
Single Stage ◽  
Department Of Energy ◽  
Inlet Temperature ◽  
United States Department ◽  
Turbine Engine

The Garrett/Ford Advanced Gas Turbine Powertrain System Development Project, authorized under NASA Contract DEN3-167, is sponsored by and is part of the United States Department of Energy Gas Turbine Highway Vehicle System Program. Program effort is oriented at providing the United States automotive industry the technology base necessary to produce gas turbine powertrains competitive for automotive applications having: (1) reduced fuel consumption, (2) multi-fuel capability, and (3) low emissions. The AGT101 powertrain is a 74.6 kW (100 hp), regenerated single-shaft gas turbine engine operating at a maximum turbine inlet temperature of 1644 K (2500 °F), coupled to a split differential gearbox and Ford automatic overdrive production transmission. The gas turbine engine has a single-stage centrifugal compressor and a single-stage radial inflow turbine mounted on a common shaft. Maximum rotor speed is 10,472 rad/sec (100,000 rpm). All high-temperature components, including the turbine rotor, are ceramic. AGT101 powertrain development has been initiated, with testing completed on many aerothermodynamic components in dedicated test rigs and start of Mod I, Build 1 engine testing.

Analysis of Indirectly Fired Gas Turbine Power Systems

2007 ◽  
Author(s):  
J. E. Donald Gauthier
Keyword(s):  
Power Generation ◽  
Power Systems ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Turbine Engines ◽  
Inlet Temperature ◽  
Turbine Engine ◽  
Engine Design ◽  
Wide Range ◽  
System Configurations

This paper describes the results of modelling the performance of several indirectly fired gas turbine (IFGT) power generation system configurations based on four gas turbine class sizes, namely 5 kW, 50 kW, 5 MW and 100 MW. These class sizes were selected to cover a wide range of installations in residential, commercial, industrial and large utility power generation installations. Because the IFGT configurations modelled consist of a gas turbine engine, one or two recuperators and a furnace; for comparison purpose this study also included simulations of simple cycle and recuperated gas turbine engines. Part-load, synchronous-speed simulations were carried out with generic compressor and turbine maps scaled for each engine design point conditions. The turbine inlet temperature (TIT) was varied from the design specification to a practical value for a metallic high-temperature heat exchanger in an IFGT system. As expected, the results showed that the reduced TIT can have dramatic impact on the power output and thermal efficiency when compared to that in conventional gas turbines. However, the simulations also indicated that several configurations can lead to higher performance, even with the reduced TIT. Although the focus of the study is on evaluation of thermodynamic performance, the implications of varying configurations on cost and durability are also discussed.

Full-Annulus URANS Study on the Transportation of Combustion Inhomogeneity in a Four-Stage Cooled Turbine

2019 ◽  
Author(s):  
Zhongran Chi ◽  
Haiqing Liu ◽  
Shusheng Zang ◽  
Chengxiong Pan ◽  
Guangyun Jiao
Keyword(s):  
Gas Turbine ◽  
Gas Turbine Engine ◽  
Rotor Blades ◽  
Inlet Temperature ◽  
Computational Domain ◽  
Temperature Inhomogeneity ◽  
Unsteady Temperature ◽  
Turbine Engine ◽  
Exhaust Temperature ◽  
The Time Domain

Abstract The inhomogeneity of temperature in a turbine is related to the nonuniform heat release and air injections in combustors. In addition, it is influenced by the interactions between turbine cascades and coolant injections. Temperature inhomogeneity results in nonuniform flow temperature at turbine outlets, which is commonly measured by multiple thermal couples arranged in the azimuthal direction to monitor the operation of a gas turbine engine. Therefore, the investigation of temperature inhomogeneity transportation in a multistage gas turbine should help in detecting and quantifying the over-temperature or flameout of combustors using turbine exhaust temperature. Here the transportation of temperature inhomogeneity inside the four-stage turbine of a 300-MW gas turbine engine was numerically investigated using 3D CFD. The computational domain included all four stages of the turbine, consisting of more than 500 blades and vanes. Realistic components (N2, O2, CO2, and H2O) with variable heat capacities were considered for hot gas and cooling air. Coolants were added to the computational domain through more than 19,000 mass and momentum source terms. his was simple compared to realistic cooling structures. A URANS CFD run with over-temperature/flameout at 6 selected combustors out of 24 was carried out. The temperature distributions at rotor–stator interfaces and the turbine outlet were quantified and characterized by Fourier transformations in the time domain and space domain. It is found that the transport process from the hot-streaks/cold-streaks at the inlet to the outlet is relatively stable. The cold and hot fluid is redistributed in time and space due to the stator and rotor blades, in the region with a large parameter gradient at the inlet, strong unsteady temperature field and composition field appear. The distribution of the exhaust gas composition has a stronger correlation with the inlet temperature distribution and is less susceptible to interference.

Improved Gas Turbine Efficiency Through Alternative Regenerator Configuration

2002 ◽  
Author(s):  
Paul A. Dellenback
Keyword(s):  
Gas Turbine ◽  
Operating Conditions ◽  
Cycle Performance ◽  
Inlet Temperature ◽  
Optimum Pressure ◽  
Model Calculations ◽  
Turbine Engine ◽  
Combustion Gases ◽  
Wide Range ◽  
Temperature Combustion

An alternative configuration for a regenerative gas turbine engine cycle is presented that yields higher cycle efficiencies than either simple or conventional regenerative cycles operating under the same conditions. The essence of the scheme is to preheat compressor discharge air with high temperature combustion gases before the latter are fully expanded across the turbine. The efficiency is improved because air enters the combustor at a higher temperature, and hence heat addition in the combustor occurs at a higher average temperature. The heat exchanger operating conditions are more demanding than for a conventional regeneration configuration, but well within the capability of modern heat exchangers. Models of cycle performance exhibit several percentage points of improvement relative to either simple cycles or conventional regeneration schemes. The peak efficiencies of the alternative regeneration configuration occur at optimum pressure ratios that are significantly lower than those required for the simple cycle. For example, at a turbine inlet temperature of 1300°C (2370°F), the alternative regeneration scheme results in cycle efficiencies of 50% for overall pressure ratios of 22, whereas simple cycles operating at the same temperature would yield efficiencies of only 43.8% at optimum pressure ratios of 50, which are not feasible with current compressor designs. Model calculations for a wide range of parameters are presented, as are comparisons with simple and conventional regeneration cycles.

Steady and Dynamic Performance and Emissions of a Variable Geometry Combustor in a Gas Turbine Engine

2002 ◽  
Author(s):  
Y. G. Li ◽  
R. L. Hales
Keyword(s):  
Gas Turbine ◽  
Dynamic Performance ◽  
Flame Temperature ◽  
Combustion Efficiency ◽  
Operating Conditions ◽  
Variable Geometry ◽  
Turbofan Engine ◽  
Turbine Engine ◽  
Control Schemes ◽  
Fuel Staging

One of the remedies to reduce the major emissions production of nitric oxide (NOx), carbon monoxide (CO) and unburned hydrocarbon (UHC) from conventional gas turbine engine combustors at both high and low operating conditions without losing its performance and stability is to use variable geometry combustors. This type of combustor configuration provides the possibility of dynamically controlling the airflow distribution of the combustor based on its operating conditions and therefore controlling the combustion in certain lean burn conditions. Two control schemes are described and analyzed in this paper: both are based on airflow control with variable geometry, the second including fuel staging. A model two-spool turbofan engine is chosen in this study to test the effectiveness of the variable geometry combustor and control schemes. The steady and dynamic performance of the turbofan engine is simulated and analyzed using an engine transient performance analysis code implemented with the variable geometry combustor. Empirical correlations for NOx, CO and UHC are used for the estimation of emissions. Some conclusions are obtained from this study: • With variable geometry combustors significant reduction of NOx emissions at high operating conditions and CO and UHC at low operating condition is possible; • Combustion efficiency and stability can be improved at low operating conditions, which is symbolized by the higher flame temperature in the variable geometry combustor; • The introduced correlation between non-dimensional fuel flow rate and air flow ratio to the primary zone is effective and simple in the control of flame temperature; • Circumferential fuel staging can reduce the range of air splitter movement in most of the operating conditions from idle to maximum power and have the great potential to reduce the inlet distortion to the combustor and improve the combustion efficiency; • During transient processes, the maximum moving rate of the hydraulic driven system may delay the air splitter movement but this effect on engine combustor performance is not significant.

Sign in / Sign up

Export Citation Format

Share Document