Low-Emissions Gas Turbine Combustor Development for Regional-Class Aircraft

Author(s):  
J. Zelina ◽  
P. F. Penko

Sector-rig test results of four combustor configurations for medium-sized, gas-turbine engines are presented. The sector test section consists of a three-injector combustor cross-section, unrolled to a rectangular area, and simulating about a sixty-eight degree section of the combustor. Performance and emissions data are presented for four design-of-experiment (DOE) combinations of 1) air swirlers, 2) fuel injectors, and 3) primary-zone lengths. Emission concentrations from gas sampling are given for NOx, CO, and UHC as a function of inlet temperature, pressure, and overall fuel air ratio. NOx production as a function of inlet temperature, pressure, stoichiometry, and residence time are presented. The trade-off between NOx and CO is given over a range of operating conditions for each sector configuration.

1978 ◽  
Vol 100 (4) ◽  
pp. 640-646 ◽  
Author(s):  
P. Donovan ◽  
T. Cackette

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.


Author(s):  
C. P. Lea˜o ◽  
S. F. C. F. Teixeira ◽  
A. M. Silva ◽  
M. L. Nunes ◽  
L. A. S. B. Martins

In recent years, gas-turbine engines have undergone major improvements both in efficiency and cost reductions. Several inexpensive models are available in the range of 30 to 250 kWe, with electrical efficiencies already approaching 30%, due to the use of a basic air-compressor associated to an internal air pre-heater. Gas-turbine engines offer significant advantages over Diesel or IC engines, particularly when Natural Gas (NG) is used as fuel. With the current market trends toward Distributed Generation (DG) and the increased substitution of boilers by NG-fuelled cogeneration installations for CO2 emissions reduction, small-scale gas turbine units can be the ideal solution for energy systems located in urban areas. A numerical optimization method was applied to a small-scale unit delivering 100 kW of power and 0.86 kg/s of water, heated from 318 to 353K. In this academic study, the unit is based on a micro gas-turbine and includes an internal pre-heater, typical of these low pressure-ratio turbines, and an external heat recovery system. The problem was formulated as a non-linear optimisation model with the minimisation of costs subject to the physical and thermodynamic constraints. Despite difficulties in obtaining data for some of the components cost-equations, the preliminary results indicate that the optimal compressor pressure ratio is about half of the usual values found in large installations, but higher than those of the currently available micro-turbine models, while the turbine inlet temperature remains virtually unchanged.


Author(s):  
Sanjay ◽  
Onkar Singh ◽  
B. N. Prasad

This paper deals with the thermodynamic performance of complex gas turbine cycles involving inter-cooling, re-heating and regeneration. The performance has been evaluated based on the mathematical modeling of various elements of gas turbine for the real situation. The fuel selected happens to be natural gas and the internal convection / film / transpiration air cooling of turbine bladings have been assumed. The analysis has been applied to the current state-of-the-art gas turbine technology and cycle parameters in four classes: Large industrial, Medium industrial, Aero-derivative and Small industrial. The results conform with the performance of actual gas turbine engines. It has been observed that the plant efficiency is higher at lower inter-cooling (surface), reheating and regeneration yields much higher efficiency and specific power as compared to simple cycle. There exists an optimum overall compression ratio and turbine inlet temperature in all types of complex configuration. The advanced turbine blade materials and coating withstand high blade temperature, yields higher efficiency as compared to lower blade temperature materials.


Author(s):  
Joshua A. Clough ◽  
Mark J. Lewis

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.


Author(s):  
J. M. Lane

While the radial in-flow turbine has consistently demonstrated its capability as a high-performance component for small gas turbine engines, its use has been relegated to lower turbine-inlet-temperature cycles due to insurmountable problems with respect to the manufacturing of radial turbine rotors with internal cooling passages. These cycle temperature limitations are not consistent with modern trends toward higher-performance, fuel-conservative engines. This paper presents the results of several Army-sponsored programs, the first of which addresses the performance potential for the high-temperature radial turbine. The subsequent discussion presents the results of two successful programs dedicated to developing fabrication techniques for internally cooled radial turbines, including mechanical integrity testing. Finally, future near-term capabilities are projected.


Author(s):  
Kozi Nishio ◽  
Junzo Fujioka ◽  
Tetsuo Tatsumi ◽  
Isashi Takehara

With the aim of achieving higher efficiency, lower pollutant emissions, and multi-fuel capability for small to medium-sized gas turbine engines for use in co-generation systems, a ceramic gas turbine (CGT) research and development program is being promoted by the Japanese Ministry of International Trade and Industry (MITI) as a part of its “New Sunshine Project”. Kawasaki Heavy Industries (KHI) is participating in this program and developing a regenerative two-shaft CGT (CGT302). In 1993, KHI conducted the first test run of an engine with full ceramic components. At present, the CGT302 achieves 28.8% thermal efficiency at a turbine inlet temperature (TIT) of 1117°C under ISO standard conditions and an actual TIT of 1250°C has been confirmed at the rated speed of the basic CGT. This paper consists of the current state of development of the CGT302 and how ceramic components are applied.


Author(s):  
Nanahisa Sugiyama

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.


Author(s):  
John Blouch ◽  
Hejie Li ◽  
Mark Mueller ◽  
Richard Hook

The LM2500 and LM6000 dry-low-emissions aeroderivative gas turbine engines have been in commercial service for 15 years and have accumulated nearly 10 × 106 hours of commercial operation. The majority of these engines utilize pipeline quality natural gas predominantly comprised of methane. There is; however, increasing interest in nonstandard fuels that contain varying levels of higher hydrocarbon species and/or inert gases. This paper reports on the demonstrated operability of LM2500 and LM6000 DLE engines with nonstandard fuels. In particular, rig tests at engine conditions were performed to demonstrate the robustness of the dual-annular counter-rotating swirlers premixer design, relative to flameholding with fuels containing high ethane, propane, and N2 concentrations. These experiments, which test the ability of the hardware to shed a flame introduced into the premixing region, have been used to expand the quoting limits for LM2500 and LM6000 gas turbine engines to elevated C2+ levels. In addition, chemical kinetics analysis was performed to understand the effect of temperature, pressure, and fuel compositions on flameholding. Test data for different fuels and operating conditions were successfully correlated with Damkohler number.


Author(s):  
Jeffrey S. Patterson ◽  
Soren K. Spring

The Landing Craft Air Cushion (LCAC) gas turbine engines operate in an extremely harsh environment and are exposed to excessive amounts of foreign contaminants. The present method of crank washing is effective when properly performed, but is labor intensive and increases craft downtime. Naval Ship Systems Engineering Station (NAVSSES) designed and installed a prototype on-line detergent wash system which reduced maintenance and craft downtime. Initial test results indicated that the system reduced engine performance degradation and corrosion.


1967 ◽  
Vol 89 (2) ◽  
pp. 177-185 ◽  
Author(s):  
M. J. T. Smith ◽  
M. E. House

The noise sources from gas turbine engines are defined and their radiation patterns identified from test results. Examination of single-stage and full-scale engine compressor noise measurements leads to a prediction technique being evolved for inlet and efflux levels.


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