A Diffusion Limited Model That Accurately Predicts the NOx Emissions From Gas Turbine Combustors Including the Use of Nitrogen Containing Fuels

1976 ◽  
Vol 98 (3) ◽  
pp. 320-326 ◽  
Author(s):  
W. S. Y. Hung
Keyword(s):  
Gas Turbine ◽  
Water Injection ◽  
Combustion Process ◽  
Nox Emissions ◽  
Nox Formation ◽  
Gas Turbine Combustors ◽  
Injection Process ◽  
Hydrocarbon Combustion ◽  
Diffusion Limited ◽  
Thermal Nox

A diffusion limited model has been described previously to simulate accurately the thermal NOx emission processes in various gas turbine combustors for fuels containing negligible amounts of fuel bound nitrogen. The application of this model to simulate accurately the water injection process has also been demonstrated. It is currently proposed that any bound nitrogen in fuel is completely reacted to form nitric oxide during the hydrocarbon combustion process; the ultimate net conversion is determined subsequently based on the Zeldovich mechanisms. With this additional assumption, this model has been generalized to include the use of fuels containing significant amounts of bound nitrogen, such as crude or residual oils. The predicted NOx emissions from these nitrogen containing fuels are in excellent agreement with laboratory and field data including the effect of water injection. Comprehensive understanding of the NOx formation processes has been gained from the current analytical study.

scholarly journals An Experimentally Verified NOx Emission Model for Gas Turbine Combustors

1975 ◽  
Author(s):  
W. S. Y. Hung
Keyword(s):  
Gas Turbine ◽  
Analytical Model ◽  
Field Data ◽  
Experimental Testing ◽  
A Priori ◽  
Water Injection ◽  
Nox Emission ◽  
Nox Emissions ◽  
Emission Model ◽  
Gas Turbine Combustors

An analytical model has been developed to simulate the thermal NOx emission processes in various gas turbine combustors for a variety of fuels. The NOx emissions predicted by the model are in excellent agreement with available laboratory and field data. Its capability to simulate the water injection process accurately has been demonstrated previously. Comprehensive understanding of the NOx emission processes in gas turbine combustors has been gained through the current analytical studies. NOx emissions as influenced by ambient humidity, changes in combustor geometry, type of fuel used and changes in operating parameters can now be evaluated quantitatively through a priori prediction and have been verified by available laboratory and field data. The analytical model has also been demonstrated to be a powerful guidance tool in directing the experimental testing program in an effort to reduce NOx emissions from gas turbine combustors.

scholarly journals A NOx Correlation Method for Gas Turbine Combustors Based on NOx Formation Assumptions

1974 ◽  
Author(s):  
Géza Vermes
Keyword(s):  
Gas Turbine ◽  
A Priori ◽  
Combustion Process ◽  
Correlation Method ◽  
Inlet Temperature ◽  
Nox Emissions ◽  
Gas Turbine Combustor ◽  
Nox Formation ◽  
Simple Method ◽  
Fuel Flow

Based on a simplified description of the combustion process in the primary zone of a can type gas turbine combustor, a generalized NOx versus fuel flow relationship is proposed. Using this relationship and considerations based on chemical kinetics, the effect of combustor inlet pressure, inlet temperature and air residence time on NOx formation is investigated in industrial and automotive type combustion chambers. Data reported in the literature and original test work is cited to substantiate the validity of the assumptions. Based on the findings, a simple method is presented to predict NOx emissions of a gas turbine combustor under conditions which differ substantially from those of the test run. The assumptions may be used to assemble a model for a priori prediction of NOx emissions in a given combustion geometry.

Field Conversion of a Low-Firing Frame 7B Gas Turbine Power Plant to Ultra-Low Emission Combustion

2015 ◽  
Author(s):  
Nicolas Demougeot ◽  
Jeffrey A. Benoit
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Energy Demand ◽  
Water Injection ◽  
Cost Benefit ◽  
High Energy ◽  
Nox Emissions ◽  
Environmental Controls ◽  
Low Emission ◽  
Technical Discussion

The search for power plant sustainability options continues as regulating agencies exert more stringent industrial gas turbine emission requirements on operators. Purchasing power for resale, de-commissioning current capabilities altogether and repowering by replacing or converting existing equipment to comply with emissions standards are economic-driven options contemplated by many mature gas turbine operators. NRG’s Gilbert power plant based in Milford, NJ began commercial operation in 1974 and is fitted with four (4) natural gas fired GE’s 7B gas turbine generators with two each exhausting to HRSG’s feeding one (1) steam turbine generator. The gas turbine units, originally configured with diffusion flame combustion systems with water injection, were each emitting 35 ppm NOx with the New Jersey High Energy Demand Day (HEED) regulatory mandate to reduce NOx emissions to sub 10 ppm by May 1st, 2015. Studies were conducted by the operator to evaluate the economic viability & installation of environmental controls to reduce NOx emissions. It was determined that installation of post-combustion environmental controls at the facility was both cost prohibitive and technically challenging, and would require a fundamental reconfiguration of the facility. Based on this economic analysis, the ultra-low emission combustion system conversion package was selected as the best cost-benefit solution. This technical paper will focus on the ultra low emissions technology and key features employed to achieve these low emissions, a description of the design challenges and solution to those, a summary of the customer considerations in down selecting options and an overview of the conversion scope. Finally, a technical discussion of the low emissions operational flexibility will be provided including performance results of the converted units.

A Critical Review of NOx Correlations for Gas Turbine Combustors

1975 ◽  
Author(s):  
D. A. Sullivan ◽  
P. A. Mas
Keyword(s):  
Experimental Data ◽  
Data Base ◽  
Gas Turbine ◽  
Critical Review ◽  
Inlet Temperature ◽  
Nox Emissions ◽  
Empirical Correlations ◽  
Gas Turbine Combustors ◽  
Semi Empirical ◽  
Adequate Data

The effect of inlet temperature, pressure, air flowrate and fuel-to-air ratio on NOx emissions from gas turbine combustors has received considerable attention in recent years. A number of semi-empirical and empirical correlations relating these variables to NOx emissions have appeared in the literature. They differ both in fundamental assumptions and in their predictions. In the present work, these simple NOx correlations are compared to each other and to experimental data. A review of existing experimental data shows that an adequate data base does not exist to evaluate properly the various NOx correlations. Recommendations are proposed to resolve this problem in the future.

scholarly journals A Reheat Gas Turbine Oilfield Cogeneration System, Fueled With Heavy Crude Oil, Which Produces Very Low NOx Emissions

1987 ◽  
Author(s):  
Frederick E. Moreno ◽  
Philip J. Divirgilio
Keyword(s):  
Crude Oil ◽  
Gas Turbine ◽  
Steam Generator ◽  
Oil Recovery ◽  
Catalytic Reduction ◽  
Water Injection ◽  
Industrial Process ◽  
Field Testing ◽  
Nox Emissions ◽  
Cogeneration System

A gas turbine cogeneration system is described that offers fuel flexibility plus substantially reduced NOx emissions without water injection or selective catalytic reduction (SCR). The entirely new turbine design developed by TurboEnergy Systems permits boiler repowering and other cogeneration applications. The first application will be in the California heavy oilfields; the system will be retrofitted to an existing 50 million btu/hr oilfield steam generator used in thermally enhanced oil recovery. The turbine, rated at 1250 kw (site output), was sized to match the combustion air flow requirements of the steam generator. A reheated design was selected to maximize power output from the limited airflow available and to maximize the exhaust temperature for cogeneration and industrial process applications. The oilfield cogeneration system being developed includes a new heavy oil burner for the steam generator which will be fired on the high temperature exhaust from the turbine. The system will also provide low NOx emissions, below the tightest projected standards in Kern County, which has a large concentration of heavy oilfields. Both the turbine and the steam generator burner will burn heavy (API 13 gravity) crude oil. The paper describes the overall system, its interface with the existing process, the design techniques used, and presents performance projections. Field testing will begin at a site near Bakersfield, California, starting in early to mid-1987.

The Effect of Water Injection for Emissions Control on Industrial Gas Turbine Combustors

1984 ◽  
Author(s):  
R. J. Antos ◽  
W. C. Emmerling
Keyword(s):  
Gas Turbines ◽  
Mechanical Design ◽  
Water Injection ◽  
Combustion Process ◽  
Liquid Fuels ◽  
Nox Emissions ◽  
Design Features ◽  
Industrial Gas Turbines ◽  
Comprehensive Test ◽  
Industrial Gas Turbine

One common method of reducing the NOx emissions from industrial gas turbines is to inject water into the combustion process. The amount of water injected depends on the emissions rules that apply to a particular unit. Westinghouse W501B industrial gas turbines have been operated at water injection levels required to meet EPA NOx emissions regulations. They also have been operated at higher injection levels required to meet stricter California regulations. Operation at the lower rates of water did not affect combustor inspection and/or repair intervals. Operation on liquid fuels with high rates of water also did not result in premature distress. However, operation on gas fuel at high rates of water did cause premature distress in the combustors. To evaluate this phenomenon, a comprehensive test program was conducted; it demonstrated that the distress is the result of the temperature patterns in the combustor caused by the high rates of water. The test also indicated that there is no significant change in dynamic response levels in the combustor. This paper presents the test results, and the design features selected to substantially improve combustor wall temperature when operating on gas fuels, with the high rates of water injection required to meet California applications. Mechanical design features that improve combustor resistance to water injection-induced thermal gradients also are presented.

Closed-Loop Combustion Control Using OH Radical Emissions

2000 ◽  
Author(s):  
Zhu (Julie) Meng ◽  
Robert J. Hoffa ◽  
Charles A. DeMilo ◽  
Todd T. Thamer
Keyword(s):  
Control System ◽  
Simulation Model ◽  
Gas Turbine ◽  
Closed Loop ◽  
System Simulation ◽  
Combustion Process ◽  
Operating Conditions ◽  
Nox Emissions ◽  
Oh Radical ◽  
Emissions Control

The combustion process in gas-turbine engines produces emissions, especially nitrogen oxides (NOx) and carbon monoxide (CO), which change dramatically with combustor operating conditions. As part of this study, the application of active feedback control technologies to reduce thermal NOx emissions is modeled numerically and demonstrated experimentally. A new optical flame sensor, designed by Ametek Power & Industrial Products, has been successfully implemented as the feedback element in a proof-of-concept control system used to minimize NOx emissions. The sensor consists of a robust mechanical package, as well as electronics suitable for severe gas-turbine environments. Results from system rig tests correlate closely to theoretical predictions, as described in literature and produced by a control system simulation model. The control system simulation model predicts the efficacy of controlling engine operating characteristics based on chemical luminescence of the OH radical. The model consists of a fuel pump and metering device, a fuel-air mixing scheme, a combustion model, the new ultraviolet (UV) feedback flame sensor, and a simple gain block. The input reference to the proportional emissions control is the fuel-to-air equivalence ratio, which is empirically correlated to the desired low level of NOx emissions while satisfying other operating conditions, such as CO emissions and power. Results from the closed-loop emissions control simulation and rig tests were analyzed to determine the capability of the UV flame sensor to measure and control the combustion process in a gas-turbine engine. The response characteristics, overshoot percentage, rise time, settling time, accuracy, resolution, and repeatability are addressed.

User Experience: Operating a 300 MW Base Load Cogeneration Plant With High Water Injection Rates to Control NOx Emissions

1989 ◽  
Author(s):  
William E. Hauhe ◽  
Gary L. Haub ◽  
Charles O. Myers ◽  
Donald C. Guthan ◽  
David O. Fitts
Keyword(s):  
Gas Turbine ◽  
User Experience ◽  
Water Injection ◽  
High Water ◽  
Operational Reliability ◽  
Oil Field ◽  
Nox Emissions ◽  
Cogeneration Plant ◽  
Base Load ◽  
Reliability And Availability

This paper describes user experience with the operation and maintenance of a gas turbine based cogeneration plant operating at base load while injecting up to 80 gpm (303 l/min) of water to control NOx emissions to 42 ppmv (at 15% O2). The plant, located in the Kern River Oil Field, near Bakersfield, California, has produced an average of 294.6 MWe and 1.903 million lbs/hr (0.863 million kg/hr) of steam since achieving commercial operation in August, 1985. To date, the plant has achieved an operational reliability and availability of 98.9% and 95.4%, respectively. The effects of water injection on combustion hardware, as well as, overall gas turbine reliability and availability and equipment enhancements will be discussed.

New Catalytic Combustion Technology for Very Low Emissions Gas Turbines

1994 ◽  
Author(s):  
R. A. Dalla Betta ◽  
J. C. Schlatter ◽  
S. G. Nickolas ◽  
D. K. Yee ◽  
T. Shoji
Keyword(s):  
Thermal Shock ◽  
Gas Turbine ◽  
High Temperatures ◽  
Gas Turbines ◽  
Catalytic Combustion ◽  
Combustion Process ◽  
Combustion System ◽  
Gas Turbine Combustors ◽  
Homogeneous Combustion ◽  
Combustion Technology

A catalytic combustion system has been developed which feeds full fuel and air to the catalyst but avoids exposure of the catalyst to the high temperatures responsible for deactivation and thermal shock fracture of the supporting substrate. The combustion process is initiated by the catalyst and is completed by homogeneous combustion in the post catalyst region where the highest temperatures are obtained. This has been demonstrated in subscale test rigs at pressures up to 14 atmospheres and temperatures above 1300°C (2370°F). At pressures and gas linear velocities typical of gas turbine combustors, the measured emissions from the catalytic combustion system are NOx < 1 ppm, CO < 2 ppm and UHC < 2 ppm, demonstrating the capability to achieve ultra low NOx and at the same time low CO and UHC.

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