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.

Sootblowing Optimization Improves Heat Rate and Enhances Operational Flexibility at Hawthorn Unit 5

2014 ◽  
Author(s):  
Neel J. Parikh ◽  
Peter Rogge ◽  
Kenneth Luebbert
Keyword(s):  
Control System ◽  
Closed Loop ◽  
Heat Rate ◽  
Operating Conditions ◽  
Operational Experience ◽  
Unit Operation ◽  
Gas Temperature ◽  
Dynamic Adjustment ◽  
Operational Parameters ◽  
Unit Load

Coal-fired units are increasingly expected to operate at varying loads while simultaneously dealing with various operational influences as well as fuel variations. Maintaining unit load availability while managing adverse effects of various operational issues such as, flue gas temperature excursions at the SCR inlet, high steam temperatures and the like presents significant challenges. Dynamic adjustment of sootblowing activities and different operational parameters is required to effectively control slagging, fouling and achieve reliability in unit operation. Closed-loop optimizers aim to reduce ongoing manual adjustments by control operators and provide consistency in unit operation. Such optimizers are typically computer software-based and work by interfacing an algorithmic and/or artificial intelligence based decision making system to plant control system [1]. KCP&L is in the process of implementing Siemens SPPA-P3000 combustion and sootblowing optimizers at several Units. The Sootblowing Optimizer solution determines the need for sootblowing based on dynamic plant operating conditions, equipment availability and plant operational drivers. The system then generates sootblower activation signals for propagation in a closed-loop manner to the existing sootblower control system at ‘optimal’ times. SPPA-P3000 Sootblowing Optimizer has been successfully installed at Hawthorn Unit 5, a 594-MW, wall-fired boiler, firing 100 percent Powder River Basin coal. This paper discusses implementation approach as well as operational experience with the Sootblowing Optimizer and presents longer-term operational trends showing unit load sustainability and heat rate improvement.

Combustion Characteristics of Small Size Gas Turbine Combustor Fueled by Biomass Gas Employing Flameless Combustion

2007 ◽  
Author(s):  
Masato Hiramatsu ◽  
Yoshifumi Nakashima ◽  
Sadamasa Adachi ◽  
Yudai Yamasaki ◽  
Shigehiko Kaneko
Keyword(s):  
Gas Turbine ◽  
Combustion Efficiency ◽  
Combustion Characteristics ◽  
Operating Conditions ◽  
Nox Emissions ◽  
Gas Turbine Combustor ◽  
Flameless Combustion ◽  
Engine Exhaust ◽  
Micro Gas Turbine

One approach to achieving 99% combustion efficiency (C.E.) and 10 ppmV or lower NOx (at 15%O2) in a micro gas turbine (MGT) combustor fueled by biomass gas at a variety of operating conditions is with the use of flameless combustion (FLC). This paper compares experimentally obtained results and CHEMKIN analysis conducted for the developed combustor. As a result, increase the number of stage of FLC combustion enlarges the MGT operation range with low-NOx emissions and high-C.E. The composition of fuel has a small effect on the characteristics of ignition in FLC. In addition, NOx in the engine exhaust is reduced by higher levels of CO2 in the fuel.

Experimental Assessment of the Emissions Benefits of a Ceramic Gas Turbine Combustor

1996 ◽  
Author(s):  
K. O. Smith ◽  
A. Fahme
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Flow Distribution ◽  
Operating Conditions ◽  
Nox Emissions ◽  
Fuel Injector ◽  
Gas Turbine Combustor ◽  
Experimental Assessment ◽  
Industrial Gas Turbine ◽  
Combustor Liner

Three subscale, cylindrical combustors were rig tested on natural gas at typical industrial gas turbine operating conditions. The intent of the testing was to determine the effect of combustor liner cooling on NOx and CO emissions. In order of decreasing liner cooling, a metal louvre-cooled combustor, a metal effusion-cooled combustor, and a backside-cooled ceramic (CFCC) combustor were evaluated. The three combustors were tested using the same lean-premixed fuel injector. Testing showed that reduced liner cooling produced lower CO emissions as reaction quenching near the liner wall was reduced. A reduction in CO emissions allows a reoptimization of the combustor air flow distribution to yield lower NOx emissions.

Numerical and Experimental Evaluation of a Dual-Fuel Dry-Low-NOx Micromix Combustor for Industrial Gas Turbine Applications

2018 ◽  
Vol 11 (1) ◽  
Author(s):  
Harald H. W. Funke ◽  
Nils Beckmann ◽  
Jan Keinz ◽  
Sylvester Abanteriba
Keyword(s):  
Gas Turbine ◽  
Combustion Process ◽  
Experimental Studies ◽  
Research Process ◽  
Operating Conditions ◽  
Experimental Investigations ◽  
Dual Fuel ◽  
Pure Hydrogen ◽  
Ongoing Research ◽  
Industrial Gas Turbine

Abstract The dry-low-NOx (DLN) micromix combustion technology has been developed originally as a low emission alternative for industrial gas turbine combustors fueled with hydrogen. Currently, the ongoing research process targets flexible fuel operation with hydrogen and syngas fuel. The nonpremixed combustion process features jet-in-crossflow-mixing of fuel and oxidizer and combustion through multiple miniaturized flames. The miniaturization of the flames leads to a significant reduction of NOx emissions due to the very short residence time of reactants in the flame. The paper presents the results of a numerical and experimental combustor test campaign. It is conducted as part of an integration study for a dual-fuel (H2 and H2/CO 90/10 vol %) micromix (MMX) combustion chamber prototype for application under full scale, pressurized gas turbine conditions in the auxiliary power unit Honeywell Garrett GTCP 36-300. In the presented experimental studies, the integration-optimized dual-fuel MMX combustor geometry is tested at atmospheric pressure over a range of gas turbine operating conditions with hydrogen and syngas fuel. The experimental investigations are supported by numerical combustion and flow simulations. For validation, the results of experimental exhaust gas analyses are applied. Despite the significantly differing fuel characteristics between pure hydrogen and hydrogen-rich syngas, the evaluated dual-fuel MMX prototype shows a significant low NOx performance and high combustion efficiency. The combustor features an increased energy density that benefits manufacturing complexity and costs.

scholarly journals Development and installation of control system for a test rig interconnecting a micro Gas Turbine, a Heat Pump and a PCM Storage system

2019 ◽  
Vol 113 ◽  
pp. 01003
Author(s):  
Iacopo Rossi ◽  
Romain Caillere
Keyword(s):  
Control System ◽  
Gas Turbine ◽  
Heat Pump ◽  
Storage System ◽  
Electrical Energy ◽  
Operating Conditions ◽  
Lower Amount ◽  
Test Bed ◽  
Micro Gas Turbine ◽  
Electrical Energy Production

The need to enhance flexibility on current power plant is linked to the strong penetration of non-dispatchable sources in the current energy network, which causes a dramatic need for ancillary services to sustain the grid operability. A framework including a micro Gas Turbine (mGT), a Heat Pump (HP) and a PCM Storage is considered to enhance plant flexibility while facing grid and price fluctuations during day operations. The system so composed is devoted to electrical energy production only. A proper use of the HP allows, for instance, to heat up the compressor intake temperature whilst the system is operating at minimum load. The system can then produce a lower amount of energy in order to be more competitive in the infra-day energy market. At the same time, the cold storage is charged and the stored energy can be later used to power up the system during the peak hours by cooling the compressor intake. This work presents then the installation of the control system devoted to the management and the control of such complex system. The test-bed is defined to test different operating conditions and to validate the operating framework of the whole compound.

Numerical Investigations of NOx Emissions of a Partially Premixed Burner for Natural Gas Operations in Industrial Gas Turbine

2014 ◽  
Author(s):  
Alessandro Innocenti ◽  
Antonio Andreini ◽  
Andrea Giusti ◽  
Bruno Facchini ◽  
Matteo Cerutti ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Turbulent Combustion ◽  
Fuel Injection ◽  
Formation Rate ◽  
Operating Conditions ◽  
Combustion Model ◽  
Nox Emissions ◽  
Air Concentration ◽  
Partially Premixed ◽  
Industrial Gas Turbine

In the present paper a numerical analysis of a low NOx partially premixed burner for industrial gas turbine applications is presented. The first part of the work is focused on the study of the premixing process inside the burner. Standard RANS CFD approach was used: k–ε turbulence model was modified and calibrated in order to find a configuration able to fit available experimental profiles of fuel/air concentration at the exit of the burner. The resulting profiles at different test points have been used to perform reactive simulations of an experimental test rig, where exhaust NOx emissions were measured. An assessment of the turbulent combustion model was carried out with a critical investigation of the expected turbulent combustion regimes in the system and taking into account the partially premixed nature of the flame due to the presence of diffusion type pilot flames. A reliable numerical setup was discovered by comparing predicted and measured NOx emissions at different operating conditions and at different split ratio between main and pilot fuel. In the investigated range, the influence of the premixer in the NOx formation rate was found to be marginal if compared with the pilot flame one. The calibrated numerical setup was then employed to explore possible modifications to fuel injection criteria and fuel split, with the aim of minimizing exhaust NOx emissions. This preliminary numerical screening of alternative fuel injection strategies allowed to define a set of advanced configurations to be investigated in future experimental tests.

Measurement of Smoke Particle Size and Distribution Within a Gas Turbine Combustor

2005 ◽  
Vol 127 (2) ◽  
pp. 286-294 ◽  
Author(s):  
K. D. Brundish ◽  
M. N. Miller ◽  
C. W. Wilson ◽  
M. Jefferies ◽  
M. Hilton ◽  
...  
Keyword(s):  
Particle Size ◽  
Gas Turbine ◽  
Fluid Dynamic ◽  
Combustion Process ◽  
Analytical Techniques ◽  
Number Concentration ◽  
Operating Conditions ◽  
Fuel Injector ◽  
Gas Turbine Combustor ◽  
Smoke Particle

The objective of the work described in this paper was to identify a method of making measurements of the smoke particle size distribution within the sector of a gas turbine combustor, using a scanning mobility particle sizing (SMPS) analyzer. As well as gaining a better understanding of the combustion process, the principal reasons for gathering these data was so that they could be used as validation for computational fluid dynamic and chemical kinetic models. Smoke mass and gaseous emission measurements were also made simultaneously. A “water cooled,” gas sampling probe was utilized to perform the measurements at realistic operating conditions within a generic gas turbine combustor sector. Such measurements had not been previously performed and consequently initial work was undertaken to gain confidence in the experimental configuration. During this investigation, a limited amount of data were acquired from three axial planes within the combustor. The total number of test points measured were 45. Plots of the data are presented in two-dimensional contour format at specific axial locations in addition to axial plots to show trends from the primary zone to the exit of the combustor. Contour plots of smoke particle size show that regions of high smoke number concentration once formed in zones close to the fuel injector persist in a similar spatial location further downstream. Axial trends indicate that the average smoke particle size and number concentration diminishes as a function of distance from the fuel injector. From a technical perspective, the analytical techniques used proved to be robust. As expected, making measurements close to the fuel injector proved to be difficult. This was because the quantity of smoke in the region was greater than 1000mg/m3. It was found necessary to dilute the sample prior to the determination of the particle number concentration using SMPS. The issues associated with SMPS dilution are discussed.

Flashback Propensity of Syngas Flames at High Pressure: Diagnostic and Control

2010 ◽  
Author(s):  
S. Daniele ◽  
P. Jansohn ◽  
K. Boulouchos
Keyword(s):  
Control System ◽  
Gas Turbine ◽  
Turbulent Flame ◽  
Back Propagation ◽  
Combined Cycle ◽  
Operating Conditions ◽  
Inlet Temperature ◽  
Experimental Facility ◽  
Inlet Velocity ◽  
Turbulent Flame Speed

Nowadays, the establishment of IGCC (integrated gasification combined cycle) plants, prompts a growing interest in synthetic fuels for gas turbine based power generation. This interest has as direct consequence the need for understanding of flashback phenomena for premixed systems operated with H2-rich gases. This is due to the different properties of H2 (e.g. reactivity and diffusivity) with respect to CH4 which lead to higher flame speeds in the case of syngases (mixtures of H2-CO). This paper presents the results of experiments at gas turbine like conditions (pressure up to 15 bar, 0.2 < Φ < 0.7, 577K < T0 < 674K) aimed to determine flashback limits and their dependence on the combustion parameters (pressure, inlet temperature and inlet velocity). For the experimental facility used for this work the back propagation of the flame is believed to happen into the boundary layer of the fuel/air duct. Flashback propensity was found to have an appreciable dependence on pressure and inlet temperature while the effects of inlet velocity variations are weak. Explanations for the dependence on these three parameters, based on consideration on laminar and turbulent flame speed data (from modeling and experiments), are proposed. Within the frame of this work, in order to avoid major damages, the experimental facility was equipped with an automatic control system for flashback described in the paper. The control system is able to detect flame propagation into the fuel/air supply, arrest it and restore safe operating conditions by moving the flame out of the fuel/air section without blowing it out. This avoids destruction of components (burner/mixing) and time consuming shut downs of the test rig.

Effects of Inlet Flow Distortion on the Performance of Aircraft Gas Turbines

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Joachim Kurzke
Keyword(s):  
Control System ◽  
Gas Turbines ◽  
System Simulation ◽  
Engine Performance ◽  
Thermodynamic Cycle ◽  
Operating Conditions ◽  
Flow Distortion ◽  
Inlet Flow ◽  
Inlet Flow Distortion ◽  
The Impact

This paper describes how the fundamental effects of inlet flow distortion on the performance of gas turbines can be evaluated with any engine performance program that employs an integrated parallel compressor model. In this simulation method, both pressure and temperature distortions are quantified with coefficients, which relate the pressure (respectively temperature) in the spoiled sector to the value in the clean sector. In single spool compressor engines, the static pressure at the exit of the clean sector equals that of the distorted sector. This hypothesis does not hold true with multispool compressor engines because the short intercompressor ducts, which often contain struts or vanes, do not allow the mass flow transfer over the sector borders, which would be required for balancing the static pressures. The degree of aerodynamic coupling of compressors in series can be described in the performance simulation program by the simple coupling factor introduced in this paper. There are two fundamentally different reasons for the change in engine performance: First, there is the impact of the flow distortion on the component efficiencies and thus the thermodynamic cycle and second there are performance changes due to the actions of the control system. From the engine system simulation results, it becomes clear why inlet flow distortion has only a minor impact on the thermodynamic cycle if the comparison of the two operating conditions (with clean and distorted inlet flow) is made at the properly averaged engine inlet conditions. For each compressor, the parallel compressor theory yields two operating points in the map, one for the clean sector and one for the spoiled sector. The performance loss due to the distortion is small since the efficiency values in the two sectors are only a bit lower than the efficiency at a comparable operating point with clean inlet flow. However, the control system of the engine can react to the inlet flow distortion in such a way that the thrust delivered changes significantly. This is particularly true if a compressor bleed valve or a variable area nozzle is opened to counteract compressor stability problems. Especially, using recirculating bleed air for increasing the surge margin of a compressor affects the performance of the engine negatively. Two examples show clearly that the pros and cons of recirculating bleed can only be judged with a full system simulation; looking at the surge line improvement alone can be misleading.

Development of a Liquid-Fueled, Lean-Premixed Gas Turbine Combustor

1993 ◽  
Vol 115 (3) ◽  
pp. 554-562 ◽  
Author(s):  
L. H. Cowell ◽  
K. O. Smith
Keyword(s):  
Gas Turbine ◽  
Performance Testing ◽  
Operating Conditions ◽  
Operating Parameters ◽  
Nox Emissions ◽  
Fuel Injector ◽  
Design Variables ◽  
Lean Premixed ◽  
Annular Combustor ◽  
Injector Design

Development of a lean-premixed, liquid-fueled combustor is in progress to achieve ultra-low NOx emissions at typical gas turbine operating conditions. A filming fuel injector design was tested on a bench scale can combustor to evaluate critical design and operating parameters for low-emissions performance. Testing was completed using No. 2 diesel. Key design variables tested include premixing length, swirler angle, injector centerbody diameter, and reduced liner cooling. NOx emissions below 12 ppmv at 9 bar pressure were measured. Corresponding CO levels were 50 ppmv. An optimized injector design was fabricated for testing in a three injector sector of an annular combustor. Operating parameters and test results are discussed in the paper.

Sign in / Sign up

Export Citation Format

Share Document