Investigation of the effect of pilot burner on lean blow out performance of a staged injector

2014 ◽  
Vol 23 (6) ◽  
pp. 600-608 ◽  
Author(s):  
Jinhu Yang ◽  
Kaiyu Zhang ◽  
Cunxi Liu ◽  
Changlong Ruan ◽  
Fuqiang Liu ◽  
...  
Keyword(s):  
Author(s):  
L. Rosentsvit ◽  
Y. Levy ◽  
V. Erenburg ◽  
V. Sherbaum ◽  
V. Ovcharenko ◽  
...  

The present work is concerned with improving combustion stability in lean premixed (LP) gas turbine combustors by injecting free radicals into the combustion zone. The work is a joint experimental and numerical effort aimed at investigating the feasibility of incorporating a circumferential pilot combustor, which operates under rich conditions and directs its radicals enriched exhaust gases into the main combustion zone as the means for stabilization. The investigation includes the development of a chemical reactors network (CRN) model that is based on perfectly stirred reactors modules and on preliminary CFD analysis as well as on testing the method on an experimental model under laboratory conditions. The study is based on the hypothesis that under lean combustion conditions, combustion instability is linked to local extinctions of the flame and consequently, there is a direct correlation between the limiting conditions affecting combustion instability and the lean blowout (LBO) limit of the flame. The experimental results demonstrated the potential reduction of the combustion chamber's LBO limit while maintaining overall NOx emission concentration values within the typical range of low NOx burners and its delicate dependence on the equivalence ratio of the ring pilot flame. A similar result was revealed through the developed CHEMKIN-PRO CRN model that was applied to find the LBO limits of the combined pilot burner and main combustor system, while monitoring the associated emissions. Hence, both the CRN model, and the experimental results, indicate that the radicals enriched ring jet is effective at stabilizing the LP flame, while keeping the NOx emission level within the characteristic range of low NOx combustors.


2013 ◽  
Vol 724-725 ◽  
pp. 1625-1629
Author(s):  
Peter Rantuch ◽  
Tomáš Chrebet ◽  
Karol Balog

This paper deals with expanded polystyrene (EPS) as a potential source of smoke. We compared specific optical density of smoke from EPS and EPS strengthened by glass fibre mash and plaster which is used in external thermal insulation composite systems (ETICS). There was used testing method by ISO 5659 Plastics Smoke generation Part 2: Determination of optical density by a single-chamber test. The samples were exposed to a constant 50 kW.m-2 of thermal radiation. There was not used a pilot burner. During flame combustion samples evolved high amount of smoke. Samples from EPS released more smoke like samples with ETICS cover.


Author(s):  
G. Riccio ◽  
S. Piazzini ◽  
P. Adami ◽  
F. Martelli ◽  
G. Tanzini ◽  
...  

Different geometrical modifications have been investigated and experimentally tested to improve a pilot burner for low emission industrial gas turbine combustors. Results of the ongoing collaboration between the DE of Florence and the Italian electric company ENEL are reported. The activity is dedicated to the improvement of the pilot burner to extend the operable margin of the engine and to reduce, at the same time, the emissions. The study has been performed mainly by means of experimental investigations both on isothermal flow as on combustion test rig. Results of the activity were employed both to obtain design information about the swirler and injection fuel holes for the pilot burner under investigation. Moreover the post-processing of the experimental data permitted the improvement of the correlation implemented into the 1-D model for the prediction of the injected fuel path. These results were implemented in the routine DoFHIS (Design of Fuel Holes Injection Systems) developed for the analysis/design of injection fuel systems.


Author(s):  
Hasan Karim ◽  
Kent Lyle ◽  
Shahrokh Etemad ◽  
Lance Smith ◽  
William Pfefferle ◽  
...  

This paper describes the design and testing of a catalytically-stabilized pilot burner for current and advanced Dry Low NOx (DLN) gas turbine combustors. In this paper, application of the catalytic pilot technology to industrial engines is described using Solar Turbines’ Taurus 70 engine. The objective of the work described is to develop the catalytic pilot technology and document the emission benefits of catalytic pilot technology when compared to higher, NOx producing pilots. The catalytic pilot was designed to replace the existing pilot in the existing DLN injector without major modification to the injector. During high pressure testing, the catalytic pilot showed no incidence of flashback or autoignition while operating over wide range of combustion temperatures. The catalytic reactor lit off at a temperature of approximately 598K (325°C/617°F) and operated at simulated 100% and 50% load conditions without a preburner. At high pressure, the maximum catalyst surface temperature was similar to that observed during atmospheric pressure testing and considerably lower than the surface temperature expected in lean-burn catalytic devices. In single injector rig testing, the integrated assembly of the catalytic pilot and Taurus 70 injector demonstrated NOx and CO emission less than 5 ppm @ 15% O2 for 100% and 50% load conditions along with low acoustics. The results demonstrate that a catalytic pilot burner replacing a diffusion flame or partially-premixed pilot in an otherwise DLN combustor can enable operation at conditions with substantially reduced NOx emissions.


Author(s):  
Marzena Półka ◽  
Anna Szajewska

The paper presents results of tests related to smoke optical density conducted on four various textile floor coverings for the needs of building interior design. Smoke emission is one of basic elements that characterize the fire environment. Consequently, the objective of the paper was to carry out a comparative analysis of smoke generation of chosen floor coverings for selected thermal exposures and in the presence or absence of a stimulus igniting the volatile gaseous phase (pilot flame). For the needs of our experimental research use was made of polypropylene, polyester, composite of wool, cotton, viscose and polyamide floor coverings. The highest value of the maximum specific optical density of smoke (494.7) was recorded for the floor covering consisting of 100% polypropylene (with higher fiber) under flameless combustion conditions (without the pilot flame). The polypropylene floor covering without underlay proved to be the best material from among all the tested ones with respect to smoke generating properties, and its samples offered the lowest value of optical density after 4 min for testing variants without the application of a pilot burner, with the flammable phase of decomposition products of this sample during the testing in which the burner was used to ignite at the latest. Experimental research has been carried out based on the standard ISO 5659–2:2017–08. The tests results were compared with international optical smoke density requirements for the interior design of ships and trains.


2003 ◽  
Vol 125 (4) ◽  
pp. 879-884 ◽  
Author(s):  
H. Karim ◽  
K. Lyle ◽  
S. Etemad ◽  
L. L. Smith ◽  
W. C. Pfefferle ◽  
...  

This paper describes the design and testing of a catalytically stabilized pilot burner for current and advanced Dry Low NOx (DLN) gas turbine combustors. In this paper, application of the catalytic pilot technology to industrial engines is described using Solar Turbines’ Taurus 70 engine. The objective of the work described is to develop the catalytic pilot technology and document the emission benefits of catalytic pilot technology when compared to higher, NOx producing pilots. The catalytic pilot was designed to replace the existing pilot in the existing DLN injector without major modification to the injector. During high-pressure testing, the catalytic pilot showed no incidence of flashback or autoignition while operating over wide range of combustion temperatures. The catalytic reactor lit off at a temperature of approximately 598 K (325°C/617°F) and operated at simulated 100% and 50% load conditions without a preburner. At high pressure, the maximum catalyst surface temperature was similar to that observed during atmospheric pressure testing and considerably lower than the surface temperature expected in lean-burn catalytic devices. In single-injector rig testing, the integrated assembly of the catalytic pilot and Taurus 70 injector demonstrated NOx and CO emission less than 5 ppm @ 15% O2 for 100% and 50% load conditions along with low acoustics. The results demonstrate that a catalytic pilot burner replacing a diffusion flame or partially premixed pilot in an otherwise DLN combustor can enable operation at conditions with substantially reduced NOx emissions.


Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1115
Author(s):  
Cheol Woo Lee ◽  
In Su Kim ◽  
Jung Goo Hong

Various kinds of pilot burners were experimentally investigated to examine the effects of their geometry and their location relative to the main burner of a real size combustor. In addition, a wide range of fuel equivalence ratios were investigated to analyze the feasibility of the novel pilot burner for the conventional burner application. From the results, it is shown that the novel pilot burner with multi air holes had a thin, straight, long and stable pilot flame, while the conventional pilot burner had a thick, lifted, short and unstable flame. It is also shown that the novel pilot burner with an upper air flow hole had a straight pilot flame which led to less thermal damage to the burner combustor. This study suggests that not only pilot burner flame shape but also the vertical location of the pilot burner from the main burner combustor has a significant effect on combustor durability.


Author(s):  
H. Yamada ◽  
K. Shimodaira ◽  
S. Hayashi

The design and on–engine testing of a lean–premixed, low–NOx combustor for a simple cycle, single shaft, 250–kW gas turbine engine of a pressure ratio of eight are described. A variable geometry system composed of butterfly air valves was used to control the combustor air split between combustion and dilution. Fuel was staged to a direct–injection pilot burner and a lean–premixed main burner fitted to the combustor liner. The NOx emissions with natural gas fueling were found to be less than 20 ppm (at 15% O2) at and near full load conditions with combustion efficiencies greater than 99.8%. Emissions data from early high–pressure rig tests of the combustor hardware are also presented.


Sign in / Sign up

Export Citation Format

Share Document