Experimental Investigation of Filtration Combustion Instability with Lean Premixed Hydrogen/Air in a Packed Bed

2012 ◽  
Vol 26 (8) ◽  
pp. 4749-4755 ◽  
Author(s):  
Yongfang Xia ◽  
Junrui Shi ◽  
Benwen Li ◽  
Chunmei Yu ◽  
Youning Xu ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Filtration Combustion ◽  
Combustion Instability ◽  
Packed Bed ◽  
Lean Premixed

Characteristic analysis of low-velocity gas filtration combustion in an inert packed bed

2006 ◽  
Vol 10 (4) ◽  
pp. 683-700 ◽  
Author(s):  
G. Zhang ◽  
X. Cai ◽  
M. Liu ◽  
B. Lin ◽  
Y. Chen ◽  
...  
Keyword(s):  
Filtration Combustion ◽  
Packed Bed ◽  
Gas Filtration ◽  
Characteristic Analysis ◽  
Low Velocity

Experimental investigation of nanoparticles precipitation in a rotating packed bed

Particuology ◽  
2010 ◽  
Vol 8 (4) ◽  
pp. 372-378 ◽  
Author(s):  
Xiang Yang ◽  
Guangwen Chu ◽  
Lixiong Wen ◽  
Kuang Yang ◽  
Guangting Xiao ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Packed Bed ◽  
Rotating Packed Bed

Extension of the Combustion Stability Range in Dry Low NOx Lean Premixed Gas Turbine Combustor Using a Fuel Rich Annular Pilot Burner

2014 ◽  
Vol 136 (5) ◽  
Author(s):  
L. Rosentsvit ◽  
Y. Levy ◽  
V. Erenburg ◽  
V. Sherbaum ◽  
V. Ovcharenko ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Combustion Zone ◽  
Combustion Instability ◽  
Experimental Results ◽  
Nox Emission ◽  
Combustion Stability ◽  
Stability Range ◽  
Numerical Effort ◽  
Lean Premixed ◽  
Pilot Burner

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.

The Histogram of Pressure Oscillations Amplitudes, in Lean Premixed Combustions, Caused by Thermo-Acoustic Instabilities

2010 ◽  
Author(s):  
Nasser Seraj Mehdizadeh ◽  
Nozar Akbari
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Equivalence Ratio ◽  
Combustion Instability ◽  
Premixed Combustion ◽  
Space Distribution ◽  
Rayleigh Criterion ◽  
Pressure Oscillations ◽  
Lean Premixed

Lean premixed combustion is widely used in recent years as a method to achieve the environmental standards with regard to NOx emission. In spite of the mentioned advantage, premixed combustion systems, with equivalence ratios less than one, are susceptible to the combustion instability. To study the lean combustion instability, by experiments, one premixed combustion setup, equipped with reactant supplying system, is designed and manufactured in Amirkabir University of Technology. In this research, gaseous propane is introduced as fuel and several experiments are performed at nearly atmospheric pressure, with equivalence ratios within the range of 0.7 to 1.5. In this experiments fuel mass flow rate is varied between 2 and 4 gr/s. Unstable operating condition has been observed in combustion chamber when equivalence ratio is less than one. To distinguish the combustion instability for various operating conditions, probability density functions, spectral diagrams, and space distribution of pressure oscillations, along with Rayleigh Criterion, are utilized. Accordingly, effect of equivalence ratio on stabilizing the unstable combustion system is investigated. Moreover, convective delay time is calculated for all experiments and the results are compared with Rayleigh Criterion. This comparison has shown good agreement the experimental results and Rayleigh Criterion. Finally, stability limits are identified based on inlet mass flow rate and equivalence ratio.

Experimental Investigation of Convective Melting of Granular Packed Bed Under Microgravity

2000 ◽  
Author(s):  
J. Jiang ◽  
Y. Hao ◽  
Y.-X. Tao
Keyword(s):  
Experimental Investigation ◽  
Average Particle Size ◽  
Particle Diameter ◽  
Vertical Direction ◽  
Packed Bed ◽  
Melting Rate ◽  
Control Flow ◽  
Solid Particles ◽  
Average Particle ◽  
Ice Particles

Abstract To improve the understanding of convective melting of packed solid particles in a fluid, an experimental investigation is conducted to study the melting characteristics of a packed bed by unmasking the buoyancy forces due to the density difference between the melt and solid particles. A close-loop apparatus, named the particle-melting-in-flow (PMF) module, is designed to allow a steady state liquid flow under a specified temperature. The module is on board NASA’s KC-135 reduced gravity aircraft for the experiments. In the test module, water is used as the fluid, and ice particles are fed to the test section at the beginning of the test. As the liquid flows though the bed, the solid grains melt. A perforate plate, through which liquid can flow while the ice particles are retained, bounds the downstream of the packed bed. From the digital video images the local packed bed thickness is measured under control flow rate, and the melting rate is determined. The temperature distribution along the horizontal direction and vertical direction is measured using 19 thermocouples. An infrared camera is mounted to record the local temperature variation between liquid and solid. The melting rates are presented as a function of upstream flow velocity, temperature and initial average particle size of the packed bed. It is found that the melting rate is influenced mainly by the ratio of the Reynolds number (Re, based on the initial particle diameter) to the square of the Froud number (Fr), and me Stefan number (Ste). In general, the dimensionless melting rate decreases as Re/Fr2 increases and increases as Ste increases. With the absence of gravity, i.e., Froud number approaches infinity, a maximum melting rate can be achieved for otherwise the same test conditions. The increase in the melting rate with the increase in Stephan number also becomes more pronounced under the zero gravity condition.

Experimental investigation on effects of injection distribution on combustion instability in a model rocket combustor

2022 ◽  
Vol 34 (1) ◽  
pp. 011702
Author(s):  
Kangkang Guo ◽  
Lei Ni ◽  
Yongjie Ren ◽  
Wei Lin ◽  
Yiheng Tong ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Combustion Instability

Experimental investigation on the packed bed of rodlike particles

2019 ◽  
Vol 30 (11) ◽  
pp. 2541-2547 ◽  
Author(s):  
Wenguang Nan ◽  
Yueshe Wang ◽  
Houhuan Sun
Keyword(s):  
Experimental Investigation ◽  
Packed Bed ◽  
Rodlike Particles
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