scholarly journals Investigation of the direct-flow jets vortex motion in the M-shaped boiler invert furnace

2021 ◽  
Vol 2088 (1) ◽  
pp. 012036
Author(s):  
V B Prokhorov ◽  
V S Kirichkov ◽  
S L Chernov ◽  
A A Kaverin ◽  
N E Fomenko
Keyword(s):  
High Efficiency ◽  
Coal Dust ◽  
Dynamic Pressure ◽  
Vortex Motion ◽  
Turbulent Jets ◽  
Flame Length ◽  
Dust Particles ◽  
Direct Flow ◽  
Horizontal Section ◽  
Vortex Furnace

Abstract For advanced ultra-supercritical parameters (A-USC) of steam, the design of an M-shaped boiler is proposed, designed to operate in a 500 MW unit on a lean coal (grade TR). The boiler profile is selected from the condition of minimizing the length of the main steamlines made of expensive nickel-alloy steel. With regard to this boiler, a scheme has been developed for pulverized coal combustion in an invert furnace using direct-flow burners and nozzles. Research has been carried out on the physical model of the furnace in the implementation of this combustion scheme: a qualitative study of the trajectories of the burner jets, jets of secondary and tertiary air obtained by their hot spark visualization; quantitative determination of the main characteristics of burner jets and their weight gain. The studies have shown the high efficiency of the recommended scheme of the furnace-burner device: a staged supply of the oxidizer along the flame length and along the furnace height is organized; the dynamic pressure of jets on the furnace wall tubes is excluded; vortex furnace aerodynamics should provide a high degree of burnout of coal dust particles; air jets evenly fill the horizontal section of the furnace; the ejection capacity of turbulent jets is much higher than for a flat submerged jet.

A VGGNet-like approach for classifying and segmenting coal dust particles with overlapping regions

2021 ◽  
Vol 132 ◽  
pp. 103506
Author(s):  
Zheng Wang ◽  
Xu Zheng ◽  
Dongyan Li ◽  
Helin Zhang ◽  
Yi Yang ◽  
...  
Keyword(s):  
Coal Dust ◽  
Dust Particles

COMBUSTION OF A GAS SUSPENSION OF COAL DUST IN A SWIRLING FLOW

2021 ◽  
pp. 139-147
Author(s):  
K.M. Moiseeva ◽  
◽  
A.Yu. Krainov ◽  
E.I. Rozhkova ◽  
◽  
...  
Keyword(s):  
Flow Velocity ◽  
Swirling Flow ◽  
Coal Dust ◽  
Combustion Efficiency ◽  
Dust Particles ◽  
Gas Temperature ◽  
Flow Swirl ◽  
Angular Component ◽  
Air Suspension ◽  
The Impact

Swirling combustion is currently one of the most important engineering problems in physics of combustion. There is a hypothesis on the increase in the combustion efficiency of reacting gas mixtures in combustion chambers with swirling flows, as well as on the increase in the efficiency of fuel combustion devices. In this paper, it is proposed to simulate a swirling flow by taking into account the angular component of the flow velocity. The aim of the study is to determine the effect of the angular component of the flow velocity on the characteristics of the flow and combustion of an air suspension of coal dust in a pipe. The problem is solved in a twodimensional axisymmetric approximation with allowance for a swirling flow. A physical and mathematical model is based on the approaches of the mechanics of multiphase reacting media. A solution method involves the arbitrary discontinuity decay algorithm. The impact of the flow swirl and the size of coal dust particles on the gas temperature distribution along the pipe is determined.

Respirable Coal Dust Particles Modify Cytochrome P4501A1 (CYP1A1) Expression in Rat Alveolar Cells

2004 ◽  
Vol 31 (2) ◽  
pp. 171-183 ◽  
Author(s):  
Mohamed M. Ghanem ◽  
Dale Porter ◽  
Lori A. Battelli ◽  
Val Vallyathan ◽  
Michael L. Kashon ◽  
...  
Keyword(s):  
Coal Dust ◽  
Dust Particles ◽  
Alveolar Cells ◽  
Cytochrome P4501a1 ◽  
Cyp1a1 Expression

scholarly journals Investigation of the interaction of turbulent jets in furnaces with direct-flow burners for high-power boilers

2020 ◽  
Vol 1565 ◽  
pp. 012024
Author(s):  
V S Kirichkov ◽  
V B Prokhorov ◽  
S L Chernov ◽  
A A Kaverin
Keyword(s):  
High Power ◽  
Turbulent Jets ◽  
Direct Flow

scholarly journals Development of Environmental Friendly Dust Suppressant Based on the Modification of Soybean Protein Isolate

Processes ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 165 ◽  
Author(s):  
Hu Jin ◽  
Wen Nie ◽  
Yansong Zhang ◽  
Hongkun Wang ◽  
Haihan Zhang ◽  
...  
Keyword(s):  
Water Retention ◽  
Soybean Protein ◽  
Coal Dust ◽  
Sodium Dodecyl ◽  
Environmentally Friendly ◽  
Protein Isolate ◽  
Dust Particles ◽  
Dust Suppression ◽  
Soybean Protein Isolate ◽  
Coal Particles

Aiming to further improve the dust suppression performance of the dust suppressant, the present study independently develops a new type of biodegradable environmentally-friendly dust suppressant. Specifically, the naturally occurring biodegradable soybean protein isolate (SPI) is selected as the main material, which is subject to an anionic surfactant, i.e., sodium dodecyl sulfonate (SDS) for modification with the presence of additives including carboxymethylcellulose sodium and methanesiliconic acid sodium. As a result, the SDS-SPI cementing dust suppressant is produced. The present study experimentally tests solutions with eight different dust suppressant concentrations under the same experimental condition, so as to evaluate their dust suppression performances. Key metrics considered include water retention capability, cementing power and dust suppression efficiency. The optimal concentration of dust suppressant solution is determined by collectively comparing these metrics. The experiments indicate that the optimal dust suppressant concentration is 3%, at which level the newly developed environmentally-friendly dust suppressant solution exhibits a decent dust suppression characteristic, with the water retention power reaching its peak level, and the corresponding viscosity being 12.96 mPa·s. This performance can generally meet the requirements imposed by coal mines. The peak efficiency of dust suppression can reach 92.13%. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to analyze the dust suppression mechanism of the developed dust suppressant. It was observed that a dense hardened shell formed on the surface of the pulverized coal particles sprayed with the dust suppressant. There is strong cementation between coal dust particles, and the cementation effect is better. This can effectively inhibit the re-entrainment of coal dust and reduce environmental pollution.

A Chronic Inhalation Toxicity Study of Diesel Engine Emissions and Coal Dust, Alone and Combined

1989 ◽  
Vol 8 (2) ◽  
pp. 345-375 ◽  
Author(s):  
T. R. Lewis ◽  
F. H.Y. Green ◽  
W. J. Moorman ◽  
J. R. Burg ◽  
D. W. Lynch
Keyword(s):  
Body Weight ◽  
Diesel Engine ◽  
Diesel Exhaust ◽  
Coal Dust ◽  
Ambient Air ◽  
Female Rats ◽  
Dust Particles ◽  
Engine Emissions ◽  
Diesel Particulate ◽  
Diesel Engine Emissions

To evaluate the potential health hazards of diesel engine emissions in underground coal mines, inhalation studies were performed using three species of animals. A wide range of toxicological responses was measured. Exhaust was provided by a 425 in.3 displacement four-cycle, water-cooled, naturally aspirated diesel engine (Caterpillar Model 3304) equipped with a water scrubber. Exposures were 7 h/day, 5 days/week, for periods up to 24 months. Micronized coal dust was generated using a Wright dust feeder. Four exposures were evaluated: (1) filtered ambient air, (2) 2 mg/m3 diesel particulate, (3) 2 mg/m3 respirable coal dust, and (4) 1 mg/m3 each of 2 and 3. Gaseous and vapor concentrations were similar in both exposures employing diesel exhaust. Male cynomolgus monkeys, Fischer-344 male and female rats, and female CD-1 mice were the experimental subjects. Monkeys were sacrificed at 24 months, rats at 3, 6, 12, and 24 months, and mice at 1, 3, and 6 months. Gross morphology and histopathology demonstrated that both diesel and coal dust particles are deposited in the lungs and retained in alveolar tissue. Alveolar type II cell hyperplasia and pulmonary lipidosis occurred in rats, being most evident in rats exposed to diesel exhaust alone. There was, however, no evidence of emphysema or chronic bronchitis, and only minimal fibrosis was seen in association with the retained particulate. Both particulates affected the defense mechanisms of the lung. Exposure to coal dust activated responses associated with phagocytosis, whereas exposure to diesel exhaust depressed them. Severity of influenza challenge increased concomitantly with decreased interferon production in diesel-exposed mice. Exposure to diesel emissions did not result in genotoxic effects as measured by increases in sister chromatid exchange, chromosomal aberrations, micronucleus testing, and urine genotoxic assays. Pulmonary function studies in monkeys showed mild obstructive airway disease in coal dust, diesel exhaust, and the combined exposed animals. This effect was most pronounced in monkeys exposed to diesel exhaust. Evidence of restrictive lung disease was not seen in any group. Clearance of F3O4 particles appeared to be stimulated by exposure to diesel exhaust in the first 3 months, but long-term clearance of diesel particulate appeared to be inhibited. No evidence was found for increases in tumorogenicity (rats) or induction of xenobiotic metabolizing enzymes in the lung or liver (rats). Humoral and cellular immunities were not significantly affected by exposure (rats). No adverse seminal effects were observed in monkeys exposed for 2 years. There was no frank evidence of chronic toxicity as demonstrated by changes in mortality, body weight gains, organ-body weight ratios, or clinical parameters in rats or monkeys. Synergistic effects between diesel exhaust and coal dust were not demonstrated.

Combustion Oscillation Analysis of Premixed Flames at Elevated Pressures

1998 ◽  
Author(s):  
Masaya Ohtsuka ◽  
Shohei Yoshida ◽  
Shin’ichi Inage ◽  
Nariyoshi Kobayashi
Keyword(s):  
Dynamic Pressure ◽  
Time Lag ◽  
Premixed Flames ◽  
Acoustic Resonance ◽  
Flame Length ◽  
Elevated Pressures ◽  
Oscillation Analysis ◽  
Analytical Formulas ◽  
Combustion Oscillation ◽  
Analytical Time

A new analytical time lag flame model based on Bloxidge’s flame model was introduced for calculating combustion oscillation of premixed flame to take into account the distribution of heat release rate and flame speed which was calculated by analytical formulas dependent on pressure, temperature, fuel-to-air ratio and velocity. The transfer matrix technique using the new flame model was applied to the calculation of acoustic resonance. To verify the model, combustion oscillation experiments were performed for methane-air premixed flames stabilized by a swirl burner at elevated pressures between 0.6–0.9MPa. Fluctuating pressure had the maximum peak at the specific value of fτf. Here f is the frequency of resonance and τf is the passing time of premixed gas through flame length. The analysis could simulate the dependency of fuel-to-air ratio and static pressure for dynamic pressure local peak.

scholarly journals A new multicopter-based unmanned aerial system for pollen and spores collection in the atmospheric boundary layer

2019 ◽  
Vol 12 (3) ◽  
pp. 1581-1598 ◽  
Author(s):  
Claudio Crazzolara ◽  
Martin Ebner ◽  
Andreas Platis ◽  
Tatiana Miranda ◽  
Jens Bange ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Atmospheric Boundary Layer ◽  
High Efficiency ◽  
Aerosol Particles ◽  
Pollen Grains ◽  
Dust Particles ◽  
Unmanned Aerial System ◽  
Pollen Concentration ◽  
Concentration Data ◽  
Particle Collection

Abstract. The application of a new particle collection system (PCS) developed in-house and operated on board a commercially available multicopter unmanned aerial vehicle (UAV) is presented as a new unmanned aerial system (UAS) approach for in situ measurement of the concentration of aerosol particles such as pollen grains and spores in the atmospheric boundary layer (ABL). A newly developed impactor is used for high-efficiency particle extraction on board the multicopter UAV. An airflow volume of 0.2 m3 min−1 through the impactor is provided by a battery-powered blower and measured with an on-board mass flow sensor. A bell-mouth-shaped air inlet of the PCS is arranged and oriented on the multicopter UAV to provide substantial isokinetic sampling conditions by advantageously using the airflow pattern generated by the propellers of the multicopter UAV. More than 30 aerosol particle collection flights were carried out near Tübingen in March 2017 at altitudes of up to 300 m above ground level (a.g.l.), each with a sampled air volume of 2 m3. Pollen grains and spores of various genera, as well as large (>20 µm) opaque particles and fine dust particles, were collected, and specific concentrations of up to 100 particles per m3 were determined by visual microscopic analysis. The pollen concentration values measured with the new UAS match well with the pollen concentration data published by the Stiftung Deutscher Polleninformationsdienst (PID) and by MeteoSwiss. A major advantage of the new multicopter-based UAS is the possibility of the identification of collected aerosol particles and the measurement of their concentration with high temporal and spatial resolutions, which can be used inter alia to improve the database for modelling the propagation of aerosol particles in the ABL.

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