scholarly journals Model and Experiment on Resistance Loss of Wet Chordal Grid with Spray Pressure and Structural Parameters

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Hua Guo ◽  
Haiqiao Wang ◽  
Zhirong Wu
Keyword(s):  
Wind Speed ◽  
Structural Parameters ◽  
Steel Wire ◽  
Water Film ◽  
Resistance Coefficient ◽  
Dust Removal ◽  
Filling Rate ◽  
Wind Speeds ◽  
Vibrating String ◽  
Relationship Of

To reduce the dedusting resistance of wet vibrating string grille precipitators during dedusting in mine ventilation roadways, we investigated the dedusting resistance characteristics of water fog and water film coupling and determined the relationship between dedusting resistance and spray pressure, vibrating grid filling rate, and wind speed. A mathematical resistance coefficient model is established using hydrodynamics theory and capillary mechanics. The theoretical relationship of dedusting resistance is deduced. The results show that when wind speed is constant, the spray pressure and dedusting resistance are higher and the resistance is smaller with a high filling rate compared with a low filling rate. Constant spray pressure allows faster wind speeds and reverse pressure gradient forces to increase when dust flows around the wet vibrating wire, which makes the pressure distribution asymmetrical around the steel wire and increases resistance. Dust removal resistance of the resonance chord with a high filling rate is substantially lower than that with a low filling rate under the same working conditions. On the basis of satisfying the dedusting efficiency, the resonance chord dedusting system does not affect normal production and resistance is low. The spray pressure is controlled at 0.3–0.7 MPa and the optimal wind speed is 3–4 m/s. According to the theoretical calculation and experimental data, the optimal filling rate of a vibrating string grid plate is 77.8%, spray pressure is 0.7 MPa, and wind speed is 3.5 m/s. Dust removal with low resistance and improved economic benefit can thus be obtained.

scholarly journals Wind Speed Influences on Marine Aerosol Optical Depth

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Colin O'Dowd ◽  
Claire Scannell ◽  
Jane Mulcahy ◽  
S. Gerard Jennings
Keyword(s):  
Wind Speed ◽  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Power Law ◽  
Anthropogenic Pollution ◽  
Open Ocean ◽  
Marine Aerosol ◽  
Wind Speeds ◽  
General Power ◽  
Relationship Of

The Mulcahy (Mulcahy et al., 2008) power-law parameterization, derived at the coastal Atlantic station Mace Head, between clean marine aerosol optical depth (AOD) and wind speed is compared to open ocean MODIS-derived AOD versus wind speed. The reported AOD versus wind speed (U) was a function of ∼U2. The open ocean MODIS-derived AOD at 550 nm and 860 nm wavelengths, while in good agreement with the general magnitude of the Mulcahy parameterization, follows a power-law with the exponent ranging from 0.72 to 2.47 for a wind speed range of 2–18 m s−1. For the four cases examined, some MODIS cases underestimated AOD while other cases overestimated AOD relative to the Mulcahy scheme. Overall, the results from MODIS support the general power-law relationship of Mulcahy, although some linear cases were also encountered in the MODIS dataset. Deviations also arise between MODIS and Mulcahy at higher wind speeds (>15 m s−1), where MODIS-derived AOD returns lower values as compared to Mulcahy. The results also support the suggestion than wind generated sea spray, under moderately high winds, can rival anthropogenic pollution plumes advecting out into marine environments with wind driven AOD contributing to AOD values approaching 0.3.

Piezoelectric Clamped Beam Energy Harvester Using Vibration Caused by Centrifugal Force at High Wind Speeds

2019 ◽  
Vol 4 (1) ◽  
pp. 41-46 ◽  
Author(s):  
Da Xiao ◽  
Ying Yang ◽  
Qinlong Shen ◽  
Jiamei Jin ◽  
Yiping Wang
Keyword(s):  
Wind Speed ◽  
Wind Energy ◽  
Centrifugal Force ◽  
High Speed ◽  
Energy Harvester ◽  
Structural Parameters ◽  
Electrical Energy ◽  
Open Circuit ◽  
Wind Speeds ◽  
Peak Output Power

Abstract In this study, a piezoelectric wind energy harvester was vibrated that aims to convert high-speed wind energy into electrical energy using vibrations caused by centrifugal force. Vibrations induced by centrifugal force enabled effective distortion of the piezoelectric clamped beam and thus produced electric charge through the piezoelectric effect. A clamped beam was used rather than a conventional thin cantilever to harvest the wind energy in the proposed harvester. The centrifugal force was introduced by a pair of rotating eccentric turbines that are installed on two ball bearings on both sides of the piezoelectric unimorph. Benefiting from the rotating eccentric masses of these turbines, the harvester is capable of capturing wind energy in high speed wind environments. A prototype was set up to examine the effects of the wind speed and the structural parameters on the electrical output of the harvester. It is found that the harvester worked efficiently with wind applied from the axial directions in a 20–55 m/s speed range and produced a maximum open-circuit voltage of 47.2 V. When connected to an external load of 50 kΩ, the harvester showed a peak output power of 3.69 mW at a wind speed of 55 m/s.

scholarly journals Study on the Atomization and Dust-Reduction Performance of a New Type of External Pneumatic Vortex Fog Curtain Dust Removal Device in Fully Mechanized Excavation Face

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Deji Jing ◽  
Rina An ◽  
Jingxu Chen ◽  
Shaocheng Ge ◽  
Liying Sun
Keyword(s):  
Wind Speed ◽  
Dust Removal ◽  
Air Volume ◽  
Reduction Experiment ◽  
Reduction Efficiency ◽  
New Type ◽  
Atomization Performance ◽  
Relationship Of ◽  
Atomization Pressure ◽  
Dust Reduction

To solve the problem of dust pollution in the heading face, a new type of external pneumatic vortex fog curtain dust removal device suitable for a fully mechanized excavation face is designed in this paper. Firstly, dust migration laws at different times are simulated and analyzed by COMSOL software, and the functional relationship of dust concentration distribution above 50 mg/m3 at different heights and different wind speed is derived. Aiming at the dust migration laws of the heading face, a new dust removal device was proposed, and the atomization performance of the new type of external pneumatic vortex fog curtain dust removal device under different jet wind speed, different atomization pressure, and different nozzle working angle is explored through atomization performance experiment. It is found that when jet wind speed is 30 m/s, atomization pressure is 4 MPa, and nozzle working angle is 75°, the atomization performance of the new type of external pneumatic vortex fog curtain dust removal device is the best. Through the simulation of COMSOL software, the influence of air volume on the new type of external pneumatic vortex fog curtain dust removal device is analyzed. It is found that the new type of external pneumatic vortex fog curtain dust removal device is relatively stable when the air volume at the pressure outlet is less than 400 m3/min. The dust-reduction efficiency of the new type of external pneumatic vortex fog curtain dust removal device was investigated through the dust-reduction experiment, and it is found that the new type of external pneumatic vortex fog curtain dust removal device had better dust removal performance under the condition that the ventilation conditions did not interfere with the integrity of the vortex fog curtain.

scholarly journals Theoretical and experimental study on the effective area of water film and dust removal efficiency

2020 ◽  
Author(s):  
hua guo ◽  
hai qiao Wang ◽  
shi qiang Chen ◽  
zhi rong Wu
Keyword(s):  
Liquid Film ◽  
Removal Efficiency ◽  
Water Film ◽  
Effective Area ◽  
Calculation Model ◽  
Dust Control ◽  
Dust Removal ◽  
Vibrating Wire ◽  
Spacing Ratio ◽  
Vibrating String

Abstract Breaking through the bottleneck of low resistance and high efficiency in mine exhaust dust control has been a hot issue in the industry. Aiming at the key problems of wet vibrating string grille dust removal, based on the multiphase flow theory and capillary mechanics, the dimensionless bond number expression of the influence of vibrating wire spacing on droplet spreading is derived. Furthermore, a liquid film formed by spreading droplets based on Kelvin correlation, young Laplace formula and Hagen Poiseuille theory, a formula for calculating the thickness and height of liquid film is established with temperature, relative humidity and molar volume of liquid phase as independent variables. Then, the dust removal efficiency calculation model of vibrating wire group is established between the liquid film thickness, height, wire diameter, effective water film area and vortex shedding frequency. Finally, on the experimental platform, the influence of the effective area of water film on the dust removal efficiency of wet vibrating wire grille plate is measured, and the above calculation model is verified. Moreover, the optimized combination of wet vibrating string spacing ratio 1.14, wind speed 3m/s and spray pressure 0.7 MPa is found, which provides important reference for engineering application.

MODEL ANALYSIS OF HIGH-RISE STRUCTURES FOR WIND AND EARTHQUAKE FORCES

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Vankudothu Bhikshma ◽  
Mohammed Hamraj ◽  
Ruttal Tejaswini
Keyword(s):  
Wind Speed ◽  
Static Analysis ◽  
Structural Parameters ◽  
Model Analysis ◽  
Earthquake Loads ◽  
Wind Speeds ◽  
High Rise ◽  
Seismic Zones ◽  
Wind Velocities ◽  
Zone Ii

The objective of the present work is to study and analyze the effect of wind and earthquake loads on a chosen symmetrical plan of a multi-storied building to assess the behavior of the structure in all the seismic zones based on IS 1893 and subjected to different wind velocities based on IS 875 codes. For the present study, six cases (6 floors, 9 floors and 12 floors each for earthquake and wind) are considered under which 30 structures are modelled in ETABSv16.0 software and static analysis is carried out. Structural parameters like story drifts, story displacements and story shears are studied. Finally, it is found that story drifts are found to be maximum at 2nd floor (i.e., at 6 m) and 40% increase is observed in parameters when wind speed is increased from 33 to 39 m/s and by 21% when wind speed is increased from 50 to 55 m/s. With increase in wind speed on moving to higher seismic zones, with increase in number of stories from 6 to 9 story drifts increased by 109%, story displacements increased by 185% and increased by 15% and 62% on moving to higher seismic zones. Also, wind forces on the structure subjected to variation in increasing wind speeds and increasing heights in zone II and zone III but in no case are they greater than the earthquake forces in zone IV and V.

SHAPING OF AN AUTONOMOUS POWER SYSTEM FOR GUARANTEED POWER SUPPLY WITH THE PREDOMINANCE WIND ENERGY

2018 ◽  
pp. 28-50
Author(s):  
S. G. Ignatiev ◽  
S. V. Kiseleva
Keyword(s):  
Energy Storage ◽  
Wind Speed ◽  
Wind Energy ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Energy Demand ◽  
Diesel Generator ◽  
Average Wind Speed ◽  
Wind Speeds ◽  
Average Wind

Optimization of the autonomous wind-diesel plants composition and of their power for guaranteed energy supply, despite the long history of research, the diversity of approaches and methods, is an urgent problem. In this paper, a detailed analysis of the wind energy characteristics is proposed to shape an autonomous power system for a guaranteed power supply with predominance wind energy. The analysis was carried out on the basis of wind speed measurements in the south of the European part of Russia during 8 months at different heights with a discreteness of 10 minutes. As a result, we have obtained a sequence of average daily wind speeds and the sequences constructed by arbitrary variations in the distribution of average daily wind speeds in this interval. These sequences have been used to calculate energy balances in systems (wind turbines + diesel generator + consumer with constant and limited daily energy demand) and (wind turbines + diesel generator + consumer with constant and limited daily energy demand + energy storage). In order to maximize the use of wind energy, the wind turbine integrally for the period in question is assumed to produce the required amount of energy. For the generality of consideration, we have introduced the relative values of the required energy, relative energy produced by the wind turbine and the diesel generator and relative storage capacity by normalizing them to the swept area of the wind wheel. The paper shows the effect of the average wind speed over the period on the energy characteristics of the system (wind turbine + diesel generator + consumer). It was found that the wind turbine energy produced, wind turbine energy used by the consumer, fuel consumption, and fuel economy depend (close to cubic dependence) upon the specified average wind speed. It was found that, for the same system with a limited amount of required energy and high average wind speed over the period, the wind turbines with lower generator power and smaller wind wheel radius use wind energy more efficiently than the wind turbines with higher generator power and larger wind wheel radius at less average wind speed. For the system (wind turbine + diesel generator + energy storage + consumer) with increasing average speed for a given amount of energy required, which in general is covered by the energy production of wind turbines for the period, the maximum size capacity of the storage device decreases. With decreasing the energy storage capacity, the influence of the random nature of the change in wind speed decreases, and at some values of the relative capacity, it can be neglected.

scholarly journals Loading Performance of a Novel Shearer Drum Applied to Thin Coal Seams

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 358
Author(s):  
Kuidong Gao ◽  
Xiaodi Zhang ◽  
Liqing Sun ◽  
Qingliang Zeng ◽  
Zhihai Liu
Keyword(s):  
Rotational Speed ◽  
Production Efficiency ◽  
Loading Rate ◽  
Positive Impact ◽  
Structural Parameters ◽  
Helix Angle ◽  
Structure Design ◽  
Coal Seams ◽  
Coal Particles ◽  
Relationship Of

The poor loading performance of shearer drums restricts the development and production efficiency of coal in thin coal seams. Changing operation and structural parameters can improve the drum’s loading performance to some extent, but the effect is not obvious. A two-segment differential rotational speed drum (TDRSD) was proposed after analyzing the drum’s influence mechanism on coal particles. To further reveal the drum’s coal loading principle, the velocity, particles distribution, and loading rate were analyzed. The effect of the matching relationship of the rotational speed and helix angle between the front and rear drum are also discussed. The results show that a lower front drum rotational speed had a positive impact on improving the loading performance, and the loading rate first increases and then decreases with the increase in rear drum rotational speed. The optimal loading performance was obtained in the range 60–67.5 rpm. The front drum’s helix angle had no evident effect on loading performance, and the loading rate increase with the increase in the rear drum’s helix angle. The results provide a reference and guidance for operation parameters selection, structure design, and drum optimization.

scholarly journals Analysis of Performance of the Wind-Driven Pulverizing Aerator Based on Average Wind Speeds in the Conditions of Góreckie Lake

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2796
Author(s):  
Andrzej Osuch ◽  
Ewa Osuch ◽  
Stanisław Podsiadłowski ◽  
Piotr Rybacki
Keyword(s):  
Mathematical Model ◽  
Wind Speed ◽  
Water Pump ◽  
Average Wind Speed ◽  
Flow Rates ◽  
Wind Speeds ◽  
Average Wind ◽  
Flow Through ◽  
Analysis Of Performance ◽  
Research Period

In the introduction to this paper, the characteristics of Góreckie lake and the construction and operation of the wind-driven pulverizing aerator are presented. The purpose of this manuscript is to determine the efficiency of the pulverizing aerator unit in the windy conditions of Góreckie Lake. The efficiency of the pulverization aerator depends on the wind conditions at the lake. It was necessary to conduct thorough research to determine the efficiency of water flow through the pulverization segment (water pump). It was necessary to determine the rotational speed of the paddle wheel, which depended on the average wind speed. Throughout the research period, measurements of hourly average wind speed were carried out. It was possible to determine the efficiency of the machine by developing a dedicated mathematical model. The latest method was used in the research, consisting of determining the theoretical volumetric flow rates of water in the pulverizing aerator unit, based on average hourly wind speeds. Pulverization efficiency under the conditions of Góreckie Lake was determined based on 6600 average wind speeds for spring, summer and autumn, 2018. Based on the model, the theoretical efficiency of the machine was calculated, which, under the conditions of Góreckie Lake, amounted to 75,000 m3 per year.

scholarly journals Optimization of a Small Wind Power Plant for Annual Wind Speed Distribution

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1587
Author(s):  
Krzysztof Wrobel ◽  
Krzysztof Tomczewski ◽  
Artur Sliwinski ◽  
Andrzej Tomczewski
Keyword(s):  
Wind Speed ◽  
Power Plant ◽  
Wind Power ◽  
Power Plants ◽  
Control Method ◽  
Wind Power Plant ◽  
Switched Reluctance ◽  
Wind Speeds ◽  
Wind Speed Distribution ◽  
And Control

This article presents a method to adjust the elements of a small wind power plant to the wind speed characterized by the highest annual level of energy. Tests were carried out on the basis of annual wind distributions at three locations. The standard range of wind speeds was reduced to that resulting from the annual wind speed distributions in these locations. The construction of the generators and the method of their excitation were adapted to the characteristics of the turbines. The results obtained for the designed power plants were compared with those obtained for a power plant with a commercial turbine adapted to a wind speed of 10 mps. The generator structure and control method were optimized using a genetic algorithm in the MATLAB program (Mathworks, Natick, MA, USA); magnetostatic calculations were carried out using the FEMM program; the simulations were conducted using a proprietary simulation program. The simulation results were verified by measurement for a switched reluctance machine of the same voltage, power, and design. Finally, the yields of the designed generators in various locations were determined.

scholarly journals A Novel Sea Surface Roughness Parameterization Based on Wave State and Sea Foam

2021 ◽  
Vol 9 (3) ◽  
pp. 246
Author(s):  
Difu Sun ◽  
Junqiang Song ◽  
Xiaoyong Li ◽  
Kaijun Ren ◽  
Hongze Leng
Keyword(s):  
Surface Roughness ◽  
Wind Speed ◽  
Drag Coefficient ◽  
Sea Surface ◽  
High Wind Speed ◽  
Wave State ◽  
Wind Speeds ◽  
Sea Surface Roughness ◽  
Extreme Wind ◽  
The Impact

A wave state related sea surface roughness parameterization scheme that takes into account the impact of sea foam is proposed in this study. Using eight observational datasets, the performances of two most widely used wave state related parameterizations are examined under various wave conditions. Based on the different performances of two wave state related parameterizations under different wave state, and by introducing the effect of sea foam, a new sea surface roughness parameterization suitable for low to extreme wind conditions is proposed. The behaviors of drag coefficient predicted by the proposed parameterization match the field and laboratory measurements well. It is shown that the drag coefficient increases with the increasing wind speed under low and moderate wind speed conditions, and then decreases with increasing wind speed, due to the effect of sea foam under high wind speed conditions. The maximum values of the drag coefficient are reached when the 10 m wind speeds are in the range of 30–35 m/s.

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