scholarly journals Some Effects on the Temperature of the Mine Air at the Heading Face

2021 ◽  
Vol 1 (2) ◽  
Author(s):  
Van Quang NGUYEN ◽  
Van Thinh NGUYEN ◽  
Cao Khai NGUYEN ◽  
Van Chung PHAM
Keyword(s):  
Numerical Simulation ◽  
High Temperature ◽  
Temperature Distribution ◽  
Air Temperature ◽  
Significant Influence ◽  
Thermal Environment ◽  
Simulation Method ◽  
Forced Ventilation ◽  
Ansys Cfx ◽  
Ventilation Method

Currently, with the increase in mining output leading to deeper mining levels, the volume ofheading face serving production has also increased. The thermal environment tends to worsen whendigging deep due to the geothermal's effect, which increases the air temperature at the heading face.According to QCVN01/2011-BCT, the temperature at the heading face is not allowed to exceed 300C. Toensure this, in Vietnam today, mainly forced ventilation method uses local fans to provide a clean amountof air to ensure a favorable environment for workers. With the forced ventilation method, the duct positionis usually arranged on the side, and the distance from the duct mouth to the heading face is determined toensure that l < 6√s. In this study, a numerical simulation method by Ansys CFX software is applied tostudy the influence of several factors such as duct position, air temperature of duct, and roughnesscharacteristics of roadway on the temperature of the mine air at the heading face. The models are set upwith six duct positions and four air temperature of duct parameters. Model 1 (y =1.1 m) is better thanmodels 2 to 6 in terms of temperature distribution and the lowest temperature values. Four models havedifferent wind temperatures, and we can see the significant influence of the inlet air temperature of theduct on the thermal environment of the heading face. The results show that with the model T = 297.15K,the temperature value on the roadway length is guaranteed as specified < 303K. The result is a referencefor determining the duct position and cool for the high-temperature heading face.

scholarly journals Study on the Thermal Environment Inside a Fully-Enclosed Subway Noise Barrier

2020 ◽  
Vol 143 ◽  
pp. 01044
Author(s):  
Lei Liu ◽  
Lianghan Zhang ◽  
Zhongxu Kang ◽  
Kun Yao
Keyword(s):  
Numerical Simulation ◽  
Comparative Analysis ◽  
Air Temperature ◽  
Thermal Environment ◽  
Simulation Method ◽  
Internal Environment ◽  
Numerical Simulation Method ◽  
Calculation Results ◽  
Noise Barrier ◽  
Air Vent

The thermal environment inside a fully-enclosed subway noise barrier shall be designed according to underground section tunnel standards. This article constructs a model using practical examples, simulates calculations on fully-enclosed noise barrier installations both with and without air vents via a threedimensional numerical simulation method, and then conducts a comparative analysis of the effects noise barrier lengths and air vent widths have on an internal thermal environment. The calculation results show that when the length of the fully-enclosed noise barrier without air vents was 100m, the internal thermal environment exceeded the limit; as the width of the air vents increased, the temperature in the internal environment gradually decreased, but the reduction was less once the air vent width exceeded 2 m; When the top air vent width was 2 m, and the noise barrier length was 100m, the thermal environment was found to meet requirements. As the noise barrier length increased, the internal air temperature exceeded the standards by varying degrees.

Numerical Simulation of Effects of Spray Angle on Flow, Combustion and Emissions of Diesel Engine

2014 ◽  
Vol 488-489 ◽  
pp. 1064-1069
Author(s):  
Da Guang Li ◽  
Zhang Ying ◽  
Xiu Qing Zhu
Keyword(s):  
Numerical Simulation ◽  
High Temperature ◽  
Diesel Engine ◽  
Significant Influence ◽  
Release Rate ◽  
Temperature Increase ◽  
Simulation Method ◽  
Spray Angle ◽  
Cylinder Pressure ◽  
Performance And Emissions

Previous papers which researched the effects of spray angle were mainly focused on the influence of spray angle on the performance and emissions of diesel engine. Few papers clarified the effect of spray angle on the airflow in detail. Airflow and turbulence have a significant influence on the combustion and distribution of emissions.The effects of spray angle on the flow, combustion and emissions of diesel engine were studied in this paper by a numerical simulation method. The results indicated that the spray angle had an obvious impact on the vortex and turbulence. The distribution of high temperature areas and emissions depend on the vortex and turbulence. With the increase of spray angle, the maximum cylinder pressure and temperature increase gradually. The heat release rate increases with the increase of spray angle. The CO and soot emissions were the lowest when the spray angle is 155°, however, the NOx emissions was the highest at that spray angle.

Numerical Simulation of Airflow Patterns and Air Temperature Distribution during Inspiration in a Nose Model with Septal Perforation

2004 ◽  
Vol 18 (6) ◽  
pp. 357-362 ◽  
Author(s):  
Daniela Pless ◽  
Tilman Keck ◽  
Kerstin M. Wiesmiller ◽  
Ralf Lamche ◽  
Andrik J. Aschoff ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Temperature Distribution ◽  
Air Temperature ◽  
Septal Perforation

Numerical Simulation of High-Temperature Air Direct-Ignition of Pulverized Coal

2005 ◽  
Author(s):  
Z. Z. Kang ◽  
B. M. Sun ◽  
Y. H. Guo ◽  
W. Zhang ◽  
H. Q. Wei
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
High Temperature ◽  
Simulation Method ◽  
Pulverized Coal ◽  
Inlet Velocity ◽  
Operation Optimization ◽  
Structure Improvement ◽  
Simulation Results ◽  
Direct Ignition

Numerical simulation method is employed in this article to investigate various high-temperature air direct-ignition processes of pulverized coal (PC). Several important factors are analyzed, which are the inlet velocity of primary air flow, PC concentration and the velocity and temperature of high temperature air. The flow, combustion and heat transfer in high temperature air oil-free ignition burner can also be obtained from the simulation results, which are in accordance with the experimental data. The research provides guidance for structure improvement and operation optimization of burner.

Numerical Simulation on Blasting Fume Diffusion in Blind Roadway with FLUENT

2013 ◽  
Vol 663 ◽  
pp. 655-660
Author(s):  
Zhen Hua Xie ◽  
Zheng Lan Yuan ◽  
Yu Zhang
Keyword(s):  
Numerical Simulation ◽  
Simulation Method ◽  
Mining Area ◽  
Computational Grids ◽  
Actual Situation ◽  
Forced Ventilation ◽  
Iron Mine ◽  
Effective Ventilation ◽  
Set Up ◽  
And Diffusion

Aiming at the generation of blasting fume in underground blind roadway, numerical simulation method was taken to obtain the diffusion law of the blasting fume. In accordance with the actual situation in Shachang mining area of Shouyun iron mine, the physical model and mathematical model were set up, computational grids were divided, and the boundary condition was established. The diffusion law of blasting fume and the completion time under different explosives dosage were simulated by Fluent. The laws of blasting fume diffusion and diffusion time changing with the amount of explosive in local fan forced ventilation were obtained. The results can provide a theoretical basis for the research of a reasonable and effective ventilation manner of blind roadway.

Research on the Effect of Natural Ventilation on Buses in Summer Based on CFD Numerical Simulation Method

2011 ◽  
Vol 361-363 ◽  
pp. 1056-1060 ◽  
Author(s):  
Bao Lin ◽  
Xue Ting Wang ◽  
Xiao Hu
Keyword(s):  
Numerical Simulation ◽  
Thermal Comfort ◽  
Natural Ventilation ◽  
Thermal Environment ◽  
Air Flow ◽  
Cost Effective ◽  
Simulation Method ◽  
Computational Domain ◽  
Cfd Numerical Simulation ◽  
Different Parts

Because of the relatively narrow space and high density distribution of the passengers, the bus interior environment deteriorates in summer. Natural ventilating introduces a fresh natural freeze, provides the bus interior with appropriate distribution of air supply temperature and velocity field. Making good use of natural ventilation is an operating strategy ideal for improving passengers’ satisfaction, which is considered as an environmental friendly and cost effective approach. Based on CFD numerical simulation, with a whole-domain approach, this paper predicts air flow and thermal comfort in naturally ventilated bus. The outside and inside airflow is modelled simultaneously and within the same computational domain. The thermal environment in different parts of the bus interior is compared. Different vehicle velocities and conditions of windows are taken into account, analysis are made regarding to the effect of both of them on the interior thermal comfort. The result shows, air disturbance at the bus rear parts are intenser than the other parts with better thermal satisfaction; the quality of air flow in different parts makes the temperature difference in bus achieve as high as 3°C; the use of roof openings distributes the temperature more evenly.

scholarly journals Prediction and Evaluation of Dynamic Variations of the Thermal Environment in an Air-Conditioned Room Using Collaborative Simulation Method

Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5378
Author(s):  
Lin He ◽  
Shunan Zhao ◽  
Guowen Xu ◽  
Xin Wu ◽  
Junlong Xie ◽  
...  
Keyword(s):  
Air Temperature ◽  
Temperature Difference ◽  
Thermal Environment ◽  
Structural Parameters ◽  
Simulation Method ◽  
Outer Diameter ◽  
Control Parameters ◽  
Temperature Uniformity ◽  
Collaborative Simulation ◽  
Dynamic Variations

In this study, a collaborative simulation method is proposed to predict dynamic variations of the thermal environment in an air-conditioned room. The room thermal environment was predicted and analyzed by varying the structural and control parameters of the air conditioner considering the dynamic coupling effect. Connections and regularities were established between the applicable parameters and evaluation indices of the thermal environment. The simulation results demonstrated the interactions among the system structural parameters, control parameters, and the thermal environment. Within a certain parameter range, the evaporator structure exhibited a significant effect on temperature uniformity and vertical air temperature difference, followed by predicted mean vote (PMV) and draught rate (DR). The associated evaluation indices were sensitive to fin spacing, tube spacing, and tube outer diameter, in the same order, which were structural parameters of the evaporator. The effect of the air supply angle on the vertical air temperature difference was evident; however, its influence on the PMV, DR, and temperature uniformity did not indicate consistent variations.

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