scholarly journals Numerical Simulation of Parameters Optimization for Goaf Gas Boreholes

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Jiajia Liu ◽  
Jianliang Gao ◽  
Ming Yang ◽  
Dan Wang ◽  
Liang Wang

In view of the ground drilling of the N2206 working face in Shanxi Wangzhuang Coal Mine, the gas concentration is low and the extraction effect is not good. Fluent computational fluid dynamics software was used to simulate the ground extraction drilling position of the N2206 working face in the goaf (the distance from the top of the coal seam and the distance from the return to the wind). The numerical simulation results show that when the final hole of the ground extraction hole in the goaf is 16 m from the roof of the coal seam and the distance from the return air is 45 m, the extraction effect is optimal. The average extraction gas volume is 9.78 m3/min, and the average extraction gas concentration is 43.95%, the best extraction effect is obtained. After optimizing the ground drilling position in the goaf and combining with the site implementation, the maximum gas scouring amount of the extraction is 12.59 m3/min, which is 3.42 m3/min higher than the original. The maximum gas concentration of extraction was 63.54%, which was 28.82% higher than the original. After optimization, the gas concentration of the extraction is more than 30%, and the extraction effect is very good. Field application results further validate the reliability of theoretical analysis and numerical simulation results.

2021 ◽  
pp. 014459872110635
Author(s):  
Wei Zhao ◽  
Wei Qin

Coal mining results in strata movement and surrounding rock failure. Eventually, manual mining space will be occupied by the destructed coal rock, making it difficult to conduct field tests of the coal seam to explore gas seepage and transport patterns. Therefore, computational fluid dynamics (CFD) numerical computation is an important tool for such studies. From the aspect of gas pre-drainage, for layer-through boreholes in the floor roadway of the 8,406 working face in Yangquan Mine 5 in China, reasonable layout parameters were obtained by CFD optimization. For effectively controlling the scope of boreholes along coal seam 9 in the Kaiyuan Mine, CFD computation was performed. The results revealed that the horizontal spacing between boreholes should be ≤2 m when a tri-quincuncial borehole layout is used. Optimization of the surface well position layout for the fault structure zone in the Xinjing Mine of the Yangquan mining area indicated that the horizontal distance between the surface well and the fault plane should be <150 m. From the aspect of gas drainage with mining-induced pressure relief, CFD computation was performed for pressure-relieved gas transport in the K8205 working face of Yangquan Mine 3. The results showed that forced roof caving should be used before the overhang length of hard roof reaches 25 m in the K8205 working face to avoid gas overrun. From the aspect of gas drainage from the abandoned gob, surface well control scopes at different surface well positions were computed, and an O-ring fissure zone is proposed as a reasonable scope for the surface well layout. CFD computation has been widely applied to coal and gas co-extraction in the Yangquan mining area and has played a significant role in guiding related gas drainage engineering practice.


2012 ◽  
Vol 532-533 ◽  
pp. 431-435
Author(s):  
Chong Zhi Mao ◽  
Qian Jian Guo ◽  
Lei He

Honeycomb ceramic is the key component of the regenerative system. The numerical simulation was performed using FLUENT, a commercial computational fluid dynamics (CFD) code, to compare simulation results to the test data. The regenerative process of a honeycomb ceramic regenerator was simulated under different conditions. Experiments were carried out on honeycomb regenerators that are contained in a methane oxidation reactor. The calculated temperatures of flue gas inlet were compared with the ones measured. The tendency of the temperature is the same as the experiment.


Author(s):  
Q Wu ◽  
Q Ye ◽  
G X Meng

This article introduces a new vortex gripper with a diversion body. Vortex gripper, as a pneumatic non-contact handling device, can generate lifting force to hold a workpiece without any contact. In order to predict the characteristics of this new vortex gripper, including pressure distribution on the upper surface of the workpiece, lifting force, supporting stiffness, and flowrate, a computational fluid dynamics study has been carried out. In the vortex cup, air swirling flow is a complex turbulent one; so Reynolds stress model (RSM) was used to describe internal air swirling flow. In addition, an experiment was carried out to study the characteristics of the vortex gripper. When compared with the experimental results, the reliability of numerical simulation results by RSM was verified. The vortex gripper with a diversion body could generate greater lifting force when compared with those designed by Xin et al. with the same air consumption. Therefore, the efficiency of the vortex gripper is improved.


2013 ◽  
Vol 634-638 ◽  
pp. 3774-3777
Author(s):  
Min Hua Zhang ◽  
Hong Mei Zheng ◽  
Cui Liu ◽  
Yin Hu Qu ◽  
Tao Liang ◽  
...  

the inner flow fields of twelve Hema-type ATY nozzles which have different structure and parameters are simulated by the Fluent software, which is based on the CFD (Computational Fluid Dynamics) theory.Then the simulation results are analyzed,through wich the best designed nozzle is determined.


2012 ◽  
Vol 516-517 ◽  
pp. 1133-1138 ◽  
Author(s):  
Yi Tang ◽  
Jing Xie ◽  
Jin Feng Wang ◽  
Chen Miao ◽  
Yi Zheng

The quantity of the cold store in our country has been rapidly rising since the 1990s, however, the flow field in the cold store is difficult to obtain accurately by experiments. With reference to the experiences in previous numerical simulations in this paper, CFD is used for analyzing two forms of return air in the cold store with the Finite Volume Methods and the SIMPLE Revised. As a result, Combining with the non-equilibrium wall function, it is found that taking the way of return air on both sides of the fan is more reasonable and the cooling consumption of the empty cold store can be saved before the products enter the cold store. Furthermore, the numerical simulation results can provide reference for choosing fans in the small cold store.


2013 ◽  
Vol 353-356 ◽  
pp. 2993-2996 ◽  
Author(s):  
Tao Tao Shui ◽  
Jing Liu ◽  
Fei Ma

In order to investigate natural cross-ventilation in buildings, computational fluid dynamics (CFD) with the DES model is applied. The aim of this paper is to investigate the influence of surrounding buildings on natural ventilation in target building under different separation distances. The simulation results indicate that surrounding buildings has a significant impact on airflow structure and airflow rate of the target building. The flow characteristics in target building is determined by the flow regime in street canyon.


2014 ◽  
Vol 1048 ◽  
pp. 575-578
Author(s):  
Mei Ling Li ◽  
Chong Wen Yu ◽  
Shan Shan Shang

Effects of the distance between guided needle and cone body on properties of MVS yarns were investigated by numerical simulation. 5 groups of the distance are designed (0.5mm, 1mm, 1.5mm, 2mm and 2.5mm). The 3D computational fluid dynamics models are established to conduct the numerical simulation of the airflow in the nozzle. Through analysis of the characteristics of air flow inside the different nozzles, such as pressure distribution and velocity vectors, the motion of drafted fibers and performances of yarns are discussed. Simulation results show that when the distance is 1.5mm, the airflow state within the nozzle is beneficial to form more open-ends and twist, and the yarn quality would be better.


2011 ◽  
Vol 99-100 ◽  
pp. 857-861
Author(s):  
Neng Jun Jiang ◽  
Ya Ling Peng ◽  
Fang Liang Wu

Computational Fluid Dynamics (CFD) was used to study the force direction and magnitude of 2D journal bearing and tapered gap, also the load of 3D journal bearing at different eccentric ratio was studied using numerical method. All numerical simulation results were compared with theoretical analysis result, theoretical solution result and other available data from reference. The comparisons show good match between numerical simulation results and others. This paper had validated the reliability and accuracy of CFD which could be used to study the lubrication and oil film status for journal bearing with the gap less than 0.2mm and provide a sold foundation for CFD to be used for optimal design for journal bearing.


Author(s):  
Z F Huang ◽  
Z X Liu

The evolutionary characteristics of flow for the positive displacement blower were identified and visually analysed by performing numerical simulation of unsteady compressible flow in an involute-type three-lobe positive discharge blower using computational fluid dynamics. The two exhaust rate curves obtained by the semi-empirical method and the simulation were compared, and the differences were analysed by showing pressure contours and velocity vectors at different moments in one working period. The simulation results showed the exhaust rate having two V-type fluctuations, whereas the semi-empirical method shows the exhaust rate having only one V-type fluctuation. These differences are due to pressure fluctuations and the existence of a vortex in the mixing zone.


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