The inerting technology is a common means to prevent fires in goaf of coal mine, which adsorption capacity the key index measure effect. Therefore, this paper obtained spontaneous combustion (CSC) stage Qianyingzi mine through programmed heating experiments, and determined physical temperature (below 323.15 K) matching actual environment. oxidation characteristics samples with different degrees were further studied by experiment TG-DSC test. results indicate that activation energy follows...

The high temperature and toxic gases produced by burning belt in mine are a serious threat to the miners' safety. A full-scale fire experiment was conducted an exercise roadway, as basis for which physical model established. spatial temporal evolution of environmental parameters obtained U-shaped working face, effect wind speed on studied. It found that smoke concentration from large small downwind side transport face return airway. structure layer near is disorganized, related local turning...

The utilization of CO2 is extremely important to solve the environmental problems and coal spontaneous combustion in goaf. There are three kinds goaf: adsorption, diffusion, seepage. Since adsorption will consume goaf, optimization injection amount very critical. A self-developed experimental device was used determine capacity different particle sizes lignite samples at 30-60 °C 0.1-0.7 MPa. factors affecting by its thermal effect were studied. In system, characteristic curve not affected...

In mine ventilation networks, the reasonable airflow distribution is very important for production safety and economy. Three basic problems of natural, full-controlled semi-controlled splitting were reviewed in paper. Aiming at high difficulty problem, general nonlinear multi-objectives optimization mathematical model with constraints was established based on theory networks. A new algorithm, which combined improved differential evaluation critical path method (CPM) multivariable separate...

The mining technology of gob-side entry retaining without a coal pillar is gradually becoming mature and increasingly important technology. As it maintains the roadway near goaf, air leakage should be greater than U-type ventilation system in so prone to cause spontaneous combustion problems. CO2 an inert gas, usually used prevent extinguish fire. However, there lack research on characteristics safety for pillar. In this paper, indexes influencing factors were proposed pipelines, technical...

To investigate the dispersion process of underground toxic gas carbon monoxide (CO) into refuge chamber during a mine disaster and enhance survival rate trapped miners, simplified model an main roadway was constructed. The impact temperature pressurized air volume on CO has been examined through both analog experiments numerical simulations, reliability simulation results verified. indicate that top protective isolation door occurs when in is lower than gas. When higher, it tends to enter...

In order to master the temperature and dissipation law of porous media-CO2 system, distribution adsorption field in media during intermittent CO2 injection was studied by using self-developed device experimental platform diffusion seepage. The results show that high is isotropic. effect on mainly occurs self-heating stage coal, area moves towards gas port. migration rate highest first injection. cooling decreases with increase times. Combined logistic function relationship between capacity...

In the process of coupling disaster prevention and control gas coal spontaneous combustion in goaf, there is a great contradiction between drainage carbon dioxide inerting technology. The key performance indexes are put forward to solve disaster, such as air quantity intake airway (A), rate (B), injection (C), depth (D). Using numerical simulation method orthogonal test four factors three levels, we establish model no. 7436 working face Kongzhuang mine. combination relative membership degree...

Carbon dioxide is a common inert gas used for fire prevention and extinguishing fires in underground coalmines. However, the single pipeline carbon injection has characteristics of narrow inerting area, serious leakage field, poor control. To address these risks, we herein propose technique multisource building up an index system goafs by analysing parameters pipe, mining technique, physical qualities gas. In addition, mathematical multi-pipeline model built on basis diffusion with pipeline....

To study the law of influence an explosion venting door on gas characteristics and verify its effect fast sealing performance, a large-sized pipeline experimental system was used. The tests were carried out under conditions 5.5, 7.5, 9.5, 11.5% concentration. characteristic parameters measured by data acquisition system. laws change in flame-proof analyzed. results showed that pressure peak attenuated 42.25, 50.54, 53.27, 52.88% aforementioned four working conditions. As volume fraction...

Cracks in coal goaf provide air leakage pathways and therefore increase the likelihood of spontaneous combustion, thus strongly affecting safety mining operations. Herein, an inorganic thixotropic gel (ITG) was proposed for inhibiting combustion by blocking this leakage. The orthogonal experiments were designed to examine effects composition on gelation time rheological/thixotropic properties. three interval thixotropy test optimal-composition (4 wt% sodium bentonite, 3 laponite, 0.46...

Using HigH LeveL Roadway to ContRoL gas emission in a LongwaLLmining FaCe -nUmeRiCaL simULation stUdy with the increase of coal mining depth, content seams could also become larger and larger, which suddenly cause an inrush into longwall face. it is very dangerous for miners' safety underground.The u-shaped ventilation pattern face that underground mines currently use not enough deliver sufficient air quantities dilute gases faces, result concentration over required celling limit by...

Abstract Aiming at the problem of fire prevention and extinguishment in 7271 working face Yaoqiao Mine, carbon dioxide inerting method was used to establish influencing factors system, which combining injecting pipeline parameters, mining technical parameters gas physical parameters. Numerical simulation study influence different injection depth volume on distribution flow field goaf. The range is determined by hierarchical experiment; Taking comparative experiment between obtain optimal for...

As the monitoring data of air velocity sensor is inaccurate in mine underground roadway, index system and mathematic model optimal location established based on variable fuzzy theory. The objective functions are minimum amount locations, which can obtain quantity each roadway. And constraints obey balance equation circuit node. In order to improving accuracy reduce disturbance measurement calculating results, adjustment analysis redundant standard deviation filter method put forward. Then,...

Abstract In order to study the process of underground harmful gas CO dispersion into refuge chamber and improve survival rate trapped personnel, a simple model main roadway was built. The influence temperature pressure air volume on in has been studied by analog experiment numerical simulation, reliability simulation results is verified. A flexible isolation door for controlling gases designed, installation compared analyzed. show that when lower than gas, will invade from upper part...

The adsorption of gases released during coal oxidation have a significant impact on the accuracy CSC prediction. However, there are few research C2H4 and C2H6 by coal. Therefore, characteristics N2/CO2/C2H4/C2H6 spontaneous combustion bituminous were investigated programmed heating experiment molecular simulation. results showed that low-volatile exhibited higher capacity for CO2, N2, compared to high-volatile sequence both High-volatile was CO2 > C2H6. electrostatic potential oxygen...

In order to improve the local convergence of differential evolution algorithm, we puts forward greedy (GE) algorithm based on search strategy. According fitness value and selection probability, population a generation is classed best vectors, better vectors poor vectors. The retained in child population, replaced if newly generated vector its neighborhood than objective vector, regenerated until new not worse vector. Improving locally ability ensuring diversity GE increases obviously....