Simulation experiment method of flow field in heterogeneous goaf in fully mechanized caving face

Abstract

The invention relates to a fully mechanized caving face inhomogeneous goaf flow field simulation experiment method. According to the technical schemes of the invention, the method includes the following steps that: a simulation experimental device is installed; and B, mining is simulated. The simulation of the mining further includes the following steps that: a tackle is moved through a jack, so that a simulated goaf is formed; the top similar rock strata of the simulated goaf start to fall, a heating pipe below a falling area is turned on, and temperature is increased to 200 to 300 DEG C; thereal-time temperature of the goaf is monitored through a thermocouple; gas extraction and sampling are performed on the falling area through a gas extraction pipe at intervals of certain time; collected gases are numbered and marked with notes; the collected gases are conveyed to a laboratory, and the components of the gases are checked through a using gas chromatograph; and the acquisition of the temperature and gas experimental data of the goaf is completed. According to the method of the invention, the similar coal and rock strata are laid on a box body and the tackle; the tackle is pulledand pushed, so that a mining process can be simulated; and after an upper coal covering rock stratum is not supported by the tackle any more, the coal covering rock stratum is deformed and damaged, and even falls due to the weight of the coal covering rock stratum, and the whole process is a natural falling process, and the similarity of the formed heterogeneous goaf and a site is greatly improved .

Description

technical field [0001] The invention relates to a goaf flow field simulation experiment method, in particular to a fully mechanized caving face heterogeneous goaf flow field simulation experiment method. Background technique [0002] my country is a country where coal spontaneous combustion is relatively serious. The annual resource and environmental losses caused by coal spontaneous combustion are incalculable. Due to reasons such as low recovery rate and slow advancement speed, coal spontaneous combustion is more likely to occur in fully mechanized coal mining face. According to statistics, more than 95% of coal spontaneous combustion occurs in goafs where personnel cannot directly see or reach, so it is difficult to accurately obtain the physical and chemical parameters of coal spontaneous combustion fire source, resulting in poor fire extinguishing effect. Therefore, it is necessary to establish certain technical methods for research The distribution and spread of coal s...

AI Technical Summary

Problems solved by technology

At present, the existing physical models of the goaf are mostly filled with gravel, crushed coal and other artificial materials to form the goaf. After the model is loaded with overlying pressure, the research results cannot be well matched with the actual field

[0004] In order to form a goaf physical model with a high degree of similarity with the field, the inventor applied for and authorized the patent number ZL201410453668.1 in 2014 for the "mechanized caving / mining Longwall working face goaf flow field simulation test device and method", after later research, it was found that the device has the following problems: ① The similarity with the field is not high

For example, the overlying coal strata will drop together with the slider during the descent of the hydraulic lifting rod, making it difficult to form a heterogeneous goaf with a high degree of similarity; the width of the slider is set uniformly so that the progress of each coal mining is equal; on-site fully mechanized caving The ventilation height of the coal mining face is the height of the support, and the ventilation height of the device is the height of the support and coal discharge; there is no baffle in the direction of the goaf of the working face in the device, and the overlying coal stratum falls behind and blocks the working face

② There are many hydraulic lifting rods, the management is complicated, easy to be damaged, and difficult to replace

For example, the length of this device is 3800mm, and the length of the protective coal wall at both ends is 400mm. According to each simulated coal mining of 50mm, 68 rows of hydraulic lifting rods are required, and if there are two hydraulic lifting rods under each slider, 136 rows are required. Each hydraulic lifting rod needs oil pipes or air pipes, which makes management complicated; hydraulic rods have defective rate problems, and one of them is damaged, which will affect the normal progress of the experiment; considering the safety and size of the lower part, hydraulic lifting rods, thermocouples and other electronic Difficult to replace if damaged

③The control of the device is complex and costly, and it is difficult to realize under the existing technical conditions

For example, when the 68 rows of sliders are descending, two hydraulic lifting rods need to be lowered synchronously and stably, which greatly increases the cost of the device; when there is inclination and debris between the sliders, the friction between the sliders will be increased, thereby preventing the sliders from descending to the designated position; the slider is made of metal, and the device does not consider the heat dissipation of the lower part of the slider; during the descent of the slider, it will disturb the stope flow field and affect the accuracy of the measurement data; The block becomes narrower, which makes the hydraulic lifting rod become more, and it is not easy to buy a suitable hydraulic lifting rod in the market

Images