Determination of the rock subsidence spacingin the well underground coal gasification

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R.O. Dychkovskyi, Dr. Sci. (Tech.), Professor, State Higher Educational Institution “National Mining University”, Head of the Department of Development & Research, Professor of the Underground Mining Department, Dnipropetrovsk, Ukraine.


Purpose. The determination of the dependence of the roof rocks subsidence spacing on the thickness of the artificial bilayer shell formed by the variation of temperature and pressure during changing the composition of the mixtures. It is necessary for creating the workspace of the gasogene. This space is created for unobstructed passing of gas flows.

Methodology. The analytical research was based on the elastic and elastic-plastic deformations that occur in changing the artificial shell parameters in the zone influenced by the gas generator temperature field. For the shell creation the necessary temperature is formed in the center of gasification; gas-vapour mixtures are fed to melt the rocks on contour of the gasifier. These shells have the changing properties in comparison with the natural rock massif. In addition, they allows predicting the spacing of the roof rocks subsidence. These parameters had been determined analytically using the well-known analytical equation of Clapeyron-Mendeleev and experimentally, using the special installation developed by the scientists of the National Mining University. To process the data and plot the summarizing dependencies we used the multiple regression method and applied universal Excel-2013 tables’ data processing system.

Findings. The multivariate calculations of the rock subsidence have been carried out as a stage of determination of the stressed state around the georeactor for the artificial shells of various thickness on the gasification contour. Their compliance was tested experimentally on the special test site. The scale coefficients allow receiving the real parameters of deformations for geological conditions in the form of the established deformation and destruction zones of rocks and formation of the necessary space, which is required for the blowing mixtures passage.

Originality. The dependences of the rock displacement along the gas generator contour on the thickness of artificial bilayer shell, which characterizes the development of deformations in rock mass around the gasogene. The formulas for calculation of the spacing of the rock subsidence depending on the thickness of artificial shells. It is neccesary for the selection of the method of rock preasure control and providing the worckspace of the gasogen.

Practical value. The mathematical mechanism for determination of the deformation characteristics of the rock massif was proposed. Its effectiveness has been proved experimentally on the special test site. The dependences make the base for the method of the subsidence spacing determination depending on the thickness of the bilayer artificial shell, which is aimed to provide the stability of gasification. 


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Kolokolov, О.V. (2000), Teoriya i practika termokhimicheskoy tekhnologii dobychi i pererabotki uglya [Theory and Practice of Thermochemical Technologies of Coal Extraction and Processing], Monograph, NMA of Ukraine, Dnipropetrovsk, Ukraine.


Date 2016-02-08 Filesize 880.87 KB Download 552

Tags: georeactorblowing mixtureroof rock subsidenceartificially created shellstress-strain state

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