Equivalent thermal conductivity coefficient measurement system and calculation method for fractured rock mass unit structure

Abstract

The invention discloses an equivalent thermal conductivity coefficient measurement system and calculation method for a fractured rock mass unit structure. A single fracture seepage plate is arranged in a heating thermal insulation box body, an extracted fractured rock mass unit structure is simulated as matrix rock blocks with different porosity and single fractures, the equivalent thermal conductivity coefficient measurement system for a fractured rock mass unit is designed through the fact that the periphery of the single fracture seepage plate in the heating thermal insulation box body is filled with the matrix rock blocks simulated by rock like materials, and then the single fractures at different angles can be simulated by adjusting the included angle between the single fracture seepage plate and the heat flow direction; and after changing the test conditions, equivalent thermal conductivity coefficients of the matrix rocks with the different porosity, the single fractures at thedifferent angles, different fracture widths, fluid types, fluid flow in different fractures or pressure gradients can be analyzed. According to the equivalent thermal conductivity coefficient measurement system and calculation method for the fractured rock mass unit structure, the equivalent thermal conductivity coefficient of the fractured rock mass unit under the porosity matrix blocks and single fracture water seepage conditions can be studied, and a foundation for study of moisture and heat migration of a whole fractured rock mass is laid.

Description

technical field [0001] The invention relates to a test device and a calculation method, in particular to an equivalent thermal conductivity test system and a calculation method of a fractured rock mass unit structure. Background technique [0002] As the mines in the eastern and part of the central part of my country enter deep mining, facing the special mining conditions of high seepage water pressure, high ground stress, and high ground temperature, mine heat damage is becoming more and more serious. The reason for the high temperature in the deep rock mass is not only the rise of the geothermal gradient, but also the impact of mining, such as figure 1 As shown, high geostress leads to the development of fractures in rock mass, and high seepage water pressure makes mine water migrate along the fracture network, and this process is accompanied by heat transfer. The heat transfer modes of fractured rock mass mainly include: ① heat conduction of matrix rock blocks; ② heat co...

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Problems solved by technology

The heat transfer modes of fractured rock mass mainly include: ① heat conduction of matrix rock blocks; ② heat conduction and heat convection of fluid in fissures, because heat convection of fluid in fissures involves the determination of convective heat transfer coefficient of water-rock interface, convective heat transfer Coefficient h is a dynamic value related to flow velocity v, gap width b, geometric characteristics of water-rock interface, thermophysical properties of water-rock, etc. It is a complex variable. Currently, there is no suitable empirical formula or definite theory for the value of h , resulting in more complex research on seepage-heat transfer problems in fractured rock mass

In order to simplify the problem, it can be considered to extract the basic rock unit containing a single fracture from the fractured rock mass, and study the equivalent thermal conductivity of the fractured unit. However, there is no good method to accurately study the equivalent thermal conductivity. Provide a theoretical basis for the study of water-heat migration in fractured rock mass

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