Temperature and Pressure Dependences of the Effective Thermal Conductivity of Granites

Abstract

An analysis is performed of the experimental temperature and pressure dependences of thermal conductivity for different granite samples, obtained using the absolute stationary approach at 273-523 K and 0.1-400 MPa. The power mode of the temperature dependence of thermal conductivity at a fixed pressure with pressure-dependent coefficients is established.

Effect of Pressure on the Temperature Dependence of the Thermal Conductivity of Arsenic Chalcogenide with Different Ordering

“…As we showed in [1][2][3], the temperature dependence of effective thermal conductivity λ of most composite materials at fixed pressures is governed by the power law (1) The wave nature of heat transfer in crystals is reflected in temperature dependence (1) with coefficient n ≅ 1 [4,5]. We also arrive at (1) under the activation-type mechanism of heat transfer in amorphous bodies, but with coefficient n ≅ 0.5. There is no ordering of atoms in the disordered crystalline state, so the masses of atoms and their force constants change randomly from point to point.…”

Effect of Structural Ordering, Temperature, and Pressure on Processes of Heat Transfer in Minerals and Alloys

“…Numerous data of our own [8][9][10] and from the literature [12][13][14][15][16][17][18][19][20][21] show that n = −1 for ordered minerals and alloys; n = −0.5 for partially ordered minerals and alloys; n = 0 when the degree of disorder in minerals and alloys is ε = 36.4% [18]; and n = 0.5 for when the structure of minerals and rocks is amorphous (with no long-range translational bonds between atoms). The temperature dependence of the efficient thermal conductivity of minerals and rocks thus lies within the narrow domain of to and provides an estimate of their degree of disorder ε.…”

“…In amorphous and glassy minerals and alloys with no long-range translational bonds between atoms, efficient thermal conductivity depends weakly on temperature. A review of the literature data [6][7][8][9][10][11] shows † Deceased.…”

“…Our recent works were dedicated to revealing the relationship between exponent n and other characteristics of a composite compound [8][9][10]. This work presents experimental results from determining the efficient thermal conductivity of sandstone samples (Aktash deposit, Republic of Dagestan: depth, 2970 m; density, 2.7 × 10 3 kg m −3 ; open porosity k = 5%) in the 273-523 K range of temperatures at a hydrostatic pressure of 0.1-400 MPa (measured using absolutely stationary flat plates [10]).…”

Heating and cooling of water injected into the well

“…For example, the specific volumetric heat capacity of water for low temperatures is 4.2 MJ/m 3 K, while for hot water it is 4.5 MJ/m  K. The measured parameters of rocks required for calculations can be found in [6]. The variation limits and PT-behavior of rocks thermal conductivity were discussed in [7,8].…”