Ground Heat Transfer from Civil Infrastructure with Seasonal Freezing and Thawing

2012 ◽  
pp. 233-266
Author(s):  
X. Duan ◽  
G. F. Naterer
Keyword(s):  
Heat Transfer ◽  
Civil Infrastructure ◽  
Freezing And Thawing ◽  
Seasonal Freezing

scholarly journals Sensitivity of the results of modeling of seasonal ground freezing to selection of parameterization of the snow cover thermal conductivity

2019 ◽  
Vol 59 (1) ◽  
pp. 67-80 ◽  
Author(s):  
S. P. Pozdniakov ◽  
S. O. Grinevskyi ◽  
E. A. Dedulina ◽  
E. S. Koreko
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Snow Cover ◽  
Soil Profile ◽  
Average Density ◽  
Temperature Correction ◽  
Freezing And Thawing ◽  
Coupled Models ◽  
Seasonal Freezing ◽  
Effective Medium Model

The relationship between the results of calculations of the dynamics of the temperature regime of the in freezing and thawing soil profile with the heating effect of the snow cover is considered. To analyze this connection, two coupled models are used: the model of formation and degradation of snow cover in winter and the model of heat transfer and soil moisture transport in underlying vadoze zone profile. Parametrization of the influence of the snow cover, which at each calculated moment of time has the current average density and depth, on the dynamics of the temperatures of the soil profile is due to the use of its specific thermal resistance, which depends on its current depth and the thermal conductivity coefficient. The coefficient of thermal conductivity of the snow cover is related with its density using six different published empirical relationships. Modeling of heat transfer in freezing and thawing soil is carried out on the example of the field site for monitoring the thermal regime located on the territory of the Zvenigorod Biological Station of Moscow State University. It is shown that the well-known relationships give similar curves for the dynamics of the depth of seasonal freezing, including the degradation of the seasonal freezing layer in the spring period, with the same dynamics of the snow cover. However, the maximum penetration depth of the zero isotherm differs significantly for different snow conductivity-snow density relationships. The tested six relationships were divided into three groups. Minimal freezing is provided by the Sturm model and the effective medium model. The average and rather poorly differentiating freezing from each other is given by the Pavlov, Osokin et al. and Jordan relationships. The greatest value of the freezing depth is obtained with using Pavlov’s relationship with a temperature correction. 

scholarly journals Modeling of Coupled Water and Heat Transfer in Freezing and Thawing Soils, Inner Mongolia

Water ◽  
2016 ◽  
Vol 8 (10) ◽  
pp. 424 ◽  
Author(s):  
Ying Zhao ◽  
Bingcheng Si ◽  
Hailong He ◽  
Jinghui Xu ◽  
Stephan Peth ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Inner Mongolia ◽  
Freezing And Thawing

scholarly journals A finite volume-based model for the hydrothermal behavior of soil under freeze–thaw cycles

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0252680
Author(s):  
Tianfei Hu ◽  
Tengfei Wang
Keyword(s):  
Heat Transfer ◽  
Finite Volume ◽  
Fluid Transport ◽  
Numerical Solutions ◽  
Dynamic Equilibrium ◽  
Phase Changes ◽  
Freezing And Thawing ◽  
Water Ice ◽  
Freeze Thaw ◽  
Physics Model

Freeze–thaw cycles in soil are driven by water migration, phase transitions, and heat transfer, which themselves are closely coupled variables in the natural environment. To simulate this complex periglacial process at different time and length scales, a multi-physics model was established by solving sets of equations describing fluid flow and heat transfer, and a dynamic equilibrium equation for phase changes in moisture. This model considers the effects of water–ice phase changes on the hydraulic and thermal properties of soil and the effect of latent heat during phase transition. These equations were then discretized by using the finite volume method and solved using iteration. The open-source software OpenFOAM was used to generate computational code for simulation of coupled heat and fluid transport during freezing and thawing of soil. A set of laboratory freezing tests considering two thermal boundary conditions were carried out, of which the results were obtained to verify the proposed model. In general, the numerical solutions agree well with the measured data. A railway embankment problem, incorporating soil hydrothermal behavior in response to seasonal variations in surface temperature, was finally solved with the finite volume-based approach, indicating the algorithm’s robustness and flexibility.

Thermal Protection of a Ground Layer With Phase Change Materials

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
X. Duan ◽  
G. F. Naterer
Keyword(s):  
Surface Temperature ◽  
Phase Change ◽  
Phase Change Materials ◽  
Thermal Protection ◽  
Ground Surface ◽  
Thermal Barrier ◽  
Freezing And Thawing ◽  
Temperature Variations ◽  
Seasonal Freezing ◽  
Freezing And Thawing Cycles

Conventional ground surface insulation can be used to protect power line foundations in permafrost regions from the adverse effects of seasonal freezing and thawing cycles. But previous studies have shown ineffective thermal protection against the receding permafrost with conventional insulation. In this paper, an alternative thermal protection method (phase change materials (PCMs)) is analyzed and studied experimentally. Seasonal ground temperature variations are estimated by an analytical conduction model, with a sinusoidal ground surface temperature variation. A compensation function is introduced to predict temperature variations in the foundation, when the ground surface reaches a certain temperature profile. Measured data are acquired from an experimental test cell to simulate the tower foundation. With thermal energy storage in the PCM layer, the surface temperature of the soil was modified, leading to changes in temperature in the foundation. Measured temperature data show that the PCM thermal barrier effectively reduces the temperature variation amplitude in the foundation, thereby alleviating the seasonal freezing and thawing cycles. Different thermal effects of the PCM thermal barrier were obtained under different air temperature conditions. These are analyzed via melting degree hours and freezing degree hours, compared with a critical number of degree hours.

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