A solar compression refrigeration apparatus to cool permafrost embankment

Sun, Zhaohui; Liu, Jiankun; Hu, Tianliang; You, Tingting; Fang, Jianhong

doi:10.1016/j.applthermaleng.2023.120034

Cited by 12 publications

(1 citation statement)

References 40 publications

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“…Under the influence of both climate warming and engineering construction, the permafrost under the Qinghai-Tibet railway, Qinghai-Tibet highway was accelerated to degenerate and warm, and that caused engineering problems in return, such as embankment settlement, crack, differential deformation, which could affect the engineering service performance directly [9][10][11][12][13]. To protect the underlying permafrost, a series of active cooling subgrade structure have been proposed to adjust thermal state through heat conduction, convection and radiation by using single or comprehensive application of insulation board, block gravel layer, ventilation pipe, thermosyphon, sunshade，and these methods have been demonstrated improving the thermal stability of highway and railway embankments [14][15][16][17][18][19][20][21].…”

Section: Introductionmentioning

confidence: 99%

Heat transfer characteristics resembling thermal semiconductor of expressway embankment with ventilation and open-block layer in warm and high-altitude permafrost regions

Yuan,

Yu,

et al. 2024

Preprint

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Active cooling measures has been widely used to protect the underlying permafrost and maintain the embankment stability. Based on the measured data of high-grade highway experimental demonstration engineering in the Beiluhe area on the Qinghai-Tibet Plateau, the heat transfer process and ground temperature response have been analyzed to reveal the thermal control mechanism of the expressway embankment with ventilation and open block layer. (1) Heat was transferred through the block layer in both horizontal and vertical directions by different driving modes. In the horizontal direction, heat was transferred by forced convection under the driving of the local prevailing wind. In the vertical direction, heat was transferred upward by natural convection in the cold season and downward by heat conduction in the warm season under the driving of temperature gradient between the upper and lower boundaries of the block layer. (2) The expressway embankment structure showed the thermal semiconductor effect in both directions. The horizontal and vertical equivalent heat conductivity in the cold period was approximately 6.25 times and 3.5 times of that in the warm period. (3) The underlying frozen soil foundation was provided a net heat released state, and the total released heat was approximately 1.2 times of the total heat absorption. As the result, thick and wide cold permafrost layer (T<-1.0℃) was generated gradually, permafrost table increased and ground temperature decreased generally. This expressway embankment with ventilation duct and block layer contributed to protect the underlying permafrost layer and improve the stability of the frozen soil foundation in the warm and high-altitude permafrost regions.

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Section: Introductionmentioning

confidence: 99%

Heat transfer characteristics resembling thermal semiconductor of expressway embankment with ventilation and open-block layer in warm and high-altitude permafrost regions

Yuan,

Yu,

et al. 2024

Preprint

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Microscopic Thermo‐Mechanical Properties and Phase Transition of Bulk Ice‐Ih

Wei,

Niu,

Yao

et al. 2024

Num Anal Meth Geomechanics

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The ice–water phase transition of bulk ice could develop with varying temperatures and external loads, significantly affecting its mechanical properties. The coupling effect of temperature and shear loads on the thermo‐mechanical properties of bulk ice and its phase transition evolution is poorly understood, especially at the nanoscale. In this study, molecular dynamics (MD) simulation method was employed to investigate the thermo‐mechanical behaviours of bulk ice‐Ih system at the microscale under various temperatures (73–270 K) and shear paths, where its phase transition, elastic properties, structure deformation mechanism and structural anisotropy were discussed. The simulation results show that (1) the shear modulus, shear strength and ultimate shear strain of bulk ice‐Ih system could linearly decrease with rising temperature, aligning with previous studies. (2) Two types of failure modes from bulk ice‐Ih system were founded, such as solid–liquid phase co‐existence at 73–225 K and liquid phase at 250–270 K. (3) Ice melting into water was attributed to the fracture of hydrogen bond during shear process. (4) Compared to vertical shearing (XZ () and YZ ()) directions, the mechanical response along the horizontal shearing (XY (0001)) direction was most sensitive to temperature effect.

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Developments in Permafrost Science and Engineering in Response to Climate Warming in Circumpolar and High Mountain Regions, 2019–2024

Burn,

Bartsch,

Chakraborty

et al. 2024

Permafrost & Periglacial

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Research in geocryology is currently principally concerned with the effects of climate change on permafrost terrain. The motivations for most of the research are (1) quantification of the anticipated net emissions of CO2 and CH4 from warming and thaw of near‐surface permafrost and (2) mitigation of effects on infrastructure of such warming and thaw. Some of the effects, such as increases in ground temperature or active‐layer thickness, have been observed for several decades. Landforms that are sensitive to creep deformation are moving more quickly as a result, and Rock Glacier Velocity is now part of the Essential Climate Variable Permafrost of the Global Climate Observing System. Other effects, for example, the occurrence of physical disturbances associated with thawing permafrost, particularly the development of thaw slumps, have noticeably increased since 2010. Still, others, such as erosion of sedimentary permafrost coasts, have accelerated. Geochemical effects in groundwater from trace elements, including contaminants, and those that issue from the release of sediment particles during mass wasting have become evident since 2020. Net release of CO2 and CH4 from thawing permafrost is anticipated within two decades and, worldwide, may reach emissions that are equivalent to a large industrial economy. The most immediate local concerns are for waste disposal pits that were constructed on the premise that permafrost would be an effective and permanent containment medium. This assumption is no longer valid at many contaminated sites. The role of ground ice in conditioning responses to changes in the thermal or hydrological regimes of permafrost has re‐emphasized the importance of regional conditions, particularly landscape history, when applying research results to practical problems.

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A solar compression refrigeration apparatus to cool permafrost embankment

Cited by 12 publications

References 40 publications

Heat transfer characteristics resembling thermal semiconductor of expressway embankment with ventilation and open-block layer in warm and high-altitude permafrost regions

Heat transfer characteristics resembling thermal semiconductor of expressway embankment with ventilation and open-block layer in warm and high-altitude permafrost regions

Microscopic Thermo‐Mechanical Properties and Phase Transition of Bulk Ice‐Ih

Developments in Permafrost Science and Engineering in Response to Climate Warming in Circumpolar and High Mountain Regions, 2019–2024

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