Determining the efficiency of functioning of systems of temperature stabilization of soils with horizontal evaporator filled with different refrigerants

About the authors:

Alexey A. Ishkov, Leading Specialist, Department of Physico-Chemical Methods of Enhancing Oil Recovery, Branch of KogalymNIPIneft LLC, Lukoil-Engineering (Tyumen); IshkovAA@tmn.lukoil.com

Anatoly A. Gubarkov, Cand. Sci. (Tech.), Leading Researcher, Subarctic Research and Training Ground of the Tyumen Scientific Center of the Siberian Branch of the Russian Academy of Sciences, Industrial University of Tyumen; agubarkov@rambler.ru

Gennady V. Anikin, Cand. Sci. (Phys.-Math.), Leading Researcher, Earth Cryosphere Institute, Tyumen Scientific Centre of the Siberian Branch of the Russian Academy of Sciences; anikin@ikz.ru

Abstract:

The construction of buildings and structures in the zones of distribution of frozen soils follows the principle I. The bearing capacity of frozen soils significantly depends on their value of negative temperature. When thawed, such soils shrink, which negatively affects the objects built on them. To prevent this, temperature stabilization systems for frozen soils are used.
Simultaneous accounting of the thermal effect on the frozen soil of an engineering object, as well as the temperature stabilization system of soils, is a difficult task, the accuracy of determining the strength characteristics of the soil will depend on the correctness of its solution. This paper presents calculations of the temperature fields of frozen soils with simultaneous exposure to an object with intense heat (RVS with hot oil) and soil temperature stabilization system of the horizontal natural-acting tubular system (GET) type. The calculations follow the previously developed mathematical model of the temperature stabilization system with a horizontal evaporator. The authors consider the efficiency of the operation of the GET system charged with different refrigerants (ammonia and carbon dioxide) for different geocryological subzones of Western Siberia. Particular attention should be paid to the fact that the soil was initially at a close to positive temperature (−0,1 °C), but after calculating for 10 years, the entire soil mass around the evaporation part of the temperature stabilization system froze because of the soil temperature stabilization system. Systems charged with carbon dioxide showed better work efficiency. This is due to two factors: a lower value of the lower critical heat load, which gives more working days per year relative to the system charged with ammonia; and the evaporative part of the system on carbon dioxide, which has the average temperature 1 °C lower than ammonia systems. The results show that carbon dioxide as the heat carrier for the GET system is the most effective.

References:

1. Anikin G. V., 2009. Simulating the Operation of Cooling Systems with Horizontal Tubes. Deposited at VINITI 30 October 2009, No. 674-V2009. Moscow: IKZ. [In Russian]

2. Anikin G. V., Spasennikova K. A. 2012. “Computer modelling of the ground cooling system under the oil-tank”. Earth’s Cryosphere, vol. 16, no 2, pp. 60-64. [In Russian]

3. Anikin G. V., Plotnikov S. N., Spasennikova K. A. 2011. “Computer simulation of heat-mass exchange in the systems of horizontal ground cooling”. Earth’s Cryosphere, vol. 15, no 1, pp. 33-39. [In Russian]

4. Anikin G. V., Spasennikova K. A. 2014. “About choice of refrigerating fluid for the seasonal cooling devices of ‘GET’ type”. Earth’s Cryosphere, vol. 18, no 2, pp. 31-33. [In Russian]

5. Ershov E. D. (ed.). 1989. USSR Geocryology. Middle Siberia. Мoscow: Nedra. [In Russian]

6. Dolgikh G. M. et al. 2011. “Research of soil temperature stabilization systems at a pilot industrial training ground”. Proceedings of the International Research Conference on Permafrost Engineering on the 20^th Anniversary of the Foundation of NPO Fundamentstroyarkos LLC, pp. 36-42. Tyumen: City Press. [In Russian]

7. Dolgikh G. M., Rilo I. P., Zheludkova K. A. 2014. “New prospects for the northern construction of residential and office buildings using carbon dioxide systems for temperature stabilization of soils”. In: Akhmetova V. D. (ed.). Systems of Temperature Stabilization of Base Soils in the Permafrost Zone. Actual Issues of Research, Calculations, Design, Production, Construction, Field Supervision and Monitoring, pp. 208-215. Novosibirsk: Geo. [In Russian]

8. Dolgikh G. M., Dolgikh D. G., Okunev S. N. 2004. “Technical solutions for the freezing of base soils used by the NGO Fundamentstroyarkos”. Proceedings of the International Conference “Cryosphere of Oil and Gas Provinces”, p. 56. Tyumen. [In Russian]

9. Melnikov V. P. et al. 2014. “Engineering solutions for building on permafrost in perspective energy-efficient enhancement”. Earth’s Cryosphere, vol. 18, no 3, pp. 82-89. [In Russian]

10. Melnikov V. P., Drozdov D. S., Malkova G. V. 2009. “Climatic and cryogenic factors in the arrangement of the northern territories”. News of Higher Educational Institutions. Geology and Exploration, vol. 15, no 6, pp. 75-83. [In Russian]

11. Melnikov V. P. et al. 2017. “Maximum and minimum critical thermal loads constraining the operation of thermosyphons with horizontal evaporator tubes (HET)”. Earth’s Cryosphere, vol. 21, no 3, pp. 41-48. [In Russian]

12. Bykov A. V. (ed.). 1985. Various Applications of Cold. Moscow: Agropromizdat. [In Russian]

13. RSFSR State Committee for Construction. 1987. Engineering Surveys for Construction. Making a Forecast of Changes in the Temperature Regime of Permafrost by Numerical Methods. RSN 67-87. Moscow: RSFSR State Committee for Construction. [In Russian]

14. Samarsky A. A., Vabishchevich P. N. 2003. Computational Heat Transfer. Moscow: Editorial. [In Russian]

15. Feklistov V. N. et al. 2008. “The study of the ‘GET’ cooling system type for thermal stabilization of soil bases”. Proceedings of the International Conference “Cryogenic Resources of the Polar and Mountainous Regions. State and Prospects of Permafrost Engineering”, vol. 2, pp. 165-168. Tyumen. [In Russian]