THERMAL SCIENCE

International Scientific Journal

Thermal Science - Online First

External Links

online first only

Numerical analysis of temperature fields around the buried arctic gas pipeline in permafrost regions

ABSTRACT
Based on one planned arctic natural gas pipeline engineering which will cross continuous, discontinuous, sporadic and non-permafrost areas from north to south, with different pipeline temperatures set, a thermal model of the interaction between pipeline and permafrost is established to investigate the influence of pipelines on the freezing and thawing of frozen soil around pipeline and thermal stability of permafrost. The results show that different pipeline temperatures influence the permafrost table greatly. Especially in discontinuous permafrost areas the permafrost table is influenced in both positive temperature and negative temperature. The warm gas pipeline of 5ºC could decrease the value of permafrost table about 1 to 3 times pipe diameter and aggravate the degradation of permafrost around pipeline; -1ºC and -5ºC chilled gas pipeline can effectively improve the permafrost table and maintain the temperature stability of frozen soil , but the temperature of soils below pipeline of -5ºC decreases obviously, which may lead to frost heave hazards. In terms of thermal stability around pipeline, it is advised that transporting temperature of -1ºC is adopted in continuous permafrost area; in discontinuous permafrost area pipeline could operate above freezing in the summer months with the station discharge temperature trending the ambient air temperature, but the discharge temperature must be maintained as -1ºC throughout the winter months; in seasonal freezing soil area chilled pipeline may cause frost heave, therefore pipeline should run in positive temperature without extra temperature cooling control.
KEYWORDS
PAPER SUBMITTED: 2020-05-21
PAPER REVISED: 2020-07-02
PAPER ACCEPTED: 2020-07-10
PUBLISHED ONLINE: 2020-09-12
DOI REFERENCE: https://doi.org/10.2298/TSCI200521248L
REFERENCES
  1. Li, G.Y., et al., Frost hazards and mitigative measures following operation of Mohe-Daqing line of China-Russia crude oil pipeline, Rock and Soil Mechanics, 2015, 36(10), pp. 2963-2973
  2. Yu, W.B., et al., Geohazards and thermal regime analysis of oil pipeline along the Qinghai-Tibet Plateau Engineering Corridor, Natural Hazards, 2016, 83(1), pp. 193-209
  3. Luo, D.L., et al., Characteristics of Water‐Heat Exchanges and Inconsistent Surface Temperature Changes at an Elevational Permafrost Site on the Qinghai‐Tibet Plateau, Journal of Geophysical Research: Atmospheres, 2018, 123(18), pp. 10057-10075
  4. Wang, Y.P., et al., Investigation of the freeze-thaw states of foundation soils in permafrost areas along the China-Russia Crude Oil Pipeline (CRCOP) route using the ground penetrating radar, Cold Regions Science and Technology, 2016, 126, pp. 10-21
  5. He, R.X., Jin, H.J., Permafrost and cold-region environmental problems of the oil product pipeline from Golmud to Lhasa on the Qinghai-Tibet Plateau and their mitigation, Cold Regions Science and Technology, 2010,64(3), pp. 279-288
  6. Brewer, M.C., et al., The changes of design of the Alyeska pipeline and construction modes in permafrost areas, and their reasons and the philosophy behind it, Journal of Glaciology and Geocryology, 2006, 28 (6), pp. 809-817
  7. Jurca, T., et al., Thermal-hydraulics modeling for buried gas pipeline strain-based design, The 27th International Ocean and Polar Engineering Conference. International Society of Offshore and Polar Engineers, 2017
  8. Zhou, J., et al., Application of strain-based design for pipelines in permafrost areas, 2006 International Pipeline Conference. American Society of Mechanical Engineers Digital Collection, 2006, pp. 899-907
  9. Oswell, J.M., Pipelines in permafrost: geotechnical issues and lessons, Canadian Geotechnical Journal, 2011, 48(9), pp. 1412-1431
  10. Koui, K., et al., Frost heave predictions of buried chilled gas pipelines with the effect of permafrost, Cold Regions Science and Technology, 2008, 53(1), pp. 382-396
  11. Zhang, M.Y., et al., Numerical analysis for critical height of railway embankment in permafrost regions of Qinghai-Tibetan plateau. Cold Regions Science and Technology, 2005, 41(2), pp. 111-120