To investigate the effect of soil cover thickness on the combustion and explosion behavior of buried liquefied petroleum gas leakage, an experimental system for underground leakage-induced combustion and explosion was established. Four soil cover thicknesses of 80 mm, 120 mm, 160 mm and 200 mm were set to record flame propagation and temperature field evolution. The results show that the flame undergoes four stages: initial ignition, rapid expansion, full combustion and decay extinction. Under 80 mm soil cover, the flame exhibits upper-lower separation, with the lowest peak height (873.9 mm). At 160 mm, the peak flame height reaches the maximum (1408.1 mm) and occurs earliest. At 200 mm, the premixing is most sufficient, giving the highest peak temperature (1406.5 °C), but the peak appears latest and decays most slowly. Soil cover thickness significantly influences flame morphology, height, temperature and decay characteristics. These findings provide a theoretical basis for the safety design and risk prevention of buried liquefied petroleum gas systems.
- Open Access
- Article
Research on the Evolution Characteristics of Soil-Covered Liquefied Petroleum Gas Leakage and Explosions
Author Information
Received: 14 Apr 2026 | Revised: 26 Apr 2026 | Accepted: 29 Apr 2026 | Published: 07 May 2026
Abstract
Keywords
liquefied petroleum gas | buried leakage | soil cover thickness | flame propagation | temperature field
References
- 1.
Yan, Y.T.; Zhang, H.R.; Li, J.M.; et al. Simulations on the Diffusion of Natural Gas in the Soil for Medium-Pressure Gas Pipeline Leak. J. Saf. Sci. Technol. 2014, 10, 5–10.
- 2.
Deborah, H.A.; Blanchetière, G.; McCollum, D.; et al. Consequences of a 12 mm Diameter High Pressure Gas Release on a Buried Pipeline. Experimental Setup and Results. J. Loss Prev. Proc. Ind. 2018, 54, 183–189.
- 3.
Zhu, J.L.; Pan, J.; Zhang, Y.X.; et al. Leakage and Diffusion Behavior of a Buried Pipeline of Hydrogen‑Blended Natural Gas. Int. J. Hydrogen Energy 2023, 48, 11592–11610.
- 4.
Yan, Y.T.; Dong, X.Q.; Li, J.M. Experimental Study of Methane Diffusion in Soil for an Underground Gas Pipe Leak. J. Nat. Gas Sci. Eng. 2015, 27, 82–89.
- 5.
Latifi, M.; Parvaneh, R.; Naeeni, S.T.O. Investigating the Influence of Surrounding Soil Properties on Leakage Discharge from Cracks in Polyethylene Pipes. Eng. Fail. Anal. 2022, 141, 106676.
- 6.
Hibi, Y.; Kanou, Y.; Ohira, Y. Estimation of Mechanical Dispersion and Dispersivity in a Soil-Gas System by Column Experiments and the Dusty Gas Model. J. Contam. Hydrol. 2012, 131, 39–53.
- 7.
Zhang, W.K.; Zhao, G.H. Leakage and Diffusion Characteristics of Underground Hydrogen Pipeline. Petrol. 2024, 10, 319–325.
- 8.
Peng, S.Y.; Zhang, H.W.; Chai, C.; et al. Effects of Soil Properties on the Diffusion of Hydrogen-Blended Natural Gas from an Underground Pipe. Fluid Dyn. Mater. Process. 2025, 21, 1099–1112.
- 9.
Liu, Y.L.; Zheng, J.Y.; Xu, P.; et al. Numerical Simulation on the Diffusion of Hydrogen Due to High Pressured Storage Tanks Failure. J. Loss Prev. Proc. Ind. 2009, 22, 265–270.
- 10.
Yuan, Y.P.; Cui, W.Y.; Tong, L. Prediction and Sensitivity Analysis of Hydrogen Leak Diffusion Using CFD and Data-Driven Modeling under Variable Leak and Wind Conditions. Int. J. Hydrogen Energy 2026, 202, 153056.
- 11.
Wagih, A.; Oz, F.E.; Melentiev, R.; et al. Advancing Safety of Hydrogen Polymeric Tanks: A Review of Permeation Mitigation, Leak Detection, and Smart Monitoring. Int. J. Hydrogen Energy 2025, 176, 151334.
- 12.
Wang, X.M.; Hou, T.L.; Gao, W.X.; et al. Experimental Study on the Diffusion Process of Natural Gas from Buried Pipelines to Underground Confined Spaces. Nat. Gas Ind. B 2024, 11, 603–615.
- 13.
Wang, X.M.; Tan, Y.F.; Zhang, T.T.; et al. Numerical Study on the Diffusion Process of Pinhole Leakage of Natural Gas from Underground Pipelines to the Soil. J. Nat. Gas Sci. Eng. 2021, 87, 103792.
- 14.
Lyu, S.; Yang, X.B.; Ma, X.Y.; et al. CFD Modeling of Leakage and Dispersion Characteristics of Buried Natural Gas Pipelines—Part 1: Numerical Simulation. Int. Commun. Heat Mass Transfer 2026, 172, 110351.
- 15.
Ebrahimi-Moghadam, A.; Farzaneh-Gord, M.; Deymi-Dashtebayaz, M. Correlations for Estimating Natural Gas Leakage from Above-Ground and Buried Urban Distribution Pipelines. J. Nat. Gas Sci. Eng. 2016, 34, 185–196.
- 16.
Ebrahimi-Moghadam, A.; Farzaneh-Gord, M.; Arabkoohsar, A.; et al. CFD Analysis of Natural Gas Emission from Damaged Pipelines: Correlation Development for Leakage Estimation. J. Clean. Prod. 2018, 199, 257–271.
- 17.
Liu, C.W.; Liao, Y.H.; Liang, J.; et al. Quantifying Methane Release and Dispersion Estimations for Buried Natural Gas Pipeline Leakages. Process Saf. Environ. Prot. 2021, 146, 552–563.
- 18.
Wang, D.; Liu, P.; Hua, C.G.; et al. Research on Natural Gas Leakage Diffusion of Urban Underground Pipeline and Its Explosion Hazard. KSCE J. Civ. Eng. 2023, 27, 590–603.
- 19.
Yang, Z.; Li, X.H.; Lai, J.B. Analysis on the Diffusion Hazards of Dynamic Leakage of Gas Pipeline. Reliab. Eng. Syst. Saf. 2007, 92, 47–53.
- 20.
Hu, Q.F.; Zhang, Z.Y.; Su, Z.; et al. Investigation and Numerical Simulation of a Severe Leakage in an Ultra-Deep Buried Gas Pipeline: A Case Study. Constr. Build. Mater. 2025, 491, 142745.
- 21.
Zhang, G.W.; An, Z.Y.; Liu, X.P.; et al. Consequence Analysis of Accidental Gas Leak from Storage Tank Group Using LES Method. J. Loss Prev. Proc. Ind. 2025, 94, 105529.
- 22.
Ikwan, F.; Sanders, D.; Hassan, M. Safety Evaluation of Leak in a Storage Tank Using Fault Tree Analysis and Risk Matrix Analysis. J. Loss Prev. Proc. Ind. 2021, 73, 104597.
- 23.
Yu, J.X.; Ding, H.Y.; Yu, Y.; et al. Risk Assessment of Liquefied Natural Gas Storage Tank Leakage Using Failure Mode and Effects Analysis with Fermatean Fuzzy Sets and CoCoSo Method. Appl. Soft Comput. 2024, 154, 111334.
- 24.
Wu, Y.J.; Yang, G.; Sun, J.G.; et al. Digital Twin Modeling and Leak Diagnosis of Temperature and Stress Fields in LNG Storage Tanks. Measurement 2024, 228, 114374.
- 25.
Xie, Y.S.; Wang, T.; Lv, L.H.; et al. Full-Scale Experiment of Diffusion Behaviors of City Pipeline Gas in Soils. Nat. Gas Ind. 2015, 35, 106–113.
- 26.
Chen, L.D.; Roquemore, W.W.M.; Goss, L.P.; et al. Vorticity Generation in Jet Diffusion Flames. Combust. Sci. Technol. 1991, 77, 41–57.
- 27.
Hu, L.; Lu, K.; Delichatsios, M.; et al. An Experimental Investigation and Statistical Characterization of Intermittent Flame Ejecting Behavior of Enclosure Fires with an Opening. Combust. Flame 2012, 159, 1178–1184.
- 28.
Fang, J.; Wang, J.W.; Guan, J.F.; et al. Momentum- and Buoyancy-Driven Laminar Methane Diffusion Flame Shapes and Radiation Characteristics at Sub-Atmospheric Pressures. Fuel 2016, 163, 295–303.
- 29.
Goss, L.P.; Katta, V.R.; Roquemore, W.M. Simulation of Vortical Structures in a Jet Diffusion Flame. Int. J. Numer. Methods Heat Fluid Flow 1994, 4, 413–424.
- 30.
Cetegen, B.M.; Kasper, K.D. Experiments on the Oscillatory Behavior of Buoyant Plumes of Helium and Helium-Air Mixtures. Phys. Fluids 1996, 8, 2974–2984.
- 31.
Yan, M.Q.; Xu, P.; Li, J.; et al. A Buried Gas Pipeline Leakage Model. J. Pipeline Syst. Eng. Pract. 2024, 15, 04024046.
- 32.
Zhang, R.H.; Chen, G.H.; Huang, S. A Multiphase Mixture Flow Model and Numerical Simulation for the Release of LPG Underground Storage Tank in Porous Environment. In Proceedings of the ASME 2007 Pressure Vessels and Piping Conference, San Antonio, TX, USA, 22–26 July 2007; Volume 42827, pp. 543–550.
- 33.
Liu, S.X.; Hu, L.H. An Experimental Study on Flame Envelope Morphologic Characteristics of Downward‑Orientated Buoyant Turbulent Jet Fires. Proc. Combust. Inst. 2019, 37, 3935–3942.
- 34.
Zhou, G.; Kong, Y.; Bing, Y.X.; et al. Characterization of Explosion Venting Flame-Shock Wave Coupling Dynamics of LPG/DME Blended Gas under the Influence of Highly Reactive DME. Combust. Flame 2025, 274, 113980.
- 35.
Coriton, B.; Frank, J.H.; Gomez, A. Effects of Strain Rate, Turbulence, Reactant Stoichiometry and Heat Losses on the Interaction of Turbulent Premixed Flames with Stoichiometric Counterflowing Combustion Products. Combust. Flame 2013, 160, 2442–2456.
- 36.
Kang, Y.; Cheng, Z.Y. Study on Explosion Characteristics and Consequences of Buried Gas Pipelines. Process Saf. Prog. 2025, 44, 499–513.
- 37.
Wang, K.; Tao, C.F.; Liu, Q.; et al. An Experimental Investigation of Flame Height and Air Entrainment Rate of Double Jet Fires. Exp. Heat Transfer 2018, 31, 22–31.
- 38.
Bonnaud, C.; Cluzel, V.; Corcoles, P.; et al. Experimental Study and Modelling of the Consequences of Small Leaks on Buried Transmission Gas Pipeline. J. Loss Prev. Proc. Ind. 2018, 55, 303–312.
- 39.
Wan, H.X.; Ji, J.; Li, K.Y.; et al. Effect of Air Entrainment on the Height of Buoyant Turbulent Diffusion Flames for Two Fires in Open Space. Proc. Combust. Inst. 2017, 36, 3003–3010.
- 40.
Dahlgren, R.M.T.; Clifford, H.T. The Monocotyledons: A Comparative Study; Academic Press: London, UK/New York, NY, USA, 1982.
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