Open Access

ARTICLE

CFD Investigation of Diffusion Law and Harmful Boundary of Buried Natural Gas Pipeline in the Mountainous Environment

Liqiong Chen¹, Kui Zhao¹, Kai Zhang^1,*, Duo Xv¹, Hongxvan Hu², Guoguang Ma¹, Wenwen Zhan³

1 School of Petroleum Engineering, Southwest Petroleum University, Chengdu, 610000, China
2 National Pipe Network Group Southwest Pipeline Co., Ltd., Chengdu, 610000, China
3 National Pipeline Research Center Conveyance Pipe Institute, Baoji Petroleum Steel Pipe Co., Ltd., Baoji, 721000, China

* Corresponding Author: Kai Zhang. Email:

(This article belongs to the Special Issue: Integrated Geology-Engineering Simulation and Optimizationfor Unconventional Oil and Gas Reservoirs)

Energy Engineering 2024, 121(8), 2143-2165. https://doi.org/10.32604/ee.2024.049362

Received 04 January 2024; Accepted 29 March 2024; Issue published 19 July 2024

Abstract

The leakage gas from a buried natural gas pipelines has the great potential to cause economic losses and environmental pollution owing to the complexity of the mountainous environment. In this study, computational fluid dynamics (CFD) method was applied to investigate the diffusion law and hazard range of buried natural gas pipeline leakage in mountainous environment. Based on cloud chart, concentration at the monitoring site and hazard range of lower explosion limit (LEL) and upper explosion limit (UEL), the influences of leakage hole direction and shape, soil property, burial depth, obstacle type on the diffusion law and hazard range are analyzed. Results show that the leakage gas is not radially diffused until it reaches the ground, and the velocity of gas diffusion to the ground and the hazard range decrease as the angle between the leaking direction and the buoyancy direction increases. Triangular and square leak holes have a faster diffusion rate and a wider hazard range than circular. The diffusion rate of leakage gas in soil rises as soil granularity and porosity increase. The time of leakage gas diffusion to the ground increases significantly with the increase of burial depth, and the hazard range reduces as burial depth increases. Boulder-type obstacles will alter the diffusion path of the leakage gas and accelerate the expansion of the hazard distance, while trench-type obstacles will cause the natural gas to accumulate in the trench and form a high concentration region slowing the expansion of the surface gas concentration.

---

Keywords

---