国家管网集团北京管道有限公司

Extreme weather events have become increasingly frequent in recent years,indicating a trend toward normaliza-tion.During flood seasons,in-service pipelines face significantly heightened risks from various natural disasters,highlighting the urgent need to enhance their flood prevention and control capacity.This paper aims to improve the protection of pipelines laid longitudinally in gullies against mountain torrents and debris flow,particularly under extreme weather conditions.Based on an analysis of the formation mechanisms of debris flow disasters affecting pipelines,as well as an investigation into exist-ing protection facilities in these pipeline sections,the deficiencies in their design are summarized.These deficiencies include a lack of systematic approaches,insufficiently targeted measures,inadequate disaster resistance standards,and structural short-comings.Accordingly,suggestions are proposed,such as strengthening risk assessments,updating design concepts,and imple-menting targeted protective measures.Additionally,the application process of the established comprehensive control strategies is detailed through a specific case study.These strategies were validated during a flood season,demonstrating that the imple-mented protective measures significantly enhanced protection against mountain torrents and debris flow in a section of pipe-line laid longitudinally in a gully in Nanjian village.The outcomes of this study provide a reference for the design of geologi-cal disaster prevention and control in pipeline sections located longitudinally in gullies.

The ongoing development of natural gas pipelines towards elevated pressures and accelerated flow rates increases operating pressures and loads on centrifugal compressors at gas transmission stations.Consequently,challenges such as struc-tural vibration and fatigue fractures become more prominent,threatening the safe operation of these stations.This paper presents an analytical approach that combines theoretical modeling,numerical simulation,and experimental testing through a case analysis focusing on local cracking in a three-stage impeller of a compressor at a station.It also explores the mechanisms behind impeller fractures through fluid-solid coupling research.First,an analysis was conducted to investigate the patterns of aerodynamic load changes on the impeller.Secondly,static experiments were performed to determine the mate-rial strength of the impeller.A finite element model was then established based on the operating conditions to identify the vi-bration characteristics of the impeller through a solving process.Finally,alongside dynamic and static strength analyses,a static strength check and evaluation of fluid-solid coupling resonance risks were conducted to reveal the cracking mecha-nism of the impeller.The maximum stress observed at the root of the inlet blades of the faulty impeller reached 538 MPa during operation,which was lower than the tensile strength and yield strength of the impeller material,measured at 914 MPa and 841 MPa in the experiments,respectively.The pulsation frequency of the airflow across the impeller closely coin-cided with the natural frequencies of the structure in the sixth to eighth orders.These results indicated that the impeller's static strength met the requirements,and the local cracking was related to the frequency of pulsating loads caused by airflow that approached the natural frequencies of the impeller.Thus,fatigue damage caused by resonance is identified as the under-lying cause.The research findings provide a theoretical basis and practical guidance for the safe operation of compressors at gas transmission stations and for the structural optimization of impellers.

To enhance the effectiveness of intelligent site supervision for pipeline engineering and minimize inspection activities at high-risk sites,an intelligent supervision robot system was designed and developed through assessing the current state of intelligent construction sites,identifying operational challenges,and integrating advanced technologies such as edge computing and large models.By fully considering the real environment of pipeline engineering construction,the system incorporated sup-porting software and hardware to form an intelligent all-in-one machine suitable for pipeline engineering supervision,thereby improving the quality of data collected,assisting in the monitoring of the construction process,and reducing the need for on-site human monitoring.