Abstract
Against the background of China’s growing natural gas demand and improving long-distance pipeline network, compressors, as the core equipment for natural gas booster transportation, directly determine the stability of pipeline network operation and gas supply reliability. Centrifugal and reciprocating compressors are the most widely used in long-distance pipelines. However, affected by multiple factors such as equipment, electrical, working conditions and personnel, they are prone to failures including unplanned shutdown, performance degradation and mechanical damage, which seriously affect continuous transportation. This paper systematically sorts out the typical failure causes of the two mainstream compressors, analyzes the root causes from four dimensions of mechanical failure, control system, external working conditions and personnel management, and puts forward targeted prevention, control and governance countermeasures, providing technical reference and management schemes for the safe and efficient operation of long-distance pipeline compressors and reducing failure rates.
1. Core Role of Compressors in Natural Gas Long-Distance Pipelines
Natural gas long-distance pipelines rely on compressors to achieve pressure boost and stable transportation. Their functions are to reduce transmission loss, realize uniform gas supply, with high efficiency, stability and operational safety. They are the key equipment to ensure pipeline connectivity and cross-regional continuous gas supply. Once a compressor fails, it will directly lead to gas supply interruption, abnormal pressure, rising energy consumption and even safety risks. Therefore, failure prevention and rapid disposal are crucial to the natural gas long-distance transmission system.
2. Analysis of Main Fault Types and Causes of Long-Distance Pipeline Compressors
The mainstream configurations of long-distance pipelines are centrifugal compressors and reciprocating compressors, which have different failure characteristics and causes, as well as common problems.
2.1 Causes of Centrifugal Compressor Faults
Centrifugal compressor failures are mostly manifested as sudden shutdowns, with two main causes:
One is
equipment body failure, with poor stability of control system and gas system, easily triggering protective shutdown;
The other is
external working condition fluctuation, sudden changes in power supply and gas supply conditions exceeding the equipment operation range, leading to protective shutdown.
2.2 Causes of Reciprocating Compressor Faults
Reciprocating compressor failures are also dominated by shutdowns, with three main incentives:
Equipment body failure, similar to centrifugal type;
Lubrication system abnormality, low oil pressure causing wear of moving parts and abnormal operation;
Deflagration phenomenon, causing emergency shutdown.
In addition, both types of compressors have key mechanical component damage, with rotor damage being the most typical. It is mostly caused by no testing, recording and repair of vibration transmission lines before startup, leading to flow calculation deviation. The unit operates in the blocking area for a long time, eventually causing rotor failure and complete machine breakdown. Burnout of stationary blades is also a common mechanical fault, caused by corrosion of combustion chamber induced by hydrocarbons in natural gas, combined with improper temperature control and excessive temperature fluctuation.
2.3 Control System and Electrical Faults
Control system failure is the main cause of compressor shutdown, mainly manifested in three types:
False signal transmission,
software failure (false alarm),
hardware failure (module damage, loose wiring).
Poor grounding, instantaneous loose wiring and program logic defects will cause signal distortion and malfunction, leading to unplanned shutdown.
2.4 Influence of External Factors
Unstable external working conditions are important incentives:
Power supply factor: External power interruption, voltage fluctuation and power loss impact the stable operation of the unit;
Gas supply factor: Filter blockage, gas quality fluctuation and poor steam quality lead to abnormal intake conditions and trigger protective shutdown.
2.5 Shortcomings of Personnel Skills and Management
Insufficient professional ability and low sense of responsibility of operation and maintenance personnel are important reasons for fault expansion and recurrence:
Lack of ability to identify fault precursors and unable to predict and dispose in advance;
No standardized record after troubleshooting, leading to repeated similar problems and low maintenance efficiency;
Inadequate daily inspection and maintenance, long-term accumulation of hidden dangers, eventually inducing failures.
3. Countermeasures for Compressor Faults in Natural Gas Long-Distance Pipelines
3.1 Strengthen Mechanical Fault Prevention and Precise Maintenance
For rotor damage: Vibration transmission line testing, verification and recording must be completed before startup to ensure accurate flow calculation, avoid unit operation in blocking area and eliminate rotor faults from the source.
For stationary blade burnout: Strictly monitor combustion chamber temperature and control temperature fluctuation amplitude; After failure, trace the temperature change trend, assist detection to locate the cause, and implement anti-corrosion control to avoid combustion efficiency decline and equipment life loss.
3.2 Improve Reliability of Control System and Electrical System
Optimize signal management: Install false signal filtering devices to reduce signal interference and mistransmission;
Improve grounding system: Eliminate loose wiring and poor contact;
Strengthen software and hardware control: Regularly inspect system modules, replace damaged parts in time; Optimize alarm program, adopt manual analysis for abnormal data to reduce software misjudgment rate;
Standardize hardware management: Establish vulnerable parts evaluation and replacement mechanism to ensure stable operation of control system.
3.3 Avoid Faults Caused by External Factors
Stable power supply guarantee: Strengthen communication with power supply departments to ensure stable external power; Improve the operation and maintenance quality of generator sets, optimize the station's self-power supply system to resist voltage fluctuation and interruption.
Stable gas supply guarantee: Regularly clean filters and replace filter elements on schedule to prevent blockage; Install separators to improve steam quality and intake conditions, and eliminate gas supply failure incentives.
3.4 Improve Professional Quality and Management Level of Operation and Maintenance Personnel
Strengthen skill training: Carry out regular practical and fault disposal training to improve hidden danger identification and rapid maintenance capabilities;
Enhance professional quality: Implement inspection and maintenance responsibilities, standardize fault records and form traceable accounts;
Improve management mechanism: Clarify operation and maintenance processes, strengthen assessment and supervision, and promote active maintenance and precise disposal.
Conclusion
The compressor is the "heart" of natural gas long-distance pipelines, and its stable operation is directly related to gas supply safety and people's livelihood security. For the typical faults of centrifugal and reciprocating compressors, collaborative governance is required from four aspects: mechanical system, control system, external working conditions and personnel management. Through preventive maintenance, technical optimization, standardized management and skill improvement, early detection, early disposal and non-recurrence of faults can be realized, and the operational reliability of compressors and the gas supply stability of long-distance pipeline network can be continuously improved.
