To address the vibration over‑limit issue of a horizontally split multistage pump in the water intake system of a coastal city's pipeline network,vibration velocity testing and spectrum characteristic analysis were carried out using the LMS testing and analysis system.The results showed that the peak vibration velocity in the vertical direction at the non‑drive end of the pump reached 13.8 mm/s,far exceeding the limit specified in the GB/T 29531—2013 standard,posing a serious challenge to the safety and stability of the equipment.To accurately identify the root cause of the fault,a quantitative risk assessment of potential failures was conducted based on the failure mode and effects analysis (FMEA) method.Through failure mode identification,risk priority number (RPN) calculation,and screening of key fault factors,pump shaft misalignment and rotor‑stator interaction between the impeller and casing were determined to be the core causes of the excessive vibration.Accordingly,improvement measures including high‑precision shaft alignment correction,impeller hydraulic profile optimization,and clearance matching adjustment were proposed and implemented.After the improvements,the dominant vibration frequency of the pump was effectively shifted.The dominant frequency amplitudes in the horizontal and vertical directions at the non‑drive end were reduced by 52.6% and 51.5%,respectively.The vibration severity met the operational requirements for Class Ⅱ equipment specified in the GB/T 29531—2013 standard,and the equipment operating condition was significantly improved.This study provides a reference for the accurate diagnosis and efficient treatment of vibration faults in fluid machinery equipment,and holds important engineering application value for ensuring the reliable operation of urban pipeline network water intake systems.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |