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煤电机组立式离心泵1倍频水平向共振诊断与支撑加固治理

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煤电机组立式离心泵1倍频水平向共振诊断与支撑加固治理

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Diagnosis and support reinforcement of 1X horizontal resonance in a vertical centrifugal pump in a coal-fired power unit

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doi: 10.19666/j.rlfd.202607010

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【目的】面向新一代煤电升级对机组安全可靠、快速启停和智能运维提出的辅机振动安全要求，针对某煤电机组立式离心泵启动调试阶段水平向1倍频振动超限问题，开展现场共振诊断与支撑加固治理研究。

【方法】结合启动运行振动测试、电机空载振动测试和停机固有频率测试，采用频率隔离裕度表征固有频率与转速频率的接近程度，并据此评价现场治理效果。

【结果】处置前，测点1、测点2和测点3水平向振动速度分别为8.37、6.43和5.92 mm/s，均超过4.5 mm/s控制限值，主频稳定在49.95 Hz附近；电机、中间筒体和支撑筒体水平方向一阶固有频率分别为48.74、48.67和47.49 Hz，对应频率隔离裕度仅为2.4%、2.6%和4.9%。采用电机顶部增设水平可调支撑和中间筒体增设加筋板的治理方案后，上述部位水平方向一阶固有频率提高至79.0、66.5和79.0 Hz，频率隔离裕度提高至58.2%、33.1%和58.2%，等效刚度提高约1.87～2.77倍；3个测点水平向振动速度降至2.36、1.69和1.83 mm/s，降幅为69.1%～73.7%，均满足控制限值要求。

【结论】该泵组启动振动超限的主要原因为支撑结构水平方向一阶固有频率接近1倍转速频率所引起的共振；基于频率隔离裕度的现场诊断与治理评价方法可为煤电机组辅机振动安全和同类立式泵共振故障处置提供工程参考。

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[Objective] Excessive horizontal vibration dominated by the once-per-revolution (1X) frequency component was observed in a vertical centrifugal pump during commissioning of a coal-fired power unit. This study aimed to distinguish structural resonance from rotor, electrical, bearing, connection, and operating-condition faults and to evaluate a field reinforcement strategy.

[Methods] Start-up vibration velocity, spectra, and phase were recorded at three heightwise locations on the motor and supporting cylinders in the horizontal, vertical, and axial directions. Motor no-load measurements were used to assess whether the response depended on hydraulic load, while shutdown external-excitation response tests were used to identify the first-order horizontal natural frequencies of the motor, intermediate cylinder, and support cylinder. Common fault sources were screened using the available online balancing check, connection inspection, operating records, electrical observations, and bearing and electromagnetic frequency features. A frequency-separation margin was calculated to quantify proximity to the 49.95 Hz 1X excitation and was treated as a continuous descriptive quantity rather than a fixed risk or acceptance threshold. The equivalent-stiffness ratio was estimated from the squared natural-frequency ratio only when the same mode was tracked, the boundary conditions were comparable, and the added mass was small. The retained historical records documented the instrument model, measurement positions and directions, operating states, and measured peaks, but did not preserve the complete acquisition configuration; this limitation is stated explicitly.

[Results] Before reinforcement, the horizontal vibration velocities at measurement points 1, 2, and 3 were 8.37, 6.43, and 5.92 mm/s, respectively, all above the site start-up control value of 4.5 mm/s. Horizontal response increased with structural height and remained dominated by 1X. During no-load operation, the horizontal velocities at the motor non-drive end, motor drive end, intermediate-cylinder upper flange, and intermediate position were 4.09, 3.16, 3.07, and 2.41 mm/s, respectively, while the recorded spectra remained 1X-dominant. The first-order horizontal natural frequencies of the motor, intermediate cylinder, and support cylinder were 48.74, 48.67, and 47.49 Hz, giving separation margins of only 2.4%, 2.6%, and 4.9%. These mutually consistent observations supported a diagnosis of insufficient lateral support stiffness. An adjustable horizontal support was therefore added at the motor top, and axial stiffening ribs were added to the intermediate cylinder. After reinforcement, the corresponding natural frequencies increased to 79.0, 66.5, and 79.0 Hz, and the separation margins increased to 58.2%, 33.1%, and 58.2%. The estimated relative stiffness multipliers were 2.63, 1.87, and 2.77. The horizontal start-up velocities decreased to 2.36, 1.69, and 1.83 mm/s, representing reductions of 69.1% to 73.7%, and all values were below the site control value.

[Conclusions] The agreement among direction-dependent start-up response, persistent no-load 1X response, natural-frequency proximity, frequency migration, and post-treatment vibration reduction identifies horizontal structural resonance as the dominant fault mechanism in this pump unit. The combined diagnostic path is useful for similar field cases when speed and boundary conditions are stable and competing fault sources have been examined, but the case-specific margins should not be treated as universal acceptance criteria.

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. 煤电机组立式离心泵1倍频水平向共振诊断与支撑加固治理. 热力发电, : - . DOI: 10.19666/j.rlfd.202607010

. Diagnosis and support reinforcement of 1X horizontal resonance in a vertical centrifugal pump in a coal-fired power unit[J]. Thermal Power Generation, : - . DOI: 10.19666/j.rlfd.202607010

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doi: 10.19666/j.rlfd.202607010

首发时间：2026-10-16

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2种不同金属材料的力学参数

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

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