The high-pressure fire-resistant oil system is the core power unit of the steam turbine electro-hydraulic control (EH) system, and its reliability is directly related to the operation safety and regulation accuracy of the steam turbine unit. As a key device of the system, the EH main oil pump PVH098R01AJ30A250000002001AB010A undertakes the core task of providing a stable high-pressure oil source for the speed control system. However, in long-term operation, abnormal vibration and bearing wear problems may cause the performance degradation of the oil pump or even failure shutdown. This paper combines the structural characteristics of the pump with the system operation requirements, focusing on the analysis of its vibration control strategy and bearing wear monitoring method in the high-pressure EH oil system.

I. Structural characteristics and vibration source analysis of PVH098R01AJ30A250000002001AB010A main oil pump

PVH098 main oil pump adopts variable straight-axis plunger pump design, realizes flow regulation through a swing swash plate structure, and has high pressure (31.5MPa), large flow (98.3cm³/r) and fast response characteristics. Its core vibration sources mainly include:

• Mechanical vibration: the periodic reciprocating motion of the plunger and the cylinder, the coupling misalignment, the centrifugal force generated by the high-speed rotation of the impeller, etc. can all cause mechanical vibration.
• Fluid vibration: the pressure pulsation of high-pressure oil in the pump chamber, the cavitation effect of gas-containing oil, and the resonance of the pipeline system may amplify the vibration amplitude.
• Electromagnetic vibration: the electromagnetic force fluctuation caused by the uneven magnetic field of the drive motor or the sudden change of load may be transmitted to the pump body through the coupling.

In addition, the physical and chemical properties of EH oil (such as viscosity, water content, and particle contamination) directly affect the stability of the oil film and indirectly increase the risk of vibration and wear.

II. Vibration control strategy of high-pressure EH oil system

For the vibration characteristics of the PVH098R01AJ30A250000002001AB010A EH oil main pump, comprehensive control needs to be implemented from three levels: system design, operation and maintenance, and monitoring optimization:

1. Structural design and installation optimization

Vibration reduction component integration: The pump group base is equipped with a shock-absorbing coupling and a damping support to absorb mechanical vibration energy.

Optimization of pipeline layout: Use hose connection to buffer pressure shock and avoid fluid resonance caused by right-angle bending of hard pipe.

Fire-resistant oil quality management: Regularly test oil resistivity (≥6.0×10⁹Ω·cm) and acid value (≤0.1mgKOH/g) to prevent oil quality degradation and lubrication performance degradation.

2. Operation parameter regulation

Oil temperature control: Maintain the oil temperature at 30-60℃ through the cooling system to avoid high temperature aggravating oil oxidation or low temperature causing viscosity increase.

Start-stop operation specification: Perform a 10-hour pre-lubrication cycle before starting to reduce the risk of dry friction of the plunger assembly; strictly follow the “start first and stop later” principle when switching the standby pump to avoid sudden pressure changes.

III. Bearing wear monitoring and protection technology

As the core load-bearing component of the PVH098R01AJ30A250000002001AB010A main oil pump, the wear state of the bearing directly affects the life of the pump unit. Wear monitoring needs to combine indirect parameter analysis with direct detection technology:

1. Indirect monitoring indicators

Oil analysis: Regularly detect the pollution degree of fire-resistant oil particles (NAS≤6 level), and identify the composition and concentration changes of bearing alloy abrasive particles through iron spectrum analysis.

Abnormal operating parameters: Increased pump current (such as from 32A to 47A), abnormal outlet pressure difference (>0.5MPa), etc. may reflect increased bearing clearance or poor lubrication.

2. Direct detection technology

Vibration spectrum diagnosis: In the early stage of bearing wear, characteristic harmonics will appear in the high frequency band, and the envelope demodulation technology can be used to accurately locate the damage position.

Infrared thermal imaging: Monitor the temperature distribution of the outer ring of the bearing. Local overheating indicates lubrication failure or abnormal contact stress.

3. Wear protection measures

Lubrication system enhancement: Use oil-gas lubrication technology to improve the oil film bearing capacity, and regularly replace mechanical seals to prevent moisture and impurities from invading.

Material upgrade: Micro-arc welding is used to repair the severely worn journals, the surface hardness is increased to above HRC55, and the thickness of the bearing alloy layer is optimized (≥0.2mm).

The stable operation of the PVH098R01AJ30A250000002001AB010A main oil pump in the high-pressure fire-resistant oil system depends on the synergy of multi-dimensional vibration control and refined wear monitoring. By optimizing the structural design and strengthening the oil quality supervision, mechanical and fluid vibrations can be effectively suppressed and the service life of the bearing can be extended.

When looking for high-quality, reliable steam turbine oil pumps, YOYIK is undoubtedly a choice worth considering. The company specializes in providing a variety of power equipment including steam turbine accessories, and has won wide acclaim for its high-quality products and services. For more information or inquiries, please contact the customer service below:
E-mail: sales@yoyik.com
Tel: +86-838-2226655
Whatsapp: +86-13618105229

Yoyik offers various types of spare parts for steam turbines, generators, boilers in power plants:
accumulator charging kit nitrogen NXQ-A1010 FY
MOTOR YBX3-250M-4-55KW
Stop valve J61H-1500SPL
Power plant shut-off valves WJ32F3.2P
Sealing components KHWJ5160F1.6P
Pump casing wearring PCS1002002380010-01/502.02
Globe valve KHWJ61F1.6P
Ball valve Q11F-16C
bladder with seal kit NXQ-AB-63/31.5-L-Y
Hydraulic accumulator bladder & Seal kit NXQ-AB-80/31.F
gate Z61Y-300LB
gate Z41Y-25I
Cooling fan YP2-90L-2
Electric stop valve J961Y-100I
mechanical seal manufacturers A108-45
gate Z964Y-250
Accumulator rubber bag 40L butyl
BLADDER FOR ACCUMU NXQAB-100/31.5-L-Y
High outlet plug valve SD61H-P55185V SA-182 F91
Stop valve J61Y-900LB
Electric stop valve J961Y-P55.5140V ZG15Cr1MoV
electric solenoid J-110VDC-DN10-DOF/20D/2N
centrifugal pump industry YCZ50-250C
SERVO VALVE SM4 20 (15) 57 80/40 10 S182
EH oil pump relief valve 2″LOF-98H
accumulator seals NXQ-A-16L/20F-Y
Electric stop valve J961Y-250 SA-105
One-way valve 126*48mm
Check valve H64Y-1500Lb
set glove valve along with electric actuator. 100J941Y40
Hydraulic Accumulator NXQ 2 5/31.5-L-Y
trip overspeed cover plate HGPCV-02-B30
Servo valve of speed control system G761-3027B