scholarly journals Analysis of Vibration Characteristics of Centrifugal Pump Mechanical Seal under Wear and Damage Degree

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Yin Luo ◽  
Wenqi Zhang ◽  
Yakun Fan ◽  
Yuejiang Han ◽  
Weimin Li ◽  
...  
Keyword(s):  
Shock Wave ◽  
Centrifugal Pump ◽  
Frequency Spectrum ◽  
Flow Rate ◽  
Vibration Amplitude ◽  
Vibration Signal ◽  
Mechanical Seal ◽  
Centrifugal Pumps ◽  
Time Frequency ◽  
Seal Failure

Mechanical seal is a kind of shaft sealing equipment. Face wear is one of the main causes of mechanical seal failure. Mechanical seal condition is also related to the reduction of energy consumption and carbon emission. Therefore, we need to detect the centrifugal pump seal condition. At present, vibration signal is a common method for fault monitoring and diagnosis of centrifugal pump. In this paper, the vibration signal under the condition of damaged centrifugal pump seal is measured by studying the characteristics of vibration signal after the end face damage of centrifugal pump. Statistical indicators such as RMS and kurtosis were taken to analyze the average energy and shock wave energy of vibration signal. The time-frequency characteristics of vibration signal are analyzed by frequency spectrum. The results show that there are a large extent variation of vibration amplitude in the direction of base and axis and a weak variation of vibration amplitude in the direction of radial and vertical. With the increasing of flow rate, the RMS of vibration signal falls at first, then keeps steady, and mounts at last when the flow rate is over the design flow rate. It can be shown from the time-frequency spectrum that there is a shock wave and pause signals caused by the shock wave, which are reflected by the higher frequency band components of the vibration signal that can provide a reference to the diagnosis of the occurrence of damaged mechanical seal. From the analysis, the energy of vibration signal is related to the running condition, we can find that the occurrence of mechanical seal wear makes the centrifugal pump to produce high-frequency vibration signal, and the axial vibration is the strongest and the instability in the fluid makes the vibration signal produce high amplitude characteristics. Analyzing the vibration signal characteristics of centrifugal pumps with damaged mechanical seal is of great significance to find the mechanical seal failure of the centrifugal pumps and adjust the operating parameters.

Research on stator current characteristics of centrifugal pumps under different mechanical seal failures

2021 ◽  
pp. 095440622110610
Author(s):  
Jiamin Zou ◽  
Yin Luo ◽  
Yuejiang Han ◽  
Yakun Fan
Keyword(s):  
Centrifugal Pump ◽  
Negative Impact ◽  
Maximum Amplitude ◽  
Mechanical Seal ◽  
Centrifugal Pumps ◽  
Pump System ◽  
Seal Failure ◽  
Stator Current ◽  
Marginal Spectrum ◽  
Current Characteristics

Mechanical seal failure has a great negative impact on the operation of a centrifugal pump system. A method to analyze the stator current characteristics of the motor in a centrifugal pump system is proposed to monitor the internal flow of the centrifugal pump and to identify the failure status of the mechanical seal. Experiments were conducted under different mechanical seal states. Based on sensorless technology, the stator current signal of the motor is collected, processed by windowing function, anti-aliasing filter, singular value decomposition, Hilbert–Huang transform, and the marginal spectrum of correlation quantity is drawn. The results show that according to the external characteristic curve of the centrifugal pump, after the failure of the mechanical seal, the head and efficiency of the centrifugal pump decrease, and the head is greatly affected by the degree of failure, while the degree of mechanical seal failure has little effect on the shaft power of the centrifugal pump; the centrifugal pump has good operation stability under design conditions or near slightly large flow; the stability of centrifugal pump operation decreases with the aggravation of mechanical seal failure; the corresponding maximum amplitude in the marginal spectrum can be used as an index to diagnose the damage degree of the mechanical seal.

Reform of Mechanical Shaft Sealing Self-Flush System of Petrochemical Hot Oil Centrifugal Pump

2013 ◽  
Vol 331 ◽  
pp. 106-109
Author(s):  
Yan Liu ◽  
Jie Long Ren ◽  
Hui Cao
Keyword(s):  
Centrifugal Pump ◽  
Mechanical Seal ◽  
Centrifugal Pumps ◽  
Shaft Seal ◽  
Research Focus ◽  
Seal Failure ◽  
Main Fault ◽  
Flush Fluid ◽  
The Way

Mechanical seal leakage of centrifugal pumps (especially hot oil pumps) is the main fault reason of the petrochemical equipments. The fuction of the sealing flush system is to maintain the mechanical shaft seal function correctly. The misconduct of flush system settings will directly lead to the failure of mechanical seal. In this paper, the problems are analyzed for the present mechanical seal flushing system. When the centrifugal pump is in a standby state, flushing system may not provide normal flush flow in self-flush plan. This may lead to surface fouling of the hot mechanical shaft seal, resulting in seal failure. Our research focus on solving these problems. The way is to change the source of flush fluid, that is to change the flush plan to external flush plan or toChange the fluid pipe position.

scholarly journals Pengaruh tipe bantalan bola pada poros pompa sentrifugal terhadap sinyal getaran

2018 ◽  
Vol 16 (1) ◽  
pp. 25
Author(s):  
Ibnu Hajar
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Ball Bearing ◽  
Roller Bearing ◽  
Vibration Signal ◽  
Centrifugal Pumps ◽  
Processing Industry ◽  
Pump Shaft ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller

Pompa sentrifugal merupakan salah satu pompa yang sangat banyak digunakan pada industri pengolahan, seperti industri pengolahan air minum, industri pengolahan minyak, dan pabrik kelapa sawit. Bentuknya sederhana dan biaya perawatan lebih murah. Permasalahan yang sering terjadi pada pompa sentrifugal adalah kerusakan pada bantalan poros yang diakibatkan oleh getaran, keausan, dan misalignment. Pada makalah ini membahas pengaruh tipe bantalan bola terhadap sinyal getaran poros pompa sentrifugal satu tingkat. Tujuan penelitian ini adalah mengetahui dan mendapatkan pengaruh tipe bantalan bola pada poros pompa sentrifugal dengan mengukur sinyal getaran. Pompa yang digunakan dalam penelitian ini adalah pompa sentrifugal yang mempunyai head tekanan  9 meter, debit aliran 3 liter/detik dan daya output 746 watt. Metode penelitian dengan mengamati dan analisis perilaku sinyal getaran yang terdiri dari simpangan (displacement), kecepatan( velocity) dan percepatan (acceleration) pada bantalan bola pompa sentrifugal pada titik P-01 dan P-02 dari arah aksial, vertikal dan horizontal. Pengukuran sinyal getaran dilakukan dengan menggunakan alat ukur Vibrometer Analog VM-3314A. Bantalan (bearing) yang gunakan dalam penelitian ini adalah tipe cylindrical roller bearing dan  roller ball bearing yang dipasang pada poros pompa sentrifugal untuk diamati dan ukur sinyal getarannya. Hasil pengujian menunjukkan bahwa harga simpangan tertinggi 37,125 µm terjadi bantalan tipe ball bearing arah horizontal pada titik pengukuran P-02 tinggi tekan 3 meter dengan debit aliran 2,8 liter/detik. Sedangkan harga simpangan terendah  27,1 µm terjadi pada cylindrical roller bearing dengan tinggi tekan 3 meter dan debit aliran 2,8 liter/detik. Dengan naiknya tinggi tekan pada pompa sentrifugal menyebabkan turunnya getaran pompa sesuai penurunan beban pada pompa, sehingga untuk pompa sentrifugal satu tingkat lebih aman menggunakan tipe cylindrical roller bearing.Kata kunci: Tipe bantalan, pompa sentrifugal, sinyal getaranAbstractCentrifugal pumps are one of the most widely used pumps in the processing industry, such as the drinking water treatment industry, the oil processing industry and the palm oil mill, in addition to the simpler and cheaper maintenance costs. The most common problem with centrifugal pumps is damage to the shaft bearings caused by vibration, wear and misalignment. This paper discusses the effect of ball bearing type on the single-stage centrifugal pump vibration signal. The purpose of this research is to know and get the influence of ball bearing type on centrifugal pump shaft by measuring vibration signal. The pumps used in this study are centrifugal pumps that have a 9-meter pressure head, a flow rate of 3 liters / second and a power output of 746 watts. Research method by observing and analyzing vibration signal behavior consist of displacement, velocity and acceleration on centrifugal pump ball bearing at point P-01 and P-02 from axial, vertical and horizontal direction. Measurement of vibration signal is done by using Analog Vibrometer VM-3314A. Bearings used in this study are cylindrical roller bearing and roller ball bearings mounted on the centrifugal pump shaft to be observed and measure the vibration signal. Test results showed that the highest deviation 37,125 μm occurred bearing type ball bearing horizontal direction at the point of measurement P-02 high press 3 meter with flow debit 2,8 liter / second. While the lowest 27.1 μm deviation occurred in cylindrical roller bearing with 3 meter press and 2.8 liter / second flow rate. With the increase in the height of the tap on the centrifugal pump causes the decrease of pump vibration according to the load decrease at the pump, so for the centrifugal pump one level safer using cylindrical roller bearing type

Experimental Investigation of Pressure Fluctuations on Inner Wall of a Centrifugal Pump

2019 ◽  
Vol 36 (4) ◽  
pp. 401-410 ◽  
Author(s):  
Xiao-Qi Jia ◽  
Bao-Ling Cui ◽  
Zu-Chao Zhu ◽  
Yu-Liang Zhang
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Pressure Fluctuation ◽  
Pressure Fluctuations ◽  
High Flow ◽  
Low Flow ◽  
Centrifugal Pumps ◽  
Flow Rates ◽  
Pressure Distributions ◽  
Blade Passing Frequency

Abstract Affected by rotor–stator interaction and unstable inner flow, asymmetric pressure distributions and pressure fluctuations cannot be avoided in centrifugal pumps. To study the pressure distributions on volute and front casing walls, dynamic pressure tests are carried out on a centrifugal pump. Frequency spectrum analysis of pressure fluctuation is presented based on Fast Fourier transform and steady pressure distribution is obtained based on time-average method. The results show that amplitudes of pressure fluctuation and blade-passing frequency are sensitive to the flow rate. At low flow rates, high-pressure region and large pressure gradients near the volute tongue are observed, and the main factors contributing to the pressure fluctuation are fluctuations in blade-passing frequency and high-frequency fluctuations. By contrast, at high flow rates, fluctuations of rotating-frequency and low frequencies are the main contributors to pressure fluctuation. Moreover, at low flow rates, pressure near volute tongue increases rapidly at first and thereafter increases slowly, whereas at high flow rates, pressure decreases sharply. Asymmetries are observed in the pressure distributions on both volute and front casing walls. With increasing of flow rate, both asymmetries in the pressure distributions and magnitude of the pressure decrease.

Clocking effect in a centrifugal pump with a vaned diffuser

2020 ◽  
Vol 34 (26) ◽  
pp. 2050286
Author(s):  
Fen Lai ◽  
Xiangyuan Zhu ◽  
Yongqiang Duan ◽  
Guojun Li
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Pressure Loss ◽  
Total Pressure ◽  
Radial Force ◽  
Design Flow ◽  
Total Pressure Loss ◽  
Inlet Section ◽  
Centrifugal Pumps ◽  
Installation Angle

The performance and service life of centrifugal pumps can be influenced by the clocking effect. In this study, 3D numerical calculations based on the k-omega shear stress transport model are conducted to investigate the clocking effect in a centrifugal pump. Time-averaged behavior and transient behavior are analyzed. Results show that the optimum diffuser installation angle in the centrifugal pump is [Formula: see text] due to the minimum total pressure loss and radial force acting on the impeller. Total pressure loss, particularly in the volute, is considerably influenced by the clocking effect. The difference in total pressure loss in the volute at different clocking positions is 2.75 m under the design flow rate. The large total pressure loss in the volute is primarily caused by the large total pressure gradient within the vicinity of the volute tongue. The radial force acting on the impeller is also considerably affected by the clocking effect. When the diffuser installation angle is [Formula: see text], flow rate fluctuations in the volute and impeller passage are minimal, and flow rate distribution in the diffuser passage is more uniform than those in other diffuser installation angles. Moreover, static pressure fluctuations in the impeller midsection and the diffuser inlet section are at the minimum value. These phenomena explain the minimum radial force acting on the impeller. The findings of this study can provide a useful reference for the design of centrifugal pumps.

Design Optimization of Splitter Blade Impeller in a Centrifugal Pump

2020 ◽  
Author(s):  
Shunya Takao ◽  
Kentarou Hayashi ◽  
Masahiro Miyabe
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Design Method ◽  
General Purpose ◽  
Stable Operation ◽  
Centrifugal Pumps ◽  
Unstable Flow ◽  
Rate Range ◽  
Flow Rate Range ◽  
Suction Performance

Abstract In order to improve suction performance, centrifugal pumps with an inducer are used for rocket pumps, liquid gas transport such as LNG, and general-purpose pumps. Since a higher suction performance than conventional pump is required, a splitter blade that consists of a long blade and a short blade is sometimes adopted. However, the design becomes more difficult due to the increased number of parameters. The stable operation over a wide flow rate range are required in the general-purpose pumps. Therefore it is necessary to design them so that unstable flow phenomena such as surges do not occur. However, the design method to avoid them is not well understood yet. In this study, we focused on the splitter blade impeller in a general-purpose low-speed centrifugal pump with an inducer. Six parameters such as leading edge position and trailing edge position of the short blade for both hub-side and tip-side were set as design ones. A multi-objective optimization method using a commercial software was applied to improve suction performance while maintaining high efficiency. Then obtained optimal shape were analyzed by CFD calculation and extracted the feature. Furthermore, optimized impellers were manufactured and confirmed the performance over a wide flow rate range by experiments. In addition, a optimizing design method that improves pump performance at lower cost was studied.

Centrifugal Pump Leak-Free Technology Introduction and Its Applications in EPR Nuclear Power Plant

2010 ◽  
Author(s):  
Guohui Cong ◽  
Ling Zhang
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Centrifugal Pump ◽  
Nuclear Power ◽  
Operating Conditions ◽  
Critical Conditions ◽  
Mechanical Seal ◽  
Centrifugal Pumps ◽  
Canned Motor ◽  
Magnetic Drive

Environmental protection requirement is more and more critical now, and it increases the request to prevent dangerous liquid to leak outside in nuclear power plant too. Centrifugal pumps are the most important active equipments in nuclear power plant, but there is a shaft clearance between rotor and stator of centrifugal pump. The shaft clearance can lead pumped fluid to the outside, so the environment may be polluted by the leakage. In some critical conditions such as transferring high radioactive fluid in the pump, the leakage shall be totally forbidden. So solutions have to be found to make centrifugal pumps totally leak-free for applications in nuclear power plant. Normally there are three leak-free technologies for centrifugal pumps: mechanical seal with auxiliary system, canned motor and magnetic drive. In this paper, all the three leak-free technologies and some of their applications in EPR 3rd generation PWR nuclear power plants are presented and discussed. The results show that in EPR nuclear power plant, canned motor pumps can be preferably used for strict environmental requirement of leak-free if the pump power and operating conditions are applicable. For other conditions, pumps with double mechanical seal can also be used with additional sealing water system support. For centrifugal pumps with magnetic drive are not so applicable in high pressure condition, and the safety aspect is weaker than canned motor pumps, generally they are not used in EPR nuclear power plant at present.

scholarly journals Analysis of the number and angle of the impeller blade to the performance of centrifugal pump

2021 ◽  
pp. 62-68
Author(s):  
Sugeng Hadi Susilo ◽  
Agus Setiawan
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Flow Simulation ◽  
Maximum Output ◽  
Centrifugal Pumps ◽  
Impeller Blade ◽  
Pump Performance ◽  
Solid Works ◽  
Discharge Pressure

The paper discusses the performance of the pump in relation to the impeller. The impeller section is determined by the number and angle of the blades. Therefore, the purpose of this study was to analyze the role of the number and angle of impeller blades on the performance (discharge and discharge pressure) of centrifugal pumps based on experiments and simulations. The method used is experiment and simulation. Using a centrifugal pump type GWP 20/4 SW, Maximum Output: 6.5 HP/3500 rpm, Inlet/Outlet: 2 Inch, Dimensions: 475x375x370 mm. Experiments and simulations by varying the number of blades 2, 4, and 6 with a blade tilt angle of 130°, 150°, and 160°. For flow simulation using solid works program. The results show that pump performance is related to discharge pressure, impeller with 2-blades and an angle of 130° the pressure increases 0.45–2.45 bar, for 150° increases 0.14–2.96 bar, and 160° increases 0.29–3.07 bars. For a 4-blade impeller and an angle of 130°, the pressure increases by 0.48–3.12 bar, for 150° it increases by 0.39–3.39 bar, and for 160° it increases by 0.36–3.48 bar. While the impeller for 6-blades with an angle of 130° the pressure increases from 0.6 bar to 3.72 bar, for 150° increases from 1.36 to 4.34 bar, and 160° increases by 0.36–4.74 bar. While it related pump performance to flow rate, increasing the number of blades causes a decrease in flow rate. The highest flow rate is in a 2-blade impeller with a blade angle of 130° is 404.91 l/s. The lowest flow rate is on a 6-blade impeller with an angle of 160° is 279.66 l/s

Numerical Study of a Fuel Centrifugal Pump with Variable Impeller Width for Aero-engines

2015 ◽  
Vol 32 (4) ◽  
Author(s):  
Bin Wang ◽  
Huasheng Guan ◽  
Zhifeng Ye
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Numerical Study ◽  
High Reliability ◽  
Low Flow ◽  
Centrifugal Pumps ◽  
Fuel Temperature ◽  
Low Efficiency ◽  
Aero Engines ◽  
Large Flow

AbstractAs typical pump with large flow rate and high reliability, centrifugal pumps in fuel system of aero-engines mostly regulate flow rate by flow bypass, which leads to low efficiency and large fuel temperature rise especially at low flow rate. An innovative fuel centrifugal pump with variable impeller width is a more effective way to regulate flow rate than flow bypass. To find external characteristics of the centrifugal pump with variable impeller width proposed in this paper, flow domain within the pump is simulated numerically and some primary performance parameters and their correlation are analyzed. Results show that flow rate of the pump can be regulated by variable impeller width and that efficiency for this scheme is higher than that for flow bypass. The higher outlet static pressure the pump runs at, the wider range of flow rates can be obtained with stronger nonlinear relationship between flow rate and impeller width.

scholarly journals Influence of Balance Hole Diameter on Leakage Flow of the Balance Chamber in a Centrifugal Pump

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Wei Dong ◽  
Diyi Chen ◽  
Jian Sun ◽  
Yan Dong ◽  
Zhenbiao Yang ◽  
...  
Keyword(s):  
Centrifugal Pump ◽  
Axial Force ◽  
Flow Rate ◽  
Volume Flow Rate ◽  
Vortex Motion ◽  
Internal Flow ◽  
Hole Diameter ◽  
Leakage Flow ◽  
Centrifugal Pumps ◽  
Axial Thrust

The balancing holes in centrifugal pumps with seals mounted in both suction and discharge sides are one of the approaches used by pump manufacturers to reduce the axial thrust. The balance hole diameter directly affects the axial force of the centrifugal pump. The flow characteristics in the balance chamber are closely related to the balance hole diameter. However, research is not very clear on the internal flow of the balanced chamber, due to the small axial and radial sizes and the complicated flow conditions in the chamber. In this paper, we analyzed the influence of the balance hole diameter on the liquid leakage rate, flow velocity, and vortex motion in the balance chamber. The results indicated that when the balance hole diameter was lower than the design value, the volume flow rate of leakage flow was proportional to the diameter. The liquid flow rate and vortex distribution rules in the balance chamber were mainly associated with the coeffect of radial leakage flow in the rear sealing ring interval and the axial balance hole leakage flow. The research has revealed the mechanisms of leakage flow of the balance chamber in the centrifugal pump and that this is of great significance for accurate calculation and balancing of the axial force.

Sign in / Sign up

Export Citation Format

Share Document