Multistage Centrifugal Pump Fault Diagnosis Using Informative Ratio Principal Component Analysis

This study proposes a fault diagnosis method (FD) for multistage centrifugal pumps (MCP) using informative ratio principal component analysis (Ir-PCA). To overcome the interference and background noise in the vibration signatures (VS) of the centrifugal pump, the fault diagnosis method selects the fault-specific frequency band (FSFB) in the first step. Statistical features in time, frequency, and wavelet domains were extracted from the fault-specific frequency band. In the second step, all of the extracted features were combined into a single feature vector called a multi-domain feature pool (MDFP). The multi-domain feature pool results in a larger dimension; furthermore, not all of the features are best for representing the centrifugal pump condition and can affect the condition classification accuracy of the classifier. To obtain discriminant features with low dimensions, this paper introduces a novel informative ratio principal component analysis in the third step. The technique first assesses the feature informativeness towards the fault by calculating the informative ratio between the feature within the class scatteredness and between-class distance. To obtain a discriminant set of features with reduced dimensions, principal component analysis was applied to the features with a high informative ratio. The combination of informative ratio-based feature assessment and principal component analysis forms the novel informative ratio principal component analysis. The new set of discriminant features obtained from the novel technique are then provided to the K-nearest neighbor (K-NN) condition classifier for multistage centrifugal pump condition classification. The proposed method outperformed existing state-of-the-art methods in terms of fault classification accuracy.

Investigating external and internal working processes of mining machines when operating on “unclarified” water in underground conditions

Introduction. The article considers the issues of mine drainage study, including the working processes of the centrifugal pumps pumping “unclarified” water in arduous underground conditions. Such problems resolution is of high practical and scientific importance. Methods of research. Scientific and practical experience in the field of mine drainage was analyzed and generalized. The centrifugal pump modes were considered and promising research tasks in this field were outlined. Thus, the continuous income of groundwater to mine workings requires the uninterrupted operation of pumps. One of the most common types of mine-drainage plants is a multistage centrifugal pump which fulfills its functions to the full if properly operated. However, “unclarified” water pumping requires a new technique for centrifugal pump optimal modes determination in such service conditions. Result and analysis. The study of hydraulic, volumetric, and mechanical efficiency dependency on pump modes, the analysis of working processes within centrifugal pumps when operating on “unclarified” water, and the procedure and calculation of TsNS (multistage centrifugal pump) head-capacity curve were presented in the paper to justify the effectiveness of the presented solutions and conclusions. Scope of results. It is recommended that the research results are introduced in all enterprises conducting underground mining operations with the mine drainage.

Pengujian Kinerja Pompa Sentrifugal Multistage Berkapasitas 118,5 KW pada PLTP Berdasarakan Standar ISO 9906

AbstrakPengujian unjuk kerja pompa sentrifugal multistage berkapasitas 118,5 kW di kawasan Pembangkit Listrik Tenaga Panas Bumi (PLTP) daerah Jawa Barat saat ini akan menyesuaikan prosedur standar. Standar pengujian pompa diterapkan pada proses pengujian pompa dengan tujuan nilai hasil pengujian valid. Nilai head dan debit yang didapat dari pengujian dibandingkan dengan hasil pengujian sebelum penerapan standar. Pengujian pompa sentrifugal menerapkan metode pengujian lapangan dengan menerapkan standar ISO 9906-2012. Standar ISO 9906-2012 adalah panduan baku pengujian pompa rotodinamik. Dari hasil pengujian, didapatkan kurva pompa sentrifugal multistage debit maksimal 116,64 m3/h pada head 275,13 m. Pada data spesifikasi kapasitas pompa sebesar 108 m3/jam dan head total sebesar 300 m. Hal ini berarti prosedur pengujian pompa ISO 9906-2012 dapat memungkinkan kita untuk melihat kinerja pompa aktual.Kata kunci: pompa sentrifugal, pengujian lapangan, uji kinerja pompa, ISO 9906 AbstractPerformance test of multistage centrifugal pump at geothermal power plant area around west java is about to adapt standard procedure. Pump testing standards are applied during pump performance test in order to valid test result values. Head and flowrate value from current test compared with previous test result before standard are applied. Pump performance test use field test method by applying ISO 9906-2012 standard. ISO 9906-2012 standard is a normative guidance for rotodynamic pump testing. The test result shows multistage centrifugal pump curve maximum flowrate is 116,64 m3/h at total head 275,13 m. Pump specification sheet shows that maximum capacity is 108 m3/h and total head 300 m. It indicates that ISO 9906-2012 standard pump testing procedure allow us to determine actual pump performance.Kata kunci: Centrifugal pump, field test, performance test, ISO 9906

Nature-Inspired Modified Bat Algorithm for the High-Efficiency Optimization of a Multistage Centrifugal Pump for a Reverse Osmosis Desalination System

The high-pressure multistage centrifugal pump is the main piece of energy-consuming equipment in the reverse osmosis desalination process, and it consumes about 35% of the entire system’s operating cost. The optimization process of multi-stage pumps undoubtedly requires the performance comparison of multiple schemes in order to verify the effectiveness of the optimized design and the optimization method. Therefore, based on ANSYS Workbench and an improved bat algorithm, an intelligent optimization scheme was designed and carried out on a three-stage reverse osmosis desalination high-pressure pump for efficiency improvement by optimizing the matching relationship between the impeller and the guide vane. An external characteristic test was carried out in an open test rig system in order to verify the numerical model. After modifying the positive guide vane structure, the efficiency was improved for both the rated design and the non-design flow conditions without obvious separation and backflow. With the improved bat algorithm, there was a 3.98% increase in the design point efficiency after the final optimization. Under the design conditions, all of the large vortices disappeared after the optimization. The study provides a reference for the optimization design of the impeller–guide vane matching effect in a multistage pump using an improved bat algorithm.

Analysis of unsteady flow and fluid exciting forces of multistage centrifugal pump based on actual size

The unsteady flow and fluid exciting force inside the multistage centrifugal pump were analyzed on the basis of large eddy simulation (LES). The reliability of the numerical simulation was verified by the experimental performance. The performance of pump calculated was closer to the experimental one than that by the Reynolds time average turbulence model, and the errors were 0.36% and 1.14% at the design flow rate, respectively. The results showed that the different distribution and magnitude of the inlet velocity at each stage impeller contributed to the difference of the head for each one. With the increase of flow rates from 0.4Q to 1.2Q, the rule of axial forces for each stage was roughly the same but the total axial force increased from 25.02kN to 29.92kN. The radial force in the Z direction was smaller than the one in the Y direction, and the amplitude of the main frequency in the Z direction changed more gently for the double tongue. Adopting back-to-back impeller distributions can effectively reduce the axial force. The symmetric distributed double tongue can reduce the radial force and play a key role in reducing the vibration of the centrifugal pump.

Effect of an Inducer-Type Guide Vane on Hydraulic Losses at the Inter-Stage Flow Passage of a Multistage Centrifugal Pump

A multistage centrifugal pump was developed for high head and high flow rate applications. A double-suction impeller and a twin-volute were installed at the first stage followed by an impeller, diffuser and return vanes for the next four stages. An initial design feasibility study was conducted using three-dimensional computational fluid dynamics tools to study the performance and the hydraulic losses associated with the design. Substantial losses in head and efficiency were observed at the interface between the first stage volute and the second stage impeller. An inducer-type guide vane (ITGV) was installed at this location to mitigate the losses by reducing the circumferential velocity of the fluid exiting the volute. The ITGV regulated the pre-swirl of the fluid entering the second stage impeller. The pump with and without ITGV is compared at the design flow rate. The pump with ITGV increased the stage head by 63.28% and stage efficiency by 47.17% at the second stage. As a result, the overall performance of the pump increased by 5.78% and 3.94% in head and efficiency, respectively, at the design point. The ITGV has a significant impact on decreasing losses at both design and off-design conditions. An in-depth flow dynamic analysis at the inducer-impeller interface is also presented.

Flow Field Analysis and Feasibility Study of a Multistage Centrifugal Pump Designed for Low-Viscous Fluids

A multistage centrifugal pump is designed for pumping low-viscosity, highly volatile and flammable chemicals, including hydrocarbons, for high head requirements. The five-stage centrifugal pump consists of a double-suction impeller at the first stage followed by a twin volute. The impellers for stages two through five are single-suction impellers followed by diffuser vanes and return channel vanes. The analytical performance is calculated initially in the design stage by applying similarity laws to an existing scaled-down pump model designed for low flow rate applications. The proposed pump design is investigated using computational fluid dynamics tools to study its performance in design and off-design conditions for water as the base fluid. The design feasibility of the centrifugal pump is tested for other fluids, such as water at a high temperature and pressure, diesel and debutanized diesel. The pump design is found to be suitable for a variety of fluids and operating ranges. The losses in the pump are analyzed in each stage at the best efficiency point. The losses in efficiency and head are observed to be higher in the second stage than in other stages. The detailed flow behavior at the second stage is studied to identify the root cause of the losses. Design modifications are recommended to diminish the losses and improve the overall performance of the pump.