Introducing machine learning and hybrid algorithm for prediction and optimization of multistage centrifugal pump in an ORC system

Energy ◽  
2021 ◽  
Vol 222 ◽  
pp. 120007
Author(s):  
Xu Ping ◽  
Fubin Yang ◽  
Hongguang Zhang ◽  
Jian Zhang ◽  
Wujie Zhang ◽  
...  
2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Ling Bai ◽  
Ling Zhou ◽  
Xiaoping Jiang ◽  
Qinglong Pang ◽  
Daoxing Ye

Multistage pumps are intended to improve designs with low-vibration and -noise features as the industry applications increase the technical requirements. In this frame, it becomes really important to fully understand the vibration patterns of these kinds of complex machines. In this study, a vibration test bench was established to examine the vibration and stability of a cantilever multistage centrifugal pump under different flow rates. The vibration spectrum diagrams for the inlet and outlet sections and the pump body were evaluated under varied flow conditions. Results showed the effects of operational conditions on the vibration of the cantilever multistage centrifugal pump. Vibration velocity was primarily caused by mass unbalance at the shut-off flow rate point. Under different flow conditions, the blade passing frequency (BPF) and two times the blade passing frequency (2BPF) were the main excitation frequencies. The vibration frequency of the final pump body remained at the BPF under different flow conditions due to the contact with the outlet section. The major type of vibration frequency for the inlet and outlet was high frequency.


2019 ◽  
Vol 11 (12) ◽  
pp. 168781401989783
Author(s):  
Yun Ren ◽  
Zuchao Zhu ◽  
Denghao Wu ◽  
Xiaojun Li ◽  
Lanfang Jiang

The mechanism of flow separation in the impeller of a centrifugal pump with a low specific speed was explored by experimental, numerical, and theoretical methods. A novel delayed Reynolds-averaged Navier–Stokes/large eddy simulation hybrid algorithm combined with a rotation and curvature correction method was developed to calculate the inner flow field of the original pump for the large friction loss in the centrifugal impeller, high adverse pressure gradient, and large blade curvature. Boundary vorticity flux theory was introduced for internal flow diagnosis, and the relative velocity vector near the surface of the blade and the distribution of the dimensionless pressure coefficient was analyzed. The validity of the numerical method was verified, and the location of the backflow area and its flow features were determined. Finally, based on flow diagnosis, the geometric parameters influencing the flow state of the impeller were specifically adjusted to obtain a new design impeller. The results showed that the distribution of the boundary vorticity flux peak values, the skin friction streamline, and near-wall relative velocities improved significantly after the design change. In addition, the flow separation was delayed, the force applied on the blade was improved, the head under the part-load condition was improved, and the hydraulic efficiency was improved over the global flow ranges. It was demonstrated that the delayed Reynolds-averaged Navier–Stokes/large eddy simulation hybrid algorithm was capable to capture the separation flow in a centrifugal pump, and the boundary vorticity flux theory was suitable for the internal flow diagnosis of centrifugal pump.


Author(s):  
Laxman Y. Waghmode ◽  
Ravindra S. Birajdar ◽  
Shridhar G. Joshi

It is well known that the pumps are the largest consumers of industrial motor energy and account for more than 25% of electricity consumption. The life cycle cost of a pump is the total lifetime cost associated with procurement, installation, operation, maintenance and its disposal. For majority of heavy usage pumps, the lifetime energy and/or maintenance cost will dominate the life cycle costs. Hence a greater understanding of all the cost components making up the total life cycle costs should provide an opportunity to achieve a substantial savings in energy and maintenance costs. This will further enable optimizing pumping system efficiency and improving pump and system reliability. Therefore in this context, the life cycle cost analysis of heavy usage pumps is quite important. This paper focuses on an application of a methodology of determining the life cycle cost of a typical heavy usage multistage centrifugal pump. In this case, all the cost components associated with the pump-set have been determined and classified under different categories. The data with regard to initial investment costs, operation costs, maintenance and repair costs and disposal costs for the pump considered for this case study was collected from the concerned pump manufacturer along with the unit cost of each component, quantity used and their weights. By applying the principles of reliability and maintainability engineering and using the data obtained from the design, manufacturing and maintenance departments, the component-wise values of MTBF (Mean Time Between Failures) and MTTR (Mean Time To Repair) were estimated. The results of the life cycle cost analysis of the specimen pump were compared with the life cycle costs of similar pumps reported in the literature. From this comparison of results, it can be concluded that, the initial cost of the pump is the only a fraction of the total life cycle cost. The operating cost of the pump dominates the life cycle costs especially in case of heavy usage pumps. The maintenance cost varies approximately from 0.6 to 2.5 times the initial cost of the pump. The life cycle cost of the pump varies approximately from 12 to 33 times the initial cost of the pump. The operation and maintenance cost is almost 92 to 97 per cent of the life cycle cost. The detailed analysis carried out in this paper is expected to provide guidelines to the pump manufactures/practicing engineers in selecting a heavy usage multistage centrifugal pump based on the total lifetime cost rather than only on initial price.


2015 ◽  
Vol 18 (1) ◽  
pp. 65-71 ◽  
Author(s):  
Rakibuzzaman Rakibuzzaman ◽  
Sang-Ho Suh ◽  
Hyoung-Ho Kim ◽  
Min-Tae Cho ◽  
Byeong-Rog Shin

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