Numerical Simulation and Performance Prediction of Reversible Submersible Tubular Pumping System

Author(s):  
Yan Jin ◽  
Chao Liu ◽  
Jiren Zhou ◽  
Hua Yang ◽  
Li Cheng

Submersible tubular pump is a kind of horizontal pump with low head and large discharge, which uses the structure of postpositive tubular type with motor and pump coaxial. Nowadays, more and more urban pumping stations need to have the function of irrigation and drainage. In the plain areas, the head of many pumping stations are very low, even only about one meter. Considering the efficiency and practicability, the reversible submersible tubular pump is chosen to realize the function of irrigation and drainage. Research on three-dimensional flow field in a submersible tubular pumping system using numerical simulation based on the Reynolds time-averaged Navier-Stokes equations and the RNG k-ε turbulent model. By using this method, the performance of pumping system such as head, shaft power and efficiency are predicted based on the calculation of different operating conditions. For verifying the accuracy and reliability of the calculation results, a model test was conducted. The comparison of simulation results and the experiment data shown that the calculation performances close agreement with the experiment results in the high efficiency area, but in the condition of large discharge and small discharge, deviations were existed between the two results. Combining with the numerical simulation and experimental, which can provide more evidences for the hydraulic performance prediction and optimization design of pumping system.

Author(s):  
Yan Jin ◽  
Chao Liu ◽  
Li Cheng

Research on three-dimensional flow field in a tubular pumping system using numerical simulation based on the Reynolds time-averaged Navier-Stokes equations and the RNG k–ε turbulent model. By using this method, the performance of pumping system such as head, shaft power and efficiency are predicted based on the calculation of different operating conditions in the discharge range from 20L/s to 35L/s at the same rotating speed. For verifying the accuracy and reliability of the calculation results, a tubular pumping system bedstand is designed for the permarmance test. The comparison of simulation results and the experiment data shown that the calculation performances close agreement with the experiment results in the high efficiency area, but in the condition of large discharge and low discharge, deviations were existed between the two results. Combining with the results of numerical simulation and experiment, which can provide more evidences for the hydraulic performances prediction and optimization design of pumping system.


Author(s):  
Yan Jin ◽  
Chao Liu ◽  
Jiren Zhou ◽  
Fangping Tang

Submersible tubular pump is particularly suitable for ultra-low head (net head less than 2 m) pumping station which can reduce the excavation depth, lower engine room height, simplify hydraulic structure, and save civil engineering costs. Submersible tubular pump with smaller motor unit can reduce the flow resistance. The flow field inside the submersible tubular pump is simulated in a commercial computation fluid dynamics (CFD) code FLUENT. The RNG k-ε turbulent model and SIMPLE algorithm are applied to analyze the full passage of a submersible tubular pump, the performance of pump such as head, shaft power and efficiency are predicted based on the calculation of different operating conditions. The simulations are carried out over a wide range of operating points, from 0.8 of the reference mass flow rate at the best efficiency point (BEP) to the 1.28 of the BEP flow rate at the same rotating speed. For verifying the accuracy and reliability of the calculation results, a model test is conducted. The comparison of simulation results and the experiment data show that the calculation performances are agree with the experiment results in the high efficiency area and large discharge condition, but in the condition of low discharge, it exists deviations between the two results. Compare with the numerical simulation and experiment, which can provide more evidences for the hydraulic performance prediction and optimization design of submersible tubular pump pumping system.


2012 ◽  
Vol 134 (7) ◽  
Author(s):  
Ling Zhou ◽  
Weidong Shi ◽  
Weigang Lu ◽  
Bo Hu ◽  
Suqing Wu

In this paper, the design methodology of a new type of three-dimensional surface return diffuser (3DRD) is presented and described in detail. The main goal was to improve the hydrodynamic performance of the deep-well centrifugal pump (DCP). During this study, a two-stage DCP equipped with two different type diffusers was simulated employing the commercial computational fluid dynamics (CFD) software ANYSY-Fluent to solve the Navier-Stokes equations for three-dimensional steady flow. A sensitivity analysis of the numerical model was performed in order to impose appropriate parameters regarding grid elements number and turbulence model. The flow field and the static pressure distribution in the diffusers obtained by numerical simulation were analyzed, and the diffuser efficiency was defined to quantify the pressure conversion capability. The prototype experimental test results were acquired and compared with the data predicted from the numerical simulation, which showed that the performance of the pump with 3DRD is better than that of the traditional cylindrical return diffuser (CRD) under all operating conditions. The efficiency and single-stage head of the pump with 3DRD have been significantly improved compared with the standard DCP of the same class.


Author(s):  
H. X. Liang ◽  
Q. W. Wang ◽  
L. Q. Luo ◽  
Z. P. Feng

Three-dimensional numerical simulation was conducted to investigate the flow field and heat transfer performance of the Cross-Wavy Primary Surface (CWPS) recuperators for microturbines. Using high-effective compact recuperators to achieve high thermal efficiency is one of the key techniques in the development of microturbine in recent years. Recuperators need to have minimum volume and weight, high reliability and durability. Most important of all, they need to have high thermal-effectiveness and low pressure-losses so that the gas turbine system can achieve high thermal performances. These requirements have attracted some research efforts in designing and implementing low-cost and compact recuperators for gas turbine engines recently. One of the promising techniques to achieve this goal is the so-called primary surface channels with small hydraulic dimensions. In this paper, we conducted a three-dimensional numerical study of flow and heat transfer for the Cross-Wavy Primary Surface (CWPS) channels with two different geometries. In the CWPS configurations the secondary flow is created by means of curved and interrupted surfaces, which may disturb the thermal boundary layers and thus improve the thermal performances of the channels. To facilitate comparison, we chose the identical hydraulic diameters for the above four CWPS channels. Since our experiments on real recuperators showed that the Reynolds number ranges from 150 to 500 under the operating conditions, we implemented all the simulations under laminar flow situations. By analyzing the correlations of Nusselt numbers and friction factors vs. Reynolds numbers of the four CWPS channels, we found that the CWPS channels have superior and comprehensive thermal performance with high compactness, i.e., high heat transfer area to volume ratio, indicating excellent commercialized application in the compact recuperators.


Processes ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 949 ◽  
Author(s):  
Yan Jin ◽  
Xiaoke He ◽  
Ye Zhang ◽  
Shanshan Zhou ◽  
Hongcheng Chen ◽  
...  

This paper presents an investigation of external flow characteristics and pressure fluctuation of a submersible tubular pumping system by using a combination of numerical simulation and experimental methods. The steady numerical simulation is used to predicted the hydraulic performance of the pumping system, and the unsteady calculation is adopted to simulate the pressure fluctuation in different components of a submersible tubular pumping system. A test bench for a model test and pressure pulsation measurement is built to validate the numerical simulation. The results show that the performance curves of the calculation and experiment are in agreement with each other, especially in the high efficiency area, and the deviation is minor under small discharge and large discharge conditions. The pressure pulsation distributions of different flow components, such as the impeller outlet, middle of the guide vane, and guide vane outlet and bulb unit, are basically the same as the measurement data. For the monitoring points on the impeller and the wall of the guide vane especially, the main frequency and its amplitude matching degree are higher, while the pressure pulsation values on the wall of the bulb unit are quite different. The blade passing frequency and its multiples are important parameters for analysis of pressure pulsation; the strongest pressure fluctuation intensity appears in the impeller outlet, which is mainly caused by the rotor–stator interaction. The farther the measuring point from the impeller, the less the pressure pulsation is affected by the blade frequency. The frequency amplitudes decrease from the impeller exit to the bulb unit.


2012 ◽  
Vol 562-564 ◽  
pp. 1438-1441
Author(s):  
Li Hua Fu ◽  
Juan Juan Jiang ◽  
Dai Xing Zhang ◽  
Hai Quan Li ◽  
Hua Song ◽  
...  

In this article, the Pro/Engineer virtual prototyping technology is used for three dimensional entity modeling, assembly, and simulation analysis of 1000KN·m large backstop in four design plans to confirm the integrity and assembling of backstop. By using the ANSYS/LS-DYNA software, it makes numerical simulation analysis of the backstop in non-return process, and through the analysis comparison to the simulation result, it obtains the optimization design plan of the 1000KN·m backstop.


2003 ◽  
Vol 125 (2) ◽  
pp. 301-308 ◽  
Author(s):  
Mathieu Helene ◽  
Mihai Arghir ◽  
Jean Frene

The present work investigates the flow in the feeding recess of a hybrid journal bearing. Numerical integration of the complete Navier-Stokes equations was performed with an appropriate turbulence model. Of primary concern is the pressure field on the rotating journal surface that is commonly known as the recess pressure pattern. The goal of the work is to determine the influences of fluid compressibility, operating conditions and recess geometry. Reference parameters selected for this study comprise feeding Reynolds number Rea of 2.105, sliding Reynolds number Rec of 5.103 and recess depth over film thickness ratio e/H of 2.2. Compressibility was considered first. Three values of the axial exit Mach number were selected for computation, namely 0.2, 0.45, and 0.7. As no significant variation was found, the Mach number was fixed at 0.45 in subsequent studies concerning other parameters:     Feeding Reynolds number, Rea       2.104,2.105,4.105     Recess depth, e/H           0, 2.2, 8     Feedhole axis inclination        90°, 135°, 165°     Feedhole location (Figs. 1(a) and 13)   centered, downstream offset. As each parameter is varied, wire mesh plot of pressure and its sectional profiles are examined and effects of varying various parameters are discussed in reference to flow processes as they may affect the support characteristics of the hybrid journal bearing.


Author(s):  
Chao Liu ◽  
Yan Jin ◽  
Jiren Zhou ◽  
Fangping Tang

The two-floor flow passages pumping system with the simple structure is well practical in the Basin of Yangzi River downstream. However, this kind of pumping system has some disadvantages, such as low efficiency, easy to appear submerse vortex in discharge flow passages which causes the unit vibration and does harm to the operating of pump unit. In order to solve these problems, the design scheme with a new curve of diffusing outlet structure and inlet cone put forward, which are used in the renovation of the two-floor flow passages pumping station. With the numerical simulation of the two-floor flow passages pumping system, the flow fields are analyzed, and the external performance curves are obtained. To verify the calculation, a model tests were done using the standard model of pump. The test results are compared with the performance curves of numerical simulation. Good agreement of two results is found in the high efficiency area, which can show the calculation is believable. The new design improves the efficiency of pumping system significantly and eliminates the submerse vortex, also can guarantees the economy and security of operating.


2020 ◽  
Vol 34 (14n16) ◽  
pp. 2040111
Author(s):  
Shu-Ling Tian ◽  
Ying-Ying Shen ◽  
Yao Li ◽  
Hai-Bo Wang ◽  
Sheryar Muhammad ◽  
...  

Plate-fin heat exchangers are widely used in industry at present due to their compact structure and high efficiency. However, there is a problem of flow maldistribution, resulting in poor performance of heat exchangers. The influence of the header configuration on fluid flow distribution is studied by using CFD software FLUENT. The numerical results show that the fluid flow inside the header is seriously uneven. The reliability of the numerical simulation is validated against the published results. They are found to be basically consistent within considerable error. The optimal number of the punch baffle is investigated. Various header configuration with different opening ratios have been studied under the same boundary conditions. The gross flow maldistribution parameter (S) is used to evaluate flow nonuniformity, and the flow maldistribution parameters of different schemes under different Reynolds numbers are listed and compared. The optimal header with minimum flow maldistribution parameter is obtained through the performance analysis of headers. It is found that the flow maldistribution of the improved header is significantly smaller compared with the conventional header. Hence, the efficiency of the heat exchanger is effectively enhanced. The conclusion provides a reference for the optimization design of plate-fin heat exchanger.


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