Pulp pumping efficiency II – Designing of a pulp pump

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Qihua Zhang ◽  
Shun Kang ◽  
Zhiang Xie ◽  
Li Cao ◽  
Zhaoxu Yan ◽  
...  
Keyword(s):  
Optimization Procedure ◽  
Tip Clearance ◽  
Impeller Blade ◽  
Pumping System ◽  
Pumping Efficiency ◽  
Erosion Corrosion ◽  
Efficiency Increase ◽  
Set Up ◽  
Designing Method ◽  
Optimal Designing

Abstract Based on the loss model of pulp pump set up in the I part of this research, an efficient designing method is proposed by taking account of the influences of head reduction by small blade number, leakage loss via tip clearance, and erosion-corrosion wears in pumps separately. Further, a two-stage optimal designing approach was proposed to tackle the oversized design. The pump designing was performed by coupling with a CFD-based optimization procedure. An efficiency increase of near 10 % was achieved on the pump model validated in laboratory. It was proved that performance could be improved by increasing the impeller blade width and enlarging the impeller blade outlet angle. It was further shown that the erosion-corrosion wear in pulp pump was relatively lighter when compared to particle-impingement wear in slurry and sewage pump. Adoption of composite material showed potential in energy-saving in the pumping system.

Experimental Investigation on Anti-Fatigue Function of Gear Surface with Grid Micro-Morphology

2013 ◽  
Vol 652-654 ◽  
pp. 1842-1845
Author(s):  
Li Yan Wu ◽  
You Lv ◽  
Yu Qiu Song ◽  
Yue Feng Cui ◽  
Wen Tao Ren
Keyword(s):  
Experimental Investigation ◽  
Fatigue Tests ◽  
Laser Engraving ◽  
Gear Teeth ◽  
Bionic Surface ◽  
Fatigue Characteristics ◽  
Set Up ◽  
Micro Morphology ◽  
Designing Method ◽  
Optimal Designing

Based on the experimental optimal designing method, the experimental plan was set up. In order to study anti-fatigue capability of the gear, the laser engraving technology was applied to process the grid type bionic micro-morphology texture on the gear teeth surface. Different anti-fatigue characteristics of the bionic samples were obtained through analyzing the fatigue tests results. The results showed that the pitting ratio of the gear specimens with the grid micro-morphology had been decreased obviously. The grid bionic surface micro-morphology on the gear had improved the anti-fatigue capability of the gear to 139%, and mechanism of anti-fatigue of the bionic gear was ascribed to “Dam Effect”, laser strengthen and changing of lubrication.

Pulp pumping efficiency I – A critical review on loss and its estimation

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Qihua Zhang ◽  
Shun Kang ◽  
Zhiang Xie ◽  
Li Cao ◽  
Zhaoxu Yan ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Paper Industry ◽  
Pulp And Paper Industry ◽  
Pulp And Paper ◽  
Efficiency Improvement ◽  
Pumping System ◽  
Factors Influencing ◽  
Pumping Efficiency ◽  
Low Efficiency ◽  
Set Up

Abstract With growing demand of paper products, the electric consumption in pulp and paper industry is increasing globally where a share of 30 % is attributed to the pulp pumping system. The efficient designing and running of pumping system are critical for energy efficiency. The incomplete information on pulp flows and the oversized designs are the major causes of low efficiency. In the first part of this research, the fiber level models and rheological properties covering a series of unit applications are examined. A loss model of pulp pump is set up by considering different factors influencing pumping performance. The efficiency improvement opportunities in pulp pumping are systematically investigated. The drag-reducing feature at low consistency pulp pumping is highlighted which will be further applied in energy optimized sizing and dimensioning of a pulp pump in the second part of this research.

scholarly journals A Selective Solar Absorber for Unconcentrated Solar Thermal Panels

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 900
Author(s):  
Davide De Maio ◽  
Carmine D’Alessandro ◽  
Antonio Caldarelli ◽  
Daniela De Luca ◽  
Emiliano Di Gennaro ◽  
...  
Keyword(s):  
Fossil Fuels ◽  
High Vacuum ◽  
Optimization Procedure ◽  
Energy Transition ◽  
Spectral Emissivity ◽  
Thermal Conversion ◽  
Stagnation Temperature ◽  
Solar Absorber ◽  
Analytical Formulas ◽  
Set Up

A new Selective Solar Absorber, designed to improve the Sun-to-thermal conversion efficiency at mid temperatures in high vacuum flat thermal collectors, is presented. Efficiency has been evaluated by using analytical formulas and a numerical thermal model. Both results have been experimentally validated using a commercial absorber in a custom experimental set-up. The optimization procedure aimed at obtaining Selective Solar Absorber is presented and discussed in the case of a metal dielectric multilayer based on Cr2O3 and Ti. The importance of adopting a real spectral emissivity curve to estimate high thermal efficiency at high temperatures in a selective solar absorber is outlined. Optimized absorber multilayers can be 10% more efficient than the commercial alternative at 250 °C operating temperatures, reaching 400 °C stagnation temperature without Sun concentration confirming that high vacuum flat thermal collectors can give important contribution to the energy transition from fossil fuels to renewable energy for efficient heat production.

The Parametric Modeling and Contact Strength Analysis for the Wind Power Increasing Gear

2012 ◽  
Vol 522 ◽  
pp. 447-452
Author(s):  
Jing Luo ◽  
Mutellip Ahmat ◽  
Qiang Gao ◽  
Li Chao Ren
Keyword(s):  
Wind Power ◽  
Theoretical Basis ◽  
Optimization Design ◽  
3D Model ◽  
Parametric Modeling ◽  
Strength Analysis ◽  
Contact Strength ◽  
Set Up ◽  
Gear Contact ◽  
Designing Method

In this paper, the precise 3D model of the wind power increasing gear was set up by based on the parametric designing method of Pro/Program, then the contact strength of the gear was analyzed by the FEM and the Hertz theoretical value was calculated, the FEM and the Hertz results were contrasted in order to confirm the applicability of the numerical analysis in wind power gear contact analysis. Finally, the corresponding analysis conclusion was received.The researching results offered a effective theoretical basis for the optimization design and analysis of the wind increasing gear.

A Method for the Calculation of the Tip Clearance Flow Effects in Axial Flow Compressors: Part II — Calculation Procedure

1993 ◽  
Author(s):  
I. K. Nikolos ◽  
D. I. Douvikas ◽  
K. D. Papailiou
Keyword(s):  
Axial Flow ◽  
Tip Clearance ◽  
Tip Clearance Flow ◽  
Vorticity Distribution ◽  
Clearance Flow ◽  
Calculation Results ◽  
Flow Effects ◽  
Set Up ◽  
Induced Velocity ◽  
Theoretical Procedure

An algorithm was set up for the implementation of the tip clearance models, described in Part I, in a secondary flow calculation method. A complete theoretical procedure was, thus, developed, which calculates the circumferentially averaged flow quantities and their radial variation due to the tip clearance effects. The calculation takes place in successive planes, where a Poisson equation is solved in order to provide the kinematic field. The self induced velocity is used for the positioning of the leakage vortex and a diffusion model is adopted for the vorticity distribution. The calculated pressure deficit due to the vortex presence is used, through an iterative procedure, in order to modify the pressure difference in the tip region. The method of implementation and the corresponding algorithm are described in this part of the paper and calculation results are compared to experimental ones for cascades and single rotors. The agreement between theory and experiment is good.

Velocity characteristics in a multiphase pump under different tip clearances

2020 ◽  
pp. 095765092094653
Author(s):  
Guangtai Shi ◽  
Zongku Liu ◽  
Yexiang Xiao ◽  
Helin Li ◽  
Xiaobing Liu
Keyword(s):  
Velocity Distribution ◽  
Flow Rate ◽  
High Speed ◽  
Stokes Equations ◽  
Design Flow ◽  
Tip Clearance ◽  
High Speed Photography ◽  
Hydraulic Loss ◽  
Impeller Blade ◽  
Multiphase Pump

To investigate the effect of tip clearance on the velocity distribution in a multiphase pump, the internal flow and velocity distribution characteristics in pump under different tip clearances are studied using experimental and numerical methods. Simulations based on the Reynolds-Averaged Navier-Stokes equations (RANS) and the standard k-ε turbulence model are carried out using ANSYS CFX. Under conditions of inlet gas void fraction (IGVF) is 5% at the flow rate of 0.6Q, 0.7Q and 0.8Q (Q is the design flow rate), the accuracy of the numerical method is verified by comparing with the experimental data using high-speed photography. Results show that the leakage flow interacts with the main flow and evolves into the tip leakage vortex (TLV). Due to the TLV, the pressure, velocity, turbulent kinetic energy (TKE), vorticity and streamlines on the S2 stream surface in the impeller and diffuser are changed greatly under different tip clearances. The velocities at the impeller outlet and diffuser inlet along the radial direction are also changed. The axial velocity distribution is similar to the meridional velocity distribution at the impeller blade outlet. While the relative velocity and absolute velocity distribution show the opposite trends. In addition, the vorticity is larger near the tip separated vortex and the hydraulic loss in pump is also increased due to the TLV.

scholarly journals Analysis of impeller blade parameters and tip clearance of turboexpander in organic Rankine cycle system

2019 ◽  
Vol 7 (6) ◽  
pp. 3283-3296
Author(s):  
Wenguang Jia ◽  
Chuanwei Wang ◽  
Kerui Zhang ◽  
Shaohua Feng ◽  
Jinglu Yan ◽  
...  
Keyword(s):  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Tip Clearance ◽  
Impeller Blade ◽  
Cycle System

An Automatic Designing Method for Apparel

2011 ◽  
Vol 88-89 ◽  
pp. 175-179
Author(s):  
Xiao Gang Wang ◽  
Qin Zheng ◽  
Xin Zhan Li
Keyword(s):  
Point Cloud ◽  
Science Research ◽  
Mathematic Model ◽  
New Method ◽  
Scanning System ◽  
Body Scanning ◽  
3D Shape ◽  
Vertical Sections ◽  
Set Up ◽  
Designing Method

In this article we discuss a new method for describing the 3D shape of woman warm jacket and set up its mathematic model, which is by dint of body scanning technology. Telmat scanning system scanned samples. The scanning point cloud were analyzed in horizontal and vertical sections. Outlines of vertical sections were described and mathematic models were set up. The result helped to prognosticate the shape of woman warm jacket. A new describing method for 3D shape is discussed. And it opens our mind to utilize body-scanning technology for deeper science research.

Performance evaluation of the inter-stage labyrinth seal for different tooth positions in an axial compressor

2017 ◽  
Vol 232 (6) ◽  
pp. 579-592 ◽  
Author(s):  
Xiaozhi Kong ◽  
Gaowen Liu ◽  
Yuxin Liu ◽  
Zhao Lei ◽  
Longxi Zheng
Keyword(s):  
Axial Compressor ◽  
Labyrinth Seal ◽  
Tip Clearance ◽  
Test Facility ◽  
Leakage Flow ◽  
Rotating Disc ◽  
Labyrinth Seals ◽  
Leakage Flows ◽  
Sealing Performance ◽  
Set Up

Labyrinth seals are normally used to control the leakage flow in the compressor stator well. The upstream and downstream rotor-stator cavities of the labyrinth seal can cause complex reverse leakage flows. Remarkable temperature increases and high swirl velocities are observed in this region. In addition, another characteristic of inter-stage labyrinth seal is that large expansions of rotor and stator may easily lead to severely rubbing between the teeth and shrouds, which can shorten the lifetime of the compressor obviously. Experiments were conducted at a rotating compressor inter-stage seal test facility. Different labyrinth rings were tested to compare the performances of inter-stage labyrinth seals with different tooth positions. Leakage flow rates, windage heating and swirl ratios in the outlet cavity were measured at different rotating speeds and pressure ratios. In order to get the working tip clearance accurately, the set up tip clearance was measured with plug gauges, while the radial displacements of rotating disc and stationary casing were measured separately with two high precision laser distance sensors. Numerical simulations were carried out to present the important flow physics responsible for the effects of different tooth positions. In this article, performances of different cases for single, double and triple teeth were investigated and the experimental data provide a new way for the design of inter-stage seals. This method can reduce the leakage flow and avoid severely rubbing at the same time by changing axial positions of teeth in the stator well. When teeth are placed downstream of the model and the tooth pitch is larger, the inter-stage seal would have better sealing performance. For triple teeth cases, N = 3-Case1 has the lowest discharge coefficients, 15% less than that of N = 3-Baseline.

Glider fuselage-wing junction optimization using CFD and RBF mesh morphing

2016 ◽  
Vol 88 (6) ◽  
pp. 740-752 ◽  
Author(s):  
Marco Evangelos Biancolini ◽  
Emiliano Costa ◽  
Ubaldo Cella ◽  
Corrado Groth ◽  
Gregor Veble ◽  
...  
Keyword(s):  
High Performance ◽  
Optimization Procedure ◽  
Local Geometry ◽  
Mathematical Framework ◽  
Aerodynamic Efficiency ◽  
Content Type ◽  
Mesh Morphing ◽  
Design Variables ◽  
Optimization Study ◽  
Set Up

Purpose The present paper aims to address the description of a numerical optimization procedure, based on mesh morphing, and its application for the improvement of the aerodynamic performance of an industrial glider which suffers of a large separation occurring in the wing–fuselage junction region at high incidence angles. Design/methodology/approach Shape variations were applied to the baseline configuration through a mesh morphing technique founded on the mathematical framework of radial basis functions (RBF). The aerodynamic solutions were obtained coupling an RANS code with the mesh morphing tool RBF Morph™. Two shape modifiers were set up to generate a parametric numerical model. An optimization procedure, based on a design of experiment sampling, was set up implementing the fully automated workflow within a high performance computing (HPC) environment. The optimal candidates maximizing the aerodynamic efficiency were identified by means of a cubic RBF response surface approach. Findings The separation was significantly reduced, modifying the local geometry of fuselage and fairing and maintaining the wing aerofoil unchanged. A relevant aerodynamic efficiency improvement was finally gained. Practical implications The developed procedure proved to be a very powerful and efficient tool in facing aerodynamic design problems. However, it might be computationally very expensive if a large number of design variables are adopted and, in those cases, the method can be suitably used only within the HPC environment. Originality/value Such an optimization study is part of an explorative set of analyses that focused on better addressing the numerical strategies to be used in the development of the EU FP7 Project RBF4AERO.

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