scholarly journals Vibration Test and Shock Absorption of Coal Crusher Chambers in Thermal Power Plants (II): Numerical Analysis

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Hanquan Yuan ◽  
Lihua Zhu ◽  
Haoyi Zhou ◽  
Dong Jiang ◽  
Baoquan Liu ◽  
...  
Keyword(s):  
Power Plants ◽  
Vibration Isolation ◽  
Design Method ◽  
Thermal Power ◽  
Element Model ◽  
Dynamic Coefficient ◽  
Test Results ◽  
Vibration Isolator ◽  
Shock Absorption ◽  
Vibration Displacement

The coal crusher generates large vibrations when crushing coal blocks, which can affect the equipment itself, as well as the safety of the structure. In order to study the dynamic characteristics of coal crusher, a finite element model of the coal crusher chamber in the Shangluo power plant was built by using ABAQUS. Firstly, modal and harmonic response analyses were conducted, and the comparison shows that the numerical results are basically in accordance with the test results. Then, shock absorption research was performed using a parametric analysis that included the stiffness and position of the spring vibration isolator, the mass, and material of the vibration-isolation platform. Finally, the dynamic coefficient of a coal crusher was discussed. The results showed that, compared with the stiffness of the spring vibration isolator, the mass of the vibration-isolation platform had more influence on the vibration displacement of the coal crusher. To achieve better vibration isolation, the concrete platform is suggested, and the eccentricity of the spring vibration isolator should not exceed 5%. When static design method is adopted to calculate the bearing capacity of the supporting structure subjected to the dynamic load of the coal crusher, the dynamic coefficient of a coal crusher is suggested as 1.5.

scholarly journals Vibration Test and Shock Absorption of Coal Crusher Chambers in Thermal Power Plants (I): Field Test and Assessment

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Lihua Zhu ◽  
Hanquan Yuan ◽  
Haoyi Zhou ◽  
Dong Jiang ◽  
Baoquan Liu ◽  
...  
Keyword(s):  
Power Plants ◽  
Vibration Isolation ◽  
Thermal Power ◽  
Vibration Test ◽  
Thermal Power Plants ◽  
Test Results ◽  
Vibration Displacement ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Vibration Performance

A field vibration test was conducted on the coal crusher chamber of a thermal power plant to evaluate its vibration performance. The vibration displacements and velocities of the structure, coal crusher body, and vibration-isolation platform were tested. The vibration safety of the coal crusher chamber and the vibration-isolation efficiency of the spring vibration-isolation system were evaluated based on the test results, and the reason the vibration exceeded the limit was analyzed. This study showed that the vibration displacement of a coal crusher with a spring vibration-isolation system met the code requirements, but the equipment had greater vibration displacements, which were related to the connection between the equipment and the platform. Compared to a steel platform, the vibration displacement of a concrete platform was smaller, and the vibration-isolation efficiency was greater. The vibration displacements of the coal crusher body could be reduced by controlling the vibration displacements of the platform.

Vibration Test and Analysis on Medium-Speed Mill-Foundation Coupled System

2012 ◽  
Vol 166-169 ◽  
pp. 530-533
Author(s):  
Bin Xu ◽  
Zhi Feng Peng ◽  
Fang Liu ◽  
Yi Liang Peng ◽  
Feng Jian Zhang
Keyword(s):  
Power Plants ◽  
Thermal Power ◽  
Coupled System ◽  
Vibration Test ◽  
Thermal Power Plants ◽  
Test Results ◽  
Vibration Displacement ◽  
Medium Speed ◽  
Vibration Performance

To evaluate the vibration performance of medium-speed mill-foundation coupled system, eight mills in five thermal power plants were tested in site. The vibration displacement and acceleration of upper and lower bedplates of foundations and equipment bodies were measured. According to the test results, the vibration safety of mills is evaluated. The study shows that the vibration displacement of medium-speed mill with spring vibration-isolated foundation meets the code requirements, but the vibration displacement of equipment body is larger. The vibration displacement of equipment body should be controlled by limiting the vibration displacement of foundation platform in design.

scholarly journals CORROSION BEHAVIOUR OF ALUMINIUM 6061 NICKEL COATED CENOSPHERE COMPOSITE

2020 ◽  
Vol 15 (3) ◽  
Author(s):  
Arvind R S ◽  
Prasanna Ram M ◽  
Prashanth T ◽  
Jaimon Dennis Quadros
Keyword(s):  
Coal Combustion ◽  
Metal Matrix ◽  
Power Plants ◽  
Corrosion Behaviour ◽  
Thermal Power ◽  
Stir Casting ◽  
Matrix Composites ◽  
Test Results ◽  
Immersion Corrosion ◽  
Aluminium Metal

Cenosphere fly ash is one of the most inexpensive and low-density material which is abundantly available as a solid waste by-product of coal combustion in thermal power plants. Aluminium metal matrix composites with Nickel coated cenospheres as the reinforcement is prepared by stir casting route. The composites are prepared with varying percentages of cenospheres in the percentage of 2-10% by weight of the composite. Immersion corrosion tests are conducted on the composites in three different medium and for three different time durations. It is evident from the test results as well as the microstructure images that the weight loss of samples with 8% Nickel coated cenospheres has shown least corrosion or the highest corrosion resistance when compared to the counterparts.

Research and Development of Viscous Fluid Dampers for Improvement of Seismic Resistance of Thermal Power Plants: Part 7 — Evaluation of Lifetime Using Experimental Design Method

2019 ◽  
Author(s):  
Kiyoshi Aida ◽  
Keisuke Minagawa ◽  
Go Tanaka ◽  
Satoshi Fujita
Keyword(s):  
Experimental Design ◽  
Viscous Fluid ◽  
Power Plants ◽  
Design Method ◽  
Thermal Power ◽  
Great East Japan Earthquake ◽  
Thermal Power Plants ◽  
Support Structures ◽  
Long Duration ◽  
Experimental Design Method

Abstract In 2011, Great East Japan Earthquake that was the largest earthquake in Japanese history occurred. The earthquake had large acceleration, long duration and a lot of aftershocks, and coal-fired thermal power plants were damaged by the earthquake. Boiler structures in coal-fired thermal power plants are generally high-rise structures, and boilers are simply suspended from the top of the support structures in order not to restrict thermal expansion. Therefore boilers are easy to vibrate. In order to suppress vibration of boilers during earthquakes, stoppers are generally set between boilers and support structures. The stoppers are made of steel, and dissipate vibration energy by plastic deformation. However aseismic requirements for thermal power plants have been increased as a result of the Great East Japan Earthquake. Thus authors have developed a vibration control damper for coal-fired power plants. The damper is set instead of conventional stopper. Construction of the damper is similar to oil dampers, but inner fluid is viscous fluid. In PVP 2017, the basic performance of the proposed damper was presented. In PVP 2018, influence of dispersion of damper properties was also investigated. In addition, seismic response analyses using various earthquakes that include long period and long duration earthquake waves were carried out. As a result of previous investigations, it was confirmed that the proposed damper has good performance in its lifetime. However, parameters of dampers were selected manually. Therefore, influence of parameters of dampers on the lifetime were evaluated theoretically by using the experimental design method in this paper. The experimental design method is one of the effective techniques for research such as investigation of the influence of the habitat environment on the growth of crops. The selection of damper parameters is complex optimization, because so many variables need to be optimized. Therefore the experimental design method is suitable technique for the evaluation of damper parameters. This paper evaluates lifetime of dampers from the viewpoint of the experimental design method.

Design and Experiment of Inerter-Rubber Vibration Isolator Based on Parallel Inerter-Spring-Damper System

2021 ◽  
pp. 1-10
Author(s):  
Huabing Wen ◽  
Wei Liu ◽  
Junhua Guo ◽  
Kun Zhang ◽  
Yang Li ◽  
...  
Keyword(s):  
Vibration Isolation ◽  
Design Method ◽  
Resonant Peak ◽  
Design Parameters ◽  
Vibration Isolator ◽  
Test Bed ◽  
Multi Objective Genetic Algorithm ◽  
Rubber Part ◽  
Practical Engineering ◽  
Engineering Significance

Since an inerter has been widely used in the field of vibration isolation, the combination of the inerter and the rubber part inevitably becomes a trend. In this work, a parallel inerter-spring-damper system (II-ISD) was introduced and analyzed for its performance on vibration isolation. Then, the optimal inertance-mass ratio and the frequency ratio at the minimum transmissibility were obtained. Based on the II-ISD system, an integrated vibration isolator was designed where the rubber part paralleled to the inerter, which was named as the inerter-rubber vibration isolator (IR). Then, its mechanical properties were simulated, and the mathematical model was established by considering the vibration isolation performance and the service life. Afterward, it was optimized by a programmed multi-objective genetic algorithm, and the optimal design parameters of IR were got finally. The experimental prototype of IR was processed, and its performance experiment was performed on the Mechanical Testing System (MTS) test bed. Experimental results show that the theoretical model of IR based on the II-ISD system is accurate; the resonant peak of IR is clearly lower than that of the rubber vibration isolator; the natural frequency decreases obviously. This work provides a design method for the serial product development, which has a practical engineering significance.

Finite Element Analysis on Medium-Speed Mill-Foundation Coupled System

2012 ◽  
Vol 166-169 ◽  
pp. 510-513
Author(s):  
Man Zhi Yang ◽  
Zhi Feng Peng ◽  
Fang Liu ◽  
Yi Liang Peng ◽  
Xiao Ling Sun
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Vibration Isolation ◽  
Coupled System ◽  
Element Model ◽  
Element Analysis ◽  
Vibration Displacement ◽  
Horizontal Vibration ◽  
Vibration Isolators ◽  
Medium Speed

A medium speed mill-foundation coupled finite element model was established using ANSYS. The modal and harmonic responses of medium-speed mill were analyzed. The influence of the number of vibration isolators and the ratio of foundation bedplate to equipment on the vibration of mill was analyzed. The shock absorption measures of medium-speed mills were discussed. To get good vibration isolation effect, the maximum horizontal vibration displacement of medium-speed mill with spring vibration-isolated foundation is suggested as 50 μm, and the ratio of foundation bedplate to equipment as 3.0±0.2.

Test Results of Concrete Thermal Energy Storage for Parabolic Trough Power Plants

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Doerte Laing ◽  
Dorothea Lehmann ◽  
Michael Fiß ◽  
Carsten Bahl
Keyword(s):  
Energy Storage ◽  
Power Plants ◽  
Waste Heat ◽  
Thermal Power ◽  
Test Results ◽  
Storage Material ◽  
Storage Test ◽  
Solid Media ◽  
Media Storage ◽  
Test Module

Efficient energy storage is vital to the success of solar thermal power generation and industrial waste heat recovery. A sensible heat storage system using concrete as the storage material has been developed by the German building company Ed. Züblin AG and the German Aerospace Center (DLR). A major focus was the cost reduction in the heat exchanger and the high temperature concrete storage material. For live tests and further improvements, a 20 m3 solid media storage test module connected to an electrically heated thermal oil loop was built in Stuttgart. The design of the test module and the test results are described in this paper. By the end of November 2008, the second generation solid media storage test module had accumulated five months of operation in the temperature range between 300°C and 400°C and almost 100 thermal cycles with a temperature difference of 40 K. The tests will be continued in 2009.

scholarly journals Experience in multistage steam-driven ejectors

2020 ◽  
Vol 178 ◽  
pp. 01002
Author(s):  
Ilia Murmanskii ◽  
Konstantin Aronson ◽  
Nickolay Zhelonkin ◽  
Alexander Ryabchikov ◽  
Adriano Milazzo ◽  
...  
Keyword(s):  
Power Plants ◽  
Design Method ◽  
Thermal Power ◽  
Geometrical Parameters ◽  
Thermal Power Plants ◽  
Design Solutions ◽  
Improved Design ◽  
Steam Parameters ◽  
Technical Solutions

The article presents some trends of multistage steam-driven ejectors improvement and examples of its implementation. Three relevant directions were picked out: increasing of reliability, profitability and efficiency. Regarding the reliability increasing, existing serial ejector designs of various manufactures were analyzed. A number of new technical solutions were designed. For profitability raising two approaches were considered: decreasing of primary steam parameters and effect of high ejector productivity to the vacuum deviation in the condenser. Efficiency increasing comprises jet devices improvement. For these reasons a design method was refined. In this case geometrical parameters of existing serial ejectors were summarized, CFD research was performed. The improved design method along with new design solutions are implemented in several ejectors successfully. New ejectors are set at thermal power plants and have shown a high technical-economical effect.

Behavior and design method for offset multi-wedges swaged couplers under uniaxial tension

2020 ◽  
pp. 136943322096847
Author(s):  
Zexin Liu ◽  
Peijun Wang ◽  
Yuanjian Liu ◽  
Ying Chen ◽  
Fangzhou Liu
Keyword(s):  
Uniaxial Tension ◽  
Design Method ◽  
Element Model ◽  
Displacement Curve ◽  
Test Results ◽  
Insertion Force ◽  
Steel Rebar ◽  
Steel Bars ◽  
Overlap Ratio ◽  
Steel Rebars

This paper proposed an Offset Multi-Wedges Swaged Couplers (OMWSC) as mechanical connection of steel rebars. The behavior of the connection consisting of two steel rebars connected by one OMWSC under uniaxial tension is investigated by Finite Element Model (FEM) simulations, which is verified through test results by considering the load-displacement curve, the failure mode and the failure deformation, and the insertion force to install the wedges. Parameter studies are carried out using the verified FEM. Studied parameters included the rebar surface type, the wedge diameter, the steel rebar diameter, the overlap ratio of the wedges that is defined as the ratio of wedge distance to the effective wedge distance, the extrusion ratio that is defined as a half of the wedge diameter to the gap of the two rebars, and the edge distance. Design equations for the coupler and the wedge of an OMWSC are proposed. Verification of the proposed design methods proved the OMWSC designed using the proposed method would not fail prior to the failure of steel bars.

scholarly journals Analysis of Modal and Vibration Reduction of an Interior Permanent Magnet Synchronous Motor

Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3427 ◽  
Author(s):  
Xie ◽  
Xia ◽  
Li ◽  
Li
Keyword(s):  
Permanent Magnet ◽  
Electromagnetic Force ◽  
Optimization Design ◽  
Design Method ◽  
Permanent Magnet Synchronous Motor ◽  
Load Condition ◽  
Element Model ◽  
Permanent Magnet Synchronous Motors ◽  
Vibration Displacement ◽  
Interior Permanent Magnet

Interior permanent magnet synchronous motors (IPMSMs) have been widely used in a variety of applications. The IPMSM will generate vibration as well as functioning like other traditional motors, which will affect the performance and the durability of the motor itself. The modal and vibration characteristics of the IPMSM and an optimization design to reduce vibration are researched in this paper. The formulas of electromagnetic force are deduced and analyzed, and a finite element model is established. The model is used for modal calculation, and the low order natural frequency is obtained. Then, the modal test is carried out by the hammering method, and the resonance frequency is found by analyzing the results. Eventually, the electromagnetic vibration is analyzed by taking the electromagnetic force as the load condition, the vibration displacement waveform is obtained, and the correctness of the dynamic calculation is verified by vibration tests. In addition, an eccentric tooth edge design is proposed to weaken the dominant radial electromagnetic force and the vibration displacement is compared with the designed prototype. This design method, which could help to reduce the vibration and noise of the IPMSM, has great potential in future applications.

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