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Torque and bending moment acting on a flexible shaft agitated by disk turbines in a gas–liquid stirred vessel

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Chinese Journal of Chemical Engineering 2019年第4期27卷 781-793页

作者： Yangyang Liang Zhengming Gao Dai'en Shi Haotian Li Yuyun Bao Ziqi Cai State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical Technology Beijing 100029 China Mechanical Engineering School Yancheng Institute of Technology Yancheng 224051 China

The torque and bending moment acting on a flexible overhung shaft in a gas–liquid stirred vessel agitated by a Rushton turbine and three different curved-blade disk turbines(half circular blades disk turbine, half elliptical blades disk turbine, and parabolic blades disk turbine) were experimentally measured by a customized moment sensor. The results show that the amplitude distribution of torque can be fitted by a symmetric bimodal distribution for disk turbines, and generally the distribution is more dispersive as the blade curvature or the gas flow rate increases. The amplitude distribution of shaft bending moment can be fitted by an asymmetric Weibull distribution for disk turbines. The relative shaft bending moment manifests a "rising-falling-rising" trend over the gas flow number, which is a corporate contribution of the unstable gas–liquid flow around the impeller, the gas cavities behind the blades, and the direct impact of gas on the impeller. And the "falling" stage is greater and lasts wider over the gas flow number for Rushton turbine than for the curved-blade disk turbines.

关键词： Shaft bending moment Torque Disk turbines Gas–liquid flow Fluid structure interaction

Failure Envelopes of Wide-Shallow Composite Bucket Foundation for Offshore Wind turbines in Silty Sand

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Transactions of Tianjin University 2018年第2期24卷 182-190页

作者： Yonggang Liu Yaohua Guo Hongyan Ding Puyang Zhang State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin University School of Civil Engineering Tianjin University

The wide-shallow composite bucket foundation(WSCBF) is a new type of offshore wind power foundation that can be built on land and rapidly installed offshore, there by effectively reducing the construction time and costs of offshore wind power foundation. In this study, the horizontal bearing capacity is calculated by finite element simulation and compared with test results to verify the validity of results. In this process, the vertical load and bending load are respectively calculated by the finite element simulation. Under the vertical load effect, the bucket foundation and the soil inside are regarded as a whole, and the corresponding buckling failure mode is obtained. The ultimate vertical bearing capacity is calculated using empirical and theoretical formulas; the theoretical formula is also revised by finite element results. Under bending load, the rotational center of the composite bucket foundation(in a region close to the bucket bottom) gradually moves from the left of the central axis(reverse to loading direction) to the nearby compartment boards along the loading direction. The H–M envelope line shows a linear relationship, and it is determined that the vertical and bending ultimate bearing capacities can be improved by an appropriate vertical load.

关键词： Wide-shallow composite bucket foundation Silty sand Off shore wind turbines

Condition Monitoring of turbines Using Nonlinear Mapping Method

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Wuhan University Journal of Natural Sciences 2004年第2期9卷 225-228页

作者： LiaoGuang-lan ShiTi-lin JiangNan SchoolofMechanicalScienceandEngineering HuazhongUniversityofScienceandTechnologyWuhan430074HubeiChina

Aiming at the non-linear nature of the signals generated from turbines, curvilinear component analysis (CCA), a novel nonlinear projection method that favors local topology conservation is presented for turbines conditions monitoring. This is accomplished in two steps. Time domain features are extracted from raw vibration signals, and then they are projected into a two-dimensional output space by using CCA method and form regions indicative of specific conditions, which helps classify and identify turbine states visually. Therefore, the variation of turbine conditions can be observed clearly with the trajectory of image points for the feature data in the two-dimensional space, and the occurrence and development of failures can be monitored in time. Key words condition monitoring - turbines - nonlinear mapping - curvilinear component analysis CLC number TP 17 - TH 17 Foundation item: Supported by the National Key Basic Research Special Found of China (2003CB716207) and the National Natural Science Foundation of China (50375047)Biography: Liao Guang-lan (1974-), male, Ph. D. candidate, research direction: fault diagnosis, pattern recognition and neural networks.

关键词： condition monitoring turbines nonlinear mapping curvilinear component analysis

Wide-range model predictive control for aero-engine transient state

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Chinese Journal of Aeronautics 2022年第7期35卷 246-260页

作者： Bing YU Zhouyang LI Hongwei KE Tianhong ZHANG Jiangsu Province Key Laboratory of Aerospace Power System Nanjing University of Aeronautics and AstronauticsNanjing 210016China Institute of Aeronautical Control System Wuxi 214063China

To perform transient state control of an aero-engine,a structure that combines linear controller and min–max selector is widely adopted,which is inherently conservative and therefore limits the fulfillment of the engine potential.Model predictive control is a new control method that has vast application prospects in the field of aero-engine control.Therefore,this paper proposes a wide-range model predictive controller that can control the engine over a wide range within the flight envelope.This paper first introduces the engine parameters and the model prediction algorithm used by the controller.Then a wide-range model prediction controller with a three-layer nested structure is presented.These three layers of the structure are univariate controller,nominal point controller,and wide-range controller from inside to outside.Finally,by analyzing and verifying the effectiveness of the univariate controller for small-range variations and the wide-range model predictive controller for large-range parameter variations,it is demonstrated that the controller can schedule the controller’s output based on inlet altitude,Mach number,and lowpressure shaft corrected speed,and ensure that the limits are not exceeded.It is concluded that the designed wide-range model predictive controller has good dynamic effect and safety.

关键词： Flight envelopes Model predictive control Predictive control systems Transients turbines

Impact of Reactive Power in Power Evacuation from Wind turbines

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Journal of Electromagnetic Analysis and Applications 2009年第1期1卷 15-23页

作者： Ashish Ranjan S. Prabhakar Karthikeyan Ankur Ahuja K. Palanisamy I. Jacob Raglend D. P. Kothari chool of Electrical Sciences Vellore Institute of Technology Vellore India Christian College of Engineering and Technology Ottanchatiram Dindugal District. India School of Electrical Sciences Vellore Institute of Technology Vellore India Vellore Institute of Technology University Vellore India

Application of Distributed Generation (DG) to supply the demands of a diverse customer base plays a vital role in the renewable energy environment. Various DG technologies are being integrated into power systems to provide alterna-tives to energy sources and to improve reliability of the system. Power Evacuation from these remotely located DG’s remains a major concern for the power utilities these days. The main cause of concern regarding evacuation is con-sumption of reactive power for excitation by Induction Generators (IG) used in wind power production which affects the power system in variety of ways. This paper deals with the issues related to reactive power consumption by Induc-tion generators during power evacuation. Induction generator based wind turbine model using MATLAB/SIMULINK is simulated and its impact on the grid is observed. The simulated results are analyzed and validated with the real time results for the system considered. A wind farm is also modeled and simulations are carried out to study the various im-pacts it has on the grid &nearby wind turbines during Islanding and system event especially on 3-Phase to ground fault.

关键词： Distributed Generation (DG) Grid Wind turbines Induction Generator Islanding Power Evacuation Point of Common Connection 3 Phase to Ground Fault

Use of Augmented Reality Methods to Support Legal Conflicts in the Planning Process for Wind turbines Using the Example of the Landscape Conservation Area “Eulenkopf and Surroundings”

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Energy and Power Engineering 2014年第11期6卷 349-361页

作者： Timo Wundsam Sascha M. Henninger Department of Physical Geography University of Kaiserslautern Kaiserslautern Germany

The world’s growing energy demand poses a serious problem. At the same time fossil fuels are finite, which we must work against. Therefore, the Federal Government of Germany has set itself the goal to push forward the use of renewable energy in order to completely do without the generation of nuclear energy by 2023. There are, however, no specific guidelines from the European Directive on the promotion of electricity from renewable energy sources for the internal electricity market regarding how high each share of the different production method should be and, above all, which specific aim should be achieved by the share of wind energy. Nevertheless, it presents a crucial step toward a nuclear phaseout and a concomitant change of course of the Federal Government of Germany in the spring of 2011 regarding the expansion of renewable energy, taking the nuclear catastrophe in Fukushima into account. Using new legal planning approaches, also including the area of Rhineland-Palatinate, opportunities should be provided to make previously protected land available for setting up facilities for the generation of renewable energy. However, it is important to examine the legal situation regarding the installation of these kinds of constructions more detailed, as no general statements can be made. This will be illustrated using the example of the landscape conservation area “Eulenkopf and surrounding area” in the district of Kaiserslautern. The stated goal of the Social Democrat/Green coalition of the federal state government of Rhineland-Palatinate is to considerably expand the generation of electricity from renewable energy sources so that by 2030 at least the entire electricity demand can be covered by those. Due to the enormous potential of wind power, it is therefore necessary to quintuple its share of electricity generation by 2020, compared to 2011 numbers. In order to achieve the desired political objectives, by 2030 the number of turbines has to be increased to around 2650, representing a capacity of 7500 MW. This in

关键词： Renewable Energy Wind Energy turbines Urban Planning Landscape Conservation Area Regulation Laws Augmented Reality Public Interest

Technical-economical optimization of horizontal axis wind turbines by means of the genetic algorithm

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Natural Science 2013年第12期5卷 1-8页

作者： Amir Jafary Moghaddam Abdollah Khalesi Doost Department of Mechanical Engineering Science and Research Branch Islamic Azad University Semnan Iran Mechanical Group Engineering Faculty Islamic Azad University Semnan Branch Semnan Iran

Wind turbine design is a trade-off between its potentially generated energy and manufacturing cost represented by the area of turbine surface in this research, and both factors are highly influenced by a number of design parameters. In this research, first, a weighted sum of these factors, with a negative weight for power, is assumed as the performance function to be minimized. Then, blade element modeling was performed for class NACA turbines to estimate the generated power based on the effective wind velocity in the area. As a novelty, a new algorithm based on fuzzy logic was proposed to determine the effective wind velocity by using the history of wind velocity in the area. The wind velocity, therefore, the generated power by a wind turbine, is largely dependent on its operation area. In the end, the genetic algorithm with decimal numeric genes was employed to determine the optimal design parameters of the turbine based on the recorded data. This study resulted in a computer program which integrated calculations of fluid dynamics into the genetic algorithm to optimally determine an appropriate turbine (its geometric parameters). The implementation of the proposed method on two different regions ended up with the design of the blade NACA5413 for Manjil and the blade NACA4314 for Semnan, both in Iran.

关键词： Horizontal Wind turbines Genetic Algorithm Element Modeling of the Blade Fuzzy Sets Optimization Iran

Cardiovascular System Response to Chronic Exposure to Emissions from Gas turbines Power Plants

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World Journal of Cardiovascular Diseases 2020年第4期10卷 208-224页

作者： C. D. Ekpruke V. I. Iyawe Department of Physiology School of Basic Medical Sciences University of Benin Benin-City Edo State Nigeria

Objectives: Heart Rate and Blood Pressure have been reported to be susceptible to the effects of air pollution. Effect of emissions from gas turbine power station among workers is relatively unexplored. Therefore, this study aimed at assessing the effect of emissions from gas turbines on cardiovascular functions and C-reactive protein level in workers of power generating stations. Methodology: 440 individuals made up of 228 workers of gas-fired power plant stations and 212 non-power generating station workers volunteered for this study. A detailed questionnaire was carefully filled by volunteers and anthropometric data measured and recorded. Blood pressure, heart rate and C-reactive protein level (CRP) were measured using standard laboratory techniques in all subjects. Results were presented as Mean ± Standard Error of Mean (SEM) and appropriate analysis was done using Independent student’s t-test and Analysis of Variance (ANOVA). P-value Results: Result showed increased systolic blood pressure (SBP), 142.45 ± 8.87 mmHg of test subjects compared to that of the control (P 0.05) which was 121.32 ± 2.25 mmHg. However, there was no statistically significant difference in the Diastolic Blood Pressure (DBP) of the test and control groups. The Pulse Rate (PR) increased significantly in the test group (89.00 ± 0.02 bpm) when compared to that of the control group (74.34 ± 1.23 bpm). There was also an elevated plasma level of CRP, 6.69 ± 0.03 mg/L in the test group compared to the control (P Conclusion: Exposure to gas emission from natural gas-fired power plants on workers of power generating stations increased SBP, PR and C-reactive Protein level.

关键词： Emissions Heart Rate Systolic Blood Pressure Diastolic Blood Pressure Gas turbines

Vibration Signals and Condition Monitoring for Wind turbines

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Engineering（科研） 2013年第12期5卷 948-955页

作者： Dimitrios Koulocheris Georgios Gyparakis Andonios Stathis Theodore Costopoulos School of Mechanical Engineering National Technical University of Athens Athens Greece

Rolling element bearings are critical parts of modern wind turbines as they carry the loads of the turning structure and the wind force. The stochastic nature of the wind loads makes it difficult to estimate the useful operational life of the bearings. Condition monitoring of these bearings in a real time environment could be very helpful in estimating their performance and in scheduling maintenance actions when a condition-based maintenance strategy is followed. This procedure can be successfully implemented by using vibration analysis in the time domain or in the frequency domain, giving useful results about the current condition of bearings and the location of potential faults. Permanently located transducers on proper positions on the bearings’ housings can be used in order to collect, process and evaluate real time measurements and provide information about the bearing’s performance. In this work, a test rig is utilized in order to evaluate the performance of rolling bearings. The results of the experimentation are satisfactory and the progress of fatigue failures can be predicted through vibration analysis techniques showing that implementation in real scale may be useful.

关键词： Wind turbines Bearings Basic Rating Life Maintenance Condition Monitoring Vibration Signals