bluuebunny/crossref_metadata_2025 huggingface dataset:
Temperature Measurement System within the High-Voltage Switchgear Based on Wireless Networking Technology
Authors: Feng Kai , Ying Zhan Feng , Wu Jun Ji , Chen Yun Yun
Published: June 2012

Based on the study of equipment condition monitoring problem in smart grid. Make an improvement to traditional wireless temperature measurement system within high voltage switchgear, according to electromagnetic shielding problem within switchgear and energy wastage problem of AD sampling method, proposes a new type of wireless network communication mode group and RC circuit temperature measurement method. Testing results in laboratory shows a promotion in terms of data accuracy and communication reliability, and a significantly energy-saving effect relative to traditional methods.
The Influence of Insulation Bushing on Insulation Performance of Vacuum Insulated Tubing Coupling
Authors: Zhao Hai Qian , Wang Zhong Hua , Liu Xiao Yan
Published: June 2012

In the injecting steam wellbore, insulated tubings are connected with couplings. The coupling is short, but its insulation performance is poor. There are two different coupling types: couplings with insulation bushing and couplings without insulation bushing. By combining on-site experiments and fluent simulation, thermal insulation performance of coupling with insulation bushing and without insulation bushing were discussed. The results showed that the apparent heat conductivity of the coupling with insulation bushing is about 0.4W/(m•K), the apparent heat conductivity of the coupling without insulation bushing is about 3.6 W/(m•K). Insulation bushings promote insulation performance of vacuum insulated tubing coupling significantly.
Induction Drive Motor's Fault Diagnosis Research with Application
Authors: Yuan Xiao Hua , Dai Xian Bin
Published: June 2012

A number of induction machine is widely used in people's daily life and agriculture manufacture, and the chance to meet all kinds of breakdown is large. Electrical machine's breakdown not only damage electrical machine itself ，but also make electrical machine suddenly break down and product line breakdown, result in great economy's loss and fatal result. So, research on electrical machine's fault diagnosis' technology, Possess significant theory's meaning and society economic benefit. Texts according to induction drive motor's common breakdown's feature, Directing to the past research settle electrical machine's breakdown's means's fault , Bring up base on improve the smallest two ride stand by vector machine (LS- SVM) de induction drive motor's fault diagnosis' means. Adopt muddleheaded optimization algorithm, Seek come out possess compare strong popularize ability de parameter. Combine induction machine's structural parameter with performance export model de build mold example, with cross validation techniques to compare confirm research means be used for motor fault diagnosis de validity.
AC Motor Speed Control Double Close Loop Cascade Fuzzy PI Controller Design
Authors: Li Shuang Shuang , Liu Yong Xin
Published: June 2012

Cascade Speed Regulation System has the nonlinear characteristics and whose structure parameters are variable easily. Fuzzy control theory which based on conventional Cascade Speed Regulation System is introduced into such system. An asynchronous motor model is built, and a fuzzy parameter self-tuning controller is designed in this paper, the controller is simulated in Matlab, The simulation result shows the difference between the conventional PI controller and the fuzzy parameter self-tuning PI controller. From these simulation results, all performance indexes of the fuzzy PI controller with parameters self-tuning are vastly superior to those of the conventional PI controller.
Control System Study of the Heavy Handling Robot Based on S3C44B0X
Authors: Sun Xiang Guo , Yang Da Zhi , Liao Ying Hua
Published: June 2012

Heavy handling robot can transport goods automatically from the origin to the destination along the guide wire. During the operating process, light sensors are firstly employed to detect the robot’s relative position of guide wire, the test data can be brought in microprocessor S3C44B0X to be saved, analyzed, and processed, and then, according to the results of the information processing and the pre-set control algorithm, the system gives off the corresponding instruction and guides the robot along a pre-drawn line running smoothly to achieve the purpose of carrying the goods automatically. Heavy handling robot can be widely applied as an intelligent vehicle to workshop, factory, dock and other places.
Design of Dual-Frequency Microstrip Patch Antenna
Authors: Yang Jun Xiu , Li Lin , Zhao Wen Lai
Published: June 2012

A dual-frequency microstrip patch antenna is proposed based on rectangular microstrip patch, with appropriating feed location selection of 50Ω coaxial line, two frequency are respectively applied to 0.8GHz and 0.9GHz. Size of antenna is designed based on the simulation software of HFSS from ANSOFT company, reducing antenna return loss by adjusting size and completing matching between patch and coaxial line, results are analyzed. Simulation results show the design and implementation of microstrip patch antenna have certain reference value with small return loss on 0.8GHz and 0.9GHz.
Design of the Calibration PC Software for Motorcycle Electronically Controlled Engine System Based on LabVIEW
Authors: Yang Tie Zao , Qian Chang Jun , Wang Chang Sheng , Chen Xian Chang , Yuan Lei
Published: June 2012

This article developped a Calibration PC software for Motorcycle Electronically Controlled Engine System based on LabVIEW ,This software can accurately control the calibration parameters of engine working process,including injection pulse width and ignition timing.It is flexible, intuitive and convenient to motorcycle electronic control system’s calibration processing with the software of host computer monitoring by using LabVIEW.
Investigation of Output Power and Efficiency of Wound-Rotor Brushless Doubly-Fed Machine
Authors: Zhang Jun , Wang Xue Fan
Published: June 2012

Brushless Doubly-fed Machine (BDFM) is a new type of the induction machine, which has wide application in the fields of variable-speed generator and drive systems. The key factor affecting its performance is the rotor structure. In this paper, taking wound-rotor BDFM for instance, firstly, according to the relationship between the equivalent circuit parameters of the BDFM, the core equivalent circuit model of the BDFM has been derived. Secondly, based on the core equivalent circuit model and the constraints of electromagnetic load, the power distribution between the power and control windings and the constraint condition of maximum output of active power has been obtained. Thirdly, according to the simplified model of the equivalent circuit, the copper loss and the relationship between the output power and efficiency of the machine have been investigated. Finally, the anlysis results are verified by the experimental data.
Research on Cogging Torque for Low-Speed and Direct-Drive PMSM
Authors: Zhang Bing Yi , Wang Sen , Feng Gui Hong
Published: June 2012

The paper attempts to present some effective methods to reduce cogging torque for low-speed and direct-drive(LSDD) permanent magnet motor.
Research on the Feasibility of a New Cooling System of Stator Collecting Ring in Hydro-Generator
Authors: Dong Hai Hong , Ruan Lin
Published: June 2012

As a new generator cooling technology, the evaporative cooling technology has the advantages of high-security, energy-saving and high efficiency. To solve the more serious problem of the large quantity of heat generated by stator collecting ring in huge hydro-generator, a new cooling system, the self-circulation inner evaporative cooling system of stator collecting ring, was proposed in this paper. To analyze and discuss the feasibility and operation characteristics of this new cooling system, an experiment platform of self-circulation evaporative cooling system of stator collecting ring was established with extremely asymmetric parallel flow branches. The experimental results show that under different heat loss work conditions, the experimental cooling system can operate normally. Under the rated work condition, the system can meet the cooling demands of actual generator and the wall temperature distribution of stator collecting rings is comparatively even. The feasibility of this new cooling system is confirmed. The conclusions in this paper provide the basis for the further research of this new cooling system.
Research on the Temperature Distribution of Stator Collector Ring in Evaporative Cooling Hydro-Generator
Authors: Dong Hai Hong , Ruan Lin
Published: June 2012

The self-circulation inner evaporative cooling system of stator collector ring is a new cooling system for stator collector ring in hydro-generator, with the advantages of high-security, energy-saving and high efficiency. In this paper, the temperature distribution of stator collector rings in the new cooling system under different work conditions, were analyzed theoretically by simulating. The chosen correlations of flow resistance and heat transfer were introduced. Comparing with the experimental data, the simulation results show that the prediction precision of the temperature distribution of stator collector ring is satisfying with maximum relative error less than 9.13%. The simulation method in this paper is reliable and can be utilized in the applied engineering field.
Research on Vector Control and PWM Technique of Six-Phase PMSM
Authors: Su Jian Yong , Yang Jin Bo , Yang Gui Jie
Published: June 2012

The mathematic model that based on decoupling vector space for six-phase permanent magnet synchronous motor (PMSM) is established. The six-phase PMSM is designed with two sets of Y-connected windings phase shifted by 30 electrical degrees. In the model, the variables of the motor are mapped to the α-β subspace associated with the electromechanical energy conversion and z1-z2 o1-o2 subspace that has nothing to do with the energy conversion subspace in the model. The model implies that different current harmonics have different effects on electromechanical energy conversion. The vector control scheme for six-phase PMSM is presented, in which the currents in the subspace α-β and z1-z2 are controlled in closed loop. A space vector pulse width modulation (SVPWM) algorithm of six-phase voltage-source inverter based on adjacent four largest voltage vectors is discussed. The voltage in α-β and z1-z2 can be modulated simultaneously. Through the simulation and experiment analysis, the vector control method and PWM technique for six-phase PMSM are proved to be feasible and effective.
Simulation of a Rotor Flux Oriented Induction Motor Drive
Authors: Chen Xiao Jie
Published: June 2012

The synchronously rotating vector components of the stator current isq and isd are controlled independently to control the torque and the rotor flux, respectively. It can be shown that rotor flux orientation in contrast to stator flux orientation tends to give true decoupling control. Within the synchronous current, the respective counter EMF (Electro Motive Force) signals can be added (or subtracted) to enhance the current loop response. The unit vector signal thetas that transforms the synchronously rotating stator voltage into stationary frame signals has been generated from the speed signal and slip signal which is a function of isq.
Studies of Large-Range Dynamic and Static Motor Torque Tester
Authors: Ding Chang Hong , Li Hong Zuo , Cheng Ji Hang , Xu Shuang
Published: June 2012

This paper discusses the composition, structural features, working principle, and technical performance of a kind of motor torque measurement system. This system adopts two kinds of torque measurement methods, dynamic torque measurement method and static torque measurement method, uses microprocessor to collect data including rotational speed of load motor and torque signals of to-be-tested motor, figures out the rotational speed and torque through software algorithm, as well as displays and output them. This system also makes actual measurement of a type of motor. The measurement period is short; the measurement precision is high; and the performance is stable.
Experimental Investigation on Compound Combustion of Partial Premixed Charge Compression Ignition – Direct Injection Engine Fueled with Dimethyl Ether
Authors: Li Wei , Wang Wen , Wu Wei Peng
Published: June 2012

In order to enlarge the operating range at HCCI mode and explore the scientific methods to realize the ultra-low emission with DME as alternative fuel. Experimental investigation on the realization of PCCI-DI combustion is carried out on a single cylinder and naturally aspirated direct injection diesel engine. The method to achieve the PCCI-DI mode is that feeding part of DME into intake pipe to produce Pre-mixed homogeneous mixture and injecting the other part of the DME fuel into the combustion chamber by the original fuel injection device in the late stage of compression stroke. Results indicate that the engine can be operated at a wider range of speeds and loads at PCCI-DI mode. The brake thermal efficiency increases and NOx emission reduces. However, HC and CO emission increase. It is also indicated from experiments that NOx, HC and CO emission increase with an increase of DME premixed quantity. Furthermore, the optimum fuel supply advance angle for PCCI-DI mode could be delayed 6~8 °CA on the base of DME DI mode.
Adaptive Control Research and Design Based on STC Single-Chip Microcomputer
Authors: Xu Qiang , Zhang Qian , Ren Kai Chun , Zhang Xing Qi , Li Shi Gang
Published: June 2012

This paper analyses the characteristics and the glowing use value of LED lights, using STC series microcontroller design a system of LED which can automatically adjust the light according to the environment changes. The control system consists by the data acquisition module and control module and circuit driver module. This paper gives the control circuit hardware and software design. This system has many advantages such as energy conservation and environmental protection and longevity when compared with the conventional lighting system.
Cubic-Like Nickel Oxide Nanostructures as Large Specific Capacitance and Long-Life Supercapacitors
Authors: Deng Jia Wei , Pang Huan , Wang Shao Mei , Zhang Jiang Shan
Published: June 2012

Monodispersed anamorphic cubic NiO materials have been synthesized by a simple method. SEM, TEM and XRD have been employed for the morphology and structure characterization. The calcination conditions have been carefully studied about their effects on supercapacitor properties. Electrochemical data prove that the monodispersed nano anamorphic cubic NiO materials contain a good specific capacitance and excellent specific capacitance retention after 2000 continuous charge-discharge cycles. These results suggest that both the morphology and structure have important effects on the high performance supercapacitors.
Local Radial Point Interpolation Method and Finite Volume Method for the Fully Developed Magnetohydrodynamic Flow and Heat Transfer
Authors: Cai Xing Hui , Xu Peng , Zhu Man Lin , Gao Yun Liang , Ji Guo Xun
Published: June 2012

In this paper, a local radial point interpolation method is given to obtain the numerical solutions of the coupled equations in velocity and magnetic field for the fully developed magnetohydrodynamic flow through a straight duct of rectangular section with arbitrary wall conductivity. Computations have been carried out for different Hartmann numbers and different wall conductivity. Since the energy equation is uncoupled with velocity and magnetic field for the fully developed magnetohydrodynamic flow, the finite volume method, which is effective on heat transfer problems, is applied to solve the energy equation with the obtained velocity fields.
Analysis of Air Gap Harmonic Magnetic Field and Electromagnetic Vibration of a Permanent Magnet Motor
Authors: Li Yan , Zhang Zeng Jie , Xia Jia Kuan , Feng Gui Hong
Published: June 2012

Electromagnetic vibration is produced by radical exciting force waves acting on iron cores of permanent magnet motors. In order to reduce radial electromagnetic force, a surface mounted permanent magnet synchronous motor was analyzed. According to the electromagnetic force wave of analytical formula in the case of no-load, the main force wave order and force wave frequency were analyzed. Properly selecting the pole arc coefficient could reduce the amplitude of electromagnetic force. By finite element analysis, the results show that reduce the sinusoidal distortion rate of the flux density, electromagnetic vibration of the motor can be reduced to some extent, but not the best choice.
Arc-Shaping of Magnets for Reduction of Cogging Torque in Permanent-Magnet Synchronous Generators
Authors: Cheng Chao Yuan , Hsiao Chun Yu , Chung Shu Wei , Chiang Chun Pin , Chin Zai Wei
Published: June 2012

Wind power is an important source of green power. The equipment, generators, and power systems are all determining factors of equipment efficiency. High efficiency generators of medium and small size are widely used in daily life. Cogging torque is a major issue affecting generator efficiency. This paper proposes an optimized design for permanent-magnet synchronous generators using arc-shaped magnets to reduce cogging torque. The proposed approach improves performance significantly.
Case Study of Surge Protective Devices (SPDs) in Low-Voltage System
Authors: Lin Ching Lung , Jeng Yoau Chau , Tsai Mei Fen , Weng Lin Song
Published: June 2012

Because the electric system of Tai-power is increased day by day, no matter generating set, transmission line, and transformer in substation, have especially already set up and increased aircrew's model parameter newly to use the number value that the producer offers in the part of the generating set, also there are no materials that a producer offered in the old aircrew, can only use typical value to substitute. Because the model parameter surveying value of system analysis, the accuracy of analysing the result of incomes remains to be discussed, so carry on the fixed quantity on the spot and examine the parameter of models to the systematic generating set, apply it to system analysis as the very urgent important affair. The purpose of this research is to set up the.
Design of Triggering Device for VFTO Measurement System
Authors: Yue Gong Chang , Jia Yu Rong , He Jia Xi , Liu Wei Dong
Published: June 2012

Very fast transient overvoltage (VFTO) can be generated during the operation of disconnect switch (DS). Especially in ultra high voltage (UHV) gas insulated substation (GIS), VFTO is a threat to the safety of the power system equipment. It is very important to measure VFTO waveforms accurately. VFTO waveforms are comprised of high frequency voltage superimposed on the power frequency voltage in source side of DS and high frequency voltage superimposed on step-wise voltage in load side. How to trigger oscilloscope to acquire data is a big problem in measuring process. According to the features of VFTO waveforms, new triggering device consisting of a high pass filter is designed. The output of measurement sensor is used as the input of the high pass filter, and the output of the high pass filter is used to trigger oscilloscope. When the DS is not operated, there are no signals output from the high pass filter and the oscilloscope is waiting for trigger. After the operation of DS, the high frequency signals will pass the filter to trigger oscilloscope to acquire data. The device can guarantee the oscilloscope to complete a data acquisition properly.
Field Analysis and Control of Angle of a Magnetic Levitation Micromotion Stage
Authors: Lei Yong , Gao Er Jin , Chen Jian Guo , Chen Ben Yong
Published: June 2012

This paper analysis the characteristic why Halbach array field is an one side field and give the formulation from current to drive force. Modeling dynamic and designing the control system for the control of angle movement of magnetic levitation stage. Control the movement of angle with PID controller precise. Simulation result and precision analysis indicate this magnetic levitation micromotion stage has good dynamic characteristic of angle movement controlled and it can realize microscale resolution.
Grounding Grids Fault Diagnosis Based on PCA-BP Neural Network
Authors: Liu Xian Feng , Peng Min Fang
Published: June 2012

In order to solve the problem of needing to build accurate mathematical model in grounding grids fault diagnosis ,a new method for applying to the study of grounding grids fault diagnosis,which was based on BP neural network and improved by PCA theory，was introduced.The PCA(Principal component analysis)method was incorporated into the network,which not only solved the linear correlation of the input, but also simplified the network structure and reduced the parameters of neural net input. It realized optimum compression of fault sample data and enhanced classification speed and precision. The experimental results demonstrated that the method could decrease the number of the network input nerve cells effectively, and enhanced study efficiency and diagnosis accuracy. The way had very good fault distinguishing ability and vast prospect.
Research of Cold Test in 170t/h Tangentially Fired Boiler
Authors: Xiang Yu Hua , Zhang Jia Yuan , Zhang Xiao Hui
Published: June 2012

The characteristics of the WGZ170/9.8-3 pulverized coal boiler were obtained based on cold test，Including the air velocity distribution in tangential firing boiler and the relation between air distribution with opening of each secondary air dampe，The test results had determined that the baffle of blower at around 40% and two parallel draft fan about 45% were relatively appropriate. and the air distribution and opening of each secondary air dampe and balancing the distribution of primary air and second air along the width direction of the boiler hearth were confirmed through test，and the aerodynamic field inside the boiler was investigated based on the tie-floating test．and good aerodynamic field can be obtained after distributing the primary air and second air reasonably，which guarantee the ignition and stable operation of the boiler．
The Localization Method of Active Olfaction Robot and Experimental Study
Authors: He Ning , Yang Jian Hua
Published: June 2012

An active olfaction implementation scheme based on zigzag search algorithm using a wheeled mobile robot and the experimental verification are put forward. Firstly, the hardware structure of the active olfaction robot is setup. Secondly, the Zigzag-based robot active olfaction dynamic system implementation procedure in the simulated environment is presented, including plume finding, plume tracking and odor source declaration, and simulation results validate the proposed search scheme. The entire system was used under steady wind condition to locate the ethanol odor source. Choice 15m as the start distance, and after 10 times locating, the error is less than 5% and the experimental results prove that the system recognition is accuracy.
The Research of Digital Learning Applying to Industrial Wiring Course Excerpt
Authors: Wang Chih Chung , Chen Tsair Rong , Wei Jong Bi
Published: June 2012

“Industrial Wiring” Generally Use in Industrial Circle for High Pressure Switchboard, Low Pressure Switchboard, Motor Starters and Control Panel Etc. Assembly, and Is One of the Main Events of Vocational Training. in Traditional Learning, Teachers Will Explain the Circuit and Do the Demonstration, and then Students Will Proceed Self Study or Practice Etc Training Method. in this Kind of Method, Students Mostly Can Not Prove Immediately and Cause Inaccuracy with Wiring Concept. in View of Digital Teaching Material Is Producing and Developing Maturely, and it Has Been Promoted Generally as a Popular Way for Teaching. Digital Learning’s Advantages Include No Time Limit or Space Limit, Saving the Human Recourse and Consumables Cost, and Lively and Abundant in Teaching Material. as a Result, this Research Would Put Digital Learning into Industrial Wiring Course, to Create Digital Teaching Material to Build up Learning Benefit Result and to Spirit up Learning Interest. this Research Takes 70 Electric Machinery and Electron Students from Vocational High School and the Experiment Makes Two People as a Group to Proceed Academic and Technical Learning. during the Experiment, 36 Students Will Use Computer Simulated Mode as Digital Learning, and the other 34 Students Learn by Dictated Demonstration in Traditional Learning Way. after the Class, the Two Groups of Class Take a Quiz Separately, Including Electrical Science Basic Ability Test, Industrial Wiring Achievement Test, Cognition Load Chart and Space Ability Test to Comprehend the Benefit Result of Applying Digital Learning. Students’ Composite Grade Indicates that Digital Learning (M=24.87) Overmatch the Traditional Learning (M=19.63). Therefore Could Make Four Conclusions. First, Digital Learning Benefit Is Better than Traditional Learning. Second, Digital Learning Create a Higher Cognition Load than Traditional Learning Does. Third, Digital Learning’s Learning Result Does Not Have any Difference for Different Space Ability Learner. Fourth, Computer Is a Useful Communication Tool in Digital Learning and it Helps to Group Interaction.
Dynamic Analysis of the Nonel Rotary Piezoelectric Generator
Authors: Han Bing Feng , Chu Jin Kui , Yao Fei , Xiong Ye Sheng , Huo Xin Xin
Published: June 2012

The method to transfer energy by less-contact magnetic force can decrease mechanical energy loss comparing with that by mechanical contact. In this paper, a novel piezoelectric rotary generator was designed based on the theory of the transition from less-contact magnetic force to the mechanical energy. ANSYS software was used to calculate the driving forces for the piezoelectric cantilever beam from the rotary wheel rotate in the different positions. The periodic driving force for the piezoelectric cantilever beam was obtained by the methods of fitting and Fourier transform. Laws of dynamic performance for piezoelectric cantilever beam were obtained by dynamic analysis. The results show that the low-frequency and variable rotational mechanical energy in the natural environment can be harvested by this novel rotary piezoelectric generator.
Modeling and Analysis of the Thermal State of Power Connector with the Safe Membrane
Authors: Xi Jian Jun , Zhao Jun
Published: June 2012

The connector overheating is the cause of an accident of power system. It is a common way to apply conductive paste on the connector to avoid corrosion and overheat. This paper analyses the thermal state of the power connector with safe membrane by electric-thermal coupling model. It is concluded that the membrane is affected by permittivity itself.
A Study on the Stability of Marine Gas Turbine Generation Module Power System
Authors: Wang Zhi Tao , Li Shu Ying , Huang Xiao Xia , Li Tie Lei
Published: June 2012

Based on modular modeling idea, the modular model of marine generation system was set by the technology of systematic simulation. One set of simulation models of marine gas turbine generation system was generated. Results show that flywheel energy storage device can enhance the stability of power grid and play a better role in making marine gas turbine generation system stable under heavy load fluctuations.
Highly Efficient White Polymer Light-Emitting Diodes with a Conjugated Polyelectrolyte as Host Polymer
Authors: Niu Qiaol , Zhao Ling Zhi , Zhang Yong , Li Xin , Wang Yong Li
Published: June 2012

In this presentation, efficient white polymer-light-emitting diodes have been fabricated with high work-function cathode. The device structure consists of ITO/poly(ehtlenedioxythiophene) : poly(styrene sulfonic acid) (PEDOT : PSS) / poly(N-vinylcarbazole) (PVK) / poly[(9,9-bis(30-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt- 2,7-(9,9-dioctylfluorene)] (PFN): bis(2-(4,6-difluorophenyl)-pyridinato-N,C2') picolinate (FIrpic): poly[2,7-(9,9-dioc-tylfluorene)-co-(4,7-dithien-2-yl)-2,1,3-benzothiadiazole] (PFODBT15)/Al. By tuning the weight ratio of FIrpic to PFO-DBT15 in PFN, white light was obtained. The 1931 CIE coordinates of the white lights obtained were (0.37, 0.41) and (0.36, 0.42). The maximum luminous efficiency was 3 cd/A.
Study of the Repetition Pulses Based on Hydrogen Thyratron
Authors: Yu Cheng Da , Deng Qi Bin , Li Zhi Qiang , Wang Yong Feng
Published: June 2012

Repetition pulses with sub-microsecond arising time, high voltage and large current, have been widely utilized in the field of production and scientific research, in which the gas spark switch is usually selected because of the large state current and the high operating voltage. However, due to the recovery property of gas ionization, it is hard to get the repeated switch-on and switch-off at a high rate towards the conventional gas spark switch. Owing to the reliably triggering and faster arising time, the hydrogen thyratron is found to be more suitable for the switch to generate the repetition pulses at a high rate. In this paper we proposed a novel design of repetition pulses, in which it gets a several times high voltage output based on the inductive-adder, by using the hydrogen thyratron switch with a low operating voltage, and then we analyze the magnetic field distribution under the structure of the coaxial cable and describe the design of high voltage repetition pulses in details
Study on the Intervascular Two-Phase Flow Characters of Horizontal-Tube Falling Film Evaporator
Authors: Fei Ji You , Guo Qi Chao , Li Hua , Deng Ran
Published: June 2012

In this paper, the mathematical model of a horizontal-tube falling film evaporator that used in air condition and refrigeration system was founded. The evaporative tubes of the evaporator were cold and staggered arrangement. The numerical simulation of the intervascular flow of the oil-bearing refrigerant R134a was carried out, under the conditions of varies flow mode and varies structures of distributed equipment. Under the standard condition of air conditioning, the study of the intervascular two-phase flow characters of the horizontal-tube falling film evaporator were analyzed in the last. The research achievements can provide theoretical laws for relief the effects of the intervascular vapor shear stress on the quality of the liquid film formed outside the evaporative tubes. And the conclusions have practical and guide means for the horizontal-tube falling film evaporator design and evaporative tubes arrangement optimization.
A New Method of Improving Steam Injection Profile Distribution Used in Thermal Horizontal Well and Experimental Study
Authors: Zhu Xiu Xing , Xue Shi Feng , Tong Xing Hua
Published: June 2012

During the production of thermal horizontal well, recovery ratio will be reduced by the deficiency of traditional steam injection methods, which include finite effective heating range, poor level of producing reserves etc. In order to improve efficiency of steam and well yield，a new method—multipoint steam injection technology is presented in this paper, which can improve steam injection profile distribution in thermal horizontal wells. Several factors including multiphase flow, pressure drop, variable mass flow and reservoir heterogeneity, are taken into consideration in this method. By the new technology, Steam injection string used in horizontal wells is divided into several independent units through applying matching equipments. Based on the optimization of steam absorption capacity of every unit, steam injection profile distribution is improved. The validation of multipoint steam injection technology and matching equipments are verified through ground simulation tests in this paper. Moreover, the influence of steam injection parameters is also analyzed.
Analysis of Air Source Heat-Pump System Assisted by Solar Energy
Authors: Su Shun Yu , Huang Qin , Chen Jian
Published: June 2012

The steady state distributed parameter model of heat exchangers in a heat-pump system was established in this paper. The calculating results of refrigerant quantities in the heat-exchangers show that refrigerant charge quantity in heating operating condition is less than that in refrigeration operating condition. Based on the differences of refrigerant mass flux between refrigeration and heating conditions, the exhaust bypass method to improve the operation efficiency of the heat-pump system was presented. And in order to prevent frosting on the surface of outdoor heat exchanger of the air source heat-pump, the solar energy assisted strategy was also applied in the heat-pump system.
Discuss of Important Issues in Numerical Simulation for Natural Draft Counter Flow Cooling Tower
Authors: Song Li , Tian Rui , Li Song , Wang Ya Hui
Published: June 2012

natural draft counter flow cooling tower heat and mass transfer numerical simulation has been widely used to optimize the cooling tower design and to improve the thermal efficiency, but in published papers, a few important problems is not attracted attention, such as how does impact grid density to the calculation results; how does impact change of atmospheric density to the calculation results; drop diameter is an important parameter in numerical simulation, but it is not a exact experimental data, it is important to discuss how does impact drop size to the calculation results. This paper will explore and analyze these issues in the numerical simulation.
Entropy Analysis and Optimization of Phase Transition Heat Exchangers
Authors: Wang Jian , Chen Hu , Huang Hong Biao , Tao Han Zhong
Published: June 2012

Entropy analysis method was adopted to analyze and optimize a jacketed pipes-type heat pipe steam generator. In the entropy analysis process, the entropy production resulted from the total temperature difference across the heat exchanger, the entropy production from main heat transfer element – heat pipes and the entropy production caused by the pressure drop due to working media flow on cold and hot sides were taken into consideration. In the calculation, the entropy production in all parts of the heat exchanger was analyzed row by row in a discrete pattern, except for the entropy production due to pressure drop on flue gas side. Analysis results show that for the heat exchanger in this case, the proportions of entropy production in the above-mentioned three parts are respectively 74.79%, 21.75% and 3.46%. On this basis, the article also made optimizing analysis with the cold and hot source temperature, heat pipe length and No. of heat pipe rows as parameters, to provide theoretical basis for further improving the energy efficiency of heat exchangers.
Air Side Heat Transfer Characteristics of Wavy-Finned-Tube in a Forced Draft Direct Air-Cooled Steam Condenser
Authors: Zhang Zhao Ying , Yang Jian Guo , Zhang Hai Zhen
Published: June 2012

An experimental study was performed on wavy-finned-tube used in forced draft direct air-cooled steam condenser (DACSC) under actual working conditions of the power generating unit. Tests were carried out to study the air side heat transfer characteristics of wavy-finned-tube in actual operating conditions of DACSC, such as: air temperature, air face velocity, environmental temperature, exhaust pressure of steam turbine and temperature of exhaust steam. The air-side heat transfer characteristics of wavy-finned-tube heat exchangers were tested and analyzed by varying air face velocity .One empirical correlations for predicting the h-factor was developed.
Integral Analysis of Heat Transfer on Falling Laminar Liquid Film with Constant Heat Flux
Authors: Peng You Shun , Yang Li , Du Yong Cheng
Published: June 2012

Integral analysis of heat transfer of a laminar falling liquid film along a vertical heated plate with specified heat flux boundary condition was investigated. The temperature distribution of liquid film was obtained by utilizing an integral analysis method, which was compared with numerical solution and other researcher’s results. In this analysis a new concept of thermal changing point was put forward. It’s found that the Nusselt number has a characteristic relationship with thermal changing point, which is obtained by calculation. When the film flow distance is less than thermal changing point, the Nusselt number decreases rapidly. When the film flow distance is greater than or equal to thermal changing point, the Nusselt number reaches to a fixed value. A larger Peclet number or lower initial temperature generally leads to a larger Nusselt number in entrance region, whereas the wall heat flux is found to have no influence on the Nusselt number.
Heat Transfer Performance Analysis of Horizontal Ground Heat Exchanger under the Artificial Lake
Authors: Yu Zhong Yi , Chen Yan Hua , Tang Xiao Liang , Lei Jian Ping
Published: June 2012

According to the application conditions of horizontal ground heat exchanger(HGHE) under artificial lake, this paper uses numerical simulation method to do dynamic simulation research of the heat transfer performance of HGHE, analyzes the effect of connection mode and pipe flow velocity on heat transfer performance of HGHE in detail，puts forward efficient HGHE loop formation mode，and will provide effective technical support for ground-source heat pump system design with HGHE.
Integration Design of High-Effective Stove-Cooking Utensil Based on the Research of Enhanced Heat Transfer
Authors: Peng Xiao Hui , Xu Shun Sheng , Zhong Yong Wen , Tian Li Jun , Zhang Zhi Jie , Deng Wen Chuan
Published: June 2012

The level of domestic gas utensils energy utilization efficiency decides the energy saving efficiency and economical efficiency of the gas utensils. In this paper, considering the stove-cooking utensil as the object of study, on the basis of deep research of stove-cooking utensil system’s high-effective heat transfer, high-effective heat preservation technology, combing the technology of high-effective burning, high-effective heat transfer, high-effective heat preservation, a stove-cooking utensil system that is of high-effective heat transfer, high-effective heat preservation, low cost, low exit flue gas temperature is designed and the stove-cooking utensil system’s energy efficiency is improved significantly by comprehensive designing and researching of the insulation lid, the bottom of pot, and the radiant panel on the condition of keeping high-effective burning.
Kinetic Simulation of the Promoted Effect of Methanol on the NOxOUT Process
Authors: Guo Lu Yang , Wei Feng Nian , Liu Zhi Chao , Zhang Shu Wei , Niu Sheng Li
Published: June 2012

Subscript textThe kinetic model for simulating the mechanism of the promoted effect of methanol on the NOxOUT process has been established and it mainly includes the optimal sub-mechanisms respectively for the NOxOUT process and the chemical reaction of methanol. The oxygen concentration does not obviously influence the maximum NO reduction efficiency in the range of 1-6 %, but the temperature window is overall shifted to lower temperature zone with oxygen concentration increased. Meanwhile, the mole ratio of urea to nitric oxide by a factor of 2 should be maintained between 1.5 and 2 from both the efficiency and running cost view. Also, ample residence time of 300/T-400/T s must be guaranteed for the reduction occurring thoroughly. Methanol does not compromise the maximum NO reduction efficiency and broadens the temperature window towards low temperature zone. The promoted mechanism of methanol on the NOxOUT process is the abundant OH formation through the methanol regenerative reaction of CH2OH/CH3O+H2O=CH3OH+OH and methanol should be maintained at 50-100 ppm for an obvious promoted effect. During the co-injection of methanol and urea, the “ammonia slip” is depressed, especially at 1173 K where the promoted effect on NO reduction is obvious, but emission of nitrous oxide is also markedly increased at this temperature.
Physical Rules Based Adaptive Neuro-Fuzzy Inferential Sensor Model Design and Analysis in Predicting the Indoor Temperature in Heating System
Authors: Huang Liang , Liao Zai Yi , Ge Hua , Zhao Lian
Published: June 2012

The previous research on adaptive neuro-fuzzy inferential systems (ANFIS) presented an approach to estimating the average indoor temperature in the building environment. However, the restriction on robustness limited the energy efficiency and indoor comfort ratio. An accurate and robust prediction model is proposed in this paper. Comparing to the previous unphysical rules based ANFIS prediction model, the improvement of the physical rules based ANFIS prediction model will be presented and the reason of better performance of this new model will be discussed. Three performance measures are using in evaluating the proposed prediction model.
Research of the Fins Thickness Based on 600MW Supercritical Boiler Water-Wall Cross-Section Temperature Distribution
Authors: Su Yong Jun , Yang Jun Bao
Published: June 2012

The finite element model of supercritical boiler water-wall has been established and the ANSYS10.0 was used to simulate cross-section temperature distribution. The simulation result shows that fin-point is the highest temperature on the whole water-wall cross-section. As the fins thickness changed, fin-point temperature has a optimal value；Basing on some 600MW supercritical boiler, it has an optimal value when the fins thickness ranged from 7mm to 9mm.
Research on Heat Transfer and Environmental Impact of Horizontal Ground Heat Exchangers in Multi-Grooves
Authors: Yu Zhong Yi , Chen Yan Hua , Zhou Min Rui , Lei Jian Ping
Published: June 2012

This paper progresses to dynamically simulate and study the heat transfer process of horizontal ground heat exchangers in the multi-grooves by the use of numerical simulation based on the layout and heat extraction or rejection conditions of horizontal ground heat exchangers under the artificial lake. Effect of buried pipe type and groove spacing on the heat exchanger process is analyzed in detail. The influence of annual average water temperature change on the surrounding environment is evaluated with the introduction of parameters including summer weekly average maximum temperature rise and winter weekly average maximum temperature drop, in which can take the technical supports for the design of horizontal ground source heat pump system.
Study on Thermal Management for Cooling System of Aero-Piston Engine
Authors: Ji Fen Zhu , Zhou Xiao Xu , Tian Mi
Published: June 2012

A model of thermal management for cooling system of aero-piston engine was presented in this study. The models of main parts in this system were also founded. Based on the measured value of temperature and pressure in the cylinder, the heat transfer coefficient between gas-fired and the cylinder wall was calculated by using the empirical formula. A heat transfer boundary condition between fins and cooling air was determined according to various Reynolds number of the air flow. Moreover, the method of finite element analysis was utilized to calculate the temperature of cylinder block. In the specified working condition of some two-stroke piston engine used in the unmanned aerial vehicle (UAV), the calculation and analysis were made to study on the effect of aircrew speed and flight height on the cylinder block temperature, as well as the effect of cylinder block temperature on airscrew speed by the thermal management model. The calculation results show that, as the flight height rises, the cylinder block temperature increases accordingly when engine power and airscrew speeds are kept constant; however, at the same height, the higher the airscrew speed is, the lower cylinder block temperature will be. The cylinder block temperature should be kept stable by regulating the airscrew speed.
Effect of Initial Grid's Size in Thermal Diffusion Simulation
Authors: Ma Jin Rong , Guo Ya Qiong
Published: June 2012

The thermal diffusion similitude should be well considered during the numerical simulating of its distribution in power plants or nuclear power stations. The distribution near the waterspout is well related to the initial grid’s size. The bigger the initial grid is, the faster the thermal diffusion. Reasonable initial grid should be related to thermal discharge and flow velocity. Five different grid’s sizes are adopted to simulate the constant diffusion phenomenon in a rectangle water channel, the currents near the waterspout, the thermal diffusion near or away from the waterspout are discussed in this paper, and a rational size of initial grid is proposed to relative researchers.
Analysis on Abnormal Rejects Discharge of a Medium Speed Pulverizer
Authors: Zhao Zhen Ning , Zhang Qing Feng , Ying Wei
Published: June 2012

A series of abnormal phenomena emerging in normal operation conditions of the medium speed pulverizers in a 600 MW unit are introduced. The effects of the primary air (PA) mass flow and nozzle ring passage area on the pulverizer rejects (PRs) discharge are analyzed. The results indicate that the root cause of all these abnormal phenomena is the lower nozzle PA velocity led by the narrowed nozzle passage area during the nozzle ring reformation. The problem is solved by changing the nozzle ring back to the original one. The experiences in this document can provide evidence and reference for pulverizer operation adjustment and PA nozzle ring reformation design.
Analysis of Two-Dimensional and Three-Dimensional Simulation of the Disc Eddy Current Braking Device
Authors: Ying Zhi Ding , Fang Yu Long , Xu Xin Fu , Sun Wei , Chu Yang
Published: June 2012

To analyze the variation of electromagnetic field distribution, a mathematical model of the eddy current brake (ECB) is established and the two-dimensional simulation and three-dimensional simulation are comparatively analyzed. Then the curves of the braking torque of the ECB at different speeds are obtained by the simulations. The characteristics of two-dimensional and three-dimensional simulation of the electromagnetic field of the ECB are summarized by contrasted comparative curves between simulation date and test date. The analysis is helpful to optimizing the application of electromagnetism by using software.
Applications of a Coupled Methodology to the Wind Turbine Airfoils
Authors: Chen Qing Yuan , Guo Feng Lin , Xu Jin Quan
Published: June 2012

In this study, a coupled methodology is proposed for the aerodynamic behavior of wind turbine airfoils. The idea is to combine a Navier-Stokes solver with a free vortex model. The zone for the calculation of CFD is confined to the surrounding of the airfoil, whilst the free vortex model accounts for the far field of the airfoil. The flow around the airfoil is assumed to be two-dimensional (2D) incompressible fully turbulent flow, which is modeled by two equation turbulence models. The computed aerodynamic coefficients are presented for two wind turbine airfoils and compared with wind tunnel data.
Crank Event Based Fuel Injection and Spark Ignition Timing Control Strategy for SI Engines
Authors: Yao Dong Wei , Wu Feng , Xie Huang , Zhang Yong Guang
Published: June 2012

For the controlled gasoline engine MR479Q, the crank speed, camshaft position, fuel injection, spark ignition timing signals and their relationships under control mode of group ignition and fuel sequential injection were deeply analyzed, then an electronic control unit (ECU) hardware platform solution based on Freescale 16-bit microcontroller MC9S12XEP100 was given out. Taking advantages of the hardware platform itself, a crank event based fuel injection and spark ignition timing control strategy was proposed to enhance traditional fuel injection and ignition reliability. Fuel pulse width, ignition coil dwell time and spark advance control under different engine operating conditions were then designed in detail respectively. The bench test results show that, the fuel injection and spark ignition timing control signals of ECU are accurate and stable enough under steady operating conditions, even under transient operating conditions when step disturbance exists in throttle opening, the fuel pulse width, dwell time and spark advance are also delivered correctly and reliably. The strategy is feasible enough to accomplish precise control of fuel injection and spark ignition.