bluuebunny/crossref_metadata_2025 huggingface dataset:
The New Agegraphic Dark Energy: Testing with Observational Hubble Parameter
Authors: Li Sui Yuan , Hu Ming
Published: June 2012

In this article, we use observations of the Hubble parameter from the differential ages of passively evolving galaxies to constrain the New Agegraphic Dark Energy(NADE) model. The NADE is a single-parameter model. The constraint giving the best fit of the parameter is n=2.89. It is in consistent with other analyses by Hao Wei et al.( Wei, H 2007).
The Quantum Effect of Massive Particles via Tunneling from the Einsein-Born-Infeld Black Hole
Authors: Jiang Qing Quan
Published: June 2012

Hawking radiation of massive particles via tunneling from the stationary axial symmetric Einsein-Born-Infeld black hole is studied. The result shows that, when self-gravitation interaction is considered, the exact spectrum is not precisely thermal, but satisfies the unitary theory. In special case, we also reduce the result to obtain the Hawking effect via tunneling from the Schwarzschild, Kerr and Kerr-Newman black hole.
A New Method for Improving the Capacity of Li1+xV3O8 in Rechargeable Lithium Batteries
Authors: Lu Dao Rong , Li Zhi Xian , Xie Ying Chun
Published: June 2012

A new method was used to synthesize the cathode material Li1+xV3O8, and it simplified the process of preparing and shortened the time of reaction in comparison with previous Sol-gel method with the citric acid. The characteristics of Li1+xV3O8 were investigated by X-ray diffraction, thermogravimetry and differential thermal analysis, and transmission electron microscopy, which showed the material Li1+xV3O8 with a good thermal stability had been obtained via the new method. The electrochemical performance of Li1+xV3O8 was measured, which indicated that the material obtained had a remarkable discharge capacity of 380mAh/g and a good cycle performance.
Kinetic Consideration of Energy Storage Process for Polyaniline in Salt Solutions
Authors: Jiang Long Fei , Song Ye , Qi Wei Xing , Lu Chao , Zhu Xu Fei
Published: June 2012

The electrochemical performance of polyaniline (PANI)/stainless steel electrodes prepared in H2SO4 and p-toluene sulfonic acid (p-TSA) using potentiodynamic method were investigated in corresponding acids and three kinds of sodium salts, respectively, by cyclic voltammetry, galvanostatic charge-discharge cycling and electrochemical impedance spectroscopy (EIS). It is concluded that the counter anion of acid employed in the electropolymerization plays a key role in the free volume of PANI. The kinetic parameters of PANI are strongly influenced by the free volume both in acid and in salt solutions. In addition, the utilizing of salt solution is beneficial to the kinetic analysis of the energy-storage process of PANI, although the capacitance of PANI in salt solution decays on cycling due to the lack of protons.
Piping Stress Analysis of Low Temperature Storage Tank for LNG
Authors: Xing Huai Nian , Zhang Xiao Peng , Liu Zeng Li , Jin Li Qiang
Published: June 2012

Finite element method has been used to analysis the stress of inner pipes of low temperature storage tank for LNG caused by temperature, pressure and weight. Filling liquid state, storing liquid state and unloading liquid state are considered in this paper. The results show that the stress of the top pipes would be the largest under filling liquid state which is only little larger than storing liquid state. The stress of the bottom pipes would be the largest under storing liquid state. The deformation of the inner container of the tank would influence the stress distribution. Choosing a flexible structure as designing the bottom pipes is reasonable.
Preparation of Delithiated Cathode Materials of Li-Ion Battery by Chemical Extraction Employing Na2S2O8
Authors: Yan Shi Jian , Zhang Min Gang , Chai Yue Sheng , Tian Wen Huai
Published: June 2012

A method of conventional chemical reaction to prepare delithiated cathode materials of Li-ion battery has been introduced. The cathode material of Li-ion battery was mixed with oxidizing agent Na2S2O8 in water, and the liquid was stirred continuously to make the chemical reaction proceed sufficiently, then the reaction product was filtered, finally the insoluble delithiated cathode material was obtained. A series of tests were conducted to verify the composition, crystal structure and electrochemical property of the delithiated cathode materials were all desirable. This method overcomes the shortcomings of battery charging preparation and chemical extraction preparation employing other oxidizing agents.
Research on TRL Assessment System Supporting Energy Storage in Micro Grid
Authors: Li Gang , Liu Zi Fa , Yang Jia Ming
Published: June 2012

As part of micro grid, energy storage system provides an essential part in smart grid, it enables renewable, and is ready to be deployed today. This paper introduces the technology readiness levels (TRL), which can divide the investment process of energy storage into several phases, optimize the investment timing, and reduce the technology investment risk. This paper is aiming to give suggestion on the issues of energy storage system’s implementation process, and we analysis the feasibility of the standard in theory and verify it in a case study.
The Split of Horizontal Semi-Annular Flow at a Novel T-Junction Type Distributor
Authors: Liang Fa Chun , Chen Jing , Cao Xue Wen , Liu De Xu
Published: June 2012

Extensive experiments have been carried out at an air-water loop to study the phase splitting characteristics of semi-annular flow in a new type distributor. The distributor composes eight small holes with a diameter of 3.5mm on the pipe wall and an annular chamber mounted outside of these holes. The gas-liquid mixture extracted from the holes is collected in the annular chamber and enters branch arm ultimately. Compared with conventional T-junction, the branch quality can maintain unchanged over a wide range of mass extraction rates. A model is developed to predict the phase separation in dividing semi-annular flow. The model simulation results were compared with experimental measurements, and there is reasonable agreement between model prediction and measured data. According to this model, the desired branch quality may be achieved by changing the ratio of gas flow area and liquid flow area.
A Method Approaching Mirror Boundary Condition in SPH Simulation
Authors: Jin Feng , Wan Chao , Liu Hu Ying
Published: June 2012

A method approaching mirror boundary condition for smoothed particle hydrodynamics (SPH) method is presented. The virtual particle is generated through the nearest boundary particle of the flow particle. The operation is relatively simple and convenient and the applicability to the complexity boundaries can be markedly enhanced. The two dimensional non-linear sloshing is simulated with the new boundary condition. The results are in good agreement with the mirror boundary condition and the boundary force condition dada. It shows that this boundary condition can work well for SPH models.
Approach to some Properties of Parallel to Wall Shear Flow and its Application
Authors: Liu Zhao Cun , Fan Wei Jia , Wang Ping Yi , Xv Xiang Zhou
Published: June 2012

Some properties of two dimensional open channel flow were studied. Energy distribution was calculated to show energy exchanging relationship between the mean flow and the fluctuating flow. Viscous dissipative energy of mean flow, the energy of fluctuating flow and the energy of fluctuating flow taking from the mean flow were calculated. The energy spectrum was explored. The mechanism of two dimensional parallel to wall shear flow were probed to show that not only the energy transfer relates different structures corresponding to different levels of turbulent exciting but also the energy dissipating and diffusing closely connect with resonant vibration and frequency-locking. On the basis of flowing structures, the results applying to waterway regulating was discussed.
Study on the Flow Field in Membrane Bioreactor Research by Using PIV
Authors: Qiao Bo Bo , Tian Rui , Li Chun Li , Li Rui Fang , Dong Xue Qing , Wen Jia Long
Published: June 2012

Membrane bioreactor flow field distribution directly affect effective control of the membrane pollution,and affect the membrane flux greatly. The experiments of membrane bioreactor liquid are measured by using PIV that the measurement areas include membrane bioreactor upper, middle and lower. The experimental data obtained velocity field information through the PIV software analysis. The experimental result indicates that middle of the membrane bioreactor flow field is the most unstable. The experimental measurement result provide membrane bioreactor structure the optimized design, effective control of membrane pollution and raise the membrane flux.
ESP Impeller Defect Inspecting Based on the Fluid Energy Analysis Method
Authors: Shen Yue , Zhang Ling Tan , Zhang Heng , Cui Shi Li
Published: June 2012

The primary energy losses of electric submersible pump (ESP) are waterpower loss and volumetric loss. Owing to the limit of current casting technique of the ESP impeller, some fractions of casting residua will be settled in the flow passage of impeller and cause local jam-up in the flow passage, which will increase additional waterpower loss and reduce the pump efficiency. Because of the complicated structure of ESP impeller, conventional nondestructive testing (NDT) is difficult to inspect the defects fast and efficiently. Fluid energy analysis method based on the boundary layer theory and the flow resistance theory analyzes the fluid kinetic energy loss caused by obstacles in the flow passage of impeller and the change of flow rate caused by the change of flow resistance. Based on the similarity principle of fluid movement, abnormal change of waterpower construction in flow passage of impeller can be reflected by measuring and analyzing the impact pressure change generated by flow rate of each flow passage using air as flow medium. The theoretic analysis and experimental results show that this method can identify the defective impeller quickly, efficiently and correctly and will be of some revelatory action on measuring the waterpower structure change of complicated impeller machinery with small size.
Computational Fluid Dynamics Simulation about Comparison of Different Forms of Return Air in a Small Cold Store
Authors: Tang Yi , Xie Jing , Wang Jin Feng , Miao Chen , Zheng Yi
Published: June 2012

The quantity of the cold store in our country has been rapidly rising since the 1990s, however, the flow field in the cold store is difficult to obtain accurately by experiments. With reference to the experiences in previous numerical simulations in this paper, CFD is used for analyzing two forms of return air in the cold store with the Finite Volume Methods and the SIMPLE Revised. As a result, Combining with the non-equilibrium wall function, it is found that taking the way of return air on both sides of the fan is more reasonable and the cooling consumption of the empty cold store can be saved before the products enter the cold store. Furthermore, the numerical simulation results can provide reference for choosing fans in the small cold store.
The Integrated Analysis of Economy and Safety on SOFA Running Mode of a 600MWe Boiler
Authors: Yang Jian Guo , Yang Yang , Zhang Qing Fu , Zhao Hong
Published: June 2012

The application of separated over-fire air (SOFA) in coal-fired boiler results in significant decrease of NOx emission but increases the trend of fireside water wall high temperature corrosion and incomplete combustion of pulverized coal. In order to meet the balance between low NOx emission and high boiler thermal efficiency, the main factors of air staging including SOFA flow, SOFA jet velocity and SOFA jet height were experimented on a 600MWe boiler. At the same time, the main components of flue gas beside the water wall were measured to evaluate the trend of high temperature corrosion. By comprehensive analysis, the optimum running mode of SOFA is concluded: (a) 75% of normal SOFA flow is suggested to reduce the trend of high temperature corrosion; (b) higher SOFA velocity is better for higher boiler thermal efficiency; (c) higher SOFA jet height is beneficial to the reduction of NOx emission.
Research on Dead-End Tunneling Ventilation Control System
Authors: Wang Shu Fang , Yang Zhi Yong , Li Ming Hai
Published: June 2012

On the basis of analysis of ventilation requirement and CO concentration distribution character in dead-end tunneling, this paper designed the ventilation equipment layout. Furthermore, a control strategy which includes normal ventilation mode and gun smoke discharging mode is established. In view of expert experience and numerical simulation results dead-end tunneling, fuzzy control is adopted to deal with this problem. Control rules principle is described in detail. Applying direct torque speed adjustment mode, an experimental system is designed and implemented. Partial experimental results show that gun smoke emission process is fast in order to increase efficiency, while normal ventilation mode is adjustable air flow for energy conservation.
Simulation Calculation of Spiral Condenser about Refrigerant System
Authors: Bai Jing
Published: June 2012

This paper establish a simulation program about the spiral condenser based on theoretical behavior of thermal parameters used R134a as refrigerant, analysis the influence of heat transfer area on refrigerant performance, and calculate best length of condenser heat transfer tube. The results show that the tread of coefficient of performance(COP) and cooling capacity of the system is similar along with the heat transfer tube length, and the research for the optimization design about spiral condenser heat exchanger provides the theoretical support.
Study on Adsorption Desiccant Based Hybrid Air Conditioning System
Authors: He Zhao Hong , Huang Hong Yu , Lin Zhi Xian , Yuan Hao Ran , Kobayashi Noriyuki , Guo Hua Fang , Chen Yong
Published: June 2012

The desiccant based hybrid air conditioning system can control temperature and humidity separately, which consists of adsorption desiccant system and compression type refrigeration system. The adsorption desiccant system obtains the moisture power, and the compression type refrigeration can obtain sensible heat load. Generally, the regenerated energy consumption of the desiccant wheel is very large in the total energy consumption, using electric power, waste heat or renewable energy (solar etc). Heat recovery from the condenser considered as only regenerated energy in the new type adsorption desiccant based hybrid air conditioning system is proposed and discussed in this paper. This method can reduce much energy consumption, and make the air conditioning system structure simple.
The Discussion of Engineering Designing of Radiant Cooling System Based on Evaporative Cooling
Authors: Huang Xiang , Zheng Xiao Li , Yin Qing Hai
Published: June 2012

Comparing the calculated results based on different AUST, point out some problems in current design process, the calculation shows that the increase of AUST leads to greater initial cost. To avoid this error, summarize the relationship of radiant cooling ability between surface temperatures of radiant floor, indoor temperature, pipe space and average temperature of water, find out the performance parameters of radiant plate. Then expounds a specific design steps, provide reference for engineering designing.
Diffusion Characteristics of Indoor Particles in Different Ventilation Strategies Room
Authors: Lu Yang , Qu Zhen Ping , Wu Wen Tao , Yoshino Hiroshi
Published: June 2012

Since indoor particles accumulate on the floors easily, there is a high possibility of allergic reactions in child whose breathing zone is near the floor surface. Ventilation is one of the best ways to remove indoor particles. The aim of this study is to clarify the diffusion characteristics of indoor particles in different ventilation strategies room by experiments and CFD. Comparison of the number of particle in experimental monitoring point shows that the number of particle in the ceiling exhaust was a little higher than the slit exhaust ventilation strategy. CFD simulations concerning diffusion fields completed. From the data we can conclude that slit exhaust ventilation strategy will produce less indoor particles in the room to compare ceiling exhaust ventilation strategy.
Application of Coordinated Regulation in Ensuring the Sustainability of China’s Power Sector
Authors: Yin Xin Zhe , Huang Shou Jun , Tang Song Lin , Ren Yu Long
Published: June 2012

A new methodology-coordinated electricity regulation is presented with coordination theory and multi-principal theory. Then a new coordinated regulation scheme is designed based on the new methodology and the status quo of China’s electricity regulation. At last, paper gives further recommends on improving China’s electricity regulation, such as establishing and ensuring the competitive electricity market, protecting environment, promoting energy efficiency, protecting social interests, etc.
Design and Test of Saturable Reactor
Authors: Song Meng , Ren Li , Cao Kun Nan , Xu Ying , Dong Hong Da , Shen Shi Feng , Wang Da Da , Shi Jing , Tang Yue Jin
Published: June 2012

With the expansion of the grid, continuous reactive power compensation is vital for efficient operation of long transmission power lines or cables. Yunnan Electric Power Grid is planning to development saturable reactors for 500 kV long distance AC transmission lines. As the first stage of the development plan, the appropriate saturable reactor structure should be presented and verified by experiment. In this paper, different ferromagnetic materials, core structures and winding arrangements of saturable reactors are analyzed. Then, appropriate saturable reactor structure is determined by simulating calculation. Based on that, a small-scale prototype is designed and fabricated. The experimental results show that it can obtain a continuous controllable reactive power output.
Grounding System Analysis and Design Considerations for Large Hydroelectric Power Plant
Authors: Li Ye Xu , Dawalibi Farid Paul , Ma Jin Xi
Published: June 2012

Grounding system analysis and design considerations for large hydroelectric power plant are analyzed and discussed in this paper. The main work that has been carried out includes: constructing adequate soil structures and analyzing the effects of the finite heterogeneous soil structure, the modeled river length and the water reservoir levels; conducting accurate fault current distribution calculations and studying the influence of circulating current on the touch and step voltages. The paper discusses the design of the grounding system and its safety performance while considering the impact of the circulating current and inductive coupling from cables and long parallel conductors inside the plant. Two practical examples have been provided in this paper. Furthermore, the paper demonstrates the effectiveness of using heterogeneous finite soil volumes to analyze large hydroelectric power stations and confirms that accurate grounding software packages are required to account for large circulating currents within the ground conductors and strong inductive coupling that exists between metallic elements within the substation. The results and discussions presented here can be used as a reference for engineers to analyze extensive grounding systems and to design appropriate grounding systems for large hydroelectric power plant.
Modeling Research of Background Noise in Low-Voltage Power Line Communication Channel
Authors: Guo Hao Kun , Wu Jun Ji , Ying Zhan Feng
Published: June 2012

Background noise interference is one of the most important factors for low-voltage power line communication’s reliability. By analyzing the background noise of low-voltage power line communication’s channel, the background noise’s measuring circuit is set up and the AR model of the measured background noise is established. Both of them are respectively using singular value decomposition and Levinson-Durbin (LD) recursive method to calculate the AR model’s parameters and a comparative analysis of the simulation is made. The results induct: parameters acquired from the methods of singular value decomposition and LD recursive method are feasible, the parameter model from singular value decomposition is relatively complex, but extremely accurate, which is suitable for the off-line calculation and analysis of the low-voltage power line’s background noise; the parameter model from LD recursive method is very simple, but has a greater loss of accuracy, fitting for online quickly generation of the low-voltage power line’s background noise.
Overview on Distribution Network Reconfiguration Optimization Algorithm
Authors: Li Chuan Jian , Yu Nan Hua , Chen Hui , Zheng Wen Jie
Published: June 2012

With the increasing demands are beyond the capacity of the power generation and the progressive demands for higher power quality, it requires for further study on distribution system reconfiguration. This paper describes the distribution network reconfiguration algorithms in detail. The advantages and disadvantages of the various algorithms and improvement are also analyzed in this paper. At the end of the paper, the development directions of distribution network reconfiguration are discussed.
Power Factor Optimization of Distributed Generations in Distribution Networks Based on Improved Particle Swarm Optimization Method
Authors: Li Cheng Xi , Yan Wen Jun , Yang Qiang
Published: June 2012

The gradually extensive penetration of small-scale distributed renewable generators in existing medium-voltage power distribution networks highlights many technical challenges which call for urgent solutions from power utilities. This paper attempts to optimize the power factor of distributed generators (DGs) integrated in distribution networks and presents a novel algorithmic solution. With the aim of minimizing power loss whilst maintaining the node voltage, the problem is formulated with a mathematical model elaborating the DGs and a set of constraints in distribution networks and addressed through adopting an extended particle swarm optimization (PSO) approach. The suggested algorithm is assessed through numerical simulation experiments with the IEEE 33-bus system and the outcome shows that the optimization algorithm can effectively reduce the power loss and promote the node voltages across the overall distribution network.
Research on Multi-Objective Transmission Planning in Electricity Markets
Authors: Liu Yang , Liu Xu , Cui Feng Xian , Gao Liang
Published: June 2012

Abstract. Transmission planning is a complex optimization problem with multiple deciding variables and restrictions. The mathematical model is non-linear, discrete, multi-objective and dynamic. It becomes complicated as the system grows. So the algorithm adopted affects the results of planning directly. In this paper, a fast non-dominated sorting genetic algorithm (NSGA-II) is employed. The results indicate that NSGA-II has some advantages compared to the traditional genetic algorithms. In transmission planning, NSGA-II is feasible, flexible and effective.
Analysis and Control of Induced Electromotive Force in Control Cable
Authors: Zheng Xian Feng , Dong Yun Hua , Zhang Jing
Published: June 2012

Causes of induced electromotive force (emf) in other circuit are analyzed when a single loop in control cable is connected to an alternating voltage source in this paper. The size of induced emf and its influence factors are discussed. Based on theoretical analysis and test, the control measures of induced emf in control cable are put forward.
Study on the Wave Deformation of a Traveling Wave Piezoelectric Stator Using Composite Transducer
Authors: Liu Ying Xiang , Feng Pei Lian , Chen Wei Shan , Liu Jun Kao
Published: June 2012

In a previous study, the authors have presented and developed a cylindrical traveling wave piezoelectric motor using a composite transducer. This study focuses the research on the wave deformation problems in the proposed stator. Firstly, the standing wave excited by the longitudinal vibration of the transducer is analyzed, and the vibration amplitudes of particles on the driving teeth are extracted to present the objective wave shape. Then, the wave deformation of the standing wave excited by the bending vibration of the transducer is analyzed. Finally, the longitudinal and bending PZT are excited together to gain a flexural traveling wave in the stator, and the vibration amplitude distributions in radial and circumferential directions are gained. Study result indicates that there are obvious deformations on the two standing waves, which cause the motion trajectories of the surface particles are inconsistent.
A New Method to Discriminate the Inrush Current Based on Prony Analysis
Authors: Huang Shao Feng , Shen Hong Ming , Wang Jia
Published: June 2012

The main problem for transformer protection is still how to identify inrush current. The inrush current is likely to occur when the transformer is closed with no-load or when the voltage recovers after fault. False operation may take place for the inrush current is big enough. This paper takes prony analysis as tool to fit the current waveform, and finds that there are two attenuation factors in asymmetrical inrush current’s aperiodic component, one attenuation factor in fault current’s aperiodic component, zero attenuation factor in symmetrical inrush current’s aperiodic component. It is necessary to point out that the two attenuation factors in asymmetrical inrush current are very different in value. Thus, it is possible to identify the inrush current through the number of aperiodic component’s attenuation factor. A large number of MATLAB simulation results prove the method.
Influence of Magnetron Sputtering Method on Cyclic Performance of Tin Film Anodes
Authors: Zhao Ling Zhi , Niu Qiao Li , He Miao , Su Shi Chen , Ru Qiang , Hou Xian Hua
Published: June 2012

Tin thin films on Cu foil substrates as the anodes of lithium ion battery were prepared by direct current (DC) and radio frequency (RF) magnetron sputtering (MS), respectively. The surface morphology and cyclic performance of the films were characterized by atomic force microscope (AFM), scanning electron microscopy (SEM), inductively coupled plasma atomic emission spectrometry (ICP) and galvanostatic charge/discharge (GC) measurements. It is found that the cyclic performance of Sn film prepared by RFMS as anode of lithium ion battery is far better than that prepared DCMS. The discharge capacity of the film prepared by DCMS changes from 748 mAh/g of 1st cycle to 99 mAh/g of 30th cycle. Nevertheless, the discharge capacity of the film prepared by RFMS changes from 653 mAh/g of 1st cycle to 454 mAh/g of 30th cycle. The better performance of the film prepared by RFMS is ascribed to the retardation of the bulk tin cracking from volume change during lithium intercalation and de-intercalation, which avoids the pulverization of tin.
Study of an Inorganic Ion Exchanger Mg2.5Ti(PO4)3
Authors: Jiang Jin He
Published: June 2012

New complex inorganic ion exchanger Mg2.5Ti(PO4)3 is synthesized. Chemical composition, structure and some related properties and complex mechanism of this ion exchanger are investigated by electron microscopic, X-ray diffraction and chemical methods. Results of column test indicated, that the exchange capacity obtained from tests for Li+ in 0.1mol /L HNO3 solution is 9.0mmol/g.
The Amperometric NOx Sensors’ Electrode Polarization and its Effect on the Offset
Authors: Li Le Qing , Tang Ling
Published: June 2012

Amperometric NOx sensors have been developed for the applications of on-board vehicle exhaust sensing for diesel powertrains to meet the strict government emission regulations in North America and Europe. The sensing mechanism of these sensors to NOx was studied along with several noise factors that affect the NOx output. It was found that cross sensitivity to oxygen may result in an increased offset. The results from this study indicate that polarization of one or more of the electrodes is a major factor affecting the magnitude of the offset.
A PLC Based Real Time Simulation and Test Strategy for the Industrial Process Control
Authors: Chang Jyh Ming , Chen Meng Jen , Wu Yu Chi
Published: June 2012

A PLC (Programmable Logic Controller) based real time simulation and test strategy for the industrial process control has been proposed. Different stages of system design and test are achieved to fulfill requirements of the industrial process control. The on-line and real time simulation system provides a platform for verifying accuracy and reliability of user control codes. It is not only for normal operations, but also for abnormal sequence inspections. According to the experience of a real industrial project, it is proved to shorten a large amount of commissioning and debugging time for implementing a control system. By the flexibility and operability of a HMI console, training measures can be put into practice in the dedicated simulation environment instead. Risks are considerably diminished and the efficiency of project development is improved as well.
Analysis and Simulation of Wireless Power Transfer System Based on Magnetic Resonances
Authors: Qu Mei Ling , Shi Xin Zhi , Qi Chang , Wang Gao Feng
Published: June 2012

Wireless power transfer brings the possibility of connector-free for electric devices. Because there is no electric connection between power source and load, the system employs wireless power transfer based on magnetic resonance becomes safer, more convenient and more reliable. The wireless power transfer system of four-coils based on magnetic resonances is analyzed, including phenomenon of frequency splitting, effect of the angle between the source coil and the device coil, and effect of external objects. Simulation results are presented in this paper.
Optimization of Combine Heat Pump and Cogeneration System under Alternative Performance Criteria
Authors: Zhao Qi , Tan Yu Fei , Wang Chen
Published: June 2012

In this study, a performance analysis based on alternative performance criteria has been performed for a reversible Carnot and heat pump cycle, modiﬁed for cogeneration, with external irreversibilities. The optimum values of the design parameters of the new cogeneration cycle were determined for different criteria. In this context, the effects of design parameters on the exergetic performance are investigated, and the results are discussed. The obtained results may guide towards a more realistic criterion for actual combine heat pump and cogeneration plants.
Harvesting Human Biomechanical Energy to Power Portable Electronics
Authors: Xie Long Han , Du Ru Xu
Published: June 2012

It is known that human body contains rich chemical energy, part of which is converted to mechanical energy up to 200W, especially when human in walking, so human body is an ideal sustainable energy resource for portable electronic devices. The motion pattern of human movement in normal walking is studied, showing that the arm swinging, knee motion and hip motion can be approximated as sinusoidal functions with relatively large amplitude. In order to harvest such human motion, several methods are investigated, including pendulum, translational spring and torsion spring, which can also be mathematically formatted as second order differential equation with damped item. This paper also gives a typical device to harvest human motion: a novel energy harvester which directly converts human motion to electricity based on electromagnetic induction. Detail structures of the harvesting device are illustrated with mathematical analysis. Simulation studies are also made.
Investigation of DC Vacuum Arc Interruption Ability with Combined Axial and Radial Magnetic Field
Authors: Al Dweikat Mohmmad , Huang Yu Long , Shen Xiao Lin , Liu Wei Dong
Published: June 2012

DC Vacuum Circuit Breakers based arc control has been a major topic in the last few decades. Understanding vacuum arc (VA) gives the ability to improve vacuum circuit breakers capacity. In this paper, the interaction of a DC vacuum arc with a combined Axial-Radial magnetic field was investigated. The proposed system contains an external coil to produce axial magnetic field (AMF) across the vacuum chamber. The vacuum interrupter (VI) contacts were assumed to be untreated radial magnetic field (RMF) contacts. For this purpose, Finite Element Method (FEM) based Multiphysics simulation of the immerging magnetic field influence on the VA is presented. The simulation shown the ability of the presented system to deflect high DC vacuum arc, also reveals that the vacuum arc interruption capability increases with the rise of the axial component of the magnetic field. Simulation results shown that this method can be applied to improve the interruption capability of the VI.
Research on SVPWM Control of Three-Level Inverter
Authors: Wei Hong Li , Chen Zheng , Wei Yong Qing
Published: June 2012

Three-level inverter SVPWM control process and algorithm are detailed analysis in this article, and put forward a new algorithm to reduce the amount of computation, establishment of three-level inverter simulation model, through analysis, validation the based of SVPWM control of three level inverter can overcome many disadvantages of the traditional two level inverter in high power transform, has extensive practical value.
Safety Analysis for Complex Thermal System Based on Sneak Path Technique
Authors: Yao Shou Guang , Wang Gong Li
Published: June 2012

Sneak circuit analysis technique is an important analytical tool that can promote the safety and reliability of the circuit control system. It applied to aerospace control engineering widely now. Comparing a thermal system and electric circuit system, the concept and method of sneak path analysis for complex thermal system are proposed by this paper. And the development and application vista of thermal system sneak path analysis and specific implementation are analysed.
Theory Study on the Geometric Structures and Electronic Properties of PtnN0,±(n=1-5) Clusters
Authors: Zhang Xiu Rong , Yin Lin , Li Wei Jun , Tang Hui Shuai
Published: June 2012

The geometric structures of PtNN0,±clusters are optimized by the B3LYP/LANL2DZ method of density function theory, the ground state structures are obtained, and the electronic structure are studied. The results show: the N atoms gain the charge when the clusters are formed, but some Pt atoms gain the charge and other Pt atoms lose the charge. N atom and Pt atom have internal heterozygous, and the spd hybridized between Pt atoms and N atoms are increasing with cluster s’ sizes.
A Repeated Pulsed High Magnetic Field Generator for Frequency-Tunable Terahertz Sources
Authors: Li Huan , Ding Hong Fa , Xiao Hou Xiu
Published: June 2012

This paper presents a Repeated Pulsed High Magnetic Field (RPHMF) generator for frequency-tunable terahertz sources, which mainly consists of a charging power supply, a capacitor bank, a discharging switch, a bitter magnet and other facilities. The four thyristors (80 mm, 4 kV) in series with a self-supplied gate driver are taken as the discharge switch which can be triggered when the high voltage capacitor C was charged to 300 V. Meanwhile, a bitter magnet with fast heat dissipation was designed and fabricated. According to the experiment, the designed system has a pulse repetition frequency of 0.1 Hz with a maximum magnetic field of 9 T.
Research on Intelligent Control Pattern of the Vehicle Driving Training
Authors: Yao Xin Sheng , Yao Chuan An , Ying Ji Lai , Cao Li Xin
Published: June 2012

with the higher mobility in many developing country, the vehicle volume, vehicle use frequency are rapidly increasing, driving skill training becomes one key factor for vehicle security and use quality. By the comprehensive application of electron, computer, network technology, the supervision, control and guidance can be done to realize the intelligent dynamic management in driving training and standardized test, which promotes the students to obtain the optimal training effect in the possible shortest time, to provide a method to improve the overall driving quality.
Study of Electrical Traction Locomotive Control System Based on Feed-Forward Decoupling Strategy
Authors: Zong Jian , Qian Ping , Ding Xue Feng
Published: June 2012

An asynchronous motor is widely used in traction locomotive system now, AC induction motor is nonlinear, strongly coupled and multivariable system, so it is very difficult to control as a linear system. For this, VVVF(Variable Voltage Variable Frequency) control method adopt in some running traction locomotives, that can reduce over-current with load starting and should be compensated at low frequency. Based on study the Control strategies of locomotives, vector control adopt in most electrical traction locomotive. According to the drawing performance requirements of electrical traction motor, feed-forward decoupling method adopted. Simulation and experiment proved this method can meet the traction locomotive control requirements.
Temperature Control based on Improved Particle Swarm Optimitization to the Adhesive Preparation Processing
Authors: Zhou Guo Xiong , Li Lin , Tang Jun
Published: June 2012

In view of the characteristics of the preparation of an adhesive process which is lengthy, nonlinear, time-varying, big inertia and pure delay, A Proportional-Integral-Derivative (PID) algorithm is proposed based on the improved particle swarm optimization. Because there are drawbacks in the design of PID controller, an improved particle swarm optimization which takes into account a number of performances is propesed to modified parameters of PID controllers. In which the variation of genetic algorithm is introduced to the standard particle swarm optimization algorithm, which can avoid local maximum points, thus the preferable PID controller parameters are easily obtained. Applying the algorithm to the preparation of an adhesive process, the temperature of polymerizing-kettle can be tracked and controlled. Simulation and factual running shows that the algorithm is effective and has excellent performance.
A Review about Condensation Heat Tansfer with Non-Condensable Gases
Authors: Zhang Jun Xia , Gong Bin Yao
Published: June 2012

Non-condenable gases decrease performance of heat transfer by degrading condensation of vapor. Therefore, to comprehend the mechanism that non-condensable gases affect condensation heat transfer is helpful to improve efficiency of heat transfer of devices.At the present work, the update development of experimental and theoretical researches about condensation heat transfer with non-condensable gases were present. These findings report effects of non-condensable gases on parameters, including condensation heat transfer coefficients, flow pattern and wall temperature. Meanwhile, variations of condensation heat transfer in the presence of non-condensable gases with various conditions, involving geometric conditions, flow pattern and species of non-condensable gases. By the contrast, the enhancement of heat transfer of condensation with non-condensable gases should give more concerns.
Experiment Study on Unsteady Frosting of Cryogenic Vertical Plate Surface under Natural Convection Conditions
Authors: Chen Shu Ping , Xie Fu Shou , Yao Shu Ting , Han Hong Yin , Chang Zhi Xin
Published: June 2012

A frosting test bench was designed, and unsteady frosting on vertical plate surface was dynamically described with liquid nitrogen as working medium under natural convection conditions. The variation of frost thickness was analyzed, and the flow state of moist air and temperature distribution near the vertical plate were described. The experimental results show the unsteady frosting of vertical plate surface under natural convection and cryogenic condition actually includes several steps: formation of frost crystals, growth of frost crystals and growth of frost layer. The initial frosting rate is large, but the rate decreases as time goes on until the frost layer thickness is unchanged. Moist air conducts a top-down flow near the vertical plate, and the rest of moist air flows into the main flow. The temperature of moist air decreased systematically along the tangential direction of vertical plate from top to bottom and along the normal direction of vertical plate from far to vertical plate surface.
Effects of Alkaline Earth Metal on Combustion of Pulverized Coal
Authors: Wei Li Hong , Zhang Na , Yang Tian Hua
Published: June 2012

The influences of alkaline earth metal salts (CaO, MgO) on the combustion property of pulverized coal have been studied by thermogravimetric analysis (TGA). It was indicated that CaO and MgO could improve combustion characteristics of pulverized coal. It was demonstrated that the catalysis of CaO and MgO to the pulverized coal combustion was embodied in the enhancement of the emission of volatile matters (VM) from pulverized coal, which reduced the ignition temperature. MgO exhibited remarkably higher catalytic activity than that of CaO for the combustion of fixed carbon. MgO catalytic combustion mechanism for pulverized coal was different from that of CaO.
Heat Transfer Model and Analysis of Oil-Immersed Electrical Transformers with Heat Pipe Radiator
Authors: Li Guang Hua , Liu Hong Lei , Wang De Jian
Published: June 2012

This paper has formulated a heat transfer model for analyzing the cooling properties of a heat pipe cooling device of oil-immersed electrical transformer. Based on the model, the oil temperature field of a 30 KVA oil-immersed transformer has been numerical simulated, and experiments also had been conducted. Results showed that the numerical simulation has good agreement with experiment results. Results also showed that heat pipe radiator is feasible for oil-immersed electrical transformer cooling. The model can be used to analyze the oil temperature distribution properties in an oil-immersed electrical transformer with heat pipe cooling device, and provide theoretical guide for transformer design and improvement.
Inaccuracy of Heat Transfer Characteristics of a Metal Duct Neglecting Heat Radiation Effect in Ambient Air
Authors: Wong King Leung , Chen Wen Lih , Chiu Yung Chin
Published: June 2012

A heat radiation equation contains 4th exponential order of temperature which makes mathematics analysis complicated and time-consumption. Most heat transfer experts and scholars believe, based on their own experiences, that the heat radiation effect can be ignored in situations of small temperature difference between duct surfaces and surroundings. This paper studies in detail for complete heat transfer characteristics of a circular duct with heat radiation effect taken into account. It is found that, in some practical conditions, the heat radiation effect can not be ignored especially in cases of lower ambient convection heat coefficients and larger surface emissivities, as well as the smaller the duct size and/or the greater the duct conductivity and/or internal fluid convection coefficients, even though the temperature-difference between inner and outer fluid-temperatures of duct is low to 1 °C. It is found that the conventional LMTD method (ignoring heat radiation) cannot be applied to calculate the total heat transfer rate of a single-duct heat exchanger located in ambient air, such as condenser and evaporator.
Introduction to Analysis-Simplified and Extension in Momentum, Heat and Mass Transfers
Authors: Duan Yi Wen , Chen Li Ping , Si Qin Da Lai
Published: June 2012

Three transfers have been discussed with analysis-simplified and extension. Some experimental data have been used to regress the main parameters of processes.
Modeling of Boiling Heat Transfer System and Chaos in Microchannel
Authors: Chen Zhi Jing , Luo Xiao Ping
Published: June 2012

A model of boiling heat transfer system was established by introducing disjoining pressure produced by three phase molecular interactions and Lie algebra analysis for a developed bubble in micro channel and simulation of chaotic movement of the obtained interface dynamic system was carried out in this paper. Experiments for 0.6 mm2 mm rectangular micro channel were carried out to obtain the pressure time serials. Power spectrum density analysis for this serials shows that the system is in chaotic state if the frequency is above 7.39Hz.The result indicates that high heat transfer performance of micro channel phase change system may relate to the characteristics of chaos.
On the Estimation of Oxide Scale Growth in T22 Superheater and Reheater Tubes
Authors: Bian Cai Xia , Zhou Ke Yi , Xu Jian Qun
Published: June 2012

In this paper, an iterative procedure was performed for the prediction of scale growth in T22 superheater and reheater tubes, which utilized empirical formulae for oxide-growth kinetics in steam and heat transfer analysis. Several expressions for oxide-growth kinetics and different thermal conductivities of scale were considered in calculations. The results indicate that the expression for oxide-growth kinetics can affect the estimated results significantly, and the thermal conductivity of scale has relatively small influence on the prediction of scale growth, but the influence degree increases with time.
Research on Technology of Blast Furnace Optimization of Operation Principle
Authors: Chi Yan Bin , Yang Shuang Ping , Dong Jie , Zhang Cong Rong
Published: June 2012

By study the development situation of blast furnace smelting in china and the blast furnace operation system and technology, combined with production conditions of JISC BF, based on a large number of the production data, the comparison analysis test on JISC BF operation system and technology was did. Through continuously optimization and practice, the relatively suitable operation system and technology of JISC BF at present was explored, which could reduce the coke ratio into furnace while increasing the coal injection ratio and making great economic effect.
Sensitivity Analysis for Shell-and-Tube Heat Exchangers Based on Entropy Production
Authors: Zhu Guo Rong , Wang Xiao Hua , Huang Hong Biao , Chen Hu
Published: June 2012

In this article, sensitivity analysis was performed using bidirectional single method with shell-and-tube heat exchanger as the basis and the entropy production in the working process of heat exchanger as target, to explore the optimizing direction for heat exchangers with the objective to reduce entropy production. First, the differential element analysis method was used in a case study of the entropy production of the heat transfer process - including the three heat transfer processes of convective heat exchange inside and outside the pipes and heat conduction across the pipe wall and the flow process - the fluid flowing process inside and outside the pipes, and the typical process parameter - dimensionless inlet heat exchange temperature difference, operation parameter - fluid flow rate inside the pipe and structural parameters - the heat transfer pipe inner diameter and length were used as characteristic parameters, to obtain the sensitivity coefficients under the conditions of the example, being respectively 0.95, 0.3, 0.3 and 0.38. The study in this article can provide some support to the energy efficiency evaluation of heat exchangers.
The Simulation of Temperature Control System Heated by Heat Transfer Oil in Vulcanizing Machine Based on Neural Network
Authors: Dong Lin Fu , Wu Jing Jing , Ou Hua Long
Published: June 2012

This paper presents a method of a new system of heating vulcanizing machine by heat transfer oil, it is a system that based on neural network of fuzzy temperature control. One one hand, compared with the traditional PI control of relative ratio, we can make a conclusion that in the heating system of fuzzy control, the heating system robustness could be enhanced. One the other hand, through the analysis of the simulation results, this programme guarantees the stability of heating system and emission the temperature fluctuation which is caused by heating plate. The last but not the least, we can take these advantages and control the system easier.