bluuebunny/crossref_metadata_2025 huggingface dataset:
Review of Mechanical Properties and Durability of PVA Fiber Reinforced Cement Based Composite Materials
Authors: Dai Xiao Bing , Zhang Peng , Gao Ji Xiang
Published: September 2013

As a kind of high performance cement based construction materials, because of good mechanical performance and durability, PVA fiber reinforced cement based materials have been paid more and more attention in the field of civil structure engineering. To grasp the characteristics of PVA fiber reinforced cement based composite materials and promote a better application of PVA fiber reinforced cement based composite in practical engineering, a series of research works on the mechanical properties and durability of PVA fiber reinforced cement based composite were introduced systematically.
Intelligent Electrical Appliance Event Recognition Using Multi-Load Decomposition
Authors: Jiang Lei , Luo Su Huai , Li Jia Ming
Published: September 2013

The management of electricity system in home environments plays an important role in generating energy consumption and improving efficiency of energy usage. At present, nonintrusive appliance load monitoring (NIALM) techniques are the most effective approach for estimating the electrical power consumption of individual appliances. This paper presents our contribution in intelligent electrical appliance decomposition in home environment. It is a modified power appliance disaggregation technique based on power harmonic features and support vector machine (SVM). It has higher recognition accuracy and faster computational speed. The experimental results of the power decomposition technique on real date are presented with promising results.
The Temperature Rise Analysis of the Old Conductors
Authors: Ju Yan Zhong , Wang Xin Ying , Bai Jun Feng , Zhou Wen Bin
Published: September 2013

In order to study the conduction performance of the old transmission lines, we carried out a comparative study by testing the heat dissipation of the old and the new overhead conductors (35 kV aluminium cable steel reinforced (ACSR) lines, LGJ70/10). The temperature variation of two distinct types of lines under the identical current flow was investigated in details theoretically and experimentally. Our extensive experiments show that the temperature rise of old lines is higher about 11% than those of new lines with the same current flow of 255 A. By combining the theoretical analysis and experimental observations, it is concluded that the heat radiated power of the old lines is higher about 46% than that of new lines, such high radiated heat power is the main factor affecting the temperature rise of old lines.
Photovoltaic Power Generation Forecasting Model with Improved Support Vector Machine Regression Based on Rough Set and Similar Day
Authors: Mei Hua Wei , Ma Juan Juan
Published: September 2013

To diminish the effect of photovoltaic (PV) randomization on the power system, combining attribute reduction of rough set with support vector machine (SVM) regression theory, this paper applies SVM regression to directly forecast the output of the PV array, and is based on setting rough set as front-end processor and attribute reduction of historical data. According to the type of forecasting day, this paper selects multiple reasonable similar days (SD) from historical data and uses RS-SVR model to make predication. After repeated accuracy verification, the text used radial basis function as kernel function, and use parametric search and cross-validation method to determine the parameters. Finally, this paper compared average relative error of the RS-SVR forecasting model and SVR forecasting model, and verified that the RS-SVR forecasting model can effectively solve the problem of PV power output forecasting and obtain satisfactory results.
Photovoltaic Driven Liquid Dehumidification Air-Conditioning System
Authors: Li Xiu Wei , Zhang Xiao Song , Cheng Qing
Published: September 2013

Liquid dehumidification air-conditioning system is a promising air-conditioning system as it is environment-friendly, capable of utilizing low grade heat and less dependent on the electric power. However, because of the heat waste, its performance is not yet as competitive as vapour compression system. To improve, a photovoltaic driven system is proposed in this paper: electricity is applied to regenerate desiccant; the electric energy comes from solar power. Performance analysis has been made. The results show the coefficient of performance of the new system is influenced by the concentration of the desiccant and can approach 6 at certain circumstances. It also shows that LiBr solution is more favorable among three common used desiccants. Moreover, this paper presents the new progress of experimental research on this system.
Effect of Pulsed-DC Power on the Zinc Oxide Window Layer of CIGS Solar Cells Deposited by In-Line Sputtering Methods
Authors: Jin Chun Long , Shim Ha Na , Cho Eou Sik , Kwon Sang Jik
Published: September 2013

Zinc oxide (ZnO) thin film was deposited on the glass substrate and cadmium-sulfide (CdS) thin film at room temperature by using an in-line pulsed-DC magnetron sputtering system. The sputtering process was carried out at various pulsed-DC power and radio frequency (RF) power from 400 W to 1 kW. From the thickness of the sputtered ZnO films, it was possible to obtain much higher deposition rate in case of pulsed-DC sputtering than RF sputtering. However, for both pulsed-DC sputtered and RF sputtered ZnO films, the similar results were obtained in case of the energy band gaps and the structural characteristics such as adhesion to CdS. From the results, the ZnO films sputtered by pulsed-DC power are expected to be used in the fabrication process instead of RF power.
Cost of LNG-Fueled Container Vessels
Authors: Li Xin , Sun Yi , Wu Gui Tao
Published: September 2013

Liquefied Natural Gas, compared to conventional ship fuels, offers substantial reduction in NOX, SOX and particulates, but its costs are uncertain. Based on the study jointly made by Germanischer Lloyd and MAN Diesel & Turbo, this paper analyzes cost factors of LNG as fuel for container vessels and calculates cargo space losses resulting from LNG's low density. Calculation results show that cargo space losses are about 1.5%~2% of the total container volume. The results can be used as references for selecting LNG as ship fuel.
Continuous Esterification of n-Butyl Acetate Catalyzed by Ionic Liquid
Authors: Zhong Jing Peng , Huang Bao Hua , Li Zi Jin , Lei Lin
Published: September 2013

An ionic liquid, 2-Pyrrolidonium hydrogen sulfate (IL, [Hnhp]HSO4) together with a rectification column, was applied in continuous preparation of n-butyl acetate (n-BuAc) from n-butanol (n-BuOH) and acetic acid (HAc). [Hnhp]HSO4 was used as a catalyst which showed good activity for the esterification. Optimum conditions were as follows: base fluid n(HAc):n(n-BuOH): n(IL) =6:1:0.3 in reactor at 120 °C, feedstock n(n-BuOH):n(HAc) =1.05:1 by feeding to the reactorat 20 mL·h-1, aqueous reflux 18 mL·h-1 by feeding to the upper segment of the column and reflux ratio 1. During 48 hours of continuous reaction time, n-BuAc content ranged from 97 % to 85 % in the ester phase from overhead liquid-liquid separator and the reactive distillation system could maintain a good balance.
Preparation of Ag Nanoparticles Arrays for Silicon Solar Cells
Authors: Duan Chun Yan , Zhao Xiao Xia , Hu Chang Ji , Lu Dong Liang , Shen Hui
Published: September 2013

Ag nanoparticles arrays were fabricated by self-assembly method to accommodate manufacturing process of traditional silicon solar cells. Surface morphologies of films (5-27.5 nm) after annealing treatment with 260 °C and 400 °C were analyzed. The results showed that annealing temperature has important impact on self-assembled nanoparticles arrays. The tuning function of SiNx dielectric film was also analyzed. The absorption peak generates a redshift with the maximum range about 100 nm in the absorption spectrum, and the peak widths become wider with the increase of thickness of SiNx dielectric film for the same particle size distribution of Ag nanoparticles arrays.
Hydrothermal Modification Effect on the Catalyst for Etherification
Authors: Yan Xi Ming , Ke Ming , Song Zhao Zheng
Published: September 2013

Etherification of isoamylene with methanol has been carried out over the γ-Al2O3/Hβ catalyst in a fixed bed reactor, catalysts were hydrothermal modified at different temperatures and time. The results show that the appropriate loading amount of active component Hβ is 20%; Hydrothermal modification is an effective way to improve the etherification activity, When γ-Al2O3/20%Hβ catalyst was hydrothermal modified at 573K for 3 hours, the isoamylene conversion is the highest, reach up to 51.95%, about 25% higher than the untreated one. From results of BET, XRD, and NH3-TPD characterization can be seen that hydrothermal modification does not change crystalline structure of the catalyst, but specific surface areas decrease together with pore volume and pore size increase, it also reduced the total acid volume of catalyst and improved the surface acid distribution of weak acid and strong acid.
Prediction on China's Energy Demand Based on RBF Neural Network Model
Authors: Feng Xue , Bao Wuyunbilige , Ha Ben
Published: September 2013

Choose factors which influence the energy demand by the method of path analysis, build radial basis function (RBF) neural network model to predict energy demand in China. The RBF neural network is trained with the actual data of the main factors affecting energy demand during 1989-2003 and energy demand during 1993-2007 as learning sample with a good fitting effect. After testing network with the actual data of the main factors affecting energy demand during 2004-2007 and energy demand during 2008-2011, higher prediction accuracy can be obtained. By comparison with the BP network, RBF network prediction model outperforms BP network prediction model, finally RBF network is applied to make prediction of energy consumption for the year 2013-2015.
The Study of Isolated Multi-Input Converter for Green Energy Application
Authors: Juan Yu Lin , He Yi Lin , Chen Chun Ming , Chen Tsair Rong
Published: September 2013

To increase the development and popularization of the Green Energy Generation System (GEGS), this paper aims to develop a multi-input isolated power converter, which could be coordinated on a green-energy-based DC bus. The proposed converter is integrated with commercial grid and batteries, to achieve the grid energy supplement and battery-based emergency backup power supply, respectively. The operational principle of proposed converter is presented, there are three operation mode and its simulation result are illustrated as well.
Numerical Simulation on the Influence of Double-Jet Air Curtain of Smoke-Preventing in Tunnel Fires
Authors: Lv Yuan , Cao Bin , Zhang Li Jing , Tao Gang
Published: September 2013

Select a tunnel in Nanjing as a modeling object and simulate the smoke control capability of the air curtain when nozzle spacing changes.By analysis, the dynamics characteristic with the wider spacing parameters of air curtain nozzle is superior to the narrower one under the same condition.The top of the spacing of the air curtain nozzle is recommended to be 2 to 3 times the width of a single nozzle.
Environmental Impact Evaluation and Economy Analysis of Air-Conditioning Cold and Heat Source Based on TEWI Index
Authors: Liu Chang Rong , Wang Han Qing , Wang Zhi Yong , Zhang Tian Yu
Published: September 2013

TEWI (total equivalent warming impact) index, a comparatively scientific method to evaluate the environmental impact of air-conditioning cold and heat source, is introduced. Taking some engineering in Hunan Province for example, the TEWI analysis was performed on the environmental impact assessment of four air-conditioning cold and heat source plans. Also the first investment and energy consumption were analyzed. The results indicate that: water loop heat pump unit, due to investment recovery period with only 2.9 years and carbon emission reduction up to 22.68%, has significant economy and environmental protection, which is followed by water source heat pump; the screw chilled water units plus gas boiler is poor. Gas direct-fired machine has certain economic advantage, but its environmental performance is general. Among four schemes, the proportion of indirect effects of CO2emissions from fossil fuels used to generate energy to operate the equipment throughout its lifetime are all larger, respectively is 95.1%, 95.2%, 100% and 89.9%. It fully showed the importance of developing clean and renewable energy, reducing energy consumption and increasing performance coefficient of refrigeration and air conditioning device.
Design and its Application of Hybrid Electric Vehicle Driving Status Data Acquisition Terminal
Authors: Yang Jing Feng , Zhang Nan Feng , Li Yong , Xue Yue Ju , Li Ting
Published: September 2013

Based on the technical standards for driving recorder with satellite positioning function, this paper designs a driving status data acquisition terminal for hybrid electric vehicle that could increase the data collection of battery, motor speed, current, power, etc. by the interface technology, and establishes appropriate monitoring platform at the same time. The test results show that, the driving status data acquisition terminal for hybrid electric vehicle meets to the application requirements.
A Fuzzy Logic Controller for Vehicle-Active Suspension Systems
Authors: Sun Yun Quan , Zhao Li Feng , Xiang Wei
Published: September 2013

This paper propose the study of automobile active suspension system for the purpose of improving ride comfort to passengers and simultaneously improving the stability of vehicle by reducing vibration effects on suspension system. A fuzzy-logic-based control for vehicle-active suspension is suggested. The vehicle vibration and disturbance are reduced considerably with a fuzzy logic controller, to enhance comfort in riding faced with uncertain road terrains. A quarter-car active suspension system is controlled to reduce the vertical acceleration, suspension stroke and tire deflection. Simulation studies clearly demonstrate the effectiveness of the fuzzy logic controller for active suspension systems. The performance of the fuzzy logic controller under variations in the suspension component characteristics are also studied and are found to give reasonably good responses.
Charging and Discharging Control of Plug-In Electric Vehicle Based on Immune Clone Algorithm
Authors: Wang Min , Zhang Yang , Li Yong Qing , Zhang Cheng Fei , Yuan Yue
Published: September 2013

When a large scale of plug-in electric vehicles connected to the grid,which will be bound to deteriorate the load curve and will affect the safe and stable operation of the grid without a reasonable means of control. Immune clone algorithm is applied to control the electric vehicles charging and discharging strategy and to develop a optimized scheduling scheme throughout the day. In this way not only can it avoid electric vehicles disorderly charging and discharging disorderly so that to optimize grid load curve, but also can reduce the loss of electric power lines and delay investment.
State of Charge Estimation of Power Lithium-Ion Battery Based on Sliding Mode Observer
Authors: Wu Tie Zhou , Wang Ming Yue , Xiao Qin
Published: September 2013

The study of the application of the sliding mode observer method that estimates the state of charge. Based on the state space model of battery established on the model of improved EMF equivalent circuit, a sliding mode state observer is designed to help improve the jitter problem. Considering the nonlinear terms in the model for the analysis of the stability of the observer and the characteristics of the industry under its derivative, and using Lagrange mean value theory to guarantee the convergence conditions of the observer, the design parameters of the observer can thus be determined .Then, this thesis compares the simulation of this method under Matlab environment with the extended Kalman filter method. The results show that the method has higher estimation accuracy in the case of the same battery modeling errors. Therefore, the SOC estimation of the sliding mode observer can effectively reduce the state of charge estimation error introduced by the model error.
Study on Cutting Tooth Strength of Spiral Drilling Shearer Based on LS-DYNA
Authors: Yang Xu , Wang Zhi Gang , Zhang Lei , Fu Jia Xing
Published: September 2013

In order to study the structure and shape of the three different cross-sectional shapes of the mechanical properties of the teeth, for the cutter during cutting is immediately effective in the external load and characteristics, the use of LS-DYNA established three different shapes of the flexible structure of the cross-sectional tooth physical model, based on kinetic theory building displays constitutive model based IEF coal wall model. Through the next three shapes cutter cutting process simulation, the cut-off stress at the tooth tip curve and its statistical value, different coals under the stress of each cutting tooth size changes and trends; findings for the study of cross-sectional strength of the shape of its teeth, improving coal cut rate, and improve cutter life work provides an important basis. Auger shearer is the selection, design, personalization adapt and use to provide a new means and methods.
Effect on Position of Electromagnetic Stirring on Inclusion Behaviors in Billet
Authors: Zhang Gui Fang , Ding Yue Hua , Shi Zhe
Published: September 2013

A considerable number of research works have been carried out to study the effects of electric current and frequency of Electromagnetic Stirring (EMS) on the quality of cast steels, but there are only a few studies available addressing the effects of EMS location on inclusion removal and steel cleanliness An ideal position of EMS will improve inclusion floatation and separation from liquid steel. However, inappropriate installation will lead to the entrapment of the slag into liquid steel, and impact the quality of cast billet. The current applied for these plant trials was 300A at a frequency of 3Hz,positions form axial centers of EMS to the top of the mold were 450mm, 510mm and 690mm respectively . 130 billets of medium carbon steel were produced and samples were taken for spectral analysis to study the effects of installation location of EMS on steel cleanliness. The experimental results show that the optimum position of EMS should be placed 510mm from the top end of the copper mold when the electrical current is 300A at frequency of 3 Hz. The three parameters of placement of EMS in paper were obtained from the simulation results, and this paper focused mainly on the effect EMS position on inclusion behaviors in billet.
Analytical Fast Pyrolysis of Glucose, Cellubiose and Cellulose: Comparison of the Pyrolytic Product Distribution
Authors: Liao Hang Tao , Zhang Yang , Lu Qiang , Dong Chang Qing
Published: September 2013

Analytical pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) was employed for the fast pyrolysis of glucose, cellubiose and cellulose in this study. The pyrolytic products from the three glucose-based materials were determined and compared to reveal the distribution differences. The results indicated that fast pyrolysis of the three materials obtained similar pyrolytic products, including the anhydrosugars, furans, linear carbonyls and cyclopentanones, but the distribution of the pyrolytic products differed from each other. The cellulose formed more anhydrosugars, but less carbonyls and furans than the glucose and cellubiose. The glycosidic bond of the cellubiose and cellulose would favor the pyrolytic depolymerization reactions to form various anhydrosugars, while inhibit the pyrolytic fragmentation reactions to produce linear carbonyls.
Performance Analyses of Adaptive Access Mechanism in IEEE 802.11 WLANs
Authors: He Shu Qian , Shi Chun , Deng Zheng Jie
Published: September 2013

The performance analyses of adaptive access mechanism have not been studied completely, especially in non-saturation conditions. By using feedback signal of channel, we propose an adaptive access mechanism, which adjusts parameters based on idle slot intervals between two data transmissions. Then, we analyze the network performance of throughput, media access delay and retransmission attempts of packets, which shows some main characteristics of adaptive access mechanism. The simulation results also demonstrate the validity and good scalability of the proposed access mechanism.
Research and Implementation of Intelligent Transportation System at the Intersection Signal Lamp on FPGA
Authors: Zhang Zhao , Fan Di
Published: September 2013

The intelligent transportation system just like an experienced traffic police, using a flexible method to optimize the vehicle system control , and also using the network to control the whole system, grasp the overall distribution of the traffic, which requires the integrated use of modern electronic technology and communication technology and other means to achieve. We use a design of the FPGA system on this topic which is a relatively flexible system. On the software side, using the wide used VHDL hardware description language in the programming, then design a countdown timer and a state transition program and so on, using these to achieve real-time control of an intelligent transportation system at the intersection signal lamp. Finally, using Quartus II software platform process the design files and simulation by Cyclone series.
Contrast of Time-Frequency Analysis Methods and Fusion of Wigner-Ville Distribution and Wavelet Transform
Authors: Zhang Hui Xing , Li Jie , Lin Qi , Qu Jian Zhi , Yang Qi Zheng
Published: September 2013

Time-frequency analysis is a powerful tool for analyzing non-stationary signals, which can describe the signals frequency varying with time and provide us the joint information of time domain and frequency domain of the signal. We use a synthetic signal to realize the time-frequency analysis methods of wavelet transform, S transform and Wigner-Ville distribution. Through comparing and analyzing those time-frequency distributions, we propose a new method of integrating wavelet transform and Wigner-Ville distribution. This new method gives a better result than that of wavelet transform and Wigner-Ville distribution and increases the time-frequency resolution.
Research of Single Component Shock Methods in Wind Turbine Fault Diagnosis
Authors: Jia Ning , Zhang Tian Xia , Li Yuan Sheng , Zhang Tao
Published: September 2013

The structure of the wind turbine generator system is complex and it is difficult to identify the fault signals because of fault frequency aliasing on the vibration characteristics. The wind turbine fault diagnosis method is raised on single component shock to solve the vibration signal feature extraction during the wind turbines operating. Based on the principle of Hilbert envelope demodulation, this envelope demodulation method is presented for the single IMF component which contains shock fault characteristic frequency to solve the possible problem which fault Frequency is difficult to identify when the original signal is directly asked to envelope. This method has been applied and verified when a wind farm CSC-855W wind turbine vibration monitoring device was presented. The results show that compared with the traditional envelope demodulation method, by this method wind turbine fault characteristic can be more effectively and directly extracted and the accuracy of fault diagnosis can be improved. It is of great practical value.
Unbalanced Control Strategy for DFIG Used in Wind Turbines
Authors: Huang Chang Xi , Yang Shu Ying , Chen Liu Wei
Published: September 2013

Unbalanced input voltages would make doubly fed induction generator (DFIG)-based wind turbine operating performance deteriorate, such as shaft tremble, temperature increasing, and so on, even make it cut out of the power grid. Meanwhile, without proper control the power ripples generated from wind turbines may further aggravate power grid. Considering the unbalanced conditions, DFIG was modeled in dual synchronous reference frame (SRF), namely the positive one and the negative one, based on which the dual PI current controllers were designed. To implement the dual current control, the sensing variables were divided into positive and negative sequence components, which were controlled in positive and negative SRF respectively. At the same time, to synchronize with the positive and negative sequence voltage components, a phase latch loop (PLL) control was designed. Experimental results on 11kW DFIG wind turbine test bed validated the designed control system.
A Model of Continuous Optimized Power Flow with DR
Authors: Mao Wen Bo , Wang Ke , Liu Jian Tao
Published: September 2013

A model of continuous optimized power flow (COPF) is proposed, concluding demand response (DR). According to different implementation mechanisms, a series of DR models are built, such as: time of use (TOU), real time price (RTP), critical peak price (CPP), and interruptible load (IL). The influences of these kinds of DR on power system are analyzed, including peak load reduction, cost reduction, and reservation optimization. The results show that: DR can cut the cost, reduce the peak load, and promote the reservation optimization.
A Battery Dynamic Model for the Power System Simulation
Authors: Li Xiao Dong , Dong Zhong Xing , Zong Wei , Liu Zong Qi
Published: September 2013

This paper analyzes the battery dynamic characteristics as well as some existing battery models, then presents a universal battery model applicable to micro-grid simulation. The model is composed of a controlled voltage source in series with a constant resistance .The voltage of the controlled voltage source is a one-to-one correspondence with the state of charge (SOC) of the battery, which can effectively avoid the algebraic loop problem. The parameters of the model can be easily extracted from the battery discharge curve. The simulation results shows that the biggest advantage of this model is that the initial SOC of the battery can be set accordingly, which allows the battery to be charged or discharged from any SOC conveniently.
Sampling Investigation of Power Consumption on Existing Residential Buildings in Jingzhou
Authors: Ke Chang Jun , Zhu Chun Zhao
Published: September 2013

According to various years, five residential areas about 790 existing residential buildings samples are selected to investigate the basic building information and household power status. The investigation results show that power consumption has a significant correlation with temperature and income, consumptive habits of the resident, etc. Different community residents’ power consumption in almost three years increase year by year, and there are obvious differences for different communities. Summer and winter is peak of power consumption, especially in summer. Power consumption has obvious correlation with temperature. And this rule means the necessity of energy saving reconstruction for residential building. With of urban residents' income increasing, their energy-saving consciousness falls. Energy saving consciousness should be wide publicized.
Research of Target-Controllable Optimal Dispatch for AGC Regulation Capacity
Authors: Qian Hong , Yao Yi Ming , Fei Min Rui , Deng Liang
Published: September 2013

In order to implement the target-controllability and the optimal dispatch of automatic generation control (AGC), a new dispatch method of AGC regulation capacity based on the multi-target optimal technology and the genetic algorithm (GA) is proposed. In the algorithm, the control factors are introduced by applying multi-target mathematical model. So it can control every object importance artificially according to the region of the area control error (ACE) by operators. The genetic algorithm is used to get the optimal results. Finally an example is given to demonstrate the validity of the proposed method.
Thermodynamic Analysis a Novel Wave Rotor Refrigeration Cycle
Authors: Zhao Jia Quan , Hu Da Peng , Liu Pei Qi , Liu Feng Xia , Gao Jin Ji
Published: September 2013

As a novel generation of thermal separators, the Wave rotor refrigerator (WRR) has replaced the traditional pressure-wave thermal separator. However, the isentropic refrigeration efficiency still needs to be improved compared with expander. A novel WRR system cycle was built and the system performance was thermal analyzed under various parameters, such as expansion efficiency or compression efficiency of wave rotor. The results are used to compare with the traditional WRR system. It is shown that the advantage provided by this novel cycle over the traditional WRR is an expansion process and a compression process is integrated into one unit, with a higher energy transfer efficiency and simple structure. The isentropic refrigeration efficiency of this novel cycle can be more than twice of the traditional WRR under the pressure ratio of 1.1. The experimental works are carrying out.
Operation Optimization of CCHP System by Linear Programming with Graphic Solution in China
Authors: Tang Ji Xu , Qin Chao Kui , Liu Jun Peng
Published: September 2013

Solving efficiency of CCHP (Combined-Cooling, Heating and Power) system operation optimization by Linear programming (LP) is very important. The graphic solution is introduced to improve the solving efficiency, and the result of numeric study shows that the calculation efficiency is increased by 53.2 times faster than conventional loop method. Comparison study on several schemes for hotel, office building and shopping mall with different PGU capacity (PGUcap) was taken, with the increasing of PGUcap, annual energy charge (AEC) decreases and pay back period (PBP) gets longer. Hotel has the shortest pay-back period (PBP) in the three buildings. Finally, the influence of gas price on system economic in the three buildings was analyzed.
Effects of Multi-Walled Carbon Nanotubes on Enhancing the Thermodynamics Characteristic of Alkali Nitrate and Chlorate Salt for Concentration Solar Plants
Authors: Wu Di , Liu Shi
Published: September 2013

Solar thermal power generation technology is the most feasible technology to compete with fossil fuels in the economy, and is considered to be one of the most promising candidates for providing a major share of the clean and renewable energy needed in the future. The appropriate heat transfer fluid and storage medium is a key technological issue for the future success of solar thermal technologies. Molten salt is one of the best heat transfer and thermal storage fluid for both parabolic trough and tower solar thermal power system. It is very important that molten salt heat transfer mechanisms are understood and can be predicted with accuracy. But studies on molten salts heat transfer are rare. This study will lay a foundation for the application of carbon nanotubes in molten salt which can remarkably improve the stability and capacity of thermal storage. Thermal analysis methods and scanning electron microscope (SEM) are utilized to provide a review of thermophysical properties and thermochemical characteristics of the MWCNTs-salt composite materials.
Energy Reduction of Refined Sugar Drying Process in Rotary Dryer and Conditioning Silo Consolidate
Authors: Phoosodsoong Chamlong , Sookkumnerd Chanoknun
Published: September 2013

Amount of water content in fresh air phenomena direct heat affect to be changed fresh air to hot air state for reducing refined sugar moisture during drying and conditioning process. A change relative humidity of air results in a significant variation of heat transfer rate. Therefore, in this research energy reduction of refined sugar drying and conditioning process study of these phenomena was conducted both experimentally and theoretically. Several experiments was performed employing a rotary dryer and a conditioning silo. In each experiment one of the air moisture content was changed and the resulting consumption of steam changed on the process was measured. The objective of this research was to reduce exhaust steam to heated up fresh air to hot air by installing dehumidifier. Evaluation of these results showed that the low humidity of fresh air are well suited for applied of refined sugar drying process, giving the perfect performance in which quality of refined sugar impacted can be eliminated and reduction of energy can thereby improve, with the aim of enhancing energy saving.
BOCS Based Power System Stability Margin Estimation
Authors: Ding Li Jie , Fan Hang
Published: September 2013

This paper focuses on the estimation of the stability index of a power system after a severe disturbance. The description of the stability margin has always been a challenging issue but by introducing a ball-on-concave-surface system, the assessment of the power system stability is equivalent to the analysis to the motion state of the ball on concave. According to the continuous measurement of PMU, the parameter of the concave can be determined which is useful to judge the stability margin of the power system. Tests have been conducted on the systems with two generators and results show it can be accurate and reliable.
Research on Optimization Technology of Electromagnetic Transformer
Authors: Zhao Jing Ying , Yao Fang , Mi Yan Zhi , Qin Na
Published: September 2013

Taking the typical electromagnetic voltage transformer JDCF-110 as the research object, according to the performance characteristics, the optimization mathematical model is set up. Ant colony algorithm is selected as optimization algorithm. With the cost as objective function, the settings of key parameters are studied on in optimization design. By use of Visual C++ language, the optimization design software of electromagnetic voltage transformer is finished on the plat of Windows XP. According to users requirement, the basic design and the optimized design of electromagnetic voltage transformer can be conveniently and quickly realized.
Study on the Methodology of Detection for Power Cable Insulation Defects Based on Oscillatory Wave
Authors: Quan Yu Sheng , Wang Dai Juan , Chen Guang , Zhang Zong Cheng
Published: September 2013

Water tree, electrical tree and electrochemical tree formed by premature defects of the cable can induce fault. The failure rate of the cable connecter which is higher than cable itself can emerge water tree, electrical tree and electrochemical tree. Meanwhile, the flashover, partial discharge and overheated of the cable joint are also the important reasons for fault. The oscillatory wave of detecting the power cable insulation defects based on is put forward in this paper in terms of the problems existed in the cable detection technology. With the application of oscillatory wave and signal source on the spot, this method dynamically generates reference database of detecting the cable insulation defects, to discriminate the fault patterns correspond to the maximum of function and detect the type, location and severity of cable insulation's defects. Water tree fault of premature cable itself and cable joint can also be detected in this method.
Design and Application of High Potential Acquisition System for Corona Current Measurement
Authors: Xiang Yu , Lu Tie Bing , Liu Yang , Wang Xiao Bo
Published: September 2013

Radio interference is an important issue that must be considered in designing HV transmission lines. It is caused by corona current which is due to the complex movement of charged particles around the conductors. Corona current has the characteristics of wide spectrum and strenuous diversification, so it is difficult to measure. In this paper, a corona current measurement system is developed for the investigation of HV test line. The measurement principle and system configuration is described. Problems such as high-voltage insulation, high-frequency signal sampling, interference suppression, signal record and transmission etc. are considered. The system has high measuring accuracy and the characteristic of small size, light weight and easy operating. The signal would not be interrupted and transferring data and the safety of person is ensured. The feasibility of the developed measurement system is validated by the experiments carried out in laboratory.
Research about Subsynchronous Oscillation Caused by High-Voltage-Direct-Current
Authors: Zhou Nan , Wang Guan Rong
Published: September 2013

Torsional interaction exists between HVDC converters and turbine-generators, and negative electrical damping provided by HVDC may cause subsynchronous oscillation (SSO) that can lead to turbine-generator shaft failure and electrical instability at oscillation frequencies lower than the fundamental system frequency. This paper makes a preliminary inquiry about the subsynchronous oscillation mechanism caused by the HVDC system, and puts forward Subsynchronous Damping Controller, and eventually makes a damping synchronous oscillation of the electrical Damping torque increment out of the generator electromagnetic torque to suppressing SSO.
Design on Synchronize Debugging Device for Extra High Voltage Transmission Line Longitudinal Protection
Authors: Li Rui , Song Shu Yong , Zheng Hui Ping , Ma Zhen Guo , Li Hui Yong , Zhang Tong Yu
Published: September 2013

Because of time urgent before putting into operation and different place line protection equipment located, joint debugging for extra high voltage (EHV) transmission line is often not perfect although EHV transmission line is very important for modern grid. In joint debugging process, we tend to adopt static method to do fault simulation, that apply analogue to the device. To overcome the shortages of static fault simulation commonly used, which cannot accurately simulate fault characteristics in runtime, a synchronous joint debugging device is designed based on based on the analysis of the joint debugging process for line longitudinal protection. The device is a lightweight and low cost embedded system with the functions of communication and phase shift, and can offer analog signals to protection devices on both ends of the line. Based on the functions and characteristics of the synchronous joint debugging device, the joint debugging process with this device of optical fiber differential protection is analyzed. The functions of this synchronize testing device can meet the requirements, turning static to dynamic joint debugging.
Position Sensorless DTC of BLDC Motor Driver Based on Sliding Mode Observer
Authors: Wang Song Lin , Xie Shun Yi
Published: September 2013

Direct torque control (DTC) which replaces the conventional current loop with torque loop can directly control the electromagnetic torque in order to reduce the torque error within the hysteresis bandwidth, and it can attenuated commutation torque ripple and the torque ripple of brushless DC (BLDC) motor with un-ideal back electromotive force (EMF) waveforms. Further, the key issue of feedback torque calculation in torque loop is the estimation of back-EMF in sensorless DTC of BLDC motor. So a sliding mode observer (SMO) is employed to estimate the back-EMF in real time. The torque and rotor speed can be derived from the estimated back-EMF. Simulation results demonstrate the proposed method is valid and effective.
An Information Security Assessments Framework for Power Control Systems
Authors: Wang Yu Fei , Zhang Tao , Ma Yuan Yuan , Zhang Bo
Published: September 2013

Information and cyber security of Industrial Control Systems (ICS) faces severe challenges and has gained considerable importance. Information security assessment is an essential component of information security assurance infrastructure mechanisms. First, a hierarchical model of smart grid was abstracted. Based on the proposed model and the information security risks and information security protection demands of power control systems, an information security assessments framework for power control systems was proposed in dimensions of system layers and life cycle to guide the security assessment contents of power control systems. Finally, a test bed function design for power control system security assessment was proposed. The power control system security test bed may include four parts, such as power control system security assessment management platform, power control system simulation environment, security assessment tools, and security policy. The proposed security assessment framework and test bed functional design can be used to guide the electric power utilities in their power control system information security efforts.
Simulation of Outdoor Near-Surface Airflows Based on a Wind Tunnel with Multiple Actively-Controlled Fans
Authors: Wang Qian , Meng Qing Hao , Man Yan Peng , Wang Jia Ying , Zeng Ming , Li Wei
Published: September 2013

In this paper, multiple actively-controlled fans generate outdoor near-surface airflow in a wind tunnel with once-through openings. The wind tunnel system consists of 6 groups of fans installed on rotatable plates in a rectangular inlet. We use a stochastic strategy to control the fans and the rotatable plates to regulate wind speed and direction that fluctuate according to the pattern of outdoor near-surface airflow. We utilize the statistics and multi-scale methods to analyze the effectiveness of the strategy for simulating the outdoor near-surface airflow. We provide comparison studies on the multi-scale entropy of wind speed, wind stability, and the standard deviation of directions between out-door wind and the tunnel generated wind. Results show that a flow field akin to the near-surface airflow in outdoor environments can be produced by the wind tunnel using the stochastic control strategy, which can be considered as a reliable experiment environment for gas pollution source localization research in outdoor near-surface breeze conditions.
Isolation and Characterization of Paraquat-Degrading Extracellular Humus-Reducing Bacteria from Vegetable Field
Authors: Wu Chun Yuan , Liu Jin Kun , Chen Shan Shan , Deng Xiao , Li Qin Fen
Published: September 2013

The aim of this paper is to isolate pure cultures that are capable of degrading paraquat (PQ) anaerobically with humic substances (humus) as the sole electron acceptor. Three facultative anaerobic bacteria (PQ-1, PQ-2, and PQ-3) were successively isolated from vegetable soil in Sanya city, China, via enrichment procedure with PQ and anthraquinone-2,6-disulphonate (AQDS) under anaerobic conditions. Batch experiments were conducted to investigate isolates PQ anaerobic degradation activity. Results showed that three strains were all capable of degrading PQ directly with AQDS as the sole electron acceptor (18.6% removal within 48h), and the microbial process might be AQDS dependent. The addition of low molecular weight organic substrate, such as sucrose, could enhance the anaerobic degradation of PQ from 18.6% to 34.2%, and the degradation rate reached 100% after 5-day incubation. This study was the first paper reporting that pure cultures have the ability to anaerobically degrade PQ with AQDS as the sole electron acceptor.
Degradation and Persistence of Carbofuran in Peanut and Soil in Field Trails as Determined by GC-MS
Authors: Chen Li , Jia Chun Hong
Published: September 2013

This paper investigated the analytical method of degradation and persistence of carbofuran, its metabolite 3-hydroxy carbofuran in peanut seeds, fronds and soils in field trial using gas chromatography mass spectrometry (GC-MS). Carbofuran 3GR formulation (3g a.i./100g) was applied at dosages of 2250 and 3375g ha-1in furrow at sowing peanut seeds in the fields of Langfang, Hebei province and Jinan, Shandong province, China, respectively. The soil and the plant samples were collected at different intervals and the residues of carbofuran and 3-hydroxy carbofuran were analyzed by GC-MS. The degradation kinetic result showed that the degradation of carbofuran in peanut fronds in Jinan and Langfang can be well predicted with equation: C=1.2839e-0.1733tand C=0.5731e-0.1567t, with a half-life about 4.0 and 4.4 days respectively. For the degradation of carbofuran in soils, the result coincides well with equations: C= 4.2057e-0.2229t, and C= 5.4014e-0.1499t, with half-life of 3.1 and 4.6 days for Jinan and Langfang, respectively. The pH, organic matter and clay content as well as the climatic temperature play an important role in the degradation of carbofuran in soils. 3-hydroxy carbofuran dissipated rapidly both in peanut fronds and soils, it was not detectable 7 days after treatment for all treatment, the concentration of carbofuran and 3-hydroxy carbofuran in peanut seeds at harvest time were lower than either the maximum residue limit in China or the EUs maximum residue limit of 0.1 mg kg1. Based on the data from this investigation, the use of carbofuran in peanut could be considered to be safe.
Research on the Construction of Low-Carbon Town on Basis of Recycling Economic Concept
Authors: Qin Yong Hui , Gong De Wu
Published: September 2013

The development of regional economic concept could reduce the use of resources and the destruction of environment which would increase the efficiency of resources use, environmental protection and improvement on the basis of the natural ecological routines. Recycling economic concept which is used to service for regional economic constriction is an operational method which can realize the regional sustainable development.The author first analyzed the characteristics, definition, content and principle of recycling economic concept, and then mainly study on the construction of low-carbon town from Five-Elementsand Five-Measuresaspects based on the recycling economic concept.
Investigation on the Effect of Restaurant Wastewater Pretreatment
Authors: Feng Yan , Luo Xiong Bing , He Jie , Wu Xue
Published: September 2013

By testing water quality analysis of part of the import and export of wastewater pretreatment facility catering units in Kunming shows that these pre-processing facilities catering units emit water SS, COD, BOD5, Anionic Surfactants and Animal and Vegetable Oils compliance rate is not high, exceeded the phenomenon is more serious .It shows most pretreatment facilities catering units Kunming currently flawed，and these indicators can not be treated all the standards. Some pretreatment facilities of catering units should based on the test results improving and strengthen management.
The Ecological Design of Drainage System of Yangshuo Town
Authors: Cao Chang Chun , Tan Liang Liang , Liu You Liang , Cheng Jie
Published: September 2013

The focus of the yangshuo town drainage system is the mixture of sewage and rainwater, land of construction wedging in the original pool, storm water canal silting. By adopting the ecological design of drainage, domestic wastewater is transported to the sewage purification plant, then discharged by allowance. Carrying rainwater to the pool by ditches and pool water to the conduit of the town, Melting the drainage of rainwater and accumulation of pool water resource and enjoying landscape ecological function, actualizing being ecological cycle, it is a practicable designing.
Treatment of Pulping Wastewater by Aerobic Granular Sludge Reinforceed with Mixed-Culture Community
Authors: Chen Hong Lei , Yang Gui Hua , Chen Jia Chuan , Wu Qin , Liu Yu
Published: September 2013

Pulping wastewater was further degraded with original aerobic sludge and reinforced aerobic sludge, respectively. The results showed that the UV-vis spectral signal of wastewater treated by reinforced sludge was more weaker than that of treated by original sludge, which indicated biodegrability of aerobic sludge was optimized after reinforcement. For original sludge, COD of wastewater was decreased from 629 mg/L to 203 mg/L, and chroma decreased from 118 C.U. to 91 C.U. COD of wastewater which treated by reinforced sludge was reduced to 146 mg/L, and chroma dropped to 72 C.U. Meanwhile, the reaction kinetics of aerobic microbial process was studied, and the growth rate equations of two kinds of sludge were established. Keywords: pulping wastewater; aerobic sludge; kinetics; bioaugmentation