bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrocyclone Numerical Simulation and Separation Efficiency Optimization
Authors: Sun Xian Ming , Wei Lei
Published: October 2014

For the hydrocyclone’ separation efficiency affects by many factors, this paper combined Reynolds stress model and SIMPLEC algorithm of Fluent software with orthogonal test to simulate hydrocyclone’s operating process and analysis the flow field. Different overflow pipe wall thickness values (4mm, 8mm, 12mm), volume fraction values (1%, 5%, 10%) and inlet velocities (3m/s, 4m/s, 5m/s) was considered as the separation efficiency affective factors. Results show that the overflow pipe wall thickness has greatest influence on separation efficiency. The inlet velocity is the second and the volume fraction value is the last. The optimal combination is the overflow pipe wall thickness value 8mm, the volume fraction 5% and the inlet velocity 5m/s. The overflow pipe wall thickness value increasing can decrease the turbulent kinetic energy and increase the stability of hydrocyclone flow field.
Study on the Corrosion Electrochemical Behaviors of Three Kinds of Metal in Eutrophic Fresh Water
Authors: Cao Gang , Xia Dong Sheng , Sun Lei
Published: October 2014

The environment of fresh water has been changed greatly because of eutrophication, which made the corrosion behaviors of metals in this water become more and more complex. Presently, the study on the corrosion behaviors and mechanism of metals in eutrophic fresh water was very rare; therefore, we considered the research on this field was a very meaningful work. In this paper, the corrosion behaviors of three kinds of metal in eutrophic fresh water were studied by electrochemical methods, the influence of temperature, value of pH and dissolving oxygen content on the electrochemical corrosion behavior of three kinds of metals were investigated mostly.
Falling Simulation of Free-Standing Museum Cultural Relics Supported by Soft Pad
Authors: Zhou Qian
Published: October 2014

Free-standing museum cultural relics are easy to fall off exhibition booth and get damaged under earthquakes. To find an effective method to mitigate damage of cultural relics due to fall off, influences of soft pad under relic was studied by ANSYS/LS-DYNA program. A bronze relic supported by a soft pad was selected for analysis. Based on material properties of both the relic and the pad, finite element model of the relic was built. By simulation, Von mises stress distributions, acceleration response curves as well as kinetic energy curves of the relic were obtained; effects of the soft pad to mitigate damage of the relic were discussed. Results show that collision between the falling museum cultural relic and ground can be mitigated by soft pad due to its buffer as well as energy absorption effects. It is suggested to use soft pad under relic to provide protection. Besides, by ANSYS/LS-DYNA program, falling off process of free-standing museum cultural relics can be effectively simulated.
Identifying Real Stiffness Properties of Structural Elements of Adapted Finite-Element Models of Buildings and Structures - Part 1: Problem Setting
Authors: Novikov Pavel I.
Published: October 2014

The distinctive paper is devoted to problem of identification the dynamic characteristics of mathematical models based on the measured dynamic characteristics of real constructions. It is describes a problem of discrepancy of measured and modeling eigen pairs. It is shown that the problem is systemic. The creation and verification processes of mathematical (finite element) models used in the design constructions need some work and adjustments. For a reliable analysis of the construction ways are suggested to overcome the identified gaps using adaptive procedures.
The Effect of Water Vapor on Thermal Oxide Grown on Inconel 690
Authors: Srisrual Anusara , Petit Jean Pierre , Wouters Yves , Galerie Alain
Published: October 2014

Nickel based alloys are well considered materials for uses in high temperature applications. Inconel 690 is the one of outstanding candidate with the superior properties. The aim of this report is to present the influence of water vapor on thermal oxide film. Inconel 690 was oxidized under dry and wet atmosphere at 900°C for 30 hours. The oxidized samples were characterized by SEM/EDS, Raman spectroscopy, and photoelectrochemical technique. The results illustrated that typical thermal oxides grown on alloy composed of Cr, Fe, Ni, in forms of Cr2O3, NiFe2O4, NiCr2O4, Fe2O3, Fe2–xCrxO3and/or solid solution of NiFe2O4−NiCr2O4. The presence of water vapor affected on oxide morphology, its stoichiometry, and also semiconducting behavior. Oxide film grown under water vapor atmosphere show the homogeneity. Water vapor promoted the predominated oxide of Cr2O3with n−type semiconducting. Moreover the characterization revealed the effect of surface orientation on oxidation mechanism in case of sample which oxidized in oxygen atmosphere.
Identifying Real Stiffness Properties of Structural Elements of Adapted Finite-Element Models of Buildings and Structures - Part 3: Approbation of Experimental Methodology
Authors: Novikov Pavel I. , Belostotskiy Alexander M.
Published: October 2014

The distinctive paper is devoted to approbation of new defect identification methodology based on the dynamic characteristics of real construction. Mathematically formalized procedure of the methodology is implemented at the test bench. The proposed algorithm identifies a defect. The features of results obtained from the procedure are described.
Torque and Stress Characteristics of the Skewed-Roller Slipping Clutch Considering Frictional Contact and Dynamic Equilibrium
Authors: Feng Ming , Li Yong
Published: October 2014

The Skewed–Roller Slipping Clutch (SRSC) produces resistant torque which depends on the relative rotation and sliding between askew arranged cylindrical rollers and specially curved races. In this paper, the surface contact stress and von Mises stress distributions between the dub-off profiled rollers and races are calculated, with consideration given to the frictional contact and dynamic equilibrium of the rollers. The effects of the profiled roller’s parameters on the von Mises stress are investigated and the optimal modification parameters are calculated. In addition, the limiting resistant torque characteristics of the slipping clutch with optimal profiled rollers are discussed in detail.
The Movement Precision Analysis of Planar Four-Bar Mechanism with Joint Clearance
Authors: Yang Wei Wei , Zhang Rui Jun
Published: October 2014

The method of planar four-bar mechanism movement precision analysis is proposed when the length errors and kinematical pair clearances are taken into account. The offset vector caused by the clearance of kinematical pair is analyzed and the position vector is used to describe the position of bodies. The structure for the two-hole swing deputy is studied. The magnitude and direction of rotary vice offset is seen as random variable. The calculating formula of two-hole effective lever length model is deduced. The output accuracy of four-bar mechanism with two-hole the clearance is analyzed.
Analysis on the Selection of Tooth Number for Closed Differential Planetary Gear Transmission Mechanism and Software Development
Authors: Sun Jin Feng , Zhu Hai Feng , Wang Jun , Wang Quan
Published: October 2014

With the popularization of computer, the design of planetary gear trains is headed in the automatic direction. Based on the theoretical research of closed differential planetary gear transmission mechanism, a kind of software was developed to automatically calculate the tooth number with computer technology applied to the design of gear trains. Some research and analysis were done to the transmission mode of closed differential planetary gear transmission mechanism with the help of universal design method on gear trains. Five constraint conditions were summarized, which are gear ratio condition, adjacency condition, assembly condition, concentricity condition, and other conditions, and a optimum condition. With windows 7 as the platform, MyEclipse 8.5 as a tool, translating these conditional formulae into Java language, the software of the selection of tooth number for closed differential planetary gear transmission mechanism was developed. Multi-group datum of tooth number and also a set of optimal data can be obtained after running the software, which reduces the workload of manual calculation.
Research on the Chassis of Aircraft Recovery Trailer Based on ANSYS
Authors: Xu Zhi Hua , Du Qi Chao , Hong Zhen Yu
Published: October 2014

The traditional method of finite element that fixing constraint between suspension and chassis for the damaged aircraft recovery trailer chassis usually ignored the buffer function of suspension leading to too much stress, So aiming at that problem The constraint of trailer is fixed by the method of balance frame system. Based on FE-software ANSYS the FE module of trailer chassis and balance frame system is set up and their node is coupled by the force analysis of aircraft with half of fuel in damaged. It's result that the maximum stress is less than permissible stress.The result show that the method of balance frame system is more practical by computer simulation.
Numerical Study on the Ballistic Impact on Lightweight Composite Armour
Authors: Lu Jiang Ren , Sun Xin Li , Cai Xing Hui , Dong San Qiang , Wang Guo Liang
Published: October 2014

A lightweight sandwich composite armours has been established by comparing the ballistic resistance of the potential component materials. The ballistic-resistance properties of the armours under impacting by the bullet with 12.7mm diameter are also numerically investigated by using finite element software LS-DYNA. Numerical modeling is used to obtain an estimate for the ballistic limit velocity (V50) and simulate penetration processes. The focus is placed on the energy absorption capabilities of different component layers with same density per unit area. The influence of stacking sequence and thickness ratio of ceramic/fiber layer has been analyzed in detail. Results indicate that the composite armour having optimal thickness ratio of ceramic/fiber layer in the same density and its mass is 29% lighter than of 4340 steel target.
Structure Design of Manipulator for Pot Seedling Transplanter and Simulation Analysis
Authors: Sun Jin Feng , Li Xiao Yu , Li Wen Jun , Zhu Yong Zhang , Wang Jun , Wang Quan
Published: October 2014

In order to solve the problem of seedling damaged and inefficiency of pot seedling trasplanter, the manipulator for pot seedling transplanter came into being. The three thin finger structure was selected for the manipulator, which could weaken the resistance and leakage by employing pneumatic drive. SolidWorks software was used to establish the 3D model and virtual assembly, to analyze force on the finger on the basis of the mechanical design theory. The strength of the finger part was checked in the SolidWorks SimulationXpress module, the maximum pressure of the finger was 50040656 N/m2, which was far less than the yield strength of the alloy steel finger 620422016N/m2. The results showed that the manipulator was highly practical with reasonable structure and productivity-enhancing ability.
Study on Flexible Spin-Up Maneuver with Variable Cross-Section Based on Positional FEM
Authors: Ma Lv Zhou , Yan Yu Qin , Diao Xun Lin , Liu Jian
Published: October 2014

Based on positional finite element method (FEM) and MATLAB platform, program VBEP (Variable cross-section Beam Element based on Positional FEM) is compiled. Flexible spin-up maneuver is calculated. The calculation results show that positional FEM uses fewer elements and gains higher calculation precision and efficiency when compared with traditional nonlinear FEM, and that calculated quantity using lumped mass matrix is less than using consistent mass matrix about properties of materials under the same calculation precision.
Effect of Surface Topography on Average Film Thickness between the End Faces for Mechanical Seal
Authors: Wei Long , Zhang Peng Gao , Fang Gui Fang
Published: October 2014

In order to research and master the effect of surface topography on average film thickness between the end faces for mechanical seals, average film thickness fractal model between the end faces for mechanical seal was established using fractal parameters charactering surface topography characteristics, based on contact fractal model of the end face for mechanical seal, and solving micro-void volume. Effect of surface topography fractal parameters on average film thickness between the end faces for B104a-70 mechanical seal was analyzed by theoretical calculation. The results showed that fractal dimension D and characteristic length scale G of the end face had a great influence on the average film thickness h0, and h0 decreased with the increased of D or decreased of G; h0 decreased rapidly with the increased of D or with the decreased of G when the end face was coarser, however, it decreased slowly with the increased of D or with the decreased of G when the end face was smoother. In normal working parameters and surface topography fractal parameters range, average film thickness between end faces was in the range of 0.27~1.7μm. Studying on the effect of the change of surface topography on average film thickness has an important significance on the predicting of operating characteristics of end faces during actual operating and the design of end faces for contact mechanical seal.
A Novel RBF Tuning Strategy for Global Surrogate Modeling
Authors: Duan Wen Rui , Tian Ling
Published: October 2014

In this paper, a research is performed on the tuning strategy for the shape parameter of the RBF to improve accuracy. The shape parameter is an influential factor for the accuracy but the configuration is commonly based on experience. An algorithm is designed to optimize the shape parameter. Three high-order mathematical benchmarks are used to compare the common RBF and the optimized RBF. This paper shows that the optimized RBF is more accurate for various test functions.
Analysis for the Large Precise Equipment Assembly
Authors: Jiang Wei , Han Yan Ling , Dong Wei , Zhou Qiang
Published: October 2014

In industrial and construction process, some precise equipments should be assembled on site. The assembly requirement is very high, and it is hard to assemble the accessories together. The paper is based on a real situation in construction to study the precise equipment assembly method. First, it introduces the situation on site and the parameter of the parts of equipment need to be assembled. Then show the cost for the traditional assembly method. Put forward a new method to do the work. At last, compare the advantage and disadvantage of the two methods. The new method mentioned in the paper will greatly improve the installation efficiency in the construction.
Application of Water-Lubricated Bearings in Motorized Centrifugal Air Compressor for Fuel Cell Automotives
Authors: Feng Ming , Ren Tian Ming
Published: October 2014

Proton exchange membrane (PEM) fuel cells intended for new energy automotives require a high efficiency and reliability motorized compressor to supply pressurized air. This paper presents a study and development of a motorized centrifugal air compressor using water-lubricated bearings. Comparing the performance of water-lubricated bearing with gas-lubricated bearing, we found that under the same power consumption the load capacity of water-lubricated bearings are more suitable for high speed motorized compressor system. A prototype was built and tested to verify the possibility of the developed motorized centrifugal air compressor. The results show that the system can operate at a stable rotating speed up to 80,000 rpm. The flow rate of the pressurized air is 350Kg/h and pressure ratio is 1.52 at 60,000 rpm, with a global efficiency of approximately 80%.
The Design of Children's Multi-Function Carts Based on the Man-Machine Research
Authors: Mao Mi , Liu Li Li
Published: October 2014

Based on the development status of children's carts in the market at present, we make the man-machine relations as the breakthrough point of the design to study and analyze the existing problems of children's carts. And we design a kind of carts with the functions not only can be pushed but also can be removed. It can not only realize the basic function of the carts but also can let the users achieve the purpose of parent-child interaction to increase the feeling between the parents and the children.
ANN Based Rare Earth Lifting Permanent Magnetic Chuck Design
Authors: Ding Ning , Zhang Ding Tong , Wang Zuo Zhen
Published: October 2014

A novel and saving energy rare earth lifting permanent magnetic chuck was designed based on neural network. The working principle, the neural network model of magnetic circuit design and the self-acting driving system of rare earth lifting permanent magnetic chuck were developed. Industry prototypes were manufactured, and they verified that the proposed rare earth lifting permanent magnetic chuck was feasible.
A Network Topology Corrective Switching Algorithm for Eliminating Line Overloads
Authors: Yi Xiao Yu , Guo Wei Min , Liang Zhi Rui
Published: October 2014

With the increase of electricity consumption,the line-load tends to the limit,and easy to cause line overloads in the system. To solve this problem, a new algorithm to remove the line overloads is proposed in this paper. The algorithm greatly reduces the number of power flow calculation and improves the computational efficiency by using of the method of alternative routes for the sorting. Through the use of multipath search in the algorithm, the situation of regression is been avoided. Test has been performed with the IEEE 30 bus system. Results have been verified the effectiveness and feasibility of the proposed algorithm.
Design and Development of HLA-Based Operation-Maintenance Integration Training Simulation System
Authors: Yang Xuan Huai , Huo Yu Ping , Tian Qing , Zhang Xiu E , Gao Feng
Published: October 2014

To meet the new training requirement caused by the changing of grid management mode, a training simulation system that fits to the new mode is proposed in this paper. Based on the HLA platform, an integrated simulation framework which could coordinate different simulation modules is designed. Moreover, the key technologies of information exchanging mode, simulation time advance strategy, data filtering strategy and substation OM scene simulation are described, especially focused on the realization. At last, an application is presented, it indicates that the system is more realistic and more suitable for training the operation maintenance staff.
Linear State Estimation Based on Measured Quantity Transformation and Calculation of Transmission Losses
Authors: Lin Gui Hua , Wang Tao , Wang Yu Ying
Published: October 2014

A linear static state estimation on measured quantity transformation is proposed in this paper utilizing the high precision measurements of WAMS. Using transformation of measured quantity, the current measurements of WAMS are transformed into equivalent voltage measurement, and after simplification a constant real number information matrix is obtained, so the decoupling calculation of real part and imaginary part of nodal voltage is realized. The calculation has many advantages such as fast proposed algorithm, high estimation precision and better numerical stability. Finally, the algorithm is applied to the calculation of network loss in theory, the calculation accuracy of transmission loss is improved. The calculation results of IEEE 30-bus test system validate the effectiveness of the proposed method.
Feasibility Study about Solar Energy-Air Source Heat Pump System in Cold Region Rural Residential Applications
Authors: Ma Kun Ru , Jin Lu , Yan Li Juan
Published: October 2014

This paper proposes a solar-air compound source heat pump system, for the rural residential area of Hebei and independent villas. The system can realize heating in winter and refrigerating in summer, and demand of heat water. This paper simulates and analyzes the winter heating situation of this system. The entire heating season, heat collecting efficiency of the solar collector is 0.45 in average, and solar guarantee rate is 46%. Solar-air compound source heat pump system average COP is 4.5 in the heating season, increased by 26% than the air source heat pump system run separately , and the fluctuation range is small. Throughout the heating season, the contribution of solar collectors is 59%, the contribution of air source heat pump is 41%.
Power Transformer Life Analysis Based on Risk Assessment
Authors: Sun Yi Yun , Wang Xin , Zheng Yi Hui , Li Li Xue , Xu Qing Shan
Published: October 2014

In order to grasp the state of full life cycle of the power transformer, A new method for power transformer life analysis based on risk assessment is proposed in this paper. Firstly power transformer risk assessment is conducted and fault tree is established accordingly to make the complex transformer faults system subdivide into various kinds of basic types directly; Secondly, the Fuzzy Analytical Hierarchy Process (FAHP) is designed to analyze the fault tree, so the complex system of transformer can be quantitatively described and the reliability of transformer can be obtained; Finally, transformer aging model is established to research the change rules of the transformer runnung state and determine the duration that the transformer stays in each stages of life. In addition, the application result shows the feasibility and effectiveness of the method above.
Design of Locomotive Intelligent Watt Hour Meter Based on STM32
Authors: Yu Hui Jun , Zhou Zhi Wei , Chen Cai Biao , Gu Ju Hui
Published: October 2014

The paper focuses on the locomotive intelligent watt hour meter based on STM32. By designing Intelligent watt hour meter main function, hardware architecture, and software processes to achieve energy data display, storage, and duplex communication. The hardware structure consists of main control module, electric energy metering module, communication module and other components, electric energy metering module is responsible for data acquisition, the main control module is responsible for data processing, communications module is responsible for two-way communication. Using MATLAB software to simulate the newly developed Intelligent watt hour meter,the simulation results show that, the intelligent watt hour meter has the advantages of high precision, low power consumption, fast performance, strong anti-interference ability, low manufacturing cost etc.
Designed Controller of Permanent Magnet Brushless DC Motor Based on DSP
Authors: Zhan Gui Yin
Published: October 2014

A design scheme of the control system was put forward to solve the performance control problems of the motor in this paper, combining with the composition and working principle of permanent magnet brushless DC motor. Hardware circuit of the control system was designed with digital signal processor (DSP) as the core, which mainly consists of the power drive circuit, the motor position, speed detection circuit and winding current detection circuit. Software flow of the control system was also designed, and software program debugging was achieved on CCS3.3 DSP integrated development environment, and the rationality of the software program was validated.
Efficiency Optimization in Speed-Sensorless Control of Induction Motors
Authors: Yu Hai Fang , Gao Peng , Han Shun Jie
Published: October 2014

An efficiency optimization model for induction motors with speed-sensorless control is presented in this paper. An mathematical loss model with stator iron loss in DTC(Direct Torque Control) system is used to calculate the motors loss, the loss efficiency and the optimal flux. Additionally, the efficiency optimization control strategy combined with the speed-sensorless model is used to rebuild the simulation modeling. The simulation results with the proposed control strategy show superior effects compared to the traditional control methods. The optimal control strategy can be achieved to improve the motor efficiency.
Simulation of Permanent Magnet Synchronous Motor Field Oriented Vector Control System
Authors: Chen Wen Zhuo , Zhang Xiao Yu , Sui Xiao Mei
Published: October 2014

This template illustrates the control system of permanent magnet synchronous motor(PMSM) which uses field oriented vector control(field oriented vector control). PMSM is a complex, strong coupling and nonlinear system. And field oriented vector control could provide good performance as well as the PI controller setted with well parameter matching. Whereas limited by the number of voltage vector, the other control method of PMSM, direct torque control, could not satisfy accurate control when the machine running with a low speed. So modulation of the whole system is built here to realize closed-loop field oriented vector control control by keeping id=0 , and the machine model and the transformation among different coordinate system are discussed. The system is verified effective and feasible.
Three Phase Induction Motor Inverter Defects Diagnosis Using Voltage Spectrum of an Auxiliary Winding
Authors: El Menzhi Lamiaâ , Saad Abdallah
Published: October 2014

In this paper, a new technique for diagnosing faults in three phase voltage inverter feeding induction motor is presented. It is based on the so-called the voltage spectrum of an auxiliary winding. For this purpose, expression of the inserted winding voltage is presented. After that, discrete Fourier transform analyzer is required for converting the voltage signal from the time domain to the frequency domain. Simulation results curried out for non defected and defected inverter show the effectiveness of the proposed method.
Research on Speed Sensorless Vector Control of Induction Motor
Authors: Xu Ao Ran , Zhang Liu , Gao Yang , Gu Cai Lian , Meng Chui Yi
Published: October 2014

With the 2407 and VC33 double DSP system as the foundation of hardware, the basic idea is using a modified voltage model, implementation, and equivalent amplitude and phase characteristic of integral operation. Motor steady-state operation, the rotor counter electromotive force signal is a sine wave. And an ideal sinusoidal signal frequency for omega after integral link operation, output phase lag, amplitude to times. Observations can be found from the experiment of flux linkage and rotor counter electromotive force signal on the output phase and phase is obtained by pure integral part still have a little deviation, it will need a further study on the compensation link, how to make the compensation phase completely equivalent to the integral effect. From the point of the results of the experiment of 5 Hz low speed estimation error, verify the theory in this paper. One step closer to the test is more slow speed estimation.
Analysis Method of Power Flow in Urban Power Grid with Distribution Generation Based on Dynamic Probability Model
Authors: Yao Ming Yi , Chen Xing Ying , Liu Jian , Yu Kun , Shi Hao Jie , Wang Ji Xiang
Published: October 2014

The change of wind power generation, photovoltaic power generation and power load reflects the regularity and randomness at the same time, which leads to a casual fluctuation of power flow in urban power grid with multiple generators. The static and dynamic probabilistic power flow model are compared and analyzed in this paper, the dynamic probabilistic model is adopted for simulating the characteristics of power flow in urban power grid with multiple DGs. The results show that the power flow of urban power grid changes not only regularly but also randomly. These two characteristics of power flow should be considered for power grid dispatching and control.
Designing and Realization of a Water Quality Detecting Instrument Based on Solar Power
Authors: Wang Yi Wang , Zhang Bo , Feng Fei , Shuai Zhang
Published: October 2014

Aiming at the water quality monitoring needs,a novel solar-powered digital water quality detecting instrument was designed in this paper. The water water quality detecting instrument using digital control and solar power technologies, which has the advantages of energy saving and environmental protection.The system components,hardware and sof tware of detecting instrument is introduced,and a prototype of designed water quality detecting instrument was developed and experimental test. Compared to the existing water quality detecting instruments,the designed has the advantage of energy saving and environmental protection, portable and efficient, accurate and reliable,which can be used for industrial and civil water quality monitoring.
Case Study: Environmental, Techno-Economic Feasibility Analysis of Grid-Connected Photovoltaic Power Plants in China Using RETScreen
Authors: Chen Dong Po , Zhao Lei , Li Hai Ling , Zhou Chun Lan , Wang Wen Jing
Published: October 2014

Photovoltaic (PV) industry in China shows more growth potential because of the favorable political support, deep market penetration will be expected to follow. A detailed and comprehensive assessment for photovoltaic (PV) power plant is extremely necessary. This paper study the feasibility and profitability of the grid connect PV power plant by analyzing a case using RETScreen photovoltaic project model. It was concluded from this study that finding the optimal tilt angle is extremely necessary for the fixed installation. All kinds of financial indicators show that the project has good profitability, whether considering greenhouse gasses reduction credits or not. In addition, the results from sensitivity and risk analysis showed that avoided cost of energy、renewable energy production and initial cost have great effects on net present value (NPV). The effects of annual cost, debt rate and debt term on NPV are so small that we can ignore their impact. This study is of high value when attempting to analyze PV power plants comprehensively.
Two-Layer Optimize Algorithm for Microgrid Economic Dispatch
Authors: Ding Yan , Jia Rong , Dong Kai Song , Li Zhen , Shen Wei Cheng , Zhao Yao
Published: October 2014

To deal with the super short-time energy management of microgrid, a mixed-integer programming optimization algorithm combined with genetic algorithm is proposed. Firstly, this paper introduced the short-time economic dispatch mathematical model of microgrid. Secondly, a two-layer optimize algorithm is been developed. The lower layer takes no account of power flow constrains, convert the model into a mixed-integer programming problem through linearization techniques. The lower layer gets the generation schedule, and then passes the data to the upper layer. The upper layer takes the power flow constrains into account, optimize the unit output based on genetic algorithm. The simulation result shows that the proposed algorithm achieves a better complementary of the two kinds of optimization algorithm. At the same time, the optimization result also shows the effectiveness of the algorithm.
Research on Intelligent Control Technology of PV Grid-Connected Inverter
Authors: Zhang Yun Bo
Published: October 2014

Based on the mathematical model of the three-phase two-stage PV grid inverter, the fuzzy-PID control strategy is applied in the grid connected control of PV system in this paper. The purpose of the intelligent control of photovoltaic grid connected inverter has been achieved. The digital simulation and physical simulation show that the fuzzy-PID control strategy can improve the PV system grid control dynamic process and get the smooth connection of the PV system with the power grid. At the same time, the harmonic pollution on the grid has been significantly reduced.
Discussion about the Critical Business Demand of Smart Distribution Grid and Utilization
Authors: Yang Yong Biao , Xu Shi Ming , Huang Li , Chen Xing Ying , Yu Kun , Liao Ying Chen , Wu Li Jie
Published: October 2014

The wind-solar-storage and other distributed generation (DG) accessing to the distribution grid and user’s interaction with the grid change the business’s forms of the traditional distribute and utilize system, and while the supplier and demander of electric power also set higher requirements on business’s functions of the smart distribution and utilization system. Based on business requirement of smart distribution and utilization, the major content and function of distribution and utilization link are discussed, including intelligent planning, intelligent dispatching, self-healing control, demand side management, two-way interaction and so on. It makes the architectures of business and the objectives of construction more clear and promotes the construction of the business system in the smart distribution and utilization system.
Close-Operation Overvoltage of No-Load Transmission Line with Fault Current Limiter
Authors: Liu Hong Shun , Lv Ting Ting , Han Ming Ming , Zou Liang , Zhang Li , Li Qing Quan
Published: October 2014

The comprehensive impacts of series resonance type fault current limiter (FCL) on power system need further investigation and verification. With regard to switching on 500kV EHV no-load transmission line, the instantaneous peak value, the free component oscillation frequency, the fundamental component amplitude and free component amplitude of terminal overvoltage waveform are simulated with and without installation of FCL considering different switching times. The relationship curves of free component oscillation period, the fundamental component amplitude and free component amplitude are gotten respectively by simulation results. The law of the influence of different fault current limiting reactance on terminal voltage of switching on no-load line is also summarized. The analysis results show that the installation of FCL is benefit for switching on no-load line.
Intellectualization and Reliability Evaluation of Distribution Network Based on Principal Component Analysis
Authors: Feng Yu Qing , Yang Jian Hua , Huang Lei , Ji Bin , Su Jian
Published: October 2014

Principal component analysis is performed on the operation and management evaluation of smart distribution network because of its objectivity, synthesis and simplification to original data information. According to the demand on the evaluation that focuses on intellectualization and reliability of distribution network, an index system for intelligent and reliable evaluation is built. The performance indicators and the principal component analysis are used to analyze the intelligent and reliable level of distribution network operation and management. The feasibility of the evaluation index system is verified by the evaluation results of some distribution networks.
Medium and Long-Term Load Forecasting Using Grey Theory Based on Rough Sets
Authors: Zhang Hong , Lei Zhi Guo , Cheng Yue , Wang Yu Ming
Published: October 2014

Power load forecasting is one of the important parts in power system planning. This paper focused on the research of load forecasting and proposed an improved Rough set for mid-long term load forecasting. Based on the theory, the most sensitive factor can be found, which is applied to studying the uncertain problems of mid-long term load forecasting in this paper and one method fitting for mid-long term load forecasting are proposed. The validity and effectiveness of the method is tested in a real power system example.
Research on Optimization Model of Overseas Investment for Power Grid Enterprise
Authors: Liu Tuo , Zhang Yi
Published: October 2014

Basing on the Monte Carlo, this paper established a strategy planning model for international business strategic of power grid enterprise, by which estimating the possibility and sensitivity of a power grid enterprise.
Study on Application of Multi-Kernel Relevance Vector Machine in Data Validation of Thermal System in Power Plant
Authors: Zhao Yue , Si Feng Qi , Xu Zhi Gao
Published: October 2014

A new method for data validation of thermal process in power plant was proposed based on multi-kernel relevance vector machine (MKRVM). Hybrid kernel function combining Gaussian kernel and polynomial kernel function was applied to relevance vector machine (RVM). After optimizing kernel parameters with firefly algorithm, nonlinear data regression model was built for thermal system. Then we used measuring test method to detect data and reconstruct data with model prediction. This method can overcome multiple correlation and nonlinearity among variables of thermal system. It has good robustness against various types of noise and higher accuracy for prediction compared with SVM and RVM. The results of case analysis for thermal system in a 600 MW unit show this method can detect and reconstruct data effectively.
Numerical Analysis of Distribution of Ion Concentration Affected by Flame Temperature behind a V-Gutter Flameholder
Authors: Luo Xue Jiao , Fan Wei Jun
Published: October 2014

To obtain evident ion current signals which reflect combustion condition in afterburner, areas of high ion concentration need to be identified. Using C12H23as the fuel species, H3O+, CHO+, COH+, O-and OH-as main ions, total ion concentration and temperature in flame behind a V-gutter flameholder are numerically simulated by realizable κ-ε turbulent model and non-premixed equilibrium chemistry model. Outlet section temperature is in good agreement with experimental data. The results show that distributions of ion concentration and temperature are consistent. There are two areas of high ion concentration: regions of the highest temperature in recirculation zone; regions close to upper and lower edges of flameholder. Peaks of each area appear near the injection holes.
Comparison of Capacity for 2,3-Butanediol Production from Corn Cob Hemicelluose Hydrolysate Fermentation by Klebsiella oxytoca HD79 and Klebsiella pneumoniae
Authors: Ge Jing Ping , Huang Shou Feng , Li Xing Lin , Pan Chao , Ping Wen Xiang
Published: October 2014

Production of 2,3-Butanediol (2,3-BD) from renewable resources can be sustainable and inexpensive. Many studies have been done on the fermentation usingKlebsiellapneumoniae,KlebsiellaoxytocaandPaenibacilluspolymyxa. Although significant quantities of 2,3-BD have been accumulated by these bacteria, which one is the best strain of great fermentation capacity still be insensible. In this paper,KlebsiellapneumoniaandKlebsiellaoxytocaHD79 were opt to ferment concentrated and non-detoxified corn cob hemicelluose hydrolysate and concentrated detoxified hydrolysate. Then glucose was utilized as carbon source to verify the quality of the hydrolysate. At last, we compared the fermentation capacity between them. The results showed thatK.pneumoniaehas more resistance with inhibitors thanK.oxytocaHD79,which has showed better ability of producing 2,3-BD.K.pneumoniaemight be a promising strain for 2,3-BD production using renewable resources.
Research on Double-Stream Coil-Wound Heat Exchanger
Authors: Xue Jia Xing , Zhang Zhou Wei , Wang Ya Hong
Published: October 2014

A calculation method for double-stream counter-current coil-wound heat exchanger is presented for methanol-methanol heat exchange process. The numerical simulation method is applied to determine the basic physical parameters of double-stream spiral pipes. A recycling methanol cooler is designed and calculated by numerical simulation and programmed iterative calculation. The calculation data is analyzed by comparing with different variables. The result shows that the introduction of numerical simulation can simplify the pipe winding process and accelerate the calculation and design of overall configuration. This method can be used for physical modeling and heat transfer calculating of spiral pipes in double-stream coil wound heat exchanger, program to calculate the complex heat transfer changing with different variables and optimize the overall design and calculation process of double-stream spiral pipe bundles.
Study on the Basic Characteristics of Low Oxygen Air Combustion with Natural Gas in Glass Tempering Furnace
Authors: Xia Jia Qun , Liu Guang Hui , Wang Yu Si , Li Hu Ping
Published: October 2014

The basic characteristics of natural gas with low oxygen air combustion is analyzed, and low oxygen content, excess air ratio, and the change of flue gas composition are studied, the results show that using the technology of low oxygen air combustion for glass tempering furnace in production has directive significance. The composition content of carbon dioxide and water vapor increases in the combustion products. The radiation heat transfer is decreased in glass tempering furnace. The furnace temperatures are maintained in the range of 650 to 800°C.
The Study of Heat Transfer between Adjacent Units on Household Heat Metering
Authors: Yang Jin Gang , Zhan Nai Yan
Published: October 2014

Introduces the concept of the heat metering and charging regulation coefficient, describes its’ calculation and the procedures of regulation, also summarizes the calculate formulas. and analyzes the effect of heat transfer between adjacent units on household heat metering, as well as the influence of different floor and different position in a building, different orientation, the area of window contrast to wall, cold wind infiltrating and the natural capacity of heat preservation of surrounding structure and so on. According to the Heating Company, Heating price is 0.14 yuan/kWh. Heat cost consists of two. One is basic cost,the other is changed cost. The proper temperature being on duty is probably 7°C when there is heat transfer between adjacent units. When nobody lives in the rooms, some cost must be paid. Also introduces the concept of the metering and charging regulation coefficient, describes its calculation and procedures of regulation.
Study of Pressure Characteristics in PWM Controlled Variable Rate Spraying System
Authors: Liu Hai Hong , Wei Xin Hua , Du Jin Feng , Huang Jia Bao
Published: October 2014

In PWM controlled variable rate spraying system, spraying quantities were regulated by fast switching solenoid valves. However, hydraulic impacts were generated by these fast switching solenoid valves in pipe system, which affected stabilities of spraying quantities and atomization characteristics. In order to study pressure changing regularities when solenoid valves operated, then to design a pressure controller to improve spraying qualities in PWM controlled variable rate spraying system, Fluent was used to simulate pressure characteristics in the pipe system and pressure curves were drawn under the following 3 working conditions, solenoid valve opening, closing, and switching continuously with 5 Hz frequency and 50% duty ratio. Related experiments were carried out to test real pressure signals in the pipe based on a PWM controlled variable rate spraying system. Relative errors between simulation results and experiment results were below 10%. Thus, this simulation model of PWM controlled variable rate spraying system in Fluent was reliable to simulate pressure characteristics in the pipe in other common working conditions, and which contributed to design pressure controller and to optimize the whole PWM controlled variable rate spraying system.
Research on Supersonic and Subsonic Field of Externally Pressurized Gas Lubricated Bearing
Authors: Chen Chang Ting , Yang Jin Fu , Wang De Jun
Published: October 2014

The flow passage including supply hole of externally pressurized gas was investigated. The outlet velocity of supply hole, bearing number and supply pressure’s relationship were built. According to supply hole’s speed, supersonic or subsonic model was chosen to calculate bearing clearance’s pressure distribution. Bearing number’s effects on pressure’s distribution was also studied. The calculation result shows that at larger bearing number, supply hole’s speed is harder to be chocked. Both in supersonic and subsonic condition, larger bearing number produces lower pressure loss.
Experimental Study on Throttling Refrigeration System Using Mixed Refrigerants
Authors: Meng Zhao Feng , Wang Fang , Qu Yan , Zhao Ya Le , Li Tang
Published: October 2014

This experiment applied to the Linder refrigeration with subcooler and used the new pentabasic refrigerants (N2/CH4/C2H4/C3H8/iC4H10).It can basically achieve the cryogenic temperature of 170k and has the advantages of simple structure and low manufacturing cost. The mixed refrigerants of four hydrocarbons and nitrogen used in the system have the low ODP and GWP and reduce the flammability of the components which improve the safety and stability of the system. Research using the method of thermodynamic analysis of exergy efficiency determine the initial ratio of the mixed refrigerants. A way of optimal ratio of mixed refrigerants is proposed.The experiment results show that the best ratio of pentabasic refrigerants (N2/CH4/C2H4/C3H8/iC4H10) is 32:20:12:20:16,the cryogenic temperature is around 170k and the cool-down time is 75 minutes.
The Load’s Control of Central Air Conditioning System Based on Comfort
Authors: Fei Jun Tao , Chen Xing Ying , Xu Shi Ming , Chen Lu , Liao Ying Chen , Wang Gang , Peng Kun
Published: October 2014

Nowadays, the power load has been well increased and the differences between the crest and the valley of the load has become larger and larger. At the same time, the central air conditioning system plays a more important role in modern life and it has the potential to change these differences. In this paper, in view of a building’s central air conditioning system, central air conditioning system’s power load unload model have been built. A method of calculation of the ability of central air conditioning to unload the load which is based on comfort has been proposed. And it uses the enumeration method for solving optimization of the unloading. Via this research, we can figure out how much load can be unloaded to ease the crest and the valley of the load. And how can we minimize the loss of comfort can also be published.
Study on the Saccharification Conditions of Fuel Ethanol from Corn Straw
Authors: Zhang Min , Li Jin Yang , Fu Hai Bin
Published: October 2014

To study the saccharification conditions of cellulase on lignocellulose material, this paper used corn straw as the material to do research on the effect of cellulase. The hydrolysis factors, including reaction temperature, reaction time and cellulase concentration, were measured in order to determine the optimal saccharification conditions for fuel ethanol production. The results showed that, when the reaction temperature was 45°C, reaction time was 72 h and cellulase concentration was 60 IU/g, the hydrolysis rate can respectively reach 6.25 %, 14.7 % and 14.4 %. By the analysis of orthogonal test, the main factors effects the saccharification was reaction time. And the optimal combination of saccharification conditions was the reaction time of 54 h, the reaction temperature of 45 °C, and the cellulase concentration of 55 IU/g.
The Research of Constant Temperature and Humidity Air-Conditioning System of Underground Cellar
Authors: Wang Wei , He Ming Xing , Liu Ce Yue , Zhang Yuan
Published: October 2014

Accordance with the high Precision control problem of constant temperature and humidity air-conditioning system of wine storage of large underground cellar and based on the cellar building construction features and the reasonable allocation of ducts and valves., this paper proposes the distributed intelligent temperature and humidity PLC control solution and designs a remote monitoring system and gives the test results. Actual operating results show that the use of distributed PLC control constant temperature and humidity control system with high efficiency, low energy consumption, remote operation of the file, and meet the environmental requirements of various types of wine storage.