bluuebunny/crossref_metadata_2025 huggingface dataset:
Heat Exchanger Working Condition under Low Temperature and Simulation
Authors: Wang Zhi Yuan , Wang Liu
Published: December 2014

The frost is easy produced by the surface of evaporator, when finned tube evaporator works, especially in the low temperature and high humidity conditions. COP, electrical power, cooling capacity and frost quantity have significant differences at the conditions of different temperature and humidity. When air conditioning system is used in different areas, system parameters change greatly, so it is important that the experimental research on the heat exchanger in low temperature conditions. The temperature field of the evaporator is calculated and simulated by software, and the simulation results are analyzed and explained.
Application of Expert System PID Algorithm to Heat Exchange Station
Authors: Meng Song , Liu Yong Qi , Han Xin Jie , Ge Zhan Yuan , Wang Shi Lin
Published: December 2014

The heat exchange station is important element which connect to the heat source and the users. Heat exchange station has the characteristics of great inertia, pure lag, time-dependent nature. So it is difficult for conventional PID controller to control the system. Expert system PID controller combines the advantages of expert system and the conventional PID. It can deal with all kinds of complicated situations. The results show that this scheme completely conform to the requirements of the system control.
Performance and Operation Analysis of a Quadra Sectors Rotary Airheater Adopted by CFB Boiler
Authors: Li Zhan Guo , Zhao Zhen Ning , Wen Zhi Qiang
Published: December 2014

Based on the aspects of thermal properties, resistance properties, air Leakage Control and boiler output adaptability, the operation modes and their impact of a quad-sector rotary airheater adopted by a 330MWe circulating fluidized bed boiler are analyzed by tests. And the operation methods of Leakage Control System are concluded. In order to improve the reliability of rotary airheater with main and auxiliary motors, recommendations for improvement are extended.
Key Problem Analysis and Solution on Intake Water and Heat Transfer of Sewage-Source Heat Pump System
Authors: Bi Hai Yang , Shang Yong Mao , Gu Xiang Hong
Published: December 2014

Changing "high consumption energy, low temperature heat to the indoor, waste heat to the environment", and turning the HVAC harmoniously into the natural ecological cycle, conform to the trend of the development of ecological architecture. Heat pump technology is a way of HVAC energy saving the most practical. Although low heat and cold source of the city sewage is ideal, but the quality is very unstable, can not meet the operation requirements of heat exchange equipment. This paper analyzes the key problems of the sewage side in sewage source heat pump technology application in the present: hair dirt clog sewage heat exchanger; fouling in heat surface reduces the heat transfer performance, and results in large heat-transfer equipment in the practical application. According to the key problems of sewage side, this paper prevents hair clogged with large tube heat exchanger; reduces the fouling thermal resistance, and enhances heat transfer process using the heat exchanging technology of circulating fluidized bed.
Laminar Heat Transfer Performances in a Tube with Center-Cleared Twisted Tape of Alternate Axes
Authors: Chen Li Xiang
Published: December 2014

To improve the heat transfer performance of laminar tubular flow, a center-cleared twisted tape of alternate axes was developed as inserts. Numerical simulation was conducted to investigate the effect of dislocation angle of twisted tapes on the thermo-hydraulic performances. The numerical results show that, the largest Nusselt number occurs at a dislocation angle of 60°. The friction factorfis relatively larger than that when the dislocation angle is 0°, and it exhibits an obvious increment with the dislocation angle. From the value of performance evaluation criterion (PEC), the best thermo-hydraulic performance is achieved at a 60° dislocation angle. The underlying mechanisms are analyzed in terms of flow field and temperature field.
Organic Rankine Cycle Simulation Based on Aspen Plus
Authors: Lv Han , Jiang Wei Ting , Zhu Qun Zhi
Published: December 2014

Organic Rankine cycle is an effective way to recover low-grade heat energy. In order to improve system performance, for low-temperature waste heat of 120°C and R245fa,R600a,R227ea organic working fluid, using Aspen Plus software conducted simulation by changing the evaporation temperature. Results from these analyses show that decreasing the evaporation temperature, increasing thermal and exergy efficiencies, evaporating pressure, at the same time reduce steam consumption rate.
Research and Develop on Series of Cryogenic Liquid Nitrogen Coil-Wound Heat Exchanger
Authors: Zhang Zhou Wei , Wang Ya Hong , Xue Jia Xing
Published: December 2014

The research and development situation of liquid nitrogen coil-wound heat exchanger were discussed in view of heat exchange in gas purification field in petrol-chemical industry. The basic designing methods and the multi-stream heat exchange process were illustrated by the cryogenic and high pressure crossing heat exchange equipments of liquid nitrogen coil-wound heat exchanger with multi-stream and multiphase flow, including Three-stream back-cooling heat exchangerin first stage, Four-stream back-cooling heat exchangerin second stage, Five-stream back-cooling heat exchangerin third stage, Multi-stream main back-coolingcoil-wound heat exchanger etc. A series of coil-wound heat exchangers with different mixed fluids and different applications were described. The winding structure characteristics and the work principles of the spiral pipe bundles were elaborated to give references for the scientific design and calculation of coil-wound heat exchanger in cryogenic field. The important research directions and the critical scientific problems were forecasted.
Analysis and Research on the Influence Factors of the Spark Plug Ion Current in Spark Ignition Engine
Authors: Song Chang Qing , Li Jun , Qu Da Wei
Published: December 2014

The spark plug ion current signal carries abundant information about the engine combustion process. Real-time acquisition of the spark plug ion current signal can effectively extract the characteristic parameters, then enhance the power, fuel economy and emissions of the engine. The paper analyzed the influence factors of ion current, designed an acquisition and analysis system of spark plug ion current signal, and mainly studied the influence of spark plug gap and bias voltage on ion current signal in a six-cylinder four-stroke gas engine. The results show that the bias voltage and the spark plug gap have a great impact on the spark plug ion current signal. The ion current signal intensity is directly proportional to the bias voltage applied cross the spark plug, and inversely proportional to the spark plug gap. Results also indicates that the ion current is directly proportional to the mobility and concentration of charged particles in burned gas plasma.
Study on the Shutdown State of CNG Engine
Authors: Yang Shi Chun , Gao Yan Fei , Li Ming , Gu Yue , Liu Wei
Published: December 2014

We studied the shutdown state of natural gas engine on a modified GW4B13 direct injection engine. The result shows that when the engine is cold, high speed hold a dominant factor, causing the engine spends longer time shutting down than the time under the hot engine situation; stop position of the engine is normal distribution, and the majority of the stop position is located before the top dead center between 70° to 90°; when the stop position before the top dead center 90° and 120 ° , the engine spends shortest time, less than 0.3s, reaching the target speed, i.e. the idle speed 400rpm.
Multi-Field Coupling Modeling and Analysis for Cylinder Liner of Slow Speed Two Stroke Marine Diesel Engine
Authors: Xing Hui , Guo Lei , Wu Ji
Published: December 2014

To predict accurately the stress and deformation of combustion chamber components of large slow speed two stroke marine diesel engines, based on AVL Fire and ANSYS Workbench software, multi-field coupling modeling and analysis technology was employed to carry out the strength analysis for combustion chamber components of crosshead type marine diesel engine. The boundary conditions, i.e., the temperature field distribution, the mean temperature and the mean heat transfer coefficient are obtained firstly. Then the strength analysis for cylinder liner of crosshead type marine diesel engine under the thermal loads, mechanical loads and thermal mechanical coupled loads was conducted. The results show that the strength meets the design requirement and the stress concentration and the deformation of the cylinder liner were mainly dependent on the thermal load.
Numerical Simulation of the Unsteady Aerodynamic of Wind Turbine under Yaw Condition
Authors: Chen Xiao Ming , Kang Shun
Published: December 2014

To be able to more accurate analysis aerodynamic characteristic variation under yaw of NREL Phase VI wind turbine. The influence of yaw on the aerodynamic characteristic by using a three-dimensional unsteady CFD methods based sliding mesh in this paper. To flow, the overall performance and Cp of the three-dimensional flow numerical simulation were compared with experimental results with the same wind speeds to confirm the reliability of the model at a given axial wind speed conditions. In the yaw conditions, the effect of yaw on the aerodynamic performance of wind turbine blades, changing law and reveal the aerodynamic performance is in the flow details and rules in different azimuth.
Feedback Particle Swarm Optimization for Shipboard Power System Restoration
Authors: Chen Yang , Liu Yan Cheng , Wang Chuan
Published: December 2014

The fast network restoration is required to restore the Shipboard power system (SPS) to near pre-fault condition for proper functioning. This paper proposed an improved Particle Swarm Optimization for restoration of shipboard power system. Firstly, we proposed an improvement strategy of S-Curve Decreasing Inertia Weight. Secondly, the feedback mechanism was introduced to improve the algorithm rate of convergence. Particle swarm optimization algorithm enables to find the optimal combination of loads that can be supplied after the occurrence of the fault, considering the priorities of the loads and the constraint of balance between the total load and total generation. The proposed method is applied to a naval shipboard power system model.
Model Research on Energy-Saving Potential of Engine Energy-Saving Technology
Authors: Shao Li Qing , Zhang Hai Bo , Ding Qian , You Jia Xun
Published: December 2014

Engine energy-saving technology is the key direction of passenger car energy-saving. This paper has built energy-saving potential model, which could forecast the potential of engine energy-saving technology in 2015 and 2020 under such two constraints: overall target requirement of fuel consumption and curb weight range. Afterwards, the model was used to calculate energy-saving potential of narrow sense passenger cars (including basic car + SUV + MPV), which were equipped with single turbo charging technology, single GDI technology and the above two kinds of technologies integration. The research results will provide decision-making support for enterprises’ technology selection and product development.
Feature Extraction of Vibration of Centrifugal Fan Based on LLE
Authors: Liao Yong Hao , Liu Bo
Published: December 2014

In order to improve classification ability and diagnostic accuracy of centrifugal fan signals, a new feature extraction method from fault signals of centrifugal fan vibration based on manifold learning method (MLM) that is a kind of reduction method of data dimension is proposed in this paper.The MLM is able to remain nonlinear information of original signal, to improve the classification and diagnostic ability of fault better than traditional reducing dimension methods. The results in this paper show that, fault feature information of centrifugal fan vibration is extracted effectively by the MLM and the fault feature information of different types are separated effectively in themselves areas. The diagnostic accuracy by feature extracted by the MLM is significantly higher than by the wavelet packet analysis method.
An Appraisal of Turbulence Dissipation Rate Estimation Methods Using Large Eddy Simulation
Authors: Chen Jing , Chen Yi Liang
Published: December 2014

Various methods –direct methods, structure function methods and dimensional analysis-have been proposed to estimate the dissipate rate of turbulent kinetic energy. In this study these methods were appraised using LES data of a turbulent flow in the straight pipe at Re=5300. The fact that the corrected second-order structure function method is robust can be found. Note that when approaching to the wall at low Reynolds number, structure function methods and dimensional analysis method usually become inaccurate since they can not reflect information about the radial gradients. Direct computation methods now give acceptable trend and good estimation. Methods mentioned above lead to the same order of magnitude as values from DNS data most times.
Experimental Study on Effect of Meteorologic Parameters on Evaporative Cooling System Performance
Authors: Zhou Xiao Feng , Miao Xiao Ping , Yang Jun , Jiang Feng
Published: December 2014

Based on experimental platform of the evaporative cooling system and a large number of experimental data, the influence of air relative humidity and dry bulb temperature on the energy consumption ratio (ECR) of the evaporative condenser is studied. Resorting to the test data, linear, quadratic and cubic fitting surfaces are used to get the function of energy consumption ratio with two variables, dry bulb temperature and relative humidity. The fitting and validation results show that the quadratic surface approaches the real data best among the three manners.
Research on PTN Networking Planning Technology
Authors: Fan Ya Qin , Li Chi , Wang Jing Ya
Published: December 2014

This paper studied the technology of PTN networking structure and networking planning technology. We studied the key technology of PTN, the relevant algorithm to optimize PTN networking. Using matlab simulation software we realize kruskal algorithm to construct minimum spanning tree. The results of this study can improve the efficiency of the network, and reduce network construction, reduce the operation cost. It has good social and economic significance.
Research on the Time Synchronization Technology of Wireless Sensor Network
Authors: Fan Ya Qin , Wang Jing Ya , Liu Shu Ting
Published: December 2014

The paper studies the basic characteristics and the definition of the wireless sensor networks, the time synchronization of wireless sensor network and the algorithm of time synchronization in wireless sensor networks. This paper studies the RBS algorithm and its improved algorithm. The research results have practical significance to the rapid development of network and the future network.
Research on Inverter Side Steady Operation of Direct-Drive Permanent Magnet Synchronous Wind Power System
Authors: Cheng Ruo Fa , Chen Li Hu , Yu Xin Hong , Ma Yin Ping
Published: December 2014

Currently, back-to-back converter is widely used in rectifier and inverter of direct-drive permanent magnet synchronous wind power system. But there are two shortages in the system, not stable of control effect and higher ripple of DC voltage. The dual-channel parallel boost converter can shunt the DC current, reduce the ripple effectively, and improve the quality of inverter side DC current. The paper uses the space vector pulse width modulation control strategy to control the inverter. Simplifying and decoupling the complex control system and control the DC bus voltage to remain stable. The simulation results confirm that dual-channel parallel boost converter have a better control effect than back to back converter, it through control the inverter to make power quality reached the grid connected requirement, verified the correctness of the design of inverter.
A Heuristic Reduction Algorithm Based on the Feature Weight
Authors: Xing Xiao Xue , Du Li Min , Shang Wei Wei
Published: December 2014

The basic attribute reduction algorithm based on discernibility matrix was introduced. Through analyzing the algorithm, the shortages were found. Then the heuristic reduction algorithm based on the feature weight is presented in the paper. In the algorithm, the discernibility matrix and the heuristic knowledge are combined toghther. It can be proved that the proposed algorithm is more intuitive and easier in computation. At the mean time the speed of the reduction algorithm could be improved.
Research of Bidirectional Power Flow Algorithm of Micro-Grid Based on the Improved Zbus Method
Authors: Gu Cai Lian , Ji Jian Wei , Liu Li , Xu Ao Ran
Published: December 2014

Themicro-grid technology is an effective way to promote renewable energydevelopment and utilization. Low voltage micro-grid can absorb photovoltaic,wind power and other large number of scattered random distributed power supply,and the system may be three-phase asymmetry while operation, randomness of thepower output and load is stronger. Therefore an improved bidirectional power flow algorithm is putforward suitable for low voltage micro-grid. According to the physicalstructure components of the micro-grid and different kinds of micro powersupply, the types of micro-grid in power flow calculation is studied to dealwith complex node in the micro-grid, improved Zbus algorithm is proposed tocalculate the power flow of micro -grid .IEEE-69 is taken as an example for simulation, the resultsshow that the proposed method is better for the biggest error ratio of voltagedrop and calculation time than traditional method. Atthe same time the algorithm is also suitable for island operation state of the microgrid.
Wind Speed Change and Influence on Wind Energy in Recent 50 Years over Hexi Corridor
Authors: Zhang Yao Zong , Zhang Bo , Liu Yan Yan
Published: December 2014

Based on wind speed data of 13 meteorological stations in 1958-2012,Mann-Kendall nonparametric test methods was been used to study on wind speed changes in Hexi Corridor.Spatial and temporal characteristics of seasonal and monthly wind speed changes was examined. (1) The maximum wind speed appeared in the higher elevations of study area, such as Wushaoling and Mazongshan station. From east to west mean wind speed increased in Hexi Corridor.For nearly 50 years wind speed had showed decreasing trend. (2)In each season Spring with an maximum mean wind speed was 3.4m/s,the Summer mean wind speed was 2.9 m/s,Autumn mean wind speed was 2.6 m/s,the mean Winter wind speed was 2.8m/s.The seasonal wind speed mainly had decline trend, each station.has different characteristics trends (3) Mean wind speed in each month was greater than 2.5m/s,maximum monthly wind speed appeared in April was 3.5m/s,the minimum wind speed appeared in the September-October was 2.53m/s,the wind speed in March,April and May was greater than the November month,December,January.In addition to Mazongshan and Wushaoling,other station monthly wind speed showed a decreasing trend.Monthly mean wind speed in Jiuquan,Dingxin and Zhangye was slow decreasing trend.Anxi,Yumen wind decreasing trend were more obvious.(4)Wind decreasing trend will have a significant impact on wind energy, wind speed changes and wind energy should be evaluated in the future.
An Adaptive Chaos Quantum-Behaved Particle Swarm Optimization Algorithm for Real-Time Dispatch in Power System with Wind Generation
Authors: Wu Zhi Kui , Deng Chang Hong , Xiao Yong , Zhao Wei Xing , Xu Qiu Shi
Published: December 2014

A real-time dispatch (RTD) model for wind power incorporated power system aimed at maximizing wind power utilization and minimizing fuel cost is proposed in this paper. To cope with the prematurity and local convergence of conventional particle swarm optimization (PSO) algorithm, a novel adaptive chaos quantum-behaved particle swarm optimization (ACQPSO) algorithm is put forward. The adaptive inertia weight and chaotic perturbation mechanism are employed to improve the particle’s search efficiency. Numerical simulation on a 10 unit system with a wind farm demonstrates that the proposed model can maximize wind power utilization while ensuring the safe and economic operation of the power system. The proposed ACQPSO algorithm is of good convergence quality and the computation speed can meet the requirement of RTD.
Study on the Heat Transfer Mechanism of Ceramic Solar Collector
Authors: Zhou Guang , Lin Yong Man , Liu Chun Hua
Published: December 2014

Ceramic plate is a new product in solar heat collecting. However, the heat transfer efficiency of the existing products is low. The optimization of the flow path and structure of solar heat collecting ceramic plate can strengthen the heat transfer greatly. This study aimed to obtain the optimization data of the heat transfer characteristics in order to design more efficient solar collecting system. The internal flow path and structure was modified based on the computational fluid dynamics and numerical heat transfer. The result has proved that the internal flow field was made uniform with little increase of the resistance loss, but achieved more efficiency of the heat transfer.
Energy Saving Potential on Centrifugal Water Chillers with Frequency Converter System: A Case Study in China
Authors: Liu Yuan , Wang Qi , Song Pu
Published: December 2014

In order to evaluate the energy saving potential during centrifugal water chillers’ operation, centrifugal water chillers from an industrial enterprise in China are investigated. Based on the actual operation data gained from 3 different water chillers, their working performances and the energy consumption situations are reported and researched in this paper. Meanwhile, the energy saving potential and economic performance of the chillers are also reported and analyzed, when the appropriate variable frequency systems are introduced.
Heat Recycling of PCS Power Inverter on Energy Storage Device
Authors: Li Ping Ping , Liu Hui , Zhang Zhi Qiang
Published: December 2014

Nowadays, energy storage technology is a new technology. In power generation field, energy storage technology can largely solve the problem of the randomness and volatility in the new energy power generation. This technology can realize smooth output of new energy power generation. It can effectively regulate the power grid voltage and frequency in the new energy power generation, and make the new energy power generation friendly connected to the electricity grid. It has great significance to energy conservation, environmental protection, power supply reliability improving, power grid efficiency improving, and resource utilization.
Combustion Behavior and Combustion-Supporting Mechanism of KMnO4 on Mixing Pulverized Coals and Semicoke in Blast Furnace Injection
Authors: Yang Zhi Yuan , Wang De Chao , Jiang Jin Lin
Published: December 2014

The static crucible method was employed to effects of different additions and coal mixing ratios on burning rate. The optimal amount was 4% and mixing ratio was Semicoke-Jincheng coal=7:3. XRD and TGA techniques were used to characterize combustion process. The combustion-supporting mechanism was that Mn7+(CO-)7 weakens the bridged bond binding force among carbon structure units and changes lattice structure. Heat storage preparation time is shortened which accelerates pulverized coal combustion.
Desulfurization Effect of High-Sulfur Weibei Coal of Assisted by Microwave Irradiation and Ultrasonic Wave
Authors: Yang Zhi Yuan , Wang Si Tong , Tan Chao , Li Yan Hong
Published: December 2014

The desulfurization process of high-sulfur coal in Weibei was studied by flotation pretreatment and microwave combined with ultrasonic wave and oxidants. Through the single factor experiment which took Chenghe coal as the sample, the optimum conditions of this process had been concluded as follows: microwave power was 250 W, microwave time was 15 min, ultrasonic temperature was 60 °C, ultrasonic time was 30 min, coal slurry concentration was 0.083 g/ml, coal particle size was less than 0.074 mm, the dosage of agents was 8 mL/g, the radio of acetic acid and hydrogen peroxide was 1:3. After fractional release pretreatment, the sulfur reduction of Chenghe coal could reached to 53.10%. As to Hancheng coal, the value was 46.41%. By analyzing XRD and XPS spectra, it showed that most inorganic sulfur were removed by flotation pretreatment, and under the function of microwave combined with ultrasonic wave and oxidants, a part of organic sulfur was removed, such as mercaptan, sulfoxide and thiophene. However, as for sulfone, the removal effect was not obvious. The results proved that the experimental method could remove most of inorganic sulfur and part of the organic sulfur and significantly reduce the coal ash.
Analysis on Failure of Oxide Layer of T91 High Temperature Superheater Tube
Authors: Zhang Shan Shan , Chen Guang , Li Chang Ming , Hu Da
Published: December 2014

The reason why the failure protective properties of the oxide layer of T91 high temperature superheater tube were analyzed in this study. The microstructure of the oxide layer of T91 high temperature superheater tube was observed by scanning electron microscope (SEM) and the morphological features of it was also analyzed. The concentrations of alloy elements in the section of internal tube were quantitatively analyzed using Energy Dispersive System (EDS). The results showed that the oxide layer of T91 tube can be divided into three layers: inner layer, middle layer and outer layer. The inner layer was formed by chromium rich oxide with compact structure. The middle layer was made up by porous oxide with loose structure. The outer layer was identified as Fe2O3. When the content of dissolved oxygen in steam was excessive, the apparent peeling marks will be appeared in the oxide layer of T91 high temperature superheater tube and the distribution of alloy elements in the oxide layer will present obvious proliferation, migration and enrichment phenomenon. Two different mechanisms (steam oxidation mechanism and oxygen oxidation mechanism) will exercise different influences on the structure and protective properties of the oxide layer: when steam contained dissolved oxygen, the oxide layer will be peroxidated by steam and the structure of oxide layer will be broken; When the tube was over-temperature operating, the oxide layer will be oxidated by oxygen.
Fast Charging Lead-Acid Battery Technology Theory Analysis
Authors: Li Kuang Cheng , Liu Zheng , Liu Ya Long , Liu Yan
Published: December 2014

Lead-acid battery has perfect characteristics, such as good performance, rich raw materials and low prices, it plays an important role as starting power and auxiliary power in vehicles, Because of inadequate understanding internal active material in physical or chemistry reaction in charging process or technical conditions of limit ,the charging methods mainly contents the constant voltage ,constant voltage the current limit, constant current .These methods fail to damages such as overcharging ,short-charging, gas chromatography and high electrolyte temperature. So, this paper analyzes concentration polarization and electrochemical polarization in fast charging based on the MAS theorems. However, pulse discharge technology can change the concentration of ions near the electrode, which speeds up the electrochemical reaction rate and increase the energy into the chemical energy efficiency.
The Experiment of Flushing Gelled Crude Oil which Stick on the Wall during Hydraulic Suspension Transportation
Authors: Li Fu Zhang , Liu Yang , Wang Zhong Hua , Wu Chuan Yan , Liu Xiao Yan
Published: December 2014

Gelled crude oil sticking on the wall during hydraulic suspension transportation will lead to large transport resistance and high energy consumption, such serious cases can cause pipeline plugging. In order to promote the technology of hydraulic suspension transportation of gelled crude oil, this paper built the text system of oil sticking on the wall, studied on effects of flushing pipe which oil sticking on with water directly, analyzed whether gelled crude oil sticking on the wall is uniform, the quantity of water for flushing , time for flushing etc the effects on flushing. Experimental results showes that, the effect of a few gelled crude oil particles sticking on the wall, being rinsed by cool water is good; the effect of flushing non-uniform sticking on the wall is better than uniform with large one. When the diameter of 53mm pipe’s wall adhesive 5mm thick (135g) of gelled crude oil (freezing point is 38°C), using the flow of 3.7 to 5.7 m3/h and water of 18°C to flush, the effects of flushing the uniform oil tube which oil stick on is between 2.8 to 5.9%, the effects of flushing the non-uniform one is between 9.5 to 23.3%; when the flow of tap water increased from 3.7 to 5.7m3/h, the quantity of flushed off oil uniform and non-uniform sticking on the wall was increased by 2.1% and 5.8%. For different types of flushing experiment, the effect is better in front 15min. Over time, flushing effect had gradually weakened, and the amount of flush out oil wasn’t increased significantly when time increased to 45min later.
A Variable Frequency Pulse Fast Charging Technique for Li-Ion Batteries Based on Fuzzy Control
Authors: Yang Meng Meng , Wu Tie Zhou , Wu Xiao Min , Zeng Yi Shi
Published: December 2014

To further shorten the charging time, enhancing charging efficiency and extending battery charge cycle life, this paper presents a variable frequency pulse fast charging methods based on fuzzy control depolarization. This method uses perturbation and observation method tracking resonant frequency real-timely and then finds the maximum current corresponding to the resonant frequency to charge the battery while using fuzzy control technology to detect and eliminate polarization effects arising from the charge process to accelerate the charging speed and realize frequency-varied fast charging. Experiments showed that using the fuzzy control frequency-varied pulse charging technique improves the charging time, charging efficiency, and rising temperature of the Li-ion battery by about 6.9%, 2.4%, 17.3%, respectively, as compared with the currently used fast charging method of intermittent alternating current.
Calculation of Complexion in Chemical Precursor for ZnSe as Buffer-Window Layer of CIGS Solar Cell
Authors: Chen Liang Yan , Fang Chao , Chen Xi Qu
Published: December 2014

With ammonia and hydrazine hydrate as complexing agents, ZnSe has been deposited as the buffer-window layer of solar cells from chemical solution, in which the complexion played vital role in controlling the film growth. We calculated various complexion in chemical solution deposited ZnSe precursor with solubility theory. And the main complexion and their concentration with adding of complexing agents and pH value have been investigated. And we found that the main complexion are Zn (NH3)32+ and Zn (NH3)42+, the concentration of which varied with the adding of ammonia and pH value.
Photovoltaic Performance and Long-Term Stability of Hybrid ZnO/TiOPc Solar Cells with DH-α6T as an Electron Blocking Layer
Authors: Ye Rong Bin , Yanagida Manami , Ohta Koji , Baba Mamoru
Published: December 2014

This article reports on photovoltaic performance and long-term stability of hybrid solar cells based on ZnO/TiOPc with DH-α6T as an electron blocking layer. When the thermal annealing temperature (TA) was increased from 120 °C to 180 °C, these absorption spectra of TiOPc thin films reveal the gradual formation of the crystalline α-phase, as evidenced by the development of a red-shifted absorption band, peaking 845 nm, and the corresponding reduction of the 720 nm amorphous phase peak. Device performance of hybrid solar cells could be improved and open-circuit voltage (VOC), short-circuit current (ISC) and power conversion efficiency (η) were enhanced by thermal annealing, which originated from amorphous TiOPc films transformed into crystalline α-TiOPc films with a wider red and near-IR absorption band. At TA= 150 °C, the device achieved the highest performance with VOC, ISCand η of 0.53 V, 1.71 mA/cm2, and 0.29 %, respectively. Furthermore, the hybrid device showed long-term stability that this device maintained over 55 % of its initial η after 300 days aging at room temperature.
Study on the Electrical Properties and the Ac Conductance Response of ZnO-Based Varistor
Authors: Zhao Xue Tong , Liao Rui Jin , Li Jian Ying
Published: December 2014

ZnO-based varistor ceramics with different recipes were prepared in this research. It was found that the grain growth was restrained with the addition of Ba2+. SEM results indicated that the grain size of ZnO varistor ceramics with Ba2+ was reduced to 4.7 μm. Correspondingly, the breakdown electric field of the ZnO varistor samples were extremely enhanced to 8730 V/cm. The results of ac conductance response showed that two relaxation peak 1 and 2 with activation energy at about 0.24 eV and 0.36 eV were observed in 100-250 K, which were not affected by additives. However, a new conductance relaxation peak 3 in 300-450 K for sample B and C can be found, whose activation energy were varied from 0.55 eV to 0.65 eV with the addition of Ba2+. It was put forward that the electrical properties of ZnO varistor ceramics may be associated with the conductance relaxation peak 3.
The Feasibility Study of Distributed Photovoltaic Power Generation System in Western Region of China
Authors: Li Gang Sheng , Zhang Yi Na , Xia Long , Zhou Chen
Published: December 2014

Due to the natural environment, geographic location, the technical conditions and restrictions of many factors, centralized parallel operation of power grid the west extension and popularization in our country with high difficulty and feasibility. The distributed photovoltaic power generation possesses the following advantages: less investment, flexibility and compatibility. The joint operation of DG with power grid brings tremendous variation in control and operation for modern power system, ultimately the stability of power supply is enhanced and the life quality of residents is improved in western region of China. This paper explores the operation mode of distributed photovoltaic power generation in remote areas, and introduces the concrete operation mode of the project, analyzes the adaptability of distributed photovoltaic mode. Finally, the feasibility of the application of the distributed photovoltaic power generation in the western region of China is analyzed in this paper.
A New Fault Location Method for Distribution Network Based on Traveling Wave Theory
Authors: Wang Jing , Liu Xiao , Pan Zhi Yuan
Published: December 2014

The conventional approaches to distribution network fault location has certain drawbacks in terms of complexity, especially the fault occurred in the branch lines. In this paper, a novel fault location method based on D-type traveling wave was proposed. This method choose the measurement point which the initial traveling waves first reached as the reference measurement point, and the distance between multiple failure points received a fault traveling wave signal to the reference measurement point was calculated. Then, the maximum distance between multiple failure points to the reference measurement point was selected as location of the final failure point. The simulation result with ATP simulation software and MATLAB software show that the proposed method can achieve fault location fast and accurately within a very short period. Compared with the existing algorithms, this method was consistent whether the fault occurred in the main line or branch lines, which improved the accuracy and reliability of the traveling wave fault location in distribution network.
A Novel Adaptive Preconditioner Based CPF-GMRES Algorithm
Authors: Zheng Hao , Zhao Jin Quan , Men Kun , Yin Jian Hua , Hong Chao
Published: December 2014

This paper presents a novel CPF-GMRES algorithm based on an adaptive preconditioner to overcome the computational bottleneck in the analysis of large-scale power system voltage stability with CPF. Considering the combination details of CPF and GMRES, an adaptive preconditioning structure is proposed to reduce the formation times of preconditioner. Initialize the preconditioning matrix in the predictor of CPF, and modify it with Broyden method in the corrector. Large number add-in strategy and a replenished one are applied to deal with the influence of PVPQ bus-type switching. Numerical results with IEEE 118-bus test system and a real power grid verify the effectiveness of the proposed algorithm, and indicate that a remarkable speed advantage is obtained compared with the conventional CPF-GMRES with the preconditioner of ILU factorization.
Speed Control System Model Parameter Error Evaluation Based on PMU Data
Authors: Zhang Wen Chao , Gu Xue Ping , Liang Hai Ping , Hao Yu Qia , Wang Sai
Published: December 2014

Power system dynamic simulation is an effective way to fully grasp the power system dynamic response, and it is also the basis guiding power system planning, design and operation. The operation of the generator characteristics determines the dynamic characteristics of the power system to some extent, so enhancing the accuracy of generating set model parameters has great significance on improving the reliability of power system dynamic simulation. Due to the operation of the power system characteristics and special requirements on the safe and stable operation, we cannot understand its correctness of dynamic response by means of exerting disturbance test, which limits the simulation error evaluation work of the generating set. PMU data from effective disturbance scenarios is used in this paper to study the realization of the generator speed control system of hybrid simulation technology based on data measured by PMU. The corresponding hybrid simulation program is developed by using C++. The evaluation of speed regulation system error of the model parameters is realized on the basis of the simulation error index. The validity of speed control system model parameter error evaluation methods is proved by PMU data measured from disturbance scenarios of four Units in an area.
Comparative Analysis of the Calculation Results of Online Short-Circuit Current Based on PSASP and Fault Wave Recording
Authors: Lu Guang Ming , Zhang Wei , Yan Jian Feng , Yu Yong Jun , Yu Zhi Hong , Qin Yan Hui , Lv Ying , Li Wei , Sun Shu Ming , Xie Chang , Dai Hong Yang
Published: December 2014

In daily operation process,the results of online short-circuit current calculation and fault wave recording is different, the differences between the two results affected the dispatcher’s decision. In-depth analysis of the calculation process and finding the possible causes of the differences should be done. The on-line PSASP short-circuit current calculation based on power flow and scheme was studied. The boundary conditions and calculation models of two methods were studied, the influence of the modeling scope and equivalent circuits to the short-circuit current was also studied. Fault wave recording calculated short-circuit current through forward calculation, the middle to both sides calculation and backward calculation, and the differences of the three calculation mode were also analyzed. Through the above analysis and comparison, online data equivalent to 220kV high voltage side of the transformer greatly impacts short-circuit current, but effective value calculation method of fault wave recording has a little impact on the short-circuit current, mainly in the following reasons, the first one is that non-dispatching power plant is equivalent to a load, the second one is that several different types of load is equivalent to a load using one load model, the third one is that all devices connecting to low voltage side of the 220kV transformers are equivalent to 220kV. Conclusions of the analysis can provide the basis for the practical work of online short-circuit current calculation.
Effectiveness of the Automation Selection of Water Treatment Technology in a Particular Water Source
Authors: Boronina Lyudmila , Sadchikov Pavel , Tazhieva Svetlana , Usynina Anna , Moskvichiova Elena
Published: December 2014

This paper propose the realization of the automated control system for the selection of the optimal water treatment system. This selection is determined by the level of background and man-made pollutants and based on the set of classifiers. All these aspects uniquely define the equipment composition and processing chain of the water treatment construction.
Landscape Assessment Analysis of City Road for Yingbin Avenue in Hong’an
Authors: Gao Jie Yu
Published: December 2014

The city trunk roads are the main landscape lines in cities. The main features of the line are horizontal landscape factor features, vertical landscape factor features and road furniture factor features. Under the condition of analyzing the major dependent landscape factors by the landscape index analysis,this treatise takes an the city trunk toads in Hong’ an, Hubei as an example to obtain quantitative sensory results.and specific landscape indexes conclusions by expert scoring and fuzzy analyzing, and to instruct the city landmark linear landscape specifically.
Evaluation of the Eco-Environmental Quality and its Index-Induced Influencing Factors in the Yangtze River Delta Urban Agglomeration
Authors: Yang Fang , Liu Min , Jia Wen Xiao , Lin Lin , Xiang Wei Ning
Published: December 2014

This paper aims to provide a clear understanding of the characteristics and spatial-temporal pattern of the eco-environmental quality (EEQ) in the Yangtze River Delta Urban Agglomeration. Based on the 500m × 500m pixel scale, the evaluation was carried out using the Ecological Index (EI). Results show that the EEQs are both classified into “Moderately high” level in 2005 and 2010. It exhibits obvious spatial variability with Shanghai-Nanjing belt as a demarcation belt, indicating that EI values are higher in the south and lower in the north while EEQ in the belt is the worst. Further research demonstrates it is policy-induced emission reduction that gave rise to the overall eco-environmental improvement from 2005 to 2010, followed by an increase in the volume of water resources and green space. The EEQs of Shanghai, Jiaxing, Nantong, Lianyungang, Yancheng and Xuzhou are more constrained and influenced by EI-related factors.
Industrial Organization Pattern Based on Comprehensive Benefit of the Ecologically Fragile Region in the West of China
Authors: Cai Shao Hong , Liu Wen Jiang , Jiao Jian Jun , Lu Yang
Published: December 2014

In the new historical era, the ecologically fragile region in the west is facing with two major tasks of rapid development and green development. Through a model of comprehensive benefit, we analyze the benefit differences among several industrial organization patterns, and point out that the pattern of circular industrial cluster brings out the most comprehensive benefit and the best organization advantages. It is therefore the optimal industry organization pattern in the ecologically fragile region in the west of China.
Energy Efficiency Measures for a High-Tech Building with a Solar Roof
Authors: Lin Yao Lin , Yang Wei , Liu Ming Sheng
Published: December 2014

This paper presents the implementation of energy efficiency measures in a building that consists of office, lab and clean room area. Total Performance Oriented Optimization and Retrofits (TPORs) were implemented. 594 kW solar panels were installed on the roof and connected to the electrical grid during the optimization process. Ten power meters were installed throughout the building to measure the total building electricity demand, solar generated electricity demand, HVAC and non-HVAC-equipment demand to quantify the energy savings from the implementation of the energy efficiency measures and savings from the solar panels. The electricity savings from optimization on the HVAC system is about 7,209,000kWh/year (194.4kWh/m2-year), which is about 30% of the total building electricity consumption with peak demand reduction of 935 kW. There savings come from the solar panel is 811,925 kWh/yr; however, it effectively reduced the peak electricity demand by 302.6 kW.
The Study on Eco-Folk House Design of Mountainous Village in Southern Shaanxi
Authors: Wei Na , Wei Jia , Wang Wei
Published: December 2014

Take the ecological folk house design in Li Jiayuan village in Shaanxi province for example, this paper investigates and explores the actual existing problems and shortcomings in rural folk house, analyzes its influence mechanism. On this basis, transform the plane layout and form of the traditional folk house from the perspective of ecology and technology, put forward the design strategies and schemes to suit the local folk house to improve rural residents quality of life, reduce energy consumption of buildings and preserve the ecological environment, hopes to provide reference of the ecological folk house construction in mountainous village.
Formation Kinetics of Regenerated Cement Clinker Calcined by Using Wasted Recycling Concrete Powders as Raw Meals
Authors: Zhang Jie , Zhou Zong Hui , Cheng Xin
Published: December 2014

Artificial aggregates with high strength and a similar mineral composition to Portland cement clinker are made up of industrial waste and limestone, which are prepared for recycling concrete. Regenerated cement clinker is fabricated by recycling concrete powder added with a small amount of correction raw materia. Through the Gentling equation computing and microstructure morphology observation, the apparent activation energy (Ea) of two kinds of regenerated cement clinkers are 199 kJ/mol and 333 kJ /mol respectively, which is lower than that of traditional cement clinker (518 kJ/mol). The reaction rate constant (k) of regenerated cement clinker are about 4.8108×10-5 s-1 and 2.5003×10-5 s-1 at 1350°C. At the process of calcination, the formation temperature of C3S and sintering temperature of regenerated cement clinker are lower than that of the traditional cement clinker.
Effectiveness Analysis of City Expansion in the Southeast of Changchun City to Economic Development Based on DEA
Authors: Song Dan , Jiang Qi Gang
Published: December 2014

Under the background of rapid urbanization in China, this paper takes the southeast of Changchun city as an example, and uses 2008 to 2012 as decision making unit with DEA. Then it comes to the relevant conclusion of the effectiveness of urban expansion in Changchun city to the economic development:(1) the southeast of Changchun city may still have the space to continue expanding;(2) whether urban expansion in the future still brings more benefits to Changchun economic development or not, which mainly depends on the evaluation result after 2012;(3) DEA method has the feasibility and effectiveness in this respect, and such studies can be assumed to be one of the reference of determining city scale.
Investigation and Study on the Reconstruction of Urban-Village in Xiaogan
Authors: Hu Hong , Yao Da Fei , Yang Zi Jiang
Published: December 2014

Through the investigation on the reconstruction of urban-village in Xiaogan City, to study the experiences and difficulties during the process, then, proposed a possible improvement measures .
The Cost-Benefit Analysis for the Evaluation of Public Infrastructure Projects - The Case of the Subway of Potenza
Authors: Manganelli Benedetto
Published: December 2014

In the present work the economic feasibility of a project of public infrastructure, the expansion of the subway of the city Potenza, is estimated. The assessment has been developed through the application of the Cost-Benefit Analysis. As is known the advantage of this technique is the ability to express in monetary terms the externalities (positive and negative) generated by the project. In this case, the external cost savings related to the improvement of the mobility in the city have been internalized. The research has shown that the valuation of the externalities can be an effective way to manage the planning of new public transport infrastructure.