bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on Heat Storage-Release Property of Rectangular Array Tube Encapsulated Heat Storage Device
Authors: Tian Hai Chuan , Niu Jian Hui
Published: October 2014

based on previous studies heat storage device structure was optimized and a rectangular tube array encapsulated phase change heat storage device was designed. Compared to sleeve heat accumulator, the heat transfer area was increased 2 times and phase change material thickness was reduced, which has greatly reduced the thermal resistance and improved the heat transfer coefficient. Thermal performance experiment bench of phase change heat storage device was built; heat storage performance experiment was carried on and the results were analysed.
Research on Operation Optimization of Industrial Boiler by Principal Component Analysis
Authors: Wang Wen Biao , Chen Lan , Wang Xu Dong , Pei Ji Bin
Published: October 2014

Abstract. Thermal efficiency is an economical operation index of industrial boilers. There are many factors influencing thermal efficiency. It is difficult to keep the boiler in high efficient operation just using single automatic control method when environment has been changed. Therefore, the control of combustion systems is usually depended on artificial experience. To improve this situation, an operation optimization method is proposed. An identification model which can reflect the thermal efficiency is established by using principal component analysis based on historical data. When the boiler’s operation efficiency decreases, the parameters of influencing boiler efficiency can be directly got by contribution plot method, which can guide operators in real-time to adjust these parameters maintaining boiler efficient operation.
Abstract. Thermal efficiency is an economical operation index of industrial boilers. There are many factors influencing thermal efficiency. It is difficult to keep the boiler in high efficient operation just using single automatic control method when environment has been changed. Therefore, the control of combustion systems is usually depended on artificial experience. To improve this situation, an operation optimization method is proposed. An identification model which can reflect the thermal efficiency is established by using principal component analysis based on historical data. When the boiler’s operation efficiency decreases, the parameters of influencing boiler efficiency can be directly got by contribution plot method, which can guide operators in real-time to adjust these parameters maintaining boiler efficient operation.
Analysis of the Movement of the New Wave-Energy Dynamoelectric Equipment
Authors: Liu He Ping , Ma Wen Tao , Luo Ani , Wang Long Kun , Wang Yuan Yuan , Zhang Qing Hua
Published: October 2014

The new wave-energy dynamoelectric equipment has small volume and its transportation is very relaxed for application in the wide ocean area etc. So it has certain competitive power and enhanced researching value. After analyzing the structure of the equipment, it is found that the displacement difference between the floater and reducing-velocity structure validates feasibility and efficiency of the equipment. In this paper, the displacement difference is mainly researched. At first, forces on the upper and lower parts are analyzed respectively. Then investigating their movements, some structural parameters are determined. At the same time, the problem that the discontinuous acceleration change of the movement of the reducing-velocity structure causes the impulsion to the whole equipment is found. In order to solve the problem, the solution that a spring is added to the connecting string is adapted. The improved equipment is checked and finally it is found feasible.
Compressor Performance Curve Extrapolation Method Based on the Similarity Theory
Authors: Wang Zhi Tao , Bai Bing , Li Shu Ying , Yang Qing Cai , Wang Meng Qi
Published: October 2014

Due to the fact that the low speed pump similarity theory is only applicable to incompressible fluid, this theory cannot be used for extrapolation of compressor performance curve. Considering the compressibility of working medium; therefore, this paper has modified the similarity theory and put forward a new index relationship equation. The two low speed performance lines which are already known were used to get the similar working points and extrapolate the performance lines through the optimization method. Compared with the existing performance lines, the results show that the method is simple, convenient and qualified with practicability and accuracy. This method plays an important role on studying startup process of a gas turbine and improving the accuracy of the simulation of startup process.
Multiple Models Fuzzy PID Controller Design in Ship Power System
Authors: Jiang Hang , Wang Xin , Wang Li Ming
Published: October 2014

The ship power system is a complex system with time varying, nonlinear and strong coupling characters. The traditional PID controller is difficult to meet the requirements of the system.In this paper, a multiple models fuzzy PID controller is designed. Considering the different operating conditions of on-land ship power system, two excitation regulation model which respectively corresponds to a fuzzy PID controller are set up. Each time, based on the input operation condition tested, only one fuzzy PID Controller is chosen to improve the control precision. At the end, simulation results show that multiple model fuzzy PID controller is superior to the single fuzzy PID controller, which effectively improves the transient response of the system, the steady state accuracy and robustness, having good prospects for engineering applications.
MV “CRYSTAL STAR” Diesel Turbocharger Surge Cause Analysis and Troubleshooting
Authors: Li Bin , Zhang Shou Jun
Published: October 2014

Currently shipping costs are increasing sharply due to the rising oil prices. In order to reduce shipping costs, most low-speed two-stroke diesel engines run at low speeds to reduce fuel oil consumption, and this measure might result turbocharger surge. For modern marine diesel engines, the exhaust gas turbochargers are becoming more and more important; their working conditions have a direct impact on the performance of diesel engines, consequently affecting the operation of the ship. Surge will fail a turbocharger to achieve the supercharging ratio, damage the turbocharger components and even lead to a damage accident of the whole turbocharger. Therefore, a good understanding of the reasons for marine diesel engine turbocharger surge will help to prevent and eliminate turbocharger surge in operation. This paper is to make an analysis on the special surge mechanism occurred to the turbocharger on MV "Crystal Star", and propose some appropriate supervisory and preventive measures against the problem.
Research on the Measuring and Calculating Methods of the Relative Internal Efficiency for Steam Turbine
Authors: Jin Jian Guo , Cui Wan Ting , Yu Jing Wen
Published: October 2014

The relative internal efficiency for steam turbine is one of the main economic indexes in evaluating the economic operation of steam turbine. It is usually obtained by thermal performance tests or online monitoring. In power plants, by means of measuring and calculating the relative internal efficiency for steam turbine, steam turbines’ thermal economy can be analyzed and diagnosed, and the safe operation and energy saving work can be directed. But there still exist some problems in measuring and calculating the relative internal efficiency for steam turbine at present. In this paper, the two defining methods of the relative internal efficiency are analyzed and compared. The connection of two kinds of relative internal efficiency and the same effect in evaluating the operation economy of steam turbines are indicated.Key words : Steam Turbine; Thermal Performance Test; Economic Index ;Relative Internal Efficiency
Performance Model Development for the Adjustable Blades Axial Flow Fan Based on Multivariate Polynomial Fitting
Authors: Song Dong Hui , Hua Liu Peng , Li Shao Hua
Published: October 2014

To obtain a performance model for the adjustable blades axial flow fan, the performance surface of fan was fitted using binary polynomial fitting method, and the coefficients matrix was solved with QR decomposition. By comparing the fitting results show that the fitting effect is good when the 5 order polynomial was used to fit the performance surface of the fan and the 6 order polynomial was used to fit the boundary of performance surface. The accuracy of the obtained model can meet the requirements of the engineering application and scientific research.
Research Progress in Natural Frequency Calculation of Heat Exchanger Tube Bundles
Authors: Xi Guan Nan , Shi Chao , Zou Shuai , Cheng Zi Yang , Deng Yong
Published: October 2014

Natural frequency in tube bundles is the basis of vibration analysis in the heat exchanger. The calculation methods of the natural frequency are summarized in four type of tube bundles: straight tube, U-bend tube, finned tube and tube-fin. The influence of structure, temperature and fluid on the natural frequency are analyzed. Some anti-vibration measures are also put forward. The research direction of vibration analysis in tube bundles of heat exchanger in the future has good prospects.
Hot Air Ignition Characteristics of Cotton and Corn Straw Pellet Based on TG-DTG
Authors: Cui Yong Zhang , Qu Yun Xia , Tang Ming Tian , Gao Peng , Zhang Guo Kai
Published: October 2014

In this paper, using TG-DTG and single pellets hot air ignition experiment to study the hot air ignition characteristics of biomass forming granule, analyzes the hot air temperature, velocity, flow rate of its influence on ignition performance. It was found that the weight loss rate of surface material significantly higher than the center materials of the pellet at different heating rates through the experiment, and lignin pyrolysis accelerated leading to substantially coincide of hemicellulose, cellulose and lignin pyrolysis, With the increase of air temperature, maximum weight loss rate increased, the pellet heating rate accelerated, sped up the pellet ignition, the ignition temperature should be above 500°C. As the increase of gas flow, the weight loss of corn stalks is reduced after increased first, little change in the final weight loss. Weight loss rate is decreased first and then increased. The maximum weight loss rate is essentially the same at low flow, but the maximum weight loss rate reduced and the time extension after more than 50ml/min.
Analysis on Thermal Comfort of Air-Conditioned Buildings in Malaysia: Case Study of Universiti Tenaga Nasional
Authors: Asadi Iman , Hussein Ibrahim , Palanisamy Kumaran
Published: October 2014

Field study was carried out on the thermal conditions and thermal comfort of occupants in air conditioned buildings in Malaysia. The study was carried out in 10 staff offices and 6 student study areas of Universiti Tenaga Nasional (UNITEN) during October and November 2013, collecting a full set of objective physical measurements and subjective assessments through questionnaires. The measured environmental parameters were air temperature, relative humidity and air velocity. The subjective responses concern the judgment of the occupants about the thermal environment at the moment of measurements. The obtained results showed that most places are in acceptable and comfort zone according to Fanger’s predicted mean vote (PMV) model. The neutral air temperature obtained through linear regression analysis of thermal sensation vote (TSV) is 23.9°C for UNITEN. The result of this study demonstrates that the acceptability of thermal comfort among UNITEN occupant is about 78 %.
Dynamic Behavior of Air Condition System and Temperature Control Analysis
Authors: Wang Jing , Geng Shi Bin , Han Xu , Zhang Hua
Published: October 2014

A procedure for deriving a dynamic model of an air condition system was described in this paper. The system consisted of a zone, cooling coils and fan. Room thermal balance model and dynamic model of AC control system components including sensor, cooling coils and ducts, were established. This model accurately predicts the effect of inlet air temperature during closed loop control of output air temperature using chilled water flow rate as a control input. Fuzzy adaptive control (FAC) combined with proportional integral derivative (PID) control algorithms (FAC-PID) were used to control the chilled water flow rate. Computational simulations were carried out in toolbox Simulink of Matlab. The fuzzy parameters were carefully tuned to produce less oscillatory responses. The results show that the system based on FAC-PID control is capable of controlling the disturbance efficiently with less time lag and small error than PID control.
Research Based on the Actual Project of Central Air Conditioning Intelligent Frequency Conversion System
Authors: Lv Yan Ling , Teng Chong , Chen Wen Hai
Published: October 2014

At present, with the development of science and technology, central air conditioning systems had made great progress. Because of the earlier central air conditioning system have some shortcomings. Such as hunge energy consumption, water cycle equipment wear. Now engineer put forward a variety of solutions. One of the most mainstream solutions is technology of frequency conversion water cycle central air-conditioning system and the central air conditioning system of intelligent sending wind energy saving technology. This design is for central air conditioning system of a company's actual renovation project. It is equipped with technology of frequency conversion water cycle central air-conditioning system. Mainly consist of the control part, frequency converter part and the water cycle part. This paper firstly introduces the working principle of general frequency converter PID control central air conditioning system. And from the control cabinet part, motor start part, PLC control part, and the frequency converter set part introduces the design. And analyzed the operating results. Because of using negative feedback, the temperature of system become stable. Through PLC intelligent control, can also make the system more energy conservation and environmental protection. Through the analysis of the actual system running data, verified the system has a considerable energy saving ability.
Study on Performances of Refrigeration-Type Compressed-Air Dryers Using Environmentally-Friendly Refrigerants R717, R290 and R600a
Authors: Liu Hui , Xiao Hong
Published: October 2014

The coefficient of performance (COP), the volumetric refrigeration capacity and the pressure ratio of the refrigeration cycle were calculated for a refrigeration-type compressed-air dryer using natural environmentally friendly refrigerants R717, R290 and R610a and compared with those using R22. Study shows that in the working condition of a refrigeration-type compressed-air dryer the COP and volumetric refrigeration capacity using R717 are 5% and 11% higher than those using R22 respectively and COP using R290 is equal to 98% of COP using R22 and the volumetric refrigeration capacity is equal to 85% of that using R22. Although COP using R600a is 2% higher than that using R22, the volumetric refrigeration capacity is much lower than that using other refrigerants above mentioned. R717 and R290 are recommended as appropriate substitute refrigerants for R22 in a refrigeration-type compressed-air dryer.
A Study of Cooling Load Calculation of Stratified Air Conditioning System for Large Space Based on the Simultaneously Solving Model
Authors: Cai Ning , Huang Chen
Published: October 2014

A calculation method for cooling load of stratified air conditioning system based on the simultaneously solving model is presented. Thermal environment experiment under summer condition is carried out in a large space building, indoor air temperature, inner wall surface temperature and cooling capacity were obtained; the stratified air conditioning cooling load calculated by the simultaneously solving model is compared with air conditioning cooling capacity in experiment, the relative error is 14%, taking the loss of cooling capacity and leakage loss, it can be thought that the simultaneously solving model can be used to calculate cooling load of stratified air conditioning system.
Research Progress in Electro-Hydraulic Position Servo Controller
Authors: Xi Guan Nan , Li Jian , Sun Chun Ya , Zhang Yuan Yuan , Tang Tong Ming
Published: October 2014

The electro-hydraulic position servo control system is a typical complex nonlinear system. It is difficult in achieving the control which has high quality performance.To overcome the effects of non-linearity, parameter uncertainty, external disturbances and load changes, the design of controller is particularly critical. This paper summarizes the controllers which are applied widely: PID controller, fuzzy controller, neural network controller and hybrid controller. Additionally, the paper analyses their performances. At the same time, this paper also points out the prospects of the controllers.
The Study on Promotion of Chinese Green Energy-Saving Buildings
Authors: Li Wei Fang
Published: October 2014

The promotion of the green buildings is the necessary way to expand Chinese urbanization. The idea of green energy-saving building and green life-styles should be a kind of behavioral patterns. In the paper, the idea of green and energy-saving buildings is put forward. The management systems about green and energy conservation buildings are combed. Some Problems existing in the promotion of Chinese green energy-saving building at present are pointed out. From the perspective of implementation, some countermeasures are also pointed out in the paper, including improving supervision about green energy-saving buildings, perfecting technology system of intelligent and green energy conservation buildings, based on optimizing the design, setting up scientific assessment system, promoting the use of new technologies, new materials, and so on.
Research on Improved CCHP System Based on Comprehensive Performance Evaluation Criterion
Authors: Chen Fei Xiang , Xu Jian Qun , Li Zhao Yu , Liu Ming Tao
Published: October 2014

In view of energy consumption characteristics of a typical industrial park, to further improve the low-grade waste heat utilization of CCHP system, an improved CCHP triple-generation system (ITRI) equipped with thermal storage device (TSD) and electric chiller (EC) is proposed. A comprehensive performance evaluation criterion (CPEC) is established, the capacity of triple-generation system is configured by using nonlinear programming method. A hybrid operating mode optimization strategy is proposed based on the different CPEC values of different operating mode. The results demonstrate that: after adopting ITRI, compared with traditional triple-generation system (TTRI), although annual cost increased by 0.63%, the primary energy consumption rate and lower carbon dioxide emissions decreased by 5.45% and 3.72% respectively, CPEC value increased by 19.7%. This paper has a theoretical guidance for design of triple-generation system in new industrial park and has a certain reference value for operating mode optimization of triple-generation system in the industrial parks which has been built.
Numerical Modeling of Thermogravitational Convection in Air Gap of System of Rear Ventilated Facades
Authors: Petrichenko Mikhail , Vatin Nikolai , Nemova Darya , Kharkov Nikita , Korsun Artem
Published: October 2014

Results of numerical modeling of thermogravitational convection are presented in article in an air layer of systems of rear ventilated facades, dependences of velocity of air and stream temperature on geometrical parameters of an air gap are received.
A Wavelet-Based Method for Automatic Location of Peaks in Gamma-Ray Spectra
Authors: Xiong Cen , Liu Shu Huan , Li Yong Hong , Tang Du , He Chao Hui
Published: October 2014

Wavelet analysis method is a promising tool for analysis of gamma-ray spectra due to its time-frequency localization ability and multi-scale resolution feature. This paper describes a method to locate peaks in gamma-ray spectra based on continuous wavelet transform (CWT) of the spectrum using Marr wavelet. The theoretical basis of using Marr wavelet to detect Gaussian peaks was explained. A scale range, 1 to FWHMmax+2, was then suggested to perform CWT. Several novel criteria were used to discriminate real peaks from noise. The detection ability of this method was verified with some measured spectra. The results indicated that Marr wavelet did well in locating gamma-ray peaks.
Modeling and Evaluation in an Interworking of WLAN and WiMAX Network
Authors: Wang Ye , Niu Jing , Huang Xiao Yan , Cheng Yan Ming
Published: October 2014

The complementary characteristics of Worldwide Interoperability for Microwave Access (WiMAX) and IEEE 802.11 Wireless Local Area Network (WLAN) networks make them attractive for integration to offer the best of both technologies. However, in order to make the integration effective, the in-depth mobility study by simulation is necessary. This paper addresses the simulation models for mobility management procedures in an interworking of WiMAX and WLAN network for the various integration scenarios. The mobile multihomed node models of WiMAX and WLAN interfaces are developed and simulated in various traffic environments and network integration topologies including group mobility and MANET. The simulation results show that the developed models are useful for mobility studies in various integration wireless networks.
Application of Recurrence Plot to Wind Power Predictability Study under Different Sampling Intervals
Authors: Yang Mao , Qi Yue
Published: October 2014

The accurate prediction of wind power is an important way to improve the safety and economy of wind power system operation in large scale. On one side, the accuracy of wind power prediction depends on the characterized degree of accuracy for wind power fluctuations under the used prediction method. On the other side, it depends on the inherent degree of predictability in the characteristics of wind power fluctuations. This text will focus on the predictability of wind power, and use recurrence plot and recurrence rate to analyze it in the qualitative and quantitative view, and analyze change rule of recurrence plot and recurrence rate under different time scales. The real case of a wind farm has been analyzed to demonstrate that predictability of wind power will be poorer when the sampling interval becomes large.
The Design and Implementation of Android-Based Mobile Learning Platform
Authors: Li Cui Mei , Hang Le , Wang Rou
Published: October 2014

Nowadays, with the rapid development of mobile computing technology, mobile learning, a brand new distance learning model, arises at the historic moment. As a new research field, learners could acquire knowledge that they wanted anytime anywhere and really control their learning progress based on its advantage. Android is a Linux kernel–based operating system which can be applied in multiple mobile terminal devices such as smart phones, tablet computers,etc.Based on the combination of mobile communication technology and mobile learning theory, firstly, this paper constructed the mobile learning platform architecture, then, it analyzed the function modules of the system client and the system server, finally, it realized the design of mobile learning platform which is based on Android system. This work would provide a guidance of the theory, method and practice in the development and design of mobile learning systems.
Applied Research of Convertible Wind-Solar Hybrid System on Matlab
Authors: Xu Hui Yi
Published: October 2014

This paper designed the wind-solar hybrid electricity generation system, it might offer users reliable power supply when the climate and other factors change. The system has a variety of operation modes, can be either manually or automatically transforms. Each mode can be selected manually switching storage batteries to achieve the reliable power supply and prolong the battery service life. Through Matlab simulation analysis, the feasibility of the control system has been verified. Simulation results show that the system output stability, it can satisfy user demand.
Assessment and Optimization of the Low Carbon Benefits of the Technical Transformation Projects for Loss Reduction in Power Networks
Authors: Zhang Jie , Li Yun Feng , Yang Yun Hua
Published: October 2014

In the context of low-carbon economy, this paper analyzes the necessity of technical transformation of the loss reduction in power networks. A low-energy-consumption benefit evaluation model was established for some technical transformation projects for loss reduction, so was a low-emission benefit evaluation model for loss reduction measures. Through field survey and statistical computation, the CO2 emission reduction potential of a selected power supply company, by adopting technical transformation for loss reduction, was comprehensively assessed. On this basis, the optimization of low-carbon technical transformations for loss reduction in plan and construction, operation and maintenance, and management and administration was put forward, in order to realize the mentioned CO2 emission reduction potential of the company.
Construction of the Factors Affecting China's Hydropower Projects and Overseas Investment Risk Assessment Index System
Authors: Ge Su Juan , Shi An Na
Published: October 2014

In this paper, power projects overseas investment risk as the research object, starting from the risk assessment and prevention, integrated use of risk theory of knowledge, power projects overseas investment to do a systematic risk identification and analysis. On this basis, the analytic hierarchy process, fuzzy comprehensive evaluation of knowledge and econometrics to establish risk assessment model, a comprehensive assessment of power projects overseas investment risks.
Energy Consumption Forecasting in Hong Kong Using ARIMA and Artificial Neural Networks Models
Authors: Lai Sue Ling , Liu Ming , Kuo Kuo Cheng , Chang Ray
Published: October 2014

There have been considerable efforts contributed to the development of effective energy demand forecast models due to its critical role for economic development and environmental protection. This study focused on the adoption of artificial neural network (ANN) and autoregressive integrated moving average (ARIMA) models for energy consumption forecasting in Hong Kong over the period of 1975-2010. Four predictors were considered, including population, GDP, exports, and total visitor arrivals. The results show most ANN models demonstrate acceptable forecast accuracy when single predictor is considered. The best single input model is the case with GDP as predictor. Population and exports are the next proper single inputs. The model with total visitor arrivals as sole predictor does not perform satisfactorily. This indicates that tourism development demonstrates a different pattern from that of energy consumption. In addition, the forecast accuracy of ANN does not improve considerably as the number of predictors increase. Findings imply that with the ANN approach, choosing appropriate predictors is more important than increasing the number of predictors. On the other hand, ARIMA generates forecasts as accurate as some good cases by ANN. Results suggest that ARIMA is not only a parsimonious but effective approach for energy consumption forecasting in Hong Kong.
The Characteristics of China's Hydropower Projects Overseas Investment Risk and Possible Countermeasures
Authors: Shi An Na , Ge Su Juan
Published: October 2014

In the sustained rapid growth of the international economy, foreign investment and international business is becoming the next mainstream context, China vigorously implement the "going out" strategy, encouraging foreign investment. With economic growth, the rapid growth of the world's water and electricity consumption are also in the growing strength of China's hydropower companies powerful premise, accelerate the development of hydropower projects overseas investment is an inevitable trend. This is not only of significance for the development of major hydropower companies, while the international operations of Chinese enterprises to China’s energy security, energy policy have far-reaching implications. But the ever-changing international situation and uncertainty investment host country's investment environment for foreign investment in hydropower projects risk assessment and prevention challenges. Hydropower projects overseas investment risks should not be underestimated, risk assessment and prevention of improper investment will bring huge losses. This paper studies the characteristics of China's hydropower projects overseas investment risks and prevention.
The Research on Index System of Economic Society Development Based on the Medium and Long-Term Power Demand Forecasting
Authors: Wu Shan Shan , Han Xin Yang , Xue Wan Lei
Published: October 2014

In this paper, we firstly review the paper related to index system of economic society development, and divide and analyze the stage of Chinese economic development by using the theory of Chenery, Hoffman and Lewis. Then we selected indicators by using GRA and FA, and also consider the cointegration relationship of these indicators with power. Finally, we propose the index system of economic society development based on the medium and long-term electric power demand forecasting, which included 3 first-level indexes, 7 second-level indicators.
A Survey on Ownership of Home Appliances and Electric Energy Consumption Status According to the Number of Household Member
Authors: Won An Na , Hong Won Hwa
Published: October 2014

With increasing trend of nuclear family, modern society is also showing a gradual increase in single households. Increase in single household leads to increased use of home appliances. Accordingly, the aim of this study was to examine ownership of electric home appliances (home appliance products that use electricity) and energy consumption status and to obtain implications for energy conservation.A survey was conducted / analyzed on 2,250 households, and the following results were obtained. First, ratio of home appliance ownership and number of appliances per household member were examined. Average number of home appliances was 10.6 for single households, 13.8 for 2-person households and 17.5 for households with 6 persons or more. Second, electric rate was found to be 46,000 won for single households and 114,000 won for households with 6 persons or more. Electric rate per member of household was rapidly reduced from  to <4-person household>, showing about 50% conservation. In other words, increase in single households is regarded to have great impact on increase in energy consumption.
Research on Choice of Logistics Mode of B2C Enterprises with FAHP
Authors: Lv Yang , Sun Hong Sheng , Wang Xi Fu
Published: October 2014

Under the background of economic globalization and regional economic integration, B2C enterprises begin to focus on how to handle the relationship between logistics services and E-commerce services in the face of intense competition from other companies. This paper proposes a fuzzy analytical hierarchy process (FAHP) approach to select the logistics mode of B2C electronic commerce companies. In addition, a case study is presented to demonstrate how the approach can help in solving such problems in practice.
Energy Management and Coordinated Control Strategies of Isolated Micro-Grid with Wind Turbines and Seawater Desalination Devices
Authors: Fan Shi Tong , Liu Qing
Published: October 2014

The combined operation of large-scale off-grid wind turbines and energy-intensive seawater desalination devices will be one of the directions of the cleaner freshwater producing technology in the future. This paper discussed the operation modes and control strategies of isolated micro-grid with wind power, energy storage and seawater desalination equipments based on load characteristics of seawater desalination devices and operating characteristics of wind power, put forward energy management and coordinated control strategies to enhance the economical efficiency and stability of the system. Finally, a digital-analog simulation platform was build based on PXI+cRIO. The real-time simulations for various operating modes of this isolated micro-grid system verified the feasibility of the proposed strategies.
Kemskaya Wind Power Plant in Karelia
Authors: Sidorenko Gennady Ivanovich
Published: October 2014

The construction of large capacity Kemskaya wind power plant (WPP) at the coast of the White Sea was considered to decrease the deficiency of energy in the region. The results of wind energy resources research of the region are presented. The results of calculation of Kemskaya wind power plant parameters including net electricity production, hours of plant’s installed capacity utilization, and capacity factor are given. Three variants of Kemskaya WPP construction are considered: with capacity 30, 180 and 1000 MW.
Design and Development of Intelligent LED Plant Light Supplement System Based on Solar-Powered for Facility Agriculture
Authors: Wang Yi Wang , Zhang Bo , Kai Cao
Published: October 2014

Intelligent LED plant light supplement system can improve and enhance plant photosynthesis, increase crop yields, especially for anti-season greenhouse cultivation in the facility agriculture.For the application of greenhouse crop cultivation, design and development of intelligent LED plant lights system based on solar-powered, the system uses solar photovoltaic power supply to save the cost and environmental protection. And using the digital control technology to achieve intelligent LED plant light supplement system control. The hardware and software design of system were described in detail in the paper, the experimental tested prototype was completed.The designed system has the advantages of energy saving, digital smart, green and efficient, etc., which suitable for promote the application of modern facilities agriculture.
An MILP Formulation for the Thermal Unit Commitment Problem Considering Start-Up and Shut-Down Power Trajectories
Authors: Deng Jun , Wei Hua
Published: October 2014

This paper presents a mixed-integer linear formulation for the thermal unit commitment problem considering the start-up and shut-down power trajectories. A realistic and accurate modeling of the unit’s operating phase is given, which includes the phases of start-up, dispatchable and shut-down. The start-up type is decided by the unit’s prior off-line time. The start-up costs and power trajectories depend on the type of start-up. A new set of binary variables is introduced to represent the dispatchable status, which can decrease the binary variables and constraints significantly. Finally, a test case study is analyzed to verify the correctness and show the computational performance of the proposed formulation.
Pyrolysis of Hailar Lignite: Experiments with a Tubular Reactor and a Continuous Screw Kiln Reactor
Authors: Gao Hao Jie , Zhu Yue Zhao , Chen Hai Jun , Liao Chuan Hua , Du Yang , Wu Hao
Published: October 2014

Pyrolysis of Hailar lignite (moisture content ~ 34.81 wt%) was investigated at temperatures ranging from 700 °C to 900 °C in two different reactors: A tubular reactor (TR) and a continuous screw kiln reactor (CSKR). Under temperature programmed-heating conditions in the TR reactor, the auto-generated steam from the lignite moisture was vaporized and swept out of the reactor by the N2flow during the long heating process, leading to a weakened effect on the subsequent reactions. However, in the CSKR tests all the volatiles was generated continuously while avoid the carrier gas dilution , significant interactions between the in situ steam and the intermediate products occurred. Upon comparing the two pyrolysis processes, it was found the CSKR process exhibits higher H2yield of 23.23 mol/kg, H2proportion of 49.82 vol % than those (16.97 mol/kg, 41.51 vol %) from the TR process. The results demonstrated that inherent moisture in Hailar lignite had a significant influence on the product yield, depending on the pyrolysis conditions. It was also shown that increase in temperature led to rising dry gas yield and H2yield.
Simplified Least Squares - Support Vector Machines for Lead-Acid Batteries SOC Estimation
Authors: Zheng Li Chuan , Li Li Xue , Zheng Yi Hui , Wang Xin , Zhao Jian Ming , Chen Hong Tao
Published: October 2014

Lead-acid batteries are widely used in all walks of life, the State-of-Charge is the most important part of the battery management system. On account of the strong coupling, multivariable, nonlinear characteristics of the batteries, this paper adopts the LS-SVM method to predict remaining battery capacity. The nonlinear POLYnomial (POLY) kernel is employed to design the LS-SVM. Aiming at predigesting the hardware requirement of the LS-SVM application, this paper uses the deduced induction of the input vector to simplify the POLY kernel, greatly reducing the memory capacity of the practical application. At last, simulation on MATLAB was done to verify the validity of the proposed model, the simulation results show that the LS-SVM based on the simplified PLOY kernel is applicable to battery SOC estimation, and the estimation error can be controlled within 5%.
Research on the Effect of Movable Gel Flooding after Polymer Flooding
Authors: Liu Rong Wei
Published: October 2014

The experiments on microscopic displacement of flowing gel flooding after water and polymer flooding were carried out with the sand-packing model. The experimental results of the microscopic displacement indicate that oil recovery can be further enhanced using flowing gel after water and polymer flooding, and the enhanced range is about 15 percent. Flowing gel flows preferentially through the largerchannels occupied previously by injected water in flowing gel injection process, improves sweep efficiency of injected water. Because of its viscoelastic, it can be stretched through the narrow pore deformation. The strength was reduced by the shear, dilution, and it would be driven out by the water from the pores and continue to move forward. Therefore, the main function of flowing gel is flooding, while profile modification is temporary effect. Flowing gel flooding can significantly reduce the cost of chemicals. From the development of tertiary oil recovery trend, flowing gel flooding is a technology that is being developed and perfected, with high technology-economic feasibility.
Analysis of Trip Faults and Protection Measures on 10kV and 20kV Distribution Lines
Authors: Lu Yong Ling , Tao Feng Bo , Zhou Zhi Cheng , Gao Song , Chen Jie
Published: October 2014

Based on the trip faults data of 10kV and 20kV distribution lines which come from actually power grid in China, this paper has done a large number of statistical analyses and investigations. Trip faults are classified and analyzed by fault positions, monthly changes, fault causes and so on. Preliminary analysis suggests that main factors which lead to trip faults are outer forces, meteorological conditions, improper operation and maintenance, quality of equipment and design processes. Rains, strong winds and lightnings have the worst impact on distribution lines in a period from June to August. External forces caused the most faults on conductors, towers and stay wires. According to different failure reasons, countermeasures are put forward pointedly,so can provide references for improving power supply reliability in distribution network.
Research on Corrosion Diagnostic Model of Grounding Grid Based on Tellegen's Theorem
Authors: Wu Xin An , Li Li Xue , Zheng Yi Hui , Wang Xin , Cui De Min , Sun Jing
Published: October 2014

Grounding grid was considered as a pure-resistor network and its inner information was obtained through limited grounding leads. A set of diagnostic equations was established based on Tellegen’s theorem. Iteration method and Nonnegative Least Squares method (NNLS) were used to solve it. To verify this method, corrosion diagnosis of single-branch and two-branch was simulated. An optimal plan was proposed in the simulating calculation, which diagnosed step by step and added measurement nodes according to the result of each step. This method is able to determine the corrosion position and degree reliably and the optimal plan has higher efficiency and less workload.
The Whole Simulation Analysis and Measurement of the Power Frequency Electric Field in 500kV Substation
Authors: Peng Luo , Ming Li Yong
Published: October 2014

An improved Charge Simulation Method (CSM) is proposed in this paper. Based on this method, the model of the overall 500kV substation is established, and then the power frequency electric field in substation at the height of the 1.5mabovethegroundis simulated and calculated. Specifically, these on 500kV switch yard in the station are simulated and analysis. The results show that the simulation results are in good agreement with the actual substation measured results, which is proved the correctness of the model and the algorithm. This paper provides an effective method for the rapid analysis of the distribution of power frequency electric field in ultra-high-voltage substation, and also can use the method to study the effects of electric field distribution factors in substation.
Effect of Substation Network on Transformer PD Monitoring
Authors: Man Yu Yan , Zhang Chi , Wang Nan , Zhang Li Ming , Wang Hao Ming
Published: October 2014

In this paper, a simulation model for the propagation of transformer PD pulse has been constructed,and the propagation of PD in a real substation were investigated. We also studied the frequency characteristics of currents at different detection positions, and the influences of substation network are analyzed in aspects of system resonant frequency. The optimal detection position and the optimal measuring band are proposed. The results show that, the calculated range of substation network and capacitive apparatus play the key roles in impedance characteristics.
Analysis and Countermeasures of Value Side Bushing Fault of Converter Transformer in Gezhouba to Nanqiao HVDC Transmission Project
Authors: Huang Yue Hua , Hu Li Hua , Li Jia Wei , Xia Hai Fan
Published: October 2014

Converter transformer is one of the most important equipments of UHVDC power transmission system, its faults directly affects the safe and stable operation of DC system. The valve winding of converter transformer needs to withstand the voltage that consist of DC voltage and serious distortion of AC voltages (harmonic bound) which are similar to the AC sine waveform compound voltage, so in the design and manufacture of the valve side of converter transformer, bushing is much more complex and difficult than alternating current casing.Valve bushing is weak spot of converter transformer insulation. Through the anatomy of failure bushing, the reason of bushing failure is analyzed. Without changing body size of the converter transformer, the bushing of new structure is developed and the old bushing is replaced to improve the reliability of equipment operation.
Design for the Controller of Desktop 3D Printer
Authors: Huang Ruo Dong , Wang Xin , Zheng Yi Hui , Li Li Xue , Sheng Xi Kui , Wu Hao
Published: October 2014

3D printing, is a kind of rapid prototyping manufacturing, fabricating expected objects by way of cumulative constructed layer by layer, based on digital model files and powdered materials used. In this paper, the controller of desktop 3D printer is designed and carried out, both from the hardware and software part. For hardware design, a 32-bit ARM core microcontroller, STM32F103VB is selected as the core, supplemented by stepper motor driver chips, thermocouple digital converters and other devices, which build a desktop 3D printer controller panel. For software design, referred to open-source design being based on the AVR microcontroller, the whole process of 3D printing is accomplished by programming the ARM core microcontroller.
Study on Loss Calculation for Inverter Based on 1200V SiC MOSFET
Authors: Xie Li Jun , Li Jin Yuan , Yu Kun Shan
Published: October 2014

SiC MOSFETs are expected as one of next generation power devices for their superior performances compared with conventional Si power devices and have become one of the new promising substitude to Si devices. The characteristics of 1200V SiC MOSFET are presented first and the power losses analysis model of SiC devices are given. As losses of power devices are essential parameters in converter design, the power dissipation of SiC MOSFET in SPWM inverter are calculated. In this paper, whether a free-wheeling-diode necessary is illustrated from the point of power dissipation and choice is made based on the power loss. According to the analysis result, the inverter without SBD shows less power losses, which can reduce the cost and volume of inverter.
Study on Power Supply of the Feeder Terminal Equipment
Authors: Hu Han Mei , Shi Ya Jing , Zhang Yan Hua , Fu Ya Ling
Published: October 2014

Converter transformer is one of the most important equipments of UHVDC power transmission system, its faults directly affects the safe and stable operation of DC system. The valve winding of converter transformer needs to withstand the voltage that consist of DC voltage and serious distortion of AC voltages (harmonic bound) which are similar to the AC sine waveform compound voltage, so in the design and manufacture of the valve side of converter transformer, bushing is much more complex and difficult than alternating current casing. Valve bushing is weak spot of converter transformer insulation. Through the anatomy of failure bushing, the reason of bushing failure is analyzed. Without changing body size of the converter transformer, the bushing of new structure is developed and the old bushing is replaced to improve the reliability of equipment operation.
Reliability Analysis of Distribution Network with Integrated Photovoltaic Power Generation
Authors: Huang Ke , Wang Xin , Zheng Yi Hui , Li Li Xue , Liu Yan Ling
Published: October 2014

To analyze the influence of distribution network with grid-connected photovoltaic (PV) generation on the power supply reliability, in this paper it firstly regards interconnected PV generation as an equivalent generator with rated capacity as well as the island operation mode of PV to set up a model for reliability calculation and analysis. Based on the network equivalent method, the structure of distribution system with PV is simplified and then the reliability indexes of distribution system are worked out based on Failure Mode and Effects Analysis (FMEA). At last, a comparative calculation between the distribution network with incorporated PV generations and that without PV generations is made. After analyzing a real example, the results suggest that integrating PV power generations reasonably into the distribution network can enhance the reliability of whole distribution system.
Phytoremediation on PAHs in Soils and Laboratorial Technics
Authors: Lei Zhi Hua , Wu Yun Xiao
Published: October 2014

Potentials of three plant species, rape, alfalfa and white clover, separately or jointly on the degradation of polycyclic aromatic hydrocarbons (PAHs) in soil were estimated by pots experiments. Results showed the presence of vegetation apparently enhanced the dissipation of PAHs at initial concentrations ranging from 20.05 to 322.06 mg·kg-1. Within 70-day experiment, alfalfa and white clover showed higher efficiencies for removal of PAHs than those of rape, and mixed cropping greatly enhanced the dissipation of PAHs as compared to single cropping. On average 74.87% of phenanthrene or 62.81% of pyrene were removed from soils with mixed cropping of rape and alfalfa, and 72.01% of phenanthren or 68.44% of pyrene removed by mixed cropping of rape and white clover. Results suggested a feasibility of the establishment of multispecies remediation for enforcing the dissipation of PAHs.