bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on Thermal Environment of Direct Gain Solar and Heating Rooms
Authors: Chen Lin Bo , Liu Jia Ping , Zhang Wei Hua
Published: March 2013

The indoor thermal environment usually is measured in the condition of heating or cooling. This paper studies the thermal environment in direct gain solar and heating rooms. The indoor and outdoor temperature and relative humidity, inner surface temperature, human action, and times of opening door per day, are field tested and analyzed. PMV index is used to evaluate thermal environment. The results show that the relative humidity in direct gain solar and heating rooms is too low to comfortable. The curtain from closed to open, the window inner surface temperature decreases 13.9 °C in north orientation room, and decrease 10.3 °C in south orientation room. The indoor air temperature, relative humidity and inner surface temperature at the height of 1.5 m change a little by normal opening door. Thermal environment evaluation proves that in cloudy day, north orientation room is more comfortable than the south orientation room, while in sunny day, their difference of thermal sensation decreases. So we suggest that in order to keep thermal comfort, the curtain should be closed on the condition of no solar energy, the relative humidity should be designed during heating design, and the facing correction factors should be revised, so that the south orientation room is comfort in cloudy day. For energy conservation, the north exterior window should be smaller than the south exterior window.
The Study on the Calculation Method of Energy Savings of Heating System in China
Authors: Liu Yi Min , Yu Dan
Published: March 2013

This paper mainly describes energy savings calculation methods of system. The method of heating degree day method for quantifying energy savings is presented. Combined with some actual projects, the application of some energy savings calculation methods was discussed and analyzed. The method of heating degree day found to be an efficient method of calculating energy savings on heating system. The heating heating degree day method can be set up rapidly and is useful for energy saving measurements.
An Economic Analysis of a New and Renewable Energy System Installed at a Public Building
Authors: Kim Gwang Hee , Won Dong Min , Kim Kyong Gon , Shin Yoon Seok
Published: March 2013

Recently, Korean government has made an effort to promote the use of a new and renewable energy system institutionally. However, in order to succeed in that promotion, it is preferentially necessary to perform a analysis of the effects of utilizing the system. Therefore, the objective of this study is to analyze the economical feasibility of the new and renewable energy system installed at a public building. As a result of a case study, this system showed the economical feasibility in operation cost and payback period.
Experimental Research on the Heat Transfer and Mechanical Property of Phase Change Material Wallboards
Authors: Yan Quan Ying , Huo Ran , Yue Li Hang , Zhang Lin , Jin Li Li
Published: March 2013

This paper investigated the heat transfer and mechanical property of phase change material (PCM) walls and common wall. Three mixtures of liquid paraffin-46# paraffin, liquid paraffin- lauric acid and capric-myristic acid were prepared and mixed respectively with high-density polyethylene (HDPE) to prepare shape-stabilized phase change materials. Then direct mixing method was used to add these materials into cement mortar in order to make phase change walls. The results shows that the temperatures and heat flow on phase change walls’ surface are all lower than those of common wall; PCMs of different thermal properties have a more and more obvious distinction in heat storage performance with the increasing content of them added in the wall; PCM walls have lower compressive strength than the common one. Results can provide the basis for the application of phase change material walls in real buildings.
Shrinkage of New Concrete Restrained by Old Concrete Based on Interface Roughness
Authors: Wang Zong Li , Li Guo Dong
Published: March 2013

Based on the analysis of the early shrinkage mechanism of concrete, shrinkage experiment of new concrete restrained by old concrete were conducted to analyze the impact of the different interface roughness on shrinkage stress of new concrete and bonding surface. It is shown that the inner tensile stress of new concrete decreases with increasing of interface roughness, and increase restrained thickness of the new concrete, but it is not significant effect of interface roughness on the shrinkage at bonding surface; the shrinkage strain of section reduces with reduction of the distance of section to bonding surface and reaches minimum on bonding surface, which reflecte significant nonuniformity and increases gradually with age.
The Research and Implementation of Beijing Energy Policy Simulation System
Authors: Han Yan Min , Shen Xiao Liu , Guo Jun Hong
Published: March 2013

Energy is the power sources of economic growth. But, its consumption can also cause the environmental pollution. In this paper, we introduce Beijing Energy policy Simulation System, which is a simulate software to help researchers with studying energy, economy and environment. This system collects historical data throughout the years, and its applications mainly contain Energy Index Data Acquisition Subsystem (EIDAS), Energy Index Comparison Analysis Subsystem (EICAS), Energy Factor Analysis Subsystem (EFAS) and Energy Control Simulation Subsystem (ECSS). This paper displays the index system of Beijing Energy policy Simulation System, which is the precondition and foundation of the research. The main purpose of this paper is to introduce Feedback control thought into Energy policy Simulation System.
Study on City Energy Plan and Control
Authors: Yong Qi Dong , Chen Yang , Li Jun
Published: March 2013

In the article, the CD city energy consume is taken as the study object, the formula of energy consume amount forecast is deduced by the method of coefficient of elasticity, energy control model is put forward, the growth amount of the GDP and the energy consume amount of the CD city are forecasted based on the model, and then the energy control object is brought out. Through the forecast model and control model of the CD city energy consume, the energy consume structure of the CD city will be optimized during "twelve five-year" period, unit GDP energy consume amount will be decreased, and the energy consume control of the CD city will be realized efficiently. Finally, the counter measures and advices are submited by the forecast result from the model before.
Study on Performance Evaluation System of R&D Team of New Energy Enterprises
Authors: Du Li Fu , Wu Jian Long
Published: March 2013

The R&D team supports sustainable competitive advantage of new energy enterprises, and performance evaluation is the key point of the team management. Using the balanced scorecard theory, the paper designs R&D team performance evaluation index, around finance, customer, learning and growth and internal operations of four dimensions. Then, the paper builds index weights method and comprehensive evaluation model based on AHP and fuzzy evaluation principle, taking GY group as an example. This research is to provide methodological support for R&D team management of new energy.
Analysis of Energy Efficiency in China with a Slack-Based Directional Distance Function Approach
Authors: Liu Rui Xiang , Luo Jing
Published: March 2013

It is crucial to improve China’s energy efficiency in the context of energy conversation and environmental regulation. This paper approaches the measurement of Chinese regional energy efficiency based on slack-based directional distance function from a production theoretic perspective. The results show that there exists inequality among different regions in China and the east area have the best average energy efficiency for the period 2000-2009, followed by the central area. Based on these findings, this paper correspondingly proposes some policies to improve energy efficiency in China.
Decomposition of Overall Specific Energy Consumption over 1990-2010 in China’s Cement Industry
Authors: Ge Hai Meng , Mu Hai Lin , Cong Xi Long , Li Hua Nan
Published: March 2013

This paper presents a complete decomposition analysis of overall SEC (specific energy consumption) in China’s cement industry for the period 1990-2010 divided into four equal time intervals. The complete decomposition method developed by Sun is used to analyze the nature of three factors: clinker share, process structure and kiln efficiency. However, to consider the overall specific energy consumption, we also consider the impact of ancillary process. The results show that all of the four factors drive overall SEC down in the entire period, while only the factor of clinker share drive overall SEC up during the period 1995-2000. Moreover, based on the analysis of decomposition results, the technological improvement and structural adjustment would result in major potential for the reduction of overall SEC in the future.
Preliminary Research on Energy Consumption in Machinery Manufacturing Industry in China Based on Input-Output Analysis Method
Authors: Guo Xiao Qiao , Zhang Bin , Yan Gang
Published: March 2013

As china become the world factory, machinery manufacturing industry accounts for more and more part of economic development and energy consumption in china nowadays. Based on input-output analysis method, the direct and complete coefficients of energy consumption in machinery manufacturing industry were calculated, and the percentage of energy consumption driven by different factors was also computed respectively. It can be demonstrated machinery manufacturing industry will induce the energy consumption in the other industries extensively and exporting is the main factor which drives the energy consumption in machinery manufacturing industry.
Research of Residents Cognitive and Attitude towards Renewable Energy
Authors: Huang Yin Tsuo
Published: March 2013

Recent years, the price rise of energy resource , the climate change caused by the abuse of fossil fuels, the Tokyo Protocols which limited the ejection of greenhouse gas and many other things have caused unprecedented huge impact and threat. Taiwan , which relies 98% on importing energy sources, has very little local energy source , very low reservation of petrol and very small proportion of self-running coal and gas facilities, therefore the energy security condition has become quite severe. This essay mainly discusses the cognition and attitude of community residents towards renewable energy in Taiwan, analyzes people’s different cognition and attitude, elaborates the correlation between cognition and attitude towards renewable energy and in the end offer some suggestions to the related professionals and researchers.
A Study on the Decoupling between Economic Growth and Carbon Dioxide: A Case on the Shanxi Province
Authors: Qing Dong Rui , Sun Yao Hua
Published: March 2013

The paper introduce and handle OECD decoupling model based on DPSIR framework(the driving force-pressure-state-impact-response).Through the model recommended by IPCC, calculate the emissions of carbon dioxide of industrial department in Shanxi province during the period of 2000-2007.Analysing the situation of decoupling among GDP of Shanxi, the energy consumption of Shanxi industrial and carbon dioxide emissions with OECD decoupling model.The conclusion shows that the industry in Shanxi has exhibited outspread link among GDP,energy consumption and carbon dioxide emissions, and also this paper analyse the reasons of this situation.
The Devolopment of Eco-Tourism with Convergence Theory
Authors: Ji Pei Ling
Published: March 2013

Baumol proposed the empirical research on convergence of economy growth in 1986, and then a lot of related research came out. These Macro-economic theories enlighten us on regional research of eco-agricultural tourism in China, and lead a new thinking for quantitative research of tourism management. Eco-agricultural tourism, as one of the kinds of “back to nature”, becomes more and more popular. There are two means to apply theories said above to research on eco-agricultural tourism: one is Income return of eco-agricultural tourism based on cross section data (including panel data), the other one is analysis based on time series data.
The Institutional Guarantee of Eco-Tourism Resources Value Compensation Mechanism
Authors: Wei Min , Chi Feng Lian
Published: March 2013

With the rapid development of china's economy, the conflict among economic construction and ecological environment is also increasingly prominent. People gradually realize the importance of the social, economic and ecological environment harmonious development during the pursuit of economic growth. The value compensation mechanism of ecological resource is a kind of compensation system to adjust the stakeholders, to protect relations between environmental benefits and economic benefits distribution activities and to improve, maintenance and recovery of ecological resources value system. In order to build a perfect powerful compensation mechanism and become a real ecological resources' protection power mechanism, incentive mechanism and coordination mechanism, it need through a series of system and perfect security system to achieve, so as to ensure the implementation of compensation.
Analysis on China's Energy Low Carbonization under the Background of Industrialization
Authors: Wang Feng Yun
Published: March 2013

As a developing country with a large population, China is in the high energy consumption stage of industries development at present. Therefore, the primary issue that we confront is to establish the sustainable energy supply system and economic development pattern. According to the characteristic of energy consumption under the background of industrialization, the paper studies the situation of low carbonization energy consumption development and analyzes its existing problems from the industrial structure, the energy structure and energy efficiency, etc. in China. Finally, the paper puts forward the corresponding countermeasures and suggestions.
Bottleneck at Promoting Strengths of Tourism-Culture Integration in Ancient Town Cicheng and Enlightenments for Development
Authors: Yan Guo Dong , Kang Jian Cheng , Wang Guo Dong , Han Qin Chen
Published: March 2013

Integration of cultural content and tourism in an ancient town is of great significance for promoting inheritance and protection of Chinese cultural relics, enhance China’s soft power, and facilitate harmonious development of the society. Cicheng has got somehow achieved, but compared with the top 6 ancient towns in Southern China, the function of historic heritages and cultural deposits to drive tourism development hasn’t been fully exerted. Thus, analysis the characteristics of tourist and cultural resources, Advantage and bottleneck at combined development of tourism and culture so as to promote regional economic structure transformation and harmonious development of society.
Optimization Research on Carbon Emissions and Energy Structure of Responding to Climate Change
Authors: Song Mei , Lin Zong Yuan , Zuo Yan Qing , Chen Tao
Published: March 2013

The convening of Copenhagen Climate Conference marks that carbon emission accepted as a hard constraint in most countries. This paper first reviewed the development course of the carbon emission study; Secondly, the paper forecasts the energy demand and carbon intensity before 2020 of China by the method of the elasticity coefficient; As China's current energy consumption structure cannot reach the 2020carbon reduction target, we optimized China's energy structure, proposing the measures of "speeding up the transformation of economic growth mode, promoting the energy saving of the whole society, accelerating the exploitation of non-fossil energy and developing the coal orderly " accordingly.
Research on the Sustainable Development Based on PREES Model of Beijing
Authors: Guo Wen Yan , Ma Li , Wang Qiong , Shen Xiao Liu
Published: March 2013

This paper studies the coordinated development of Beijing's population, resources, environment, economic and society. With the rapid development of the city, Beijing’s population, society and economic is getting more and more contradictive against its resources and environment, under which circumstance a scientific study on the coordinated development is urgently required. This essay is based on the data of last 10 years of Beijing, and formulates a PREES model of the PREES model in Beijing. This study uses the method of principal component analysis via SPSS, establishes the coordination degree evaluation system of Beijing’s population, resources, environment, economic and society, and runs an empirical analysis afterward. This essay calculates the coordination degree of Beijing’s population, resources, environment, economic and society, analyzes and studies the main issues in Beijing’s coordinated development, and gives relative suggestions.
A Testing Facility for Refrigerating Plants Equipment Working with New Fluids
Authors: La Rocca Vincenzo , Messineo Antonio , Morale Massimo , Panno Domenico
Published: March 2013

A test rig was built in the department of energy, in laboratory of refrigerating engineering for test runs with a lot of fluid and equipment of various kind for commercial refrigeration. The facility has been continuously improved during the past years and allows to perform experiments aiming to assess the performance characteristics both of conventional and new equipment for commercial refrigeration. In the test rig can be tested a lot of cooling loop filled with a secondary fluid for simulation of their behavior in industrial and commercial plants (e.g.: during exploitation in supermarket and hypermarket for refrigeration of foodstuffs in cold store, display cases and cabinets, etc.). The paper reports main results of the experiments performed with the new fluid R422A versus the original refrigerating fluid R22.
Discuss on Post Combustion Characteristics of the 116MW Circulating Fluidized Bed Hot Water Boiler
Authors: Qi Guo Li , Guan Jian , Leng Hao
Published: March 2013

116MW circulating fluidized bed hot water boiler performance testing was carried out that found that burning high volatile lignite had post combustion phenomenon of separator yet. The phenomenon of post-combustion research results show that flue gas outlet temperature rise of the separation can be significantly reduced by adjusting the twelve wind ratio; Increasing coal-fired granularity which was able to reduce the separator post combustion phenomenon; Moderate post combustion of separation was able to improve boiler efficiency and reduce N2O. These results can provide guidance for improving boiler operation technology and improving the boiler design standard.
The Experimental Investigation on the Internal Temperature Field of Regenerative Burners
Authors: Tian Zhong Jun , Jin Shi Ping , Liang Yu Ming , Tian Kui , Hao Zhen Biao , Luo Xue Jiao
Published: March 2013

The application of regenerative combustion technology to industry burners has been a huge success. This paper presents an experimental study on the change of the temperature field and the concentration of NO in the flue gas in an industrial furnace. The result showed that the concentration of NO increased with the rise of temperature. For the reversing time of 20s, 40s, 60s, and 80s, the temperature of each point changed in accordance with similar rules, but the temperature of the former three measuring points did not obviously change. The heat transfer occured mainly in the last two layers of the regenerative cells, and the utilization of all the regenerators was only 40 percent. The heating curve of the sixth measuring points was significantly different from the cooling one. With the increase of the reversing time, the flue gas and the air temperature variation also increased.
The Air Conditioning System of a Large Public Building Energy Consumption Simulation Research
Authors: Jing You Yin , Li Ting , Liu Qian Qian
Published: March 2013

The large building air conditoning system with different modes were made , which include the constant air volume system, variable air volume system, the temperature and humidity independent control system. To calculate energy saving rate, the energy consumption simulated by DeST energy simulation software.
Humidity Distribution Simulation of Passenger Vehicle Cabin
Authors: Xiang Li Ping
Published: March 2013

A numerical model to improve the air-conditioning system of vehicle cabin taking into the cabin air moisture and its transport by the airflow within the enclosure cabin is described. An efficient computational fluid dynamics(CFD) technique is using the “realisable” model. The temperature and humidity fields in the passenger cabin are investigated individually under having or no body moisture. The temperature in the vehicle cabin taking into account human moisture is lower than no taking into account moisture 0.5 °C. The human dispersing moisture effect significantly on the humidity, which lead to the humidity is elevating and the humidity in vehicle cabin is corresponded hygienic standard.
A New Type of Solving Method for Reliability Model Parameter Optimization
Authors: Zhou Zhen , Zhou Li Li , Ren Ye , Ma De Zhong , Fan Shang Chun
Published: March 2013

Most of solving method for reliability growth model parameters is to structure maximum likelihood function and extremum on the likelihood function. When the maximum likelihood method is adopted for the evaluation and optimization of parameter, because of the effect of iterative initial value, the classical one is not easy to converge to the global optimal solution. Evolutionary programming (EP) algorithm used in this paper , its feature is to establish the fitness function, find great value point to determine optimization model of the parameters optimal solution, and it is not necessary to find extreme value and estimate initial value of the optimization variable to obtain global approximate optimal solution. In order to better ensure global optimal solution, to further ensure the accuracy of the equations, a parallel operation and retain the best individual and other methods are used in evolutionary programming algorithm. The new method for solving the optimization parameters can achieve a better balance in the solving efficiency and convergence performance and better combined optimization methods with maximum likelihood estimation method. The validity and correctness of the optimization method is verified in the last of the paper through the experimental data in the reliability growth process of a solid rocket motor.
A Study of Bio-Diesel Application on 6L20(27) Diesel Engine
Authors: Cao Hai Quan , Xue Yun , Lu Xue Cheng
Published: March 2013

Biomass alternative fuels have been around the world attention. This paper studies the characteristics of bio-diesel, bio-diesel by analyzing the physical, chemical properties, comparative bio-diesel and military advantages and disadvantages of diesel fuel come to bio-diesel is a diesel engine available in alternative fuels. In order to verify the heavy-duty off-road vehicles and light army vessel used biodiesel economy, power and reliability, we use the MAN-B & W6L20(27) diesel engine on the practical application of bio-diesel experiment results showed that: the security, power, oil consumption, emissions and reliability of all the available fuel to reach the target, it can be used as a safe alternative fuel use in diesel engines.
Pressure Drop in Horizontal Taper Pipe of Dense-Phase Pneumatic Conveying
Authors: Duan Guang Bin , Wang Kun , Liu Zong Ming
Published: March 2013

Experimental research was performed to describe the pressure drop occurring in horizontal taper pipe of dense phase pneumatic conveying, which were widely used in the engineering project. Compressed air was used as transmission power and fly ash as the transport medium. Results showed that the geometric parameters of taper pipe including taper angle and diameter ratio had a dominant effect on the pressure drop of the gas solid flow. In addition, a three-dimensional numerical simulation was performed to show the trend of the pressure field intuitively in the transporting process. And the simulation results of pressure drop were validated by the experimental data.
Study on the Flow Characteristics of Transverse Injection in Cavity
Authors: Sun Hai Jun , Zeng Zhuo Xiong , Xu Yi Hua
Published: March 2013

The combination of transverse injection and cavity flame stabilizer is a good way to improve the mixing efficiency and flame stability. In order to study the influence of transverse injection on the flow field of cavity in advanced vortex combustor, the turbulence flow and the fuel distribution under the influence of different assignments of jet holes were simulated numerically. The results show that the different assignments of jet holes have a bigger impact on the geometry and center of vortex, but lesser on the total pressure of combustor. The content of fuel reduces quickly in the jet direction, injection can improve the mixing of fuel and air. The phenomenon of mass diffusion and transport is obvious, it is in favor of flame stability.
Analysis of Optimal Configuration of Building Integrated Photovoltaic (BIPV) Array under Moving Partial Shade
Authors: Qi Jun , Wang Jing , Liang Xiao Li
Published: March 2013

Influenced by partial shade, there are power losses induced by irradiation reduction, photovoltaic (PV) modules mismatch and maximum power point tracking (MPPT) failure. In order to raise power generation efficiency of building integrated PV (BIPV) power station, typical series-parallel PV array controlled with centralized MPPT is taken into consideration. Simulation model is constructed to describe the output characteristic of PV array under complex partial shade conditions. Due to bypass/blocking diodes, there are multiple peaks on P-V characteristic curve under partial shade. Potential power losses under partial shade are analyzed and divided into three parts respectively. Simulation results demonstrate that there are considerable power losses induced by PV module mismatch under determined tangible partial shade lasting for long time. Optimal configuration of BIPV array are brought forward to minimize PV module mismatch power loss for moving shade conditions, and it is also suitable to large desert or hillside PV power stations.
Working Condition Diagnostics System for Electrical Submersible Pump in Geothermal Well
Authors: Wei Ya Zhen , Wang Feng Qing , Wu Guo Dong , Chen Lei , Liu Li Feng , Dong Jia Shan , Li Zhen Long
Published: March 2013

The situation of the global energy is tending to be in short supply, but geotherm is the inexhaustible renewable energy. Extracting reservoir geothermal water from old oil well can achieve economic benefits of oil - heat joint production. Since 2005, Huabei oilfield has been engaging in geothermal comprehensive utilization research projects and developed the large displacement electrical submersible pumps suitable for high temperature. For the operation management of this equipment, the working condition diagnosis analysis research has been carried out, 16 kinds of current curve template and 73 kinds of pump characteristic curve template have been established using ADO remote data access technology, and the volume efficiency and energy efficiency dynamic control model and chart have been established as well. The production situation analysis using the chart can timely find out the problems existing in the production and puts forward the improvement measures to achieve the purpose of energy saving and consumption reduction.
Molecular Dynamics Simulations of Thermal Transport at the Nanoscale Solid-Liquid Interface
Authors: Kou Zhi Hai , Bai Min Li , Zhao Guo Chang
Published: March 2013

Simulation of nanoscale thermo-fluidic transport has attracted considerable attention in recent years owing to rapid advances in nanoscience and nanotechnology. The three- dimensional molecular dynamics simulations are performed for the system of a liquid layer between two parallel solid walls at different wall temperatures. The solid-solid interaction is modeled by the embedded atom method. The heat flux through the solid-liquid interface is calculated by Green-Kubo method. The effects of interface wettability and wall temperature on the interfacial thermal resistance are also analyzed. It is found that there exist the relatively immobile quasi-crystalline interfacial layers close to each solid wall surface with higher number density and thus higher local thermal conductivity than the corresponding liquid phase. The interfacial thermal resistance length is overestimated by 8.72% to 19.05% for the solid-solid interaction modeled by the Lennard-Jones potential, and underestimated based on heat fluxes calculated by Fourier equation.
DSP - Based Islanding Protection for Photovoltaic Grid Connected Inverter
Authors: Tunlasakun Khanchai
Published: March 2013

This research presents the DSP - based islanding protection for photovoltaic grid connected inverter with under / over frequency and under / over voltage islanding protection methods. The design is based on the TMS320VC33PGE digital signal processor on the NI SPEEDY 33 board from National Instrument Inc. The prototype is monitor the grid frequency and grid voltage at the point of common coupling (PCC) between the photovoltaic grid connected inverter, the local load and the distribution. The results of study, the prototype can turn off relay between photovoltaic grid connected inverter and utility grid when the frequency is change under 48Hz or over 52Hz and the voltage is change under 200V or over 240V.
Economic Operation Assessment of Micro-Grid Combining Photovoltaic and Energy-Storage
Authors: Wei Li Fang , Zhang Min
Published: March 2013

In order to carry an economic analysis of micro-grid project represented by photovoltaic power-generation, this paper proposed a cost recovery model for micro-grid project through case studies. Meanwhile, based on how micro-grid participates in market competition, we have designed the framework for gaining profits. Issues like basic profits, reasonable depreciation method and the project’s financial profitability are analyzed in detail.
New Development in Relay Protection for Smart Grid – Protection Function Development
Authors: Ding Pei , Guo Fei , Wu Xu Tao , Li Xiu Guang , Yan Zhen Hua , Hao Zhi Guo
Published: March 2013

The requirement is that the protection relay provides early warning for the protected device in order to guarantee the system reliability and high system security after fault is cleared. The development of new protection functions for smart grid is introduced in this paper. The principles and techniques of integrated state monitoring and main protection techniques for transformers are presented. The principles and techniques of transmission cross section protection which has developed from the line overload protection technique is also presented to show its application to avoid cascading overload tripping. Finally an islanding control system is presented. In the control system the islanding center is responsible for the co-ordination, and optimization and out-of-step relays are responsible for complimentary action. The aim of islanding control is that load-generation imbalance in each island is minimized and generators in each island are not out of step any more.
Assessment of State of Urban Power Supply Systems’ Power Transmission Lines on the Basis of Indicative Analysis
Authors: Dmitriev Stepan A. , Kokin Sergey E. , Khalyasmaa Alexandra I.
Published: March 2013

The article deals with the problem of the optimal development of urban power supply systems. The article offers various methodological approaches to discovering weak points of the existing power networks, as well as most effective ways of pinpoint actions in the situation of shortage of information and funding.
Research on Method for Obtaining Time Difference of Localization of Transformer PD Source
Authors: Xie Hong Ling , Shen Bo Yi , Wang Fei Long , Li Yan Qing
Published: March 2013

Ultrasonic positioning accuracy of transformer partial discharge is not high. The main reason is that it is difficult to obtain accurate time difference of the ultrasonic signals reaching two different sensors, especially when the signal-to-noise ratio is not high enough. To solve this problem, Hilbert-Huang transform (HHT) is applied in signal processing to extract the precise moment, and in this way the precise time difference is easily obtained. The signal-to-noise ratio (SNR) of received signal is low, and even worse PD signal is drowned in the strong interference signal. For this, the method named fast independent component analysis (FastICA) is applied in ultrasonic signal denoising before obtaining the time difference. FastICA is not effective in separating the ultrasonic signal from the separated components and in order to solve the problem, envelope identification method is proposed in this paper. In the method, the upper envelope of the signal waveform is sampled and the average of the sampling points is calculated to extract the ultrasonic signal. The numerical result confirmed the practicality of all the mentioned methods.
Series Reactance Rate Design of Shunt Capacitor with the Current-Limiting Reactor in Consideration Based on Particle Swarm Algorithm
Authors: Fan Cai Jie , Li Qiong Lin , Liu Shu Ming , Xu Yong Hai , Wang Shuo
Published: March 2013

Combined with the actual situation of transformer substation, PSO model is built to optimize the shunt capacitor series reactance rate in this paper. First, system harmonic impedance is analyzed and the harmonic impedance model is built. Second, the objective function and constraints of the optimization algorithm were set. The goal is to make the current distortion rate of high side smallest under the condition of the capacitor banks working safely, the output results will be the optimal allocation of the series reactance rate. Current-limiting reactor was also considered the influence to the design of series reactance rate. At last, testify the effectiveness with comparing the effect to the traditional way of designing the series reactance rate and prove the significant influence of the current-limiting reactor.
A Single-Ended Transient Based Voltage Protection Method of UHVDC Transmission Line which Distinguishes the Opposite Side’s Internal and External Fault with Protectors
Authors: Chen Shi Long , Zhang Jie , Xie Jia Wei , Liu Li
Published: March 2013

The paper studied the frequency characteristics of UHVDC transmission line and UHVDC transmission line boundary and their attenuation to high frequency components of fault-generated transient signal. The paper points out that existing approaches which utilize protectors to distinguish local side’s internal or external fault can’t protect the whole line. UHVDC transmission line and UHVDC transmission line boundary’s attenuation to high frequency fault-generated transient signal is overall considered, and a single-ended transient based voltage protection method which distinguishes the opposite side’s internal and external fault is proposed. The Yunnan-Guangdong UHVDC model of actual parameters was built up by PSCAD, and simulation experiment was conducted.
Research about Voltage Support of Distribution Network with Distributed Generation
Authors: Sun Ying Ying
Published: March 2013

It brings all kinds of negative and positive impact on distribution network with the distributed generation connection. Feeder voltage of the distribution network will be affected. Distributed generation can play a good supporting role to the feeder voltage, which also can make feeder voltage exceed the maximum safe voltage. The details have an important relationship with the capacity, size and location of distributed generation. The voltage supporting model and voltage calculation method of distributed generation connected with distributed network is given in the paper. The IEEE 34 Node model was chosen to be discussed how different factors can influence the feeder voltage. This paper analyzes distributed generation’s influence to the distribution system voltage level.
Modeling and Simulation of the Automatic Transmission Assembly Using Matlab/Simulink
Authors: Zhao Shuai , Guo Rui , Xu Liang , Guo Xue Li
Published: March 2013

This paper concentrates on modeling and simulation of the automatic transmission assembly using Matlab/Simulink. The entire simulink model includes four major models. They are the torque convertor and its lockup clutch model, the automatic transmission gearbox model, the equivalent spring model and the logical model respectively. After building the model, a comparison between this Simulink model and Carsim software is provided and the result curves matches very well, which proves that the Simulink model is accurate.
Screening of Microorganisms Capable of Producing Ethanol by Direct Fermentation of D-Xylose
Authors: Lu Zhi Tang , Lin Sheng Xun , Zhang Da Wei , Dong Huan
Published: March 2013

A total of 120 D-xylose fermenting yeast strains were isolated from composition soil samples. 6 strains capable of fermenting D-xylose to produce ethanol were obtained by TTC double medium agar method screening and potassium dichromate oxidation method re-screening. All the 6 strains belong to the genera Candida or Pichia by morphology and physiology identification. Candida spp. strains showed rather high efficiency to produce ethanol from D-xylose than the Pichia spp. strains, of which, strain M-105 exhibited a D-xylose consumption rate of 98.28% and the highest ethanol yield (0.465 g/g), with concentration up to 18.58 g/L under the condition of fermenting 40 g/L of this sugar at 28°C and 100 r/min for 72 hours. An average ethanol concentration of 18.35±0.07 g/L was reached from three batches fermentation of M-105 in shaking flask.
An Active Power Filter Controller Based on Dual-DSPs in Low-Voltage Power System
Authors: Zou Wan Feng , Zhang Lei
Published: March 2013

To compensate harmonics from nonlinear load, the controller of Active Power Filter (APF) need to detect harmonic and generate compensation current in high speed. APF controller functions are divided into two parts: outside controller part and inside controller part. Inside controller part detect harmonic current and control the IGBT to generate grid harmonics current. Outside controller part detect common power parameters and generate signal of management in main circuit. An experiment circuit of APF Controller is established. Some experiments are presented here.
Compensation of Phase Modulation Disturbance in All Fiber-Optical Current Transformer
Authors: Luo Yun Han , Xia Li Jia , Liang Cheng , Yu Jian Hui , Zhang Jun , Chen Zhe
Published: March 2013

In order to improve measurement accuracy of all fiber-optical current transformer (FOCT), an improved demodulation algorithm was proposed for a sine modulation. The formula for effective phase modulation depth (EPMD) was firstly presented, and three kinds of potential external disturbance in EPMD were analyzed. To overcome the current measurement error induced by these EPMD disturbances, we put forward an improved algorithm for time-dependent measurement of EPMD by second- and fourth-order harmonic component of optoelectronic signal. A simulation experiment in different disturbance intensity were carried out, and the results showed that when measured current is between 200A~1500A,the proposed algorithm can enhance the current measurement accuracy by over 30 times than the conventional algorithm, and measurement relative deviation can be maintained below 0.2% if the disturbance intensity is below 5%.
Research on Current Control of Photovoltaic Grid-Connected Inverter
Authors: Zhang Yan , Wang Wei , Wang Shi Tao
Published: March 2013

Grid-voltage feed-forward control was added to improve the grid-connected current quality on photovoltaic grid-connected inverter. The method decreases the phase difference between the grid-connected current and grid voltage and reduces the total harmonics distortion (THD) of grid-connected current. So the grid-voltage feed-forward compensation can improve grid-connected current availably and keep the current frequency and phase synchronous to the grid. The study is validated through simulations and field experiments. Experimental results obtained on 2.5-kw inverter demonstrate the feasibility of the proposed method.
The Power Drive Circuit for a Switched Reluctance Motor Based on C8051F310
Authors: Wang Zheng Yin , Wu Zhao Ming , Zhang Xiao Chun , Liu Peng , Zhao Ying
Published: March 2013

The switched reluctance drive (SRD) is a new-type speed regulating motor drive system. It’s developed rapidly in the 1980s. The SRD is studied and designed all over the world. A simple SRD system had been designed based on the single chip microcomputer (C8051F310). The asymmetric bridge circuit is used to drive switched reluctance motor (SRM). Programming for microcomputer is based on the operation principle of SRM. Testing system could work well.
Variability Analysis of Pi Network Impedance Matching
Authors: Tan Jian Wen , Deng Si Jian , Ye Fang Wei , Zeng De Ping
Published: March 2013

Harmonic rejection ability and reflection coefficient are the most important factors in the design of impedance matching network. However, stability of impedance matching should be taken into account in applications existing load impedance variation and component deviation due to tolerance and process variation. This paper investigates variability of Pi network impedance matching analytically. The relationships between resulting reflection coefficient with component deviation and load impedance variation are theoretically derived on the basis of Q-based design method. The deviation from perfect match due to component deviation is proportional to quality factor. Higher quality factor probably means poorer quality in terms of variability. The resulting reflection coefficient caused by load impedance variation increases rapidly when the load reflection coefficient is larger than 0.66. A small variation in the load impedance will cause a large deviation from perfect match when the impedance difference between load and source is quite large.
Influence of Harmonic on the Protections of Capacitor Bank
Authors: Cen Xu , Liu Shu Ming , Li Qiong Lin , Tao Shun
Published: March 2013

This paper introduces the capacitor bank equipped with overvoltage protection and overcurrent protection. Then with a group of capacitor for reactive power compensation as the research object, this paper analyses the influence of harmonic to the two protection modes when the electromagnetic, static or microcomputer relay are applied.
Research on Identification of Voltage Interruption and Voltage Dips in HHT
Authors: Liu Guan Qi , Sun Kai Hang , Wang Fei Long , Li Yan Qing
Published: March 2013

Hilbert Huang Transform (HHT) couldn’t effectively identify voltage interruption and voltage dips. Frequency comparison method was applied to identify the two situations in this paper. The simulation results showed that the magnitude of the Intrinsic Mode Functions (IMF) components and instantaneous frequency fluctuations were not exactly the same, when the magnitude of the voltage sag was different. The magnitude of the voltage sag was larger, the average value of the amplitude of the IMF components was smaller and the instantaneous frequency fluctuations were greater. During the period of voltage interruption, the instantaneous frequency of the IMF components was almost zero and the average value of the IMF components was relatively larger. So the instantaneous frequency of voltage interruption and voltage dips different characters can help to identify the two situations and the results of the example verify to be a practicality method.
Co/ZrO2-Al2O3 Catalysts with Bimodal Pore Distribution for Fischer-Tropsch Synthesis
Authors: Zeng Shang Hong , Ding Ning , Chen Tian Jia , Yu Shi Yong , Bai Feng Hua , Su Hai Quan
Published: March 2013

The Co/ZrO2-Al2O3 catalysts were prepared by impregnation method, and characterized via quantitative XRD, H2-TPR, and N2 adsorption-desorption techniques. The study showed that the addition of ZrO2 increased the interaction between active component and support, decreased the average crystallite size of Co3O4 and improved its dispersion. The performance tests presented that the Co/ZrO2-Al2O3 catalysts with bimodal pore distribution had high CO conversion and were more selective towards the gasoline fraction (C5-C10) and diesel fraction (C11-C18).
Corrosion Failure Analysis of 35CrMo Bolt in Wet Hydrogen Sulfide Environment
Authors: Shi Hong Qi , Ding Yi , Ma Li Qun , Shen Xiao Dong
Published: March 2013

Failure analysis of fracture of 35CrMo bolt was investigated. It was analyzed by means of morphology and microstructure analysis, chemical composition analysis, hydrogen content analysis, scanning electron microscope (SEM) micro-morphology of fracture surface, electronic differential system (EDS) corrosion products analysis. The results showed that the cause of fracture of 35CrMo bolt was stress corrosion cracking. Working stress of the bolt，H2S in surroundings and the high hardness of the bolt combined caused cracking of the bolt. Suitable heat treatment for the 35CrMo bolt is suggested.
Effects of Cultivation Conditions and Media Compositions on Lipid Productivity of Native Microalga Chlorella vulgaris U3-3
Authors: Zhao Peng , Yu Xu Ya , Li Jun Jun , Tang Xian Hua , Xie Zhen Rong , Mu Yue Lin , Huang Zun Xi
Published: March 2013

A native microalgae strain Chlorella vulgaris U3-3from Baimaxueshan Yunnan province has been isolated and identiﬁed as a potential feedstock for biodiesel production. The biomass production, lipid productivity, and fatty acid compositions of U3-3 are investigated and compared under phototrophic, heterotrophic and mixotrophic conditions with various media. U3-3 under phototrophic growth on BG11 medium shows higher cellular lipid content (44.6%) than those under heterotrophic and mixotrophic conditions. And U3-3 display its higher biomass production (5.55g/L) than those under phototrophic and heterotrophic conditions growing on optimized medium with supply 35g/L glucose under mixotrophic condition. However, Chlorella vulgaris U3-3 growing under heterotrophic condition with optimized medium of supply 35g/L glucose exhibited more than 7.26-fold and 1.05-fold increase in lipid productivity compared with that under phototrophic and mixotrophic conditions. Moreover, Chlorella vulgaris U3-3 has suitable fatty acid compositions with high saturated acid contents (28.76%) and favorable degree of unsaturation (92.86) growing under heterotrophic condition with optimized medium of supply 35g/L glucose, suggesting its potential as a biodiesel feedstock on this cultivation condition and medium composition.
Efficient Production of Biodiesel from Rapeseed Oil Deodorizer Distillate: One-Pot Esterification and Transesterfication with Compound Lipases
Authors: Zhu Zhen Nan , Xu Li , Zhang Hou Jin , Yan Yun Jun
Published: March 2013

A novel concept and efficient method for producing biodiesel from rapeseed oil deodorizer distillate (RODD) was developed by using compound lipases for one-pot esterification of FFA and transesterification of triglyceride with methanol in a solvent-free system. Compound lipases Novozyme435 and immobilized Pseudomonas cepacia G63 at 1:1(wt/wt) gave FAME about 96% yield under optimal conditions, being better than that with single lipase or other compound lipases. Besides, the loss rate of vitamin E was 18% much lower than that of using chemical catalyst, which shows that the compound lipases Novozyme435 and immobilized P. cepacia G63 can be ideal catalysts for biodiesel production from rapeseed oil deodorizer distillate.
Experience of Automobile Industry Development in Japan and its Implication to China
Authors: Zhang Huai Ge
Published: March 2013

This paper studied the experience of Japanese cars went beyond American, according to the development of independent brand auto ,interposed the strategies of strengthening technical innovation of independent brand automobile, attaching weight to product quality of independent brand auto, and further adjusting automobile industrial policy with Chinese characteristics.