bluuebunny/crossref_metadata_2025 huggingface dataset:
Arrangement Method Research of Prestressed Concrete Slab with Unbonded Reinforcement
Authors: Pang Ping , Yin Xin Sheng
Published: August 2013

In practical projects, prestressed reinforcement are arranged in concrete slab uniformly. According to the research, a new arrangement method of prestressed concrete slab is provided. This article discussed unbonded prestressed concrete slab system, and gives the theoretical calculation method. It can save more than 50% quantities of reinforcement, and has economic advantages than before.
Comparison of Optical Smoke Density of Expanded Polystyrene without and with Cover Components Used in ETICS
Authors: Rantuch Peter , Chrebet Tomáš , Balog Karol
Published: August 2013

This paper deals with expanded polystyrene (EPS) as a potential source of smoke. We compared specific optical density of smoke from EPS and EPS strengthened by glass fibre mash and plaster which is used in external thermal insulation composite systems (ETICS). There was used testing method by ISO 5659 Plastics Smoke generation Part 2: Determination of optical density by a single-chamber test. The samples were exposed to a constant 50 kW.m-2 of thermal radiation. There was not used a pilot burner. During flame combustion samples evolved high amount of smoke. Samples from EPS released more smoke like samples with ETICS cover.
Practice of Government's Comprehensive and Whole Process Quality Supervision on Energy Efficiency Project in Civil Building
Authors: Guo Han Ding , Wei Xing , Zhang Yin Xian , Zeng Hang Yu , Men Xiu Feng
Published: August 2013

Building energy efficiency is the inevitable way to build and carry out sustainable development strategy, and it is also the inherent requirement to improve the quality of building function. The procedural law which engineering quality of building energy efficiency forms demands that it is necessary for government to put comprehensive and whole process supervision into effect, to pay attention to quality review before construction, to strengthen comprehensive supervision during construction, to be rigid when supervising on checking the quality of energy efficiency project , to be serious to handling procedures and methods of energy efficiency project supervision, and to standardize supervision reports and archives. In a word, all above are to realize continuous improvements and efficiency increasing of government supervision on engineering quality of building energy efficiency project.
Research on the Calculation Method for Diagonal Shear Capacity of Steel Reinforced Lightweight Concrete Beams
Authors: Jin Huan
Published: August 2013

Steel reinforced lightweight aggregate concrete structure is a new type of composite structure to meet the building development trend of energy conservation and environmental protection. Based on the shear tests of steel reinforced lightweight concrete beams, according to the specifications of lightweight concrete and steel reinforced concrete, this paper established a design formula for calculating the shear capacity of steel reinforced lightweight concrete beams under the concentrated loads. The results coincided well with the tests. The calculation method is reliable, which can provide theoretical foundations for the practical engineering application of steel reinforced light aggregate concrete beam.
Studies on Energy-saving Control of the Whole Process of Construction Project
Authors: Ding Yu Xian , Ma Ning Bo , Ding Yu Xin
Published: August 2013

As buildings consume large amounts of energy and thus our environment is damaged considerably, energy-saving buildings turn out to be a focused issue. As a result, reasonable approaches and methods are required to be applied to build energy-saving buildings. Moreover, the whole process of construction project must be controlled in an energy-saving way so as to maximize various benefits, thus bringing energy-saving buildings into reality.
Study on the Performance of Cushion in the Rigid Pile Composite Foundation under Flexible Load
Authors: Li Dan , Wu Di
Published: August 2013

In recent years, rigid pile composite foundation has been used as a cost effective alternative to the soft ground treatment of highway and railway in China, but limited studies were conducted on the performance of the composite foundation under embankment load, especially the cushion reinforced by geosynthetics. In this paper, 3 centrifuge model tests were performed and studied on reinforced and unreinforced cushion of composite foundation. Instrumentations were applied to investigate the distributions of displacements, earth pressures in the foundations as well as tensile forces in the model geosynthetics. Following results were found: Cushion reinforced by geosynthetics can not only reduce the deformation of embankment and foundation, but also enhance the load transference to the pile cap from foundation between piles, which means cushion plays an important role in the composite foundation; Cushion works normally because of the geosynthetics in the cushion bearing tensile force. Moreover, the tensile force of geosynthetics below the shoulder of embankment is larger than that in the center of embankment and near the toe of slope because of the lateral restraint of basal reinforcement.
The Analysis of Double-Nonlinearity Stability of Concrete Filled Steel-Tube Arch Bridge
Authors: Han Xing , Zhu Bing , Liu Gui Man , Wang Jun Ping , Xiang Bao Shan
Published: August 2013

Taking a concrete-filled steel tube arch bridge with a span of 80m for example, the paper studies the stability of this bridge by using the general finite element program. The analysis introduces the method to deal with the stability of these bridges by FEM, also demonstrates the result of the eigenvalue analysis and dual nonlinear analysis according to an example. In eigenvalue analysis, the influence of the brace and the X-brace to this arch bridge`s stability are compared under different load cases; in dual nonlinear analysis, the load-displacement curves of three different load cases of the rib failure are given. All of these are some valuable to the stability of the concrete-filled steel tube arch bridge.
Study on Temperature and Stress Development of Channel Lining Concrete in Construction
Authors: Qiang Sheng , Bie Ya Jing , Cai Hua Long
Published: August 2013

Lining of water transportation channel needs high requirements of crack prevention. The tension stress which results from temperature and other factors during construction is an important reason that causes concrete cracks. Through the simulation of concrete lining during construction period with a section of the middle route of South-to-North Water Transfer Project, it is found that concrete pouring temperature, joint space, cutting joint time always make great contributions to lining crack. Based on calculation results some pertinence measures for temperature control and crack prevention are put forward. Engineering practice shows that effects of these measures are remarkable, which means these measures have significant reference to the concrete lining construction of the same type channels.
Study on the Cyclic Loading Effects to the Railway Ballast
Authors: Wang Xue Jun , Hua Bin , Chi Yi Lin , Zhao Xue Yu , Li Fu Yu
Published: August 2013

When ballast materials are subjected to cyclic loading, as a result, the change of particles micromechanical properties will lead to ballast degradation, permanent deformations on the railways step by step. In this paper, it presented a coupling discrete particle-flow simulation model of the railway ballast for cyclic tamping loading. Tamping frequency changes from 25HZ to 60HZ in numerical simulation process. Simulation results that the ballast compaction rate increases linearly with frequency up to a characteristic frequency 35HZ and then it declines in inverse proportion to tamping frequency. The aim of this paper is to study on the effects on the railway ballast under cyclic loading. The study shows that the discrete element method is a valid method for investigation of the microscopic properties of railway ballast now, while we have no other better research method.
Laboratory Studies of the Mechanical Properties of Bolt Thread Connection
Authors: Meng Xian Zhi
Published: August 2013

Threaded connection is the weak link in the system of bolting, but it has significant impact on bolting effect. By the method of laboratory tests study the Threaded connection force and deformation characteristics, including different threaded teeth, different nut thickness and shape, different nut intensity level that impact on the threaded connection, drawn thread teeth high should not be less than 0.7H ; nut thickness is 20mm, with or without flange threaded coupling strength has little effect; the nut strength should be higher than the anchor strength a level.
Analysis of Influence of Slab’s Reinforcement on Seismic Bearing Capacity of Beam’s Cross-Section in Cast-In Situ Frame Structure
Authors: Guo Jin Shi , Jin Ju Shun
Published: August 2013

“strong beam and weak column”is the main failure states of reinforced concrete frame structure in the earthquake．This paper studies the influence on the virtual cross-section bearing capacity on extremity of frame beam in reinforced concrete in experiment through the project example and analysis of finite element method,such as slab’s reinforcement，the rigidity of frame beam, the rigidity of orthogonal beam and so on．Exploring the mechanism of slab and frame work together to determine the width of effective flange，which provides references for structural design and engineering application．
Study on Single-Axis Tracking PV System Measurement
Authors: Dong Ying Hua , Huang Jing Sheng , Liu Mei Yin , Cao Lei
Published: August 2013

In this paper, the precision test method of single-axis PV track device is proposed by analyzing generator mechanism of PV module. In the process of the rotation of single-axis track device, the change of corner in space is considered. Suitable coordinate system is built in order to evaluate track device precision which normal vector of PV module and solar direction vector can be decomposed in this coordinate system. Meanwhile, the comparison on the tracking precision of PV track devices tested by different devices is made and the test uncertainty is researched as well. Experimental results verify the effectiveness of the method which is proposed in this paper.
The Status and Trends of Crystalline Silicon PV Module Recycling Treatment Methods in Europe and China
Authors: Zhang Jia , Lv Fang , Ma Li Yun , Yang Li Juan
Published: August 2013

The disposal of PV systems will become a problem in view of the continually increasing production of PV modules. Development for waste PV modules recycling would be extremely effective in coping with this problem. In Europe, the thermal method and chemical method for PV recycling were deeply developed. The thermal treatment was to separate the module components under 600°C. The chemical treatment is to recover silicon wafers out of solar cells, which can be used again in modules. But automated separation of components and advanced chemical process needs to be studied on. In China, mechanical treatment research for PV recycling has just started. PV modules were separated and recycled by abrasive machining under the cryogenic condition and electrostatic separation. The mechanical treatment can't recycle silicon to reprocess new wafers for its low purity. Compared to the advanced technology in Europe, PV recycling in China is primary and badly in need of improving to face the huge PV module recycling demands in future.
Conversion of Fructose to 5-hydroxymethylfurfural Catalyzed by Coaled Carbon-Based Solid Acid
Authors: Zheng Rui Yuan , Liu Ning , Liu Wan Yi , Ma Jing Xin , Li Bing
Published: August 2013

Coaled carbon-based solid acid (Coal-SO3H) was prepared by sulfonating ultra-low ash Taixi coal and characterized by XPS, IR and PXRD. It was used as a new, efficient and recyclable catalyst for fructose dehydration to form 5-hydroxymethylfurfural (5-HMF) in dimethyl sulfoxide (DMSO). Reaction time, temperature and catalyst amounts were investigated respectively. The results showed that 81.6 % yield of 5-HMF achieved in dimethyl sulfoxide (DMSO) at 140 °C after 140min using the Coal-SO3H as catalyst. The ash, carbonization temperature and sulfonated way which could influence the catalyst performance for preparing 5-HMF had been investgated.
Effect of Acid Curing Agent on the Foaming of Liquefied Bamboo-Based Resol Resin
Authors: Liu Xiao Huan , Fu Shen Yuan , Xu Yu Zhi , Wang Chun Peng , Chu Fu Xiang
Published: August 2013

In this paper, effect of acid curing agent on the foaming of liquefied bamboo-based resol resin (PBF) were studied. The research result indicated that the optimal acid curing agent were mixture of p-toluenesulfonic acid and H3PO4, curing of PBF resol resin was analysized in detail and computer-aided software was applied for calculating thermodynamics characteristic of foaming process so that integrative assistantwas controlled better. Its apparent activation energy was 1.226 kJ·mol-1. The PBF foam showed satisfactory densities and compressive properties.
Experimental Study on Oxygen-Enriched Combustion Characteristics of Pure Cotton
Authors: Meng Hai Yu , Wang Shu Zhong , Chen Lin , Zhao Jun , Wu Zhi Qiang
Published: August 2013

This paper describes the oxygen-enriched combustion characteristics of pure cotton from municipal solid waste applying the non-isothermal thermogravimetric analysis, the apparent activation energy and the pre-exponential factor of oxygen-enriched combustion were obtained by kinetic analysis. Experimental results show that the pure cotton combustion process consists of two phases, which are volatile release and combustion phase and fixed carbon combustion phase. It has been found that combustion performance of pure cotton is improved when oxygen concentration increases to certain value and compensation effect exists in pure cotton combustion with the variation of oxygen concentration. The experimental results can provide direction for disposal of pure cotton as an energy resource.
Freeze-Thaw and Sulfuric Acid Pretreatment of Wheat Straw for Fermentable Sugar Release
Authors: Wang Xin Ming , Wang Lian Jie , Yu Meng , Chen Hui
Published: August 2013

Hydrolysis of cellulose and hemicelluloses of lignocellulosic materials to obtain reducing sugar can be used to produce ethanol by microbial fermentation. Effective pretreatment is necessary for optimal hydrolysis. This study investigated the positive effect of freeze-thaw treatment on low temperature sulfuric acid pretreatment for convert wheat straw to reducing sugar. Freeze-thaw treatment conditions were optimized: at -20°C for 12h, and at room temperature (25°C) for 1h, followed. After twice repeating of freeze-thaw treatment and pretreatment with 2wt% sulfuric acid for 16h at 80°C and enzymatic digestibility with 20U/g of cellulase loading, 67% cellulose and hemicelluloses were converted to glucose and xylose. The yield of furfural was decreased by 65% during sulfuric acid pretreatment. The time of acid hydrolysis was shortened by 20%.
Key Factors of Thermal Efficiency Test Protocols for Household Biomass Cookstoves
Authors: Ding Hong Yan , Liu Jia Xin , Zhang Yi Xiang , Dong Ren Jie , Pang Chang Le
Published: August 2013

In this paper, three typical test methods for thermal efficiency of biomass stoves were discussed. The effect factors such as operation process, test ending time, pot sizes, amount of water on the thermal efficiency of domestic biomass cookstoves were studied. The results show that the test ending time and the amount of water used have major impacts on thermal efficiency. The amount of water is in positive correlation with the thermal efficiency of the stove (R=0.92) when the heat needed for the selected amount of water is less than actual power output of stoves. The thermal efficiency is more controllable and accurate when the test ending time is 2 °C lower than the boiling point and the amount of water is selected according to the actual power output of stoves.
New Biogas Heater Burner 3D Virtual Design
Authors: Xiang Yang , Jiang Xiao Min , Chen Min Ye
Published: August 2013

To establish the biogas heater burner 3D virtual design platform with the software of Solidworks, a new type of biogas burner is developed using the 3D virtual design platform ,including base 1, nozzle device 2, venturi 3, premixing device 4 and burner nozzle 5, elaborated on the structure characteristics of key component nozzle device how to realize the biogas source of instability, pressure and flow fluctuation, can still achieve full combustion, stable combustion, high combustion value objective.
Study on the NaOH Modified Bagasse as Briquette Binder
Authors: Niu Yu , Wang Ren Zhang , Li Fu Ying
Published: August 2013

This The study is focused on the influence of NaOH ratio, reaction time, reaction temperature to strength of briquette binder. The results show that the NaOH ratio is 3 %, the heating time is 2 h, the heating temperature is 85°C had a great effect on the binder preparation.
Syngas Production from Biomass Gasification Using Copper Slag Catalysts
Authors: Zhang Feng Xia , Hu Jian Hang , Yang Bin , Yu Yu Nan
Published: August 2013

Catalytic gasification of sawdust biomass was carried out using a specially designed flow-type double beds micro reactor in a two step process: temperature programmed non-catalytic air gasification of biomass was performed in the first bed at 800°C followed by catalytic decomposition gasification of volatile matters (including tars) in the second bed at five different temperatures. The general observation is that the conversion of sawdust biomass increases as the temperature was raised from 750 to 950°C over non-catalyst, raw copper slag or calcined copper slag. High temperature enhances secondary cracking and reforming of tars and heavy hydrocarbons. At the temperature of 950°C, the energy yield (Ey) was 13.2 MJ gas/kg biomass; The energy conversion efficiency (Eff) was 81.05%; The H2 production was 0.0296 kg/kg biomass; The CO production was 0.6685 kg/kg biomass. Furthermore, improvement in conversion of biomass is observed when copper slag is added in secondary reactor as catalysts. The use of copper slag as catalysts significantly contributes to tar conversion in lighter hydrocarbons.
The Effect of Light on the Growth and Product Accumulation of Chlorella
Authors: Lu Bi Lin , Li Ming Xi , Qi Liang
Published: August 2013

Microalgae are microscopic heterotrophicautotrophic photosynthesizing organisms with enormous potential as a source of biofuel. In the masses of biomasses, microalgae has the advantages of high lipid, large biomass, short growth cycle and easy cultivation and with microalgae as the raw material. Light condition is crucial to cultivation of microalgae.In this paper, the microalgae strain of Chlorella sp. was supplied in BG11 medium, and Cultivation optimization were experimented. The results were showed that growth of chlorella was associated with a saturated light intensity, light intensity which was suitable for the growth of chlorella was 2000Lux. Growth of chlorella required an appropriate light-dark alternation to facilitate matching of photoreaction of photosynthetic process with dark reaction of photosynthetic, appropriate light-dark photoperiod of illumination time which was suitable for the growth of chlorella was 12:12.
The Interaction Mechanism of Biomass and Coal Co-Gasification
Authors: Hao Jia , Wang Qi Min
Published: August 2013

The development of biomass and coal co-gasification technology not only helps to alleviate the energyshortage crisis, but also reduces the pollution of fossil fuels to ecological environment. Co-gasification of biomass and coal can overcome in a certain extent tar emerge in biomass gasification, alkali chloride corrosion, low reaction temperature etc, can increase the calorific value of the gasified gas, can also improve the gasification characteristics. However, due to the biomass compositions differences and the gasification technologies differences, there are the different studies results of co-gasification of biomass and coal. This paper summarized and analyzed the biomass and coal co-gasification study literatures, it is conclude that the biomass compositions can enhance the coal gasification reaction if the biomass compositions intensive mixed with the coal compositions. If not, the biomass gasification and the coal gasification would react separately. This conclusion provides a theoretical basis of the biomass and coal co-gasification and accelerates the biomass gasification technologies development.
The Study of Oxidative Stability of Castor Oil Based Biodiesel
Authors: Yang Yun Feng , Hu Guo Sheng , Chen Yin Jie
Published: August 2013

The oxidative stability of castor oil based biodiesel, added different antioxidant, was studied systematacially through pressure differential scanning calorimetry (PDSC), accelerated oxidation test, constant temperature method, programmed temperature method. The result shows after adding antioxidant in castor oil, the generation of hyperoxide and acid value were suffocated for the biodiesel. When the content of antioxidant 300 was 0.6 wt.%, the initiation oxide temperature raised to 197.7°C, the acid value reduced to 1.41, the solubility of oxide reduced to 1.40mg/100mL, and the activity energy of oxidation was 48.18kJ/mol.
Analysis of Chemical Constituents of Volatile Oil Fruit of Cinnamomun amphora(L．)Presl GC-MS
Authors: Zhang Chi , Liu Xing Ping
Published: August 2013

Objective : Cinnamomun amphora(L.)Presl is a kind of one of the important economical tree species and valuable timber species in southern China,It had important meanding to analyze its volatile oil consitituent on expanding its utilization and increasing the added value.Methods:The volatile compounds of Fruit of Cinnamomun amphora(L.)Presl were isolated with steam distillation,and identified by capillary GC/MS /DS and the relative contents of the constitons were detemined by area normalization method. Rusults: 60 volatile components were identified and determined,accounting for 94.69% of the total area of the peaks.Conclusion: The main volatile compounds are: Methyleugenol,Safrene Eucalyptol,Caryophyllene ,Terpineol,Sabinene ,πSelinene ,L-4-terpineol,α-πPinenα-,πTerpieol,Myrcene,Gamma terpinene,πSelinenol,Alloaromadendren,Isoledene,2-Carene,π-Cadinene .
Analysis of Environmental Cost Accounting of Forest Biomass Power Generation
Authors: Huang Lei , Cao Jian , Wang Yu Bin
Published: August 2013

This paper firstly analyzes the situation of forest biomass power generation in China. Then the environmental cost of forest biomass power generation is quantitatively accounted in the base of environmental value standard and the advantages of forest biomass power generation are presented through comparing environmental cost between forest biomass power generation and other various power generation forms. In the end, competitive power of forest biomass power generation is preliminary studied and the paper concludes that the competitiveness of forest biomass power generation is reduced automatically without complete internal accounting for environmental cost.
Base-Catalyzed Transesterification of Soybean Oil by Ultrasonication
Authors: Gao Ming , Gao Qing Gang
Published: August 2013

Biodiesel is a renewable, biodegradable, and nontoxic fuel. At present, biodiesel is primarily produced in batch reactors in which the required energy is provided by heating accompanied by mechanical mixing. Alternatively, ultrasonic processing is an effective way to attain required mixing while providing the necessary activation energy. Biodiesel was synthesized by soybean oil using ultrasonication and alkali-acid catalysis method. Its structure was characterized by gas chromatograph, and the effects of various factors on transesterification rate were studied. The results show that a biodiesel yield in excess of 97% can be achieved in 30 min, methanol/oil molar ratio of 6:1, 1% of alkaline.
Establishment of Methanogenesis Dynamics Model in the Process of Methane Fermentation with Manure Wastewater
Authors: Chen Hong Lei , Yang Gui Hua , Chen Jia Chuan , Liu Yu
Published: August 2013

Anaerobic fermentation experiment was carried out with manure wastewater to produce biogas by using six parallel glass digesters system. Basic process conditions were chosen reference to previous studies. Based on the theory of methane fermentation, a prediction model was deduced, which can be used to forecast methane production according to a few of process parameters. In the experiment, two pivotal parameters involved in model were calculated, the sludge yield coefficient (YH) is 2.829×10-2 and the sludge digestion coefficient (Kd) is 0.0215. The certain parameters, such as the oxygen equivalent (λ), the difference of COD between influent and effluent (D), the volume of fermentation broth (V), YH and Kd were substituted into prediction model, and then got the methanogenesis dynamics model in the process of methane fermentation by manure wastewater.
Optimization of Simultaneous Saccharification and Fermentation for Ethanol Production from Steam-Exploded Cotton Stalk
Authors: Zhang Qin , Li Yan Bin , Liu Zhan Wen , Pu Yun Feng , Xia Li Ming
Published: August 2013

Steam-exploded cotton stalk was used as raw material in ethanol production through simultaneous saccharification and fermentation by Penicillium Q59 and Saccharomyces cerevisiae P1. The fermentative conditions were firstly examined by single factor experiments to determine the central point in Box-Behnken design, which was explored with expectation to get optimized fermentative conditions for enhancement of ethanol production. The results of optimized fermentative conditions were determined as follows: fermentation time was 10.5 days, bran added percent was 15%, initial pH value was 5.5. Under the optimal conditions, the experimental yield of ethanol was 99.85 ± 4.21 g·kg-1SECS (steam-exploded cotton stalk), which was close to the theoretical predicting value, it showed the model was feasible. The research results will provide technical reference for further exploitation of cotton stalk.
Physico Chemical Analysis of Linseed Oil and its Blends as a Potential Fuel for Diesel Engine
Authors: Rai Ashutosh Kumar , Chauhan Bhupendra Singh , Kumar Naveen , Cho Haeng Muk , Pandey Amrita
Published: August 2013

To address the twin problems of fast depletion of fossil fuels and environmental degradation, there is an urgent need to reduce dependence on petroleum derived fuels for better economy and environment. Adaptation of bio-origin alternative fuels can address both these issues. Liquid bio-origin fuels are renewable fuels coming from biological sources and have proved to be a good substitute for petroleum derived oil and environmentally-sustainable solution. To sustain agricultural and agro-engineering needs blends of linseed oil with diesel is a better solution. Present study shows the comparative assessment of physical and chemical analysis of Linseed oil and its blends asa potential fuel for internal combustion diesel engine. To understand diesel engines fuel properties of vegetable oils and comparable physico-chemical properties such as calorific value, kinematic viscosity and density were measured for different fuel blends to predict its suitability as replacement or extender of mineral diesel. The fatty acid composition was measured by using a chromatograph. From the results, it is clear that the physico-chemical properties of linseed oil lies in close resemblance with lower calorific value high viscosity. When blended in the v/v ratio of 5%, 10%, 15%, 20% its calorific value decreases with increase of percentage blends, whereas viscosity and density increases with increase of blend ratio. Linseed oil hence can be recommended as a potential fuel for Diesel engine in neat or blended form without any major change in present design, in the hour of energy need.
Preparation of Small Molecular Hemicelluloses from Coconut Shell
Authors: Wang Zhen , Zhao Feng Hui , Guo Yu Qiang , Chen Yong
Published: August 2013

A kind of small molecular hemicellulose was prepared from coconut shell by ultrasound-assisted and alkaline hydrogen peroxide extraction. Unlike the common hemicelluloses and celluloses, it is similar to liquid for the hemicelluloses in ethanol solution, but insoluble in it. Through the gel permeation chromatography (GPC) analysis, it was found that its molecular weight is much lower than that of the traditional hemicelluloses, indicting the lower polymerization degree. But from the infrared spectroscopy spectra analysis, this type of small molecular hemicelluloses has the similar infrared spectrum characteristic peaks to that hemicellulose.
Solid Super Acid Base Co-Catalyzed Transesterification of Soybean Oil Using Ultrasonication
Authors: Gao Ming , Gao Qing Gang
Published: August 2013

Biodiesel is a renewable, biodegradable, and nontoxic fuel. At present, biodiesel is primarily produced in batch reactors in which the required energy is provided by heating accompanied by mechanical mixing. Alternatively, ultrasonic processing is an effective way to attain required mixing while providing the necessary activation energy. Biodiesel was synthesized by soybean oil using ultrasonication and alkali-acid catalysis method. Its structure was characterized by gas chromatograph, and the effects of various factors on transesterification rate were studied. The results show that a biodiesel yield in excess of 98% can be achieved in 30 min, methanol/oil molar ratio of 6:1, alkali-acid catalysis includes 0.5% of NaOH and 0.5% of solid super acid.
Direct Drive Permanent Magnet Synchronous Wind Generator Maximum Power Tracking Control
Authors: Zhang Jia Ying , Zhang Li Ping , Xiao Gui Ling
Published: August 2013

Direct drive permanent magnet synchronous generator have the advantages of direct drive, simple structure, high efficiency and so on, in which make it become one of mainstream models within MW wind turbine presently. Making the direct drive permanent magnet wind power generation system as the main research object, based on the principle of the operating characteristics of direct drive permanent magnet synchronous wind generator ( DDPMG ), establish mathematical model of the whole system including wind velocity, wind turbine, direct drive permanent magnet synchronous generator and machine side converter, Appling the method of stator flux orientation to make the study of vector control strategy, to build the simulation model of direct drive permanent magnet synchronous generator system with Matlab and simulate when wind speed changes by step, the results validate the reasonableness of the model and the correctness and feasibility of the control strategy.
Development of a Wind Power Generation Experiment Device
Authors: Geng Yao Hui , Yu Dan , Lv Jiang
Published: August 2013

This paper presents a multi-functional wind power generation apparatus, which is suitable for doing fundamental experiment in university laboratories. The laboratorial apparatus has features of being stable, visualized and convenient in exhibiting the entire process of wind power conversion and its utilization. Moreover, the experimental device can display the relationships between its output powers and several characteristic parameters, including wind speed, blade number, wings shape, wings length, pitch angle, load and tip-speed ratio, etc. The wind wheels adjustable performance was emphasized by changing the blade length, blade angle and blade number within the same hub. The wind power generation apparatus provides various options for many experimental projects and corresponding experimenters. Meanwhile, it meets different levels of experimental teaching requirements.
Improve the Forecast of Surface-Layer Wind in Wind Power Farm with WRF-3DVAR
Authors: Wang Ying , Yang Yi , Zhang Fei Min , Yang Li Li
Published: August 2013

Numerical Weather Predication (NWP) is the main way to forecast the surface-layer wind of wind power farm. In order to improve the accuracy of the forecast with the existing observations, the WRF-3DVAR is used in two-way nested simulations with the data from National Centers for Environmental Prediction (NCEP) Final (FNL) Operational Global Analyses as initial and boundary conditions. Conventional data (sounding and surface observation) are assimilated through 3h assimilation cycles. The impacts of assimilation are examined through direct verification of the forecasts against the observations from conventional stations and the wind tower. It is found that the data assimilation can improve the accuracy of the forecast of surface-Layer wind up to 36h, and the improvement at conventional stations is more prominent than that at the wind tower.
Mechanism of Large Scale Cascading Trip-Off of Wind Turbine Generators
Authors: Zhou Ling , Song Xiao Fang , Xu Hai Bo , Chang Kang , Li Ji Chen , Chen Yong Hua
Published: August 2013

This paper analyses the mechanism of large scale cascading trip-off failures of wind turbine generators in China, focuses on the reasons of trip-off caused by overvoltage. It analyses the model of Doubly Fed Induction Generation (DFIG) and builds a model of a wind farm that is composed of Doubly Fed Induction generators in DIgSILENT. The wind farm A with capacity of 175MW and wind farm B with capacity of 175MW is accessed to the nine bus system. The simulation reproduces the processes of the cascading trip-off of wind turbine generators caused by undervoltage and overvoltage. The trip-off caused by undervoltage is due to the lack of Low Voltage Ride Through (LVRT). And that the capacitive reactive power compensation device is not timely removed leads to a large surplus of reactive power, then the voltage rises, so the wind turbine generators trip off because of overvoltage. By setting the contrast scenario, the result shows that if capacitive reactive power compensation device is promptly removed after the loss of a large amount of active power, the wind turbine generators will not trip off because of overvoltage.
Vibration Analysis on the Megawatt-Class Wind Turbine Based on the Rigid-Flexible Coupling Model
Authors: E Jia Qiang , Chen Yan , Wang Shui Hui , Li Zhen Qiang , Qian Cheng
Published: August 2013

The rigid-flexible coupling model of wind turbine was established in ADAMS to study the vibration characteristics, which was based on the working principle of megawatt wind turbine. The natural frequencies and vibration modes of the tower have been obtained by dynamic simulation analysis and vibration analysis of the wind turbine. The comparison of the first-order bending natural frequency by raley analysis algorithm and the first-order bending natural frequency by the software, which has validated the correctness of rigid-flexible coupling model of wind turbine, the analysis of vibration characteristic has verified the rationality of the structure of the wind turbine.
Control Strategy of Wind Turbine Power Limitation under High Winds
Authors: Wu Chang Ming , Zhang Jun
Published: August 2013

This paper analyses the control strategy of different wind turbine power limitation in high winds. And the active power regulation method is summarized into: Start-Stop control, yaw control and pitch control. There are also some analysis and comparison of these three methods. It is pointed out that if the wind farm's main control system of wind turbine cant be modified, Start-Stop control strategy can be used for limiting the power via remote monitoring. Accordingly, this article provides a feasible start-stop control strategy. For the wind turbine whose main control system can be modified, this article gives feasibility analysis of yaw control and pitch control application. And only pitch control solution is suitable for limiting the active power. Accordingly, pitch control strategy is given in detail.
Detection of Flicker Caused by Wind Farm Based on Mathematical Morphology Filter and Hilbert-Huang Transform
Authors: Xu Tong Yu , Zhen Hong Fang , Wang Li Di
Published: August 2013

Voltage fluctuation and flicker are among the most serious impacts of wind power generation on power quality. To assess and suppress voltage fluctuation and flicker, an accurate detection method is necessary. According to characteristics of flicker caused by wind farm, a systematic, accurate and fast flicker detection method was introduced. First, with Mathematical Morphology (MM) filter, noises contained in flicker signal were filtered out. Then to the filtered flicker curves, a track method based on Hilbert transform was adopted to pick out the flickers envelope which is the base of attaining relevant parameters of flicker. At last, the envelope was simultaneously analyzed in both time-domain and frequency-domain by a novel non-stationary signal processing method, the Hilbert-Huang transform (HHT). Simulations show that with this method, time, frequency and amplitude information of non-stationary flicker signals can be accurately detected and the proposed method is effective in the analysis of flickers caused by wind farm.
Research on Fault Diagnosis Method of Wind Turbine Based on Wavelet Analysis and LS-SVM
Authors: Liu Chang Liang , Qi Wei Xue
Published: August 2013

Aiming at the fault characteristics of high-speed gearbox fault diagnosis of wind turbine, a fault diagnosis method of combining wavelet analysis with least square-support vector machine (LS-SVM) is proposed. According to the method, the energy of frequency bands generated by wavelet decomposition and reconstruction of the high-speed gearbox's vibration signals in different fault states is normalized as eigenvectors, forming training and testing samples of LS-SVM fault classifier. Train the LS-SVM fault diagnosis model with the training samples and test the accuracy with the testing samples. The result of research shows that the fault diagnosis method based on the wavelet analysis and LS-SVM has good diagnostics effect.
Strength Analysis of Bolt Connection on Yaw Gear of the MW Wind Turbine Generator System
Authors: E Jia Qiang , Li Zhen Qiang , Qian Cheng , Chen Yan
Published: August 2013

The 3D model of bolt connection between flange and yaw gear was established in Pro/E and pre-processed in Hypermesh. Then build the contact model of bolts in ABAQUS and analyzed the statics performance by taking different preload in two kinds of working condition, which stimulated the preload and limit load condition. The results show that, through comparing the stress strength under different preload condition, the author puts forward a value range of preload for reference: Fv = (0.6~0.8) AS · σp0.2. The research provides a reference for strength check, fatigue analysis etc. of the bolt connection on yaw gear of the MW wind turbine generator system and other bolt connection systems, to facilitate further optimal design.
The Coordination Control Method of Dynamic Reactive Power Compensation Equipment Based Multi-Objective
Authors: Sun Ya Lu , Liu Wen Ying , Wang Ning Bo , Ma Yan Hong
Published: August 2013

According to the operation features that voltage of wind farm fluctuate greatly, we analyzed the operation features of reactive power compensation equipment and put forward the coordination control method of compensation equipment. The method solved the problem for a single for reactive compensation equipment caused by the slow speed and poor economy. Based on the target of safe and economical operation, we raised that using composite indicator calculate the capacity of all kinds of required compensation equipment, and then we had coordinated control to compensation equipments. This paper gave an example of Guazhou Gansu and tested and verified the feasibility and effectivity of the method.
Wavelet Packet Diagnosis for Wind Turbine and Vector Control for Wind Power Generation System
Authors: Hou Zhao Ran
Published: August 2013

Wavelet transform was a signal analysis method from domain of time-frequency which was better in the wavelet packet, vibration signal was a carrier of fault features of the wind turbine driving chain, can effectively reflect most of the fault information of the wind turbine drive train. Wavelet transform for feature extraction was proposed as the characteristics of wind turbines in the presence of a large number of transient and non-stationary signals. The SCIG vector control system was designed and the simulation result shows this control system can realize optimal control for large wind energy conversion system which can effectively applied into SCIG wind power generation system for system modification.
Application of Power Communication System in Wind Power Plant
Authors: Shi Rui Jing , Fan Xiao Chao , Li Feng Ting , Wei Bo
Published: August 2013

The application of power communication system in the field of wind power mainly includes the overall system communication and local field communication. During the operation of wind farms, the total system requires that the electric power communication system should provide reliable rapid information channel, accuracy of transmission on a variety of digital business. This article will focus on the application of power communication system between the wind turbine and the booster station, which includes optical fiber communication, communication and leased public circuit, as well as the cable communication, wireless communication, microwave wireless communication. Finally, in the premise of various communications comparison, according to the actual situation of the wind power field, the network transmission rate and reliability should be considered to the requirements of power market.
Optimization Design and Analysis for the First Wall of CH HCSB TMB Based on Thermal Hydraulic
Authors: Cao Hao Ran , Huang Rong Hua , Li Jun Heng
Published: August 2013

The thermo-hydraulic performance of the first wall for CH HCSB TMB was investigated, corresponding analysis have been carried out using CFX, a computational fluid dynamics (CFD) code. The simulation results show that the maximum temperature 565°C of the FW is slightly above the allowable temperature limit 550°C of material. Base on the results so far, a modified design of the FW was presented, in which the radial-toroidal direction of cooling channels was changed to radial-poloidal. The thermo-hydraulic computational results show the temperature of the FW with modified design decrease over all, and the maximum temperature 504°C was below the allowable temperature limit for structural material. It is found that the modified design for the FW is reasonable so that the FW is effectively cooled.
The Experimental Research on Uniformity of Argon Inductively Coupled Plasma at Different Cylinder Heights
Authors: Wang Song Bai , Zhang Xian Hui , Wang Hong Zhe , Liu Lin Ying , Zhou Ren Wu , Yang Si Ze , Liu Dong Ping
Published: August 2013

We report on the characteristics of argon inductively coupled plasma (ICP) for the ITER neutral beam injection system. In argon ICP, it was found by using Langmuir probe that the radial distribution of electronic density (Ne) was uniform while the radial distributions of both electron temperature (kTe ) and electric potential (VP) were non-uniform. The former depend on two factors: the variation of Ne was small, and the value of Ne was very large. The latter is owing to the generation and disappearance of the negative ions in the ICP, where the additional dynamic processes produce the instability. In addition, both kTe and VP profiles were very similar at the cylinder height H=14 cm, which proves the plasma sheath theory to some extent. Finally, both kTe and VP began flatter with the reduction of the cylinder height, which is owing to the decrease of the negative ions in the ICP.
Analysis of the Safety of Nuclear Power Plants
Authors: Liu De Wen , Zheng Jian Xun , Chen Zhi Ke , Liu Liang Kun
Published: August 2013

Nuclear energy is a carbon-free, clean and efficient energy. It is very important in the progress of human civilization and modern development of the world, however, there are still some problems such as nuclear leak and nuclear waste. In this paper, the worlds nuclear energy utilization and nuclear power plant constructions are reviewed and plans are forecasted. The basic reason of previous nuclear power plant accidents in history is summarized. Taking 2011 Tohuku earthquake-fukushima nuclear power station accident as an example,threats to the nuclear power plant by earthquake are investigated and impacts on social, economic and ecological environment caused by nuclear power station accident are analyzed. This paper drew lessons from previous accidents and put forward a variety of countermeasures which are from both the technical and management aspects. We also appeal people all over the world to respect the nature, enjoy the nature, and to create and enjoy the new civilization of human beings.
Sustainable Development of Nuclear Energy and Study on ADS in China
Authors: Zhao Jing , Yang Yong Wei , Fu Yuan Guang
Published: August 2013

As is well known, the disposal of high level nuclear waste is one of the key issues restricting the sustainable development of nuclear energy in the world. The partitioning and transmutation strategy (P&T) has been considered as an alternative for the disposal of high level nuclear waste in future advanced nuclear fuel cycles. For the transmutation of high level nuclear waste, accelerator driven sub-critical system (ADS) has been regarded as the most feasible choice. In this paper, the main technical characteristics of ADS system are described, the world research status and development trends of ADS are introduced, and ADS study plans in China are discussed.
CFD Investigation into Internal Flows of PEM Fuel Cell for Optimal Performances
Authors: Peng Zhi Jun , Choopanya Pattarapong
Published: August 2013

It is the objective of this study to present the 3-dimensional comprehensive computational fuel cell dynamics (CFCD) model of a scaled-down single PEM cell featuring a nominal active surface of 0.0004 m2 for both conventional and serpentine flow field designs. The performance of these two designs are then analysed and compared keeping both anode and cathode inlet gases fully humidified. Then the parallel flow field was modelled under different inlet gas relative humidities (RHa/RHc) representing saturated, moderate, and dry conditions to observe the gain in cell performance. The higher pressure drop of the serpentine flow-field was demonstrated and the magnitude of which might seem to be negligible in the range of 100 Pascal. The simulation results show that a parallel flow-field design with appropriate humidity level can compete with the serpentine counterpart and gives considerably lower pressure drop across the cell. With a grid-independency analysis, it is suggested for the computational power available, the percentage error of important variables (species concentration and averaged current density) between the reference and finer mesh is negligible (< 3%) and the solution time is considerably less.
Hydrogen Production via Sorption Enhanced Steam Reforming of Acetic Acid: A Thermodynamic Study
Authors: Fu Peng , Yi Wei Ming , Li Zhi He , Bai Xue Yuan
Published: August 2013

The reaction thermodynamics of sorption enhanced steam reforming (SESR) of acetic acid as a model compound of bio-oil for hydrogen production were investigated and contrasted with acetic acid steam reforming (SR). The most favorable temperature for SR is approximately 650 °C. However, the optimum temperature for SESR is around 550 °C, which is about 100 °C lower than that for SR. The highest hydrogen concentration from SR is only 67%, which is below the basic requirement of hydrogen purity for fuel cells. In SESR, hydrogen purities are over 99% in 500-550 °C with a calcium oxide to acetic acid molar ratio (CAMR) of 4 and a water to acetic acid molar ratio (WAMR) greater than 6. The results show that hydrogen production from sorption enhanced steam reforming of acetic acid should be a promising direction.