bluuebunny/crossref_metadata_2025 huggingface dataset:
Green Transformation Technology Suitability Research of Existing Office Building
Authors: Wang Yan Li , Wang Qing Feng , Meng Chong , Wang Qing Qin , Li De Ying
Published: June 2012

In this paper, the application status of existing building is discussed, the green transformation technology of existing building is presented, the selection method of green technology was discussed. At last, the suitability of green transformation technology for office building is analysis. The green transformation of existing office building must combine the characteristics of the green technology, according to climate characteristics and architectural features, to choice a suitable green technology.
The Use of Anthracite Fly Ash for the Production of Autoclaved Aerated Concrete
Authors: Drochytka Rostislav , Černý Vit , Kulísek Karel
Published: June 2012

Burning high-quality anthracite coal produces ash with a high content of unburned residues, which in many cases permanently exceeds 20%. These ashes usually contain high levels of amorphous phase providing the pozzolanic activity, this making them particularly useful if potentially applied in the construction industry. Such potential of effective treatment necessitates reducing the content of unburned residues, the best level here being less than 4% w/w. This paper deals with the results of testing heat treatment of fly ashes particularly using the resources of eastern Slovakia. Tests have shown that tested process of heat treatment can safely reduce the content of unburned residues in fly ash whilst maintaining high levels of the glass phase. Raw materials thus modified meet the requirements for the use in cellular concrete production technology with beneficial use of exothermic reaction heat from fly ash treatment in pre-heating the autoclaves.
Thermal Properties Analysis of Several N-Alkanes Eutectic Mixtures Applied in Building Envelopes
Authors: Huang Jing Yu , Lv Shi Lei , Zhang Chen Xi , Wang Zhi Wei
Published: June 2012

This study focuses on the preparation, thermal properties of alkanes eutectic mixtures (n-Octadecane/n-Eicosane, n-Octadecane/n-Docosane and n-Heptadecane /n-Eicosane) as candidate phase change material (PCM) for low temperature latent heat storage systems in building envelopes. Their melting temperature and latent heat were tested by Differential scanning calorimetry (DSC). The testing values were closed to calculation values of accepted theory that ensured the reliability of those datas. The results indicated n-Octadecane/n-Docosane eutectic mixture was more promising PCM for buildings in terms of melting temperature (25.3°C) and latent heat values of melting (158.2J/g).
Application Research of Method of Noumenon Sampling Detection in Strength Test on Structural Concrete
Authors: Zhang Guo Zhi , Guo Liang
Published: June 2012

Noumenon sampling, a new detection technology for strength of structural concrete, is proposed.The conversion relationship between the strength of noumenon sampling specimen and the strength of standard maintenance specimen was explored by correction coefficient and regression analysis．the conversion coefficient for concrete strength between the standard curing specimen and the structural concrete was1.08, which is less than the specification of conversion coefficient(1. 10); therefore, the test result by noumenon sampling is more accurate and reliable.
The Performance of a Combined Thermal and Electric System of Solar Energy Conversion with TEM
Authors: Liao Chun Po , Lu Jau Huai
Published: June 2012

Combined solar thermal and electric system is a combination of solar thermal system and solar electric system, such that both electric power and hot water can be produced at the same time. The solar collecting system includes a concentrator, frames, and a solar tracking system. The hot water system includes a flat collector, flow channels, water tubes, a storage tank, and a water pump. The power generation system is composed of thermoelectric modules and the associated controller. A miniature system was established and its performance was tested in this study. It was found that at the solar radiation flux of 800 W/m2, a total efficiency of 50% could be achieved. However, most of the solar energy has been converted to thermal energy instead of electricity. Our thermal electric system’s total efficiency can reach 43% and power generation of thermoelectric modules is only 0.6%.
The P-V Modified Model and Experiment of Landfill Gas Generation Rate
Authors: Liu Lei , Fan Zhi Hua , Xue Qiang , Li Jiang Shan
Published: June 2012

The Palos Verdes (P-V) modified model for gas generation rate was given, to resolve the supposition for critical point of the gas generation peak in the P-V model. The laboratory experiments of biolysis reaction with typical ratio of waste component (the organic fraction of readily degradation is 55%, 30%, and 15%, respectively) were conducted. At the first stage, the reaction coefficient k1 was equal to 0.01512, 0.00792 and 0.00756day-1, and the reaction coefficient k2 was equal to 0.0317, 0.0181 and 0.0145day-1, respectively ,at the second stage. And the initial production potential was equal to 5900, 2800, and 486 m3 /ton, respectively. The gas generation in the first stage was effected obviously by the waste component. The gas generation occurred in the first stage must be considered to evaluate the landfill gas production. Moreover, the reliability and practicability of the P-V modified model was approved by the better fitting from the simulation result and the testing data of the gas generation rate.
Anaerobic Fermentation Characteristics of Corn Straw Pretreated by Steam Explosion
Authors: Xu Gui Zhuan , Fan Shuai Yao , Zhang Bai Liang , Liu Jie Bo
Published: June 2012

The anaerobic fermentation characteristics of green and dried corn straw pretreated by steam explosion method were investigated. The steam pressure and retention time were 1.0Mpa and 90s, TS of fermentation liquid were 2% and 4%. It was shown that the fermentation cycle of green straw is shorter than that of the dried one by 4-7 days, the gas productivity of green straw is 220 mL/gVS, which is higher than that of dried one (153 mL/gVS) while TS is 2%, but there is no significant difference between the green and dried corn straw while TS is 4%, the average methane content in biogas produced from green straw is slightly less than that of the dried one.
Biogas Production from Cassava Waste Cake in a Two-Stage Anaerobic Digestion System
Authors: Promphiphak Phongphan , Wongwuttanasatian Tanakorn
Published: June 2012

This research is to produce biogas by using cassava waste cake as a feed stock in a two-stage anaerobic digestion system. The system was designed and built as a pilot-scale plant consisting of mixing tank, a fermented acid tank, two methanogenic tanks and a storage tank connecting in series. Feed stocks were mixed in the mixing tank and then fed into the fermented acid tank. The feeding was a batch feeding with a hydraulic retention time of 12 days. The system was operated to determine the biogas production rate and the net energy production. The temperature of the fermented tanks were set at 35°C during the testing period. The pH value was initially set at 8. The organic loading rate was at 0.417 g COD/ L-day. The results showed that the system can produce biogas at a rate of 140 L/day in average. The net energy production was found to be 48.52 W-h/day.
Constructon of Yeast Surface Display of ProROL by Using Flo1p Anchor System
Authors: Wang Ye , Li Wen Qian , Li Xun , Shi Hao , Wang Fei
Published: June 2012

A Pichia pastoris cell-surface display system was constructed using a Flo1p anchor system containing N-terminal flocculation functional domain (874 residues, FS), derived from Saccharomyces cerevisiae. The lipase from Rhizopus oryzae with a pro sequence (ProROL) and green fluorescent protein (GFP) gene were successfully cloned and genetically fused to the anchor system with their C-terminus free. Fluorescence microscope was used to detect the GFP displayed on the recombinant P. pastoris cell surface. The results showed that the yeast surface display system using Flo1p as the anchor protein was successfully constructed, and the activity of ProROL displayed on KM71H reached to 217.15 U/g, much higher than 61.30 U/g reported by Matsumoto. Besides, the yeast surface display system could effectively shorten the fermentation time compared with traditional fermentation.
Current Situation and Prospect of Utilization of Biomass Energy in China
Authors: Wei Yong
Published: June 2012

The development of biomass energy industry carries a great significance to alleviating the shortage of fossil energy supply, to optimizing energy structure, safeguarding national energy security, and establishing stable energy supply system. In this paper, the writer introduces basic situation and characteristics of biomass energy, then current situation of biomass energy utilization in our country is summarized, and the development prospect and significance of biomass energy are analyzed at last.
Effect of Detoxification of Natural Drying Steam Exploded Corn Straw with Organic Solvent on Enzymatic Hydrolysis and Ethanol Fermentation
Authors: Jin Xian Chun , Song An Dong , Su Tong Fu , Zhang Bia Liang
Published: June 2012

Corn straw from steam-explosion treatment process was treated with different organic solvents to reduce the inhibition for the sequent enzymatic hydrolysis and fermentation. The detoxiﬁed substrates (100 g DW/L) were hydrolyzed with a blend of Novozym 188 (15 IU/g cellulose), Celluclast CP cellulase (15 FPU/g cellulose) and lignase (15 IU/g hemicellulose). The reducing sugar was bio-converted to ethanol with separated hydrolysis and fermentation processes using Pachysolen tannophilus P-01. The reducing sugar yield varied from 34.8 to 89.7% depending on the detoxiﬁcation solvents and modes. The highest ethanol yield (96.1% of theoretical value) was obtained with the combined extraction of ether and acetone.
Effect of Particle Size on the Water-Soluble Substances and Microscopic Structure of Sorghum Straw Powder
Authors: Yue Jian Zhi , Jing Yan Yan , Zhang Zhi Ping , Zhang Quan Guo
Published: June 2012

The effect of particle size on the water-soluble substances and microscopic structure of sorghum straw powder were investigated. Sorghum straw powder with four particle size (300 ~ 450μm, 125 ~ 150μm, 97 ~ 105μm, 330 ~ 420nm ) were studied for analysing changes of water-soluble substances and microscopic structure. The results showed that with the particle size decreasing the pH value of water-soluble substances decreased, the concentration of reducing sugar in water increased firstly then began to decrease when it reached to a certain value, the crystallinity of sorghum straw powder decreased, and the degree of polymerization of sorghum straw was lowered ,respectively.
Fabrication and Characterization of CIASSe Thin Film Photovoltaic Absorbers Using CIAS Nanocrystals
Authors: Zhu Bei , Zhu Cheng Jun , Chang Shan , Zhang Yong Wen , Wang Chao Zheng
Published: June 2012

Cu(In0.8Al0.2)(SSe)2 (CIASSe) absorber layers of thin film solar cell were prepared by selenization of Cu(In0.8Al0.2)S2(CIAS) nanocrystals. The CIAS nanocrystals were synthesized by a new solution-based technique and successfully deposited on Mo-coated glass substrates in a one-step process. The phase structure, optical and electrical properties of CIASSe thin films were characterized by power X-ray diffraction (XRD), ultraviolet-visible (UV-Vis) spectrophotometer and the Hall Effect Measurement system. The results showed that single-phase CIASSe solid solution was successfully obtained for a selenization temperature of above 400oC. And the diffraction peaks shifted to the lower angle with an increase in selenization time and selenization temperature. The films selenized at 500oC were found to be p-type and the resistivity was only 0.9484×10-4Ω cm. The optical band gap of the films is 1.508eV and the optical absorption coefficient is over 104cm-1.
Effects of Temperature on Gas Production Efficiency and Fermentation Time of Anaerobic Fermentation of Pineapple Leaf Residue
Authors: Deng Yi Guo , Wang Jin Li , Jiao Jing , Zhang Jin , Peng Zhi Lian , Zheng Yong , Wang Gang , Qin Shuang Mei
Published: June 2012

A constant temperature fermentation system was self-designed and used to study the relationships of gas production efficiency with time and temperature of digestion in anaerobic fermentation of Pineapple Leaf residue. Groups of experiments were conducted with total solids concentration (TS) being 20% and fermentation temperatures of four groups respectively being 25°C, 30°C, 35°C, and 40°C. Experiment results showed that the total gas yield of the group with 35°C was 662.8 L, which was much higher than gas yields of the other groups. The methane content of the group was 63.2%, almost the same with other groups. Multiple regression analysis was made with SAS software and the regression equation was set up. The optimum temperature, digestion time and maximum cumulative gas production of solids were 36.4°C, 55d, and 462.41mL/g respectively.
Monascus anka Pyruvate Decarboxylase Accounts for the New Candidate Resources of Fuel Ethanol Production
Authors: Zhu Bi Yun , Gao Lan , Li Hao Ming
Published: June 2012

In order to study the nature and function of Pyruvate decarboxylase (PDC, E.C.4.1.1.1), which is the key enzyme to produce ethanol by fermentation; full-length cDNA library was constructed with SMART technique from Monascus anka CICC 5031. The pdc gene, including a 1713-bp open reading frame, encoding a 570 amino acid protein, was obtained by screening the constructed M. anka cDNA library. The pdc gene was successfully heterologously expressed in E.coli BL21(DE3), accounting for 32.7% of total cellular proteins. Recombinant PDC was expressed in prokaryotic cells and purified by affinity chromatography, and native PDC was extracted and purified from M. anka through Sephadex G-25 and DEAE-anion exchange resin. The enzymatic characterization of both recombinant and native PDC were studied, respectively. The specific activity of recombinant and native PDC was 20.2 and 30.11U/mg respectively. Kinetic analysis indicated that recombinant and native PDC had the same optimum conditions: pH6.0, 30°C, the Km value for pyruvate of recombinant PDC was 2.6 mmol/L and native PDC was 0.56 mmol/L. The high activity and stable PDC from M. anka accounts for the new candidate resources of fuel ethanol production.
Relationship of Substrate and Inoculum on Biochemical Methane Potential for Grass and Pig Manure Co-Digestion
Authors: Dechrugsa Sumeth , Chaiprapat Sumate
Published: June 2012

The effects of substrate mix ratio and inoculum/substrate ratio (ISR) on biochemical methane potential of para-grass (PG) and pig manure (PM) were investigated in batch test that maintained temperature at 35±1 oC and continuously shaked at 120 rpm. Cumulative methane production data at different mix ratios and ISRs were evaluated and fitted with Gompertz equation to derive methane production potential (mL) and maximum methane production rate (mL/d). The maximum and average methane yields at each respective ISR of 1, 2, 3, and 4 were [413.0, 315.5], [539.7, 455.6], [590.3, 472.5], and [593.1, 473.5] mL/gVSadded. Relationship of ISR and PG mix ratio to specific methane yield were expressed in quadratic regression model. The generated response surface showed that methane yield was elevated at higher ISR and higher PG mix ratio. This suggests a careful investigation at different ISR and substrate mix ratios should be performed in order to develop a realistic biochemical methane potential of anaerobic co-digestion.
Research on Producing the Alcohol from the Organic Garbage Fermentation
Authors: Hu Shang Qin , Hu Guo
Published: June 2012

For seeking the method of reproduction of organic garbage, the organic garbage is handled by using the enzymes of the microorganisms, and the alcohol is produced from the organic garbage fermentation. The result shows that alcohol0-9 ml can be produced from organic garbage fermentation/100 g and alcohol/70～90 L from organic garbage fermentation/1000 kg. The wast materials are changed into treasure. The problems of the energy resources is resolved and the environment is improved. lt provide a new method of reproducing the organic garbage to new energy in the city.
Research on Pyrolysis Reactors for Bio-Oil Production from Agricultural Residues
Authors: Li Zhi He , Yi Wei Ming , Gao Qiao Chun , Li Yong Jun , Bai Xue Yuan , Zhang De Li
Published: June 2012

This paper provides an updated review on fast biomass pyrolysis reactors for bio-oil production in Shandong University of Technology. The technologies that were developed include horizontal entrained bed (HEB), fluidized bed (FB), down flow tuber reactor (DFTR), double concentric cylinder rotary reactor (DCCRR) and new type down flow tube reactor (N-DFTR). The patented DFTR, DCCRR and N-DFTR in China were developed based on the technology of direct heat exchange between hot solid heat carriers and biomass particles during both of the particles flowing in a mixed condition. The process and characteristics of each reactor were discussed in this topic. Contrasting to conventional reactors, the DFTR, DCCRR and N-DFTR are promising technologies due to their characteristics of high solid-liquid conversion rate, energy self-sufficient, easy operation and scaling up.
The Instability of Vapor Bubble Growth within the Diesel Droplet under the Condition of Supercavitation
Authors: Lv Ming , Ning Zhi , Yan Kai
Published: June 2012

A new analytical form of dispersion equation which can be used to describe the disturbance growth rate of the diesel bubble growth instability is derived. The instability analysis of vapor bubble growth within the diesel droplet is carried out in this paper. Analysis results show: the disturbance growth rate is majorly influenced by six dimensionless variables. The disturbance growth rate initially decreases gradually then increases rapidly with increasing bubble volume fraction. The disturbance growth rate increases with increasing Weber number of vapor bubble growth, increasing Mach number and increasing diesel droplet Reynolds number. Both vapor bubble Reynolds number and ambient air Reynolds number have slightly influence on disturbance growth rate.
Economic Feasibility and Comprehensive Evaluation Model Analysis on Solid-Catalyzed Bio-Diesel Production
Authors: Wang Yi , Chen Guan Yi , Zhang Xiao Xiong , Li Li Ping , Yan Bei Bei
Published: June 2012

Considerable attention has been given to bio-diesel as a surrogate to fossil fuel reserves and associated environmental problems of burning them. However, the high costs of bio-diesel production remain the main problem in making it competitive. Bio-diesel and glycerol are obtained by reacting virgin vegetable oil or animal fat with an alcohol in the presence of a catalyst or non-catalyst via transesterification. A conceptual process of heterogeneous SnO-catalyzed transesterification is designed based on the condition of 333K and atmospheric pressure, using methanol and waste oil with a molar ratio of 10:1 as raw materials. In this paper, the economic feasibility analysis based on static payback time, dynamic investment payback period, Financial Net Present Value and Return on Investment, is elaborated for 10kton/y capacity transesterification units. Comprehensive evaluation model on four typical methods are done, taking the following factors into consideration including natural resource utilization, impact on environment, economic feasibility and sustainable development of society. As a result, Heterogeneous acid-catalyzed transesterification seems more transcendent.
Overview about Bio-Energy and Food Security
Authors: Xiao Mei , Liu Biao , Qiu Hua , Wang Chun Xiang
Published: June 2012

Abstract. Introducing the development background of bio-energy in our country,the present situation and trends of international bio-energy research,the bio-energy development path under the constraint of food security,telling the study meaning of bio-energy and food security problem,and doing some study and prospect on this issue to our country. Bio-energy is divided into three generations according to the extractive technology and the use of material.The first generation is based on the sugar and starch to produce alcohol or oil crops to produce bio-diesel.And it is also the bio-energy that has been realized industrialization development.The two generation is based on the cellulose or lignin to produce alcohol,but it is still on the way[1].The third generation start the study of diesel technology using the aquatic micro-algae organisms. At present the main form of the bio-energy is biogas,Boyden production,bio-diesel and fuel alcohol[2]. Because of the huge number of organisms on earth, according to biologists estimate, earth annual growth biological energy volume of about 1400 - 1800 tons ( dry weight ), ten times to the current world total energy consumption, so Bio-energy has wide use value and has great historical significance to take place exhaustible resources such as coal oil and so on.
Equal Energy Driving Principle in Fabricating Poly-Si Thin Film
Authors: Wang Yu Cang , Jin Rui Min
Published: June 2012

In this article, we have explained quantum state observed in fabricating poly-silicon the thin film and calculated the crystallization procession of rapid thermal annealing as a function of light energy. Equal energy driving principle was presented, it is shown that the change in magnetic frequency leads to the conversion of magnetic field energy to annealing energy.
Somatic Embryogenesis and Organogenesis of Biofuel Plant Cassava (Manihot esculenta Crantz) Chinese Cultivars
Authors: Li Rui Mei , Duan Rui Jun , Ji Yi Meng , Xi Du Juan , Liu Jiao , Guo Jian Chun , Zhang Peng , Fu Shao Ping
Published: June 2012

2, 4-D and picloram were compared for their ability to the induction of somatic embryogenesis in Chinese cassava (Manihot esculenta Crantz) cultivars SC5, SC6, SC7 and SC8. In all four cultivars tested, both 2, 4-D and picloram had the capacity to induce primary somatic embryos from axillary buds. And the two hormones were also suitable for subculture of somatic embryos of three cultivars SC5, SC6 and SC8. However both 2, 4-D and picloram can not keep the activity of somatic embryos of cultivar SC7. For organogenesis, cotyledon matured for 10~15 days were better than others.
The Energy Consumption and Environmental Impacts of Biomass Power Generation System in China
Authors: Song Jing Hui , Huang Ze Hao , Kan Wei Min , Zhan Zhi Gang , Liao Yan Fen , Ma Xiao Qian
Published: June 2012

Combined with practical operation of a biomass direct-fired power pant in South China, the whole life cycle of the process, including biomass growing, transportation, pretreatment, combustion power generation and power plant manufacturing are analyzed by means of LCA. The energy consumption and the impact on environment in each stage are also collected and calculated. The results show that 2182.32 MJ fossil energy is consumed to generate 104 kWh power. The total loading of the impact on environment is 13.45 PET2000 and the mainly impact on environment is soot and ashes. Compared with coal-fired power, biomass direct-fired power plant can reduce 5282.87 kg CO2 emissions during the process of generating 104 kWh power, which plays a positive part in mitigating greenhouse gases.
Design Attack Angle Analysis for Fixed-Pitch Variable-Speed Wind Turbine
Authors: Zhao Jie , Liu Xiong Wei , Wang Lin , Tang Xin Zi
Published: June 2012

The purpose of this paper is to find the optimum design attack angle for fixed-pitch variable-speed wind turbine blade design, given the base-line wind turbine and the blade airfoil. Aerodynamic characteristics, i.e. lift and drag coefficients and lift to drag ratio, of the wind turbine, are analyzed. Two design attack angles along with the base-line attack angle (with maximum lift to drag ratio) are selected for the wind turbine blade design exercise. Blade design outcomes are analyzed and compared along with load performance and power performance. This paper is possibly the first attempt to determine the optimized design attack angle for maximizing annual energy production, given the base-line wind turbine and the blade airfoil.
High-Efficiency 4kW VAWT Design and Development
Authors: Shyu Lih Shyng , Lee Ching Hai , Hsiao Yung Chia , Shih Ta Ming , Chang Chi Ching , Wang Da Yung
Published: June 2012

Emerging markets need small sized VAWT (vertical-axis wind turbine) for residential energy supplement. MingDao university wind power R&D team has developed a 4kW VAWT system is response to this need. The development items include innovative blades, generator, power control and mast design. The newly developped 4kW VAWT system demonstrates superior performance. The average VAWT efficiency is 0.31 and the average Cp is 0.39. The preliminary results showed this approach has potential for future applications.
A New Structure of Tandem Solar Cell with Amorphous Silicon and Polysilicon
Authors: Zhang Jian Xin , Liu Jun Xing , Wan You Bao , Sun Ying Hui
Published: June 2012

A new structure of a-Si/ poly-Si tandem solar cell has been desiged and prepared. Amorphous silicon has been use as photovoltaic material of bottom cell. And polysilicon has been used as photovoltaic material of bottom cell.The combination of amorphous silicon and polysilicon extends the light range which can be used by solar cell. This structure improves the efficiency of solar cell greatly.
Applying Transfer Matrix Method in Mode Analysis of Wind Turbine
Authors: Dong Li , Sun Li Xiang , Qin Ming
Published: June 2012

Mode analysis for wind turbine is more and more important with the large-scale direction development of wind turbines. Considering twist angle of blade, centrifugal force, weight of blade, weight of tower and nacelle, turbine inertia, traditional transfer matrix theory is amended and applied in the mode analysis of wind turbine in this paper. Applying amended transfer matrix theory, the mode analysis of a real wind turbine is made and the analysis results are compared with the calculation results from NREL Mode program. The comparison results show that amended transfer matrix theory takes wind turbine inertia into account and have higher accuracy.
Comparison of Construction Projects with Different Unit Wind Turbine Capacity
Authors: Wang Kai Bin , Liang Rong Jin , Xu Zi Hua , Ren Zun Yi
Published: June 2012

Development and utilization of renewable energy is important in optimize the power structure, save energy, protect environment, the development of low carbon economy has a positive role. Under the circumstances with wind machine price differ not big. The construction investment had little difference, under different capacity wind farm of the same capacity with different units. But when there is a bigger difference in wind machine price , it can be determination the rationality of the wind farm’s investment by the difference of the machine’ price preliminary. Also, it's available to estimate the whole investment. The wind farm 's permanent land area, according to the scale of wind farm, by estimating wind machines’, and the booster station, permanent land of transmission line and approach road area, then to determine the rationality of land area., on the basis of determining the wind farm project.
Linear Feedback Control Research on Hopf Bifurcation in Wind Power System
Authors: Li Ji , Zhou Xue Song
Published: June 2012

Hopf bifurcation frequently results in periodical oscillation instability in the nonlinear system. For Hopf bifurcation at equilibrium point in the wind power system, Hopf bifurcation point of the wind power system with static var compensator is calculated based on the continuation method. The analysis shows that the increase of reactive power will lead to Hopf bifurcation, static var compensation can delay Hopf bifurcation and improve voltage stability region via reactive power compensation, in order to eliminate Hopf bifurcation, a unified and simple linear feedback control method is adopted. The results indicate that the method put forward in the research is effective to eliminate Hopf bifurcation in the wind power system
Study on Noise Characteristics of Concentrated Wind Energy Turbine
Authors: Xin Hai Sheng , Yue Hai Jun , Han Qiao Li
Published: June 2012

Different types of wind turbine generate different noises in normal condition. A comparison of noises from local spot by means of modern acoustic measurement is carried out between 300W concentrated wind energy turbine and ordinary wind energy turbine, and conclusion is that the noises from the concentrated wind energy turbine are lower than that from the ordinary one. Besides, the main noises are from turbine blades and increase with the wind speed on both turbines.
Wind Speed Forecasting Using a Combined Method Based on Auto Regression and Wavelet Transform
Authors: Tong Ji Long , Zhao Zeng Bao , Zhang Wen Yu
Published: June 2012

This paper presents a new strategy in wind speed prediction based on AR model and wavelet transform.The model uses the adjacent data for short-term wind speed forecasting and the data of the same moment in earlier days for long-term wind speed prediction at that moment,taking the similarity of wind speed at the same moment every day into account.Using the new model to analyze the wind speed of An-xi,China in April,2010,this paper concludes that the model is effective for that the correlation coefficient between the predicted value and the original data is larger than 0.8 when the prediction is less than 48 hours;while the prediction time is long ahead (48-120h),the error is acceptable (within 40%),which demonstrates that the new method is a novel and good idea for prediction on wind speed.
From Chernobyl to Fukujima - A Perspective of Nuclear Safety that “Taoism Co-Works with Ziran (Nature)” - My Perspective on Nuclear Safety
Authors: Bao Tong Fa , Chen Fei Fei , Cao Jia Xin
Published: June 2012

Nuclear energy, to some extent, has made great contributions to the electronic industry when the fossil fuels are decreasing. Therefore, scientism drives man indulged in his discoveries about nuclear energy, naively believing the nuclear power as an alternative energy for it is reliable, clean, secure and economical. After the nuclear accidents which happened in the Three Mile Island and Chernobyl, especially March 2011, the world-shocking earthquake happened in Japan as well as the nuclear leakage in Fukushima nuclear plant led us to reconsider the development and application of the nuclear energy. From our perspective, how to develop the nuclear energy depends on people’s attitude towards modern science and technology. Man should step out of the limit of scientism, be aware of how much science and technology can do on human beings’ progress under the guideline of the holism that complies with nature, and how application of the nuclear energy goes well with the whole ecological system rather than partially exaggerate its achievements against nature.
In-Stream Tidal Power: A Literature Review
Authors: Kuang Cui Ping , Zhao Xu Te , Pan Yi , Gu Jie
Published: June 2012

Under the energy crisis, the development of new energy has become one of the top issues for countries in the world. In-stream tidal power is a young generation technology to exploit the tidal energy, whose potential has been attached great importance to by many countries. Turbine is the core components of the in-stream tidal power generation system. In this paper the relatively mature technology is summarized extensively. Recent years many countries have pay a lot of attentions to in-stream tidal power and set the future development goals. For both the development stage and installed capacity China have a larger gap with western foreign, but the research of the in-stream tidal power device in China already has made great progress, and the development of in-stream tidal power generation technologies has show great advantages in the protection of the environment, sustainable development of economic and social and mitigation of the energy crisis.
Modeling and Simulation of MPPT for Photovoltaic (PV) Array under Partially Shaded Conditions
Authors: Zhao Guo , Huang Xue Liang , Zhao Yong
Published: June 2012

Based on tow-diode model of PV cells, the simulation model of PV array is established. This simulation model can simulate the output characteristics of PV array according to different shading conditions. The output power-voltage curve of PV array may have multiple local Maximum Power Points (MPPs) due to the partial shading. As a result, traditional maximum power point tracking (MPPT) algorithms can easily fail to track global MPP, this can be one of main causes for reduced energy. In order to overcome this drawback, an improved global scanning MPPT algorithm is proposed. Moreover, Matlab-based model is established. It is verified by simulation results carried out that this improved MPPT algorithm is effective to track the global MPP.
State of Charge Estimation Using EKF Method for VRB
Authors: Sun Gang , Lu Jin Ding , Ye Qing , Ren Li , Shi Jing , Tang Yue Jin
Published: June 2012

Vanadium redox battery (VRB) system is a new type of energy storage system, which can be used to shave power grid peak, improve power quality, and smooth fluctuations of power and Voltage in photovoltaic and wind power systems. The state of charge (SOC) of VRB is an indication of how much energy is stored in the battery. Estimating the VRB SOC accurately in real time is very important when the battery is used to power system. In consideration of deficiencies of existing methods, a new approach is introduced to use Extended Kalman Filter (EKF) method. In this paper, state space model of VRB based on its equivalent circuit model is proposed, and SOC Estimation Using EKF Method for VRB is described in detail. By using Matlab software, it can be proved that the EKF method can estimate real-time SOC of VRB and is more accurate than existing methods.
Study on the Influence of Volute to Flow-Induced Noise in Centrifugal Pump
Authors: Si Qiao Rui , Yuan Shou Qi , Yuan Jian Ping , Wang Chuan , Yang Jun
Published: June 2012

More and more attention has been attached on flow-induced noise of centrifugal pump in recent years because of strict environmental noise restrictions and demands of clients.. In this paper, the role of volute impacted on flow-induced noise generation and propagation in centrifugal pump were summarized. The process of internal wave propagation was analyzed, and the transmission coefficient and loss of volute were calculated; In order to compare the effect of volute vibration on the sound field in a centrifugal pump, a hybrid algorithm based on CFD + BEM was adopted. The results reveals that: full reflection of sound wave occurs on the fluid-steel volute wall when the incidence angle is more than or equal to 13.8 °; otherwise a sound transmission appears; For onshore pumps, For onshore pumps the A-weighted sound transmission loss is more than 55dB under the condition that thickness volute is not less than 8mm; For submersible pumps, all-bottom sound below 3000Hz almost transmits to the outside field entirely; structure acoustic coupling between volute and the internal sound field influence little on directivity of sound field and the change of law, but structure vibration would average the sound pressure level in frequency.
Simulation Study of a Porous Overflow-Pipe (POP) Type Hydrocyclone
Authors: Zhao Xue Feng , He Li Min , Zhao Li Xin , Zhong Sheng , Wang Yang
Published: June 2012

Based on computational fluid dynamics (CFD) method, applying FLUENT software, taking a de-oil hydrocyclone as an original structure, the effect of porous overflow pipe on the performance and pressure characteristics is analyzed. Effect of overflow-pipe length and diameter of the porous overflow-pipe (POP) hydrocyclone is studied. It is found that the extension of overflow-pipe length can play a coalescent role; the new type hydrocyclone can increase oil content around overflow outlet so as to be beneficial for the enhancement of separation effect.
Experimental Study on Flow Velocity in Open Channel with Different Arrangement Submerged Flexible Vegetation
Authors: Hu Xu Yue , Yang Yi Fan , Shen Xiao Xiong
Published: June 2012

Laboratory experiments using Nortek Doppler Velocimeter were performed to investigate the characteristics of water flow in open channels with submerged flexible vegetation in different arrangements. Test results reveal that the presence of vegetation influences water level variation. No matter what kind of arrangement the vegetation is, the water level variation of vegetation area can be divided into three processes: rise, and then fall, at last remains stable. While the variation ranges of water level in interlaced arrangement vegetation area is larger than the standard arrangement. Compared with standard arrangement, the water flow velocity of interlaced arrangement fluctuates much more greatly. The higher density of equidifferent vegetation area, the lower lodging degree and water flow velocity. The lateral water flow velocity fluctuates most greatly in densely vegetation area, while at sparse vegetation area, the lateral water flow above and below vegetation layer is reverse.
Research on the Auto Cascade Refrigerating Cycle System
Authors: Yang Yong An , Yang Zhao , Xu Qiu Bo
Published: June 2012

An auto cascade refrigerating cycle system was built up in the laboratory. By changing the parameters of the operation process, the law of the operation and the effect on performance of the system were studied. When the extrinsic parameters changed, the performances of the system were measured. The paper analyzed that the evaporation temperature and the temperature of the inlet of the cooling water affect on the efficiency of the system and the pressure rate. The result shows that when the temperature of the cooling water is given, the COP of the system goes down with the decrease of the evaporation temperature. And when the evaporation temperature is given, the COP of system goes down with the increase of the condensate temperature. The pressure rate increases when the temperature of the cooling water gets higher. When both the evaporation temperature and the temperature of the cooling water are given, the COP of a R22/R23 system is higher than that of an R134a/R23 system.
Experimental Investigation on Transcritical CO2 Refrigeration System
Authors: Liu Ying Fu , Shen Peng Yu , Jin Guang Ya
Published: June 2012

The application of natural refrigerant CO2 is of great significance to reduce the greenhouse effect and ozone depletion. Transcritical CO2 refrigeration cycle is presently an important aspect of natural refrigerant alternatives research. In this paper, the transcritical CO2 refrigeration cycle system is experimentally studied, effect on performance of heat rejection pressure, gas-cooler outlet temperature and evaporation temperature is analyzed. The experimental results show that there is an optimum high pressure to achieve the maximum COP, the evaporation temperature and gas-cooler exit temperature have great impact on the COP. Increase of gas-cooler outlet temperature led to a rapid increase in the optimal high pressure, but effect of evaporation temperature is not obvious. So in order to obtain the optimum performance, the influence of heat rejection pressure, evaporating temperature and gas-cooler outlet temperature should be considered during the designing and operating CO2 refrigeration cycle system.
Optimal Configuration of Evaporative Condensers in Refrigerating Plants Based on Part Load
Authors: Zhang Jian Yi
Published: June 2012

The operating records of a typical industrial refrigeration plant in Xiamen, China are analyzed. Based on the results, the ratio of the heat exhaust of the operating condensers to that of the total condensers is calculated over each time period to obtain the regulation of part load. The energy consumption and the payback period are calculated for two typical refrigerating plants under different schemes based on the regulation of part load. Results show that energy savings will be 53.6% when condensers are optimally configured based on such regulation. The payback period is 0.8-1.7 years in some cases, whilst in other cases there is actually no additional investment required.
Vortex Tube Expansion Two-Stage Transcritical CO2 Refrigeration Cycle
Authors: Liu Ying Fu , Jin Guang Ya
Published: June 2012

Use of vortex tube as an expansion device in transcritical CO2 cycle could reduce the throttle loss and improve the coefficient of performance. In this paper, a vortex tube expansion two-stage transcritical CO2 refrigeration cycle(VTTC) is established and compared to that of the two-stage transcritical CO2 refrigeration cycle with throttle valve(TVTC). Thermodynamic analysis results indicate that there is also an optimum heat rejection pressure for the vortex tube cycle, and the COP improvement is 2.4%~16.3% at given conditions. Decrease in evaporation temperature or increase in gas-cooler outlet temperature decrease the COP, but the COP improvement will increase. The effect of cold mass fraction on the COP is negligible, but the COP improvement will increase fast with the increase of cold mass fraction.
Study of Relationship between Air Purifier Efficiency and Placement in Ventilation Environment
Authors: Han Xu , Li Yong , Liu Ying Xin
Published: June 2012

Air purifier was used more and more widely, its placement and characteristics of indoor air have a significant impact on the efficiency of air purifiers. Based on CFD software, the effect of five different ways of the placement were analyzed; according to experimental station, the effect of three cases were detected, which verified the correctness of the simulation. The results show that: the placement of the air purifier should be placed by considering the impact of air distribution, purifiers should be put in near the outlet, and far away from the return air, supply air could expand the work area of air purifier to achieve better effect It provide some basis for optimizing the use of air purifier and improving. indoor air quality.
Study on the Hybrid Liquid Desiccant Evaporative Cooling Air-Conditioning Refrigeration Circulation System
Authors: Xiong Liu
Published: June 2012

This article presents a new hybrid evaporative cooling air-conditioning refrigeration system using two-stage liquid desiccant, and carries off the theoretical study on it. Compared with the conventional liquid desiccant air-conditioning refrigeration system, the new system adopts direct mixing heat transfer technology and evaporative cooling technology instead of water-cooled or air-cooled technology. Thus the cooling water usage is reduced. Using the two-stage adiabatic absorber and using refrigerant rather than water as the cooling medium of desiccant solution, the pressure difference of mass transfer is increased. Compared with the conventional system, the heat of regenerating solution is decreased because the mass ratio of air to desiccant solution is increased which gives rise to the decline of solution's mass rate. The results of theoretical calculation show that the new system has the better performance in power consumption, usage of water and equivalent coefficient of performance than the conventional system.
A Dynamic Prediction Model for Wind Farm Power Generation Based on RBF Neural Network
Authors: Zhu Bo , Chen Min You , Xu Rui Lin , Xu Xin , Wang Qian
Published: June 2012

As a renewable energy, wind power is considered to be an important non-exhaustible energy in the times of energy crisis. Therefore, in electric power system, wind turbine generators have become important generation alternatives. As wind power penetration increases, power forecasting is crucially important for integrating wind power into a conventional power grid. A short-term wind farm power output dynamic prediction model is presented using RBF neural network with error discriminant function. Based on the wind data from a wind farm in Inner Mongolia of China, a power forecasting map is illustrated, and the errors of the model are analyzed to present the differences between dynamic model and conventional prediction model.
A Method of Evaluating Reliability of More-Electric-Aircraft Power System Using Node-Weighted Network
Authors: Zhang Peng , Ma Qi Shuang
Published: June 2012

More-electric-aircraft contains more electric equipment compared with conventional aircraft, which makes it have more complex architecture in power system. It has some characters of complex networks, needs new method to analyze. The method of evaluating reliability of more-electric-aircraft power system mentioned in [1] treats all the power load nodes as the same, which does not exactly match the actual system. In this paper, one type of node-weighted network model is proposed. In the node-weighted model, load nodes with different importance are weighted differently. The given example demonstrates that this approach is feasibly and rational.
A Summary on 2010 Smart Grid Technology
Authors: Yu Juan
Published: June 2012

According to domestic and foreign literatures, around the smart grid researching in related fields, this paper summarized the new technological achievements of domestic and foreign technologies on two aspects of smart grid scheduling modeling and smart grid control center. It includes: distributed integration modeling is one of core technologies of intelligent dispatching, the paper analysis of the verification of power grid model, maintenance of model boundary and so on, which occur during the application of distributed integration modeling, and solutions for these issue are given. And make a summary on smart Grid control center configuration, state estimation, dynamic security assessment, smart restoration control and recovery strategies, and other new technologies.
Analysis on 2nd Main Transformer Trip Accident of a Certain Substation of the West Inner Mongolia Power Grid
Authors: Ge Li Juan , Zhang Yong , Li Haijun
Published: June 2012

This paper mainly analyzes the causes of a 10KV line and 2nd transformer circuit breaker tripping, also analyzes the action mechanism of the relay protection. Because of the permanent phase fault at the head of the line, instantaneous over-current protection(SegmentⅠ) as its main protection of the phase fault made the 921 breaker triping, the action was selective.And the permanence of this fault led to the failure of the reclosing; Reversed the TA(current transformer) for measuring with the TA for differential protection in high voltage side of the transformer, this fault can also make the TA of the differential protection circuit quickly saturated when the external short-circuit current flowing through the TA. When the above saturation happens, a big differential current generating from differential circuit will lead to sampling error. This is the direct cause of the mal-operation of the differential protection which resulting in the 2nd transformer tripping. In response to this accident, put forward specific prevention measures.
Implementation of Automation Determination of Training Score for Dispatcher Training Simulator
Authors: Pan Ling Ling , Wang Yong , Li Feng , Guo Xiao Rui
Published: June 2012

Based on analyses of several evaluation schemes, difficulty coefficient subtraction method was presented. An automation determination of training score method used in DTS was given, and the implementation process was introduced in details. Furthermore, marking for trainees’ training was carried out on four aspects of dispatching operation, power supply reliability, grid security, and economy of power network operation. According to the difficulty level of teaching plan, the difficulty coefficient was determined, the relevant calculation method of trainees' training score was proposed, and the weighted score and evaluation report were presented finally. Its practical applications indicate that the marking method of trainees’ training score is reasonable, able to reflect the practice of dispatchers' operation, and easy to realize generalization, extension and maintenance through the separation between program and standard of evaluation score.