bluuebunny/crossref_metadata_2025 huggingface dataset:
Ion Exchange Behaviors of Ca(II) and Mg(II) on Lewatit MonoPlus TP 207 and TP 208 Chelating Resins
Authors: Jiang Shuang Ying , Gao Bin , Dong Bin
Published: October 2011

The protonation process, the adsorption equilibrium process, the adsorption isotherms and the adsorption kinetics of adsorbing Ca(II) and Mg(II) onto Lewatit MonoPlus TP 207 and TP 208 chelating resins were studied using the pH titration method and batch experimental method. By omitting the ionic charges, first protonation constants, second protonation constants and equilibrium constants were determined. The adsorption behaviors were found to be dependent on contact time, pH, temperature and initial concentrations. The experimental adsorption isotherms were fitted using both the Freundlich and Langmuir models. The adsorption kinetics was described by means of the pseudo-first-order and pseudo-second-order kinetic models. The adsorption mechanism was found to involve intra-particle diffusion and film diffusion, where both were found to be the rate control steps.
Hybrid Electric and Battery Electric City Buses Benefit Analysis Based on Lifecycle Cost and Emission
Authors: Wang Ning , Gong Zai Yan , Ma Jun
Published: October 2011

This paper took hybrid electric bus and battery electric bus as research subjects, built lifecycle cost model based on purchase cost and using cost, calculated well-to-wheel carbon dioxide emission based on GREET model, analyzed current situation and foreground of new energy buses compared with conventional diesel bus. The results shows hybrid electric bus has advantages on cost and emission in the coming decade. While lifecycle cost of battery electric bus is too high today, and the cost in the future depends on battery technology development.
Research of Using Sodium Alginate Fossilization Sphingosine sphingomonas Strain Pellet to Degrade COD of Cultured Seawater in Rizhao
Authors: Zhu Ping Hua
Published: October 2011

The sodium alginate fossilization Sphingomonas strains have double features: the biological absorption and biological degradation. And through using them to remove COD in the seawater we can see the pH value has highly significant impact on the removal rate, in addition, when the temperature is 37°C, pH value is 7.0, the pellet concentration is 1.0 g/L, the rotating speed is 120 r / min and oscillate for 90 min, the removal effect is the best. Pure strains, embedding micro-organisms have better removal efficiency of COD, indicating that microbes play a major role on the removal of COD, and microbial removal efficiency is the best after cultivated for 24 h, for microorganism is in the strongest logarithm phase at that time. However, the adsorption of COD mainly comes from functional groups on the surface of sodium alginate adsorption. The removal rate of COD in seawater treated by immobilized thallus can reach 86%, and can reach Class Ⅱseawater quality standards after purified. The study has the features of maintaining the multi-enzyme system of microbial cells, having less effect on microbial activity and also having obvious treatment effect; furthermore, its operation is simple, it requires less equipment and with lower prices.
Gas Control Technology for Fully Mechanized Face of Outburst Coal Seam with Hard Roof during Initial Caving
Authors: Fu Ju Gen , Wu Wei , Hua Gen Yong
Published: October 2011

In the fully mechanized working face, with working face forward, gob area become bigger and bigger, when the top area reach a certain span ,roof in gob suddenly cave, outspreading a large quantity of mine gas, easy to cause the gas overrun and gas accidents. In addition, shock pressure which is caused when large area roof cave, easily causing casualties and damage of equipment. This paper introduces Pan three Coal mine 17171(1) ore advance of fully mechanized working face presplit blasting, rotating stoping and comprehensive extraction technologies, which successfully solve the roof management and the gas problems during initial release, achieving good security benefits.
China Oil Price-GDP Elasticity Coefficient and Optimal Strategic Petroleum Reserve Scale Analysis
Authors: Gao Dan , Li Zheng , Yang Cheng Gang , Liu Pei , Ma Lin Wei , Xu Hong
Published: October 2011

The rising international oil prices will cause the loss of national GDP and the establishment of strategic petroleum reserves (SPR) could avoid this loss as much as possible. The oil price-GDP elasticity coefficient is an important parameter in calculating strategic petroleum reserve, but since it is difficult to obtain, it is also hard to calculate. This paper provides the fitting formula of oil price-GDP elasticity coefficient based on the regression analyzing of literature data. China’s oil price-GDP elasticity coefficient in recent years has been analyzed and predictions for future trends in different situations have been made. Finally, the predicted oil price-GDP elasticity coefficient is used to calculate the size of China's strategic petroleum reserve and its earnings.
Research on the Generation Expansion Planning in Carbon Market in China
Authors: Song Xu Dong , Zhang Feng Shuo , Mo Juan , Wang Xiong , Xiang Tie Yuan
Published: October 2011

The model of GEP in carbon market is established by introducing the carbon economy index proposed in this paper to traditional GEP model. Considering the operation experience of European Union Emission Trading System (EU ETS), the proposed index mainly consists of the CO2 emission load and the carbon price, which works as two forms in the established model: the carbon income in objective function and the CO2 reduction constraint in constraints. Especially, this paper divides the CO2 reduction constraint into two parts working in different planning period, so as to provide the flexibility and the result control for the planning. And the simulation shows that the GEP in the carbon market can guide the power structure adjustment and reduce CO2 emissions.
The Application of the Complex Modulation Zoom-FFT Based on Complex Analytical Bandpass Filter in Interhamonic Detection of Power System
Authors: Liu Ya Mei , Yang Hong Geng , Li Lan Fang
Published: October 2011

Interharmoics are the signals whose frequencies are between two harmonics. Besides the usual characterics of the harmonics, interharmonics will influence the present harmonic compensating equipment, and then result in failure compensation. Therefore, precise detection of interharmonics is very important and significant. Complex modulation Zoom-FFT (ZFFT) based on complex analytical bandpass filter is introduced in the real-time detection of the power system. Contrasting to the traditional zoom spectrum algorithms, the proposed algorithm is more suitable in the intensive spectrum analysis. Detailed theoretical analysis and simulation results are presented. The effectiveness of this algorithm is verified.
Simulating Research on a New Current Controlling Method
Authors: Peng Jin Jie , Fan Xiao Ping
Published: October 2011

A new current detecting algorithm is proposed in the paper, which is applied in an improved hybrid active power filter. The filter equipment can be applied in high voltage system to suppress harmonics and compensate reactive power. The topology and filtering principle of the filter equipment is given. The harmonic suppressing function is adopted to analyze the influence by the grid impedance, quality factor and losing resonance of the resonance circuit. The feasibility of the proposed system is validated in theory. A single-phase current detecting method is also proposed. The corresponding current control is formed combined the DC-link current detecting method. The simulating results prove that the system is feasibility and the current control is validity. Harmonic and reactive power are suppressed well.
CMA the Key Equipment for Condition Monitoring in Power Transmission and Transformation System
Authors: Zhu Jiang , Cao Wen Wen
Published: October 2011

Condition Monitoring Agent (referred to as CMA) inherits and develops the concept of "concentrator" and "monitoring station", and play a connective role in the condition monitoring field of power transmission and transformation system. This paper describes the various concepts associated with the CMA and the CMA's design principles, general requirements and functional design.
Measurement Based on the "Group Linear Regression Method" of Harmonic Impedance
Authors: Wang Lei , Guo Su Feng
Published: October 2011

Harmonic pollution monitoring and control is the key to an accurate estimate of harmonic impedance, and thus an accurate assessment of public connection points of the harmonic emission level. This paper analyzes the link under the star-shaped and triangular three-phase asymmetrical power systems derived established a three-phase unbalanced power system harmonic impedance matrix estimation model. Model is based on a large number of systems and load the public connection point of the simulation data, the real and imaginary part of the harmonic impedance by opening and using grouping multiple linear regression method, on the system side harmonic impedance matrix to estimate the value of each element. Simulation and error analysis shows that the model obtained is more accurate and effective.
Comprehensive Evaluation of Power Transmission and Transformation Project Based on Improved Radar Chart
Authors: Wang Yan Ling , Li Yan Jun
Published: October 2011

General evaluation methods applied in comprehensive evaluation of transmission and transformation project are slightly insufficient in terms of considering index coordination, and radar chart can solve this problem. For the shortcomings of traditional radar chart, AHP and entropy weight are combined to get comprehensive weight which is converted into angle to reflect the influence degree of indexes to evaluation objects; angle bisector is introduced as index axis and the eigenvector is extracted to get the unique evaluation result. On the basis of stage evaluation, an index system of comprehensive evaluation based on project implementation effect and management level is established. By applying improved radar chart, the comprehensive evaluation of three voltage levels actual projects shows the practicality of established index system, and validates the feasibility and effectiveness of improved radar chart.
The Research on Power System Design and Calculation Visualization in Mine
Authors: Jin Bao Quan , Wang Yan Kun , Wang Jun Fei
Published: October 2011

For the complexity of power supply system design and calculation process in mine, a visual approach is presented.The integrated program with power mapping, analysis alculation and document management platform, the advanced visual programming technology, activex automation technology, object-oriented design methods are used with the secondary development using its built-in vba on the autocad platform.The entire system is divide into drawing and design calculation and output module with modular theory, the database is used as core for combining into a unified and organic whole by associating primitive objects and data. Studies show that the method can quickly and accurately complete the power supply design, it is important for power supply safety in mine.
A Comparison of Short-Circuit Current Decaying Calculation between PSS/E BKDY and Computational Curve
Authors: Ding Zhi Gang , Ge Jing Tian , Cao Wei , Qi Xiao Qing , Yang Wen Qing
Published: October 2011

The calculations of short-circuit current decrement with PSS/E BKDY and computational curve were compared with the one by the dynamic simulation of PSS/E. Calculation shows that the accuracy of the result by PSS/E BKDY is quite good while the one by computational curve is so conservative that it makes larger errors. The reasons for the above results have been analyzed theoretically.
The Research of Wind-Light Complementary Based on Pumped Storage Power System
Authors: Li Yan Qing , Yang Man Man , Zhao Liang , Wang Fu Ju
Published: October 2011

The wind-light complementary based on pumped storage power system makes use of wind energy, solar energy and their complementary in time and area to generate clean power, and utilizes pumped storage to realize energy storage and backup power supply, which has broad development prospects. The paper begins with the necessity of making use of wind energy and solar energy, then introduces the structure characteristics, working principle, feasibility and advantages of the wind-light complementary based on pumped storage power system, and presents the system’s matching calculations.
Method of Safety Assessment about the Electric Power Supply Company Based on Cloud Gravity Center Theory
Authors: Ma Li Yun , Shi Quan Sheng
Published: October 2011

Since there are lots of qualitative indexes on safety assessment of the electric power supply company, the issue becomes exigent as how to transform qualitative descriptions to quantitative indication to make the safety assessment more scientific and accurate. Cloud theory which is based on traditional fuzzy set theory and probability theory consider the fuzziness and randomness, providing a powerful method for qualitative and quantitative information combining. This paper introduces Cloud gravity center evaluation in Cloud theory to safety assessment of the electric power supply company, which renders the reasonable transformation from qualitative concepts to quantitative descriptions. The case analysis shows the method is verified and scientific.
Optimization and Application of Bearing Support for Output Shaft of C-EPS
Authors: Chen Zhi Gang , Fu Wei , Zhou Ting Ming , Li Meng Qi , Liu Zhi Hui , Tang Ning
Published: October 2011

In order to obtain the optimal situation of the output shaft load in different bearing support system, this paper has established output shaft load calculation model in one bearing, double bearings and three bearings support system to compare the calculation results. Use equivalent output shaft to do theoretical calculation and use finite element method to calculate the strength and stiffness of the uniform output shaft for comparison among three types of support. The results shows that stress value of output shaft with theoretical calculation is closed to the value with finite element method, but reverse as the deformation of output shaft, and the optimization values are less than 1% with three supporting bearings.
Sine Function and Power Function Model with Photovoltaic Generation System in Simple Installation
Authors: Muraoka Masumi , Masuda Ryosuke
Published: October 2011

This paper shows the result of analytical consideration of the optimality of the solar panel installation for the simple photovoltaic generation system. The power generation is efficiency when the angle of solar panel is to change angle finite times. We adopted the approximated function to figured air mass with sine function or power function in solar radiation data, and calculated the solar radiation to decide optimum angle analytically. Then we have obtained the optimal relation which means the optimal relative angle, and the solar power generation will be made efficiently by using only simple structure.
Applications of Electromagnetic Methods in Selecting Ground Sites for Ultra High Voltage Power Plant
Authors: Tang Xin Gong , Xie Xing Bing , Chen Qing Li
Published: October 2011

We present a combined electromagnetic method which consist of Audio Magnetotellurics (AMT) and Transient Electromagnetic method (TEM) to the utilize in the selecting sites for ultra high voltage power plant. The inversion profile gives the underground resistivity distribution for the power engineers to select proper ground site location. The result is satisfactory and some ground sites have been established already, indicating that electromagnetic method is suitable for selecting the ground site for ultra high voltage power plant.
Measurements and Classifications of PD Pulse on HDPE Specimens during Degradation
Authors: Zhang Zhou Sheng , Xu Yi Xun , Ma Ai Qing
Published: October 2011

Discharge may take place in high voltage apparatuses in the form of void discharge, corona discharge and surface discharge. Understanding of the discharge is very important to know the condition of the insulation. Partial discharge (PD) current pulse waveforms contain essentially all the available information concerning the PD generation and thus the available information concerning the physical mechanism of degradation and breakdown of insulation. In this paper, three types of discharge model for polyethelene insulation material are constructed and the PD current pulse waveforms are extracted from experiments. In order to obtain pulse waveform characteristics, the extracted pulse waveforms are pre-selected and normalized, and then a Sampling Counting Ratio (SCR) classification technique is investigated to reveal the multi-peak and oscillation information about the PD current pulse waveforms. Results show that the classification would enable us to estimate the progress and degree of the degradation.
Parameter Calculation of Brushless Doubly-Fed Machine Based on the Genetic Algorithm
Authors: Xiong Fei , Wang Xue Fan
Published: October 2011

Because of special structure for the Brushless Doubly-Fed Machine (BDFM) and complex magnetic field coupling of different pole pairs, general parameter calculation and experiment methods are not accurate and fit for the BDFM. A parameter calculation method of the equivalent circuit for the BDFM based on the genetic algorithm (GA) is presented in this paper. The parameters of the equivalent circuit are considered as a group of unknown variables to solve the mathematical equation in different operating conditions. The difference between calculated and measured values is taken as a target function to be minimized through optimizing the parameters of the equivalent circuit by using the GA. The calculated results show that the method is valid to solve the related problems and it is suitable to be applied in the parameter calculation for the BDFM.
Theoretical and Experimental Results of DC and AC Magnetic Flux Transformation Using HTS Superconducting Closed Loop
Authors: Kósa Janos
Published: October 2011

This paper presents the results of my experiments that may open a new path for advanced applications by using continuous closed superconducting YBCO loops. I examined a novel arrangement of a perfectly closed superconducting loop made of HTS wire in DC and AC flux transformer. I designed a self-limiting transformer with this solution. At the same time I also tested the operation of the continuous YBCO loop developed with my own technology. In the first experiment I used YBCO superconducting rings made from a bulk. Later I used superconducting wire. I could carry out these experiments because earlier I had elaborated the machining of the YBCO bulk and wire.
Research on Standard Device for Power Frequency Lines Parameters Tester Based on the Technology of Virtual Complex Impedance
Authors: Zhang Jun , Lei Min , Wang Si Qi , Qi Cong , Xu Chen
Published: October 2011

The topic research, standard device for power frequency lines parameters tester, can be used for calibrating the power frequency lines parameters tester. The equip functions involve: positive/zero sequence impedance, positive/zero sequence capacitance, etc. The topic introduces the working principle and composition of the standard device, focusing on the technology of virtual complex impedance and accurately amplitude control. The paper end gives the relevant specification and experimental data. The research of the standard device can be used to resolve the traceability of power frequency lines parameters tester.
Two-Dimension Fault Line Selection Method Based on Transient Signal Features of Fault Phase
Authors: Zhang Wen Hai , Yang Jian Wen , Xiao Xian Yong , Wang Ying
Published: October 2011

When single-line-to-ground fault happen in neutral non-effectively earthed system, there is a big difference between the fault feeder and un-fault feeder in transient signal energy centralized frequency band and signal amplitude of fault phase. The transient signal energy in fault feeder’s fault phase is bigger, and it centralizes in lower frequency band. But the transient signal in un-fault feeders’ has the contrary features. And this feature is affected little by the fault initial angle. So the paper proposed a method that using the gravity frequency and transient signal energy to form a two-dimension line selection method that using the signal overall distribution characteristics. It can be applied in neutral unearthed and resonant system simultaneously. And the method is effectively to different fault initial angle and fault resistance. The method is proved correctly, effectively and adaptively by actual simulation in different fault cases.
Investigation on a Novel Four-Quadrant Power Electronic Transformer
Authors: Ma Hong Xing , Li Hua Wu , Yang Xi Jun
Published: October 2011

Power Electronic Transformer (PET) has potential application value in distribution network. This paper presents a novel PET with only one stage single-phase to single-phase AC/AC converter at the primary side of the transformer, the high voltage end, which generates high-frequency alternating voltage. The secondary side of the transformer, the low voltage end, is also one stage AC/AC converter, by which low power frequency voltage can be created. The final stage is a resistive converter obtaining low DC output voltage and unitary input power factor. Consequently, the unitary power factor can be reflected to the mains side and the PET owns a four-quadrant operation capability. The theory of four-quadrant PET is analyzed and the simulation analysis using MATLAB/SIMULINK is also provided. The result shows that this kind of PET holds some prominent advantages such as simple structure, easy to control, safe commutation, unitary input power factor, bidirectional power flow and easy to cascade. So it has application value.
Analysis on Performances of Matrix Rectifier under Abnormal Conditions
Authors: Liu Xiao , Zhang Qing Fan , Hou Dian Li
Published: October 2011

Matrix rectifier (AC-DC MC) is a four-quadrant AC-DC power converter device with compact topology. This paper concerns the influence of abnormal power supply conditions to the matrix rectifier. The input and output performances of matrix rectifier with pure sinusoidal supply voltages are discussed. The input currents are symmetrical sinusoidal without any low-order components. But due to the absence of DC capacitors, the abnormal conditions at input side affect the input and output performances directly, which introduce ripples into the DC output and cause the distortion of input currents. In this paper, the low-order harmonic components in input currents, and ripples at output side are theoretically analyzed under conditions that the input voltages are unbalanced and non-sinusoidal respectively. The simulation research is carried out to verify the theoretical analysis, and the results, which demonstrated the analysis conclusions, are given.
Single Stage Push-Pull Forward Inverter of PV Power Source
Authors: Mu Xian Min , Liu Feng Chun , Li Guan Lin , Chen Xi You
Published: October 2011

This paper proposed a single stage inverter for PhotoVoltaic(PV). The inverter is a push-pull forward converter employed synchronous rectifier technique. The push-pull forward converter is used to convert the photovoltaic battery output voltage into high frequency SPWM square wave, and the rectifier circuit is used to change the polarity of the isolation high frequency transformer output SPWM wave. For improve performance of the inverter in both the command tracking and the load disturbance regulation, a PID control strategy is realized by using the TMS320LF28335 DSP. Theoretical analysis and experimental results indicate that the proposed topology and control scheme are promising for the applications of PV power supply.
The Research of Current Ripple on Interleaving Parallel High-Frequency Rectifier
Authors: Shan Hong Tao , Cai Yuan Ling , Zhang Yu
Published: October 2011

Interleaving Parallel is the unique technology with the combination of SPWM modulation technology with multiple technology. This paper was researched the interleaving parallel rectifier technology in restraining the AC side current ripple in detail, and compared current ripple in the AC side between the single rectifier and the interleaving parallel rectifier. The research was deduced that current ripple in the AC side of the interleaving parallel rectifier was lessened than the same parameters of the single rectifier. The relevant simulations were verified the characteristic of restraining the current ripple in the AC side in interleaving High-Frequency rectifier was effective.
Experimental Study on Internal Flow Field of Wet Desulphurization Tower
Authors: Zhu Jing , Xu Qi , Zhang Li Ping
Published: October 2011

In order to study the flue gas velocity distribution and pressure drop characteristics inside wet desulfurization Tower, experimental study has been carried out. Flow model is built with geometric scale of 1 / 12 , flue gas velocity ratio of 1 / 1 and different gas entrance angle as 12°and 7°. Experiment result shows that Spray liquid droplets made gas more evenly; The evenness of gas velocity distribution is very poor with very low gas load (<35%);The pressure drop in tower increases with increase of sprayer and increases with increase of gas load; The evenness of gas velocity distribution becomes poor and the pressure drop increases when gas inlet angle changes from 12°to 7°.
Wind Power System Based on Multilevel Matrix Converter
Authors: Li Li Juan , Guo You Gui , Zeng Ping
Published: October 2011

A complete direct-driving wind power system consisting of wind turbine, permanent-magnet synchronous generator, multilevel matrix converter with voltage space vector modulation strategy is proposed in this paper. The simulation model is set up through Matlab/Simulink, and the results have verified the control strategy is feasible. Multilevel matrix converters are suitable for high- voltage application of wind power generation system, and it has laid a good basis for the real system development.
Investigation about Thermal Shock Property of Plasma-Spraying Sm2Zr2O7 Thermal Barrier Coatings with Different Substrate Condictions
Authors: Zhang Hong Song , Sun Hong Chan
Published: October 2011

Effect of substrate conditions, including material type, thickness and radius of substrate, on thermal-shocking stresses of plasma spraying Sm2Zr2O7/ NiCrCoAlY TBCs was analyzed through finite element method. Results show that radial stresses decrease with time increasing, and they decrease with the increasing of distance from center to edge along radius. However, axial residual stresses increse abruptly at the edge of specimen. All residual stresses increse with incresing of thermal expansion coefficient of substrate. Radial stresses increase with substrate thickness increasing, however, they are not effectd by substrate thickness if it is great than 20mm.and axial residual stresses and shear stresses are not effected by the substrate thickness. The maximum values of axial stresses and shear stresses were not effected by sustrate radius. and values of radial stresses remian invariable when substrate radius is over 18mm.
Experimental Research on Resistance and Heat Transfer Properties of Corrugated Plate Air-Cooled Heat Exchanger
Authors: Huang Xiao Qing , Zhang Xu , Li Chun Guang
Published: October 2011

Experimental research on resistance and heat transfer properties of corrugated plate air-cooled heat exchanger under the condition of variable air and hot water flow rates has been conducted. The pressure drop and convection heat transfer coefficient correlation expressions both the air side and hot water side are acquired, where the Reynolds number for air side ranges from 401 to 6602 and the Reynolds number for water side ranges from 2536 to 19301 are adaptable.
Evaluating on Effect of HVAC Series with Impulse Excitation Voltage on Porcelain Insulator by Using Rotating Wheel Dip Test
Authors: Banhthasit Bounthanh , Tonmitr Kittipong , Kaewrawang Arkom , Suksri Amnart
Published: October 2011

This paper presents the effect of over-voltage damage on contamination surface of porcelain insulator due to impulse high voltage connects in series with high voltage alternating current (HVAC) which studied by using rotating wheel dip test. This method is artificially accelerated ageing at short period and mostly resemble real application of insulator. To evaluate this effect, the frequency of leakage current (LC) waveform has been analyzed by fast Fourier transform. The results of the experiment showed that effect of HVAC series with impulse excitation voltage created a LC like as transient state which it is highest amplitude peak values of LC flow on the specimen surface. The partial discharge on specimen surface suddenly occurs after excite by both excitation voltage at few number of cycles and increasing depends on number of cycles.
Experimental Research on the Performance of the Entrainment Jet Clean-up System Based on PIV Technology
Authors: Bai Ting He , Yu Jian Ping , Yu Shu Rong
Published: October 2011

A new clean-up technology for sedimentation basins is proposed in this paper adopting the stir-separation principle in which a clean-up bench for the analog sedimentation basin is designed according to the similarity principle and the flow field inside the tank is studied with the PIV experimental method. The results indicate that the mixture coefficient of the jet is 0.7 under different jet pressures, the fluid boundary sprayed from the combining tube of the jet is a straight line, the angle of the jet outflow is the same as that of the jet and the flow velocity of water is less than 0.1m/s in the area more than 1m away from the spouting tube. Meanwhile, the axial velocities of the jet from the jet at different Res are also measured and the semi-empirical formula is regressed.
Numerical Study of Joint Magnetisztion and Gravitational Convection of Air in a Square Enclosure under Quadrupole Magnetic Field
Authors: Jiang Chang Wei , Shi Er , Zhu Xian Feng , Zhou Zhen
Published: October 2011

Numerical computations were carried out for theromagnetic convection of air in a square enclosure under both magnetising and gravitational fields. Scalar magnetic potential method was used to calculate magnetic field. The governing equations in primitive variables were discretized by the finite-volume method and solved by the SIMPLE algorithm. The flow and temperature fields for the air natural convection were presented and the local and mean Nusselt numbers on the walls were calculated and compared. The results show that the magnetic force has significant effect on the flow field and heat transfer in a square enclosure, the average Nusselt number respects the trend of decrease first and then increase when the magnetic force number increases.
Predicting Ash Fusibility of Coal from Coal Properties
Authors: Yang Jian Guo , Zhang Xiao Long , Zhao Hong
Published: October 2011

It is significant for safe operation and energy saving to foreknow ash fusibility of coal. Ash fusibility of coal was divided into three levels according to softening temperature. The fusibility level was correlated with coal properties by a nonlinear classified model which was built using support vector machine. The model receives coal properties as input variables and would give a judgment of fusibility level as an output. Validation of the nonlinear classified model on 62 training samples yielded 100% accuracy. The prediction accuracy of 15 testing samples was 86.7%. Results indicate that the level of ash fusibility can be accurately predicted from coal properties with the nonlinear classified model.
Experiment and Thermodynamic Analysis on Mineral Formation of Cement Clinker Cogeneration from Coal in Pulverized Coal Combustion Boiler
Authors: Jiao You Zhou , Shi Zheng Lun
Published: October 2011

Take Changguang high-sulfur coal as experimental coal type; carry out the experiment of mineral formation rule of co-generation cement clicker on two-section multiphase reaction test stand and conduct XRD, SEM and EDS analyses on the mineral composition of the obtained co-generation clicker sample. It can be found from the experimental results that the mineral composition of co-generation clinker presents great difference with the temperature change in the furnace on the test stand; when the temperature in the furnace reaches to 1,330°C, the main mineral species in co-generation clinker sample are 2CaO•SiO2, Q phase and 3CaO•3Al2O3•CaSO4with excellent hydration activity. Conducted thermodynamic calculation on the mineral formation reaction probably occurring in the chemical compositions of Q-phase cement clinker co-generated from Changguang coal. It is shown in the findings of computational analyses that, according to the chemical composition of clinker, the direct synthesis reaction of 2CaO•Al2O3•SiO2firstly occurs, followed by the direct synthesis reaction of 2CaO•SiO2, the next is the indirect synthesis reaction of Q-phase mineral, and the last is the indirect synthetic reaction of 3CaO•3Al2O3•CaSO4; the final main mineral compositions of co-generation clinker should be 2CaO•SiO2, Q phase and 3CaO•3Al2O3•CaSO4. The conclusion of thermodynamic analyses on co-generation clicker mineral formation reaction basically conforms to the mineral composition in experiment of Changguang coal co-generating Q-phase cement clinker.
Technical and Economic Evaluation on Overall Condition of Circular-Cooler Waste Heat Power Station
Authors: Zhao Bin , Zhang Yu Zhu , Zhang Wei Ran , Cui Jian
Published: October 2011

The management decision fault during prophase demonstration, design and operation on power station can be avoided effectively by technical and economic evaluation of power station project. In this paper, the sintering circular-cooler waste heat power station in WISCO is taken as an example. Through analyzing the two methods of technical and economic evaluation on power plant and constructing the evaluation system of sintering waste heat power plant, the technical evaluation on overallcondition of power plant is made by adopting the ways of contrastive analysis, and index weight value of power plant is computed by analytic hierarchy process, then power station is evaluated through combining the two evaluation methods. And the bandwidth of net power output basic parameters of per ton of sinter waste heat is determined. The study results can provide reference basis for the initiating project and technology decisions of waste heat power station.
Effect of Substrate Conditions on Residual Stresses of Plasma-Spraying YSZ / Sm2Zr2O7 Thermal Barrier Coatings
Authors: Zhang Hong Song , Wei Yuan , Yang Shu Sen
Published: October 2011

Effect of substrate conditions, including material type, thickness and radius of substrate, on residual stresses of plasma spraying YSZ / Sm2Zr2O7TBCs was analyzed through finite element method in this paper. Results show that all residual stresses increse with incresing of thermal expansion coefficient of substrate.Substrate thickness has slight effect on radial residual stress, and it has no effect on axial residual stress and shear stress. Effect of substrate radius on radial stresses can be almost neglected when it is over 18mm. Effect of substrate radius on axial stresses can also be ignored.
Influence of Preheated Air Temperature on High Temperature Air Combustion in Furnace with Swirling Burner: a Modeling Study
Authors: Su Ya Xin , Wang Wen Hui
Published: October 2011

The high temperature air combustion performance of natural gas in an industrial furnace with a swirling burner was numerically modeled. A Beta function PDF (Probability Density Function) combustion model was selected to simulate the gas combustion combined with the Reynolds Stress Model (RSM) to simulate the turbulent flow. The radiation was simulated by a Discrete Ordinates method. The NO chemistry was simulated by thermal NO model. The simulation was performed at inlet air oxygen fraction 8% and the total air excess ratio 1.1 for natural gas. The effect of preheated air temperature on NO emission, temperature, O2 and CO distribution in the furnace was investigated. Results showed that thermal NO emission increased when the preheated air temperature increased from 1073 K to 1473K. When the preheated air temperature increased, both of the maximum and averaged temperature in the furnace increased. The oxygen was consumed by the formation of thermal NO at higher inlet air temperature and the fuel was not fully burnt out.
Study on Reasons of Frequent Outfire in a Boiler with Horizontal Concentrated Burners
Authors: Lin Shu Biao , Cai Xin Chun , Jin Yan
Published: October 2011

This paper discusses the problems of instable combustion, serious slag, outfire in boilers with horizontal concentrated boiler, taking a 410t/h boiler as the sample. Through experimental researches on different adjusting characteristics of horizontal concentrated burners, it is found that the coal air mixture has different characteristics in velocity and concentration when the baffles are respectively left in the centrifugal or centripetal side of the bent pipes, and that the baffles wear pattern also depends on individual installation location. During many cold and hot commissioning tests, the effective height of baffles is regulated and the original refractory belts are replaced to vertical evenly spaced bare-tube wall. After taking the above measures, the significant problems in the boiler are settled and the economics and safety operation performance is improved considerably. Thus the paper can offer certain references for other boilers with horizontal concentrated burners.
Combustion and Heat Transfer in 300MW Oxy-Fired CFBB
Authors: Wang Chun Bo , Ma Xiao Fei , Zhang Jiao , Sheng Jin Gui , Li Hong Wei
Published: October 2011

A combustion and heat transfer model in oxy-fired CFBB was set. Particle diameter, voidage of the bed ,etc, was analyzed with 30%, 50%, and 70% oxygen. Take a 300MW CFBB for example, the heat transfer characteristics in furnace were numerical simulated. In the sparse zone, heat transfer coefficient is proportional to oxygen concentration at the same voidage of the bed; under the same operation condition, the heat transfer coefficient in CFB increases with the voidage of the bed at first, then it decreases. It was found the heat transfer capability decrease due to the higher concentration of oxygen. It is necessary to set an external heat exchanger to keep a normal combustion
Surface Tension and Bubbles
Authors: Xu Cai Xia , Tang Hai Rong
Published: October 2011

From a molecular perspective, we described the origin of surface tension. Surface tension is exceptionally good at rounding things out, such as bubbles can produce in surfactant solution , also in liquid or vapor-liquid phase transition. Through the experiment of determination of saturated vapor pressure of pure liquids, maybe we can conclude that almost all the bubbles were generated as result of the breakup of the gas-liquid interface.
Optimizing Design of Direct Air-Cooled Condenser
Authors: Wang Xue Dong , Zheng Yan Juan , Luan Tao
Published: October 2011

The optimizing design approach of direct air-cooled system was described in detail in this paper. Based on the approach, the wind speed, ambient temperature and heat transfer area of air-cooled condenser were considered to meet the design parameters and the rated power. The optimizing results and economic analysis were discussed.
Dynamics Simulation of the Crank and Connecting Rod Mechanism of Diesel Engine
Authors: Luo Qing Guo , Wang Xu Dong , Gong Zheng Bo , Wang Feng
Published: October 2011

Based on the virtual prototyping technology and flexible multibody system dynamic theory, the author founded the rigid-flexible coupling multibody dynamic analysis model of the crank and connecting rod mechanism of diesel engine, combining the means of 3D solid modeling, finite element analysis and multi-body dynamic simulation. Through the simulation, the dynamic loads in the working cycle of the mechanism are obtained, which provides reference for dynamic stress and fatigue analysis of the mechanism.
Research on Stress Field of the Steam Turbine Rotor Based on SVM and the Finite Element Analysis
Authors: Wang Jun Yu , Ji Dong Mei , Yao Xiu Ping , Shi Jin Yuan , Yang Yu
Published: October 2011

A model for on-line calculation of equivalent stresses in steam turbine rotors has been built up based on Support Vector Machine (SVM) neural network and the finite element method. Regarding 125MW steam turbine rotor as an object, SVM method is employed as a tool to train large numbers of date about the equivalent stress of the rotor, which obtained from the finite element method. A model can be gotten after finishing training the data. Equivalent stresses of rotor obtained with finite element and SVM model are compared during cold start. Results show that similar calculation results of equivalent stress may be obtained with either finite element or SVM model. However, with the latter one, the calculation becomes easier and fast, which is applicable for on-line calculation of equivalent stresses in turbine rotors, and may serve as a reference for on-line life management of turbine rotors.
Analytical Solution of Slip Flow of Nanofluids over a Permeable Wedge in the Presence of Magnetic ﬁeld
Authors: Niu Jia Jia , Zheng Lian Cun , Zhang Xin Xin , Li Chun Rui
Published: October 2011

In this paper, a boundary layer analysis is presented for the slip flow of three types of incompressible viscous nanofluids past a permeable wedge in the presence of a magnetic field. Due to the appearance of a slip boundary condition at the surface, local similarity solution of the reduced nonlinear ordinary differential equation is obtained by the HAM coupled with minimizing the square residual error. The effects of pertinent parameters, such as the magnetic parameter, the solid volume fraction of nanoparticles, the slip parameter and the type of nanofluid on the flow, are analyzed and studied in details. It is found that Ag-water has the highest skin friction coefficient at the surface compared with the others.
Research on Combustion Characteristics and Emissions of Methanol-Diesel Fuel with Different Additives
Authors: Zhang Cui Ping , Zhai Xu Mao , Li Yu Juan , Sun Zhi Gang
Published: October 2011

Methanol and diesel are almost not soluble, which greatly limits the further study and popularization of the methanol-diesel fuel. To study the emission and combustion characteristics, the 4100 turbocharged and intercooled diesel engine was fueled with 0# diesel and M10 with different additives in the experiment. The result shows that, the maximum cylinder pressure and the peak of the heat release rate in the initial stage of combustion for M10 with iso-octanol and isooctyl nitrate as additive are higher than that of diesel, while the soot emission is lower and NOx emission is slightly higher than diesel’. The maximum cylinder pressure and the heat-release peak in the initial stage of combustion for M10 with dimethyl ether as additive are both lower than diesel’, and the NOx and soot emissions are obviously decreased. The power of the two blend fuels is lower than that of diesel but the magnitude is small, meanwhile the HC emission is slightly increased, while the CO emission is little declined.
Modeling and Simulation of Marine Diesel Propulsion System in Ship Maneuvering Condition
Authors: Wang Hai Yan , Tang Hui Yan , Sun Jian Hui
Published: October 2011

To study all-regime performance of marine diesel propulsion system in ship maneuvering, an all-regime model for diesel propulsion system is established, including starting, braking, reversing, etc. The dynamic simulation models of propeller running across four quadrants and ship longitudinal motion are given too. A 76000DWT bulk carrier is selected as plant. The simulation results show that steady data of diesel are in good accordance with test-bed data, and dynamic data match to ship sea trial data in crash stop condition. The model is accurate and effective.
Simulation of Urea-SCR Catalytic Converter for Diesel Engine
Authors: Wang Qian , Han Xiao Jing , Qi Ping , Wang Jing
Published: October 2011

A three-dimensional model of a diesel Urea-SCR（Selective Catalytic Reduction）catalytic converter system was set up with aid of CFD software AVL FIRE coupled with available knowledge of SCR chemical reaction kinetics. Basing on the validation of the spray injection model of Urea-water-solution, the numerical simulation was made to get the distribution of pressure, velocity, temperature and species concentration in the converter and NOxconversion in different conditions by considering the injection and evaporation of the urea-water-solution, the thermal decomposition and hydrolysis into ammonia and the surface catalytic reactions in the monolith. The simulated results have some reference meaning for improving NOxconversion efficiency and optimizing the diesel SCR catalytic converter.
Research on Emulsified Fuel Applied to Engine YC6J190
Authors: Xiong Shu Sheng , Ren Xiao Shuai , Xie Lian , Wang Ting , Li Wei , Wu Xi Jiang , Yao Hong , Hou Ming Yang , Xu Jin
Published: October 2011

The research is conducted on emulsified fuel applied to engine YC6J190 without any modification of the engine. In this experiment, the contrast of the fuel consumption and the emissions is studied with having water or not. From the results, it can be concluded that the emulsified fuel can reduce the NOx and smoke emissions greatly at the same time, but the fuel consumption is different in different conditions. The emulsified fuel with 20% water is most suitable for this type of engine regarding fuel consumption and emissions. Then dynamic characteristics is tested using the emulsified fuel with 20% water to find that the decline in power and torque output is not apparent. At the end, we conclude that emulsion containing 20% of water would replace diesel as for this type of engine.
Research on Effect of Nozzle Structure Parameters on Performance of Common Rail Diesel Engine
Authors: Luo Zi Lai , Chang Han Bao , Shao Li Min
Published: October 2011

Structure parameters of diesel engine spray system have decisive effects on its performance. The paper studies the effects of 8 sets of nozzles with different structure parameters on performance of diesel engine with the purpose to realize high-efficiency, low-emission and low-noise combustion process in diesel engine, based on requirements and characteristics of performance optimization of DI diesel engine, thus realizing optimum design of nozzle structure parameters for high pressure common rail diesel engine.
Cutting Stiffness Analysis of a Gearbox’s Back Case Based on FEA
Authors: Dai Xi Liang , Peng Sheng Hui , Wang Yuan
Published: October 2011

For the stiffness of the cutting face is nonuniform, the evenness of the machining face may not be ensured during a gearbox back shell’s cutting process. By reasonably simplifying the machining process, a cutting stiffness contrast analysis of three design schemes is performed in this paper, and then improvement advice is brought forward to the design engineer. The paper has some engineering value and can be used for reference in similar analysis.
Lattice BGK Study on Flow Pattern in Two-Dimensional Wall-Driven Semi-Circular Cavity
Authors: Yang Fan , Liu Lian Guo , Shi Xu Ming , Guo Xue Yan
Published: October 2011

The flow pattern in a two-dimensional wall-driven semi-circular cavity is analyzed using the lattice Boltzmann method (LBM). The treatment of curved boundary with second-order accuracy is used. The streamline contours as well as dimensionless velocity component along the central line of a semi-circular cavity are obtained for different Reynolds numbers. The numerical results show that the LBM can capture the formation of primary, secondary and tertiary vortices exactly as the Reynolds number increases and has a great agreement with those of current literatures.