Table of Content

31 January 2014, Volume 47 Issue 1

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Orginal Article

Research on Untwisted Strand of Overhead Transmission Lines Based on Digital Image Processing Method

YANG Zhi-yong, WANG Wei, SU Fan, WU Gong-ping, BAI Yu-cheng, YAN Yu

2014, 47(1):  1-7.  DOI: 10.11930/j.issn.1004-9649.2014.1.1.6

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Due to the stringing construction damage and the long-term effects of the external environment, untwisted strands and even broken strands are prone to occur in overhead transmission lines. Timely diagnosis and overhaul of the defects are therefore very significant for the power grid security. Inspection by robot equipped with visual detection devices is an effective method in modern condition-based maintenance of power transmission lines. On the basis of analyzing the constraints and the distribution of transmission line textures, an untwisted strand judging model is built based on the texture slope distribution and an automatic diagnosis method of the untwisted strands of overhead transmission lines is proposed based on digital image processing. This method gives the results of image diagnosis by using the judging model after calculating the texture characteristic distribution of the transmission lines which are extracted from the image taken by the robot. Experiment shows that this method can quickly detect the fault information of the untwisted strands, and satisfy the real-time requirement of online inspection.

Research on the Image Feature Extraction Method for Laser Detection of SF₆ Gas Leakage

GENG Jiang-hai, WANG Ping, TIAN Shan

2014, 47(1):  8-12.  DOI: 10.11930/j.issn.1004-9649.2014.1.8.4

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In order to realize the effective management of detection information, a management system for laser imaging detection of SF₆ gas leakage is developed with Matlab language in this paper, which can automatically achieve image enhancement, wavelet threshold denoising and frame differencing and has the function of visual display of leakage movement trajectory, leakage locating and quantification, as a result, realizing the change from artificial recognition to automatic recognition and improving the diagnosis accuracy and automation level. This system can be used for assistant evaluation of the insulating status of the SF₆ apparatus and provide technical reference for fault diagnosis for maintenance personnel. Its effectiveness has been proved in practical use.

Electric Ice-Melting Technology of High Voltage Transmission Lines

LV Xi-feng, HE Qing

2014, 47(1):  17-22.  DOI: 10.11930/j.issn.1004-9649.2014.1.17.5

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High voltage transmission line icing has a serious threat to the safe operation of power grids, electric ice melting is a complex multi-physics nonlinear process. This paper reveals the mechanism of ice melting in theory by full method, analyzes the ice melting time of LGJ-70/10 and LGJ-400/65 type wires under different boundary conditions, and proposes the important parameters of ice melting in shortest time which is related to the ice melting efficiency, the security of transmission lines and energy saving needed to consider in the field of electric melting technology, summarizes the influence of the ice thickness, ice temperature, the conductor temperature, environment temperature, and convection load on the shortest ice melting time, which will provide a reliable theoretic basis for ice melting technology of high voltage transmission lines.

Research on Electric Unbalance Degree of 500 kV Four Circuits on the Same Tower

MA Min-hua, WANG Jing-yi, LI Zhi-tai, PAN Chun-ping

2014, 47(1):  23-27.  DOI: 10.11930/j.issn.1004-9649.2014.1.23.4

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In order to increase transmission capacity of electric power corridor significantly, multi-circuit on the same tower was constructed more and more widely in developed area. However, it’s difficult to realize transposition for multi-circuit on the same tower because of complex conductors arrangement, and electric unbalance degree of the transmission lines would get worse if phases were arranged inappropriately. ATP-EMTP and Matlab programs were applied to electric unbalance degree calculation for the three-layer and six-layer cross-arms tower of 500 kV four circuits on the same tower. According to the comparison of negative sequence voltage and current, lightning trip-out rate and electromagnetic environment, better electric unbalance degree was achieved when commendatory phase arrangement was adopted on three-layer cross-arms tower and diverse phase sequence was chosen on six-layer cross-arms tower. The results also showed that induce voltage and induced current from energized circuits got high when single circuit was maintained. It should be paid much attention to isolated switches selection.

Research on the Windage Yaw Calculation of UHV Long Insulator String

MIN Xuan, WEN Zhi-ke, WU Xiang-dong, SHAO Gui-wei, JI Kun, CAI Huan-qing

2014, 47(1):  28-34.  DOI: 10.11930/j.issn.1004-9649.2014.1.28.6

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Calculation of windage yaw angle of transmission lines is usually made by rigid body statics model. In order to simplify the calculation process, it is supposed in this model that the insulator string and conductor are rigid body, and no bending or deformation occur for the insulator string when wind blows. For the UHV transmission line, however, the chain structure bending extent of the UHV insulator string is higher than that of lower voltage transmission lines when wind blows because of its longer insulator string. It is therefore imperative to study the effects of long insulator string on the windage yaw angle of transmission lines. Numerical simulation and simulation verification test of windage yaw shows that when rod insulator string is used for UHV transmission lines, the effects of the chain structure bending can be ignored; but for the disk insulator string, when the adjacent conductor hanging points are higher than the insulator string itself, the effects shall be taken into consideration, i.e., the horizontal displacement of insulator string calculated by the existing method shall be added by the deviation value caused by chain structure bend of insulator string, otherwise the windage yaw fault may occur for the UHV tower head

Analysis of Zero-Sequence Current Gain Considering Nonlinearity of Line Parameters

CHEN Hao, WANG Yu-rong, ZHOU Yong-rong

2014, 47(1):  35-38.  DOI: 10.11930/j.issn.1004-9649.2014.1.35.3

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Single-phase earthing faults occur commonly in a power grid. While a single-phase earthing fault happens following the three-phase tripping in transmission line, the zero-sequence current at the later tripped side usually has a sudden change. According to the analysis of fault waveforms, the gain of zero-sequence current may be affected by the nonlinearity of line parameters to some degree. Taking into account the nonlinearity of transmission line parameters, the relationship among line parameters, fault points and zero-sequence current is analyzed quantitatively. The study results are helpful for better understanding the action of relays after faults. The simulation results verify the accuracy of the theory analysis.

Test and Simulation on Vibration Attenuation Effects of Phase-to-Phase Spacers with Damping Springs for Six-Bundle Conductors

KONG Wei, SONG Ling-feng, TONG Dan-dan, JIAN Zhe, HU Hai-peng

2014, 47(1):  44-48.  DOI: 10.11930/j.issn.1004-9649.2014.1.44.4

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Stabilized amplitude and dynamic bending strain of two-phase six-multiple conductors with new patented phase-to-phase spacers with damping springs in aeolian vibration under different wind loads, were studied. Finite element software ANSYS was used to establish the finite element model of the two-phase six-multiple conductors for numerical simulation. Research results show that by using the new phase-to-phase spacers with damping springs, the conductor system’s stabilized amplitude and dynamic bending strain under different wind loads are smaller than that with traditional phase-to-phase spacers, indicating excellent vibration attenuation and energy dissipation capability. The performance of the phase-to-phase spacers with damping springs can be changed by adjusting the spring stiffness and heavy-ball mass. Results of numerical analysis are coincident with the test results and would be quite satisfactory when LINK10, COMBIN14, MASS21 and other such units are adopted to establish the product’s finite element model.

Analysis on the Tensile Failure Modes of Carbon Fiber Composite Core Rod Used in Overhead Stranded Wires

YU Hong-yun, WANG Liang, LI Rui, YU Min-bo, QIAN Miao, LI Zhou-xuan, LI Guo-yong, ZHU Zhi-hua, YUAN Qun, DONG Xuan

2014, 47(1):  49-52.  DOI: 10.11930/j.issn.1004-9649.2014.1.49.3

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In order to ensure the safe and stable operation of power grid which uses carbon fiber composite cores in overhead conductors, and improve the performance testing technology, simulation analysis is made on the tensile failure mode of carbon fiber composite core with aid of 3D drawing and finite element software, which shows that the tensile failure occurs firstly in the carbon fiber layer, then in the glass fiber layer, and mainly in the form of delamination. The simulation result is very close to the testing result. This study results can provide technical & theoretic support for manufacturing process, testing method and engineering application of the carbon fiber composite core.

pplication Research of FRP in the Transmission Structures

YANG Lin, WANG Hu-chang, ZHAO Xue-ling

2014, 47(1):  53-56.  DOI: 10.11930/j.issn.1004-9649.2014.1.53.3

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This paper briefly introduces the applications and features of the fiber reinforced polymer(FRP) in the transmission tower, describes the connection type of composite material components. The angle steel tower, the tower-shaped crossarm composites and glass composite tower are analyzed in the technical and economic comparison. The results show that the composite tower has advantages in transmission tower and can be generalized in application.

Study on Stability of Straight Welded Steel Tube under Axial Compression Test

XING Hai-jun, HAN Jun-ke, SHI Gang, ZHANG Da-chang, LI Zhen-bao, WANG Xu-ming

2014, 47(1):  57-62.  DOI: 10.11930/j.issn.1004-9649.2014.1.57.5

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Straight seam steel pipe has been widely applied to steel tower truss structure, and the main steel grades include Q345 and Q420. With the development of metallurgical and steel processing technology, the steel’s axial bearing performance has been improved gradually. But up to now, few researches have been made on bearing test of axial steel pipes. To research the stability of straight welded steel tubes, compression tests are conducted on total 98 pieces of straight welded, un-galvanized Q345 and Q420 steel tubes with a diameter-thickness ratio in the limited range. Based on the results of experimental and simulation, their stability performance is studied and the bearing capacity is compared with its standard value so as to obtain the characteristics of deformation failure. The cross-section classification is proposed for the Q345 and Q420 with two ends hinged for designing the stability of steel angle members under axial compression. The results also provide the basic data for study of the design method of steel structures.

Analysis of Key Technology and Equipment Capacity of 500 kV Directly Changing to 110 kV

BAI Yao, HU Dan-hui, LU Fei

2014, 47(1):  63-65.  DOI: 10.11930/j.issn.1004-9649.2014.1.63.2

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This paper inquires into technical advantages,development needs and research status of 500 kV directly changing to 110 kV, and analyses the key technology and equipment capacity. Focusing on researching restricting factors of transformer capacity and manufacturing capacity, the paper calculates the single-phase autotransformer’s maximum capacity in different voltage regulating methods, and analyses the technical level and needs of switch and CT at the maximum capacity.

PSS/E-based Simulation System Design for Functional Verification on the Power Dispatching Automation System

LI Feng, ZHUANG Wei-jin, WANG Yong, ZHANG Hong, PAN Ling-ling

2014, 47(1):  66-70.  DOI: 10.11930/j.issn.1004-9649.2014.1.66.4

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The power dispatching automation system has been widely used in the power dispatching center, so it’s very urgent and important to ensure the system’s functions, performance and reliability to meet the dispatching demand through functional verification of the system. This paper presents a simulation system design, which use PSS/E software as calculation engine. The simulation system can simulate continuous operation of the power grid, and the power dispatching automation system is driven to run based on the simulated data. The case study shows that the proposed scheme is feasible and has good application prospect.

The Bifurcation Effect of Wind Farm on Voltage Stability of Power System

LU Huan-li, KANG Ji-tao, LUO Qiang

2014, 47(1):  75-80.  DOI: 10.11930/j.issn.1004-9649.2014.1.75.5

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Continuation method is used in this paper to make a single-parameter and two-parameter bifurcation analysis respectively of the wind farms of double-feed induction generators and induction generators. A formula is derived for flow computations of power systems integrated with wind farms under static var compensator(SVC) conditions, and a method is designed for tracking the two-dimension bifurcation curves. The bifurcation results are verified by time-domain simulation Reactive power compensation is an important part in wind farm. The time-domain simulation with different wind generator models and parameters indicates that the SVC affects the location of bifurcation points and voltage instability process. The greater the time constant is, the faster the voltage instability process is. For the model of dynamic induction generator wind farms, the smaller the inertia time constant time is, the faster the voltage instability process. For double-feed induction generator wind farms, the transmission limits and bifurcation values are varied with different power factors.

Study on the Dynamic Air Gap Between Stator and Rotor of the Hydro-Generators

CHEN Guang-hui, WU He-jing, ZHONG Su, LV Gui-ping, PANG Li-jun, WANG Yan, TIAN Chao

2014, 47(1):  81-85.  DOI: 10.11930/j.issn.1004-9649.2014.1.81.4

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In order to solve the problem that the working air gap of generator units is smaller than the designed air gap, it is necessary to analyze the influencing factors. Based on a comparison of the finite element analysis and the testing data of a power station, a study is made on the dynamic air gap between the stator and rotor of the hydro-generator, which shows that the simulation of the hot manipulation between rotor spider and magnetic yoke is the precondition for analyzing the air gap variation between stator and rotor gap; under transition condition, the centrifugal force produced by variable speeds, the material elastic modulus and the thermal expansion deformation of the rotor and stator have various influence on the air gap.

Time-Frequency Analysis of Shafting Torsional Vibration Caused by Asynchronous Juxtaposition

XU Jing, CHEN Dong-chao, GU Yu-jiong

2014, 47(1):  86-90.  DOI: 10.11930/j.issn.1004-9649.2014.1.86.4

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The three-dimensional finite element model can not only well describe the complex structure of the shafting system, but also accurately reflect the torsional stresses of the stress-concentrated cross sections such as the chamfer and the groove. In this paper, the shafting system of one 660-MW turbo-generator is studied, and the process of solving the torsional vibration response with ANSYS software is presented. The analysis on the response properties of the torsional vibration caused by asynchronous juxtaposition indicates that the torsional stress amplitude of each section reaches the maximum value rapidly, and then oscillates and weakens gradually. Faults are harmful to the rotor between the low-pressure cylinder and the generator. The torsional stress consists of the first two orders of natural frequencies of the torsional vibration and a small amount of power frequency components, and the proportion of the model component of different cross-sections differs from each other. Additionally, the responding characteristics of the torsional vibration are roughly similar both in 120° and 180° asynchronous juxtaposition, with the former one outweighing the latter one. The research results are helpful to improve the safety management of the unit.

Modification on Combustion System of Opposed Firing Boiler to Reduce De-Oxidation Atmosphere at Sidewalls

CHEN Min-sheng, LIAO Xiao-chun

2014, 47(1):  91-95.  DOI: 10.11930/j.issn.1004-9649.2014.1.91.4

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In order to solve the problems of the severe high-temperature corrosion and de-oxidation atmosphere that cannot be effectively reduced by combustion adjustment at the sidewalls of one 600-MW supercritical opposed firing boiler, the schemes for improving the combustion system to prevent high-temperature corrosion on the sidewalls such as installing air ports along the sidewalls and burner innovations are proposed. The numerical simulation results show that installing air ports along the sidewalls is most effective, which makes the oxidizing atmosphere be formed near the sidewalls. Practical operation after the modification demonstrates that the testing results are consistent with those of the numerical simulation; the atmosphere at the sidewalls is greatly improved and the major running parameters of the boiler meet the designed requirements. The modification can ensure the boiler operation and can be a reference for high-temperature corrosion prevention.

Analysis on Gas Turbine Tripping by Fan Fault and Modification of Gas Room Fan

LI Ming, ZHANG Shao-qing, ZHANG Yue-zhong, SUN Liang, PENG Hua

2014, 47(1):  96-99.  DOI: 10.11930/j.issn.1004-9649.2014.1.96.3

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Through the analysis on the gas turbine tripping caused by the insufficient output of the ventilation fan, the inadequate rising height of the crank arm of the fan outlet and the wrong position of the limited switch in the installation and debugging of the gas room ventilation fan(88VL) of Huadian Wujiang 2×9E Gas Turbine Project, certain simple and feasible innovative plans such as changing the installation mode of the fan external limit switch and the limit switch control wiring are proposed and implemented successfully on the Gas Turbine 1 of the project, which have speeded up the installation, made the equipment debugging more convenient and improved the security of the gas turbine. Therefore, these plans are accepted by the gas turbine manufacturer and applied in the installation and debugging of the gas turbines of the same type.

Treatment of HP-IP Rotor Bending in Domestic 660-MW Supercritical Units

ZHANG Fa-ke

2014, 47(1):  100-103.  DOI: 10.11930/j.issn.1004-9649.2014.1.100.3

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When excessive residual internal stresses exist in forging blanks of turbine rotors, bending deformation will happen with the stresses releasing as time passes after the unit is put into operation, causeing severe unit vibrations as a result. To solve the problems of the HP-IP rotor bending deformation and the followed rising vibrations of domestic 660-MW supercritical units caused by residual internal stress releasing, the casings are uncovered to analyze the vibration trends. Inner inspection and field dynamic balancing compensation measures are implemented, which have reduced the vibration to the acceptable range eventually. With the on-site experience of dealing with such faults, some suggestions are put forward to provide reference for tackling the same kind of issues.

Study on Water/Electricity Cogeneration System and Peak Shaving Operation Modes in Nuclear Plants

LI Jin, LI Chu-fu, HAN Shan-biao, LU Wei-wei, ZHANG Yan-xia

2014, 47(1):  104-107.  DOI: 10.11930/j.issn.1004-9649.2014.1.104.3

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The water/electricity cogeneration system of nuclear power plants is investigated in this paper. By coupling the nuclear power plant with large-scale reverse osmosis seawater desalination devices, the system can improve the peak shaving capacity of nuclear power plants and alleviate the water shortage in coastal cities. Through the analysis on peak shaving operation modes for the water/electricity cogeneration system of nuclear power plants, it is concluded that it is desirable for the reverse osmosis desalination devices to be operated at “12-1-10-1” (50% load by day and 100% load by night) variable load mode when the nuclear power units are under the full loading conditions. In this way, the peak shaving capacity of the water/electricity cogeneration system is 33% with the desalination cost of 3.62 Yuan/m³ and the peak shaving cost of 63 Yuan/MWh, indicating the promising future of the system application.

A Fast Estimation Method of Synchronous Generator Leading Phase Ability

CAO Kan, WANG Tao, XIN Jun-hui

2014, 47(1):  108-111.  DOI: 10.11930/j.issn.1004-9649.2014.1.108.3

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Generator leading phase operation is an economic and effective measure for voltage regulation and power quality improvement. In this paper, a simplified network model of generator access system and its equivalent circuit is built and the analytical expression of generator terminal voltage, auxiliary power voltage and generator power angle are derived. By solving these simultaneous equations, the generator leading phase ability under different typical active power can be calculated. The results of simulation for a 680 MW steam generator and a 250 MW hydraulic generator show that the proposed method can effectively improve the calculation speed and precision, and suitable for engineering practice.

Over-Voltage Invasion Wave Simulation and Lightning Protection Study of Large-Scale Photovoltaic Power Generation Stations

LI Hui, CHEN Jiang-bo, YIN Jing, ZHANG Jie, CHENG Ting, HE Yan, ZHANG Xi

2014, 47(1):  112-117.  DOI: 10.11930/j.issn.1004-9649.2014.1.112.5

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Lightning and over-voltage intrusion of the outdoor field of large-scale photovoltaic power generation stations is a major threat to photovoltaic power generation. In this paper, the ATP software is used for modeling simulation of the photovoltaic solar cell arrays, convergence boxes, inverters and surge protector devices(SPD) and other equipment. A study is made on the hazards of different lightning current amplitude, different grounding resistance and different lightning locations to the photovoltaic array and over-voltage invasion wave. Effective lightning protection results have been achieved through lowering the grounding resistance and adding the SPD to improve the over-voltage of the outdoor equipment of photovoltaic power generation stations.

Study on Grid-Connecting Control System of Vanadium Redox Flow Battery in Microgrids

LEI Jia-zhi, WANG Ke, LI Xun, LEI Jia-qiang

2014, 47(1):  118-122.  DOI: 10.11930/j.issn.1004-9649.2014.1.118.4

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Vanadium redox flow battery(VRB) is a large stationary electricity storage system with many potential applications in a deregulated and decentralized network. A VRB should be discharged under constant current or constant power by its grid-connecting control system. Otherwise, the battery life will be greatly reduced. Based on push-pull boost converter and single-phase inverter, a grid-connecting control system for a VRB in a microgrid is designed, in which the case of low voltage of storage battery is considered, and the constant discharging current of the battery and parallel operating of VRB and grid is achieved. In addition, a grid-connecting control system for a 2 kW VRB is simulated by using MATLAB platform and a model of a VRB, and a special experiment for control system is designed as well. Both the simulation and testing results have verified the robustness of the designed control system.

Study on Modeling and Control System Design Method for VSC-Based PCS Used in SMES

LI Zhi, FANG Xu-dong, ZHANG Yan-tao

2014, 47(1):  123-128.  DOI: 10.11930/j.issn.1004-9649.2014.1.123.5

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This paper chooses the voltage source converter based PCS as the object to study the method of its modeling and control. The structure of PCS, which includes the topologies of VSC and DC-DC chopper, was presented firstly, followed by the deduction of the low frequency state equation expressed by duty cycle. Then the state equation was linearized by non-linear transformation, the result of which was based to design the control system that achieves decoupled control between active power, reactive power and DC voltage. Finally, the ability of PCS to track power orders in the form of step change or sine change and the effectiveness of SMES system to stabilize output power of generator in single machine infinite bus system were checked using Matlab/Simulink software. The results of simulation show that PCS designed in this paper has the ability to trace power order in form of sine and step, accompanied by the strong resistance of DC voltage to disturbance, the SMES system interfaced by this PCS can accelerate the calm down of generator power oscillation, so enhance the stability of power system.

Analysis on the Application Mode of Radio over Fiber for Smart Grid

YAO Ji-ming, ZHENG Ze-huan, LIANG Yun, LI Bing-lin, ZHANG Hao

2014, 47(1):  129-132.  DOI: 10.11930/j.issn.1004-9649.2014.1.129.3

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Radio over Fiber (RoF) technology is the latest technology trends of modern communication technology, discussing the application mode in electric communication will have a certain reference value for the communication network construction for the smart grid. This paper discusses the application model of RoF technology in the smart grid, moreover, analyzes and elaborates the application advantages and difficult problems at present from transmission, substation and distribution of electricity in three aspects. Theoretical analysis shows that RoF technology has a precedent favorable conditions in the power system, adapting to the access network structure, and will play an important role in the development process of the electric communication.

Adaptive Impedance Matching of the PLC Based on PSO

XIAO Yuan-qiang, CAO Min, LI Chuan, LI Bo, CHEN Fu-yun, XIONG Xin

2014, 47(1):  133-137.  DOI: 10.11930/j.issn.1004-9649.2014.1.133.4

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Impedance matching circuit of power line carrier(PLC) is usually an unchanged passive circuit. An adaptive impedance matching system of PLC based on PSO is designed, and the objective function is built. The changes of load impedance are matched through adjusting the two capacitors in the π-type passive network. PLC with the capacitive, resistive and inductive load is researched through simulation, and the selected carrier frequency points are 150 kHz, 260 kHz and 480 kHz. The results show that the objective function obtains the optimal value gradually after 20 generations. Experiments prove that the particle swarm optimization algorithm based on the π-type passive matching network cans adaptive matching the changes of load impedance.

Research on Ultra-Low Emission Technology for CFB Boilers

SUN Xian-bin, SHI Zheng-hai, JIN Sen-wang

2014, 47(1):  142-145.  DOI: 10.11930/j.issn.1004-9649.2014.1.142.3

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Circulating fluidized bed(CFB) boilers are capable of clean combustion for various solid fuels. However, further studies are still needed on how to make CFB boilers meet the new national environmental standards of ultra-low emission of SO₂ and NO_x. By taking example of the engineering projects of CFB boiler, certain deep desulfurization and denitration technology schemes are put forward according to the contents of equivalent sulfur and volatile matter in coal. The analysis and discussions on key technologies are also conducted. The research results show that by adopting the proper schemes corresponding to various coal types, the SO₂ emissions can be maintained below 100 mg/m³ while the NO_x emissions can be stabilized below 100 mg/m³ for CFB boilers. For the high-volatile bituminous coal, in cooperation with the SNCR technology, the NO_x emissions can reach the ultra-low emission level of less than 50 mg/m³ for CFB boilers.

Performance of Solid Adsorbents Impregnated with Amines for Carbon Dioxide Capture

ZHAO Yi, LI Xu

2014, 47(1):  146-150.  DOI: 10.11930/j.issn.1004-9649.2014.1.146.4

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Capturing CO₂ from fossil fuel power plants is of great importance in the alleviation of carbon dioxide concentration ever-increasing in the atmosphere. As a kind of post-combustion CO₂ capture technology, solid adsorbentsare characterized as low energy consumption, low corrosion and favorable regeneration, which make it is promising to be widely used for CO₂ capture in the future. In this paper, the adsorption performance of solid amine adsorbents on CO₂ capture prepared by impregnation is introduced with the impacts of some factors emphasized, such as the substrate nature, the amine loading amount, the adsorption temperature and the moisture in the flue gas. The principle of the adsorbents is also analyzed and the adsorption capability of different adsorbents at the temperature of 75 ℃ is compared. The analysis concludes that compared to other solid CO₂ adsorbents, solid amine adsorbents are more suitable for carbon dioxide capture in the flue gas at high temperatures.

Analysis on Water Balance and Saving Schemes of Wet FGD System

CHEN Shi-yu, LI Xue-dong

2014, 47(1):  151-154.  DOI: 10.11930/j.issn.1004-9649.2014.1.151.3

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The influencing factors of water consumption, water saving methods and water balance are analyzed for the limestone/lime-gypsum wet FGD system. Moreover, the comparison between the water consumption of the FGD system before and after the low-temperature economizer modification in the phase II project of a power plant of Datang Group is conducted. It indicates that the water consumption in the FGD system is associated with the evaporated water in the absorber; the evaporated water can be decreased by reducing the gas temperature difference between the absorber inlet and outlet to realize in-depth water saving. According to the situation that water consumption in the wet FGD system of air-cooling units takes a large proportion of the overall water consumption of the plant in the west region, measures to keep the water balance are proposed.