Table of Content

05 June 2018, Volume 51 Issue 6

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Current Status and Challenges of Atmospheric Pollution Prevention and Control of Thermal Power Plants in China

LI Jianguo, ZHU Fahua, SUN Xueli

2018, 51(6):  2-10.  DOI: 10.11930/j.issn.1004-9649.201804084

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On the basis of the review and summary of the development history of atmospheric pollutant emission standards in thermal power plants of China, the promoting role and the resulting environmental effects of these standards or requirements in different stages, especially those for ultra-low emissions are analyzed on the development of atmospheric pollution control technologies in coal-fired power plants in China,. At present, the control of atmospheric pollutants in thermal power industry in China is at the stage of ultra-low emission, and the prevention and control technologies of atmospheric pollution in coal-fired power plants is at the leading edge of the world. For the three main conventional pollutants, such as dust, SO₂ and NO_x, the coal-fired power plants have achieved the state of cleanliness almost the same as the gas-fired power generation. Nevertheless, China's thermal power environmental protection is still facing many other challenges, such as CO₂ control, further reductions of regular air pollutants, wet desulphurization effect on ecological environment, disposal of hazardous waste scrap of SCR catalyst, non-conventional pollutants control, operation optimization of flue gas treatment facilities, etc. In this paper, the key areas and corresponding targets for research and development are also put forward.

The In-Depth Experimental Study on the Low Low-Temperature Electrostatic Precipitator Based on Pilot Platform

WU Jin, LIU Hanxiao, LI Jianguo, ZHAO Lin, XU Dongxu, LUO Jianyou, ZHAO Shengqing

2018, 51(6):  11-16.  DOI: 10.11930/j.issn.1004-9649.201802040

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Based on the 50 000 m³/h actual flue gas pilot test system, the total particle matters (TSP) are measured by using the conventional sampling gun plus glass fiber filter tube together with the integrated sampling head plus quartz filter membrane. In addition, PM_2.5 is measured by ELPI while SO₃ is measured by the independent R&D SO₃ sampling system, and specific resistance of fly ash is measured by using BDL type fly ash operating condition specific resistance tester. The test results show that the TSP concentration of ESP outlet are 11.6, 9.0 and 5.4 mg/m³ at the temperature of 130℃, 90℃, 80℃ respectively and the concentration of PM_2.5 are 0.8, 0.4 and 0.2 mg/m³, such that significant emission reduction of TSP and PM_2.5 is observed. The SO₃ concentration of ESP outlet are 1.25, 0.10 and 0.14 mg/m³, respectively, with the corresponding removal efficiency of the ESP system as 22.84%, 96.15% and 96.61% respectively, which means the low-low temperature ESP system is capable of removing the majority of SO₃ from flue gas. The ash condition resistivity of ESP inlet are 3.02×10¹³, 6.15×10¹² and 5.24×10¹¹ Ω·cm respectively.

Development and Application of PM_2.5 Trapping and Removal Device Based on Turbulence Coupled with Bipolar-charged Particle Coagulation

LI Ning, YUAN Weifeng, LIU Hanxiao, ZHAO Lin, XU Dongxu, LUO Jianyou, GUO Ying

2018, 51(6):  17-25.  DOI: 10.11930/j.issn.1004-9649.201711003

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Regarding the technical bottleneck as difficulty in PM_2.5 particle charging in conventional electrostatic precipitator (ESP), the particle coalescence technique based on turbulence coupled with bipolar-charged mechanism can promote the PM_2.5 coalescence economically and efficiently, which is of great help for ESP to remove PM_2.5 effectively. Apparently it has the highest engineering application value among a variety of particle coalescence technologies. In this paper, the structural optimization of gas duct PM_2.5 trapping and removal device are carried out, then the key components structure and the main parameters of bipolar charged area and turbulent aggregation area are determined. The total flue dust can be reduced by 20.3%, and PM_2.5 emissions can be reduced by 30.1%. In addition, the PM_2.5 trap synergistic device are developed and the best mixing scheme for bipolar charged particles are determined. The total dust can be reduced by 17.3%. After coupling with low-low temperature electrostatic precipitators with rotating electrodes, PM_2.5 can be reduced by 37%. The multi-clock arrangement and combination mode can flexibly adapt to the different requirements of the actual engineering conditions, and meet the urgent requirements of environmental protections for PM_2.5 management of coal-fired power plants.

Numerical Study on the Heat Transfer, Fouling and Erosion Characteristics of the Elliptical Tube Bundle with Different Extended Heating Surfaces

YE Xiafeng, DING Honglei, PAN Weiguo, PAN Yanxing

2018, 51(6):  26-32.  DOI: 10.11930/j.issn.1004-9649.201802099

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The erosion and fouling problems are common in low-temperature flue gas heat exchangers, which can cause the increase of the maintenance cost as well as the decrease of the heat transfer coefficient and the instability of equipment operation, etc. In this paper, the reliable computational model and methods are applied to investigate the effect of different extended surfaces of the elliptical tube bundle on the heat transfer, fouling and erosion characteristics. The results show that three kinds of fin elliptical tubes with different extended surfaces have different heat transfer, fouling and erosion characteristics. The H-finned tube bundle has the best heat transfer performance, slightly better than that of double H-finned tube bundle, while the rectangular finned tube bundle is slightly worse than the formers. The H-finned tube bundle has better anti-fouling performance due to the existence of slotted fin, however, the anti-erosion performance of double-H finned tube bundle is slightly better than that of H-finned tube bundle.

Study on the Method of Sampling of Coagulated Particulate Matter (SO₃) in Coal-Fired Power Plants

ZHANG Dejun, LIU Hanxiao, ZHAO Lin, YUAN Weifeng, FANG Xiaowei, XU Dongxu, LUO Jianyou

2018, 51(6):  33-36,149.  DOI: 10.11930/j.issn.1004-9649.201708286

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Regarding the existing drawbacks in the current sampling methods for condensable particulate matter (SO₃), the traditional sampling units should be optimized to improve the collection efficiency of SO₃. Several sampling schemes are compared respectively, including vertical and horizontal condenser plate, condensing coil and isopropyl alcohol absorption. The results show that for the capture effect of SO₃ in flue gas, the outcome of the special vertical and horizontal condenser is almost the same, while the two-stage condensate coil exhibits the best performance, followed by the isopropanol absorption method, and the one-stage condensate coil the poorest. Based on this, the best capture scheme coupled two-stage of vertical condenser coil (65℃ constant temperature water bath) with 80% isopropyl alcohol absorption (0℃ ice bath) is put forward, and the onsite testing is carried out. The test results show that SO₃ are captured by all of the above three units. However, the collection efficiency of the first stage condensate coil is the highest, then decreases in turn, and the SO₃ capture ratio of the second stage condensate coil and isopropyl alcohol absorption unit is about 26%~40%.

Analysis on Key Technologies of High Efficiency Desulfurization and Collaborative Dust Removal

DU Zhen, WEI Hongge, ZHANG Yang, ZHU Yue

2018, 51(6):  37-41.  DOI: 10.11930/j.issn.1004-9649.201802042

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In order to systematically study the technologies of high efficiency desulfurization and collaborative dust removal, the actual application status of high efficiency desulfurization and collaborative dust removal in typical unit has been analyzed. It is clarified that to implement high efficiency desulfurization and collaborative dust removal technology the low-low temperature electric dust removal technology and high efficiency desulphurization technology should also be taken into account. The low-low temperature electric dust removal technology requires not only strict control on smoke temperature and ratio of ash to sulfur but also well-designed flow field, flow rate and the proper material selection to prevent the flue gas cooler from wearing and leaking. High efficiency desulfurization technology requires optimized tower spray layer and demister layer flow field, reasonable tower facilities spacing and flow rate settings as well as adequate spray coverage and appropriate nozzle and defogger configuration. The ultra-low emission of SO₂ and dust can be realized effectively by virtue of the synergistic action of low temperature electric precipitating technology and high efficiency desulphurization technology. Therefore, the low-low temperature dust removal technology in combination with efficient desulfurization synergistic dust removal technology is a more preferred technical route for dust and SO₂ ultra-low emission.

Numerical Simulation of Key Parameters of Zero Discharge System for WFGD Wastewater

WENG Weiguo, SUN Jianguo, LI Qinwu, ZHOU Can, JIANG Shanxing

2018, 51(6):  42-47.  DOI: 10.11930/j.issn.1004-9649.201802041

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The evaporation technology of WFGD wastewater in the flue gas before it enters ESP is studied by numerical simulation. The impacts of the six parameters on droplet residence time and evaporation distance are investigated, i.e., droplet size, flue gas temperature, flue gas velocity, wastewater volume, jet velocity and jet angle of wastewater. The results show that the higher of the flue gas temperature, the smaller of the droplet size and the injection amount, the less residence time of the droplet will last. With the increase of flue gas velocity, injection velocity and injection angle, the residence time tends to decrease first and then rise afterwards. The research results can provide support for project decision-making process and design optimization.

Technical Study and Demonstration Project on the Quality Control and Drying of Terminal Wastewater in Coal-Fired Power Plants

YAO Zilin, YUAN Weizhong, CHEN Biao, LIU Chunhong, TONG Xiaozhong

2018, 51(6):  48-53.  DOI: 10.11930/j.issn.1004-9649.201802100

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In compliance with the requirement for zero wastewater discharge in coal-fired power plants, the quality control technology and drying technology of the terminal wastewater are studied and discussed in this paper in order to properly dispose the terminal wastewater based on the analysis of the wastewater quality and the existing wastewater zero discharge treatment technology. The drying process and its influencing factors of saline drip are researched. After the comparison of atomization and flue gas distribution, the technology of treating terminal wastewater by flue gas bypass drying is finally determined to be applied, and then corresponding engineering application is carried out, which is the first project demonstration project completed in China. Moreover, the engineering effect and operation economy are evaluated.

Probabilistic Load Flow Calculation of Power Systems Considering Wind Power Dispatching Strategies

YANG Xiaojing, QIN Chao

2018, 51(6):  54-59.  DOI: 10.11930/j.issn.1004-9649.201608029

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The paper proposes a method to calculate multi-point linearization probabilistic power flow of power systems considering the dispatching strategies of wind power. The proposed approach is based on the theory of Cumulant and Gram-charlier series, and takes into account the uncertainty of wind power, conventional power generation and load. To ensure accuracy, multi-point linearization technology is applied. In addition, the dispatching strategies of wind power are also considered in power flow calculation, as it did in power system economic power dispatching. Compared with simulation-based methods, the proposed approach can not only effectively improve the calculation accuracy compared with Cumulant and Gram-charlier series methods, but also can overcome the disadvantage of conventional probabilistic power flow calculation, i.e., the unbalanced power fluctuations are entirely absorbed by the slack bus. Therefore, the calculation results obtained through the proposed method is more consistent to reality.

Optimization Design Method of Short Circuit Voltage of Main Transformer in Substation

ZHAO Shuai, ZHANG Lai, LEI Guangyu, GAO Yi, ZHAO Gaoshuai, WU Jiaowen, FANG Fei, SONG Yang

2018, 51(6):  60-66.  DOI: 10.11930/j.issn.1004-9649.201706109

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Appropriate selection of the short circuit voltage of the main transformer is one of the key problems in the planning and design of the substation, which determines the security, reliability, and economy during the substation operation. Firstly, functional relationships are established theoretically based on the impedance model of transformer available for the short circuit analysis. The functional relationships contain parameters of short circuit voltage and short circuit current, parameters of short circuit voltage and reactive power compensation. On these bases, the optimization design method is presented considering two constraints, including short circuit current level and reactive compensation capacity. Case study on the design of typical 220 kV substation verifies the correctness and effectiveness of the proposed method for the optimization of the parameters of short circuit voltage.

Industry Status Analysis and Key Technology Expectation for Insulated Tubular Busbar

RUAN Ling, LIU Rui, ZHAO Jiankang, XU Zhibin, YANG Fan, ZHU Sirui, LI Wenpei

2018, 51(6):  67-76.  DOI: 10.11930/j.issn.1004-9649.201702023

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As a new type of current-conveying equipment at low voltage side, insulated tubular busbar has been increasing rapidly in recent years for its unique advantages. However, the frequent failures and adverse consequences in the application of this kind of equipment have seriously restricted its further extension. Based on extensive investigation of the manufacturers, applications and related documents of insulated tubular busbar, this paper summarizes the industry status and the technological characteristics of this equipment, analyzes the typical failure in the application, sums up the common problems in the production and application of this kind of equipment, and proposes the key technologies which should be researched in the future to solve the above problems. This article proposes that, the characteristics of the insulated tubular busbar exactly meets the needs of high-capacity, high safety level and flexibility for current-carrying which are demanded by the industry customers; the manufacture,the application of this kind of equipment and the related researches have just started in China; the common failures in the operation reveal that there are quite deficiencies in the aspects of design, manufacture, assembling, operation and test during whole processes of the insulated tubular busbar; and methods in the aspects of engineering level and management system should be developed to optimize the equipment and improve its operating reliability.

Application Analysis and Evaluation Index Research of Dual Channel Line Protection

YANG Guosheng, GUI Qiang, ZHANG Lie, XU Kai, RUAN Siye

2018, 51(6):  77-82.  DOI: 10.11930/j.issn.1004-9649.201704067

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The channel operation condition directly affects the action of line protection, thereby affecting the safe and stable operation of power grids. Starting with the principle of dual channel line protection, analyzing the advantages of dual channel line protection device, the devices made by several main manufacturers of home and abroad is compared in detail. This study also introduces the application of dual channel line protection in the two major power grids in China, and proposes several evaluation indexes of the dual channel line protection. It is suggested to increase the use of dual channel line protection in 500 kV and above voltage system, and make a scientific and reasonable evaluation of their configuration and operation. The purpose is to find out the weakness in the operation process and ensure the safety and stability of the power grids.

Determine Method of the Transformer Winding Looseness Defeat Based on Vibration

ZHOU Yu, MA Hongzhong, HUANG Fengwen, GU Jinping, CHEN Taotao, GONG Jiewei, ZHU Shizhen

2018, 51(6):  83-88.  DOI: 10.11930/j.issn.1004-9649.201711096

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Accurate defeat diagnosis on transformer winding looseness is investigated experimentally and theoretically in this paper. An eigenvalue of transformer winding looseness defeat is defined based on the pre-compression force. The eigenvalue vary monotonously with the pre-compression force, which is used in defeat diagnosis. This method is suitable for on-line monitoring under load fluctuations for the reason that the eigenvalue is unaffected by the current. In the experiments winding looseness faults are set by different pre-compression forces which are measured by the bridge circuit consisted of strain gauges and resistors. Hammering method is used to measure the natural frequency. The impact of pre-compression force's changes on the natural frequency is explored. Effective measurement points are not influenced by the resonance. Defeat threshold values and warning threshold values are selected after analyzing the characteristics of the effective measurement points under the circumstance of different pre-compression force and current to achieve winding looseness defeat diagnosis and defeat phase localization.

Analysis of the Influence of Seasonal Frozen Soil on the Grounding Safety Parameters of Substation

LUO Chen, MA Li, ZHAN Min, YANG Feng, ZHANG Dapeng, CAO Xiaobin

2018, 51(6):  89-95.  DOI: 10.11930/j.issn.1004-9649.201609044

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After soil freezing in winter, the soil resistivity increases sharply, and the soil resistivity and depth of frozen soil layer vary with soil temperature, which not only affects the values of the contact voltage and step voltage, but also the allowable values of the step voltage and contact voltage. In order to explore the effect of seasonal frozen soil on the grounding safety of substation, the seasonal frozen soil model is established in this paper. The influence characteristics of seasonal frozen soil on the resistance, contact voltage and step voltage of substation grounding system are archived by simulations; the maximum allowable safety values with different grounding resistances, contact voltages, and step voltage are analysed. Finally, the methods to improve the grounding safety performance in the frozen soil region are studied. When the depth of frozen soil is less than the buried depth of grounding grid, the step voltage and touch voltage are effeted by the soil resistivity of the lower layer, and the grounding system is relatively safe. If the frozen soil depth is larger than the one of the grounding grid, there are sharp rises in the touch voltage and step voltage, which exceeded the safety value. At this time, the vertical grounding electrodes can effectively reduce the grounding resistance and limit the contact voltage and step voltage.

Analysis of the Lightning Overvoltage of Substation in Melting Ice Insulated Ground Wire System

MA Yutang, MA Yi, CAO Xiaobin, HUANG Ran, CHEN Kui, ZHOU Fangrong

2018, 51(6):  96-101.  DOI: 10.11930/j.issn.1004-9649.201608030

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The ground wire using full insulation design is employed in the direct current (DC) melting ice technology. But the design of insulated ground wire will affect the largest over-voltage level of electrical equipment in substation. In this paper taking the actual 500 insulated ground wire as an example, the way of erected melting ice insulated ground wire was described. The insulated ground wire simulation model of 500 kV substation was established using ATP-EMTP simulation software. The influence of erection of the melting ice ground wire of 500 kV substation lightning overvoltage was analyzed. The influences law of the lightning-point distance, tower grounding resistance and arrester configuration on the lightning overvoltage of substation equipment were summarized. The results show that the melting ice insulated ground wire has little effects on the largest overvoltage of substation equipment. The closer of the lightning point to the substation is, the greater of over-voltage of substation equipment is. The bus arresters have well protective effects on the substation equipment. The largest overvoltage of substation equipment can be declined by using the bus arresters. The overvoltage level of substation equipment can decrease with the decrease of tower grounding resistance. The results can provide a certain reference to run and design the insulated ground wire in practice.

Application of PSO-based Wavelet Algorithm in MOA Aging Diagnosis

LIANG Kedao

2018, 51(6):  102-106.  DOI: 10.11930/j.issn.1004-9649.201705062

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To solve the de-noise problem of metal oxide arrester (MOA) leakage current, a PSO (particle swarm optimization)-based wavelet de-noising algorithm is proposed. Firstly, the db₅ wavelet is used to decompose the leakage current. Secondly, the threshold value is set and the processed wavelet coefficients are reconstructed. Finally, de-noising is achieved through PSO threshold value and the results are verified through MOA current modelling. Studies show that by decomposing the leakage current with db₅ and optimizing the threshold value with PSO, the values of c₅, c₄, c₃, c₂ and c₁ are found to be 0.32, 0.20, 0.13, 0.02 and 0.01, respectively. The SNR (signal to noise ratio) after de-noise is raised by 7dB compared with the result when just using the stationary wavelet. The results indicate that the de-noising effect of PSO-based wavelet de-noising algorithm is better than that of wavelet de-noising algorithm.

Optimal Multiplier Method and its Application in Power Flow Calculation for AC/DC Power Grids

FANG Chaoxiong

2018, 51(6):  107-112.  DOI: 10.11930/j.issn.1004-9649.201801020

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The optimal multiplier method has been widely applied to practical power system problems, due to its high convergence reliability, the superior performance in dealing with ill-conditioned power flow, and the ability to find the least square solution for infeasible power flow equations. In this paper, the steady-state equivalent model of voltage source converters (VSCs) in the rectangular coordinate system is established, transforming the power flow calculation problem of AC/DC power grids into cracking a set of quadratic equations, which decouples the model and solution methodology of power flow calculation, and reduces the complexity of the corresponding computer programs. To deal with non-convergence issue in large-scale AC/DC power flow calculation, a unified iteration model is proposed to improve the convergence performance considering multi-slack generators and multi-generator coordinated voltage regulation. Simulation results of Fujian power grid with the Xiamen VSC-HVDC project validate the effectiveness of the proposed models and methods.

Design of Remote Emergency Channel Platform for Electric Information Acquisition System

ZHANG Hailong, CHEN Lei, TANG Yue, TAN Manhong

2018, 51(6):  113-120.  DOI: 10.11930/j.issn.1004-9649.201708138

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At present, in addition to the wired mode (optical fiber, PLC), a variety of new wireless communication technologies (LTE, WiMax, etc.) are also widely applied to the power user electric energy data acquire system. These kinds of wireless communication system use base stations to gather and manage large terminal information within the region. However, when failures of the base stations happen, it couldn't be obtained wide range of power users information which affects the normal operation of the whole power transmission and distribution system. In this paper, an emergency plan by building a low altitude wireless communication platform using unmanned aerial vehicles is designed, and then analyzed and modeled the wireless channel in this scenario. On the basis of this, a long distance uplink channel transmission scheme based on broadband OFDM is designed, and then the communication performance and system capacity of the scheme is analyzed. Simulation results show that the proposed scheme can meet the emergency repair stations within 10 km.

Research on Integration Model Construction and Integration Technology for Future State of Power Grid

YANG Qijing, ZHANG Yong, ZHAI Mingyu, NING Jian, JI Xuechun, LI Hao

2018, 51(6):  121-128.  DOI: 10.11930/j.issn.1004-9649.201702101

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With the increasing scale and complexity of smart grid in China, the demand for future state grid model is increasingly high. At this stage, the scheduling automation system lacks fast and efficient modeling methods for future grid state modeling, and lacks the coordination and fusion mechanism of future models between the upper and lower level scheduling systems. By studying the architecture of the future model management system of the power grid, the future version maintenance ring of the model is realized through the message middleware-based interaction technology and the fusion method of the future model considering the granularity of the plant station, without affecting the security and stability of the real-time system. The model also uses data fragmentation and distributed file database technology, the rapid construction of the environment realizes the efficient management of the integration of the future model of the integrated network, and meets the needs of different applications for the future model multi version maintenance and provides a complete set of solutions for the application calculation.

Application and Key Technologies of Submarine Cable Integrated Monitoring

WU Wengeng, LIN Xueqian

2018, 51(6):  129-135.  DOI: 10.11930/j.issn.1004-9649.201708189

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Submarine cable is an important passage of cross-sea power delivery. Due to the lack of effective monitoring technology, the power failure and fault of submarine cable usually occur. In this paper, the submarine cable compound optical fiber is used as the sensing element to build a submarine cable integrated monitoring system. The system can moditor the operation state of submarine cabel in real-time. The technical principles of Brillouin scattering on the strain and temperature and the principles of Rayleigh scattering on vibration sensitivity are introduced. The operation temperature, strain state and vibration of submarine cable can be monitored. The results can support the stable operation of the cross-sea power grid. The research results have been getting markable effect in practice and have wide prospect in application.

Wind Power Reliability Evaluation Method Based on Wind Power Unit Grouping

LI Jianfeng, HAN Qin, LIU Zhanli

2018, 51(6):  136-143.  DOI: 10.11930/j.issn.1004-9649.201711021

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In order to evaluate the reliability of wind turbines more effectively, on the basis of analyzing and comparing the wind turbine reliability evaluation procedures at home and abroad, a new method is proposed to evaluate the reliability of the wind farm resource, the wind turbines group, the wind farm and the single wind turbine, The calculation of the reliability indexes of resource and wind turbines group is added to the new method. Compared with the existing evaluation procedures and methods, the new method fits better with the current situation of wind turbine development in China and the characteristics of reliability management of wind turbine units. At the same time, it has the advantages of a small amount of data processing and less burden of wind farm operation and management.

Effect of Wind Turbine Tail Flow Disturbance on the Atmospheric Bottom Boundary Layer

WU Zhengren, LI Fei, LU Tingting, LIU Mei

2018, 51(6):  144-149.  DOI: 10.11930/j.issn.1004-9649.201708056

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The turbulent characteristics of wind turbine tail flow and its influence on the lower boundary layer of the atmosphere are of great importance. In this paper, the tail flow of single 5MW wind turbine under the same velocity profile but different temperature layers is numerically simulated by using Reynolds Average N-S equation (RANS). By analyzing the variation and characteristics of the meteorological factors of wind turbine downstream velocity, temperature and turbulence intensity in different settings, the influence mechanism of wind turbine operation on the lower boundary layer of atmosphere is obtained, which provides certain theoretical basis for the establishment of high efficiency wind farm. The results show that the wind flow velocity decreases significantly after passing through the wind turbine with the maximum attenuation occurrence near the hub. The temperature varies greatly under different stable layers. Meanwhile, the vortex produced by the blade rotation of the wind turbine interacts with each other, which will intensify the turbulence disturbance.

Analysis the Impact of Photovoltaic Power Station's Integration into Rural Distribution Network

WANG Jifei, WANG Yongxing, YANG Yujing, WANG Yanping

2018, 51(6):  150-154.  DOI: 10.11930/j.issn.1004-9649.201708111

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The capacity of photovoltaic power station connected to the grid is increasing, and its impact the rural distribution network can't be ignored. In order to evaluate its influence, firstly, the IEEE14 node model is improved considering the characteristics of a rural distribution network in Zhangjiakou area. Secondly the improved power system model and the photovoltaic power station model are established in the power system analysis toolbox (PSAT). The impacts of grid-connected photovoltaic power on the voltage stability and line loss of rural distribution network are investigated. In addition, time domain simulations with two kinds of typical load changes are carried out. The simulations show that the photovoltaic power station has a positive role on promoting static and transient voltage stability and reducing line loss of local rural distribution network.

Prospects for the Application of Hydrogen Donors in Carbon Capture and Resource Utilization

ZHAO Yi, WANG Tianhao, WANG Han, WANG Xiaohui, HAO Siqi, WANG Yongbin

2018, 51(6):  155-159.  DOI: 10.11930/j.issn.1004-9649.201703022

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Large amount of carbon dioxide (CO₂) emissions have significantly exacerbated the greenhouse effect and the deterioration of the ecological environment. The catalytic transfer hydrogenation method has been extensively studied and technically mature in the field of CO₂ resource utilization. In this paper, the study of the CO₂ catalytic hydrogenation technology with gaseous hydrogen as the main reductant, the reduction characteristics of the hydrogen donors, and current applications are summarized. The pros and cons of the studies are presented as well. Finally, suggestions are given for future research on the application of the hydrogen donors in the field of carbon capture and resource utilization, aiming to provide references for the future development of CO₂ resource utilization.

Potential Analysis of Synergetic Mercury Removal from Coal-Fired Flue Gas on Purification Equipment after Retrofitting of Ultra-low Emission

CHEN Kunyang, GUO Tingting, WANG Haigang, HU Dong

2018, 51(6):  160-165.  DOI: 10.11930/j.issn.1004-9649.201707018

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The ultra-low emissions retrofitting improves the flue gas purification equipment in the coal-fired power plant greatly in terms of the equipment capacity and quality. In order to provide the basis for decision-making on the control of mercury emission, the synergistic mercury removal efficiency of the purification equipment is analyzed. The results show that the SCR system retrofitting can increase the oxidation efficiency of Hg⁰ and promote the mercury removal efficiency of the dust removal equipment and the desulfurization equipment. The mercury removal effect of the low-temperature electrostatic precipitator and the electrical fabric filter can reach up to 40%. The desulfurization equipment with a high efficient demister can remove mercury in a synergistic manner with an efficiency of 96%. However, due to the low Hg²⁺ concentration at the outlet of the dust collector as well as the low dust concentration and the small particle size, the influence on mercury removal efficiency in flue gas is limited from the single tower retrofitting and the wet electrostatic precipitator in the desulphurization system. It is also possible that the mercury emission concentration at the outlet of the desulphurization system is slightly higher than that at the inlet after the single tower retrofitting.

Pretreatment Device Design and Pilot Application of Desulfurization Wastewater in Coal-Fired Power Plants

LIAN Kunzhou, HU Teli, WANG Yongqian, JIAO Xuchang, WANG Jing, CAO Hongmei, MAO Jin, FAN Kaiyuan

2018, 51(6):  166-171.  DOI: 10.11930/j.issn.1004-9649.201708200

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According to the characteristics of desulfurization wastewater in the coal-fired power plant, the desulfurization wastewater pretreatment method of the integrated softening and clarifying-ultrafiltration is proposed in this paper. The pilot project testing is completed in a coal-fired power plant in Shandong province. The study includes the removal efficiency of integrated softening and clarifying on Ca²⁺, Mg²⁺ and the turbidity, the operating pressure of the ultrafiltration system, the flow and turbidity of the product water, and the chemical cost of the pretreatment process. The results show that the content of Ca²⁺ decreases from 400~660 mg/L to 25 mg/L and the content of Mg²⁺ decreases from 5 310~15 689 mg/L to 10 mg/L after the treatment of desulphurization wastewater by integrated softening and clarifying-ultrafiltration, respectively, with the turbidity being no more than 2.0 NTU. The ultrafiltration system operates stably and the turbidity of product water is no more than 0.1 NTU, SDI value is less than 3.0, which can meet the required water quality conditions of the reverse osmosis system. The study results of the integrated softening and clarifying-ultrafiltration can provided important data for the research on the zero wastewater discharge technology in the power plant.

Trading Model of Green Electricity Certificate Considering Preferential Prices

WANG Qiang, TAN Zhongfu, TAN Qingkun, YU Xiaobao, PU Lei

2018, 51(6):  172-177.  DOI: 10.11930/j.issn.1004-9649.201708282

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On the basis of analysis of the price forming mechanism of tradable green electricity certificate, the impacts of the subsidy amount of renewable energy price, the subsidy settlement and delay cycle, and the consumer preference on the sales price of green electricity certificate are studied. Furthermore, to study the transaction price of green electricity certificate under random condition, a model of green electricity certificate transaction based on Monte Carlo method is established. By applying the model in a large coal power enterprise in Inner Mongolia where the green electricity certificate price of wind power and photovoltaic is subscribed, the case study proved the practical values of the model.

Driving Factor Analysis for the Power Consumption and Load Forecasting of Beijing City

WANG Bin, ZHANG Xinxin, JI Ling, XIE Yulei

2018, 51(6):  178-184.  DOI: 10.11930/j.issn.1004-9649.201803151

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Reliable and effective medium- and long-term load forecasting is an important basis for power generation and transportation. To achieve this goal, an exponential decomposition analysis based load forecasting method is proposed in this paper, identifying and sorting the key effect factors. Combining the variation trends of the identified key effect factors as well as the social economy, multiple simulation scenarios can be generated for medium- and long-term load forecasting. The historical load and socio-economic data of Beijing city from 1985 to 2014 are selected as the input, and the key effect factors for the load growth are demonstrated. Finally, this paper ends with the load forecasting of Beijing city for the 13th Five-Year Period.