Table of Content

18 November 2015, Volume 48 Issue 11

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Genration Technology

Online Sliding Pressure Optimization of 1 000-MW Ultra Supercritical Unit Based on Valve Point Control

ZHU Yaqing, ZHANG Xi

2015, 48(11):  1-6.  DOI: 10.11930/j.issn.10.11930.2015.11.1

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Aiming at the existing problem in the optimization of sliding pressure, the effects of back-pressure vacuum and extraction volume on optimal sliding curve are analyzed for the condensing turbine. The online energy-saving control strategy targeting at valve point optimization is proposed, which can improve the response of main steam pressure and unit load in combination with CCS optimization. Thus the CCS control quality is enhanced and the main steam pressure can change along the optimal sliding curve quickly and smoothly. In this way the CCS control problem caused by sliding pressure optimization is resolved. Through the applications on two 1 000-MW ultra supercritical units, it is shown that the units are able to operate always along the optimal sliding pressure curve no matter how the ambient temperature or the extraction volume changes. Therefore, the objective of economic operation is achieved.

The Application and Analysis of Fast Cooling System in Siemens 1 000-MW-Turbines

SU Guoqiang, WANG Donghui, SHI Jun

2015, 48(11):  7-12.  DOI: 10.11930/j.issn.10.11930.2015.11.7

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Generally, some certain time of turning gear is needed after a steam turbine shutdown. However, long-time turning gear will definitely extend the overhaul period and increase the operating costs of the related oil system. For the purpose of shortening the repairing period and conserving energy, fast cooling is adopted to accelerate the cooling rate of the internal components and reduce the turning gear period after the turbo set outages. Under natural cooling conditions, it takes about 12 to 15 days from turbine tripping to turning gear being switched off; but when fast cooling is adopted, it takes less than 5 days, saving 7 days at least. Regarding the typical fast cooling cases of Siemens 1 000-MW steam turbine, this paper presents the fast cooling operating procedures and analyzes some existing problems, and finally summarizes the procedure and controls for reference.

Retrofit of Anxial-Flow IDF with Variable Frequency Technology in 680-MW Ultra-Supercritical Units

GUO Yongming，LIU Guanqi，ZHANG Hao，ZHAO Yali

2015, 48(11):  13-15.  DOI: 10.11930/j.issn.10.11930.2015.11.13

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Taking account of the severe energy waste from the induced draft fan (IDF) in the large ultra-supercritical power generating unit, the retrofit scheme with frequency conversion technology is adopted. It is evaluated as the better solution to upgrade the automation level of IDF and improve the starting performance of electric motors. Moreover, the working principle of the frequency converter is presented. The practice results show that after the retrofit, the house service rate is significantly improved. Thus, the purposes of energy conservation and emissions reduction as well as anti-mechanical wearing are realized.

Influence of Major Operating Parameters of HP Mill on Coal Fineness and Specific Power Consumption

YUE Junfeng, DING Jianliang, CHEN Bo, ZOU Lei, ZHANG Enxian, HUANG Yaji

2015, 48(11):  16-21.  DOI: 10.11930/j.issn.10.11930.2015.11.16

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In this paper, the separation strength parameter“a” is proposed based on the dynamic classifier principle. A static model describing the influence of mill capacity (B), primary air rate (Q) and rotational speed of dynamic classifier (n) on coal fineness (R90) and specific power consumption (Em) is also established. Based on the model, the influence and sensitivity of the operation parameters on coal fineness and specific power consumption are analyzed, from which following conclusions are drawn: α/B is exponential to coal fineness (R90) and strongly linear to specific power consumption (Em); Em demonstrates linearity to ln (R90). The influences of mill capacity (B), primary air flow and rotational speed of dynamic classifier on R90 are independent of each other but not independent on Em; when n and Q change, the changes of R90 and Em are two times of those when B changes. The impact of operation parameters on R90 is three times of that on Em.

Intelligent Monitoring of Resins Separation and Transportation for Mixed Bed Polisher

TIAN Wenhua, LEI Junru, ZHU Xiaoliang, QIAN Yin, YE Zhou, LIU Yiran

2015, 48(11):  22-25.  DOI: 10.11930/j.issn.10.11930.2015.11.22

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The poor and unstable effects of resins separation and transportation for the mixed bed(MB) polisher due to the lack of effective monitoring have greatly affected the operation of the MB polisher. An intelligent monitoring instrument of resins separation and transportation (IRIC) is therefore developed to solve this problem. This instrument is able to not only accurately inspect the terminal point of resins separation and transportation, improving separation effect of exhausted resins, but also adjust a ratio of cation to anion resins depending on the requirement to increase the periodic water production of the MB polisher. In 2014, IRIC was applied to the condensate polishing system in the 2×350-MW supercritical coal-fired units in Hainan. The operational reliability of the MB polisher has been highly improved, with the periodic water production being increased from 26 000 m3 to 82 000 m3 times of resins regeneration have been significantly decreased, saving 112 tons of acid and base, 31 000 m3 of demineralized water and 62 000 m3 of fresh water; annual supplemental resins have been decreased by 3%, producing an annual direct benefit of about 1.1 million RMB.

Recovery Method of Oil Contaminated Resin in Condensate Polishing System

PENG Zhanghua, CUI Huanfang, WANG Guangzhu, LUO Chunren, CHEN Ping, ZHANG Qingyu

2015, 48(11):  26-29.  DOI: 10.11930/j.issn.10.11930.2015.11.26

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Generally, resin particle aggregation, resin floating and the reduction of cycling water production often occur when the ion exchange resin is contaminated by the oil in the condensate polishing system, which endangers the safe operation of the units. In this paper, aiming at these problems, through the analysis of the performance and status of the contaminated resin, the economic and feasible recovery method is developed. The practice shows that no aggregation or floating is observed in the oil contaminated resin after the treatment with the new recovery method. The resin separation is effective and the water quality is recovered to the pre-contaminated level, meeting GB/T 12145-2008 requirements.

Study on Optimization Design and Test of Steam Ejector for Seawater Desalination Systems

LI Anran

2015, 48(11):  30-33.  DOI: 10.11930/j.issn.10.11930.2015.11.30

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The performance of steam ejector does have effects on the heat utilization rate of the seawater desalination system in power plants. The traditional ejector design adopts Sokolov design method, which uses too much experience coefficients and is inaccurate in mixed steam pressure calculation. Therefore, the designed performance of the ejector is low. In consideration of the shortages of this method, the design of the ejector mixing section is divided into two parts and the calculations of the mixing section area ratio and the throat shock are induced to revise the ejection coefficient calculation formula and variation operation curve equation. In order to verify the reliability of this modified method, an ejector model with the scale of 1∶20 is built and tested. In the test, the ejection coefficient, the variable injection pressure and the variable backpressure operation curve are measured and analyzed. The test results show that the operation performance of the ejector model designed with the new method is greatly improved and is consistent with the calculated results

Uncertainty Evaluation of Ion Chromatography in Trace Sodium Ion Measurement of Power Plant Water & Steam System

PAN Jun

2015, 48(11):  34-38.  DOI: 10.11930/j.issn.10.11930.2015.11.34

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In order to ensure the accuracy and reliability of the test data, it is necessary to evaluate the uncertainty of ion chromatography. Using the uncertainty evaluation methods, this paper analyzes and quantifies the main uncertainty sources of trace sodium in the power plant water and steam system measured by ion chromatography. The outcome of the uncertainty evaluation indicates that the uncertainty in the trace sodium measurement mainly results from the standard curve fitting. Other affecting factors include the repeatability, recovery and preparation of the standard solution.

Study on Granular Flow in Hoppers Using DEM Simulation

XIA Boshi, CAO Qiangli, ZHANG Shengping

2015, 48(11):  39-44.  DOI: 10.11930/j.issn.10.11930.2015.11.39

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Granules are mediums between liquids and solids. Different granules exhibit different characteristics with complex kinetic mechanisms. Fortunately, the microscopic dynamics of granule flow can be simulated using discrete element method(DEM). In this paper, the theory and development of DEM technique are presented. Moreover, the accuracy of computer simulation depends on how accurate the mechanical model is established. The typical mechanics models used in DEM technique as well as the kinetic studies of granular flow in hopper using DEM technique are illustrated, including the flow behaviour, the distribution of velocities and contact forces and the influences of particle properties. The study results are of the great importance for the practical applications of hopper storing practices, such as coal bins, ash bins and limestone hoppers.

Power System

Compensation Reactor Parameters Study of Symmetrical Voltage Applying Mode for On-site Partial Discharge Test of Ultra High Voltage Converter Transformer

XIE Qijia, PU Ziheng, DU Zhiye, WANG Tao, ZHANG Yadong

2015, 48(11):  45-48.  DOI: 10.11930/j.issn.10.11930.2015.11.45

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On-site partial discharge test of Ultra High Voltage(UHV) converter transformer requires good anti-jamming measurement and response capability due to high test voltage, specific requirement and complex field environment. Under symmetrical voltage applying mode, there is large potential difference at transformer winding terminal. It is also inconvenient to adjust reactor compensation and measure voltage and current. The equivalent method of capacitance network of Ultra High Voltage converter transformer is studied. Based on on-site test results, the simulation is performed and compensation reactor parameters are obtained.This work is supported by National Basic Research Program of China (973 Program) (No. 2011CB209404).

Investigation on Fault Arc Energy under Different Load Based on the New Time Varying Resistance Fault Arc Model

ZHENG Mengdi, WU Xixiu, YAN Ge

2015, 48(11):  49-53.  DOI: 10.11930/j.issn.10.11930.2015.11.49

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Electrical fire accidents frequently occurred in low voltage distribution systems of buildings are mainly caused by fault arc. The occurrence frequency and severity of electrical fires depend on energy generated by fault arc. Based on dynamic variation characteristics of circuit, a new time-varying resistance model of fault arc is proposed. Furthermore, fault arc voltage and current under different loads are obtained by using proposed model. Changes of fault arc energy under different load are discussed; and the relationship between fault arc energy and power factor is investigated. The results show that fault arc energy increases with increasing of active power and decreasing of power factor, which associated with high possibility of electric fires.

Research on the Difference Mechanism and Evaluation Indices of ACDC Control Measures for Improving Frequency Safety

LI Wei, CHEN Tao, FENG Li, LV Yazhou, LIU Fusuo, REN Xiancheng, BAI Shibin,DING Maosheng, XIANG Li

2015, 48(11):  54-59.  DOI: 10.11930/j.issn.10.11930.2015.11.54

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The traditional control sensitivity index could be a good measure to optimize the next direction of searching control strategy and avoid the negative effect. But the perturbation calculation is needed to obtain the sensitivity of each control measure, which would not be suitable for rapid online decision-making requirements. In this paper, from the standpoint of positive and negative effect of control measures, the mechanism of improving frequency safety sensitivity of various control measures is expounded. The conception and calculation method of the actual effect of frequency safety control is proposed. The fast evaluation indices of generator tripping and load shedding and HVDC modulation is also proposed, which could obtain the performance parameters of all control measures from one simulation. Actual power system simulation indicates that these evaluation indices have similar control sensitivity of the perturbation calculation and can significantly reduce the calculation quantity of simulation and improve the strategy searching efficiency for seeking out the practical optimal control strategy.

Modeling and Analysis of Electromagnetic Field around High-speed Railway Catenary

SUN Huijuan, LIU Jun, HUANG Xinde, JIANG Lei

2015, 48(11):  60-66.  DOI: 10.11930/j.issn.10.11930.2015.11.60

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A simulation model is established in this paper for the conditions of buildings, trains and people, and the finite element method is used to calculate and

Thermal Decomposition Energy of Nanoparticle Modified Transformer Oil

LI Jianjie, SUN Hongbo, LIU Jia, LV Yuzhen, WANG Wei

2015, 48(11):  67-70.  DOI: 10.11930/j.issn.10.11930.2015.11.67

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Nano-modification technique has shown a great potential in improving breakdown strength and aging property of transformer oil/paper insulation system. The thermal degradation process and property of nanoparticle modified transformer oil(nanofluid) play an important role in its practical applications. Based on thermal degradation kinetics theory, thermal degradation process of TiO2 nanofluid is investigated by using thermogravimetric method (TG) under five heating rates (5, 10, 15, 20 and 25 ℃/min). The main kinetic parameters of nanofluid is obtained respectively by using differential and integral method. The results indicate that mean activation energy of nanofluid is up to 61.38 kJ/mol and the obtained value is affected by the calculation methods. FWO method is more reliable than other methods with a correlation coefficient up to 0.997 80. The activation energy of the TiO2 nanofluid calculated by FWO method is 63.37 kJ/mol. All these results illustrate that nanomaterial-modification can increase the activation energy of transformer oil and improve its thermal decomposition behavior. This method provides a basis for thermal stability evaluation and overall performance of nanofluid.

Comparative Research of Sound Power Measurement Method on Transformer Scale Model

HU Junjie, FENG Tao, WANG Jing, ZANG Fuyao

2015, 48(11):  71-75.  DOI: 10.11930/j.issn.10.11930.2015.11.71

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In a semi-anechoic chamber, by using PULSE sound and vibration acquisition system, noise output signals of different measurement points on a scale transformer model under different operation conditions are measured and analyzed. By comparing two standards of acoustic radiation power calculation between GB/T 1094.10—2003“Power transformers Part 10: Determination of sound levels” and GB6882—86“ten point sound power approach”, the effects of different boundary conditions on acoustic sound power measurements are studied. Experimental results show that firewall has some influence on acoustic radiation power transformer. Under different acoustic boundary conditions, results from two test standard are very close and within 1 dB mismatch. The methods described in standards GB / T 1094.10—2003 is very accurate and stable according to the study.

Design of Sand-Prevention Measures for ±800 kV UHV Converter Station

CHANG Wei, TONG Fan, ZHANG Yuming, MU Huaning, SHEN Weihua, LI Xuepeng, CHEN Le, WEN Qian

2015, 48(11):  76-81.  DOI: 10.11930/j.issn.10.11930.2015.11.76

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For the converter station located in a sandy area, the dust will cause harmful impact on electrical equipment, buildings and structures in the station, and even threaten the safe operation of the station. Along with a large number of UHV DC projects planned in the sandstorm-prone areas in northwest China, it is thus imperative to carry out an in-depth study on the sand-prevention measures for the converter stations to ensure their successful construction and operation. Based on an investigation on the design and operation situation of the existing converter stations in sandy area, a summary and analysis is made on the specific sand-prevention measures for the electrical equipment, buildings and structures of the convertor station, which cab provide a technical support and reference to the design of the sand-prevention measures for the future power transformation projects, especially the UHV DC converter stations in the sandy area.

Modeling and Analysis for Calculation of Typical UHV Tower Foundation Grounding Resistance in Layered Soils

LIU Tongchui, PAN Wenxia, WANG Bing, DAI Min, HUANG Tao

2015, 48(11):  82-87.  DOI: 10.11930/j.issn.10.11930.2015.11.82

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Due to its large dimension and numerous vertical rods, the UHV tower foundation may penetrate a second soil layer of the horizontal layered soils. As a result, the conventional simplified method for computation of UHV tower foundation grounding resistance may cause large deviation, which can bring out uneconomic design. In order to solve this problem, the integral equation for electrostatic field is discretized in this paper carries by using MOM, which is programmed by C++ to obtain the numerical results. The grounding resistance is calculated with this algorithm for a typical UHV tower foundation, which proves the algorithm’s validation. An analysis is carried out on the relationship between the grounding resistance of UHV tower foundation and the modeling parameters of double-layer soil, which indicates that the thickness of the upper layer is the decisive factor for the grounding resistance of a typical UHV tower foundation, and when the upper soil is small in thickness, lowering the specific resistance of the lower layer is obviously effective for reducing the grounding resistance of tower foundation. It is therefore very important to accurately estimate the subsoil resistivity for the grounding calculation.

Evaluation Method of Primary Frequency Regulation Performance Applicable to Ultra High Voltage Transmission Line Tripping

LIANG Zhengyu, TANG Yaohua, GUO Weimin, CUI Meng, HAO Tao, DUAN Songtao

2015, 48(11):  88-93.  DOI: 10.11930/j.issn.10.11930.2015.11.88

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An evaluation method of primary frequency regulation (PFR) performance after ultra-high voltage (UHV) transmission line tripping is proposed in order to avoid accuracy problem with current evaluation method. Based on statistical results of normal PFR process, characteristics of PFR process after UHV transmission line tripping are obtained. A new PFT performance index system is established according to described characteristics to complement the problems with existing method. The proposed method can describe PFR process from different units after UHV transmission line tripping clearly and accurately. The application results in coordinated special inspection among key power units near UHV transmission line in Henan power grid provide reference data and guiding advice for PFR comprehensive treatment and accident recovery of UHV transmission line tripping.

EKPF-Based Dynamic State Estimation of Electromechanical Transient Process

YANG Zhenrui, GUI Jianzhong, SHAO Shuai, ZHAO Xiang, ZHENG Cunlong

2015, 48(11):  94-98.  DOI: 10.11930/j.issn.10.11930.2015.11.94

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A dynamic state estimation model(DSE) is built according to the dynamic characteristics of generator rotor during electromechanical transient process.Considering the fact that the Extended Kalman Filter (EKF) has poor tracking accuracy and even filter divergence because of the first-order linearization, a transient process dynamic state estimator is proposed in this paper, which combines the Particle Filter (PF) with the choosing rough sampling strategies to prevent sample degradation. Finally, the EKF-based dynamic state estimation, unscented Kalman filter(UKF) and EKPF are achieved respectively on the three-machine nine-bus system of American West Grid (WSCC). Simulation has proved the effectiveness of the EKPF algorithm, and that the filtering performance during electromechanical transient process is obviously superior to the other two methods.

Study on the Improvement of Direct Power Supply Capability on the 10 kV-side of 220 kV Substation

CHENG Zhenggang, HUO Yanping, XI Yunhua, LIANG Jie

2015, 48(11):  99-102.  DOI: 10.11930/j.issn.10.11930.2015.11.99

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Improving power supply capability has been a focus of study in the construction of substations in urban areas. According to the problems of urban substations, a new type of construction scheme of urban substation is proposed through improving the direct power supply capability on the10 kV side of 220 kV substation, which is aimed to optimize the location of the substations in urban areas. Based on a comparison among the proposed scheme, the conventional 220 kV substation scheme and the 220 kV substations scheme which exports in 20 kV, it can be concluded that the proposed scheme is suitable for planning and construction of 20 kV substations in the urban area with high load density. Finally, a case study is conducted on a 220 kV substation in Guangzhou, which may provide references for the construction of substation in urban areas.

New Energy

Analysis on Low Voltage Ride Through of Doubly Fed Induction Generator with Different Crowbar Control Strategy

WANG Jifei，, LI Peiqiang, LI Xinran, GU Zhen, QIU Shiyan

2015, 48(11):  103-109.  DOI: 10.11930/j.issn.10.11930.2015.11.103

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The crowbar protection circuit is frequently adopted to implement low voltage ride through (LVRT) of the grid-connected doubly fed induction generator(DFIG). In order to effectively evaluate DFIG transient behavior, the stator and rotor short-circuit characteristics after crowbar switched in during a grid fault is analyzed in detail. The range of crowbar resistance is also discussed. The DFIG modal containing crowbar protection circuit is built up in PSCAD/EMTDC. An evaluation index function of dynamic response is presented. The analysis of simulation results reveals optimal crowbar control strategies for LVRT under different grid voltage drop.

Coordinated Control of DC Microgrid Based on DC Bus Signaling

ZHANG Huiqiang, WANG Yutuo, WANG Linchuan

2015, 48(11):  110-116.  DOI: 10.11930/j.issn.10.11930.2015.11.110

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For microgrid systems with renewable energy generation, DC microgrid becomes a new hotspot for its significant advantages. Based on DC Bus Signaling(DBS), a coordinated control strategy is proposed to simplify control structure and avoid communication line construction. The proposed method improves system architecture by adding microturbine control. After analysis of different operation modes of DC microgrid, priority level and output characteristics of each distributed energy source are designed to switch smoothly among different operating modes. Various operation mode simulation results in matlab/simulink show that proposed method has ability to realize coordinated control of DC microgrid．

Smart Grid

A Composite Green Energy Network Design Based on Electric Energy

LI Siwei, LI Shuquan

2015, 48(11):  117-122.  DOI: 10.11930/j.issn.10.11930.2015.11.117

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A composite green energy network design based on electric energy is described. The system eliminates traditional working mode which separates cold, heat and other isolated systems. The system is managed through combination of energy production, storage, consumption and controlling during whole lifecycle. Based on electric power, the energy system transport energy efficiently and have seamless two-way interaction with energy request and supply. Based on several smart grid technology, energy control and optimization are achieved in a park that has different types, quality requirement of energy request and supply.

Review of Key Technology of Smart Grid Supporting Smart City Construction

LI Bo, GAO Zhiyuan, CAO Yang

2015, 48(11):  123-130.  DOI: 10.11930/j.issn.10.11930.2015.11.123

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Smart grid has great supporting potential for smart city construction. This paper describes the connotations, characteristics of smart city and its key demands for smart grid. It is pointed out that smart grid is an important component of smart city after a careful study of the relationship between smart city and smart grid. It is the important way to develop smart city by constructing smart city based on smart grid. The key technological problems to be solved for the development of smart grid reside in fields of information and communication technology (ICT), distributed generation (DG) integration, energy storage, active distribution network (ADN), demand response (DR), electric vehicle to grid, energy internet etc. It is concluded that the smart grid will effectively promote smart city construction.

Energy Conservation and Environmental Protection

Analysis of Primary Air Pollutant Emission Characteristics and Reduction Efficiency for Ultra-Low Emission Coal-Fired Power Plants Based on Actual Measurement

SHUAI Wei, LI li, CUI Zhimin, WU Jiayu, MO Hua

2015, 48(11):  131-137.  DOI: 10.11930/j.issn.10.11930.2015.11.131

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In this paper, take the example of a coal-fired power plant located in the eastern coastal major control zone defined in the “12th Five-Year Plan of air pollutant control in major regions”, where ultra-low emission technique is implemented including low NOx combustion +SCR+low-low temperature electrostatic precipitator(ESP)+ wet desulphurization+ wet ESP, its primary air pollutant emission characteristics and environmental benefits are explored based on the existing measurement monitoring methods and standards of the country. The measurement results show that when firing the coal of sulfur contents no more than 0.75%, ash contents no more than 16.2% and low calorific values more than 21.87 MJ/kg, according to the hourly average evaluation method, under 100% and 75% load conditions, the maximum emissions of NOx, SO2, dust and mercury with its compounds are 35.44 mg /m3, 17.11 mg/m3, 9.30 mg/m3 and 2.19 μg/m3 respectively, which comply with the requirements of ultra low emission. In addition, the SO3, PM2.5 and droplet emission concentrations are controlled under 3.5 mg/m3, 0.3 mg/m3 and 27.6 mg/m3, the PM2.5 removal rate of wet ESP is more than 70%, which means that the ultra-low emission technology is helpful for the pollutants emission reduction from the power plant. However, the emission reduction costs associated with the technologies are relatively high. Furthermore, the current measuring methods cannot fulfill the requirements of low concentration measurement. Therefore, it is suggested that new technical specifications on ultra-low pollutants should be put forward as soon as possible.

Retrofit for SCR Equipment Operation Rate Improvement under Low Load Conditions on 600-MW Supercritical Boiler

LUO Jiangyong, LV Xinle

2015, 48(11):  138-141.  DOI: 10.11930/j.issn.10.11930.2015.11.138

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In this paper, the case study is conducted on the first economizer retrofit project which is for the improvement of the SCR equipment operation rate under low load conditions on a supercritical boiler. The continuous two-month operation monitoring shows that the project is feasible in ensuring the SCR operation rate under low load conditions, and furthering lowering the exhaust gas temperature at the same time. The project provides a reliable reference for upgrading the SCR denitrification equipments in other power plants.

Technology and Economics

Substation Life Cycle Cost Prediction Model of the Least Squares Support Vector Machine Optimized by Genetic Algorithm

QIAO Guohua, GUO Luyao, Wu Yidi, LI Jing, JIA Zhaoyang, HAO Feng, ZHAN Xiangling, WANG Yayun

2015, 48(11):  142-148.  DOI: 10.11930/j.issn.10.11930.2015.11.142

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Because of large number of equipment and investment during substation construction, building a reasonable life cycle cost (LCC) prediction model is an important means of improving grid assets management efficiency. The methods to ensure convergence capability and improve prediction accuracy are difficulties in current study. A substation LCC prediction model based on least squares support vector machine optimized by GA is proposed. The method use some representative indexes as predictive model input vectors and the total substation LLC cost as the output vector. The results from traditional LS-SVM prediction model, BP neural network prediction model and GA optimized LS-SVM prediction model are compared on selected examples. The comparison verifies superior performance of proposed model. The proposed method can be used during new substation planning and construction to predict station LLC quickly and efficiently.

Study on Distribution Network Investment Allocation and Project Selection Optimization

CUI Wenting, LIU Hong, YANG Weihong, WANG Xuyang, JI Shiyu

2015, 48(11):  149-154.  DOI: 10.11930/j.issn.10.11930.2015.11.149

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With fast development of distribution network, there are several problems appeared, including fund allocation difficulty in provincial power grid, investment imbalance in city power grid, lack of clear evaluation and selection criteria for distribution projects. A practical method of distribution network investment allocation and project selection optimization method is proposed. Firstly, an operating status improvement assessment system for project group and single project basing is built based on analysis of influencing factors. Secondly, an investment allocation model for funds allocation of provincial power grid company is proposed, considering the project group evaluation results, as well as distribution network level, scale, operation level and profitability, in order to calculate investment allocation ratio of municipal power grid companies. Then, with constraints of investment limits for municipal power grid companies, projects optimal selection is performed based on the sorting of single-project evaluation and project investment results. The case study results demonstrated the effectiveness of proposed method.