Table of Content

05 February 2019, Volume 52 Issue 2

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Progress of the Full Load Test of the Gasification Unit in IGCC Power Station

LI Haiming, WANG Xiangping, FU Bin, WU Ping, YU Yang, BU Xinzhan, WEN Ziqiang

2019, 52(2):  1-6,103.  DOI: 10.11930/j.issn.1004-9649.201804130

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Huaneng (Tianjin) IGCC (Integrated Gasification Combined Cycle) demonstration power station is the first IGCC station in China. The core device in the power station is the two-stage dry fine coal gasifier which is designed and manufactured by China independently. In order to debug the unit in depth, Tianjin IGCC power station carried out the full-load test of the gasification unit, after solving the problems of operation instability, burner cover leakage and equipment malfunction, and completing the heavy load test of the gasification unit. Through comparative analysis, the full-load test of the gasification unit has testified the stability of the system. Meanwhile, some potential problems of the system have been found. The test has enabled the accumulation of valuable data and experience for further amplification and improvement of the unit.

Study on Typical Domestic and Foreign IGCC Technology Applications

REN Yongqiang, CHE Defu, XU Shisen, LI Xiaoyu, TAO Jiye, LIU Gang

2019, 52(2):  7-13,184.  DOI: 10.11930/j.issn.1004-9649.201806062

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As the coal power still remains dominant in China's current energy structure, the highly efficient and clean IGCC technology has demonstrated a wide application prospect in China. In this paper, the process flow of air separation technology, coal gasification, the high-temperature purification, and combined cycle technologies of five typical IGCC power plants with installed capacity greater than 250MW are analyzed. Particularly, the overall objectives, development stages as well as system parameters and the operation of the Tianjin IGCC project are described, which is expected to have certain reference value for the future development of IGCC technology in our country.

Performance Optimization of the IGCC Gas Turbine Fueled with Low Heat Value Syngas

GUO Lei, SONG Wenzhe, WANG Xiangping, YU Yang, WANG Erxin

2019, 52(2):  14-19.  DOI: 10.11930/j.issn.1004-9649.201711165

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Tianjin IGCC is the first integrated gasification combined cycle plant in China, where the gas turbine burns the lower heating value syngas produced by the gasifier. As the first gas turbine coupled with IGCC technology in China, it has encountered many problems during operation such as the discrepancies between the heat value of syngas and design value, the burner overheating and the uneven burning of the two combustion chambers. To solve these problems, this paper introduces and explains the differences between the IGCC gas turbines and regular gas turbines in the aspects of fuel, combustion method and burner structure. Then, combined with the analysis on the actual operation parameters, the performance optimization plan and corresponding measures are put forward. It is of referential significance for the subsequent development of gas turbine burning low heat value fuel.

Engineering Application and Demonstration of Control System for IGCC Power Station

WANG Jianzhao, ZHONG Yiqing, SUN Yangyang, ZHOU Xian

2019, 52(2):  20-25,45.  DOI: 10.11930/j.issn.1004-9649.201807111

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Taking an IGCC power station in China as the research object, based on its operation behavior and control requirements, the design of the coordinated control system and its composition, the load command, as well as the control strategy of the gasification furnace and gas turbine are presented in this paper. The load control scheme with the gasifier control as the primer and gas turbine/turbine as the follower is proposed. The field operation shows the simplicity and effectiveness of the scheme. The IGCC unit control requirements can be fully satisfied.

Study on Water Gradient Utilization and Zero Emission Technology in IGCC Power Plant

WU Huoqiang, YUAN Guoquan, LIU Yapeng, WANG Xiangping, WANG Jing, LI Xiangjun, WU Zhihong

2019, 52(2):  26-33.  DOI: 10.11930/j.issn.1004-9649.201802048

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In the first IGCC power plant in China, there are some problems in the operation process such as the water drainage process is not reasonable and the coal gasification and sulfur containing wastewater is difficult to deal with. In view of these problems, this study proposes the water gradient utilization and zero emission scheme. Through the systematic analysis and diagnosis of the current situation of IGCC power plant's water utilization and drainage, especially the operation of the wastewater treatment system, a detailed update plan is proposed. The main contents are as follows:(1) Low-salt waste-water and high-salt wastewater should be collected and reused separately; (2) The update schemes of domestic sewage, coal gasification wastewater, chemical desalted water, and terminal waste water treatment are proposed separately. Especially for the special gasification and sulfur containing wastewater of the IGCC power plant, a new treatment process is proposed. Through the upgrade of the above water gradient utilization and zero emission scheme, the zero emission of the whole plant wastewater can be realized, and the water intake for unit power generation is reduced from 1.51m³/(MW h) to 1.01m³/(MW h).

Residents Demand Response Strategy Considering Rolling Evaluation

SUN Yi, LIU Changli, LIU Di, LI Bin, JING Dongsheng, CHEN Songsong

2019, 52(2):  34-45.  DOI: 10.11930/j.issn.1004-9649.201805179

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Carrying out demand response can effectively stabilize the load fluctuation and reduce the difference between peak and valley load power consumption. However, the uncertainty of user response has greatly hindered the development of demand response service. For this reason, a research is made on the residential demand response strategy considering rolling evaluation, which is relied on the aggregate-centered demand response architecture, and supported by the baseline loads power deduction, with consideration of the implementation characteristics of real-time state, satisfaction and automatic demand response of users. A response evaluation model is established, and the rolling evaluation method is used to select predictable users to participate in the business in descending order according to the evaluation results, so as to minimize the uncertainty of the automatic demand response for the participation of residential users. Simulation results show that the strategy can save the demand side resources and reduce the response errors of user group.

Analysis on Foreign Typical Market Mechanisms for Promoting New Energy Consumptive

LI Guodong, LI Gengyin, ZHOU Ming, ZHANG Fan

2019, 52(2):  46-52,60.  DOI: 10.11930/j.issn.1004-9649.201802028

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China power grids are plagued by new energy consumption problems, due to power structure, power transmission capacity, new energy installed capacity growth, which have led to the increasingly prominent growth of China wind and photo-voltaic curtailment. Firstly, it analyzes main reasons to cause Chinese new energy consumptive problem. Then based on summarizing 2 kinds of consumptive methods, including indemnificatory new energy consumptive and market oriented method, it introduces 5 kinds of typical abroad market mechanisms to promote new energy consumptive, including new energy power forecasting, electricity deviation mechanism, peak load regulation mechanism, inter-regional and inter-national consumptive mechanism and renewable energy quota system. Combined with above abroad market mechanisms, it analyzes current market mechanisms situation of new energy consumptive in China. Finally, 5 specific recommendations to new energy consumptive in China are put forward, including forecast level, establishment of market mechanisms, electricity deviation processing, peak load regulation ancillary service and consumption scope expand.

Analysis on Improved Transmission Use of System Charging Methodology in UK

XIAO Jiang, LIU Ruifeng, JING Zhaoxia, HE Yuankang

2019, 52(2):  53-60.  DOI: 10.11930/j.issn.1004-9649.201806088

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Reasonable transmission pricing is an important basis for the construction of the electricity market. The improved transmission network use of system (TNUoS) charging methodology in UK is studied in this paper. The paper reviews the process of the transmission pricing reform in UK, summarizes the differences between the transmission pricing mechanisms before and after the improvement, and analyzes the improved DCLF ICRP model. The improved model is applied by using the example of 7-bus and IEEE 14-bus system, and it's effectiveness in guiding the generator and load investment is analyzed. Compared with the methodology before improvement, the improved methodology can effectively distinguish the TNUoS tariff of different power generation technologies, and promote the development of renewable energy, which can provide reference for the transmission and distribution pricing in China.

A Source-Grid-Load Coordinated Planning Model Considering System Flexibility Constraints and Demand Response

ZHANG Ning, DAI Hongcai, HU Zhaoguang, SHEN Bo

2019, 52(2):  61-69.  DOI: 10.11930/j.issn.1004-9649.201805017

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In the recent years, the problem of wind power curtailment has becoming increasingly serious in China. Hence it is urgent to improve the existing power system planning approaches. Considering the current situation that power system flexibility is not capable of meeting the requirements of wind power integration, in this paper the peak load regulation capacity constraint and regulation speed constraint are designed in power system planning model. Besides, this paper analyzes the multiple impacts of demand response on power systems and seeks the solution to incorporate them into the planning model. Then, a source-grid-load coordinated planning model is proposed, in which generation units, transmission lines and demand side resources are planned jointly. Through the case studies the effectiveness of the model is verified.

Construction and Application of Knowledge Graph of Power Dispatching Automation System

LI Xinpeng, XU Jianhang, GUO Ziming, LI Junliang, NING Wenyuan, WANG Zhenxue

2019, 52(2):  70-77,157.  DOI: 10.11930/j.issn.1004-9649.201804114

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The knowledge of power dispatching automation system is mostly scattered in the source code, configuration files, database and expert experience, and people can't get the whole business logic of the system. To solve this problem, a method is proposed in this paper to build a knowledge graph of the power dispatching automation system. Three steps, including knowledge acquisition, knowledge storage, and display and application of knowledge graph, are proposed to analyze the structured and semi-structured data sources, and get the relationship between the basic platform and various business, and to form the system structure and detail business knowledge. The constructed basic platform of power dispatching automation system and the knowledge graph of business logic can help to understand the business relationship of the whole system and facilitate fault analysis when system fault occurs.

Two-Stage Optimal Dispatching of Wind Power-Waste Incineration Virtual Power Plant with Flue Gas Storage Device

ZHOU Renjun, CHEN Yi, YANG Weiwei, WANG Yangzhi, XU Jian, ZHU Jiangsheng

2019, 52(2):  78-84.  DOI: 10.11930/j.issn.1004-9649.201806147

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The energy consumption for the flue gas treatment in the waste incineration power plant accounts for a large proportion of the plant's total power output, and its on-grid output is constrained by the coupling relationship between the power generation and the flue gas treatment. The relationship between the above two factors is decoupled through the installation of gas storage devices and controlling of the flue gas treatment time, so as to improve the flexibility of the waste incineration power plant in power output adjustment for grid-connection of large-scale wind power. The wind power plant, waste incineration power plant and the flue gas treatment system added with gas storage devices are integrated into a virtual power plant. Aiming at maximizing the overall net benefit, a day-ahead-real time two-stage optimal dispatching model is established, which includes the sub-model of flue gas treatment system with gas storage device. By using the day-ahead dispatching results as the report output, the amount of flue gas in the gas storage device is adjusted according to the deviation of actual and forecasted wind power output, and the net output of the waste incineration power plant is corrected in real time in order to follow the changes of wind power. Simulation results have verified the rationality of the proposed model, and the model has significant economic and social value in practical application.

Fast Simulation Platform of MMC Suitable for Multi-case Optimization Design and Repetitive Simulation

ZHOU Guoliang, XIE Zhujun, XIANG Wang, HE Yongjie, PENG Kaijun, LIANG Yanqiao

2019, 52(2):  85-93.  DOI: 10.11930/j.issn.1004-9649.201801106

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Aiming at the problem of the low simulation speed of MMC on PSCAD/EMTDC platform and the low efficiency of optimization design and repetitive simulations under different operating conditions, a Matlab-based fast simulation platform of MMC is constructed using M-language, which is solved using the Dommel algorithm and the trapezoidal integration method respectively for the electrical part and the control part. The modelling methods of the main electrical components with the Dommel algorithm are introduced, and the solving method for the electrical parts and the unified solving methods for the electrical part and control part are proposed. The simulation result of the proposed platform in this paper is compared with that of the PSCAD/EMTDC-based MMC modelling program, which has verified the correctness of the new fast simulation platform. The proposed simulation platform can be used as the core driver for MMC study such as the power loss calculation and overvoltage calculation, where repetitive simulations are required under different operating conditions.

Research and Application of Comprehensive Algorithm of Relay Protection Status Assessment Based on Gray Correlation Analysis and TOPSIS Method

YANG Guosheng, DAI Feiyang, WANG Wenhuan, GUO Peng, LI Yanfei

2019, 52(2):  94-103.  DOI: 10.11930/j.issn.1004-9649.201801178

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At present, the state evaluation for relay devices is too simple, subjective and inconvenient. To make the state evaluation of the relay devices more accurately reflect the state of targeted devices and provide more comprehensive information, a comprehensive evaluation system is established for relay protection and a whole-cycle multi-dimension on-line assessment method is proposed based on combined evaluation methods. Considering the operation conditions of protective devices over the recent years and on the basis of the randomness, fuzziness, importance and feasibility of current assessment method, the fuzzy mathematics theory, TOPSIS method and variable weight analysis method are introduced to optimize all aspects of the protection evaluation work with combination of the cloud method to ensure the objectiveness of the evaluation result. The case study has proved the effectiveness of the proposed method.

Operation State Evaluation of Distribution Network Based on Attribute Mathematics

HUANG Jianyong, MENG Qibin, WU Shunchao, SHI Hui, MA Shushu

2019, 52(2):  104-110,118.  DOI: 10.11930/j.issn.1004-9649.201711031

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With the development of social economy, it is urgent to realize self-healing control of distribution network to meet the increasing demand of electricity users on distribution network. The real-time and accurate control of the distribution network operation state is the premise of self-healing control of the distribution network. Firstly, the operation state evaluation indices are established from 5 aspects, including safety, reliability, quality, economy and adaptability; Then, a operation state evaluation model of distribution network is constructed based on the attribute mathematics theory, which can transform the operation state evaluation issue into the attribute measure calculation issue of the distribution network operation state; Finally, the analytic hierarchy process is used to determine the weight of each index, and the process is provided for solving the operation state evaluation model of the distribution network. Simulation results show that the model can accurately and objectively evaluate the running state of distribution network.

Application of KLU Sparse Direct Linear Solver in State Estimation

LUO Yuchun, WANG Yi, SHAN Xin, ZOU Dehu

2019, 52(2):  111-118.  DOI: 10.11930/j.issn.1004-9649.201806130

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Solving sparse matrix and linear equation is an important computational kernel in large-scale power system state estimation. This paper embeds the BTF and Gilbert-Peierls algorithm-based KLU sparse direct linear solver into the state estimation program of smart grid operation supporting systems. Firstly, based on the computation of the measurement jacobi matrix, the OpenMP parallelization technology is used to solve G which called gain matrix; and then, symbolic analysis and numerical factorization of G are handled by KLU solver; finally, the KLU solver is used to solve the linear equations in the process of state estimation, thus significantly improving the computational efficiency of state estimation in large-scale power network. The effectiveness and practicality of the proposed method are verified through practical application in D5000 system of provincial power company and model data dispatch centers.

Analysis of Development Efficiency and Regional Differences in China Power Grid Industry

LU Qiang, LIU Jin, JIANG Dongfang

2019, 52(2):  119-124.  DOI: 10.11930/j.issn.1004-9649.201805137

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The development efficiency and regional differences of power grid industry directly affect and determine the transition progress of China electric power industry and social economy toward high quality development. The data from 27 provincial power companies subordinated to State Grid Corporation of China for the period of 2010-2016 are taken as the research samples. Then the development efficiency and regional differences of power grid companies are theoretically explored and empirically analyzed from both overall and regional perspectives based on DEA-Malmquist index model. The results show that within the sampled period, the total factor productivity of China power grid industry is generally at a relatively high level, but a gradual declining trend has appeared slightly, mainly due to the slowdown in the rate of technological progress. Specifically, Beijing, Tianjin, Shanghai, Jiangsu and Shaanxi are on the rise, Zhejiang, Hunan, Chongqing, Liaoning, Jilin and Xinjiang remain stable, while other provinces are on a downward trend. Significant regional differences are also observed between the six major divisions of North China, East China, Central China, Northeast China, Northwest China, and Southwest China.

Method for LV Distribution Network Topology Verification Based on AMI Metering Data

YAN Weiguo, WANG Gaomeng, LIN Jikeng, GUO Lingxu, JIANG Ling, CHEN Jian

2019, 52(2):  125-133.  DOI: 10.11930/j.issn.1004-9649.201805105

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Aiming at the problem of topology error identification in low voltage distribution network, a method is proposed for low voltage (LV) distribution network topology verification based on AMI metering data. Based on the loads measurement information and network data provided by the advanced measurement system, the method firstly calculates the voltage at the coupling node and the associated branch current of each load under the same distribution, and then separately calculates the correlation coefficients of the coupling node voltages and the branch currents among all the loads for correlation analysis. In this way, the highly correlated loads falls into the same feeder, consequently determining the feeders to which each load belongs. According to the magnitude of the voltage of the coupling nodes of the loads, the upstream and downstream relationships of each load in the same feeder are determined. Finally, the load of the error connection is corrected based on the correlation analysis results and the voltage distribution of the coupling nodes of the load. The topology verification and correction of the LV distribution network are thus completed. The case study has verified the feasibility and effectiveness of the proposed method.

Partial Discharge Experiment Research under Simulated Defect of Real Switch Cabinet

FAN Min, YE Huisheng, DUAN Xiaoli, HUANG Haibo

2019, 52(2):  134-138,143.  DOI: 10.11930/j.issn.1004-9649.201804075

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Most of the live detection data of switch cabinet are indirect state quantities, which can hardly reflect the partial discharge values of switch cabinet and may easily cause erroneous judgment of defects. Therefore, a defect simulation test device is set up based on a real switch cabinet. Firstly, it is used to simulate the needle plate discharge. Then, the characteristics of needle plate discharge are identified through comparing the results of such detecting methods as acoustic emission, transient earth voltages, ultra high frequency and pulse current, including typical images of live detection signal and the relationship with PD values. Finally, subsequent research techniques for this device is put forward.

Further Research on Insulation Coordination of UHV Half-Wavelength Power Transmission Line

ZHANG Liuchun

2019, 52(2):  139-143.  DOI: 10.11930/j.issn.1004-9649.201801091

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Ultra high voltage half wavelength transmission (UHV HWACT) is a kind of transmission mode with large capacity and long distance, which has the advantages that it is not necessary to install reactive compensation devices of the line and to build switch substations, and will be widely used in China. Research results on insulation coordination will be the base of UHV HWACT technique applied to engineering construction. Firstly, this paper determined the continuous operating voltage, the rated voltage and the absorbed energy of the UHV HWACT lightning arrester; secondly, the line insulator configuration was determined by the design method of polluted external insulation, and the air gap distance was also determined; finally, research on insulation coordination was also carried out when considering power fluctuation.

Diagnosis on Failure of Dynamic Warping of Circulating Water Pump's Mirror Plate and Discussion on Vibration Evaluation

ZHANG Chu, YANG Yi, JIN GE, LIU Shi, GAO Qingshui

2019, 52(2):  144-148,177.  DOI: 10.11930/j.issn.1004-9649.201806017

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The unstable vibration on the 2nd harmonic has been existing in the pump-motor system, and the way to cool the motor has a significant effect on its vibration characteristics. Therefore, the field testing for this fault has been taken to diagnose and verify the failure of dynamic mirror plate warping of the motor under certain conditions. The analysis on the mechanism of the mirror warping failure concludes that it is the axial misalignment that leads to double frequency vibration. The concentration of the axial misalignment determines the dominant frequency of the operating equipment. The low-frequency vibration signal is amplified into the vibration displacement during the integration of the vibration velocity. At the end, it is suggested that the vibration velocity should be used to evaluate the vibration of the non-rotating parts of the low-speed equipment.

Study on Thermodynamic Performance of Volume Expanding Evaporative Solar System Hybrid with Coal Fired Power Generation System under Varying Radiations

FENG Lei

2019, 52(2):  149-157.  DOI: 10.11930/j.issn.1004-9649.201804054

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To avoid heat flux variations and non-uniform vapor-liquid distribution in parabolic collectors, the volume expanding evaporative solar steam generation system is proposed. Using actual solar radiation data from NASA SSE6.0 database, a 600 MW coal-fired power plant hybrid with a volume expanding evaporative steam generation system was established. Turbine stages at off-design condition were calculated with DNI data over a one-year period. And the daily, monthly and yearly thermodynamic performance of the hybrid system in Lhasa area was analyzed respectively. The results exhibit the same trends in steam mass flow, daily power generation and DNI with the monthly power generation reaching the maximum in June (2.95×10⁸ kW·h of electric energy produced), while the solar collector efficiency shows the opposite tendency. Moreover, the cycle thermal efficiency of power generation is relatively higher in summer, which typically ranges from 32% to 35% throughout the whole year. Annual solar thermal efficiency is approximately 22.5% by average. The results may provide a novel direction toward the application of solar energy system hybrid with coal-fired power generation.

Analysis on Rapid Cooling Technology in a 1 000 MW Steam Turbine and its Application

WU Xin, LI Lei, WANG Zhengming, MEI Long, SONG Yajun

2019, 52(2):  158-164,171.  DOI: 10.11930/j.issn.1004-9649.201806136

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In this paper, the natural cooling process of a 1 000 MW ultra-supercritical steam turbine is analyzed and its natural cooling time is determined. A rapid cooling scheme, which inhales air from the boiler, is designed. Based on the scheme, the rapid cooling of the steam turbine is successfully carried out, verifying the feasibility of the scheme. The results show that the rapid cooling can save a time of about 7 days compared with the natural cooling; meanwhile, to adopt the scheme of inhaling air from the boiler, the difference between the air temperature and the IP rotor temperature must be considered when determining the rapid cooling of the IP cylinder.

Analysis and Enhancement Study on the Cleaning Capacity of Plate-Frame Rotary Filter

WANG Jianjun, LI Junfeng, ZHANG Shoujie, HU Dingke, YI Qiang

2019, 52(2):  165-171.  DOI: 10.11930/j.issn.1004-9649.201805144

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Of all various filters that are vital to ensure the water quality for the nuclear power station, the rotary filter plays the most significant role in the cooling water source system. In order to improve the interception and decontamination capability and ultimately enhance the reliability of the cooling water source system of nuclear power station, three optimized design schemes are proposed based on the analysis and study of the existing plate-frame rotary filter:(1) Bucket-shaped reticulated frame; (2) Arc-shaped reticulated frame; (3) Combination of bucket-shaped and arc-shaped reticulated frame. The theoretical maximal values of the removal capacity with respect to the three mesh frame structures versus the original structure are provided. The results show that all three enhanced schemes can greatly improve the removal capacity of the rotary filter. To verify the theoretical calculation results, industrial tests were carried out on the three above schemes respectively by using the fiber balls and water-filled plastic balls to mimic the contaminants to be intercepted. The testing results were basically consistent with the theoretical calculation results. In addition, the bucket-shaped and arc-shaped lattice frame composite structure has exhibited the strongest cleaning capacity.

Failure Analysis and Countermeasures of Double Tower Double Cycle Desulfurization Demister

LI Zhuang, HU Da, ZHU Yue

2019, 52(2):  172-177.  DOI: 10.11930/j.issn.1004-9649.201805056

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As one of the most critical equipments in wet flue gas desulfurization system, the performance of the demister will directly affect the operation security of the desulfurization system and even compromise the generation unit itself. This paper took the failure scenario of the double tower double cycle desulfurization of a 660 MW coal-fired unit as an example, in which the blockage of demister caused overturn fault on some modules. The comprehensive analysis was also conducted regarding the demister design factors (such as the air velocity within the cooling tower, the mounting space, the pressure of flush water etc.), the concentration of entrance smoke, the rinse water volume of demister as well as the components of slurry, gypsum and fouling materials. It was found that the improper water balance control of desulfurization system and the high pH value settings of the secondary tower were the major culprits of demister failure. In order to reduce the risk of operation failure of the demister, some reasonable suggestions were given for the control of water balance and slurry pH value of the double tower double cycle desulfurization system.

Analysis and Treatment of Ash Deposition in SCR Denitration Equipments of W Boiler

WANG Fangyong, LI Wenjie

2019, 52(2):  178-184.  DOI: 10.11930/j.issn.1004-9649.201802027

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The W type flame boiler in a power plant is burned with high ash anthracite. The serious ash accumulation on the SCR denitrification reactor catalyst, the diversion plate, the rectifying grille and the supporting steel beam can lead to the uneven flow of the flow field and the blockage of the catalyst, which affects the performance of the SCR denitrification system. According to the operation experience and the CFD technology, the reasons for the ash accumulation in the SCR denitrification devices are improper design, unreasonable catalyst type selection, uneven flow field, poor soot blowing, long term low load operation and coal ash far beyond the design value. Based on the optimization of the flue gas flow field and the 1︰10 physical model test, the diversion plate, the rectifying grid and the top flue were reformed; the honeycomb type catalyst was replaced by the plate type catalyst; and the sonic soot blower was added. Three months after the transformation, the internal inspection of the denitrification devices was carried out. The horizontal flue of the reactor and the ash accumulation of the diversion plate were reduced obviously. No ash accumulation was found in the rectifying layer. No accumulated ash and blockage were found on the surface of the catalyst and the. It is proved that the measures taken have solved the problem of the internal dust accumulation and the catalyst plugging in the SCR reactor effectively.