Table of Content

05 October 2018, Volume 51 Issue 10

Previous Issue    Next Issue

Study on the Concept of the Smart Power Plant and Its Architecture Model

ZHANG Jinbin, ZHOU Siwei

2018, 51(10):  2-7,42.  DOI: 10.11930/j.issn.1004-9649.201808001

Asbtract ( )   PDF (7560KB) ( )  

References | Related Articles | Metrics

The smart power plant is defined in this paper based on the analysis of the definitions of some existing smart entities. The development of the artificial intelligence technology and the features of the power plants are taken into consideration as well. The architecture model for smart power plant is proposed after analyzing the RAMI4.0 and China Intelligent Manufacturing Architecture. Also, the ISO enterprise life-cycle process, Purdue enterprise reference architecture, and the CPS technology are referred to as reference.

Key Technologies for Intelligent Coal-Fired Power Generation

HUA Zhigang, GUO Rong, WANG Yong

2018, 51(10):  8-16.  DOI: 10.11930/j.issn.1004-9649.201808022

Asbtract ( )   PDF (5320KB) ( )  

References | Related Articles | Metrics

Intelligent power generation technology is an important means to promote the competitiveness of coal-fired power plants in power generation field. The policy and industrial background of the intelligent coal-fired power generation are analyzed in this paper, and the architecture of the intelligent coal-fired power generation technology is proposed by considering the intelligent equipment layer, the intelligent operation and maintenance layer and the intelligent management layer of the smart power plants. Six key technologies of intelligent coal-fired power generation are presented, including the smart measurement and control, the smart operation optimization and energy conservation, the life cycle equipment management, the intelligent robot technology, the intelligent operation and management, the intelligent interaction and security, etc. The latest progresses are summarized and can be used as a reference for the future development of the intelligent coal-fired intelligent power generation.

Construction Planning and Technical Route for Thermal Power Plant Intelligentization

GUO Weimin, ZHANG Guangtao, LI Bingnan, LIANG Zhengyu, ZHU Feng, TANG Yaohua

2018, 51(10):  17-25.  DOI: 10.11930/j.issn.1004-9649.201808096

Asbtract ( )   PDF (4872KB) ( )  

References | Related Articles | Metrics

In order to be adapted to the changes in the competitive situation of the power market and the rapid development of related technologies such as artificial intelligence, the construction of intelligentized thermal power plants has become a research hotspot inside and outside the industry as a relatively independent research and innovation field. However, there still exist many problems and challenges in the aspects of concept, technical routes and implementation strategies. On the basis of reviewing the development process of automation and intelligentization of thermal power plants in China and abroad, combined with the development status and trends of thermal power plant control technology and information technology, the definition and technical characteristics of intelligent thermal power plants as well as the architecture of intelligent thermal power plants are described in this paper. Besides, the key technical routes for the intelligent construction of thermal power plants are expounded from the aspects of the two main aspects, i.e., operation optimization and maintenance. Finally the potential problems that may be encountered and corresponding countermeasures in the construction of intelligentized thermal power plants are pointed out.

Parallel Intelligence and Smart Energy: Social Energy Technology with Human Factors Incorporated

ZHANG Jun, WANG Feiyue, LIN Jieyu

2018, 51(10):  26-31.  DOI: 10.11930/j.issn.1004-9649.201808046

Asbtract ( )   PDF (5053KB) ( )  

References | Related Articles | Metrics

With the integration of new energy resources and the increased power demands for both quantity and quality, Chinese power grid faces a series of new challenges. Within the framework of Energy 5.0, this article provides our perspective on the social energy technology with human factors fully incorporated. This article discusses the technical framework and application examples in the power supply side, transmission side, distribution side and demand side, specifically, including the intelligent power generation coordination using parallel perception and virtual system technology, the intelligent auxiliary decision-making for power dispatch using speech recognition and semantic analysis, and the demand side management using social energy and parallel intelligence technology. We aim to equip power systems with the capabilities of human-system interaction, artificial intelligence aided auxiliary decision making, self-learning, and demand side management with self-adaptation to volatile renewable energy generation.

Architecture of the Intelligent Power Generation Technical Specification for Electric Power Enterprises

CUI Qingru, LI Gengda, NIU Yuguang

2018, 51(10):  32-36,48.  DOI: 10.11930/j.issn.1004-9649.201808021

Asbtract ( )   PDF (7283KB) ( )  

References | Related Articles | Metrics

The rise of the fourth industrial revolution prompts significant changes in the energy sector. The intelligent power generation is an important direction of the technology transformation for power generation enterprises. Based on the planning of intelligent power generation in electric power enterprises, the ideas and contents of the technical specification compilation are explained with the focus on the intelligent thermal power generation technology. The framework of the intelligent thermal power generation technology composed of the operation control system and the public service system from the view of function implementation is presented. The functional requirements and application principles that can be used to guide the practice are proposed as well. At the same time, by considering the characteristics of other power generation forms, the technical specifications for intelligent wind, photovoltaic and hydro power generation are introduced briefly. Finally, it puts forward some deep thoughts and suggestions on the construction of intelligent power generation for power enterprises.

The Architecture and Design of the Autonomous Object Oriented APS2.0 System

YIN Feng, CHEN Bo, DING Ning, WANG Jianping, DING Yongjun

2018, 51(10):  37-42.  DOI: 10.11930/j.issn.1004-9649.201808024

Asbtract ( )   PDF (4907KB) ( )  

References | Related Articles | Metrics

As an important part of the power plant intelligence, APS technology is facing the low usage rate problem. In this paper, the object-oriented APS2.0 system structure and design method are proposed to replace the traditional procedural-oriented design concept. Starting from the construction of autonomous object system and the enhancement of human-machine collaboration, the new system guides the operators to change their operating habits and establishes their system operation concepts. Thereby the system utilization and the unit automation level can be improved. The Design includes the intelligent optimization, the interface with the external intelligent auxiliary system and the application structure. The operational data are collected and accumulated as well. All of these may give a broder way for the further application of the intelligent technology. Furthermore, the composition of the object system, the principles of the configuration design, the implementation of the application, and the management of the system failure and safety are described in details to demonstrate the new technical idea.

Optimized Control Technology for Start-up Process of Thermal Power Units Based on Intelligent Algorithm

ZHU Xiaoxing, XUN Xin, CHEN Houtao, WANG Zhijie, WANG Xihui, PENG Liang

2018, 51(10):  43-48.  DOI: 10.11930/j.issn.1004-9649.201808014

Asbtract ( )   PDF (4985KB) ( )  

References | Related Articles | Metrics

Based on the constraint conditions such as equipment status before the start-up of unit, the intelligent planning for unit start-up path is realized by mixed integer linear programming algorithm. Using the risk analysis method based on similarity measure of fuzzy numbers, the risk is forecasted for the start-up process of steam turbine. Furthermore, the automatic start-up control method independent of the thermal stress model is realized, which is applicable to all kinds of mainstream steam turbines. Based on the human-simulated intelligent control method, the intelligent fault elimination method and the automatic pipe warm-up method are put forward. From these applications it is shown that the control technology based on intelligent algorithm can reduce the labor strength of the operators, improve the unit's start-up process, and enhance the intelligent control level of thermal power unit.

Research on the Construction of Intelligent Power Plant of 1 000 MW Thermal Power Unit

HAN Huafeng, MA Yujuan, HUANG Yizhi, YANG Mengmeng, GUO Tao, LIU Ran, ZHANG Wei, SUN Yafei

2018, 51(10):  49-55.  DOI: 10.11930/j.issn.1004-9649.201712050

Asbtract ( )   PDF (5114KB) ( )  

References | Related Articles | Metrics

In recent years, the power market has faced many challenges such as overcapacity, variable load, excessive debt, environmental pressure and insufficient demand, which puts forward new and higher requirements for production, operation management and control capabilities of power plant. Combined with the 1 000 MW ultra-supercritical coal-fired unit of Fangjiazhuang Project, after extensive research, the construction concept of the intelligent power plant of Fangjiazhuang Project is proposed according to the connotation of the intelligent power plant, the intelligent power plant structure is formulated, the construction content of the intelligent power plant is determined, and the construction goal and effect are clearly defined, at last, a complete set of intelligent power plant construction plans is formed. By integrating Internet of things, cloud computing, big data analysis, artificial intelligence, robotics, virtual reality, mobile applications through technologies such as intelligent sensing and execution, intelligent control and optimization, intelligent management and decision-making, etc., the unit are more safer and reliable, and the operation are more economical and efficient, environmentally friendly and flexible, and the unit can better adapt to the competitive environment of the electricity market.

Research on Non-Isolated Bidirectional Four-Port DC-DC Converter and Its Control Strategy

CUI Hongfen, YAO Liangzhong, SANG Bingyu, YANG Bo, TAO Yibin

2018, 51(10):  56-63.  DOI: 10.11930/j.issn.1004-9649.201702043

Asbtract ( )   PDF (4812KB) ( )  

References | Related Articles | Metrics

The paper proposes a non-isolated four-port bidirectional DC converter based on bidirectional buck-boost converter, to accommodate the needs of power flow confluence, distribution and voltage conversion. The proposed DC converter enhances the efficiency and power density by achieving voltage step-up through a single process. Compared with the conventional practice where multi-port converters are connected with a common AC or DC bus, the proposed design sees reduction in both volume and costs and improvement in reliability by eliminating the DC capacitor and AC transformer. In the converter, any selected pair of input and output ports can be considered as a buck-boost unit, there is no coupling among different units in terms of power circuits. Therefore, it is easy to be realized. After analyzing the operational mechanism of the proposed DC converter, a four-terminal bipolar DC transmission system is established in PSCAD/EMTDC, to demonstrate and validate the effectiveness of the proposed DC converter. An example device is also developed for the purpose of further validation. Simulation results suggest that the proposed DC converter can perform the task of power flow distribution and voltage step-up.

Operation Optimization of DC Distribution Network with Multi-time Scale

YI Yue, YUAN Zhichang, ZHENG Hao, SHI Zinan, MA Weijing

2018, 51(10):  64-71.  DOI: 10.11930/j.issn.1004-9649.201706154

Asbtract ( )   PDF (3848KB) ( )  

References | Related Articles | Metrics

In order to realize the safe and reliable operation of DC distribution network, two operation optimization models of DC distribution network are established in this paper. Firstly, the objective functions of DC distribution network operation optimization are discussed. Aimed at the above objective functions, two DC distribution network operation optimization models are proposed:one is the real-time power flow optimization model with power loss and voltage deviation as the objective functions; the other is the day-ahead optimization model considering the source network load characteristics, with the daily operating costs and load variance as the objective functions of load shifting optimization. The solutions of the two models are given, and the two models are simulated in a 9-node DC distribution network. The simulation results verify the effectiveness of the models in improving the DC power flow distribution and load shifting.

Coordinated Control of Multi-HVDC Participating in Three Defense Line at the Receiving End of the Power System with Strong DC and Weak AC

YUAN Sen, CHEN Dezhi, CHEN Tao, TANG Wei, MA Shiying, LUO Yazhou, SONG Yunting, REN Jianwen, ZI Peng, WANG Qing, LI Zaihua

2018, 51(10):  72-79.  DOI: 10.11930/j.issn.1004-9649.201707120

Asbtract ( )   PDF (4137KB) ( )  

References | Related Articles | Metrics

Ultra high voltage direct current (UHVDC) is characterized by fast and flexible control, thus has been widely adopted to implement effective power control in power systems. It is of great significance to investigate the capability of UHVDC in power system risk defense. The potential risk of power system operation under the condition of weak AC and strong DC is analyzed, which is a typical engineering problem in China. Based on the analysis, the control strategies are proposed that involve UHVDC in the three-defense-line control at the receiving end of power systems, so as to counter the risk of DC blocking. The proposed control strategies include:pre-control of active power of UHVDC, coordinated control of UHVDC and load shedding, coordinated control of UHVDC and under-frequency load shedding in the occurrence of the breaking of weak AC connection. The validity of the proposed methods is verified by simulation.

Analysis and Suggestion for Distributed Photovoltaic Generation

PEI Zheyi, DING Jie, LI Chen, ZHOU Chang, LIANG Zhifeng, YU Hui, XU Xiaochun, ZHANG Jun

2018, 51(10):  80-87.  DOI: 10.11930/j.issn.1004-9649.201805089

Asbtract ( )   PDF (3912KB) ( )  

References | Related Articles | Metrics

In recent years, domestic distributed photovoltaic (PV) presents a high-speed development trend with the characteristics of wide-area and locally high-density parallel network, which brings impact to the operation safety of power grid in the high-proportion PV generation area. Based on the survey of a large number of data, this paper analyzes the distributed PV in 27 provincial power grids in China. Suggestions for promoting PV penetration are given in terms of changing distribution network characteristic, increasing power balancing difficulty, increasing voltage adjusting ability, and decreasing frequency adjusting ability.

Short-term Parallel Power Load Forecasting Based on Balanced KNN

LIN Fang, LIN Yan, LV Xianlong, CHENG Xingong, ZHANG Huiyu, CHEN Bojian

2018, 51(10):  88-94,102.  DOI: 10.11930/j.issn.1004-9649.201708078

Asbtract ( )   PDF (5428KB) ( )  

References | Related Articles | Metrics

To improve the accuracy of load forecasting and cope with the challenge of single computer's insufficient computing resource under massive and high-dimension data, a short-term load forecasting model based on balanced KNN algorithm is proposed. In order to improve the accuracy of scene division, the weight of load characteristics is quantified by using the anti-entropy weight method; According to the load characteristics, the historical data of massive power load are divided into scenes by the K-means algorithm; In view of unbalanced load scenes, the balanced KNN algorithm is proposed to classify the scene accurately; The BP neural network algorithm is used to train and predict the load; Adopting the Apache Spark programming framework of cloud computing, the proposed algorithm model is parallelized and improved to enhance its ability of dealing with massive and high-dimension data. The analysis of the household electricity consumption data for a residential district is done by 30-nodes cloud computing cluster, and experimental results show that the load forecasting accuracy and execution time by the proposed model are the better than those of traditional forecasting algorithm, besides, the proposed forecasting algorithm possesses excellent parallel performance.

Intraday Security-Constrained Economic Dispatch with Coordinative Optimization of Peak Regulation Ancillary Service and Unit Energy

LI Yanchun, ZHANG Huaqing, LIN Wei, LI Chengdong, BAI Yang, ZHANG Xiaohan, ZHAO Ran, ZHANG Kaixuan, WANG Yang

2018, 51(10):  95-102.  DOI: 10.11930/j.issn.1004-9649.201711125

Asbtract ( )   PDF (3574KB) ( )  

References | Related Articles | Metrics

The penetration of large-scale renewable energy brings great challenge to power system peak regulation, which makes it more difficult to balance the energy completion processes of different units under the current dispatch mode. Aiming at the intraday dispatch problem, an intraday dispatch mode with coordinative optimization of peak regulation ancillary service and unit energy is proposed, so as to avoid the collision between the peak regulation market mechanism and the current dispatch mode. Based on the proposed mode, the intraday security-constrained economic dispatch model is developed to realize the coordination of peak regulation ancillary service and unit energy as well as minimize the overall dispatch costs. To accelerate the computation of this model, an iterative algorithm featuring identifying the bidding security constraints is derived. Finally, the effectiveness and efficiency of the proposed models and methods are validated by the IEEE 30-bus system and a real-world provincial power system.

Novel SPDU Big Data Scheduling Algorithm Based on Grey Fuzzy Prediction

ZHOU Shengqi, JIA Yajun, ZHU Hua

2018, 51(10):  103-110.  DOI: 10.11930/j.issn.1004-9649.201708074

Asbtract ( )   PDF (2535KB) ( )  

References | Related Articles | Metrics

For the problems existing in smart power distribution and utilization (SPDU) data service system, such as big data size, difficult information retrieval and long span scheduling, a novel SPDU big data scheduling algorithm based on grey fuzzy prediction (SGFP) is presented. In order to address the data access bottlenecks and long span scheduling of SPDU big data systems, the SGFP utilizes the grey fuzzy methods to mine the requirements of clients and management personals, and to make pre-access and scheduling of the moving data in several data servers. The SGFP is tested in an interactive community client service system. The simulation result shows that compared to the traditional algorithms, the SGFP has better response speed and accuracy, as well as lower system resource cost.

Critical Node Identification for Electric Power Communication Network Based on Characteristics of Topology and Services

WANG Yang, GAO Hanxing, ZHOU Shengping, WANG Zhihui, HE Yujun

2018, 51(10):  111-118.  DOI: 10.11930/j.issn.1004-9649.201802016

Asbtract ( )   PDF (2269KB) ( )  

References | Related Articles | Metrics

The identification of critical nodes of the power communication network as well as the corresponding protection mechanism have crucial impacts on the system-wide reliability. In this paper, the Node Topology Importance (NTI) is obtained by calculating the rate of natural connectivity of power communication network after one node being destroyed. Then, an evaluation method is proposed according to the requirement of power communication network services. The weighted natural connectivity which fuses the node business information and topology information is defined, accordingly Node Combining Importance (NCI) is proposed to realize the excavation of key node. The effectiveness of the proposed methods is verified by case studies on a real-world regional power communication network.

Research on Ultra-Low Heat Dissipation Technology in Thermal Power Plants

JIANG Congjin

2018, 51(10):  119-122,129.  DOI: 10.11930/j.issn.1004-9649.201807112

Asbtract ( )   PDF (5741KB) ( )  

References | Related Articles | Metrics

In order to reduce the heat dissipation losses and save more energy in thermal power plants, by adopting the ultra-low heat dissipation technology, this paper calculates the insulation thickness, heat dissipation reduction, investment increase and investment recovery years of the main steam pipe with the external surface temperatures of insulation structure ranging from 50℃ to 30℃. By taking the newly-built power plant (2×1 000 MW) in Shandong Province for example, the investment in heat preservation is compared with respect to external surface temperatures of main steam pipe of insulation structure at 45℃ and 50℃. The results show that when the external surface temperature of the insulation structure declines from 50℃ to 45℃, the total volume of the insulation materials will grow, which will cause the increase of the investment by 300 thousand RMB yuan. Nevertheless, the temperature drop at the main steam cycle and the hot reheat steam cycle between the boiler outlet and the steam turbine inlet is reduced by 1 to 2℃ and thus the unit coal consumption is lessened by about 0.6 g/(kW·h). Therefore, substantial economic benefits is achieved for the power plants.

Study on Performance Testing Method and Emission Characteristics of Wet Electrostatic Precipitators

LI Haoran, LIU Hanxiao, ZHAO Lin, YAN Shijuan, FENG Guohua, FANG Xiaowei

2018, 51(10):  123-129.  DOI: 10.11930/j.issn.1004-9649.201805182

Asbtract ( )   PDF (4730KB) ( )  

References | Related Articles | Metrics

Due to the water film covered dust collecting electrode, the existence of water mist in the discharge area and the absence of vibration and secondary dust extraction, particularly its mechanism to agglomerate the fine particles significantly, the wet electrostatic precipitator (WESP) is very effective to reduce the emission of fine particles such as SO₃. Particulate matter is collected by integrated sampling head (built-in filter membrane), while PM2.5 is determined by gravimetric method (PM-10) and charge method (ELPI), and SO₃ is determined by condensation method or condensation method combined with isopropanol absorption. The results show that the concentration of particulate matter in different types of WESP varies from 2mg/m³ to 5 mg/m³, and PM_2.5 is lower than 3 mg/m³ with the dust removal efficiency around 75%~95%. Continuous spray is applied in the metal plate type wet electrostatic precipitator. Since there is no secondary dust of fine particles, the emission of particulate matter is kept below 1mg/m³. The emissions characterization of SO₃ in different types of WESP is generally below 5mg/m³, with the SO₃ removal efficiency about 60%~80%. The current density of conductive fiberglass WESP is generally greater than that of metal plate WESP, hence its SO₃ removal efficiency is generally higher.

Analysis of Performance for SCR Deactivated Catalyst before and after Regeneration

DU Zhen, WU Bo, YAN Min, ZHANG Yang, ZHU Yue

2018, 51(10):  130-133,138.  DOI: 10.11930/j.issn.1004-9649.201711088

Asbtract ( )   PDF (6018KB) ( )  

References | Related Articles | Metrics

In order to systematically study the performance of deactivated SCR catalyst for coal-fired power plant before and after regeneration, the microscopic characteristics of deactivated catalyst for a 330MW coal-fired unit are analyzed. The testing results show that after regeneration the active components of the catalyst after regeneration are effectively supplemented, and the catalyst activity is greatly improved. During the regeneration process, the sulfate salt deposition on the catalyst surface is eliminated and the weak acid and the strong acidity sites of the catalyst surface are enhanced, while the anatase phase of the catalyst is well maintained, and the microstructure of the catalyst is restored to a relaxed and even state. This proves that the catalyst regeneration method in terms of adding active ingredients and eliminating deposited salt can prolong the service life of the catalyst, and reduce the production cost of the power plant.

Discussion on the Comprehensive Utilization of Water Resources and the Technical Route of Pollution Prevention in Thermal Power Plants

YOU Liangzhou, HAN Qianqian, JIN Yinjia, ZHU Yue

2018, 51(10):  134-138.  DOI: 10.11930/j.issn.1004-9649.201708135

Asbtract ( )   PDF (3889KB) ( )  

References | Related Articles | Metrics

This paper analyzes the existing problems in water affairs management in 91 thermal power enterprises, and discusses the technical route of the water resources utilization and pollution prevention based on the current policies. The technical route is implemented in two steps. The first step is to optimize the water use of the whole plant by realizing the cascade utilization, the quality treatment and the reuse of water resources, and to minimize the wastewater of high salinity as well; the second step is the comprehensive treatment and transformation of the high salt wastewater, which cannot be reused, consumed and discharged, into the integrated wastewater treatment system. The waste water recycling can be realized through pretreatment softening, concentration reduction, evaporation desalination and solid waste disposal. It provides reference for the thermal power enterprises to explore the pollution prevention and comprehensive utilization of water resources.

Enhanced Mercury Removal Technology in Coal-Fired Power Plants Through Desulfurization Wastewater Evaporation

CHEN Kunyang, GUO Tingting, JIA Xibu, CAO Fan, YUAN Yuan

2018, 51(10):  139-144.  DOI: 10.11930/j.issn.1004-9649.201711270

Asbtract ( )   PDF (4008KB) ( )  

References | Related Articles | Metrics

It is difficult to treat Wet Flue Gas Desulfurization (WFGD) wastewater of coal-fired power plant due to its complex compositions. In this paper, take a 600 MW supercritical unit as the research object, desulfurization wastewater evaporation technology is used to enhance the removal of gaseous mercury (Hg) for coal-fired power plants and the feasibility of synergistic mercury removal is explored. Effects of desulfurization wastewater chlorine ion concentration and unit load on Hg removal were studied as well. The results show that WFGD wastewater evaporation is beneficial to improve the efficiency of Hg oxidation and removal because Hg enriched with chlorine ions is easier to be removed. Hence this method realizes WFGD wastewater zero discharge and simultaneously enhances Hg removal efficiency. In addition, the mercury removal efficiency is greatly affected by chlorine ion concentration in desulfurization wastewater. When the chlorine ion concentration was increased from 21 250 mg/L to 36 500 mg/L, the mercury removal efficiency dropped from 95% to 58%. The synergistic mercury removal performance is slightly lower compared with the high loading conditions.

Study on Online SCR Ammonia Slip Prediction Method

SONG Yubao, CHENG Shijun, YAO Yan, AN Dexin, JIN Lipeng, FANG Zhaojun

2018, 51(10):  145-149.  DOI: 10.11930/j.issn.1004-9649.201708302

Asbtract ( )   PDF (4208KB) ( )  

References | Related Articles | Metrics

The excessive ammonia injection due to the unreliable ammonia CEMS analysis result can cause high ammonia slip and severe ammonium bisulfate deposition on air preheater. On the basis of laboratory and field tests, a novel prediction method for ammonia slip considering the SCR reactor potential and deactivation tendency, is studied and presented. The application results on a 350 MW unit indicated that the ammonia slip could be predicted online based on the real-time DCS parameters, such as unit load, NO_x concentration inlet and De-NO_x efficiency, etc. With the predicted ammonia slip online, the ammonia flow injection can be adjusted properly to avoid excessive ammonia slip. Furthermore, the predicted ammonia slip value can be used for the early warning and decision making of lifetime management for SCR catalyst layer.

Study on the Simulation of Rotor Life Loss after Unit Load Shedding

WANG Lijian, HE Qing, LI Guoqing

2018, 51(10):  150-155.  DOI: 10.11930/j.issn.1004-9649.201711245

Asbtract ( )   PDF (4497KB) ( )  

References | Related Articles | Metrics

Due to the influence of the external power grid or the fault of the unit itself, the units in a power plant may suffer from severe operating conditions such as load shedding. To solve this problem, in this paper, a real-time evaluation method for rotor's life loss is proposed by analyzing the unit load shedding process. First, the dynamic model of steam turbine is established to simulate the load shedding process; then the rotor life loss is estimated by the established rotor life loss analysis module, and is applied to analyze the load shedding of a 1 000 MW ultra supercritical unit. When the unit sheds a load, its speed increases rapidly, and the loss of the rotor life increases with the increase of the speed. The analysis results show that the load shedding will inevitably lead to the life loss of the turbine rotor. Although the life loss caused by a single load shedding is small, the cumulative damage to the rotor life of the large capacity regulation units which shed load frequently is significant. Therefore, the turbine's rotor can be monitored in real time by this method to ensure its stable and secure operation.

Experimental Study on Corrosion Resistance of Two Kinds of Magnesium Oxide Fuel Additives Used in Heavy Oil-Fired Boiler

ZHU Hua, LIU Wenjian, YI Zezhong, MO Chunhong

2018, 51(10):  156-163.  DOI: 10.11930/j.issn.1004-9649.201708084

Asbtract ( )   PDF (4971KB) ( )  

References | Related Articles | Metrics

During the operation of oil-fired boiler, some problems occurs frequently such as high temperature corrosion of heating surface, ash deposition on heating surface, low temperature corrosion of air preheater and tail flue, and so on. Reasonable usage of magnesium oxide additive can effectively solve the above problems. Mechanisms, performance and application characteristics of above two kinds of fuel additives, i.e., Sunricho-EM330 and Sunricho-OM20 are introduced. In the heavy-oil fired boiler using fuels with high content of vanadium and sulfur, the two kinds of fuel additives are applied for the comparison test. The proper amount for the fuel additives are determined in test. Both of the additives have effect on anti-corrosion of heating surface, enhancing PH vale, and decreasing the dew point of flue gas. However, long term usage of additives will bring the fouling problem for the boiler as it could bring more ash. Heating surface inspection and ash analysis are performed when boiler is shut down. Sticky deposit is found in the inner layer of ash. To achieve the same target of anti-corrosion, OM20 exhibits more advantages with less amount of OM-20 needed but better performance in fouling.

Numerical Simulation and Optimization of Low NO_x Combustion Characteristics for a 600 MW Boiler

LI Ruping, FAN Yinlong, TONG Jialin, QI Xiaojuan, LÜ Hongkun, LI Jian, DING Liwei

2018, 51(10):  164-170.  DOI: 10.11930/j.issn.1004-9649.201806160

Asbtract ( )   PDF (4566KB) ( )  

References | Related Articles | Metrics

The problems of serious high-temperature corrosion and reheat steam temperature deviation have been in existence in a 600 MW subcritical boiler since its ultra-low NO_x combustion retrofit. In this paper, by virtue of numerical simulation, the effect of the unevenness of the secondary air on the reductive atmosphere near the water walls, the burnout rate at the furnace outlet as well as the flue gas temperature deviation and the slag volume is studied. Then, the bottom secondary air is optimized. The results indicate that after increasing the degree of the uniformity of the secondary air volume, the CO volume fraction declines from 4% to 3% at most of the rear wall. The burnout rate and the furnace outlet flue gas temperature deviation are improved obviously despite of slight increase of the NO_x volume fraction at the furnace outlet. The slag volume is reduced substantially and the high-temperature corrosion is also expected to be improved with the increase of the bottom secondary air volume.

An Accurate Investment Method of Power Grid Based on Full Life Cycle Input-Output Benefit

ZHANG Quan, DAI Xianzhong, HAN Xinyang, JIN Xiaoling, ZHANG Wen, CHEN Dan

2018, 51(10):  171-177.  DOI: 10.11930/j.issn.1004-9649.201708043

Asbtract ( )   PDF (2212KB) ( )  

References | Related Articles | Metrics

Power grid construction investment continues to grow and needs accurate investment method in power grid planning to improve economic efficiency. In this paper, a new method of the accurate investment of power grid planning (AIMPGP) based on full life cycle input-output benefits is proposed. First, considering the variety of power grid planning investment application scenarios, different scenarios are compared and selected based on input-output benefits, putting forward a comprehensive benefit evaluation index system and an evaluation method of power grid planning in different application scenarios. Secondly, six kinds of typical power grid planning investment scenario are chosen, and two feasible projects are refined for each scenario. Then, the optimal scheme set is divided into rigid demand and elasticity demand. Specifically, when the plan of investment funds is lower than the total investment demand, the rigid demand-type grid investment plan should be satisfied, and the flexible demand-type projects are arranged from high to low according to the investment efficiency level, until the investment plan of the grid project meets all the requirements. Finally, a provincial power grid is analyzed based on the proposed methods to demonstrate its feasibility and practical value.

A Comprehensive Evaluation Model for Power System with Large-Scale New Energy Considering Regional Differences

WANG Xiaochen, JIN Yanming, ZHANG Jinfang, WANG Xiaochen, YANG Bing

2018, 51(10):  178-184.  DOI: 10.11930/j.issn.1004-9649.201708069

Asbtract ( )   PDF (2274KB) ( )  

References | Related Articles | Metrics

The access of large-scale new energy will become a new feature of power systems in the future. At present, the evaluation on the power systems with large-scale new energy (PSLNE) are relatively simple, and can not reflect the differences between regions. The paper firstly analyzes the basic problems of power systems in the future, and then proposes a comprehensive evaluation model considering regional differences. A comprehensive weighting method, which is based on the subjective and objective weighting method, is used to evaluate the reliability, economy, environmental protection and efficiency of power systems. The concept of regional coefficient is introduced and the evaluating indices are differentiated to reflect the regional characteristics. Finally, three representative regions are selected for case study. The evaluation results show that the reliability and environmental protection of electrical power systems shall be given more attentions for the economically developed and densely populated areas, while the economy requirements may be relaxed appropriately for the areas where the power investment is sensitive.