2018-10-01Analysisonfaultprobabilityofheatingsystembasedonanalytichierarchyprocess(AHP)

FUQiang1,ZHOUTian2,LIUYaowen1,LIUHaibo1,ZHAOJianing2,ZHOUZhigang2(1.Heilongjiang Longdian Electric Company Limited, Harbin 150000, China; 2.Harbin Institute of Technology, Harbin 150090, China)

Abstract:Heating is a project concerning people’s livelihood. Maintaining the health and stability of the heating system is of social significance. However, with the aging of the existing pipe network, heating faults and frequent accidents seriously affect the operation of the heating system, which adversely affects people’s quality of life. The causes of the faults in heating system are analyzed. According to the investigation results of the heating network, the evaluation system of the fault analysis on heating system is established by using analytic hierarchy process (AHP). Corresponding suggestions are given regarding different evaluation results.

Keywords:heating system; analytic hierarchy process (AHP); failure possibility; pipe network

2018-10-04Measuringmethodforwindturbinetowerslopebasedonrandomsampleconsensusalgorithm

LEIYang1,LANWei2,SHIChao1,ZHANGZhongquan2,LIUYongzhao3(1.Fair Friend Institute of Electromechanics, Hangzhou Vocational and Technical College，Hangzhou 310018，China; 2.Huadian Electric Power Research Institute Company Limited, Hangzhou 310030,China； 3.Zhejiang Engineering Geophysical Prospecting Academy, Hangzhou 310005, China)

Abstract:With the rapid development of wind power industry, there are frequent accidents of wind turbines since design defects, manufacturing problems and inadequate maintenance. Collapse of units is one of the typical accidents, which can be avoided by measuring the inclination of the tower. In order to improve the low detection accuracy caused by the detection outliers and noise that cannot be eliminated by the least squares method, it proposes a random sample consensus algorithm which has a better immunity to noises and outliers. According to the testing results from a wind farm in Guazhou, Gansu, it is proved that the algorithm can be applied well in tower barrel inclination detection.

Keywords:wind turbine unit；tower barrel；inclination; random sample consensus algorithm; least square method; accuracy

2018-10-07IncompletedifferentialPIDparametersofboilerdrumwaterleveloptimizedbygeneticalgorithm

YUANXuefeng1,MAJin1,QIANGShuo1,WANGJing1(North China Electric Power University,Baoding 071003, China)

Abstract:The control system of drum water level of industrial boiler is of multiple disturbance, non-linearity and great hysteresis. To overcome classic PID controller’s shortcomings which are the difficulties in adapting to the complex and variable boiler steam water control system, in guarantee the water level within given range, in reducing costs, and in guarantee the safe operation of the entire network. The optimization proportional, integral and differential control (PID control) strategy of genetic algorithm are studied and designed to control the boiler drum water level. The impacts of high frequency interference on the system arediminished by incomplete differential, which can effectively overcome the shortcomings of the classical PID control mode. Research shows that confirmed by MATLAB simulation software, the system can effectively overcome the influence of interference on water level, and improve the control as well as self-adaptability. It can maintain the water level within a given range, which is of great significance to the normal operation of the boiler.

Keywords:genetic algorithm; incomplete differential PID; boiler drum level; optimized parameters; MATLAB

2018-10-12DiscussiononwearingrepairtechnologyofrotorjournalofMS9001Egasturbinegenerator

XUJinlei,FUHongjun(Wenzhou Gas Turbine Power Generation Company Limited, Wenzhou 325013, China)

Abstract:After a long-time operation, there was rotor journal wearing on an MS9001E gas turbine generator in a power plant, which caused hydrogen leakage of the generator. After technical analysis and program comparison, laser cladding technology was used to repair the journal. It has achieved good results and provides experience for the journal wear repair of MS9001E gas turbine, the first-generation long-running turbine.

Keywords:MS9001E gas turbine; journal wearing; repair technology; laser cladding

2018-10-15Faultanalysisandcalculationofvoltagetransformerinter-turnshortcircuitatgeneratoroutlet

MAYunfei(Datang Central-China Electric Power Test Research Institute, Zhengzhou 450001, China)

Abstract:Taking a stator grounding fault protection caused by inter-turn short circuit of voltage transformer as an example, the inter-turn short circuit of voltage transformer primary winding is determined to be the cause of the protection action through comprehensive analysis of fault waveform and test data. The analysis and calculation on equivalent circuit of terminal voltage imbalance caused by the equivalent impedance reduction as the voltage transformer inter-turn circuit is shorted are made, which is helpful to understand the process of inter-turn short circuit. Finally, several possible situations and preventive measures leading to inter-turn short circuit are discussed, which can provide reference for the monitoring and safe operation of voltage transformer.

Keywords:voltage transformer; inter-turn short circuit; equivalent circuit; preventive measure

2018-10-19Reformingprogramthatswitchesregionalmicro-gridfromoff-gridtogrid-connected

BIANZaiping1,WANGXin1,WANGXiaoming2(1.Hainan Electric Power Design and Research Institute, Power Construction Corporation of China, Haikou 571100, China; 2.State Grid Anhui Electric Power Research Institute, Hefei 230000, China)

Abstract:Micro-grid power supply is taken by distribution syste-

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ms in remote areas of Hainan. Using the abundant renewable resources , and considering the cost of reconstruction, seamless switch of operation modefrom off-grid to grid-connectedis realized, which provide uninterrupted power to local residents reliably. The operation mode and control principle of micro-grid are introduced. The reforming program that switches regional micro-grid from off-grid to grid-connected is represented from system working principle and breakerreforming.

Keywords:regional micro-grid; distribution system reforming; grid-connect diverter switch

2018-10-22Applicationoflargetransformercomprehensivefaultdiagnosisbasedonfaultmodel

HANZhiyuan1,WANGGuangjian2,ZHANGXiaojing1,ZHOUYan1,FUKeJian2(1.Inner Mongolia Datang International Togtoh Power Generation Company Limited, Hohhot 010206, China; 2.Beijing Zhongtian Lanqing Environmental Technology Company Limited, Beijing 100010, China)

Abstract:The change of the dissolved characteristic gas and its content in the transformer oil reflects the type and the severity of transformer internal fault. The three-ratio method and the comprehensive analysis by fault model can basically determine the type and severity of the transformer fault. In the case of the C phase fault in the main transformer of#5 unit of a plant, the transformer is in need of overhaul. After the inspection with hanged hood, the discharge point is found inside the body. After treatment, the transformer is put into operation again and the measures to prevent the transformer fault are put forward. At present, the operation of the transformer is stable and oil chromatography is normal. The result shows that the diagnosis method is feasible and effective.

Keywords:fault model; transformer; comprehensive diagnosis; oil chromatography test; fault type; application

2018-10-27Failureanalysisof20Cr1Mo1VNbTiBhigh-temperaturebolt

WUHonghui1,WANGWei2(1.Guangdong Dianyan Boiler Pressure Vessel Inspection Center Company Limited, Guangzhou 510700, China; 2.Dongfeng TQM (Wuhan) Metal Forming Company Limited, Wuhan 430040, China)

Abstract:In a dismantling repairmen of a steam turbine of a power plant, a high-temperature bolt made of 20Cr1Mo1VNbTiB was found broken. The fracture causes were analyzed by fracture analysis, metallographic test, mechanical properties test at room temperature and chemical composition analysis. The results show that the stress concentration caused by the mechanical damage on the screw surface is the direct cause of the bolt breakage. At the same time, coarse crystal grain of bolt, the carbide precipitating under long-term high temperature/high-pressure operation, and reduce of impact toughness are the root causes of cleavage brittle fracture of the bolt.

Keywords:20Cr1Mo1VNbTiB; bolt; stress concentration; impact toughness; cleavage brittle fracture

2018-10-30Causesandtreatmentforlowoutputofwaterringpump

JINWei(Wangting Power Plant，Jiangsu Huadian Energy Company Limited,Suzhou 215155，China)

Abstract:The decrease of water ring pumpoutput will deteriorate the condenser vacuum, which directly affects the economy and safety of the unit operation. Ensuring the output stability of the water ring pump is of great significance for safety in production.It analyzes the reasons for the output decreaseof vacuum pump B in#14 unit and provides corresponding solution.Borescope detection and ZJ-821 disincrustant can greatly improved the heat transfer effect of the cooler in 14B vacuum pump, thereby restore the output of the water ring pump. The method for solving the anomaly of this device is typical and can be attributed to special solutions.

Keywords:water ring pump; borescope detection; disincrustant；cooler

2018-10-33Experimentalstudyandapplicationofcirculatingwatersimulationtestfullyreplenishedbyintermediatewater

YANGQitao(Huadian Tengzhou Xinyuan Thermal Power Company Limited, Tengzhou 277500, China)

Abstract:2×350 MW units of Huadian Tengzhou Xinyuan Thermal Power Company Limited carried out a simulation test on circulating water fully replenished by intermediate water. The dosages that met the water quality control standards required by safety and economic operation of the unit were determined. The field tests were made, whose results showed that the circulating water system had no scale or obvious corrosion. The safe and stable operation of the unit with high proportion of reused intermediate water was realized.

Keywords:circulating water; intermediate water reuse; simulation test; scale; corrosion

2018-10-37Transformationandthermaleconomyanalysison1000MWultrasupercriticalunitwithlow-temperaturefueleconomizer

MAJi(Huadian Laizhou Power Generation Company Limited, Yantai 261441, China)

Abstract:Taking the 1 000 MW ultra-supercritical boiler of#1 unit in Laizhou Power Generation Company whose annual average smoke temperature reaches 126 ℃, management integrating flue and gas emission regulation, as well as low-temperature economizer at outlet of air preheater are adopted to reduce the boiler exhaust temperature and absorb the boiler heat loss. It expounds the layout and water intake scheme of the low-temperature economizer of 1 000 MW ultra-supercritical unit, and analyzes the thermal economy of the low-temperature economizer by equivalent enthalpy drop method. The results demonstrate that the thermal efficiency of the unit is improved by the low-temperature economizer. It is of feasible and practical reference value in recovery of exhaust heat.

Keywords:low-temperature economizer；exhaust temperature; equivalent enthalpy drop method; thermal efficiency; waste heat recovery

2018-10-40Pumpcasingmaterialandselectionanalysisofseawatercoolingcirculatingpump

CHENShenwei(Zhejiang Zheneng Jiahua Power Generation Company Limited, Jiaxing 314201, China)

Abstract:The cracks on the pump casings of 2×1 000 MW units are analyzed. The causes of cracks on the pump casing are ana-

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lyzed from the chemical composition, mechanical properties and welding process. The corresponding preventive measures are proposed to ensure the safety and economy of the generator set.

Keywords:circulating water pump; pump casing; crack; seawater

2018-10-43ProblemsandimprovementmeasuresofM701DAgasturbineinletfiltrationsystem

WANGCaiwen(Jiangsu Huadian Qishuyan Power Generation Company Limited, Changzhou 213011, China)

Abstract:There are strict requirements on the pollutants concentration and particle size of intake air for gas turbines.The composition and function of the M701DA gas turbine compressor inlet filtration system are introduced.The problems in operation of the gas turbine compressor inlet filter are analyzed and discussed.Measures to extend the service life of the compressor inlet filter are proposed to improve the safety and economy of the gas turbine operation.

Keywords:gas turbine; air inlet filtration system; filter element; differential pressure; back-flush

2018-10-45AnalysisandtreatmentofcommunicationopticalfiberfaultinHongpingPowerStation

LIUKe1，NIESai2(Jiangxi Hongping Pumped Storage Power Company Limited, Jing’an 330603, China)

Abstract:With the development of smart grid, the requirements and standards for operation and maintenance of optical fiber network are increasing. It is imminent to improve the operation and maintenance level of optical fiber and reduce the its failure rate. It introduces the fault analysis and fault treatment of the communication optical fiber in Jiangxi Hongping Pumped Storage Power Station.The fault location was determined and the reason for the fault was analyzed according to the situation on site.Aiming at addressing the fault in optical fiber joint box, a corresponding reconstruction is put forward,which solves the high failure rate of communication optical fiber and provides reliable guarantee for its safe and stable operation.

Keywords:communication optical fiber; troubleshooting; joint box of optical fiber

2018-10-48DiscussiononplannedlayoutofpumpedstoragepowerstationsinHenanProvince

YANGYang(Huilong Branch of State Grid Xinyuan Company Limited, Nanyang 473000, China)

Abstract:In recent years, Henan Province’s power load, power supply structure and the pivotal position in the national power grid have undergone tremendous changes. In 2016, the maximum load has reached 52.08 million kW. The structure of power supply has been transformed from depending mainly on thermal power into basing on the coexistence of thermal power and external adjustment. Henan power grid begin to become the thermal power center for central China power grid and the hub for interconnecting Northwest, North China and Central China power grids, the three major regional power grids. The original pumped storage power stations cannot meet the need of power development. In order to ensure the safe and stable operation of the power grid, it is urgent to re-plan the layout of pumped storage power stations in Henan Province. It makes relevant discussion and recommendations.

Keywords:pumped storage power station;power load; power supply structure; peak regulation station; power grid safety

2018-10-50Discussionontheremotecontroldesignofthepulseelectromagneticvalveforthelargescalefixedlinejetbagfilter

PANYun,ZHANGBo(Guodian Science and Technology Research Institute Company Limited, Nanjing 210031, China)

Abstract:The blowing system of large scale fixed jet bag filter is equipped with large amount of pulse electromagnetic valves to control the ash blowing. A matrix control mode is introduced with its advantages and disadvantages. Compared with the conventional design mode, matrix control mode greatly reduces the remote DO points in control system and the corresponding investments, which can provide a new concept for the design of the remote control of the pulse electromagnetic valves for fixed line jet bag filter.

Keywords:fixed line jet; bag filter; pulse electromagnetic valve; matrix; remote control

2018-10-52Treatmentofslightlyexceedingdissolvedoxygenincondensatewaterofthermalpowerplant

HUHeng,XIAOChengming(Guodian Huangjinbu Generation Company Limited, Yugan 335101， China)

Abstract:The excess of dissolved oxygen in condensate water in thermal power plant will accelerate the corrosion and scaling of boiler pipeline and affect the heat transfer of boiler heating surfaces, which will bring serious safety hazards to the operation of units. Through vacuum test, change of condensation water flow within steady load and decreasing the water level of condenser hot well , it is found out that the reason for exceeding dissolved oxygen in condensate water is a leak point existing between the condensate pump inlet and the water level plane of condenser hot well. The exceeding dissolved oxygen in condensate water can be solved by governance.

Keywords:thermal power plant; condensation water; exceeding the standard of dissolved oxygen; leak point

2018-10-54Technicalanalysisandpreventionforunittrippingcausedbyelectromagneticeddycurrent

DUXilai(Inner Mongolia Datang International Tuoketuo Power Generation Company Limited, Hohhot 010206, China)

Abstract:Due to the unreasonable installation position, the metal cable tray is in severe electromagnetic field of the generator for long time. The electromagnetic eddy current heats the metal tray, and finally the insulation performance of the secondary cable in the metal trough box will be reduced, which leads to relay protection malfunction and unit tripping event. Conduct technical analysis on such accidents, and carry out self-checking and rectification from the equipment design, material selection, installation, commissioning and operation. Heating fault caused by eddy currentsshould be handled properly as early as possible to avoid such faults and ensure the reliability of power supply.

Keywords:electromagnetic eddy current; cable tray; secondary cable; relay protection; insulation

2018-10-56Progressindecarburizationtechnologyforcoal-firedpowerplantflyash

DENGQingde,JIHaihong,HUXin,BOYang(Huadian Electric Power Research Institute Company Limited, Hangzhou 310030, China)

Abstract:In order to select a removal process for unburned coal in coal ash from coal-fired power plants,fly ash flotation (wet me-

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thod) decarburization technology as well as fluidization, combustion and electric separation (dry method) decarburization technology are introduced respectively. The domestic and international research on the development and status quo of flotation decarbonization process and pharmaceutical system are summarized.The research results of tribo-electrostatic separation device and electric separation process are obtained.The problems existed in the flotation decarburization and electric separation decarbonization and their applicability arepresented.

Keywords:fly ash; decarbonization; flotation technology; fluidization technology; combustion technology; electrostatic separationtechnology

2018-10-59Analysisandapplicationoffluegasevaporationtreatmenttechnologyfordesulfurizationwastewater

LIANPeng，WANGKailiang(China Huadian Engineering Company Limited，Beijing 100160， China)

Abstract:Desulfurization wastewater，as the very end wastewater in a coal-fired power plant，is of complex quality and treatmentdifficulty. As a traditional desulfurization wastewater treatment process, the‘triplet tank’technology cannot make water quality conform to the increasingly strict development situation of environmental protection in China. The emission of desulfurization wastewater has been a serious environmental problem of coal-fired power plants. The demand for the zero discharge of the desulfurization wastewater is becoming more and more urgent. Using flue gas to evaporate desulfurization wastewater is feasible according to theoretical calculation and the technical road is relatively simple. The advantages and disadvantages of different technology roads of desulfurization wastewater evaporating by flue gas are compared, which provides references for the realization of the desulfurization waste water zero discharge.

Keywords:desulfurization wastewater；evaporation tower；atomizing spray gun；rotary atomizer

2018-10-63Technicalpracticeofdenitrationsystemfor600MWcoal-firedunitbeforegrid-connection

LIHaihao,LIHuijun,GAOMinglang(Huaneng Tongchuan Zhaojin Power Plant, Tongchuan 727100, China)

Abstract:Before the technical reform on equipment in Huaneng Tongchuan Zhaojin Power Plant, in-depth analysis of the parameters at each stage before start-up process were carried out. By optimizing the operation, the flue gas temperature at inlet of denitration system before grid-connection increased from 265 ℃ to 298 ℃. The smoke temperature reached the minimum temperature required by continuous spraying ammonia of denitration catalyst. The denitration system was put into practice before the grid-connection. The main technical measures and parameters before and after the adjustment are introduced for reference in solving similar problems.

Keywords:coal-fired unit; grid-connection; denitration system; technical measures; operation optimization; temperature of spraying ammonia

2018-10-65ApplicationofcentrifugaldustremovalanddemistingtechnologywithcondensationwetfilminWFGDsystem

ZHANGHongbin1,ZHAOXiaokun2,CHENGZijian1,XIALiang1,GONGLei1(1.Demister(Shanghai) Environmental Technology Company Limited,Shanghai 200120, China; 2.Huadian Inner Mongolia Energy Company Limited,Baotou 014000, China)

Abstract:In order to fulfill the requirement of thermal power units’ ultra-low emission, the mass concentration of dust in flue gas should be lower than 5 mg/m3and the mass concentration of slurry should be lower than 20 mg/m3, which request a 70% removal rate on average among various exhausted flue gas particles whose diameters are smaller than 3.5 μm. However, the ordinary demist device and the wet electrostatic precipitator afterwards in the desulfurization system can barely remove the nano-scale particles in the flue gas. According to the principle of condensed phase transition which can cool the wet flue gas after desulfurization, a centrifugal dust removal and demisting technology with condensation wet film is recommended.The precipitated water vapor can ‘capture’the micron-sized particles which can form large droplets after re-condensing and be removed by the demister. This technology can effectively remove particulate matter (dust, slurry) smaller than 3.5 μm in flue gas, and at the same time take into account the liquid level balance of desulfurization tower, save water consumption in the system, and significantly improve units’ economic efficiency.

Keywords:thermal power station; WFGD; flue gas and dust; ultra-low emission; condensation phase transition; dust-removal and demisting; water saving

2018-10-69Quantitativeanalysisofminimuminvestmentinsolarthermalpowergeneration

FANJie1,DUFengli2,SUNJianchao1(1.China Huadian Engineering Company Limited, Beijing 100088, China; 2.China National Solar Thermal Alliance, Beijing 100190, China)

Abstract:Solar thermal power generation generates electricity in an environmental, pollution-free and renewable way. It is of adjustable power output, but is of a higher cost than wind power and solar photovoltaic power at present. Solar thermal power generation can be divided into solar concentrating, heat absorbing, changing heat and heat storage. Quantitative analysis on the minimum cost of the 4 procedures are carried out separately. It is found that the material price of solar field, efficiency of solar thermal power system and construction exert regular impacts on the stability of the power generation and so does the unit cost of power station. By improving the efficiency of solar thermal power generation system, controlling the construction fee according to local climate conditions, controlling the financing costs, material and the material price for solar field, the investment for the whole system can be reduced.

Keywords:solar energy; thermal power generation; solar tower field; heat absorption, heat exchange and heat storage; investment reduction

2018-10-73Causeanalysisandtreatmentofabnormaloxygencontentinthewatertankofboronandwatermakeupsystemofnuclearpowerplantreactor

CAOYusheng1,YAOQi1,CAIQingqiang2(1.CGN Yangjiang Nuclear Power Company Limited, Yangjiang 529941, China; 2.Guangzhou Development Distributed Energy Station Management Company Limited, Guangzhou 511458, China)

Abstract:Since the commercial operation of nuclear units of CGN Yangjiang Nuclear Power Company Limited, there have been 15 cases of excessive oxygen content in the storage tank REA001/002BA for demineralized and deoxygenized water. The water tank is mainly used for water makeup to the primary loop. If the oxygen content exceeds the standard, the makeup water of the primary loop of the nuclear power plant will be unqualified, which will seriously affect the safe operation of the unit. Considering the REA001/002BA water loop equipment, equipment in REA tank room, piping and valves of pump room, and REA sampling equipment, the excessive oxygen content is analyzed and the treatment measures are proposed.

Keywords:nuclear power plant; water tank of reactor boron and water makeup system; oxygen content; exceeding the standard