Power Equipment

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  • 2018 Volume 32 Issue 6
    Published: 15 November 2018
      
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  • Numerical Simulation of the Flow Field in a Condenser Throat
    Zhang Yong, Jia Changsheng, Xu Yanjun
    2018, 32(6): 383-386.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A study was conducted on the flow field in the condenser throat of a 600 MW thermal power unit, together with an analysis on the factors influencing the flow field, such as the height of the low-pressure heater and the location of the steam outlet of boiler feed pump turbine (BFPT). Results show that when the low-pressure heater and BFPT's steam outlet are arranged at condenser throat, the non-uniformity of the outlet velocity distribution at that area would be increased. Besides, the uniformity of the outlet velocity distribution could be influenced by both the low-pressure heater arranged at different heights and the BFPT arranged at different locations.
  • Influence Analysis of Shutter Opening on the Performance of an Indirect Air-cooling Radiator Based on CFX
    Wang Hanyun
    2018, 32(6): 387-393.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Taking the SCAL indirect air-cooling radiator of a 600 MW unit as an object of study, numerical simulations were conducted with CFX software on the influence of shutter opening on the performance of radiator finned tubes in the air-cooling system according to the heat transfer and flow characteristics. Results show that with the rise of shutter opening, the resistance loss caused by heat transfer between air and finned tube increases, therefore in winter, when the shutter opening is very small, attentions should be paid to the adjustment of shuttle openings. Offset pressure distribution and temperature distribution occur in the flow section of air passing through finned tubes under the combined action of guide shutter and the angle between shutter and radiator.
  • Design and Application of the Fully Distributed Profibus Fieldbus Technology for Coal Conveying Control Systems
    Gao Fei
    2018, 32(6): 394-398.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Regarding the field and equipment condition of a coal conveying system, new concepts, segment design and layout plans were proposed for the coal conveying control system based on the fully distributed Profibus fieldbus technology, with focus on the development and implementation of the control program and diagnostic function, thus to achieve deep application of the Profibus fieldbus technology in coal conveying systems.
  • Research and Application of Coordinated Control Strategy for Combined Cycle Units Based on Combustion Mode Switching Mechanism
    Zhang Jian
    2018, 32(6): 399-402.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A new coordinated control strategy was proposed for the load distribution of combined cycle unit based on switching mechanism of combustion mode of 9E gas turbines, which helps to solve the problem of frequent switching of combustion mode and narrow range of load regulation that is easy to appear during load change process of the gas turbine in a combined cycle unit.
  • Economic Analysis of a Solar Aided Coal-fired Power System
    Song Pengfei, Zhou Lulu, Xu Zhicheng, Wang Qiyang, Li Liangguang
    2018, 32(6): 403-407.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Based on the design parameters of a 670 MW supercritical coal-fired power unit under 100% THA operating condition, an economic analysis was conducted on three schemes for the connection between solar collector and heat recovery system of the coal-fired power unit, while the factors influencing the levelized energy cost (LEC) of solar power generation were comparatively analyzed, such as the solar radiation intensity in Lhasa, Yinchuan and Beijing, as well as the outlet temperature of heat transfer oil in the solar collector, etc. Results show that the LEC increases firstly and then decreases with the rise of outlet temperature of heat transfer oil; besides, all the three schemes can improve the power output and thermal economy of the unit, among which, the scheme of solar collector in parallel connection with No.1 high pressure heater is the most economical and practicable one, due to its lowest LEC.
  • Study on Denitrification Performance of a Siderite Catalyst Prepared by the Pelleting Process
    Zhao Yunfei, Gui Keting, Huang Qiurun
    2018, 32(6): 408-413.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A new kind of catalyst was prepared by the process of pelleting with siderite powder, so as to study the effects of following factors on the denitrification activity, such as the calcining temperature, calcining time, calcining sequence and mass fraction of adhesives, etc., while the sulfur resistance and repeatability of the catalyst were researched. Results show that the siderite catalyst calcined at 450℃ has the highest denitration performance, with a denitration efficiency reaching 85% at the reaction temperature of 150℃; besides, the mechanical strength of the siderite catalyst can be improved by adding polyvinyl alcohol adhesives with a mass fraction of 9%, of which the denitration efficiency can be maintained in a high level. Sulfur resistance tests indicate that the existence of SO2 hardly influences the denitration efficiency of the catalyst at the reaction temperature of 270℃.
  • Effects of Economizer Surface Contamination on Economy of the SCR Denitrification Unit
    Fan Junhui, Ning Huabing, Wei Bin, Zhang Bo, Chen Peng
    2018, 32(6): 414-418.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Taking the 600 MW power unit as an object of study, thermodynamic calculations were conducted for the boiler at different cleanliness factors (CF) on economizer surface designed for 50% THA, 60% THA and 70% THA working conditions, so as to analyze the effects of economizer surface contamination on the economy of the SCR denitrification unit. Results show that the contamination on economizer surface would lead to the reduction of CF; the more the CF reduction is, the higher the flue gas temperature rise would be. When the CF drops to a certain degree, the SCR denitrification efficiency would increase, resulting in reduced denitrification cost at a certain degree, but the rise in exhaust gas temperature would lead to the increase in fuel cost of the unit.
  • Study on Qualification Test Method for 1E Class DC Electric Device of CAP Series Nuclear Power Plants
    Chen Zhi, Yang Xiao, Ding Duoliang
    2018, 32(6): 419-422,433.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The CAP series 1E class DC electric device is of the class 1 safety equipment in CAP nuclear power plant, an important issue to be solved during localization process is how to make its design meet the safety requirements through equipment qualification, thus to assure its safety function. By identifying the qualification requirements, a qualification program was developed for the CAP series 1E class DC electric device, with an introduction to the main test items, test sequence and test methods.
  • Numerical Analysis of an Access Door in the Circulating Cooling Unit of a Nuclear Power Plant
    Dai Meijun, Che Xiaolian, Luo Jianping, Chen Jie, Liu Guangping
    2018, 32(6): 423-428.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To ensure the sealing performance and strength of an access door installed on the bottom plate in a containment circulating cooling unit, a pre-compression nonlinear contact analysis was conducted on the hollow O-ring rubber by combining ProE with Ansys Workbench, while the deformation, mechanical strength and stiffness property of the access door were analyzed and verified through Ansys Workbench under the combined action of contact pressure, medium pressure and earthquake load, etc. Results show that both the seismic performance and sealing performance of the access door can meet the design requirements.
  • Fault Diagnosis of Thermal Power Equipment Based on Parameter Correlation Analysis
    Luo Chanchun
    2018, 32(6): 429-433.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the phenomenon that the correlation among various parameters of thermal power equipment changes during early stage of a failure, three diagnosis methods were proposed and compared based on parameter correlation analysis, including the Pearson, Spearman and partial correlation analysis, which were subsequently verified by taking the primary air fan as an object of fault diagnosis. Results show that the partial correlation between two variables would change significantly when an abnormal condition occurs in the operation of a fan.
  • Application of Double-side Dynamic Balance Method in a Two-stage Adjustable Vane Axial Flow Fan
    Zhao Weizheng, Chen Jie, Zhou Renmi, Gu Weifei, Hua Min
    2018, 32(6): 434-436,446.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In the process of solving the mass unbalance problem existing in a two-stage adjustable vane axial flow fan, the single-side dynamic balance method was found to be infeasible, since the method may lead to the decrease in vibration at one point, but to the increase at another point. Based on analysis of the double-side influence coefficients, a double-side dynamic balance method was proposed and applied, with the vibration at all measuring points satisfying the design requirement, which therefore may serve as a reference for settlement of similar problems.
  • Nozzle Burnout Analysis for a New Low NOx Swirl Burner with Annular Recirculation Zone
    Wang Junmin
    2018, 32(6): 437-441.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    After the burner in a power plant was retrofitted into a new type of low NOx swirl burner with annular recirculation zone, severe nozzle burnout and deformation failures were encountered by most of the burners. Based on theoretical analysis, the problem was found to be caused by too strong swirl intensity of the burner, too short distance between the annular recirculation zone and the nozzle, and too small opening of the secondary air damper, which was not enough to cool the secondary air nozzle. The problem was finally solved by taking following countermeasures, such as optimizing the air distribution at all levels for the burner, lowering the swirl intensity, pushing backward the firing position of pulverized coal flow, increasing the secondary air flow rate to improve the cooling effect on the burner nozzles, etc.
  • Discussion on Layout Pattern of the Main and Hot Reheat Steam Piping in a 660 MW Ultra-supercritical Unit
    Wang Xiao, Li Guangwei
    2018, 32(6): 442-446.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Taking the main and hot reheat steam piping of a 660 MW ultra-supercritical unit as the object of study, a comparison was made between the header-lateral layout and double-branch layout on the aspects of tube material consumption, cost of manufacture and steam flow resistance, etc. Results show that the double-branch layout is comprehensively better than the header-lateral one, which therefore may serve as a reference for engineering design of similar projects.
  • Technical Improvement of the Lubricating Oil Filtration System in a Gas Turbine Unit
    Liu Qianju, Liu Haibo, Yan Jing
    2018, 32(6): 447-449.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    An introduction is presented to the composition features and application status of the lubricating oil filtration system in a combined cycle gas turbine unit. By summarizing the existing operation and maintenance experience, an improvement scheme was proposed for the lubrication and filtration system, with focus on the determination of filter parameters, the assessment of various influencing factors, the functions and key design points of various components in the system, possible adverse effects that may be caused by the improvement, and necessary measures taken to deal with the adverse effects, etc. Operation results prove the improvement measures to be effective.
  • Circulating Water Waste Heat Recovery Based on Heat Pump Technology for Power Plants in South China
    Yuan Fang, Hong Jienan
    2018, 32(6): 450-453.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To recycle the waste heat in circulating water of power plants, three schemes were proposed for the purpose of central energy supply, such as the water source heat pump scheme using circulating water, the water source heat pump scheme using both circulating water and river water, and the absorption heat pump scheme using the steam of power plant and circulating water. By comparison of above three schemes, the one using circulating water is found to be most optimal, with highest adaptability to load, minimum total investment and lowest price of energy supply.
  • Study of Design Scheme for the Fuel Intelligent Management System in Thermal Power Plants
    Ying Botao, Gao Fei, Zang Jiannan
    2018, 32(6): 454-457.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To satisfy the cost-saving and profit-increasing requirement of thermal power plant, a study was conducted on the fuel intelligent management system. Taking the fuel coal as an object of study, and based on modern intelligent technology, a unified standardized management and control system was established to realize whole process intelligent control of fuel coal without intervention, thus enhancing the fine management on fuel coal and saving the production cost.