Power Equipment

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  • 2016 Volume 30 Issue 2
    Published: 15 March 2016
      
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  • A Thermal Deviation Prediction Model for the High-temperature Heating Surface of Ultra Supercritical Boilers
    Yang Kaixuan, Ding Shifa, Tao Li, Chong Pei'an
    2016, 30(2): 71-76.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A mapping model of boiler operating mode and thermal deviation was established based on BP neural network, while a sensitivity analysis was made on input variables of the model to find the main factors that affect the thermal deviation of high-temperature heating surfaces under the condition of high boiler thermal deviation, so as to provide suggestions to lower the peak temperature of tube walls, slow down the formation rate of oxide scales, reduce the risk of explosive accidents, and therefore improve the safety of boiler operations.
  • Thermal Process Identification Based on Modified Ant Colony Algorithm
    Zhang Chengming, Zhang Yufei
    2016, 30(2): 77-80,84.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Based on the basic ant colony algorithm, the idea of artificial immune system was introduced to improve the initial distribution and adjustment mechanism of pheromones, and to optimize the selection probability function, so that the actual output of the system could be approached via ant colony identification method in a faster and more accurate way. Simulation results show that the method proposed has higher optimization efficiency and identification accuracy than the basic ant colony algorithm.
  • Experimental Study on Sliding Pressure Operation Optimization of a Domestic 300 MW Subcritical Unit
    Yin Ge, Li Guangwei
    2016, 30(2): 81-84.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Experimental studies were conducted to optimize the sliding pressure operation of a domestic 300 MW subcritical unit. Through comparative tests on performance of the unit between constant and sliding pressure operation respectively, an optimal sliding pressure operation curve was obtained. The new sliding pressure operation mode has helped to effectively reduce the heat rate of steam turbine, thus improving the operation economy of the unit under variable load conditions.
  • Combined Application of Bayesian Neural Network and Genetic Algorithm in Boiler Combustion Optimization
    Xu Rongtian
    2016, 30(2): 85-87.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To improve the boiler thermal efficiency and reduce the pollutant emission, a model of boiler combustion system was established using Bayesian neural network, to which multi-objective optimization was carried out by genetic algorithm. Simulation results with field test data of a boiler show that the method could well predict both the thermal efficiency of boiler and the mass concentration of nitrogen oxides, achieving multi-objective optimization purposes, which therefore may serve as a reference for boiler operation in an economic and environmental-friendly way.
  • Application of Inlet Air Cooling and Condensate Water Recovery Technology in East Africa
    Li Minfeng, Zhao Dongguang, Li Jigang, Wang Zhigang, Ye Fei, Jiang Hao
    2016, 30(2): 88-91,94.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The features of gas turbine inlet air cooling and condensate water recovery technology as well as their application range in East Africa were compared according to the factors of meteorological condition, capital investment and the source of water, etc., while the feasibility of the condensate water recovery technology applied in the gas turbine power plant was studied. Results show that reasonable inlet air cooling technology should be chosen in consideration of variety of factors like meteorological condition, total investment and water source in East Africa. The condensate water recovery technology is recommended when the inlet air cooling technology is adopted, so as to not only improve the gas turbine efficiency, but also achieve the purpose of energy conservation and environmental protection.
  • Discussion on Advantages and Disadvantages of Auto Tuning Function in the 9E Gas Turbine CPC Software Package
    Huang Xuecheng
    2016, 30(2): 92-94.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Through analysis on control principle of the 9E gas turbine CPC software package, the advantages and disadvantages of its auto tuning function were acknowledged, and subsequently optimization measures were adopted to deal with the disadvantages, so as to improve the operation stability of the 9E gas turbine under low-NOx combustion conditions.
  • Welding and Postweld Heat Treatment of AP1000 Steam Generators
    Yang Juwen, Li Shuangyan, Xu Chao, Zhang Maolong, Tang Jianwen
    2016, 30(2): 95-98,109.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To ensure the manufacturing quality of the third generation nuclear steam generator, many new technologies of welding and postweld heat treatment are developed by analyzing the structural features of the steam generator, including determination of welding filler materials and welding processes for the manufacturing process. Results show that the successful application of above new technologies in the manufacture of the third nuclear steam generator has laid a solid foundation for the subsequent AP1000 third generation and CAP1400 projects.
  • Cause Analysis of Failed Swing Wearing Test for Spherical Support Bearing in the AP1000 Steam Generator
    Dong Zezhong, Du mingjie, Gu Zhouzhou, Tian Hongzhi
    2016, 30(2): 99-102.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Based on detailed analysis of the causes leading to failed swing wearing test for spherical support bearing in the AP1000 steam generator from aspects of test tooling installation, bearing installation, swing frequency, assembly fit tolerance, material properties, and specific information of the bearing failure, etc., improvement measures were proposed for the test with focus on optimization of corresponding test tooling installation, bearing installation, assembly fit tolerance and so on.
  • Workshop Assembly Module of Condenser Tube Bundles for Large Nuclear Power Stations
    Ren Yifeng
    2016, 30(2): 103-105.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    For the workshop assembly module of condenser tube bundles in large nuclear power stations, focus points of the module were discussed from the technical point of view, while corresponding advantages and disadvantages were economically analyzed, based on which a suggestion was proposed to perform ID eddy current testing for all the titanium tubes.
  • Study on SCR Denitrification Technology of Power Plant Boilers in Low-load Operation Process
    Zhang Feiran, Yao Yushan, Xu Qi
    2016, 30(2): 106-109.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    During the practical application of SCR (selective catalytic reduction) technology in domestic coal-fired power plants, the economizer outlet flue gas temperature is always lower than the normal reaction temperature range of SCR catalyst in low-load operation process. To solve the problem, several methods for improving the inlet temperature of SCR reactor were studied, with focus on both the advantages and disadvantages of each method, which may serve as a reference for relevant engineering designs.
  • Discussion on Incineration Technology of Solid Wastes in CFB Boilers
    Cai Wengang
    2016, 30(2): 110-115.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Problems concerning incineration technology of solid wastes in circulating fluidized bed (CFB) boilers were discussed, while technical experiences about incineration of pure solid wastes without addition of coal were summarized to prevent ash bridge. Meanwhile, an analysis on design principles of the boiler furnace was carried out and factors to be considered during the design process were listed, based on an actual design example of boiler furnace, which may serve as a reference for persons of the same occupation.
  • Retrofit of a Denitrification System for Wide Load Operation
    Li Feng, Zhu Zaiji
    2016, 30(2): 116-119.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To solve the problem that the denitrification system of domestic power units above 300 MW can not be put into operation at low load after denitrification retrofit, a flue gas temperature coordinated scheme was proposed and implemented for wide load operation of the denitrification system. Structural features and control strategy of the scheme were introduced, while the effectiveness of the scheme in engineering applications was analyzed, which may serve as a reference for similar engineering projects.
  • Analysis on Operational Failure of Single 100% Capacity Feed-water Pump Turbine in an Ultra-supercritical Unit
    Shen Feng
    2016, 30(2): 120-123.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    For the abnormal condition occurring to the HP governing valve during load-up process of a single 100% capacity feed-water pump turbine in an ultra-supercritical power unit, comprehensive analysis was conducted on the influencing factors, such as the operation mode of condenser vacuum pump, circulating water flow rate, condenser back pressure and the efficiency of feed-water pump turbine, etc., based on the capacity and efficiency of the feed-water pump turbine. The fault was finally found to be caused by the leakage in the recirculation valve. The unit can run normally now after the valve is replaced.
  • Operation Practice of a SCAL Indirect Air Cooling System at Reduced Backpressures in Heating Mode and the Anti-freezing Measures
    Zhao Jiangang, Sun Jing, Shang Yuanjia, Dong Shujun
    2016, 30(2): 124-126.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    An analysis was conducted on the operation mode at reduced backpressures and the anti-freezing measures of a 350 MW SCAL indirect air cooling system in winter heating period, based on actual operation data and many years' experience. Results show that the SCAL indirect air cooling system can be operated at reduced backpressures in winter by taking effective anti-freezing measures, so as to remarkably improve the operation economy of the unit.
  • Development and Application of a Valve Status Diagnostic System for Steam Turbines
    Guo Bochun
    2016, 30(2): 127-130.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To overcome the frequent failures occurring in the valve of steam turbines, an automatic diagnostic system has been developed based on DEH internal hardware monitoring and communication technology, which is able to integrate following processes into the human-machine interaction interface, such as the status diagnosis, alarming, testing and maintenance of valve, by directly collecting the data of DEH and servo mechanism, programming, analyzing real-time and historical data, and so on. Application results show that the diagnosis of the proposed system is timely, accurate and reliable, convenient and intuitive, producing obvious economic effects.
  • Study on Vibration Behavior of a Domestic 600 MW Supercritical Steam Turbine in Variable Modes of Operation
    Hao Runtian
    2016, 30(2): 131-134,137.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Taking a domestic 600 MW supercritical air-cooling steam turbine as an object of study, vibration behavior of the steam turbine was analyzed in variable modes of operation, such as in run-up period, variable load operation and shutdown of sliding parameters, for which essential concerns were mentioned for control of the turbine vibration.
  • Flue Gas Heat Recovery Technology of a 1 000 MW Boiler
    Xu Rong, Ma Xuguang, Pan Jianqiang
    2016, 30(2): 135-137.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The flue gas heat recovery technology by adding a low-temperature economizer to the 1 000 MW thermal power boiler was introduced, including the way of low-temperature economizer type selection, so as to improve the overall operation efficiency of the unit, and to achieve simultaneous coal-saving, water-saving, CO2/SO2 emission reduction purposes, thus obtaining good environmental protection effects.
  • Analysis on Malfunction and Action-rejected Cases in Thermal Protection System of a Coal-fired Power Unit
    Hu Yiqun
    2016, 30(2): 138-140.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    An analysis was conducted on several malfunction and action-rejected cases in thermal protection system of a coal-fired power unit, to which preventative measures were proposed. Meanwhile, the experience of hardware and software application was summarized for the protection system. Application results show that above measures have helped to improve the reliability and stability of the protection system, thus securing stable operation of the unit.