Power Equipment

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  • 2016 Volume 30 Issue 5
    Published: 15 September 2016
      
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  • Research and Development of an Organic Rankine Cycle System Based on Waste Heat Utilization
    Zhang Fang, Xu Jianqun, Zhao Zhijun, Chen Feixiang
    2016, 30(5): 289-293.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Based on the principle of cascaded utilization of energy, an organic Rankine cycle (ORC) system was developed using high-temperature flue gas discharged from a micro gas turbine, of which the system performance was studied by setting up a mathematic model for the ORC system, taking R134a as the working fluid, and choosing screw expander as the engine. Results show that the power output and cycle efficiency of the ORC system are respectively 20.40 kW and 12.65%. The power system can not only recover low grade heat source, but also achieve zero emission of pollutants, having a wide application prospect.
  • Application of Segmented Low-temperature Economizer in the Flue Gas Heat Recovery System of a Boiler
    Wang Zhijun, Xiong Yuanquan, Su Yinhai, Song Jie
    2016, 30(5): 294-298,307.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To solve the problem that the quality of the extraction steam excluded by conventional one-part low-temperature economizer is limited by restrictions of the flue gas temperature, condensate water temperature and eventually exhaust temperature drop, a segmented low-temperature economizer flue gas waste heat recovery system was put forward to improve the quality of the extraction steam. Calculation and analysis results for both the conventional and segmented low-temperature economizer show that the thermal performance of segmented low-temperature economizer is superior to the conventional one, and the economic effect of segmented low-temperature economizer may be higher than the conventional one, through optimization of relevant system parameters.
  • Analysis on Thermal Deviation of W-flame Boiler Water Walls
    Wang Pu, Chen Duanyu, Yang Yong, Zhou Wentai
    2016, 30(5): 299-303.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The thermal deviation of water walls was calculated at different loads of a supercritical pressure W-flame boiler. Results show that large thermal deviation generates in the water wall at both high and low loads, and the thermal deviation is relatively small at the unit load of 450 MW; for the front and back wall, the thermal deviation coefficient is larger in the middle part while smaller at both sides in most cases; for the left and right wall, the thermal deviation coefficient distributes uniformly, or is just slightly higher in the area close to the front wall; for all the furnace walls, the average enthalpy rise of working medium declines with increasing unit load; the average heat absorption of front and back wall is higher than that of left and right wall.
  • Research on Performance of an Indirect Air-cooling System with Parallel Configuration
    Liu Li, Zhu Pengda, Tan Rui
    2016, 30(5): 304-307.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Performance tests were conducted on a new type air-cooling system with parallel configuration, during which the cooling effectiveness was proved to satisfy the design requirements under verification conditions. At high-temperature atmosphere in summer, the system can work stably at full load; whereas in winter, the freeze-proofing of indirect air-cooling system can be achieved by adjusting the operation mode, with the help of small cooling area of mechanical ventilation tower. The system overcomes the deficiencies of traditional air-cooling systems under high-temperature and high-cold conditions in Xinjiang.
  • Simulation on Heat Collection Performance of a Parabolic Trough Collector
    Cao Zheng, Zhang Zhibo, Chen Jiufa
    2016, 30(5): 308-313.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The effects of following factors on the heat collection efficiency of parabolic trough collector and on the maximal surface temperature rise of both the heat-absorbing tube and the glass sleeve were analyzed, such as the direct solar radiation intensity, the inlet fluid temperature and the inlet fluid velocity, etc. Results show that the heat collection efficiency of solar collector increases with rising direct solar radiation intensity, rising inlet fluid velocity and reducing inlet fluid temperature; the maximal surface temperature difference of heat-absorbing tube increases with rising direct solar radiation intensity and reducing inlet fluid velocity, which first increases and then reduces with the rise of inlet fluid temperature; the maximal surface temperature difference of glass sleeve increases with rising direct solar radiation intensity, rising inlet fluid temperature and reducing inlet fluid velocity.
  • Method of Quantitative Evaluation of Operating Experience Reports in Nuclear Power Plant
    Wu Jie, Hu Juntao, Zhuo Yucheng
    2016, 30(5): 314-318,341.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A comprehensive method on quantitative evaluation of operating experience (OPEX) reports in nuclear power plant is put forward from the aspect of industry reliability and risk importance. The screening criteria of risk importance is identified and then modified by referring to RG 1.174. With PSA models, simulated calculations are performed to verify the applicability of the evaluation method. Calculation results show that by using applicable screening criteria in the evaluation method, significant risk increase would not be introduced, and the equipment whose reliability is significantly below the average level in the industry would not be purchased, while no exorbitant reliability is to be required on the design reliability assurance program (D-RAP) equipment, proving the method to be applicable in quantitative evaluation of OPEX reports in nuclear power plant.
  • Simulation and Modeling on Dynamic Characteristics of a Wet Desulfurization Tower
    Wang Yongwen, Leng Wei
    2016, 30(5): 319-324.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A general mathematical model was set up to study the dynamic characteristics of a wet desulfurization tower respectively by wet ammonia method and wet limestone-gypsum method, based on analysis of the technological design and reaction process of the tower in different flue gas desulfurization systems, using lumped parameter modeling method and modular modeling method, with which the dynamic process of desulfurization tower in the whole operation process can be simulated, while the real-time dynamic operation data within control objects can be calculated, such as the temperature, pressure, pH value, SO2 mass concentration and the desulfurization efficiency, etc. Taking the desulfurization tower in a thermal power plant as an object of study, dynamic simulations were repeatedly conducted on the tower, and the simulation results conformed to the design requirements on dynamic characteristics of the tower, proving the model to be correct and universal.
  • Application of Single-tower Double-recycling Desulfurization Technology in 1 000 MW Coal-fired Units
    Wang Xiang, Yin Lingxiao, Qian Chenglong
    2016, 30(5): 325-328.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The application status of double-recycling absorption tower in 1 000 MW coal-fired units was analyzed, so as to study the effects of following setting parameters on the desulfurization efficiency, such as the liquid-gas ratio and the slurry pH value, etc. Results show that the desulfurization efficiency increases with rising liquid-gas ratio and slurry pH value, but the rising rate gradually slows down, and the pH value is generally controlled within 4.6~5.0 for absorption tower, and within 5.8~6.2 for AFT tower. The technology is also proved to have strong adaptability to coal category and load variation through experiments. For double-recycling absorption tower, the low pH value cooling loop ensures better gypsum quality, which can significantly enhance the oxidation rate and therefore reduce the power consumption of relevant oxidation fans.
  • Discussion on the Sampling Method for Nuclear Safety Class Ferrite Forgings
    Zhou Can
    2016, 30(5): 329-332.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Based on ASME NB-2223, an analysis was conducted on the reasons to apply different sampling methods for two forgings from the aspect of stress conditions and the factors impacting the forging properties, while some suggestions proposed for the application of these sampling methods.
  • Beam Fracture Analysis of Constant Hangers for High-temperature Reheater Outlet Piping in a 600 MW Supercritical Boiler
    Liu Shengming
    2016, 30(5): 333-337.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    An introduction is presented to the beam fracture failure of constant hangers for high-temperature reheater outlet piping in a 600 MW supercritical boiler, together with an analysis performed on both the fracture and the beam, such as macrostructure, microstructure, chemical composition and mechanical properties, etc., and subsequently corresponding countermeasures are proposed, which may serve as a reference for treatment on beam fracture of constant hangers in similar boilers.
  • Operation Optimization of Condensate Water Pump and Relevant Systems in a 300 MW Unit
    Zhang Shutong, Liu Qiliang, Liang Xiaoli, Jin Honghui
    2016, 30(5): 338-341.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To solve the problems of high power consumption, high water consumption, insufficient output at low load and unreasonable start up and shut down process of relevant systems existing in the condensate water pump of a 300 MW unit, optimization measures are proposed, which have helped to improve the operation effectiveness of the condensate water system, with good economic benefits obtained.
  • Optimization on Feed Water Control Strategy of a 660 MW Unit with Small Bypass System under FCB Condition
    Wang Feng, Zhong Shangwen
    2016, 30(5): 342-346.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Difficulties encountered in feed water control of a 660 MW unit with small bypass system under FCB conditions were analyzed, while the feasibility of using coal mill RB test to verify the feed water control strategy under FCB conditions was studied. Deep coal mill RB tests were conducted at high loads, and the test procedure was analyzed in detail, based on which relevant feed water control loops were optimized, and subsequently a control strategy was proposed by the automatic way of single steam pump water supply under FCB conditions. The deep coal mill RB test results conducted at medium and high loads prove the optimized control strategy to be effective, which may serve as a reference for FCB feed water control retrofit of similar units.
  • Application of Fieldbus Control Technology in 660 MW Units
    Wang Shipeng
    2016, 30(5): 347-349.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Application practice of Foundation Fieldbus (FF) and Profibus DP two configurations in power plant control networks is introduced, and problems occurring in the application process are analyzed, based on which corresponding countermeasures are proposed. Application results show that the control system can be perfectly applied by adding a conversion module PRMD 485-K20 between FF and Profibus DP, and by adopting an actuating mechanism supporting the Profibus DP protocol.
  • Start-up Mode and Turning Parameter Selection of a 1 000 MW Ultra-supercritical Double-reheat Steam Turbine
    Zhang Shiwei, Cui Kaifeng, Ye Luo, Zhang Guoyu, Xu Jianqun
    2016, 30(5): 350-352.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Compared with single-reheat steam turbine, the start-up process of 1 000 MW ultra-supercritical double-reheat steam turbine is faced with such difficulties as more complex system and higher start-up parameters, etc. Combining the typical start-up process of steam turbine in a 1 000 MW double-reheat unit during production and commissioning period, an introduction is presented to the optimization and adjustment on start-up mode and parameter control of similar steam turbines.
  • Discussion on Overhaul of 9E Gas Turbine Rotors
    Jiang Xiao
    2016, 30(5): 353-356.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To guarantee the safety operation of gas turbine in an overhaul life, a comprehensive inspection and analysis were implemented on the rotor status according to gas turbine working conditions and technical data provided by GE (OEM) in combination with onsite overhaul experiences. Results show that it is possible to effectively monitor and improve the operation conditions of gas turbine rotors and prevent them from serious accidents through implementing comprehensive inspection and analysis on gas turbine rotors as well as by taking proper treatment measures.
  • State Inspection and Adjustment of Steam & Water Piping Supports and Hangers in a Thermal Power Plant
    Kang Chaoyang, Li Liren
    2016, 30(5): 357-359.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Hot-state and cold-state inspection and adjustment are carried out on the supports and hangers for the main steam pipeline, high-temperature reheat steam pipeline, low-temperature reheat steam pipeline and high-pressure water supply pipeline of a thermal power plant. The stress and displacement of the four pipelines are checked with professional piping stress analysis software CAESAR Ⅱ, based on which safety operation of above thermal pipelines is guaranteed, while service life of the unit is extended.
  • Cause Analysis of Coal Feeder Measurement Errors and the Solution
    Chen Min, Zhou Jiajie, Liu Yijie, Lu Haiyan, Zou Zhijian, Jin Feng, Yan Jun, Zhang Guicheng
    2016, 30(5): 360-362.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    An introduction is presented to the basic principle of coal feeder weighing, together with an analysis on the causes leading to the measurement error in actual use, with corresponding countermeasures proposed to improve and maintain the accuracy of coal feeder measurement. The practice shows that these measures could solve the long-standing accuracy problems in coal feeder measurement, which is favorable for energy-saving and emission-reduction.