Power Equipment

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  • 2018 Volume 32 Issue 4
    Published: 15 July 2018
      
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  • Technical Research on Boiler Flue Gas Waste Heat Recovery for Inlet Air Heating
    Lei Chengyong, Yin Jinliang, Zhang Yong, Li Bin, Liu Ruilin, Chen Baoxing, Chang Cheng, Wang Limin
    2018, 32(4): 231-234.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To heat the boiler inlet air under different working conditions, an open cycle waste heat recovery system was proposed, based on which the changes of coal consumption and boiler efficiency were analyzed. Results show that, by adopting this technology, the coal consumption could be reduced by 3 g/(kW·h), and the boiler efficiency could be increased by 0.1%, indicating good energy saving effect.
  • Simulation Study of a Heat Pump System with Plate Heat Exchanger as the Evaporator and Condenser
    Gao Jianqiang, Zhang Suli, Wu Xuyang, Zhang Chen, Wei Riguang
    2018, 32(4): 235-240.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Taking the heat pump system as an object of study, a simulation model was established for the complete solar-soil dual source heat pump system, of which the main operation parameters were simulated and analyzed for different operation periods, and the simulation results were subsequently compared with actual operation data. Results show that the model has high accuracy and strong stability, which is able to effectively simulate the dynamic variation of operation parameters, thus to realize on-line monitoring of relevant heat pump systems.
  • Study on Key Technologies for Sliding Pressure Operation Optimization of a Coal-fired Power Unit Based on Main Steam Flow
    Yang Wenzheng
    2018, 32(4): 241-245.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To solve the problem that the sliding pressure operation curve could not well answer to the change of heating extraction and back pressure in a coal-fired unit, an analysis was conducted on the sliding pressure operation optimization method taking the main steam flow as dispatch variables, while a calculation model was established for the main steam flow based on piecewise function, after which, the model was verified with experimental data. Results show that the values of main steam flow calculated by the model agree well with actual experimental data, which can satisfy the requirement of sliding pressure operation.
  • Exergetic Life Cycle Assessment of Jet Fuel from Biomass Gasification and Fischer-Tropsch Synthesis
    Yang Kai, Tao Wei, Xiao Jun
    2018, 32(4): 246-252.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    By means of exergetic life cycle assessment (ELCA), performance evaluations on resource consumptions and environmental impacts were carried out for jet fuel production via biomass gasification and Fischer-Tropsch synthesis, while a comprehensive performance evaluation and comparison were conducted on both the heat-and power-supply systems using by-product steam from the aspects of resource conversion efficiency, reproducibility and environmental performance. Results show that the resource conversion efficiency of the heat supply system is higher than the power generation system, and the power generation system is renewable whereas the heat supply system is non-renewable. Both the systems can get positive benefit from environment, and that from the power generation system is more significant. The reproducibility of the power generation system is inferior to the heat supply system, but its environment performance is better.
  • Operation Status Analysis of an SCR System for 350 MW Supercritical Units
    Meng Yongjie, Lü Weizhi, Zhang Tao, Zhou Wentai, He Xiang
    2018, 32(4): 253-256.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Performance tests were carried out on the SCR denitrification system of a 350 MW supercritical unit, while an analysis was conducted on the flow field uniformity, the ammonia injection uniformity and the concentration of escaped ammonia. Results show that following problems still exist in the single reactor, such as poor uniformity of flow field distribution and ammonia injection, and excessive concentration of escaped ammonia, etc. To solve these problems, both the flow field distribution and the ammonia injection should be optimized, and the ammonia consumption should be under control.
  • Simulation Analysis on the Influence of Flue Baffle and Elbow Structure on the SCR Flow Field
    Ji Mingbin, Cheng Zhihai, Qin Huan, Shi Guanghui, Zhao Yuwei
    2018, 32(4): 257-260.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To study the influence of structure and arrangement of an SCR system on the uniformity of ammonia injection and the efficiency of denitrification reaction, the denitration system of a 600 MW coal-fired unit was simulated using Fluent software, while the distributions of its velocity field and pressure field were analyzed. Results show that the use of right angle elbows and simple deflector plates would cause significant flow field deviations, leading to an increase in ammonia slip concentration during operation of the denitrification system, thus aggravating the dust accumulation in the system.
  • Nonlinear Mechanism Model and Dynamic Characteristic Analysis of a Steam Generator
    Wei Zhiwei, Wang Mingchun, Zhang Yufei, Wang Fuyu, Geng Jian
    2018, 32(4): 261-267.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A three-input two-output dynamic model was established for a steam generator, based on mechanism analysis of the generator using the method of partition combined with lumped parameters. The mechanism model was then transformed into a nonlinear dynamic one based on state space, with which numerical simulations were conducted, thus to provide a relatively complete way of model building and treatment. Results show that the model developed has a complete structure, with high accuracy, agreeing well with theoretical analysis, which is helpful for further study on water level control of steam generators.
  • Design of a Power System for the Control Rod Drive Mechanism of Nuclear Power Plants
    Shen Zhihua, Ling Zhibin
    2018, 32(4): 268-271.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To satisfy the requirement on power supply characteristics and performance of the power system for control rod drive mechanism (CRDM) of pressurized water reactor (PWR) nuclear power plants, a comprehensive analysis was conducted on the design features of domestic and overseas mainstream reactors, together with a discussion on the design of the excitation system, control system and relay protection system for related motor-generator set, after which an optimization was carried out on the design of the power system, which may serve as a reference for improvement and optimization of relevant CRDM power systems.
  • Analysis on Design Features of a New 1 000 MW Nuclear Moisture Separator Reheater
    Liu Kewei, Gao Jinlin, Hong Zengyuan
    2018, 32(4): 272-276.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To improve the independent design level of nuclear power moisture separation reheater (MSR), an analysis was conducted on structural features of various parts of the MSR in a new domestic 1 000 MW nuclear power unit, for which corresponding improvement measures were proposed. Results show that through independent design optimization, the steam pressure loss on shell side of the new 1 000 MW nuclear MSR could be controlled under 37 kPa, and the terminal temperature difference could be reduced to 8 K, resulting in improved economy and reliability of the unit.
  • Application Study of Stainless Steel Shear Studs in Special Modules of AP1000 Nuclear Power Stations
    Huang Zhongping, Yao Juntao, Zhuang Yuan
    2018, 32(4): 277-280.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To prevent welding defects from occurring in the process when carbon steel shear studs are welded to the S32101 duplex stainless steel plate, theoretical and case analysis were conducted, and subsequently corresponding countermeasures were proposed by using stainless steel shear studs instead of carbon steel shear studs, for which optimum welding procedures and parameters were determined after a lot of researches. Results show that by using stainless steel studs to replace carbon steel studs, the mechanical properties of weld joints can meet relevant design requirements.
  • Calculation and Analysis for Area Margin Test of Steam Generator in Nuclear Power Unit
    Shao Huifu, Wang Jianguo, Ling Xuehui, Han Bo
    2018, 32(4): 281-284.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To solve the problem of complex calculation for margin test of steam generator, a theoretical calculation model was set up based on analysis of the heat transfer mechanism, while an analysis model was established for experimental data of margin test, which were subsequently applied to evaluate the experimental data of a certain nuclear power plant. Results show that the calculated results agree well with actual experimental data, indicating high precision of the calculation model, which can meet the commissioning requirements of nuclear power units.
  • Application of the Merging of HT Reheater Tubes in Retrofit of a Heat & Power Cogeneration Boiler
    Liu Jianjiang, Chong Peian
    2018, 32(4): 285-289.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To meet the growing demand of large capacity heating under the premise of safety and stable operation of a heat & power cogeneration unit, a retrofit scheme was proposed and taken by merging the tubes of high-temperature(HT) reheater through checking calculation on relevant wall temperatures. Results show that both the demand of large capacity heating and the requirement of safety and stable operation can be guaranteed simultaneously after implementation of the retrofit with little work of transformation, which therefore may serve as a reference for retrofit of similar heat & power cogeneration units.
  • Study on Heating Capacity Improvement of a Subcritical Unit
    Zhou Renmi, Luo Haihua
    2018, 32(4): 290-293.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To meet the heating demand of a subcritical unit in large-flow operation mode, a multi-steam source cooperative heating method was proposed by extracting the steam from the reheater cold section, reheater hot section and the main steam line, through retrofit on relevant equipment and systems. Meanwhile, the influence of above 3 steam extraction ways on the unit's thermal economy was analyzed, based on which, an economical operation strategy was worked out, thus to achieve the objectives of thermoelectric load decoupling and multi-steam source cooperative heating of subcritical units in large-flow operation mode.
  • Research and Application of Comprehensive Auxiliary Steam System Operation Optimization for Combined Cycle Power Plants
    Wang Zhenyu
    2018, 32(4): 294-298.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To improve the operation reliability and economy of an auxiliary steam system in combined cycle power plant (CCPP), a study was conducted on the operation mode of the common header auxiliary steam system with starting-up boiler as steam source, while an analysis was carried out on its shortcomings. Taking the extraction of low-pressure steam or cold-reheat steam as a new auxiliary steam source, through equipment modification, operation mode optimization and control strategy improvement, the operation mode of auxiliary steam system was comprehensively optimized and then applied in an actual unit. Results show that the optimized operation mode is more flexible, with greatly improved operation reliability and remarkable energy saving effect of the auxiliary steam system.
  • Oxide Scale Control Schemes for the Superheater of a 600 MW Supercritical Boiler
    Wu Xueqing, Luo Shunxu
    2018, 32(4): 299-302.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To solve the problem of tube explosion occurring in supercritical boilers caused by exfoliation of oxide scales in the superheater, an analysis was conducted on the generation and exfoliation process of oxide scales in a 600 MW supercritical boiler. Based on economic and technical considerations, following three schemes were comprehensively compared, such as chemical cleaning, pipe upgrading and the combination of chemical cleaning and partial pipe upgrading, and subsequently corresponding suggestions were presented. Results show that, for the supercritical boiler unit having been running for 500 00 h, the scheme of chemical cleaning combined with partial pipe upgrading is the optimal one for the control of exfoliation of oxide scales in similar supercritical boiler units.
  • Systematic Retrofit of a Domestic Excitation Regulator for 9E Gas Turbines
    Peng Dan
    2018, 32(4): 303-305.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    An introduction is presented to the background and reconstruction plan for technological retrofit of an excitation regulator in a 9E gas turbine generator. By analyzing the external circuit wiring and control strategy of MICROREC K4.1 regulator, as well as the communication with Mark Ⅵ control system, and by studying corresponding localization retrofit schemes, the RCS-9410A digital excitation regulator was used instead of the original MICROREC K4.1 regulator, after which, various performance tests were conducted for the new excitation regulator. Results show that the domestic excitation regulator is well constructed, and its overall performance can satisfy the requirements of the power industry and national standards. The retrofit helps to improve the stability and economy of the unit.
  • Analysis on Stall Phenomenon of a Boiler Primary Air Fan
    Li Xingyong
    2018, 32(4): 306-308.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To solve the problem of frequent stalls existing in the primary air fan on B side of No.1 boiler in a power plant, according to the test standard DL/T469-2004 Fans Performance Testing in Situ for Power Boiler, performance tests were conducted on the primary fan to measure its pressure-flow curve and stall curve during shutdown period, while characteristic curve of the fan was fitted by measuring its operating parameters during normal operation period. The problem of frequent fan stalls was finally found to be caused by the small factor of fan safety that can not satisfy the stall margin requirements of fan.