Power Equipment

Archive

  • Select all
    |
    Research & Analysis
  • Research & Analysis
    Hydrodynamic Calculation and Safety Evaluation for the Water Wall in a Supercritical Boiler Under 30% BMCR
    Ni Xiaobin, Zhou Keyi, Xu Qinglan
    2021, 35(3): 149-156. https://doi.org/10.19806/j.cnki.fdsb.2021.03.001
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Taking the 650 MW supercritical boiler in a power plant as an example, to guarantee safety operation of the boiler during deep peak regulation process, a calculation model for flow and pressure of the water wall was established by equivalent loop method, while a heat load model was set up for a single tube in the spirally wound tubes, based on which, hydrodynamic characteristics of the water wall were calculated under ultra-low load conditions, and subsequently the outer wall temperature distribution at outlet of the spirally wound tubes and the mass velocity distribution of tubes in the upper and lower furnace were obtained. Based on the verified model, calculations and analyses were conducted on hydrodynamic safety of the water wall under 30% boiler maximum continuous rating (BMCR). Results show that the curve of pressure drop and mass flow in the spirally wound tubes of the supercritical boiler exhibits a one valued feature under 30% BMCR, and the pulsation of the tubes lies in a stable region with a large margin.
  • Research & Analysis
    Influence of the Key Adjustable Parameters on Energy Consumption of Cascade Heating System
    Li Yang, Huang Zhikun, Li Zhihua, Cen Lingshan, Luo Ruicheng, Su Zhigang, Wang Enzhen
    2021, 35(3): 157-161. https://doi.org/10.19806/j.cnki.fdsb.2021.03.002
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The method for energy consumption of cascade heating system was summarized. In the cascade heating system, the back pressure of the high back pressure exhaust steam is increased by utilizing the middle exhaust steam through the steam ejector to further heats the circulating water of the heat network, thus increasing the utilization of the high back pressure exhaust steam.The influence of the key adjustable factors on the system energy consumption index of the system was analyzed through experiments. Results show that the coal consumption can be reduced by increasing the amount of circulation water and decreasing the return water temperature of the heating system. The coal consumption reaches the minimum when the pressure boost ratio of steam ejector is controlled near the design point.There is no benefit for coal consumption by increasing the back pressure and steam pressure of the unit, and it just need to meet the working requirements of the steam injector.
    • New Energy
  • New Energy
    Effects of Cracks on Thermal Performance of a Round Bar Concrete for Solar Thermal Storage
    Zhu Huijun, Kuang Rao, Liu Guangpeng
    2021, 35(3): 162-166,171. https://doi.org/10.19806/j.cnki.fdsb.2021.03.003
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Effects of the following crack parameters on the thermal performance of a round bar concrete for solar thermal storage were researched through numerical simulation and theory analysis, such as the shape, center angle, width and position, while the changes of temperature differences of cracks during discharging heat process were given. Quantitative analyses were conducted on the relationship of thermal stress and each parameter by function fitting, so as to obtain the safety operation range of crack parameters. Results show that both of the temperature differences of arc- and chord-shaped cracks increase rapidly at first and then decrease gradually during discharging heat progress, and the temperature difference has a positive relationship with the center angle, width and position of cracks in generally. The obtained safety operation range of crack parameters can serve as a reference for the prevention of the damage of the solar thermal storage concrete.
    • Environmental Technology
  • Environmental Technology
    Application of Synergistic Removal Technology for Flue Gas Pollutants in a 660 MW Coal-fired Unit
    Jiang Zhihao, Du Yuhang, Qiu Jiajun, Liu Xiangmin
    2021, 35(3): 167-171. https://doi.org/10.19806/j.cnki.fdsb.2021.03.004
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Taking the existing flue gas purification process of a 660 MW coal-fired unit as an example, an analysis was conducted on the flue gas pollutant synergistic removal technology, and the flue gas purification system of the unit was retrofitted with the optimized technology. Results show that after adopting the flue gas pollutant synergistic removal technology, the emissions of flue gas dust, nitrogen oxide, sulfur dioxide and mercury all can meet the requirements of ultra-clean emission standards, while all the removal efficiencies of above flue gas pollutants are improved. This may serve as a reference for similar coal-fired units with ultra-clean emission retrofits.
  • Environmental Technology
    Optimization Analysis and Evaluation of Ammonia Injection for 300 MW Unit
    Gao Peng, Meng Qiang, Wang Chengliang, Wang Yujing, Lü Weizhi, Li Jianning
    2021, 35(3): 172-176. https://doi.org/10.19806/j.cnki.fdsb.2021.03.005
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Due to the change of coal quality and load fluctuation for a 300 MW unit, the NOx concentration deviation at the outlet of SCR denitration system is large. To ensure the NOx emission does not exceed standard, excessive ammonia injection inevitably aggravates the of ammonium bisulfate generation in the downstream air preheater. The ammonia injection optimization adjustment test was carried out for the SCR denitration system of the unit.Through multiple optimization and adjustment, the relative standard deviation of NOx concentration at the outlet section of SCR denitration reactor on the A side was reduced from 51.7% to 8.4% under the test condition, and the relative standard deviation of NOx concentration at the outlet section of SCR denitration reactor on the B side was reduced from 28.0% to 9.8% under the test conditiont, and the average ammonia escape concentration at the A and B sides was reduced from 2.10×10-6 and 3.10×10-6 before adjustment to 0.30×10-6 and 1.83×10-6, showing the optimization effect of ammonia injection was good.
    • Material Technology
  • Material Technology
    Precautions for Corrosion and Leakage of Super Duplex Stainless Steel Ball Valve
    Lu Yandong, Tian Hongzhi
    2021, 35(3): 177-184. https://doi.org/10.19806/j.cnki.fdsb.2021.03.006
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In terms of material selection, structural design, physical and chemical inspection, the causes of leakage failure of a super duplex stainless steel ball valve were analyzed, and the corresponding improvement processes were proposed to avoid the leakage failure of the ball valve.
  • Material Technology
    Failure Analysis of the Bursting Pipe on TP347H Type Austenitic Stainless Steel Made Platen Reheater
    Sun Xingxin
    2021, 35(3): 185-189. https://doi.org/10.19806/j.cnki.fdsb.2021.03.007
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The causes of TP347H tube burst in aplaten reheater of circulating fluidized bed boiler were studied based on the macroscopic analysis, chemical composition analysis, mechanical property analysis, metallographic structure observation, X-ray diffraction analysis, scanning electron microscope analysis and energy dispersive spectrum analysis. Results show that the main cause of TP347H tube burst is due to the long-term overheating. After long-term operation of the reheater, severe high-temperature creep phenomenon occurs in the local part of TP347H tube, the wall thickness is reduced, the thickness of oxide layer on the inner part exceeds the standard, a large number of creep holes in the metallographic structure, and the mechanical properties of the material decrease. At the same time, Nb (C, N) precipitated phase exists in the tissue with large size and is randomly distributed in the grain as inclusions, which further degrades the material performance.
  • Material Technology
    Reasons and Improvement Measures for Air Leakage of Tubular Air Preheater
    Li Xuedong
    2021, 35(3): 190-193. https://doi.org/10.19806/j.cnki.fdsb.2021.03.008
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Broken pipe samples of tubular air preheater from an overseas power plant were tested by chemical composition analysis, metallography analysis and scanning electron microscope (SEM)/energy dispersive spectroscopy (EDS) analysis to identify the reasons for air leakage. The air leakage is caused by low-temperature corrosion and can be inhibited by corrosion-resistant materials and bypass air ducts.
    • Automatic Control
  • Automatic Control
    Research on Dynamic Characteristics of Medium Speed Mill Based on DSLPSO
    Chen Lizhi, Dong Yunshan, Si Fengqi
    2021, 35(3): 194-200. https://doi.org/10.19806/j.cnki.fdsb.2021.03.009
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Taking a MPS-type medium speed mill in a thermal power plant as the research object, a gray box model was established for the medium speed mill with dynamic characteristics, and the dynamic self-learning particle swarm optimization (DSLPSO) algorithm was applied to the efficient identification of unknown parameters of the model, after which, the model was verified. Results show that the output data from the established model can better follow the actual output data of the mill, and through adopting the model, the outlet parameters of the mill can be predicted and the online monitoring can be realized for the water content of the pulverized coal. By controlling the flow rate and temperature of the inlet primary air, the water content of the pulverized coal and the outlet temperature of the mill can be effectively adjusted.
  • Automatic Control
    Research on Modeling of a Fully Loaded Ultra-supercritical Boiler-Turbine Coordination System
    Gao Zheng, Lü Jianhong, Qu Xiaofan, Ge Hao
    2021, 35(3): 201-206. https://doi.org/10.19806/j.cnki.fdsb.2021.03.010
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A study was conducted on the modeling of an ultra-supercritical boiler-turbine coordination system under full load condition, following which, the structure of the model was determined by analyzing the characteristics of the ultra-supercritical unit respectively in dry and wet state. The parameters of the model were then optimized by using the teaching-learning-based optimization (TLBO) algorithm. Finally, the model was tested with actual data to prove its validity.
    • Auxiliary Equipment Technology
  • Auxiliary Equipment Technology
    Development Status of Auxiliary System for Domestic Heavy-duty Gas Turbines
    Fan Xuefei, Wang Siyuan, Liu Chuanliang, Zhu Zhijie, Xu Qian
    2021, 35(3): 207-212. https://doi.org/10.19806/j.cnki.fdsb.2021.03.011
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    For the auxiliary system of domestic heavy duty gas turbines, an introduction was presented to the development situation and typical configuration of the auxiliary system, and analyses were conducted on the design technology, the industrial chain and the existing problem, etc. After which, the development gap between domestic and foreign industry was summarized, and corresponding countermeasures and suggestions were proposed.
    • Operation & Retrofit
  • Operation & Retrofit
    Application of Temperature Monitoring System for a Steel Indirect Air-cooling Tower Integrated with Chimney in a Thermal Power Plant
    Peng Lei, Yang Fuxin, Wang Xiaoliang, Yu Zhe, Han Biao, Wang Xingtao
    2021, 35(3): 213-217. https://doi.org/10.19806/j.cnki.fdsb.2021.03.012
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Taking a steel indirect air-cooling tower integrated with chimney in a thermal power plant as the research object, combined with the grating array sensing technology and the distributed control system, a temperature monitoring system was established to monitor the temperature of the air-cooling tower. Results show that the surface temperature of cooling triangle is within 10-50 ℃, and the system can operate safely; while the temperature distributes unevenly at the same time, and the maximum temperature difference is more than 10 K. The temperature monitoring system presents a good effect during trial operation, which can realize the intelligent control.
  • Operation & Retrofit
    Discussion on Co-firing with High Sodium Coal in Coal-fired Units
    Deng Shan, Lü Haitao
    2021, 35(3): 218-222. https://doi.org/10.19806/j.cnki.fdsb.2021.03.013
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To solve the problem of the serious contamination occurring in the rear heating surface of a 350 MW super critical boiler co-firing with high sodium coal, combined with analyses on the contamination characteristic of coal ash, the experience for co-firing at different unit loads was analyzed and summarized through co-firing experiments. Results show that the contamination of the high sodium coal is not only related to the content of sodium and potassium, but also closely related to the unit load, the co-firing ratio and the silica content. This may serve as a reference for the co-firing with the high sodium coal in similar units.
  • Operation & Retrofit
    Retrofit of Impulse Steam Turbine to Reaction Type in a Typical 300 MW Subcritical Unit
    Zeng Yapeng, Liu Huiming, Zhao Lüshun
    2021, 35(3): 223-226. https://doi.org/10.19806/j.cnki.fdsb.2021.03.014
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Based on comparisons on the main features of the impulse and reaction steam turbine, a scheme was proposed for retrofitting the impulse steam turbine to reaction type, and application effects were analyzed for adopting the scheme in a 300 MW subcritical unit. Results show that after the reaction type retrofit, the efficiency of each cylinder is improved significantly, and the heat rate declines dramatically.