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    Research & Analysis
  • Research & Analysis
    A Method for Robust Correction of Thermal Data Based on Interior Point Algorithm
    Xiong Zhiqiang, Zhu Xiaoliang, Ren Shaojun, Dong Honglin
    2020, 34(5): 297-305. https://doi.org/10.19806/j.cnki.fdsb.2020.05.001
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Based on the measured data of the regenerative system of steam turbine in a thermal power unit, a method was proposed based on interior point algorithm for robust correction of the thermal data to analyze the feed water system. Taking the mass balance equation and energy balance equation as the constraints, a mathematical model was established for the robust data correction and significant error detection, of which the performance was estimated. Results show that the algorithm has good true value approximation ability in the case of the measuring point with or without significant error, showing low fault propagation rate and high robust correction performance, simultaneously.
  • Research & Analysis
    Optimization and Analysis of Guide Vanes for Multistage High-pressure Centrifugal Pumps
    Zhou Wenxiang, Li Chunning, Wu Linhu
    2020, 34(5): 306-312. https://doi.org/10.19806/j.cnki.fdsb.2020.05.002
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Taking the multistage centrifugal pump as an object of study, to improve the internal flow pattern and optimize the design method for the guide vane, the problems, such as flow separation and vortex in the blade, were solved by changing the profile and thickening the latter part of the guide vane. Among three different blade models, the optimal one was determined using CFD analysis by comparing the velocity and pressure distribution inside the space vane through numerical calculation of the three-dimensional turbulent flow field. The internal flow field of the optimal space vane was analyzed at different flow rates, and in the case of 80% volume flow, there was certain impact at the inlet, while in the cases of 100% volume flow and 120% volume flow, no impact inflow and separation were found. Through the comparison of the flow rate-head curve and the flow rate-efficiency curve of the guide vane before and after optimization, the external performance of the centrifugal pump was found to be improved to some extent after optimization, and the guide vane could meet the design requirements in a wider range of flow conditions. At the same time, more obvious advantages could be obtained at higher flow rates.
  • Research & Analysis
    Numerical Study on NOx Emission of a Gas-staged Burner
    Ding Dongdong, Liu Daoyin, Liang Cai, Li Jiamin, Xie Shuchao, Liu Taixiao, Shao Mengmeng
    2020, 34(5): 313-318. https://doi.org/10.19806/j.cnki.fdsb.2020.05.003
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Taking the gas-staged burner as an object of study, the effects of fuel staging and flue gas recirculation on the NOx emission were studied by numerical simulation. Results show that when the volume proportion of primary gas decreases from 90% to 75%, the NOx emission at furnace outlet drops significantly from 184 mg/m3 to 127 mg/m3. The NOx emission could be reduced effectively by adopting the flue gas recirculation technology.
  • Research & Analysis
    Performance Study of a Cooling and Heating Energy Station with the Main Engines in Series and Parallel Arrangement
    Hong Jienan, Qu Lan
    2020, 34(5): 319-323,328. https://doi.org/10.19806/j.cnki.fdsb.2020.05.004
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    To make full use of low temperature waste heat resources, a comparative analysis was conducted on the energy-saving performance of a cooling and heating energy station that takes recycled heat from waste water of a power plant as the heat resources, with the main engines in series and parallel arrangement, respectively. Results show that in series arrangement mode, the COP of all the main engines rises in summer and winter, indicating higher energy-saving effectiveness than the parallel mode. It is recommended arranging the internal parts in series mode and the external parts in parallel mode.
  • Research & Analysis
    Cold Start-up Optimization for the Rotor in a 1 000 MW Ultra-supercritical Steam Turbine Unit
    Wu Lingxuan, Ji Dongmei
    2020, 34(5): 324-328. https://doi.org/10.19806/j.cnki.fdsb.2020.05.005
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A finite element analysis model was established for the high-pressure rotor of a 1 000 MW ultra-supercritical steam turbine using ANSYS software based on cold start-up data of the unit, so as to obtain the maximum stress curve during cold start-up process of the rotor. Different cold start-up optimization schemes were drawn up by changing the initial inlet steam temperature, for which, corresponding optimization effectiveness was analyzed. Results show that under the premise of constant start-up time, the service life of the high-pressure turbine rotor could be increased effectively by reducing the initial inlet steam temperature.
  • Research & Analysis
    Reliability Analysis of a 660 MW Coal-fired Boiler with the Three Main Fans in Single-row Configuration
    Li Shuangjiang
    2020, 34(5): 329-333. https://doi.org/10.19806/j.cnki.fdsb.2020.05.006
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Analyses were conducted on the reliability of a 660 MW supercritical coal-fired boiler with the three main fans (PA fan, FD fan and ID fan) respectively in single- and double-row configuration. Results show that the reliability of the three main fans has little influence on the unit reliability. The probability of unit reliability in the case of all the three main fans in single-row configuration is 0.186 4 percentage points lower than the case in double-row configuration. When all the three main fans are arranged in single-row configuration, the unit reliability would be very sensitive to the equipment reliability, and with the increase of unit peak-shaving capacity, the cost of failure would rise obviously in the single-row configuration.
    • Material Technology
  • Material Technology
    Comparative Study on Microstructures of Different Nozzle-Safe End Welding Joints
    Ru Xiangkun, Liu Meng, Zhang Maolong, Yang Chengdong, Tang Weibao
    2020, 34(5): 334-338,343. https://doi.org/10.19806/j.cnki.fdsb.2020.05.007
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A comparative study was conducted on the microstructures of two types of nozzle-safe end welding joints using scanning electron microscopy, energy dispersive analyzer and microhardness tester. Results show that in the nozzle-safe end welding joint with nickel-based alloy buttering, hardness peaks appear in the nickel-based weld metal about 1.8 mm and 3.5 mm away from the fusion line between low-alloy steel and weld metal; a hardness peak also appears in the stainless steel about 1.7 mm away from the fusion line between nickel-based weld metal and stainless steel. Whereas, in the nozzle-safe end welding joint without nickel-based alloy buttering, hardness peaks appear in the nickel-based weld metal about 5.0 mm away, and in the stainless steel about 1.6 mm and 3.4 mm from the fusion line between weld metal and stainless steel.
    • Nuclear Technology
  • Nuclear Technology
    Study on Seismic Qualification Methods for Reservoirs in Nuclear Power Plants
    Ding Duoliang, Zhu Youjun, Ge Lei
    2020, 34(5): 339-343. https://doi.org/10.19806/j.cnki.fdsb.2020.05.008
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To study the influence of liquid storage level on the safety of a liquid storage container when earthquake occurs in a nuclear power plant, the natural frequency and vibration response of the container were calculated by modal analysis and spectral analysis under the empty, half-water and full-water level condition, so as to find the harshest representative condition to perform seismic tests. Results show that under the same earthquake excitation, both the maximum displacement and the maximum stress under full-water level condition are far higher than that under half-water and empty level conditions, proving the seismic performance of the container with full level of water to be the poorest among the three conditions.
    • Environmental Technology
  • Environmental Technology
    Energy Saving Research and Application of a New WGGH System
    Huang Huijun, Xu Zhiqiang, Qian Chenglong
    2020, 34(5): 344-346,351. https://doi.org/10.19806/j.cnki.fdsb.2020.05.009
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    To achieve the goal of energy saving and "colored plume" elimination, a new water gas-gas heater (WGGH) system was proposed for energy saving and environmental protection, which uses the low-pressure condensate from steam turbine as the heating medium, and connects the original flue gas radiator with the desulfurized net flue gas heater in series to realize high efficient energy utilization. Results show that after retrofit, the new WGGH system can operate stably and met the design expectations. It can effectively reduce the coal consumption for power supply of the unit while ensuring the requirements of environmental protection.
  • Environmental Technology
    Research on Flue Gas Waste Heat Utilization System of Heating Units
    Chen Bingbing, Ning Guangfei, Li Guoyuan
    2020, 34(5): 347-351. https://doi.org/10.19806/j.cnki.fdsb.2020.05.010
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To maximize the energy utilization of flue gas waste heat, a retrofit scheme was proposed for the flue gas waste heat utilization system in a 2×350 MW supercritical coal-fired heating unit, i.e. using the flue gas to heat the water in heating network during heating period and to heat the condensate of main engine during non-heating period, respectively. In addition, calculation and analysis were conducted on the thermal economy of the retrofit scheme. Results show that the extraction steam reduced can work in the steam turbine, with 3 201.7 kW and 1 120.6 kW work increased during heating and non-heating period, resulting in an annual decrease of about 2 796 tons of standard coal, equivalent to an annual decrease of fuel cost by 1.96 million RMB for each unit, indicating good economic effects of the scheme.
    • Automatic Control
  • Automatic Control
    Temperature Control Strategy for (Super) High-pressure Cylinder Exhaust Steam of Double Reheat Steam Turbine Units
    Zhang Tianhai, Tang Keyi, Gao Aimin, Shu Jianjun, Liu Nana
    2020, 34(5): 352-357. https://doi.org/10.19806/j.cnki.fdsb.2020.05.011
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    To improve the operation stability of double reheat steam turbine units, an analysis was conducted on the factors affecting the temperature of (super) high-pressure cylinder exhaust steam in double reheat steam turbine units, while a discussion was carried out on the control method applied in the DEH system when abnormal temperature appears. Considering the bypass system capacity and DEH control method, the cutting off strategy was optimized for the steam turbine. Results show that through cooperative operation with the bypass control system, the unit trip probability due to abnormal temperature of (super) high-pressure cylinder exhaust steam could be reduced, while stable operation of the unit could be ensured.
  • Automatic Control
    Simulation Analysis on Dynamic Characteristics of a BFPT Control System
    Ma Xiaofei, Wang Junwei, Lu Guiming
    2020, 34(5): 358-361. https://doi.org/10.19806/j.cnki.fdsb.2020.05.012
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To solve the problem of unstable unit operation resulted from unstable exhaust pressure of the boiler feed pump turbine (BFPT), a mathematical model was established while a simulation research was conducted on the BFPT control system using Simulink software to analyze the effects of the exhaust pressure variation on the power output of the BFPT based on actual conditions of the thermal power plant. Results show that the design of the BFPT control system can meet the requirements of actual operation in windy days, when the exhaust pressure changes at 15 kPa/min, the variation of the power output is 2% of the rated value, and the regulating time is 41 s.
    • Operation & Retrofit
  • Operation & Retrofit
    Simulation Analysis of Steam Quality Fluctuation in a Boiler Drum and Retrofit of the Drum
    Wang Tianlong, Liao Tianyang, Li Ruiyu, Zhu Jianfeng, Ma Jinxing, Cai Chuangming, Song Changzhi, Cai Qiongke
    2020, 34(5): 362-365. https://doi.org/10.19806/j.cnki.fdsb.2020.05.013
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To solve the problem of steam quality fluctuation in a boiler drum, the internal structures of normal and abnormal drums were modeled, based on which, the flow characteristics in both the drums were analyzed using ANSYS software, and subsequently a retrofit scheme was proposed to improve the structure of the abnormal drum, while the corresponding internal flow characteristics were studied by simulation analysis. Results show that after retrofit of the internal drum structure, the steam quality returns to normal, indicating that the drum structure modified can satisfy relevant requirements.
  • Operation & Retrofit
    Comprehensive Retrofit on the Medium-speed Pulverizer of a 600 MW Unit
    Liu Jianhua, Li Jinjing
    2020, 34(5): 366-370. https://doi.org/10.19806/j.cnki.fdsb.2020.05.014
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To solve the problem that the inlet NOx mass concentration of the SCR denitration system (initial NOx emission concentration) is difficult to satisfy the requirement to guarantee the performance of a 600 MW unit, a retrofit was conducted on the interior structure of the medium-speed pulverizer based on field tests, while the curve of wind-coal ratio was optimized. Results show that the high initial NOx emission concentration is mainly caused by the large primary air flow in the pulverizing system. Through comprehensive retrofit on the medium-speed pulverizer, the primary air mass flow could be reduced by 10% within a reasonable range of wind speed, thus to reduce the initial NOx emission concentration by 20 mg/m3 without reducing the boiler operation economy.