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    Research & Analysis
  • Research & Analysis
    Effect of CO2 Concentration on the Nucleation and Growth of Fine Coal-fired Particles by Heterogeneous Condensation of Water Vapor
    Xu Huanhuan, Zhang Jun, Zhang Yuanyuan
    2021, 35(2): 75-81. https://doi.org/10.19806/j.cnki.fdsb.2021.02.001
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To study the effects of CO2 concentration on the nucleation and growth of fine coal-fired particles by heterogeneous condensation of water vapor, mathematical models were established and an experimental platform was built, so as to theoretically and experimentally analyze the effects of CO2 concentration on the nucleation and growth of fine particles in the condensation chamber. Results show that with the increase of CO2 concentration, the thermal/mass diffusion coefficients of the mixed flue gas decrease, while the average supersaturation in the growth tube increases, with obvious growth of fine particles. The higher the wall temperature is, the larger the size of fine particles will be, with the increase of CO2 concentration.
  • Research & Analysis
    Research on Modeling Method of Gas Turbine Based on Nonlinear Autoregressive Neural Network
    Li Junkun, Zhang Xuyan, Yang Zhipeng
    2021, 35(2): 82-88. https://doi.org/10.19806/j.cnki.fdsb.2021.02.002
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    Aiming at the problem that the modeling of gas turbine mechanism is difficult due to the lack of design data, the nonlinear autoregressive neural network modeling method was studied, and the nonlinear autoregressive neural network simulation model of gas turbine was established by using the operation data of a gas turbine in service. The results show that the method can simulate the key parameters of gas turbine well, and verify the feasibility of establishing gas turbine simulation model with nonlinear autoregressive neural network.
  • Research & Analysis
    Comparsion and Study on Pyrolysis of Biomass with Different Water Ratios Based on Euler-Lagrangian Model
    Yu Boyang, Yin Lijie, Chang Qinghang
    2021, 35(2): 89-93,100. https://doi.org/10.19806/j.cnki.fdsb.2021.02.003
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    Based on Euler-Lagrangian model, the change of temperature distribution of biomass particles with different water ratios (mass fractions) was researched in a fixed bed, after which, with using OpenFOAM software, analyses were conducted on the change of average temperature of particles and solid phase mass fraction, and the temperature distribution of particles at different pyrolysis stages. Results show that the higher the water ratio of biomass is, the more unevenly the particle temperature distribution at middle pyrolysis stage would be. The water ratio has little effect on the temperature distribution of particles at early and late pyrolysis stage. While the effective heat transfer coefficient is improved with an increase of the water ratio during pyrolysis.
  • Research & Analysis
    Effects of Array Mufflers on Performance of a Natural Draft Counter-flow Wet Cooling Tower
    Zhao Chuanhui, Wei Hongqi, Wu Hao, Zhou Shuai
    2021, 35(2): 94-100. https://doi.org/10.19806/j.cnki.fdsb.2021.02.004
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To research the effects of array mufflers on the performance of a natural draft counter-flow wet cooling tower, parameters of resistance characteristics of the muffler were calculated by equivalent method. Numerical simulations were conducted on the inner flow field of the cooling tower through FLUENT software, so as to analyze the effects of array mufflers on the performance of the cooling tower and the outlet temperature of circulating water. Results show that the total pressure loss coefficient of the muffler is related to the length and ratio of the net flow area. With the arrangement of the array mufflers, the inner flow field changes obviously, the ventilation volume decreases and the outlet temperature of circulating water increases, which are all influenced by the surrounding angle of the mufflers arranged. When the surrounding angle is 180°, the outlet temperature of circulating water is raised by 0.18 K, and which is raised by 0.39 K when the surrounding angle is 360°.
    • Design & Manufacture
  • Design & Manufacture
    Design Optimization of 600 MW Subcritical W-flame Boiler
    Ran Shenming, Song Xiaohong, Mo Chunhong, Li Xusheng, Ma Xiaowei, An Renmin
    2021, 35(2): 101-105,116. https://doi.org/10.19806/j.cnki.fdsb.2021.02.005
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To solve the problems existing in the first generation 600 MW subcritical W-flame boiler, such as large amount of superheater spray water, over-temperature of platen superheater, high exhaust temperature, lower temperature of reheating steam under low load, high NOx emission, etc., the scheme was mainly optimized from furnace selection, heating surface adjustment, orifice design optimization, air classification in the combustion system and other aspects so as to develope the second generation 600 MW subcritical W-flame boiler. Results show that the main performance of the second generation 600 MW subcritical W-flame boiler is significantly improved compared with the first generation boiler.
  • Design & Manufacture
    Research and Application of Greedy Strategy in Tube Nesting Optimization for Power Plant Boilers
    Qu Mofeng, Xin Wei, Song Huaqiang
    2021, 35(2): 106-110. https://doi.org/10.19806/j.cnki.fdsb.2021.02.006
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Tube nesting in power plant boiler is generally of the variably-sized and one-dimensional kind. Considering the two situations between the length of the raw material and the target material, a solution method was proposed combining the greedy strategy with practical experience. It has been proved that the algorithm has the characteristics of high utilization rate of raw materials, fast operation speed, simple principle and easy implementation, which is suitable for practical applications of variably-sized and one-dimensional nesting.
    • Standard Research
  • Standard Research
    Accuracy Verification of DL/T 715 Revision for the Application Range of G102 (12Cr2MoWVTiB) Steel
    Zhang Fanzhi, Wang Xianming, Chen Jian, Huang Yijun, Liang Zhen
    2021, 35(2): 111-116. https://doi.org/10.19806/j.cnki.fdsb.2021.02.007
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The differences of application range of 12Cr2MoWVTiB steel were compared between the version 2000 and 2015 of the industrial standard DL/T 715 Selection Guide for Metallic Material of Fossil Power Plants. Combining with the application of 12Cr2MoWVTiB steel in the sub-critical boiler, the use of 12Cr2MoWVTiB steel through the aspect of industry standard, design parameters, on-site inspection, material detection and calculation were analyzed, and then the accuracy of standard revision was verified. For 12Cr2MoWVTiB steel tubes in service, the technicians of power plant need to estimate the service performance of steel timely through macro-inspection of steel tubes and sampling test in laboratory. This provides a basis of the subsequent safety operation and maintenance of this power unit, and also provides a reference for the operation and maintenance of boilers with similar steels.
    • Environmental Technology
  • Environmental Technology
    Optimization and Retrofit on Reducing NOx Emissions During Startup Process of Gas Turbine
    Ma Fanglei
    2021, 35(2): 117-121,130. https://doi.org/10.19806/j.cnki.fdsb.2021.02.008
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    During startup process of 9F gas turbine, NOx emissions over-standard commonly exists after ignition especially at low load stage. Reasons were analyzed and main steam system was technical reformed. Hot startup operation process of GE S109FA-SS gas turbine was optimized. Results show that NOx emissions decrease sharply during startup of gas turbine after optimization. Time of yellow smoke at low load stage is shortened by 30 min and brings benefits to the environmental indicators. Enterprise competitiveness in the market are promoted in further.
  • Environmental Technology
    Online Optimization of a WFGD System Based on GWO-BP Neural Network Algorithm
    Wang Tao, Ren Shaojun, Si Fengqi, Ma Lijun, Wang Liguang
    2021, 35(2): 122-130. https://doi.org/10.19806/j.cnki.fdsb.2021.02.009
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Based on operation conditions of slurry circulation pumps, a group of multi-modality models were established for online optimization of a wet flue gas desulfurization (WFGD) system by the grey wolf-optimized BP (GWO-BP) neural network algorithm proposed, and subsequently the effects of the following factors on the variation of outlet SO2 concentration were analyzed, such as the unit load and inlet SO2 concentration, etc. In addition, the performance of the group of models was verified through the switching test of a 660 MW unit. Results show that with the increase of unit load and inlet SO2 concentration, the change of outlet SO2 concentration increases after switching the pump, indicating high prediction accuracy and strong generalization ability of the group of models.
    • Operation & Retrofit
  • Operation & Retrofit
    Key Technology Research and Engineering Application of the Co-combustion of Sludge and Coal in a 300 MW Coal-fired Boiler
    Feng Bingquan, Li Debo, Sun Chaofan, Feng Yongxin, Liang Hanxian, Su Zhanqing, Zhang Weitian
    2021, 35(2): 131-136. https://doi.org/10.19806/j.cnki.fdsb.2021.02.010
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    For a 300 MW sludge and coal co-fired NO.1 boiler unit, theoretical study on the combustion characteristics and mixed test were carried out, the effects of different mixing ratio on combustion characteristics and pollutant emission of boiler were evaluated. The results show that when the mixing burning ratio is below 10%, co-combustion of sludge with 40% moisture content will lead to 7 K decrease of combustion temperature. The influence on the fuel characteristic and ash formation characteristic are negligible. There is no significant difference wear detected on the economizer heating surface. For the pollutant emissions, the release of NOx, SO2 and dust meet the emission requirements and the environmental protection standard. The heavy metals in the desulfurization gypsum, desulfurization wastewater, desulfurization slurry, fly ash and slag meet the emission requirements and the environmental protection standards.
  • Operation & Retrofit
    Treatment on Tripping Fault of a Single Steam Turbine-driven Feedwater Pump in a 350 MW Unit While RB Function not Running
    Xiao Jiangfei
    2021, 35(2): 137-140. https://doi.org/10.19806/j.cnki.fdsb.2021.02.011
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    While runback (RB) function was not running, a tripping fault of a single steam turbine-driven feedwater pump occurred in a 350 MW supercritical unit during trial operation. An illustration was presented for the tripping process, and following measures were adopted, such as stabilizing the feed water flow rate, reducing the boiler combustion rate, adjusting the main steam parameters, etc. Results show that with one tripped steam turbine-driven feedwater pump, in the condition that feed water is supplied by another steam turbine-driven feedwater pump with 50% boiler maximum continuous rating (BMCR) capacity and one motor-driven feedwater pump with 30% BMCR capacity, the unit load can be reduced to a range with steady and safety operation through taking appropriate measures.
  • Operation & Retrofit
    Cause Analysis and Solution for Slagging in a Power Plant with Co-fired High-sodium Coal
    Zhu Xuchu
    2021, 35(2): 141-144,148. https://doi.org/10.19806/j.cnki.fdsb.2021.02.012
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To solve the problem of serious contamination and slagging existing in boiler heating surfaces of a power plant, composition analyses were carried out for coal ash and slag sample, and the slagging index and the contamination index of coal ash were calculated, after which, comparisons were conducted on the slagging tendency and the contamination tendency of coal ash. Results show that the serious slagging is caused by co-firing a large amount of high-sodium coal, and the problem can be well controlled through adopting following corresponding solutions, such as adjusting the burned coal, enhancing the online slag (coke) cleaning, improving the gas temperature at furnace outlet, etc.
  • Operation & Retrofit
    Economy Analysis of a 330 MW Unit with Different Heating Modes
    Zheng Zhimin
    2021, 35(2): 145-148. https://doi.org/10.19806/j.cnki.fdsb.2021.02.013
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Taking a 330 MW heat and power cogeneration unit as the research object, in the heating condition of 250 MW and 100 t/h, a calculation and analysis was conducted on the economy of three heating modes with the equivalent heat drop method. Results show that the injection afflux heating has the maximum energy saving, and the hot reheat extraction steam heating has the minimum energy saving. The heating of exhaust steam from a back-pressure turbine has the energy saving between that of above two heating modes, and which has a better economy than the injection afflux heating in low coal price and high on-grid price.