Archive

  • Select all
    |
    Boiler Technology
  • Boiler Technology
    Numerical Analysis on Influence of Extra Fin on Thermal Deformation of Membrane Water Wall Tubes in a CFB Boiler
    YANG Rui, CHEN Ye, LU Xiaofeng, YANG Mingjun, SHI Junlin, LI Tao
    2022, 42(6): 493-497. https://doi.org/10.19805/j.cnki.jcspe.2022.06.001
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Based on the experimental data of the first 600 MW supercritical circulating fluidized bed (CFB) boiler in the world, the calculation model of 4.6 m×2 m membrane water wall tubes was established by ANSYS software. Numerical simulation of the thermal deformation of water wall tubes under 100%BMCR (boiler maximum continuous evaporation) condition was carried out, and the influence of extra fin on the backfire side and their sizes on the thermal deformation of the tubes was analyzed. Results show that due to different heat load distribution in the furnace, with the increase of the furnace height, the thermal deformation of water wall tubes towards the fire side firstly increases and then decreases, reaching the maximum value (1.43 mm) at the furnace height of 39.5 m. Welding an extra fin on the backfire side of the water wall tube can effectively reduce the thermal deformation of water wall tubes. When the size of the extra fin is 6 mm×4 mm, the thermal deformation of the water wall tube towards the fire side is reduced to 0.57 mm.
    • Steam Turbine and Gas Turnine
  • Steam Turbine and Gas Turnine
    Research Progress and Prospect of Large Capacity Steam Turbine Technology in China
    SHI Jinyuan, LI Jun, LIU Xia, YANG Yu, SUN Qing, XIA Xinlei, QI Hao
    2022, 42(6): 498-506. https://doi.org/10.19805/j.cnki.jcspe.2022.06.002
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    From the perspective of large capacity steam turbine technology development,remarkable progresses from 2010 to 2019 and research prospect in China were reviewed.The background of large capacity steam turbine development was introduced,and new achievements on large capacity steam turbine technology research for thermal power and nuclear power in recent decade were summarized,including three technologies,such as the optimization of flow path and the performance at the wide range of load to improve efficiency; comprehensive design technology concerned with structural strength and lifetime,rotor dynamic and support,high temperature material and welding rotor to ensure safety; automatic turbine one-key start-up or shutdown control and thermal stress monitor to enhance the operation flexibility. Based on the development status,research prospect of domestic large capacity steam turbine was proposed in aspect 700℃ high temperature nickel alloy component,non-nickel alloy high temperature rotor,2 000~2 300 mm half-speed long blade for 2 000 MW nuclear power steam turbine,and intelligent technology of design,manufacture,operation and maintenance.Further target of large capacity steam turbine development is to promote the efficiency,guarantee reliability, safety and operation flexibility.
  • Steam Turbine and Gas Turnine
    Modeling and Simulation of a Gas Turbine Based on Series Form Intelligent Fusion Algorithm
    LI Wei, HE Xing, XU Ye, XUN Jinzhu, WANG Xu, BAO Zhe
    2022, 42(6): 507-513. https://doi.org/10.19805/j.cnki.jcspe.2022.06.003
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In order to improve the accuracy and practicability of entire dynamic simulation model of a gas turbine, based on the preestablished three types of single simulation models (i.e. mechanism, BP neural network and stepwise cluster analysis models), two types of intelligent fusion simulation models were innovatively formulated through combining mechanism model with BP neural network model and stepwise cluster analysis model, respectively. Fusion simulation models would effectively overcome the oversimplification and the difficulties in parameters identification related to mechanism model, as well as the high dependence on data quality and lack of extensive property associated with intelligent prediction models. The above models were applied to the simulation study of a gas turbine in a steel plant in Liaoning Province. Results show that the prediction effects of intelligent simulation model are better among all single models, in which stepwise cluster analysis model is superior to BP neural network model. Intelligent fusion model has a higher precision than the single models, and the model combining the mechanism with stepwise cluster analysis owns the better performance.
    • Monitoring and Measurement
  • Monitoring and Measurement
    Research on Fault Warning Method of Wind Turbine Gearbox Based on CAE and BiLSTM
    XIANG Ling, ZHU Haowei, DING Xian, TANG Haining, HU Aijun
    2022, 42(6): 514-521. https://doi.org/10.19805/j.cnki.jcspe.2022.06.004
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the problem of frequent failure and the difficulty of early fault monitoring of wind turbines, a method based on convolution autoencoder (CAE) and bi-directional long short-term memory (BiLSTM) was proposed to forecast the fault of wind turbine gearbox and realize the intelligent monitoring of wind turbines. Firstly, the data from supervisory control and data acquisition (SCADA) system were preprocessed, and the monitoring parameters that could represent the running state of wind turbine gearbox were selected as the output. The monitoring parameters highly related to the output were selected as the input parameters by correlation analysis. Then a deep learning network model was constructed based on the feature selection and nonlinearity of parameters. The predicted value and residual value of the output were statistically analyzed by using this model, and the adaptive threshold was set to detect the trend of the wind turbine abnormal state. CAE-BiLSTM model was used in a case analysis of a wind farm, and the prediction effects were compared between the model and other models. Results show that the proposed method can solve the redundancy problem of the input and structure, and improve the model accuracy. The gearbox early fault of wind turbine can be effectively detected by using the method.
  • Monitoring and Measurement
    Bearing Fault Analysis of Deep Learning Based on Improved CEEMDAN Algorithm and Fractal Fusion
    XIAO Junqing, JIN Jiangtao, YUE Minnan, LI Chun, XU Zifei, SUN Kang
    2022, 42(6): 522-529. https://doi.org/10.19805/j.cnki.jcspe.2022.06.005
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To solve the problems of false and redundant components in CEEMDAN algorithm for nonlinear vibration signal processing, an improved complete ensemble empirical mode decomposition with adaptive noise (ICEEMDAN) fusion convolutional neural network (CNN) method was proposed based on fractal theory. Taking the experimental data and simulation signals of bearing damage as analysis objects, CEEMDAN algorithm was used to decompose them and achieve noise reduction,and then the principal component analysis (PCA) was used to extract effective fault features.The fractal box dimension was used to screen the optimal reconstruction components and eliminate the irrelevant components, eventually CNN further excavated them to realize fault diagnosis recognition and classification. Finally,the proposed method was compared with several existing fusion deep learning methods and visualized by t-SNE to verify its reliability and practicability. Results show that the proposed method has strong robustness and generalization for experimental data, and the classification accuracy is improved by 0.54%-10.33% compared with the original method.
    • Auxiliary Equipment Technology
  • Auxiliary Equipment Technology
    A Bionic Approach for Axial Flow Fans to Reduce the Noise
    YANG Wenqi, SAI Qingyi, GUO Dange, HUANG Diangui, WANG Naian
    2022, 42(6): 530-536. https://doi.org/10.19805/j.cnki.jcspe.2022.06.006
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Numerical simulation of the blades with serrated trailing edge and wave leading edge was carried out to study noise reduction effects on axial flow fan. For the serrated trailing edge blade and wave leading edge serrated trailing edge blade with different tooth heights and tooth numbers, RANS and DES were used to calculate the flow field, and FW-H acoustic analogy equation was used to calculate the sound field. Results show that in the range of working conditions, the effect of noise reduction of the wave leading edge and serrated trailing edge blade is better than that of the serrated trailing edge blade, and these two kinds of blades have little effect on total pressure efficiency. For the serrated trailing edge blade, the total sound pressure level decreases with the increase of tooth height and tooth number, and the noise reduction effect is better when the tooth number is more. The total sound pressure level of the wave leading edge serrated trailing edge blade is lower than the original blade, therefore the noise reduction effect of wave leading edge serrated trailing edge combination applied to the axial flow fan blade is better.
    • Environmental Protection Technology and Equipment
  • Environmental Protection Technology and Equipment
    Experimental Study on Ammonia Injection Denitrification in High- temperature Primary Combustion Zone of a 330 MW Pulverized Coal-fired Utility Boiler
    BAI Hao, ZHANG Jian, ZHANG Zhongxiao, GUO Xinwei, WU Xiaojiang, ZHANG Qichao
    2022, 42(6): 537-543. https://doi.org/10.19805/j.cnki.jcspe.2022.06.007
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The effects of various factors on ammonia injection denitrification in high-temperature primary combustion zone were studied on a 330 MW corner-tangentially pulverized coal-fired boiler. Results show that NOx can be effectively removed by injecting urea solution into the high-temperature primary combustion zone, and the denitrification efficiency is affected by boiler load, air distribution mode and O2 volume fraction.When injecting ammonia into primary combustion zone on the basis of the conventional operation of the boiler, the optimum RNSR increases and the denitrification efficiency decreases with the increase of the boiler load. Compared with the reference air distribution mode, ammonia injection under the extreme air distribution mode can improve the denitrification efficiency and reduce the optimal RNSR. Reducing the O2 volume fraction at the boiler outlet can further increase the denitrification efficiency of ammonia injection in the primary combustion zone. The combination of ammonia injection in the primary combustion zone and high velocity over-fire air can effectively control the carbon content in fly ash and CO volume fraction, while the mass concentration of NOx is reduced.
  • Environmental Protection Technology and Equipment
    Experimental Validation of Calculation Method on Wet Flue Gas Plume Elimination of Coal-fired Units
    LI Guangying, ZHAO Qinxin, DENG Shifeng, LI Jianjun, ZHAO Ping, WANG Yungang, SHAO Huaishuang
    2022, 42(6): 544-551. https://doi.org/10.19805/j.cnki.jcspe.2022.06.008
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In order to eliminate the wet plume formed by the mixing of wet flue gas at the tail of the coal-fired power station and low-temperature air, and to solve the haze problem caused by the wet plume, based on the condensation-reheat route to eliminate plume, the research combining field experiment and tangent method calculation were adopted. The experimental platform was built after desulfurization tower of a 350 MW power station to verify the reliability of the tangent method. Besides, the critical temperature of wet plume elimination of different technical routes was also calculated by the tangent method.Results show that the relative error between the data obtained by experiments and tangent method can be controlled within ±10%. By comparing the critical temperature of wet plume elimination of different technical routes, the thermal parameters and applicable conditions are determined, which can guide the actual operation of plume elimination system in coal-fired units.
    • New Energy
  • New Energy
    Multi-model Self-adaptive Prediction of Superheated Steam Temperature at the Outlet of the DSG Solar Collector
    ZHU Qing, WANG Guangjun, CHEN Hong, WU Hui
    2022, 42(6): 552-558. https://doi.org/10.19805/j.cnki.jcspe.2022.06.009
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A multi-model self-adaptive prediction model of superheated steam temperature at the outlet of collector was established for the direct steam generation (DSG) trough solar thermal power generation system. The DSG collector was divided into several linearized subspaces according to solar radiation intensity. Based on the general distributed parameter model(GDPM) of the DSG collector and step response of superheated steam temperature, the nonparametric linear sub-model space of superheated steam temperature for the DSG collector was constructed, and a comprehensive scheduling strategy for the linear sub-model was established. Finally, a multi-model self-adaptive prediction model of superheated steam temperature for the DSG collector was obtained based on the idea of multi-model self-adaption, and the effectiveness of the model was verified by numerical simulation. Results show that the established model shows good adaptive ability, which provides necessary support for the predictive control of superheated steam temperature of the DSG collector.
  • New Energy
    Optimization of Key Structures for Transcritical CO2 Ejector
    NIU Qingyu, GUAN Xin, SONG Ziye, QIN Tao
    2022, 42(6): 559-567. https://doi.org/10.19805/j.cnki.jcspe.2022.06.010
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Two-dimensional numerical simulation was carried out for the ejector with CO2 as working medium, so as to analyze the following phenomena in the ejector, such as non-equilibrium phase transition, choking and shock wave. In addition, variations of velocity, static pressure and Mach number in the process of fluid flow in the ejector were deeply discussed. Furthermore, effects of nozzle diameter, the distance from nozzle outlet to mixing chamber and diameter of the mixing chamber on injection performance were studied. Results show that there exists an optimal value corresponding to the maximum jet coefficient for the three key structural parameters, respectively. Under the above optimal conditions, the internal shock intensity of the ejector is small, the choking phenomenon can be alleviated, and optimum ejector performance can be obtained.
    • System Engineering
  • System Engineering
    Study on Power Characteristics of Wind-Coal-Battery Coupling Integrated Power Station
    ZHANG Lei, GUO Yu, SHI Jiahao, SUN Enhui, ZHANG Qian, LI Yongyi
    2022, 42(6): 568-574. https://doi.org/10.19805/j.cnki.jcspe.2022.06.011
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A wind-coal-battery coupling integrated power station was constructed, and the optimal scheduling strategy of the proposed power station was planned under the assumption that the coal-fired unit can reach no inertia delay response and the energy storage battery can switch the storage/release state in seconds. Besides, the proposed power station was compared with regional independent power station from the following aspects, such as power volatility rate, power abandonment rate and power shortage rate, which was verified by Matlab software. Results show that compared with regional independent power station, power volatility rate of the proposed power station decreases from 1.306% to 0.178%, power abandonment rate decreases from 0.667% to 0.145%, and power shortage rate decreases from 0.643% to 0.010%, indicating that the proposed power station greatly improves its response ability to automatic generation control (AGC) load command.
  • System Engineering
    Comparison of Electrothermal Coupling Performance Based on Flat Plate PV/T System of Square-tube
    GAO Yanfei, HE Weifeng, LU Yu, HAN Dong
    2022, 42(6): 575-581. https://doi.org/10.19805/j.cnki.jcspe.2022.06.012
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In order to explore the comprehensive electrothermal performance of square-tube flat plate PV/T system, a mathematical model of electrothermal coupling system in a PV/T module was established according to the energy conversion process of the PV/T system. A performance evaluation method of the PV/T system under design condition was proposed to analyze the influence of key parameters on the system performance. And the variable condition characteristics of the PV/T system under different structures were compared. Results show that under the design condition, the electrical efficiency of PV/T system with multi and single square-tube is about 15%, and the total system efficiency is more than 78%. With the increase of solar radiation intensity, the temperature of photovoltaic panel and the outlet temperature of fluid increase in these two structures, which increase the total system efficiency subsequently. The electrical efficiency and total system efficiency can be improved by increasing the inlet volume flow rate or reducing the inlet temperature. Under the same operation condition, the total efficiency of single square-tube flat plate PV/T system is 3.1% lower than that of multi square-tube one,and the photovoltaic panel temperature of multi square-tube flat plate PV/T system is 9.72 K lower than that of single square-tube one. Therefore, better comprehensive performance is achieved by multi square-tube flat plate PV/T system.
    • Material Research
  • Material Research
    Microstructure Stability of Ni-Cr-Co Based Superalloy for Heavy-duty Gas Turbine
    ZHOU Biao, FU Rui, YAO Zhihao, ZHAO Shuangqun, WANG Yanfeng, XIE Xishan
    2022, 42(6): 582-588. https://doi.org/10.19805/j.cnki.jcspe.2022.06.013
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The equilibrium solidification structure of Haynes 282 alloy was calculated by Thermal-Calc software combined with Ni-based database, and the isothermal transformation curve (TTT curve) was provided. In addition, the microstructure of Haynes 282 alloy after long-term aging and rupture test was studied by using scanning electron microscope (SEM), transmission electron microscope (TEM), electron diffraction and comprehensive phase analysis method. Results show that TCP phase would precipitate from Haynes 282 alloy after long-term aging at 800℃. The acicular phase precipitated from Haynes 282 alloy is Mo enriched μ phase. At the temperature of 700~800℃, the size and content of μ phase precipitated from Haynes 282 alloy would increase with the rise of aging time and temperature, indicating the microstructure instability of Haynes 282 alloy under high temperature and long-term stress.