Power Equipment

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  • 2022 Volume 36 Issue 2
    Published: 15 March 2022
      
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  • Numerical Simulation Study on Flow Accelerated Corrosion Downstream of Throttle Orifice Plate for Carbon Steel Feedwater Pipeline of Secondary Circuit in a Nuclear Power Unit
    Zong Lingfeng, Zhou Keyi, Huang Junlin, Si Xiaodong, Xu Qinglan
    2022, 36(2): 75-82. https://doi.org/10.19806/j.cnki.fdsb.2022.02.001
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Computational fluid dynamics method was used to simulate the flow field distribution downstream of the throttle orifice plate for carbon steel feedwater pipeline of secondary circuit in a nuclear power unit. The effects of inlet flow rate and chamfer angle on the flow field and mass transfer coefficient distribution downstream of the throttle orifice plate were studied. Based on the Sanchez-Caldera flow accelerated corrosion (FAC) prediction model, the correlation between FAC rate downstream of the throttle orifice plate, as well as its distribution, and inlet flow rate and chamfer angle was investigated. The results show that the simulation data correlate well with the experimental data. When the chamfer angle is constant, the mass transfer coefficient and FAC rate exhibit an overall upward trend with the increase of inlet flow rate, while the peak position of FAC rate shifts slightly downstream. When the inlet flow rate is constant, the decrease of the chamfer angle makes the peak position of FAC rate close to the orifice plate, and the mass transfer coefficient and FAC rate peak are the lowest when the chamfer angle is 45°.
  • Unsteady Thermal Equilibrium Analysis of Medium Speed Coal Mill in Utility Boiler
    Chen Tuo, Shen Yueliang, Li Debo, Zhou Jielian, Cheng Mingtao, Zhong Jun, Feng Yongxin, Liao Hongkai
    2022, 36(2): 83-87,99. https://doi.org/10.19806/j.cnki.fdsb.2022.02.002
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    Aiming at a coal mill deflagration accident caused by coal interruption in a power plant, the unsteady heat transfer process of coal powder in coal mill after coal interruption is calculated by field test and analysis. The heating characteristics of pulverized coal temperature in coal mill were obtained, and the reason of deflagration was analyzed. The measures to prevent coal deflagration were put forward, which provided reference for safe and stable operation of coal mill in power plant.
  • Heat Transfer Analysis of Basalt Fiber Bundle Heat Accumulator with Mixed Flow Channels
    Xu Jingwen, Kuang Rao
    2022, 36(2): 88-92. https://doi.org/10.19806/j.cnki.fdsb.2022.02.003
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The effects of fiber bundle arrangement and distance between adjacent fiber bundles in a fiber bundle group on the heat transfer performance of a basalt fiber bundle heat accumulator with mixed flow channels were analyzed by numerical simulation. The results show that the ideal heat transfer efficiency of the basalt fiber bundle heat accumulator can be obtained when the distance perpendicular to the gas flow direction between adjacent fiber bundles is 7.2 mm, the distance parallel to the gas flow direction is 4.2 mm and the fiber bundle group has an in-line arrangement. Compared with honeycomb ceramic heat accumulator, it is compatible with higher gas flow rate which can improve the gas effective heat transfer efficiency under the premise of effective heat transfer and lower pressure drop.
  • Numerical Study on the Effect of Mechanical Ventilation in Tower on Flue Gas Diffusion of the Three Incorporate Towers System
    Cai Ningning, Ma Huan, Dong Yunshan, Si Fengqi
    2022, 36(2): 93-99. https://doi.org/10.19806/j.cnki.fdsb.2022.02.004
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To solve the problem of flue gas diffusion in the three incorporate towers system, a three-dimensional model was established by means of computational fluid dynamics, and the flue gas lifting height and flue gas diffusion effect before and after coupling mechanical ventilation were compared and analyzed. The results show that the lifting height of flue gas outside the tower is inversely proportional to the ambient wind speed, and the diffusion area of flue gas inside the tower is directly proportional to the ambient wind speed. With the mechanical ventilation arranged in the tower, the lifting height of flue gas outside the tower increases, the flue gas inside the tower diffuses evenly, and the comprehensive coal consumption of the unit decreases.
  • Fracture Failure Analysis of 22Cr12NiWMoV Blade of Small Turbine in a 1000 MW USC unit
    Xu Kai, Shi Xiaoxi, Liu Weiping, Zhao Minghua, Gu Shuchao, Wang Jiahe
    2022, 36(2): 100-105,110. https://doi.org/10.19806/j.cnki.fdsb.2022.02.005
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The fracture failure analysis of 22Cr12NiWMoV blade of feed pump turbine (small turbine) of 1000 MW USC steam turbine was carried out by means of macroscopic observation, metallographic analysis, mechanical property testing and tensile/impact fracture surface analysis in a scanning electron microscope(SEM). The results show that the microstructure of the blade is coarse and the grain size is obviously over-heated. The macro hardness is higher than the standard value. Decrease of the impact toughness shows that the blade material is hard and brittle. It is considered that the cause of blade cracking is that the overheat brittleness caused by poor production process, and the fracture failure occurred at the stress concentration area.
  • Effects of Heat Treatment Temperature on the Steam Oxidation Behavior of S30432 Shot-blasted Steel Tube
    He Sifan, Liu Chen, Li Nan, Yang Shouen
    2022, 36(2): 106-110. https://doi.org/10.19806/j.cnki.fdsb.2022.02.006
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    By means of optical microscope, X-ray diffractometer, scanning electron microscope and energy dispersive spectrometer, after the steam oxidation test in 620 ℃, analyses were conducted on morphology characteristics of the inner wall shot-blasted layer and oxide of S30432 steel tube samples with different heat treatment temperatures and without heat treatment. Results show that the oxidation kinetics curve of each S30432 shot-blasted steel tube sample is close to the parabolic rule, and the surface oxide film thickness is very thin; while the oxide film phase is mainly composed of Cr2O3, (Fe, Cr)3O4, (Fe, Cr)2O3 rich Cr phase and a small amount of Fe3O4. With the heat treatment temperature of 650760 ℃, there is no obvious effect on the steam oxidation behavior of S30432 steel tube shot-blasted layer. After the heat treatment at 730760 ℃, the anti-oxidation property of austenitic steel shot-blasted tube in boiler high temperature surface would not be reduced, which can satisfy the safety requirement of long-term service.
  • Research on the Performance of Domestic PEEK Insulating Material for Electrical Penetration Assemblies
    Shen Peng, Quan Xiande, Wu Keke, Fu Fengnian, Huang Wenjun, Kuang Zhenhua
    2022, 36(2): 111-114,121. https://doi.org/10.19806/j.cnki.fdsb.2022.02.007
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    An experimental research was conducted on the basic performance and the radiation resistance performance of a domestic polyetheretherketone (PEEK) insulating material, and the performances of the domestic material and the imported material were compared. Results show that the basic performance parameters of the insulating material all can satisfy the using requirements, and through the experiments with different doses, the insulating material exhibits a better radiation resistance performance. The performance of the domestic material is similar to that of the imported material, and therefore the domestic material can instead of the imported material.
  • Study on CO2/H2O Power Cycle Integrating with Supercritical Water Coal Gasification and CO2 Capture
    Zhao Wenjuan, ChenYaping, Wu Jiafeng, Zhu Zilong, Lü Haonan
    2022, 36(2): 115-121. https://doi.org/10.19806/j.cnki.fdsb.2022.02.008
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Based on supercritical water coal gasification technology, a gas and steam hybrid working medium power cycle (GSMC-C cycle) with supercritical water gasification syngas/O2 combustion products plus circulating H2O as the circulating working medium integrating was proposed and studied, which with the feature of high efficiency, CO2 capture, peak shift energy storage, and low pollutant discharge. The effects of key parameters on cycle performance were studied by numerical simulation. The supercritical water and heat in the gasifier were provided by the system, and the cooling energy of liquid oxygen was used to realize the liquefaction and capture of CO2. The results show that the net efficiency and gross efficiency of GSMC-C cycle are 41.34% and 48.06% respectively when the inlet parameters and condensation parameters of ultra-high pressure turbine are 30 MPa/650 ℃ and 30 kPa/30 ℃, the unit oxygen production power consumption of ASU is 0.245 kW·h/kg, and the total CO2 capture parameters are 4 MPa/5 ℃.
  • Optimization on Non-nuclear Steam Rolling of Turbine with Sodium Cooled Fast Reactor
    Zuo Chuangju, Sun Wenzhao, Li Baoting, Gao Yufeng, Li Meng, Zeng Naisong
    2022, 36(2): 122-125,144. https://doi.org/10.19806/j.cnki.fdsb.2022.02.009
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    For the non-nuclear steam rolling of a turbine with a sodium cooled fast reactor, an optimization method was proposed by adding some pipelines and valves after the condensate polishing system, so as to recycle the desalinated water directly discharged into the waste liquid collection system in the original method. With adopting the optimization method, the safety of the turbine can be improved, while the cost can be saved by about 1.806 million yuan in the lifetime.
  • Research on Power Prediction Method of a Nuclear Power Turbine Generator Unit
    Bao Xudong, Cai Chao, Si Xianguo, Wei Anze, Liu Qiang, Li Wei, Wu Kaiyu
    2022, 36(2): 126-130. https://doi.org/10.19806/j.cnki.fdsb.2022.02.010
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Advanced machine learning algorithms were used to establish the monitoring, time series forecasting and regression calculation models of important state parameters of the unit operation.The optimization program of the output power curve of the nuclear power unit was developed. This program extracted characteristic parameters from the historical operating data of the unit, established a calculation model based on time series forecasting and random forest algorithm, and conducted training and regression calculations on the collected historical data of the unit to realize the prediction and advance warning of the operating parameter status of the nuclear power unit. On-line test results show that the on-line monitoring function is normal and the trend forecast for the next 12 h can be obtained, which can provide an optimized adjustment operation for the unit output power.
  • Study on Energy-saving Method of Fans under Deep Peak Shaving of a Thermal Power Unit
    Li Haoran, Ma Yuhua, Guo Xuetao
    2022, 36(2): 131-135. https://doi.org/10.19806/j.cnki.fdsb.2022.02.011
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In view of the current situation of low load rate and deep peak shaving of large-scale thermal power units, the low-speed drive fans retrofit technology is proposed, and the low-speed drive device is developed to realize the energy saving of fans in air-gas system under low load conditions. The results show that the low-speed drive fans retrofit scheme can improve the operation stability of the air-gas system, and has obvious economy and safety.
  • Fault Analysis and Treatment of Thrust Bearing in Hydro-turbine Generator Units
    Yan Yuncheng, Wang Wenhuan, Zhang Sai, Zhou Zhenglong, Min Zhankui, Liu Xiuliang, Wang Haojun, Pan Weiguo
    2022, 36(2): 136-140. https://doi.org/10.19806/j.cnki.fdsb.2022.02.012
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    The thrust bearing of hydro generator set is prone to excessive temperature and burnout during operation, which seriously affects the normal rotation of generator shaft system and the stable and safe operation of the unit. The failure of thrust bearing of hydro generator set caused by high temperature of thrust bearing shaft tile due to vibration of the unit, design structure, processing and installation and lubricating oil cooling system is analyzed, and the related improvement methods are summarized, so as to avoid the hidden danger for the safety of hydro power station due to the failure damage of thrust bearing, and providing reference for hydro power station to deal with similar failure.
  • Analysis and Treatment on Abnormal NOx Emission after Fuel Valve Retrofitting in an F-class Gas Turbine
    Li Feng, Li Yongchao
    2022, 36(2): 141-144. https://doi.org/10.19806/j.cnki.fdsb.2022.02.013
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    To solve the problem of the abnormal high oxynitride (NOx) emission after the fuel valve retrofitting in an F-class gas turbine, analyses were conducted on the influencing factors, and corresponding treatments were carried out. Results show that,with the optimization on the control logic algorithm of the fuel valve, the gas flow can be reduced accordingly, while the NOx emission can be restored to a normal range.
  • Optimization and Transformation of a 250 t/d MSW Incineration Boiler
    Huang Shucui
    2022, 36(2): 145-148. https://doi.org/10.19806/j.cnki.fdsb.2022.02.014
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In order to cope with the increase in the calorific value of waste, a 250 t/d domestic waste incineration boiler was conventionally expanded. The boiler transformation did not achieve the expected results due to the failure to reasonably consider the boiler arch, fan air pressure and other issues. At the same time, after the implementation of waste classification, the problem of boiler coking has become more prominent, which seriously affects the continuous operation ability of boiler. Through the analysis of the above situation, it is proposed to implement the reconstruction from the aspects of rear arch dip angle, secondary wind disturbance and so on, and finally achieve the expected effect.