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    Testing & Research
  • Testing & Research
    Calculation of Main Steam Flow in Various Control Valves of Steam Turbine
    ZHANG Bao, GU Zheng-hao, TONG Xiao-zhong
    2012, 26(6): 389-391.
    Abstract ( )   Knowledge map   Save
    To perform various analyses of steam turbine under varying working conditions, it is very important to acquire the main steam flow in related control valves. Based on accurate characterization of the main steam flow, and in combination of the law between steam flow and nozzle outlet pressure (oval relation), a model has been set up for calculation of steam flow in various control valves, with which relevant calculations are achieved. The case calculation for a 300 MW unit proves this method to be effective.
  • Testing & Research
    Exploration on Lignite Pre-drying Technology for Power Plants
    QIN Ling, LI Xiao-jiang, WANG Guang-pu, HU Xian-hui
    2012, 26(6): 392-395.
    Abstract ( )   Knowledge map   Save
    Aiming at the problems encountered by some power plants practicing lignite co-combustion, namely that the boiler load is restricted due to excessive moisture in the fuel coal, the lignite pre-drying technology is proposed for the purpose of reducing external moisture of fuel coal, which solves the contradiction between the boiler combustion equipment and high moisture level of lignitous coal. Taking the 1 025 t/h boiler of a 300 MW unit as an example, three configurations of the lignite pre-drying system are provided, of which the operating economy and safety assessments are conducted, so as to provide reference for related personnel.
  • Testing & Research
    Study on N2 Leakage of HP＆IP Combined Cylinder Turbine
    LI Gang , XU Jian-qun , GU Ling-zhi
    2012, 26(6): 396-399.
    Abstract ( )   Knowledge map   Save
    An introduction is being presented to the researches on N2 leakage of HP＆IP combined cylinder turbine both at home and abroad. It is proved that N2 leakage rates of the intermediate separation shaft seal under different working conditions are constants through the calculation and mathematical derivation to N2 leakage rates of a 600 MW supercritical turbine under different working conditions.
  • Testing & Research
    Failure Analysis on Drain and Spray Piping Supports for a 3 091 t/h Ultra Supercritical Boiler’s Body
    XIE Ning , JI Qing , WEN Ting-ying
    2012, 26(6): 400-402.
    Abstract ( )   Knowledge map   Save
    According to the support failure fault arising after boiler ignition test in the drain and spray piping of a 3 091 t/h ultra supercritical boiler’s body, an analysis has been carried out on the structural features of the drain and spray piping, together with an introduction to the methods to carry out stress analysis thereto, so as to find the failure causes and seek corresponding solutions, and therefore provide references for similar engineering projects.
  • Testing & Research
    Analysis and Study on Sealing Property of a Metal Sleeve for Nuclear Power Plants
    WANG Jing-xi, YU Gao-wei, ZHOU Yun-hua
    2012, 26(6): 403-406.
    Abstract ( )   Knowledge map   Save
    An introduction is being presented to the sealing structure of a metal sleeve applicable to equipments of nuclear power plants, together with an analysis on major factors influencing the sealing property. By adopting the method combining calculation analysis and experiments, researches have been carried out to key parameters that influence the sealing property of the structure, namely taper angle and taper angle difference. Key factors that affect the sealing property and their acting rules have been discovered successfully. It is proposed that the taper angle shall be selected as 45-65 degrees and the taper angle difference as 3-6 degrees preferably in engineering application.
  • Testing & Research
    Research on Economical Replacement Cycle of Gas Turbine Air Filters
    YANG Jia-ji
    2012, 26(6): 407-409.
    Abstract ( )   Knowledge map   Save
    In accordance with the economical replacement cycle of gas turbine air filters, an analysis is carried out on the operational characteristics of air filters, based on which a mathematical model for the economical replacement cycle is established and solved in combination with examples; through analysis on several factors influencing the economical replacement cycle, corresponding economical replacement cycles are obtained under different conditions when the maintenance expense is the minimum, or when the cost and electricity price are respectively increase by 10%.
  • Testing & Research
    Development and Application of Oval Parent Tubes and H-shaped Finned Tubes
    KOU Xing-zhuo
    2012, 26(6): 410-412.
    Abstract ( )   Knowledge map   Save
    Aiming at great gas resistance, soot formation, wear problems of traditional gas coolers, a gas cooler with oval parent tube and H-shaped finned tube has been developed. Wind tunnel simulation test and flow field analysis indicate that the gas cooler with oval parent tube has low gas velocity, small resistance, smooth streamline, and alleviated soot formation and wear. Operation results in a power plant prove the gas cooler of such type to be feasible.
    • Computer & Control
  • Computer & Control
    Matching Between Function Settings and Flow Characteristics of HP Governor Valve for Steam Turbines
    ZHOU Chang-wei, ZHU Xiao-jing, SONG Shao-wei
    2012, 26(6): 413-415.
    Abstract ( )   Knowledge map   Save
    Aiming at the problem of load fluctuation during sequence valve control after upgrading the governing-stage nozzle of No. 5 steam turbine of Heze Power Generation Co., Ltd., an analysis is carried out to various reasons causing the load fluctuation, together with a detailed introduction to the load fluctuation phenomenon due to the mismatching between flow characteristics and function settings in the DEH control logic. The problem of load fluctuation is solved through adjustments to flow function of the HP governor valve.
  • Computer & Control
    Comparison of Prediction Effects of Several Improved BP Neural Network Algorithms on Carbon Content in Fly Ash
    LI Lu, LI Bin, DU Yan-ling, XIE Yi-min
    2012, 26(6): 416-419.
    Abstract ( )   Knowledge map   Save
    An introduction is being presented to the momentum gradient descent algorithm, the L-M numerical optimization algorithm, and the Bayes algorithm, for the purpose of predicting the carbon content by mass fraction in the fly ash of a power plant, based on a newly proposed prediction model. Analysis and comparison results indicate that when the number of training samples is 30 or more, the momentum gradient descent algorithm tends not to converge; the convergence rates of L-M numerical optimization algorithm and Bayes algorithm are much higher than that of the momentum gradient descent algorithm. The prediction precision of Bayes algorithm, however, is the highest.
    • Material & Technology
  • Material & Technology
    Comparative Study on Different Specimen Preparation Methods for Performance Acceptance Test of PWR Nuclear Power Pressurizer Head
    YANG Jin-bing, MAO Shi-yong, YANG Wen, LAI Xian-hong, YU Ming-ming
    2012, 26(6): 420-424.
    Abstract ( )   Knowledge map   Save
    As for nuclear power pressurizer head manufactured from hot rolled plates, specimens were sampled at different positions from both simulated flat plate and head body, with which a whole set of comparative test was conducted in accordance with the requirements of RCC-M M2127. Results show that there is no significant difference in the performance between the simulated and actual specimens, and their microstructure characteristics are completely the same; the sampling from simulated flat plate can absolutely replace that from head body.
    • Operation & Retrofit
  • Operation & Retrofit
    Major Influencing Factors of Coal Consumption for Power Supply and Solutions
    ZHANG Xia-lin, WANG Jie-bin
    2012, 26(6): 425-427.
    Abstract ( )   Knowledge map   Save
    Aiming at reducing coal consumption for power supply and increasing the competiveness of power plants, an analysis has been conducted on current situations of the No.1 unit in a power plant, together with an introduction to technical measures adopted by the unit in the aspect of reducing power supply coal consumption, based on which some suggestions are proposed for future energy saving and consumption reduction by taking the existing coal conservation and consumption reduction potential thereof into account.
  • Operation & Retrofit
    Vibration Analysis and Improvement of Medium-pressure Bypass Valve in F Class Gas-Steam Combined Cycle Unit
    ZHANG Yi , ZHU Yong-qing
    2012, 26(6): 428-430.
    Abstract ( )   Knowledge map   Save
    In accordance with the high-frequency vibration in the medium-pressure bypass system of similar gas-steam combined cycle power plants, an analysis was performed on the vibration causes, and subsequently measures were proposed and taken, such as increasing the pressure of the steam to enter the condenser from the medium-pressure bypass valve, redesigning the medium-pressure bypass valve, and so on, after which obvious effects were obtained. This may serve as a reference for similar power units.
  • Operation & Retrofit
    Optimization Retrofit and Experimental Study on a Coarse Powder Separator
    HUANG Gang-ying, LI Yong-hua, YANG Xiao-hai
    2012, 26(6): 431-433.
    Abstract ( )   Knowledge map   Save
    Aiming at shortcomings of the axial coarse powder separator of a power plant, an optimization retrofit has been performed to the structure and parameters of the original coarse powder separator, while field tests and analysis carried out on the performance of the coarse powder separator before and after retrofit. Result show that the separation efficiency and pulverized coal uniformity of the dynamic separator as well as the boiler combustion are all improved after the retrofit.
  • Operation & Retrofit
    Optimization on Low NO X Combustion System of a 220 t/h Coal-fired Boiler
    HOU Hong-wei
    2012, 26(6): 434-436.
    Abstract ( )   Knowledge map   Save
    An introduction is being presented to the improvement retrofit and effects on the low NOx combustion system of a 220 t/h coal-fired boiler, together with analysis on problems such as serious slagging in cold ash hopper, damage of third tuyere, slagging of platen superheater, and deviation of NOx emission mass concentration, etc., emerged after the primary retrofit. Based on above analysis, secondary retrofit measures are put forward and taken with good effects obtained.
  • Operation & Retrofit
    Retrofit for Heating Capacity Improvement and Energy Saving of a 75 t/h Coal-fired Boiler
    MA Xin-min, JIANG Xiao-feng, WANG Jing-xi, ZHU Yi-fei
    2012, 26(6): 437-440.
    Abstract ( )   Knowledge map   Save
    Aiming at the requirement of a coal-fired power plant on heating capacity improvement and energy conservation, a retrofit plan has been proposed based on analysis of operating data and thermodynamic calculation, which realizes heating capacity improvement by decreasing the temperature of feed water and adopting the original regenerative extraction steam to supply heat directly, and achieves the energy saving and consumption reduction purpose through measures of adding a wall temperature-controllable heat exchanger and upgrading the economizer at the rear of the boiler. Via the retrofit, the boiler thermal efficiency is improved by 1.9%, while the heat supply capability increased significantly.
  • Operation & Retrofit
    Improvement on Static Ring of a ZGM113N Medium-speed Coal Mill
    ZHU Yong-chao , DONG Xu-hai , WU Yun-guo , WU Ying-hua
    2012, 26(6): 441-443.
    Abstract ( )   Knowledge map   Save
    Aiming at long-standing problems of serious wear, inconvenient maintenance, etc. of static rings for coal mills, a retrofit scheme was proposed on the structure of static rings, and a comparison of investment and returns was made before and after the retrofit. Results show that the improved structure of static ring is reasonable, with which expected objectives are reached.
  • Operation & Retrofit
    Application of Flexible Sealing Technology to Boiler Roof
    DU Chang-fei , YU Fei , ZHANG Rui-fen
    2012, 26(6): 444-446.
    Abstract ( )   Knowledge map   Save
    Aiming at the tearing problems occurring in top seals of a large-scale boiler due to thermal expansion and relative displacement, measures of adding flexible seal structure to the boiler roof are proposed. By analyzing the causes leading to frequent leakage at 3 positions on the roof, specific retrofit schemes are suggested from two aspects, namely material selection and construction process determination, following which an evaluation of retrofit return is performed.
  • Operation & Retrofit
    Cause Analysis on Explosion of Direct Firing Pulverizing System for a BBD-4360 Coal Mill
    SUN Lei , QU Hai-ying , ZHANG Jun
    2012, 26(6): 447-449.
    Abstract ( )   Knowledge map   Save
    Aiming at the explosion accident frequently occurring in pulverizing systems of power plants, by analyzing the explosion causes, the failure is found to be caused by over-high volatile content of coal, open fire resulted from friction among metal parts in the equipment, and spontaneous combustion of piled coal. Corresponding measures are proposed, such as adjusting operating parameters and retrofitting relevant equipment, so as to avoid the recurrence of explosion accident in the pulverizing system.
  • Operation & Retrofit
    Safety and Economy Analysis on Blowdown Method of Hydrogen Cooling System for Steam Turbo-Generator Sets
    ZHU Yan-ping, LI Xi-jun, WU Hong-bo, YANG Hong-bing
    2012, 26(6): 450-452.
    Abstract ( )   Knowledge map   Save
    An introduction is being presented to the problems of fast drop of hydrogen purity, and need of hydrogen filling or pollutant discharge due to continuous micro-leakage of hydrogen, which happens to the hydrogen system of a 600 MW steam turbo-generator set in operation. Improper blowdown method may produce hydrogen waste, slow hydrogen purity improvement, and bring great threatens to equipment and personnel. Further studies and discussion are made over the purity and pressure changes of hydrogen in hydrogen-filling and pollutant discharge process through the method of calculation, analysis and experimental verification, which shows that the safety and economy of continuous hydrogen filling and pollutant discharge are better than those of intermittent method at the same hydrogen consumption.
    • Environmental Technology & Equipment
  • Environmental Technology & Equipment
    MSW Incineration Gas Treatment Process Meeting EU 2000 Standard
    LI Jun, YAN Sheng-jun, CHEN Zhu, WANG Zhan-lei
    2012, 26(6): 453-455.
    Abstract ( )   Knowledge map   Save
    Aiming at the increase of requirement on treatment of MSW (municipal solid waste) incineration gas, a gas treatment process meeting the EU 2000 Standard is proposed, including the flow chart, the work process and de-acidification performance of every component, the wastewater treatment process and the reheating device. A description is presented to the consumptions of NaOH solution, Ca(OH)2 and active carbon in the treatment process, and to the parameters for type selection of the scrubber and fans, based on actual examples.
  • Environmental Technology & Equipment
    Design Essentials for Boilers Obeying EU Pressure Equipment Directive (PED)
    YIN Hui-kun, ZHU Xia
    2012, 26(6): 456-460.
    Abstract ( )   Knowledge map   Save
    An introduction is being presented to the requirements related to boiler design obeying EU Pressure Equipment Directive (PED), together with an analysis on the noteworthy items for boiler design and calculation according to PED, and a comparison of corresponding provisions among ASME, GB/T, and PED, which may serve as a reference for design and manufacture of boilers.