Power Equipment

Archive

  • 2019 Volume 33 Issue 1
    Published: 15 January 2019
      
  • Select all
    |
  • Numerical Simulation of the Re-entrainment Phenomenon in a Demister
    Zhang Bo, Gong Shishang, He Yuanzheng
    2019, 33(1): 1-5.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The main source of re-entrained droplets in a demister was numerically analyzed using FLUENT software, while the effectiveness of the treatment measures by installing different hooks in the demister was studied. Results show that the re-entrained droplets are mainly produced in the stripping and separation of liquid film, and the installation of double hooks can effectively inhibit the re-entrainment phenomenon.
  • Influence of Extraction Heating on the Wall Temperature of a High-temperature Reheater
    Hu Yinyin, Shen Qian
    2019, 33(1): 6-9.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The safety of a 660 MW ultra-supercritical extraction heating unit was analyzed by means of steam turbine thermal calculation, boiler thermal calculation and final reheater thermal deviation calculation. Results show that there are risks of overheating or tube burst in the unit after steam extraction for heating purpose. This may serves as a reference for similar units to extract steam from the inlet of high-temperature reheaters.
  • Design Optimization on Denitration Retrofit of a Coal-fired Boiler
    Wang Bosen
    2019, 33(1): 10-15.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To solve the problem of ash accumulation occurring in the process of denitration retrofit for a coal-fired boiler, an optimal design was proposed through quantitative and qualitative analysis of the flue ash accumulation using fluid mechanics principle. To overcome the space limitation of original steel column, the scheme to let the reactor outlet pass through the steel column was suggested, to which, a heat transfer analysis was conducted, thus to find the effects of insulation settings on the surface temperature of the steel column. Finally, a solution was presented to minimize the deviation of actual steel temperature from ideal design values.
  • Comparative Investigation on Steam Oxidation Resistance of TP347HFG and Inner Surface Shot-peened TP347H Austenitic Heat Resistant Steel for Boilers
    Li Jian, Ma Yunhai, Yang Xiaochuan, Yang Huachun
    2019, 33(1): 16-20.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Steam oxidation resistance tests of TP347HFG and inner surface shot-peened TP347H boiler tube samples were conducted at 650℃ and 27 MPa for different hours, while the cross section morphology, microstructure, elements distribution and phases of oxide layers were analyzed. Results show that the oxidation rate of TP347HFG follows the exponential oxidation rule. On the inner surface of shot-peened TP347H tubes, a thin layer of Cr-rich oxide film forms in most areas, while thicker island-like oxide film forms in local region. The inner layer of oxides on TP347HFG tubes mainly consists of (Ni,Fe) Cr2O4, and the outer layer is made up of Fe3O4 and Fe2O3, while Cr2O3 and FeCr2O4 are included in the oxides on inner surface shot-peened TP347H tubes. Comparatively, the inner surface shot-peened TP347H is proved to have better steam oxidation resistance than TP347HFG by the test.
  • Failure Analysis for Platen Reheater Tubes in a Power Plant Boiler
    Zhang Weini
    2019, 33(1): 21-24.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Reheater tube burst failures of a boiler were studied by macroscopic analysis, geometric measurement of thickness and weld, room-temperature mechanical property test and microstructure analysis, following which, the failures were found to be caused by stress concentration due to serious aging of the tube material and large reducing angles.
  • Failure Analysis for 15CrMoG Water Wall Tubes in a 600 MW Supercritical Unit
    Liu Chuanhuai, Liu Tao, Wang Wei, Ye Lin
    2019, 33(1): 25-27.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    By analyzing the reasons leading to the 15CrMoG tube blockage and overheat burst existing in the water wall of a 600 MW supercritical thermal power unit, the problem was found to be caused by peeling of oxide scales formed during tube manufacture and boiler operation, which was finally solved by taking the way of chemical cleaning.
  • Research Progress on Regenerable Sorbents for Mercury Removal from Flue Gas
    Li Na, Wei Hongqi, Duan Yufeng, Wang Chenping, Hu Peng, Liu Shuai, Zhao Longsheng
    2019, 33(1): 28-32.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    An introduction is presented to several kinds of regenerable mercury adsorbents, their support materials and corresponding modification methods, together with an analysis on the preparation process, adsorption property, deactivation features and regeneration mechanism, after which, some considerations are proposed for the research process, while the areas and trends of research are put forward.
  • Study on Dehydration of the Gypsum in a Wet Flue Gas Desulfurization System
    Wang Yonghui
    2019, 33(1): 33-36.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To solve the problem that the gypsum in a limestone-gypsum wet flue gas desulphurization (WFGD) system could not be well dehydrated during operation process, the effects of following factors on the dehydration of gypsum were analyzed, such as the operating condition, operation management, equipment output and slurry quality, etc. By taking corresponding countermeasures for different conditions, the WFGD system is now able to operate safely, with pollutants emission of the unit satisfying relevant standard, which may serves as a reference for other thermal power plants in dealing with similar circumstances.
  • Ammonia Injection Optimization for the SCR Denitration System of a 300 MW Coal-fired Unit
    Liu Jianhang, Zhang Shutong, Zhao Xu
    2019, 33(1): 37-40.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Taking the selective catalytic reduction (SCR) denitration system of a 300 MW coal-fired unit as an object of study, a comparison was made on its operating status before and after ammonia injection adjustment, together with an analysis on the reason of high consumption of liquid ammonia, and an optimization of the boiler operation mode, so as to reduce the consumption of liquid ammonia, enhance the safety and reliability of the SCR denitration system and to improve the economy of the unit, which may serves as a reference for ammonia injection optimization of similar units.
  • Optimization of an On-line Boiler Combustion Control System Based on CO Detection
    Wang Li, Wang Yanjin, Kang Jingqiu, Song Hongpeng, Zhou Xinyang
    2019, 33(1): 41-46.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Based on the detection of CO concentration in boiler flue gas, a combustion control system was established by analyzing the combustion condition of the boiler, summarizing the test method for air distributions, and applying the hot-state test curve, etc., after which, the control logic of air distribution was improved, the CO emission was controlled within a reasonable scope, the safety of boiler operation was secured and the efficiency of the boiler was improved.
  • Retrofit and Control of an Ultra-high Pressure Heating System in a 350 MW Unit
    Dai Jiangang
    2019, 33(1): 47-50.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    An introduction is presented to the retrofit on an ultra-high pressure heating system of a 350 MW unit, with focus on the thermal parameters, the control scheme and the feedwater system for the unit condenser required by the increase of heat supply. After retrofit, the heating capacity of the power plant to outside customers is promoted, the steam parameters are stabilized. This may serve as a reference for retrofit of heating systems of similar units.
  • Cause Analysis for Stall of a Boiler's Induced Draft Fan after Capacity Expansion Retrofit
    Wang Junmin, Ma Qilei
    2019, 33(1): 51-55.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    After the merging retrofit of an induced draft fan with a booster fan to expand its capacity in a power plant, stall failures occurred frequently to the induced draft fan in high-load operation period after retrofit, leading to load limit operation of the power generation set, on-site performance tests were conducted, after which, the problem was found to be firstly caused by the too low safety margin of the induced draft fan, due to its design performance curve being incompatible with the actual one, and secondly by the insufficient margin of air pressure and excessive margin of air flow rate, due to unreasonable selection of fan parameters. Based on analysis of above causes, some suggestions were proposed for further retrofit of the fan, which may serve as a reference for retrofit of similar ultra-low emission boilers.
  • Cause Analysis and Treatment of High Temperature on Non-working Face of Thrust Pad in a 300 MW Turbo-Generator Set
    He Donghui, Li Yang, Ye Zhenqi
    2019, 33(1): 56-60.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the problem that high temperature and negative axial displacement occurring in non-working face of thrust pad in a 300 MW steam turbo-generator set, a number of tests were conducted under different conditions, based on structural analysis of the turbine rotor and considering the structural features of the thrust pad, following which, the problem was found to be caused by the increase of negative axial thrust. The method of reducing the leakage from balance piston chamber to high pressure cylinder finally was adopted. The non-working face temperature of the thrust pad is now stabilized at about 80℃ after retrofit.
  • Energy Saving Retrofit for Condenser Vacuum Systems of Thermal Power Units
    Chen Xin, Cheng Shi, Zheng Mincong
    2019, 33(1): 61-64.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To retrofit the condenser vacuum system of three thermal power units for energy saving purpose, following two schemes were compared, one is to adopt steam injection pump, the other is to install Roots-water ring vacuum pump set. Experimental results show that considering the cold end performance and overall energy saving effects, the scheme to adopt Roots-water ring pump set is suitable for units with high requirement on vacuum tightness, while that using steam injection pump is applicable for units of large capacity with low requirement on vacuum tightness.
  • Fault Analysis and Treatment for the Exciter of a 9E Gas Turbine Unit
    Zhang Xuelin
    2019, 33(1): 65-68.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To clear the faults occurring in the generator exciter of a 9E gas turbine unit, an analysis was conducted on the shortcomings of the manufacturing process, the structure and the material of the exciter. The faults were finally removed by improving the manufacturing process, modifying the test method, and strengthening the equipment maintenance, which could effectively eliminate hidden dangers in the exciter, ensure safety operation of the unit, and therefore may serve as a reference for troubleshooting of similar problems.
  • Discussion on an Integrated Electrical Control and Management System for MSW Incineration Power Plants
    Wu Liang, Liu Yicheng
    2019, 33(1): 69-74.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    An integrated electrical control and management system (I-ECMS) was proposed for municipal solid waste (MSW) incineration power plants, by combining the ECMS with the network control system of booster station, controlling all the power circuit breaks in communication mode, controlling all the motors by the distributed control system with fieldbus technology, and monitoring all the automation equipment in the plant and booster station through Ethernet. The network reliability of the system has been verified by setting up a model for making telesignal and telecontrol experiments on the spot, and the system is proved to have high economical efficiency by a series of calculations.