Power Equipment

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  • 2019 Volume 33 Issue 2
    Published: 15 March 2019
      
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  • Technical Features and Application Effectiveness of Air-cooled High-parameter Steam Turbines
    Shi Jinyuan, Wang Weimin, He Aping, Zhang Hongtao, Pan Jiacheng, Whang Shudong, Chen Hongxi, Huang Qinghua, Fan Xiaoping, Zhu Haiyi, Fan Xuefei
    2019, 33(2): 75-79.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    An analysis was conducted on the technical features of air-cooed high-parameter steam turbines, such as the structure, flow capacity, specific last stage blades, floor-standing bearing pedestal and the back pressure protection, etc., together with an introduction to 6 typical domestic products of air-cooled high-parameter steam turbines, and a calculation on the upper limit of heat rate for air cooled high-parameter steam turbines with different air-cooling systems as well as the water saving rate of 18 air-cooled high-parameter steam turbines in operation. Results show that better water saving effectiveness could be achieved by adopting air-cooled high-parameter steam turbines, which therefore may serve as a reference for similar units.
  • Numerical Simulation on the High-pressure Dense-phase Pneumatic Conveying of Pulverized Coal Considering Gas Compressibility
    Cai Haifeng, Xiong Yuanquan, Zhou Haijun
    2019, 33(2): 80-85.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To study the effect of compressibility of conveying gas on the gas-solid two phase flow in the conveying pipeline, a multiphase flow model was established considering gas compressibility, which was used to compare the two-phase flow under compressible and incompressible conditions. Results show that: compared with the incompressible gas-solid two-phase flow model, the gas phase compressible model increase the two-phase velocity in the pipe center and the two-phase fluctuation velocity near the tube wall, in which case, the flow disturbance is enhanced.
  • Research on Compression Ratio Distribution of an Extraction System with Combination Vacuum Pumps for the Condenser
    Zhu Lingyu, Wang Jun, Wu Zhengyong, Lu Chengbin, Yao Yongling, Yang Jianming
    2019, 33(2): 86-90.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To solve the problems concerning the water-ring vacuum pump for the extraction system of the turbine condenser, like being easily affected by the temperature of operating liquid and always with high power consumption, a new extraction system was proposed based on the combination of Roots vacuum pump and water-ring vacuum pump, and subsequently a mathematical model was set up for the extraction system. The effects of compression ratio distribution on the power of the two-stage pump system were then analyzed at different pressures of the turbine condenser. Results show that the extraction power can be reduced with the application of combination vacuum pumps for the extraction system, and there exists different optimal compression ratio distributions in different seasons.
  • Wide Load Combustion Adjustment Tests for the Pulverizing System of a 1 000 MW Boiler
    Pang Kaiyu, Dong Jianxun, Wang Xuexin, Chen Kun, Cai Wenqi, Li Yonghua
    2019, 33(2): 91-94.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Taking the pulverizing system of a 1 000 MW supercritical boiler as an object of study, combustion tests were conducted with focus on the operation indexes of the pulverizing system, so as to study the effects of the performance changes of the system on the combustion characteristics of the boiler, and to analyze the influence of coal fineness R90 on the boiler operation at different power loads. Optimal operation conditions were finally obtained for the pulverizing system, when the influence of power load on the combustion condition could be minimized.
  • Research on the Operation Mode of a Regenerative Feed Pump Turbine
    Liao Xianwei, Wang Changshuo
    2019, 33(2): 95-99,107.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A full scope simulation model was established for a regenerative feed pump turbine using Labview software, based on which, verification tests and comparative analysis were conducted on the coordinated operation mode of the regenerative feed pump turbine with the main turbine. Results show that with the reduction of unit load, the decreasing amplitude of the feed pump is higher than that of the feed pump turbine; adopting the operation mode of combined back pressure regulation with inlet steam throttling can not only meet the requirements of power matching, but also ensure the efficient and economic operation of the unit.
  • Thermal Performance Analysis of a Dish Solar Power System Based on Brayton Cycle
    Liu Deli, Wang Jun, Xu Zhicheng
    2019, 33(2): 100-102.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A 70 kW solar power generation system was retrofitted from its original tower type into dish pattern, of which the thermal efficiency and gas consumption were analyzed respectively under simple cycle, regenerative cycle and gas-solar combined cycle conditions. Results show that the most optimal scheme is the combined cycle, and when the outlet air temperature of receiver improves from 600 ℃ to 920 ℃, the system efficiency would be increased from 22.23% to 44.06%, and the recovery period of added investment would be relatively short.
  • Stress Evaluation and Test Verification of Electrical Penetration Assemblies in Nuclear Power Plants
    Zhu Youjun
    2019, 33(2): 103-107.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    ANSYS finite element software was used to analyze the mechanical behavior of electric penetration assemblies under various working conditions, and the analysis results were subsequently verified by dynamic performance tests. On this basis, stress analysis and evaluation were carried out on relevant assemblies according to the RCC-M code, which may serve as a reference for the design of electrical penetration assemblies in containment structures of nuclear power plants.
  • Condition Monitoring and Fault Diagnosis for the Horizontal Pump Package in a Nuclear Power Plant
    Bu Jiangtao, Guo Guangyue
    2019, 33(2): 108-111.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Condition monitoring and fault diagnosis were conducted for the horizontal pump package in a nuclear power plant, including the selection of monitoring parameters, researches of condition monitoring, and methods of fault diagnosis, etc. Common monitoring parameters of the horizontal pump package were determined, while an experimental software/hardware test platform was built up, based on which, verification tests were carried out, proving the prediction accuracy to be higher than 90%.
  • Interception Technology for Large Particles from Flue Gas of SCR Denitrification Systems in Supercritical Units
    Liu Xinian, Tang Jing, Zhang Jiakuan, Jiang Yong, Zhong Shaowei, Wang Shuo
    2019, 33(2): 112-114,118.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To solve the blocking problem existing on the surface of catalysts caused by large particles entrained by flue gas, which has negative effect on operation of the selective catalytic reduction (SCR) denitrification system, following countermeasures were proposed and taken, such as optimizing the design of flow path flow field, adding pleated interception screen as well as installing soot blower, etc. Results show that after taking above countermeasures, the large particles can be captured effectively before the flue gas flowing into the SCR denitrification unit. This may service as a reference for similar units to deal with the blocking problem in relevant catalysts.
  • Application of Environmental Protection Retrofit Schemes for Low-pressure Small-volume CFB Boilers
    Li Erxin, Zhang Longfei, Wei Fei, Wang Te
    2019, 33(2): 115-118.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To guide the selection of environmental protection retrofit schemes for low-pressure small-volume circulating fluidized bed (CFB) boilers, performance tests were conducted on 3×75 t/h CFB boilers in a thermal power plant after the implementation of retrofits respectively for the denitration, desulfurization and dust collection unit. Results show that, by adopting the high efficiency low NOx combustion technology, the limestone-gypsum wet flue gas desulfurization (WFGD) system and the bag filter, the goal of retrofit has been reached, under the premise that corresponding facilities work stably.
  • Discussion on Intergranular Corrosion Tests for S30432 Austenitic Heat-resistant Boiler Tubes
    Jiang Ping, Dong Meng, Zeng Hui, Liu Hongjie
    2019, 33(2): 119-121,132.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The reasons for infeasibility of sensitizing treatment for S30432 heat-resistant boiler tubes during intergranular corrosion test have been stated through such aspects as intergranular corrosion mechanism, features of S30432 austenitic heat-resistant tubes and intergranular corrosion test methods, etc. In addition, measures for preventing intergranular corrosion of S30432 heat-resistant tubes are proposed in the process of fabrication, transportation, site storage and operation of the boiler.
  • Analysis and Application of Association Rules in Power Plant Operation Optimization
    Zhang Lei, Ding Shifa, Yang Kaixuan
    2019, 33(2): 122-126.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Taking the wall temperature optimization of a power plant boiler as an example, the combined method of feature grouping and Apriori algorithm was used to find out the control parameters associated with the thermal deviation among pipe panels and to excavate the items of sensitive parameters. The results of excavation were in good agreement with actual measurements, and the optimization effectiveness on the wall temperature could be improved by 17% based on the association rules. This may serve as a reference for operation adjustment of similar power plants.
  • Optimized Design and Application of the RB Logic for a 1 000 MW Unit
    Yang Xiaolong, Shu Jianjun, Tao Xin
    2019, 33(2): 127-132.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To realize the run back (RB) control for a 1 000 MW unit, an optimized design was conducted on the pressure control logic, and the optimization effectiveness was verified by RB tests. Results show that after optimization, the decreasing amplitude of main steam temperature lies in a reasonable range, and the opening of high-pressure control valve does not change frequently; the target load of unit would be recovered swiftly when malfunctions of auxiliary parts occur, while various parameters keep unchanged.
  • Deep Peak Shaving Tests and Optimization for Thermal Power Units
    Wang Li, Wang Yanjin, Li Zhanguo, Song Hongpeng, Zhou Hongmei
    2019, 33(2): 133-137.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To improve the safety and flexibility of a thermal power unit, some optimization measures were taken for the power side deep peak shaving tests by comprehensively considering the factors of combustion safety, energy saving effectiveness, unit efficiency, auxiliary equipment output limit and AGC control strategy, etc. Results show that the scheme proposed can help to complete the parameter optimization and comprehensive benefit optimization in a short time, quantify the operation margin of boiler at low load, exploit the potential of deep peaking regulation for thermal power units, which therefore may serve as a reference for similar tests and technical retrofits.
  • Cause Analysis and Treatment on Low-temperature Reheater Steam Piping Abnormal Expansion a 300 MW Unit
    Li Ying, Tang Lu
    2019, 33(2): 138-141.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To solve the problems of abnormal thermal expansion of low-temperature reheater steam piping and wrong indication of relevant constant spring hangers, on-site inspections and stress analyses were conducted, and the problems were subsequently found to be caused by unreasonable connection way of the snubber and by corrosion at rolling part of the hangers, which inhibit the downward movement of the tubes. Above problems were finally solved by replacing involved snubber and constant hangers at inlet of the low-temperature reheater. This may serve as a reference for the design of similar snubber.
  • Operation Optimization of Circulating Water Pumps in a 400 MW Gas-Steam Combined Cycle Unit
    Yang Qiuhui, Huang Gongwen
    2019, 33(2): 142-145.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Operation optimization tests were conducted in different seasons on four circulating water pumps in a 400 MW gas-steam combined cycle unit after frequency conversion retrofit, so as to find out the optimal energy-saving operation mode of the pumps and to draw switching curves from two-pump operation to three-pump operation. Results show that there are different optimal operation modes for circulating water pumps in different seasons. This may serve as a reference for the operation of similar power units.
  • Desuperheating Water Intake Point Switching Analysis for the Superheater of a 300 MW Unit
    Liu Nan, Zhou Zhou
    2019, 33(2): 146-148.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To study the feasibility of switching the intake point of desuperheating water from feed pump outlet to HP heater outlet of a 300 MW unit, an analysis was conducted on the economy and safety of the retrofit with specific unit parameters. Results show that the retrofit may help to improve the operation economy of the unit, but may impact its operation safety. This may serve as a reference for future retrofit of similar units.