Power Equipment

Archive

  • Select all
    |
    Testing & Research
  • Testing & Research
    Study on Characteristics of a Dry/Wet Hybrid Cooling System under Variable Working Conditions
    Tang Tao, Xu Jianqun, Wei Hongqi
    2013, 27(5): 301-305.
    Abstract ( )   Knowledge map   Save
    A mathematical model was set up for calculating the exhaust steam pressure of a dry/wet hybrid cooling system under variable working conditions. Taking a 300 MW dry/wet hybrid cooling system as an example, the influence of following factors on the exhaust steam pressure was analyzed, such as the dry-bulb temperature, the ambient humidity, the face velocity in air cooling island and the exhaust volume of unit, etc., while the characteristics of its cold end studied, which may serve as a theoretical basis for improving the safety, economical efficiency and performance of the dry/wet hybrid cooling system.
  • Testing & Research
    Mechanism Analysis of Pool-boiling Liquid Backflow in Thin Porous Coatings
    Yun Panfeng, Shi Lin, Jin Zhonghua, Yang Peijun
    2013, 27(5): 306-310.
    Abstract ( )   Knowledge map   Save
    To study the pool-boiling liquid backflow mechanism in thin porous coatings, pool-boiling experiments of smooth surface and different porous coatings were conducted to obtain corresponding bubble boiling characteristics and pool boiling curves. Combined with experimental results, maximum liquid backflow speed and capillary limit in the thin porous coatings were calculated, while the formation mechanism of both the liquid backflow and capillary limit analyzed. Results show that there exists curved liquid membrane in porous coatings, and local dry is hard to appear due to higher liquid backflow speeds; the higher the capillary pressure and permeability of porous medium, the better the liquid backflow effect; lack of liquid backflow in single point will lead to more nucleation points, and if the liquid backflow is still inadequate, local dry will occur, that is capillary limit.
  • Testing & Research
    Application of Three-in-One Induced Draft Fan in a 1 045 MW Thermal Power Generation Unit
    Li Debo, Di Wanfeng
    2013, 27(5): 311-315.
    Abstract ( )   Knowledge map   Save
    An introduction is being presented to the three-in-one two-stage adjustable blade axial flow induced draft fan for the simultaneous use of flue gas denitration system and no-bypass flue gas desulfurization system in a power plant. It is pointed out that for 1 000 MW class power units, it is feasible to combine the denitration booster fan, the desulfurization booster fan and the boiler induced draft fan into an integral one. Problems concerning the safety and reliability of unit operation during the use of three-in-one induced draft fan are proposed, which may serve as a reference for the selection, commissioning, operation and improvement of auxiliaries for large thermal power plants.
  • Testing & Research
    Localization of Air Processing Module for Gas Turbines
    Wu Zhenyu, Liu Wangkou, Gu Huanian
    2013, 27(5): 316-318.
    Abstract ( )   Knowledge map   Save
    An introduction is being presented to the research and development of turbine auxiliaries in large-scale gas turbine combined cycle power units, such as the air processing module, etc., together with an analysis to system flowchart of the air processing module and technical parameters of relevant main components, which may serve as a reference for integral localization of gas turbine-generator sets and for construction of domestic gas turbine combined cycle power units.
  • Testing & Research
    ID Eddy Current Detection for Condenser Titanium Cooling Tubes in Convention Island of Nuclear Power Stations
    Ren Yifeng, Chen Jiansheng
    2013, 27(5): 319-321.
    Abstract ( )   Knowledge map   Save
    Based on analysis and study of the statuesque of lack of domestic and foreign standards for ID eddy current detection on ID and OD surface of condenser tubes in conventional island of nuclear power stations after tubing, expansion and welding process, the limitation of the test method is presented.
    • Computer & Control
  • Computer & Control
    Study on Dynamic Behaviors Model of Superheater and Reheater for Supercritical Power Units
    Li Xiaoxue, Gao Sheng, Li Xu, Xiao Bole
    2013, 27(5): 322-325.
    Abstract ( )   Knowledge map   Save
    To overcome the difficulty in obtaining good control effects for supercritical power unit due to the great lag characteristics of its superheated and reheated steam temperature, a method was proposed for establishing superheated and reheated steam temperature transfer function according to the structural and thermal parameters of boiler superheater and reheater, based on which the dynamic behaviors of superheater and reheater were quantitatively calculated for large-capacity once-through boilers, so as to provide convenience for power plants to perform control system simulation and to further improve the control quality of the system. Comparison results between calculated data with the newly built model and actual measurements prove the method to be facile and accurate. 
  • Computer & Control
    Tracking Study on Maximum Power Output of an Independent Photovoltaic Power Generation System
    Chen Hui, Wang Mingchun
    2013, 27(5): 326-329.
    Abstract ( )   Knowledge map   Save
    To overcome the deficiency of conventional Maximum Power Point Tracking (MPPT) algorithm for its low tracking speed and high misdiagnosis rate, a prediction method is put forward based on Support Vector Machine (SVM), which takes the data of a certain day as the training sample set to be trained by SVM and the trained model will subsequently be used for prediction of the maximum power point. Simulation results show that the SVM method can well predict the maximum power point, which therefore may serve as a reference for prediction of photovoltaic power generation systems.
  • Computer & Control
    Optimization of a SCR Denitration Control System Based on Soft-Sensing of Flue Gas
    Hu Changmei, Deng Yu, Wang Xuewen
    2013, 27(5): 330-333.
    Abstract ( )   Knowledge map   Save
    An introduction is being presented to the scheme and working principle of a SCR denitration control system based on soft-sensing of flue gas according to coal feed rate, to which an optimization is carried out to solve the problems, such as large escape of ammonia, high time lag of control system and varied coal quality, etc. Results show that the mass concentration of NOx emission can be controlled within 160~200 mg/m3 after optimization, with an error in ±15 mg/m3.
    • Operation & Retrofit
  • Operation & Retrofit
    Application of Impulse Soot Blower in CFB Boilers
    Li Yuzhong, Zhang Youshi, Wei Ruijun, Ling Baohui, Ma Xiaoqian
    2013, 27(5): 334-337.
    Abstract ( )   Knowledge map   Save
    To solve the problems of serious ash deposition on heat surface in boiler rear flue gas duct and the high exhaust gas temperature, and to choose most effective soot blowers, the working principles of various soot blowers are analyzed and compared, after which a retrofit scheme is proposed by using the impulse soot blower to replace the original steam one. Practices show that the application of impulse soot blower not only reduces the exhaust gas temperature but also saves high-quality steam and therefore reaches the purpose of energy conservation and consumption reduction.
  • Operation & Retrofit
    Retrofit on Low-nitrogen Combustion System of PG9171E Gas Turbines
    Zhou Guoxing, Huang Hongyan, Zhou Hui
    2013, 27(5): 338-342.
    Abstract ( )   Knowledge map   Save
    Combing with the oil-to-gas retrofit for a 300 MW gas-steam combined cycle unit, an introduction is being presented to the source of NOx in the exhaust gas of turbine, and to several low-nitrogen combustion technologies, including the principle, structure, combustion mode and control strategy of its DLN1.0 system. Moreover, causes leading to mode switching faults in unit commissioning, large unit vibration and load wobbling in the mode switching were analyzed and treated. Retrofit results show that the mass fraction of NOx emission from the gas turbine is less than 1.0×10-5, which meets relevant environmental requirements.
  • Operation & Retrofit
    Development and Treatment of Water Wall Leakage Caused by Under-deposit Corrosion
    Zhang Zongtang
    2013, 27(5): 343-344.
    Abstract ( )   Knowledge map   Save
    An introduction is being presented to three patterns of water wall leakage caused by under-deposit corrosion, such as swelling, cracking and tube burst, etc., to which chemical cleaning is suggested in the primary stage of under-deposit corrosion, and the significance is emphasized to diagnose and treat the defects of water wall under-deposit corrosion with modern nondestructive testing technologies.
  • Operation & Retrofit
    Cause Analysis and Treatment of Blockage Failures in Attemperating Water Control Valve of a Boiler Superheater
    Feng Zhiyu, Zhou Yu, He Xiong, Zhang Lianshuang
    2013, 27(5): 345-348.
    Abstract ( )   Knowledge map   Save
    An introduction is being presented to the blockage situation in the superheater attemperating water control valve for a 1 000 MW ultra-supercritical boiler in Beijiang Power Plant. It is found by analysis that the main cause of blockage comes from the Fe3O4 separated in water under certain temperature and pressure conditions. Corresponding countermeasures are proposed by taking into account the actual conditions, among which following measures are effective, i.e. oxygenating the feed water and changing the structure of the valve cage. 
  • Operation & Retrofit
    Cause Analysis and Preventive Measures for Shaft Seal Locking Faults of a 1 000 MW Turbine
    Yao Changmo, Wang Guoqi, Qu Ziyi
    2013, 27(5): 349-351.
    Abstract ( )   Knowledge map   Save
    Aiming at an accident occurring in a 1 000 MW turbine unit caused by shaft seal locking faults, an analysis is made to the structure and control of the shaft seal system, and subsequently corresponding preventive measures are put forward and taken, which have guaranteed the safety and economic operation of the unit.
  • Operation & Retrofit
    Cause Analysis and Treatment of Low Vacuum Degree in Generator Sealing Oil System of a 1 036 MW Unit
    Zhang Weijiang
    2013, 27(5): 352-354.
    Abstract ( )   Knowledge map   Save
    An introduction is being presented to the structure and function of the generator sealing oil system in a 1 036 MW unit, together with an analysis performed to the problems occurring during installation and commissioning stages, such as low vacuum degree of the sealing oil system, etc. Corresponding countermeasures are taken to the vacuum pump, which have effectively prevented the hydrogen in generator from being polluted by air and water carried by sealing oil, simultaneously, rational suggestions are proposed for the installation and maintenance of relevant equipment.
  • Operation & Retrofit
    Cause Analysis and Treatment of Fouling in Flow Path of 600 MW Supercritical Steam Turbines
    Shan Wenhao, Zhu Zhijian
    2013, 27(5): 355-357.
    Abstract ( )   Knowledge map   Save
    To solve the problems of serious fouling and corrosion in flow path of high- and low-pressure cylinder for N600-24.2/538/566 steam turbines, causes leading to above problems are analyzed, while their impacts on efficiency of relevant steam turbines studied, for which corresponding countermeasures are put forward.
  • Operation & Retrofit
    Analysis on Hydrogen-side Oil-way Balance Fault of a Generator Double-loop Sealing Oil System
    Tian Yang
    2013, 27(5): 358-360.
    Abstract ( )   Knowledge map   Save
    An introduction is being presented to the balance fault occurring in the hydrogen-side oil path of a double-loop sealing oil system. The problem is found to be caused by blocking in balance valve due to poor oil quality, and the too large differential expansion of turbine low-pressure cylinder may also cause unbalance of the valve. Corresponding countermeasures are put forward, such as replacing the old balance valve with new one and changing the worn out pad, etc.
    • Product Design
  • Product Design
    Improvement on Design of Electronic Weighing Type Coal Feeders
    Zhang Baoqing, Cui Lüxing
    2013, 27(5): 361-365.
    Abstract ( )   Knowledge map   Save
    To satisfy the high requirement on analog signal sampling by coal feeder control system, an improved design has been performed for the system using the high-precision differential analog output instrumentation amplifier AD8222 and high-precision differential analog input A/D converter AD7799, with focus on the system hardware interface and the program software design process. Practices indicate that the newly designed system can significantly improve the sampling precision and achieve high measuring accuracy required by the coal feeder control system.
    • nvironmental Technology & Equipment
  • nvironmental Technology & Equipment
    Formation, Harms and Control Technology of SO3 from Coal-fired Power Plants
    Jiang Haitao, Cai Xingfei, Fu Yuling, Jia Minghua, Zhang Yubin
    2013, 27(5): 366-368.
    Abstract ( )   Knowledge map   Save
    Aiming at the problems that the removal efficiency of SO3 by pollutant control technologies widely used in current coal-fired power plants is limited, the formation mechanism and harms of SO3 are analyzed, and it is pointed out that SO3 of high concentration will corrode equipment and cause problems as visible smoke plume. Five methods for control and removal of SO3 are proposed for selection if required.
    • Cleaning Energy
  • Cleaning Energy
    A New Maintenance Crane for Wind Turbines
    Shen Xin
    2013, 27(5): 369-384.
    Abstract ( )   Knowledge map   Save
    An analysis was performed to the structures of maintenance cranes in the engine room of wind turbines, based on which, one of the crane was restructured using innovative thinking. Two new maintenance cranes were designed and compared in terms of structure.