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    Testing & Research
  • Testing & Research
    Study and Preliminary Design of Double-reheat Ultra-supercritical Boiler
    Wang Fengjun, Huang Ying, Liu Hengyu, Luan Shijian
    2013, 27(2): 73-77.
    Abstract ( )   Knowledge map   Save
    Compared with traditional single-reheat unit, the thermal efficiency of double-reheat unit is further improved and the wetness requirement of exhaust steam in its low-pressure cylinder can be satisfied. To develop high-efficient and environment-friendly double-reheat ultra-supercritical boiler with proprietary intellectual property rights is an important development direction in our power industry. The necessity of developing large-capacity ultra-supercritical double-reheat unit is proposed, while corresponding preliminary ideas and solutions for boiler design put forward, which makes an effort for filling the gap of our country in the ultra-supercritical double-reheat power generation unit.
  • Testing & Research
    Study on PLS-based Prediction Model for Mass fraction of Carbon Content in Boiler Fly Ash
    Ge Yanpeng, Cui Ning, Dong Lili, Yang Chen
    2013, 27(2): 78-81.
    Abstract ( )   Knowledge map   Save
    Aiming at the problems such as lagging, large error, and so on of the existing measurement method for mass fraction of carbon content in boiler fly ash, a Partial Least Squares (PLS)-based prediction model was put forward, based on which analysis and testing on the regression effect of the model have been made upon a large amount of operating (sample) data of a power plant. Results show that the method can overcome the multiple correlations among data and is characterized by high prediction speed and calculation accuracy.
  • Testing & Research
    Cavitation Characteristics of Water Ring Vacuum Pump for Double Pressure Condenser and the Countermeasures
    Cheng Dongtao, Wang Huan, Ma Tingshan, Ju Wenping, Xu Pengjiang
    2013, 27(2): 82-86.
    Abstract ( )   Knowledge map   Save
    Through analysis on cavitation characteristics of water ring vacuum pump of double pressure condenser, it is proved that the water ring vacuum pump for low-pressure condenser is easy to have problems of cavitation and insufficient output and therefore increases the pressure of the low-pressure condenser. This is also verified by an actual example, of which the unit economical efficiency is seriously affected. Aiming at how to prevent the cavitation and effectively increase the NPSH (net positive suction head) thereof, multiple optimization measures were elaborated with the purposes of reducing the working liquid temperature and increasing the inlet pressure of the vacuum pump, which has guiding significance to the design and retrofit of the system for working liquid cooling and steam extraction in double pressure condensers.
  • Testing & Research
    Study on Static and Dynamic Analysis Methods for Open Drain Safety Valve Piping
    Zhou Zhaowei
    2013, 27(2): 87-90.
    Abstract ( )   Knowledge map   Save
    The data on the force, stress and displacement of an open drain safety valves piping was obtained by calculating, analyzing and comparing the static and dynamic properties of the safety valve piping under three different methods, namely equivalent static method, response spectrum analysis method and time-history analysis method. Analysis to the calculation results indicates that the accuracy of the result calculated by equivalent static method is greatly affected by the dynamic load factor and it is easy to overlook some vibration modes not in the direction of exciting force, finally resulting in the irrational stress calculation of the whole piping. The response spectrum analysis method is a calculation method mainly based on the already-obtained response spectrum curve, which is much better than the equivalent static method in terms of calculation precision, but inclines to be conservative in the calculation result. The time-history analysis method integrally reflects the whole process of piping vibration by time integration, which has a high calculation precision but huge calculation work.
  • Testing & Research
    Analysis and Testing on Flow Characteristics of an Erosion-resistant Regulating Valve
    Ma Jun, Gao Yiqiu
    2013, 27(2): 91-93.
    Abstract ( )   Knowledge map   Save
    To improve erosion resistance and meet governing characteristics of regulating valves for steam turbine, a suggestion is proposed to adopt segmented design and squirrel-cage multi-stage depressurization structure for the turbine. Flow characteristics of the regulating valve are calculated, while influence of slide valve clearance on the flow characteristics analyzed, based on which the flow characteristic curve is corrected. Through testing on the flow characteristics, main causes leading to the error occurring at small opening of the valve are analyzed. Results show that the calculated data agree well with actual measurements.
  • Testing & Research
    Discussion on Control Oil Supply System of Steam Turbines
    Xie Weiyang
    2013, 27(2): 94-96.
    Abstract ( )   Knowledge map   Save
    Aiming at the configuration of control oil supply system for steam turbines, the influence of oil supply system on operation reliability of the unit was analyzed, with focus on the capacity and configuration of the control oil pump. Analysis results show that it is not necessary to increase the capacity of the oil pump for multi-user oil supply and the capacity of oil pump may be reduced in high-pressure oil supply. Small-capacity pumps are relatively energy-saving and large-capacity pumps are in favor of increasing the unit operation reliability. Moreover, suggestions on optimization of design and control logic are proposed for public control oil supply systems.
    • Computer & Control
  • Computer & Control
    Combustion Optimization of Power Plant Boilers Based on RBF Neural Network Model
    Bao Chunlai, Zhang Jingfei
    2013, 27(2): 97-100.
    Abstract ( )   Knowledge map   Save
    Aiming at the influence of boiler combustion on operational economy of the unit, radial basis function (RBF) neural network was adopted to establish a boiler operation optimization model that takes boiler thermal efficiency and mass concentration of NOx emission as the optimization objectives, based on which the opening degree of both the secondary and burn-off air damper was optimized. Results show that the system can simultaneously realize NOx emission reduction and boiler efficiency improvement, which is able to accurately reflect the dynamic characteristics of boiler unit.
  • Computer & Control
    Study on Key Problem of Advanced Control Algorithm in Thermal Control
    Hao Yongsheng, Yu Chong, Wu Bo
    2013, 27(2): 101-104.
    Abstract ( )   Knowledge map   Save
    As the control object in the thermal process is characterized in large lag, time varying and nonlinearity, it is difficult to achieve satisfactory control effect by using the conventional control strategy in the distributed control system. Taking predictive control as an example, some key problems such as system platform selection, main control algorithm and system trace switching, are introduced and analyzed. The solutions have been studied in combination with relevant researches and applications and some conclusions have been drawn, providing ideas for engineering implementation of advanced control systems.
  • Computer & Control
    Performance Analysis and Improvement of Over-speed Protection Device of SPPA-T3000 System
    Lin Sheng
    2013, 27(2): 105-108.
    Abstract ( )   Knowledge map   Save
    A description is being presented to the malfunction process of an over-speed protection device during the use of SPPA-T3000 system in power plant, while an analysis made to the performance and operating mechanism of the protection device. It is pointed out that malfunction may occur during the use of the protection device, which has been proved by simulation tests. However the malfunction may be avoided by effective retrofit, which helps to raise the operational reliability of the protection device.
    • Operation & Retrofit
  • Operation & Retrofit
    Cause Analysis of Boiler Burner Burnout in a 1 000 MW Ultra-supercritical Unit and the Countermeasures
    Feng Zhiyu
    2013, 27(2): 109-112.
    Abstract ( )   Knowledge map   Save
    An introduction is being presented to the burnout condition of a 1 000 MW ultra-supercritical boiler burner in Beijiang Power Plant, together with an analysis performed to the burnout causes, from the aspect of air distribution, ignition distance, inlet coal quality variation, burner structure and material, etc., based on which preventive measures are put forward according to actual conditions. Furthermore, optimization values for the opening of air dampers around the burner at various layers are provided to serve as a reference for combustion adjustment and operation optimization of same type boilers.
  • Operation & Retrofit
    Cause Analysis and Treatment of Oil Damper Damage in a 1 000 MW Steam Turbine
    Sun Lei, Qu Haiying
    2013, 27(2): 113-115.
    Abstract ( )   Knowledge map   Save
    By analyzing the reasons leading to oil damper damage of the high and intermediate pressure bearing box for a 1 000 MW steam turbine and the bearing vibration problem, above abnormal phenomenon is found to be caused by carbon deposition on the oil damper, to which corresponding countermeasures are proposed, such as adopting new energy-saving thermal insulation material and changing air dampers No.1 to No.4 into airtight type, etc., so as to fundamentally solve the problems of carbon deposition on the journal and abrasion of the oil damper.
  • Operation & Retrofit
    Feedwater Regulation in Cold Start of a 600 MW Supercritical Unit without Motor-driven Feed Pump
    Yan Dongsheng
    2013, 27(2): 116-118.
    Abstract ( )   Knowledge map   Save
    Aiming at the characteristics of the water supply system for a 600 MW supercritical once-through boiler, it is proposed to adopt the mode of feeding water by turbine-driven feed pump in the whole process of cold start of the unit. Problems are analyzed to which attention must be paid in different stages, such as in the period of cold washing, ignition, hot washing, turbine rotation-impulsing, medium-speed warming, valve switching, synchronization and initial-load warm-up, steam supply switching for feed pump, dry-wet state transfer and combination of turbine-driven feed pump, etc. Economical benefits of the water feeding mode are evaluated simultaneously.
  • Operation & Retrofit
    Development and Application of New Drawable Air Heaters 
    An Desheng, Fan Xinglong, Zhang Weibao, Guo Chunyuan, Li Jianjun, Li Bokui, Yin Guoqiang
    2013, 27(2): 119-121.
    Abstract ( )   Knowledge map   Save
    An introduction is being presented to the necessity of developing a new drawable air heater, together with a description to its structural principle and successful application example. Measurement results with drawable air heater in the application example prove it to have good effects in reducing ventilation resistance and coal consumption. The investment can generally be recovered within one year, therefore, it is worth being popularized in thermal power plants.
    • Environmental Technology & Equipment
  • Environmental Technology & Equipment
    Control System Design of Long Retractable Soot Blowerfor FGD Gas-Gas Heater
    Han Chunhui
    2013, 27(2): 122-126.
    Abstract ( )   Knowledge map   Save
    Soot blower is very important to the gas-gas heater (GGH) for coal-fired boiler flue gas desulfurization (FGD). An introduction is being presented to major features and design ideas of the programmed control system, which takes S7-200PLC as the logic controller and OP177B operation screen as the monitoring interface. Meanwhile, the design of software and software for the control system is also described. 
  • Environmental Technology & Equipment
    Experimental Study on Desulfuration Optimization of Large-scale CFB Boilers
    Ren Jie, Li Shiming, Ren Fei
    2013, 27(2): 127-128.
    Abstract ( )   Knowledge map   Save
    Aiming at the limestone desulfuration efficiency of large-scale circulating fluidized bed (CFB) boiler, orthogonal method was used to carry out the desulfurization test based on the theory of statistics, so as to obtain optimal conditions for the desulfurization. Results show that rational control of operating parameters of CFB boiler can improve the desulfuration efficiency and reduce the pollutant discharge.
  • Environmental Technology & Equipment
    Research and Development of SNCR Denitrification Technology for CFB Boilers
    Zhang Dinghai, Zhang Fang, Wu Jipin, Mao Yu, Zhou Qi, Ye Mao
    2013, 27(2): 129-132.
    Abstract ( )   Knowledge map   Save
    By applying the mode of staging air and stratified combustion, the NOx emission of a CFB (circulating fluidized bed) boiler can be controlled at about 200 mg/m3 by itself, and if SNCR (selective non-catalytic reduction) denitrification technology is applied with simple ammonia or urea injection system, the emission level can be further reduced to 100 mg/m3 or even below. A SNCR numerical simulation has been performed to the CFB boiler, while studies carried out to the SNCR technology on a hot 3 MW CFB test rig. Results show that by adopting SNCR technology for CFB boiler, the denitrification efficiency can reach 60%. Expected objectives have been achieved for an actual engineering project with the application of this technology.
  • Environmental Technology & Equipment
    Regeneration Practice of Catalyst in SCR Denitration of Boiler Flue Gas
    Li Shutian
    2013, 27(2): 133-135.
    Abstract ( )   Knowledge map   Save
    Aiming at the loss of catalyst in the SCR denitration of boiler flue gas, small and pilot-scale tests on catalyst regeneration were performed, during which inactivated catalyst was tested to study the reason of the inactivation. An introduction is being presented to both the regeneration scheme for inactivated catalyst and the activity indexes of catalyst before and after regeneration, together with a detail description to the pilot-scale test and engineering application of catalyst regeneration. Results show that the regeneration practice is successful and the activity of inactivated catalyst can be recovered effectively after regeneration. Moreover, the denitration efficiency has been improved to some extent.
  • Environmental Technology & Equipment
    Influence of Upper Sealing Condition of Circular Cooler on Waste Heat Power Generation
    Zhou Yongping, Liu Haiming, Huang Hua, Yi Qing, Yao Qiong, Pan Zengsheng, He Shimin
    2013, 27(2): 136-138.
    Abstract ( )   Knowledge map   Save
    Aiming at the waste heat utilization of circular cooler in steel works, researches have been made in combination with a 415 m2 circular cooler, in which air leakage exists in the gap between its gas hood and trolley top surface. Calculation of power generation has been performed before and after sealing retrofit to the gap. Results show that the power generation may be increased by 481 kW after retrofit, proving the sealing retrofit to be necessary and effective for the upper part of the circular cooler.
    • Cleaning Energy
  • Cleaning Energy
    An Optimal Wind Energy Capture Strategy
    Cao Shuqiang, Du Shuwang
    2013, 27(2): 139-141.
    Abstract ( )   Knowledge map   Save
    A method for achieving optimal wind energy capture of wind turbine is being presented by searching the optimal wind energy utilization factor Cp through hill-climbing method based on control of rotating speed and torque sensor. The system conducts tuning to the rotating speed-torque sensor according to long-term data statistics to reduce the hill-climbing time and allow the unit to work at the optimal Cp value in most of the time so as to increase the power generation of wind turbine units.
    • Research on Standard
  • Research on Standard
    Requirements on Qualification Test of AP1000 Medium-voltage Electrical Penetration Assemblies
    Yu Gaowei, Hu Ziying, Wu Keke, Zhu Xiaoping
    2013, 27(2): 142-144.
    Abstract ( )   Knowledge map   Save
    Based on relevant standards and technical data, the functions of electrical penetration assemblies for AP/CAP series third-generation nuclear power station have been introduced. It is analyzed how to consider both the IEEE standard and the GB standard in the design and testing during the localization of above penetration assemblies. Emphases are laid on the introduction of the standard requirements and acceptance criteria related to the electrical testing of medium-voltage electrical penetration assemblies.