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    Research & Analysis
  • Research & Analysis
    Application of RBF Neural Network Algorithm in Calculationof Water and Steam Properties
    Yang Yu
    2014, 28(3): 151-153.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The inverse function of fundamental formula of IAPWS-IF97 calculation model can be obtained using RBF neural network algorithm in calculation of water and steam properties, of which the calculation results can completely meet the precision requirement of engineering applications. Results with higher precision can also be obtained through Brent iterative calculation by taking the results of RBF neural network algorithm as the initial point.
  • Research & Analysis
    Discussion on AP1000 Nuclear EquipmentQualification Tests
    Zheng Kaiyun
    2014, 28(3): 154-159.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    An introduction is being presented to the basic process and test sequence for AP1000 nuclear power plant safety-related equipment qualification, together with a discussion on test requirements and related technical issues for some crucial qualification test items, such as thermal aging, radiation exposure, seismic resistance, design-based accident simulation, etc. It is pointed out that new requirements and challenges associated with test facilities, test method standards and practical experience are raised for the AP1000 nuclear equipment qualification.
  • Research & Analysis
    Study on Shafting Vibration Characteristics of Megawatt-classNuclear Power Units with Spring Foundation
    Shen Xiulan, Zhu Wei, Jiang Jun
    2014, 28(3): 160-163.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To study the shafting vibration characteristics of megawatt-class nuclear power half-speed turbine-generator units with spring foundation, analysis and evaluation were conducted to the shafting dynamic response using universal resonance peak speed response sensitivity factor Q, of which the analysis results were compared for units respectively with rigid and flexible foundations. Meanwhile, safety analysis was also carried out on torsional vibration of the unit. Analysis results show that the calculated shafting vibration characteristics of the unit can meet current requirements of relevant design standards.
  • Research & Analysis
    Study on Operation Oxygen Optimization for a 1 913 t/h Boiler
    Yang Bangmin, Hu Yike
    2014, 28(3): 164-168.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To study the thermal efficiency and NOx mass concentration in exhaust gas of a 1 913 t/h boiler, test analysis was made to the effects of operation oxygen quantity on the thermal efficiency and NOx generation of boiler. Results indicate that, under the premise of guaranteeing the safe and economic operation of boiler, the reduction of oxygen volume fraction in exhaust gas can not only improve the thermal efficiency of boiler but also decrease the NOx mass concentration. In addition, an optimized operation curve of oxygen quantity was finally recommended
  • Research & Analysis
    Researches and Practices to Reduce the Exhaust Gas Temperature of Ultra-high Pressure Blast Furnace Gas Boilers
    Tao Hongwei, Yue Hong, Zhang Xinyu, Yu Fei
    2014, 28(3): 169-172.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Based on analysis of the blast furnace gas, the flue gas of a 150 t/h blast furnace gas-fired boiler and the low-temperature corrosion of the air preheater, the feasibility to further reduce the exhaust gas temperature of 400 t/h ultra-high pressure gas boilers was studied on the premise of avoiding low-temperature corrosion. Results show that the split-type heat pipe gas heater can effectively reduce the flue gas temperature of ultra-high pressure gas boilers and can simultaneously avoid the low-temperature corrosion, which is also of great significance for the design and retrofit of low- and medium-pressure gas boilers.
  • Research & Analysis
    Thermal Deviation Analysis for Superheaterin Double-tangential Firing Boiler
    Wei Gang, Feng Zhiyu, Su Dapeng, Liu Wei
    2014, 28(3): 173-177.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    An introduction is being presented to the equipment and system of a 3 102 t/h boiler, together with a description to the thermal deviation existing in its superheater under different conditions of steam temperature, metallic wall temperature of heating surface, and water consumption of attemperator at various stages of superheater. Causes leading to the thermal deviation were analyzed, while retrofit suggestions put forward from such aspects as the combustion mode of boiler, heating surface arrangement of superheater, pipeline arrangement at superheater outlet, and so on. Practices indicate that the total temperature rise deviation of all branches has been reduced from 39.2 K to 14.6 K after retrofit.
  • Research & Analysis
    Comparison between Two Thermal Models for Generator Stator Windings
    Liu Xiujie, Yang Ping, Chen Yan
    2014, 28(3): 178-180.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To effectively monitor the real-time temperature of generator stator windings, structural analysis and comparison were conducted to a stator respectively with the typical Fingerprint model and Puying thermal model. Results indicate that the Fingerprint model is more suitable for on-line temperature monitoring of generator stator windings for its simple calculation, variables convenient for engineering analysis, physically meaningful coefficients and high calculation precision.
  • Research & Analysis
    R&D on Combined Water-Air Cooling Dry Slag Disposal Facility for Pulverized Coal-fired Boilers
    in Xiaotian, Sun Xiaona, Zhang Nailiang, Yin Hualei
    2014, 28(3): 181-185.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    For the purposes of energy and water conservation of boiler slag disposal system, a suggestion of combined water-air cooling dry slag disposal system was put forward for retrofit of the original hydraulic slag disposal boiler. It was further compared with the original hydraulic slag disposal and introduced MAC dry slag disposal technology. Results show that the combined water-air cooling dry slag disposal technology is worth being developed and applied.
  • Research & Analysis
    Effects of Converter Pulse Voltage on Insulation Lifeof Doubly-fed Wind Generators
    Liu Yu
    2014, 28(3): 186-188.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To study the effects of DC repetition pulse voltage of converter on service life of corresponding generator insulation system under conditions of high output frequency of the converter, a simulation test was conducted to the stator of a doubly-fed wind generator. Test results indicate that the insulation life under the effect of a pulse voltage with cut-off frequency of 1 kHz is about 20 times different from that under a 50 Hz AC voltage; the main factor influencing the insulation life is the local discharge; the higher the output frequency of the converter, the shorter the insulation life.
    • Material & Technology
  • Material & Technology
    Nonconformity Causes of Lower Shell Forging A in Mechanical PropertyTests of an AP1000 Nuclear Steam Generator
    Jin He, Dong Zezhong, Tian Hongzhi, Cao Ding
    2014, 28(3): 189-192.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Nonconformity causes of lower shell forging A in mechanical property tests of an AP1000 nuclear steam generator were illustrated in details from such aspects as the chemical compositions of base metal, the cooling speed and wall thickness of the forging at quenching & tempering treatment, etc. A practical and feasible plan for improving the pass rate of the lower shell forging A in mechanical property tests was put forward from following aspects such as the control of Al content, the determination of cooling speed after quenching treatment, and the optimization of wall thickness of the forging at the time of thermal treatment, etc.
    • Operation & Retrofit
  • Operation & Retrofit
    Application of Online High-pressure Water Washing Technologyin Rotary Air Preheaters
    Meng Xiangdong, Jin Rifeng, Dai Dong, Liu Dengjun, Li Zhenbo,
    Xing Xidong, Li Zhiqiang
    2014, 28(3): 193-196.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    An online high-pressure water washing test was carried out for the boiler rotary air preheater in a 600 MW unit with the purpose of reducing the pressure difference before and after the preheater, so as to analyze and solve the problems occurring in application of the high-pressure water washing technology. Results show that the high-pressure water washing can reduce the gas pressure difference before and after the air preheater and the running current of fan respectively by 0.8~1.0 kPa and 110 A, indicating a significant benefit.
  • Operation & Retrofit
    Feasibility Study on Differential Pressure Utilizationof Nature Gas at Inlet of Gas Turbine
    Zhang Yi
    2014, 28(3): 197-199.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    At the inlet of a combined cycle unit, there is a 2.5~3.0 MPa pressure differential of nature gas, to apply this waste heat, a scheme was proposed by using an expander, and a discussion was made to the heating mode of natural gas in the scheme. Analysis results indicate that the way of heating the inlet natural gas of expander by feed water can increase the annual income by 5 406 300 Yuan, and recover the investment in 7.27 years, which therefore has good economic benefit and energy saving significance.
  • Operation & Retrofit
    Retrofit on Oxygenated Treatment for Steam-Water System of Ultra-supercritical Units
    Zhang Juan
    2014, 28(3): 200-202.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To reduce the flow-accelerated corrosion in piping system of a 600 MW ultra-supercritical unit, a retrofit scheme was presented by oxygenated treatment to its steam-water system, including the flow chart of oxygenated treatment covering the feed-water system and high-pressure heater drainage system, as well as the arrangement of oxygen-adding and sampling points. Results show that the flow resistance reduces half a year after retrofit due to complete transformation of original Fe3O4 film into compact Fe2O3 film on surface of relevant economizer tubes, and the deposition of iron oxide on rotor blades of the steam turbine reduces accordingly after the retrofit.
  • Operation & Retrofit
    Retrofit on Economizer of a 130 t/h Boiler
    Zhao Minghua, Chen Zhenfang
    2014, 28(3): 203-207.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To reduce the exhaust gas temperature of a 130 t/h pulverized coal-fired boiler, an analysis was made from such aspects as design, operation, maintenance, and so on, after which retrofit measures were put forward for the heating surface of economizer in the tail duct. The exhaust gas temperature is decreased by 20 K on average after retrofit, effectively guaranteeing the safe and economical operation of the boiler.
  • Operation & Retrofit
    Cause Analysis and Countermeasures for Low Yield of an HP1003 Medium-speed Coal Mill
    Yang Jianfeng, Huang Wei, Lei Lin, Yang Jianping
    2014, 28(3): 208-210.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the situation that the yield of an HP1003 medium-speed coal mill is low, an analysis was made to the factors that affect the yield of coal mill. Three affecting factors were ventilation quantity, grinding capability and drying capability. The yield has been improved and can basically meet the operation requirement after some countermeasures were taken.
  • Operation & Retrofit
    Network Optimization of Auxiliary Control Systemfor Thermal Power Plant
    Chen Yongcheng, Zhong Shangwen
    2014, 28(3): 211-212.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To improve the reliability of auxiliary control system in thermal power units, an analysis was made to problems existing in two 600 MW units of Guangdong Red Bay Power Company Limited, to which optimization measures were put forward, such as changing the network physical topology from redundant ring network into redundant star network, upgrading the core switches, VLAN division and taking other hardware and software optimization measures, by which the network reliability is improved.
  • Operation & Retrofit
    Common Faults of Slag Conveyor in a 1 890 t/hBoiler and the Treatment
    Xu Chun, Zhao Xuefeng, Zhu Zhigui
    2014, 28(3): 213-215.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Classification and cause analysis were conducted to common faults of the scraper slag conveyor in a 1 890 t/h boiler, to which corresponding countermeasures were put forward and applied. Application results indicate that the slag conveyor can now work normally after the improvement on its driving device, chain and chain rolling device.
    • Environmental Technology &Equipment
  • Environmental Technology &Equipment
    Airflow Distribution Design for ESP-FF Hybrid Dust Collectors
    Yao Yuping, Zhao Yongshui, Wang Yong
    2014, 28(3): 216-218.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To solve the problems existing in airflow distribution of an ESP-FF (electrostatic precipitator-fabric filter) hybrid dust collectors, a new airflow distribution is numerically developed, which makes the airflow in ESP area be more uniform and the airflow rising velocity in FF area be slower, and therefore obviously improves the performance of the ESP-FF hybrid dust collector. Application results show that the newly-structured ESP-FF hybrid dust collector can completely meet relevant requirements on dust emission.
  • Environmental Technology &Equipment
    Economic Analysis on Retrofit to a Gas-Gas Heaterin Flue Gas Desulfurization System
    Guo Hongbin, Hou Shulin, Yu Fei
    2014, 28(3): 219-220.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    An analysis was carried out to both the harms caused by gas-gas heater (GGH) scaling in flue gas desulfurization system and the scaling reasons, to which retrofit measures were put forward by changing the original heat-transfer unit into large channel straight corrugated plate type. Application results indicate that the operating resistance of GGH and the operating current of booster fan are decreased; the safety and reliability of the flue gas desulfurization system are improved, and the energy saving effect is significant.
    • Power Plant Equipment Management
  • Power Plant Equipment Management
    Aging Mechanism and Management of I&C Equipment in Nuclear Power Plant
    Bu Jiangtao, Bi Daowei
    2014, 28(3): 221-223.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The influence of aging of instrumentation & control (I&C) equipment on operation safety of the nuclear power plant is analyzed from theory aspect, to which key management essentials are put forward. The aging mechanism is studied for components in the I&C system, including various sensors, electronic components, relays, cables and electrical connectors, etc. Relevant strategies are proposed for execution of the equipment management, with focus on obsolescence of relevant electronic components.