首页 | 本学科首页   官方微博 | 高级检索  
检索     
共有20条相似文献,以下是第1-20项 搜索用时 125 毫秒

1.  Development and Application of Maintenance Template in Pressurized Water Reactor Nuclear Power Plant  
   张圣  陈宇  曹智鹏  莫春铌《东华大学学报(英文版)》,2015年第32卷第1期
   Good practices of maintenance optimization in nuclear power field need to be effectively consolidated and inherited,and maintenance optimization can provide technology support to create a long-term reliable and economic operation for nuclear power plants( NPPs) especially for a large number of nuclear powers under construction. Based on the development and application of maintenance template in developed countries,and combining with reliability-centered maintenance( RCM) analysis results and maintenance experience data over the past ten years in domestic NPPs, the development process of maintenance template was presented for Chinese pressurized water reactor( PWR) NPP,and the application of maintenance template to maintenance program development and maintenance optimization combined with cases were demonstrated. A shortcut was provided for improving the efficiency of maintenance optimization in domestic PWR NPP,and help to realize a safe,reliable,and economic operation for domestic NPPs.    

2.  Safety characteristics of Li-ion batteries evaluated by in situ measurement techniques  
   YANG Li WANG Baofeng QIU Yali《科学通报(英文版)》,2005年第50卷第22期
   Li-ion batteries hold an important place in the field of high power batteries because of their high open circuit voltage and associated high energy density. However, the safety is less satisfactory; therefore, the study of the factors that affect the safety of Li-ion batteries has much meaning to the safety design. In this paper, a set of apparatus was developed for in situ measurements, and several commercial materials including electrolyte, separator and electrode materials for Li-ion batteries were investigated by the in situ method. The results showed: 1) The electrolyte vapor pressure is influenced significantly by the component with low boiling point and increases rapidly with the increasing of temperature; 2) the shutdown of separator occurs at around 135℃ and the impedance increases approximately by two orders of magnitude; 3) carbon anode materials affect the most the volume changes of the cell, and the change for a graphite anode is much greater than that of a glassy carbon anode.    

3.  Technical modifications & management innovations in exporting nuclear reactor projects  
   Mao Xiaoming  Qin Xijiu  Ding Hu  Xue Zhaoqun  Wen Shengjun《中国工程科学》,2009年第7卷第4期
   As a main channel for the foreign economic cooperation of China nuclear industry, China Zhongyuan Engineering Corporation (CZEC) has been constantly engaged in technical modifications and management innovations in its exporting nuclear reactor projects. In the implementation of heavy water research reactor contract in Algeria, CZEC had established a complete and adequate design standards system in compliance with the international standards, and made significant modifications to the reference reactor in the aspects of reactor power and reactor safety, solved quite some technical issues which'affected the reactor technical performance. The modifications and improvements enabled the tech- nical parameters, safety features, reactor multipurpose application to attain to the advanced level in the world. In the 300 MWe PWR NPPs in Pakistan, safety features had been updated in line with upgrading regulatory requisites. The design philosophy and technology application demonstrated CZEC' s creation and innovation on basis of constant safety enhancement of nuclear power projects. Efforts had also been made by CZEC in promoting China made equipment items and components exportation.    

4.  Study on the effect of highway construction on photosynthetic rate of roadsides plant in Longitudinal Range-Gorge Region  
   LIU Jie CUI Baoshan DONG Shikui ZHU Jianjun YAO Weike《中国科学通报(英文版)》,2006年第51卷第B11期
   A case study was conducted on Dabao (from Dali city to Baoshan city) and Sixiao (from Simao city to Xiaomengyang town) highways in Longitudinal Range-Gorge Region to investigate the effect of highway construction on photosynthetic rate of roadsides plants. The dominant species in the plant communities were selected to measure the variation of their photosynthetic rate with the distance to the highway, so as to analyze the effect of highway construction on photosynthesis and growth of roadside plants by using mathematic methods including contrast analysis, regress analysis and so on. Results indicate: (1) Highway construction reduced the plant photosynthetic rate of the arbor and crop, and improved the plant photosynthetic rate of the shrub and herbage; (2) highway construction directly affected the plant photosynthetic rate through changing the structure of plant community and living state of plant, and indirectly affected the plant photosynthetic rate through changing its environmental factors; (3) the location and topography of road are also important factors affecting plant photosynthetic rate on roadsides, the influencing incidence and intensity on plant photosynthetic rate under different topographies caused by the two selected highways were obviously different.    

5.  Nuclear Power Plant Life Extension - How Aging Affects Performance of Containments Other Structures  
   Robert A Dameron  Sun Junling《中国工程科学》,2013年第11卷第3期
   This paper focuses on how aging can affect performance of safety-related structures in nuclear power plants (NPPs). Knowledge and assessment of impacts of aging on structures is essential to Plant Life Extension analysis, especially performance to severe loadings such as loss-of-coolant-accidents or major seismic events. Plant life extension issues are of keen interest in countries (like the United States) which have a large, aging fleet of NPPs. Seismic issues are of heightened interest to the worldwide nuclear community in the wake of the 2011 Tohoku Earthquake and Tsunami. This paper addresses the overlap and relationship of structure aging to severe loading performance, with particular emphasis on containment structures.    

6.  The Influencing Factors of sCER Price Dynamics Under the Clean Development Mechanism: Theory and Econometric Analysis  
   Chen Zhang  Yaqi Wu  Yu Yang《系统科学与复杂性》,2018年第31卷第5期
   In order to explore the factors and their complex mechanism affecting the price dynamics under the clean development mechanism(CDM), this article employs the secondary Certified Emission Reduction(sCER) carbon price as the study object, and analyzes its influencing factors from aspects of the international carbon-reduction policies, macroeconomic fluctuations, energy and similar carbon products prices. The innovation of this paper lies in: Introducing necessary factor(the developing countries pricing power) and the application of several international representative indicators to underline the "world" nature of CDM; utilizing different econometric models to obtain noteworthy and more robust results. The authors test the theoretical findings with multiple stationary time series from the launch of CDM to present(2008–2016). The results reveal that s CER price fluctuation shows the characteristic of asymmetry and substantial persistence. There is a strong statistically significant relationship between macroeconomic conditions, coal and oil prices, with the price of s CER. The authors discover that the pricing power of developing countries indeed has a clear but small impact on the s CER price changes, whereas the price elasticity of supply under CDM is so weak. The interaction between EU emission allowances(EUAs) and s CER presents a shift from dependency to substitution.    

7.  Techno-economic evaluation of oxy-combustion coal-fired power plants  
   XIONG Jie  ZHAO HaiBo & ZHENG ChuGuang State Key Laboratory of Coal Combustion  Huazhong University of Science    Technology  Wuhan   China《科学通报(英文版)》,2011年第56卷第31期
   Increasing attention is being paid to the oxycombustion technique of coal-fired power plants because CO 2 produced from fossil fuel combustion can be captured and sequestrated by it. However, there are many questions about the economic properties of the oxy-combustion technique. In this paper, a detailed techno-economic evaluation study was performed on three typical power plants (2 × 300 MW subcritical, 2 × 600 MW supercritical, 2 × 1000 MW ultra supercritical), as conventional air fired and oxycombustion options in China, by utilizing the authoritative data published in 2010 for the design of coal-fired power plants. Techno-economic evaluation models were set up and costs of electricity generation, CO 2 avoidance costs as well as CO 2 capture costs, were calculated. Moreover, the effects of CO 2 tax and CO 2 sale price on the economic characteristics of oxycombustion power plants were also considered. Finally, a sensitivity analysis for parameters such as coal sample, coal price, air separation unit price, flue gas treatment unit price, CO 2 capture efficiency, as well as the air excess factor was conducted. The results revealed that: (1) because the oxy-combustion technique has advantages in thermal efficiency, desulfurization efficiency and denitration efficiency, oxy-combustion power plants will reach the economic properties of conventional air fired power plants if, (a) the CO 2 emission is taxed and the high purity CO 2 product can be sold, or (b) there are some policy preferences in financing and coal price for oxy-combustion power plants, or (c) the power consumption and cost of air separation units and flue gas treatment units can be reduced; (2) from subcritical plants to supercritical and finally ultra-supercritical plants, the economics are improving, regardless of whether they are conventional air fired power plants or oxy-combustion power plants.    

8.  Re-engineering transformer maintenance processes to improve customized service delivery  被引次数:1
   Amy J.C.TRAPPEY  Charles V.TRAPPEY《系统科学与系统工程学报(英文版)》,2011年第20卷第3期
   The outage of a transformer in a power generation system will generally result in a shutdown of the entire system.Consequentially,large amounts of revenue are lost to the plant owner with a substantial negative impact on the civil community and industrial customers.This paper analyzes the current maintenance practices(i.e.,an as-is process model) of a transformer manufacturing company,which provides maintenance services to power generation plants and reports the major weaknesses in current business pract...    

9.  Numerical investigation on the cluster effect of an array of axial flow fans for air-cooled condensers in a power plant  
   LiJun Yang   XiaoZe Du   Hui Zhang and YongPing Yang《科学通报(英文版)》,2011年第56卷第21期
   The aerodynamic behavior of tens of axial flow fans incorporated with air-cooled condensers in a power plant is different from that of an individual fan.Investigation of the aerodynamic characteristics of axial flow fan array benefits its design optimization and running regulation.Based on a representative 2600 MW direct-dry cooling power plant,the flow rate of each fan and the overall flow rate of the fan array are obtained in the absence of ambient wind and at various wind speeds and directions,using CFD simulation.The cluster factor of each fan and the average cluster factor of the fan array are calculated and analyzed.Results show that the cluster factors are different from each other and that the cluster effect with ambient wind is significantly different from the cluster effect with no wind.The fan at the periphery of the array or upwind of the ambient wind generally has a small cluster factor.The average cluster factor of the array decreases with the increasing wind speeds and also varies widely with wind direction.The cluster effect of the axial flow fan array can be applied to optimize the design and operation of air-cooled condensers in a power plant.    

10.  The Module HTGR Development in China  
   Wu Zongxin《中国工程科学》,2007年第5卷第4期
   High Temperature Gas-cooled Reactors are recognized as a representative advanced nuclear system for the future owing to the excellent safety performance, high efficiency, multipurpose uses and hydrogen production. These type reactors are characterized by ceramic coated particle fuel, inert helium as coolant, and graphite used as moderator and reflector in core, which makes the outlet temperature of coolant reaching 950℃ even more. Under the National High Technology Program, the HTR10 project has been successfully implemented and achieved full power operation in connection with the grid in January of 2003. HTR10, which is the first module HTR with inherent safety feature around world, has carried out safety demonstration tests simulating the severe accident conditions in 2004.Based on the proven technologies and experience feedback during HTR10 design, manufacture, construction and operation, a HTRPM demonstration power plant with 200MWe power capacity sited at Rongcheng of Shandong province has been initiated.    

11.  Three Gorges Project: a project for ecological improvement and  
   Lu Youmei《中国工程科学》,2011年第9卷第3期
   Seeking water and earning their livelihoods is the natural selection of human beings.Like other rivers on the earth,the Yangtze River is the birthplace of human civilization and survival.As an ecosystem,the Yangtze River Basin is evolving under the influences of natural factors and human activities.Because of soil erosion,pollution and human activities,the imbalance of secondary environment is exacerbated and the ecological environment has become more vulnerable,so it is urgent to mitigate and prevent the ecological crisis.The practice has proved that implementation of engineering measures is an effective way to improve the ecological environment.The Three Gorges Project (TGP) has a flood control storage capacity of 22.15 billion m 3,effectively storing the flood water upstream of Yichang,and protects 15 million people and 1.5 million hm 2 farmland.Furthermore,the project can prevent or slow down the sedimentation and shrinkage of the lakes in the middle Yangtze River such as Dongting Lake;with an average annual power generation of about 90 billion kW· h,it can significantly reduce the emissions of harmful gas like CO 2.In general,the construction of TGP is conducive to the ecological and environmental protection in the Yangtze River Basin and China,even the world.    

12.  Project Construction and Important Technical Innovation for Qinshan Phase Ⅲ (PHWR) Nuclear Power Plant  
   Third Qinshan Nuclear Power Co. Lt  CNNC《中国工程科学》,2007年第5卷第4期
   Qinshan Phase Ⅲ (PHWR) Nuclear Power Plant, the first commercial heavy water reactor nuclear power plant in China, was the biggest trade project performed between the governments of China and Canada. As the owner, the Third Qinshan Nuclear Power Company (TQNPC) persisted in independent innovation management during the project construction, commissioning and selfdependent operation, efficiently realizing the three controls of the project, i.e. quality control, schedule control and investment control, and persisted in technical improvement on the basis of digestion and absorption of CANDU6 technology to improve the unit safety and reliability. The project construction practice has helped China’s nuclear power project management to becomeprogrammed, computerized, standardized and internationalized management from the existing basis. After completion of the project, with unit safe and steady operation as the prerequisite, TQNPC performed several technical modifications and innovations to continuously improve the unit performance. In the area of staff development, TQNPC paid much attention to cultivation of corporate culture, strengthed staff training and built up a good circulating mechanism with staff training and project construction promoting each other. Further to “Zero Breakthrough” and a new step forward of locolization successfully realized in Qinshan Nuclear Power Plant and Nuclear Power Qinshan Joint Venture Company, the improvement and developemnt of nuclear power project management level in Qinshan Phase Ⅲ (PHWR) Nuclear Power Plant provided reference for promotion of nuclear power development in China and standardized management of introducing large imported project.    

13.  Trip Generation Model Based on Destination Attractiveness  
   姚丽亚  关宏志  严海《清华大学学报》,2008年第13卷第5期
   Traditional trip generation forecasting methods use unified average trip generation rates to determine trip generation volumes in various traffic zones without considering the individual characteristics of each traffic zone. Therefore, the results can have significant errors. To reduce the forecasting error produced by uniform trip generation rates for different traffic zones, the behavior of each traveler was studied instead of the characteristics of the traffic zone. This paper gives a method for calculating the trip efficiency and the effect of traffic zones combined with a destination selection model based on disaggregate theory for trip generation. Beijing data is used with the trip generation method to predict trip volumes. The results show that the disaggregate model in this paper is more accurate than the traditional method. An analysis of the factors influencing traveler behavior and destination selection shows that the attractiveness of the traffic zone strongly affects the trip generation volume.    

14.  Modeling of Operators’ Workload in a Nuclear Power Plant  
   Dai Licao  Zhang Li  OuYang Jun  Huang Shudong《中国工程科学》,2008年第6卷第1期
   Accidents in a nuclear power plant are coped with by operators in the main control room (MCR). An analysis of the workload of operators in a MCR after the happening of initiating events is helpful to the alleviation of human errors and to the promotion of training efficiency. This paper establishes a framework of how man is located in a man-ma- chine interface of a nuclear power plant (NPP) as well as a simulation of the man-machine scenario in accidents in NPPs, including the simulation of the operators' task and cognitive work and the establishment of task analysis. On the basis of the above, a model of the dynamic changes of the operators' tasks is constructed and a computation of operators' workload is conducted.    

15.  Seismic Hazard Mitigation for Nuclear Power Plants  
   Frieder Seible《中国工程科学》,2013年第11卷第3期
   The seismic safety of nuclear power plan(tNPP)has always been a major consideration in the site selection,design,operation,and more recently recertification of existing installations. In addition to the actual NPP and all their operational and safety related support systems,the storage of spent fuel in temporary or permanent storage facilities also poses a seismic risk. This seismic risk is typically assessed with state-of-the-art modeling and analytical tools that capture everything from the ground rupture or source of the earthquake to the site specific ground shaking,taking geotechnical parameters and soilfoundationstructureinteraction (SFSI) into account to the non-linear structural response of the reactor core,the containment structure,the core cooling system and the emergency cooling system(s),to support systems,piping systems and non-structural components,and finally the performance of spent fuel storage in the probabilistically determined operational basis earthquake (OBE) or the safe shutdown earthquake (SSE) scenario. The best and most meaningful validation and verification of these advanced analytical tools is in the form of full or very large scale experimental testing,designed and conducted in direct support of model and analysis tool calibration. This paper outlines the principles under which such calibration testing should be conducted and illustrates with examples the kind of testing and parameter evaluation required.    

16.  Experimental Study on the Hydrodynamics and Mass TransferCharacteristics of Airlift Loop Reactors(ALR)  
   Tang Lixin  Han Pingfang  Lu Xiaoping《中国工程科学》,2007年第9卷第1期
   The promoting effect of ultrasonic wave on the hydrodynamics and mass transfer characteristics of theairlift loop reactor was studied.The effect of the airlift reactor and ultrasonic wave on the reactor’s gasholdup,liquid circulation velocity,mixing time and overall volumetric mass transfer coefficient respectivelywith and without the presence of ultrasonic wave is empathetically examined and compared.The experiment hasproven that the incorporation of ultrasonic wave has no effect on the gas holdup but has the tendency togradually decrease the liquid circulation velocity and increase the overall volumetric mass transfer coefficient;the effect on the mixing time is relatively complex.At low gas velocity,low powered ultrasonic wave promotesthe radial mixing of fluid;with the increase of ultrasonic power,ultrasonic vibration obstructs the radial mixingof fluid.Therefore,there exists an optimal ultrasonic power.Moreover,the effect of ultrasonic wave on themixing time gradually decreases with the increase of the superficial gas velocity.Correlations were alsoproposed for the hydrodynamics and mass transfer characteristics of the reactor.    

17.  Molecular hydrogen isotope analysis of living and fossilplants—Metasequoia as an example  
   Hong Yang  Qin Leng《自然科学进展(英文版)》,2009年第19卷第8期
   Molecular hydrogen isotope analysis preformed on modern and fossil plants has made a significant impact on diverse research fields in biology and geology. Using living and fossil Metasequoia as an example, we review the technology of online GC-IRMS that made the molecular analysis of hydrogen isotope possible and discuss critical issues concerning with the studies of molecular dD and its applications. The apparent hydrogen fractionation factors between lipid molecules and source water (ewater–lipid) vary across plant taxonomy and differ among biomolecules and are affected by multiple environmental factors in which precipitation dD values exercise the first order of control. Eco-physiological factors and environmental parameters are also known to influence dD in plants. Molecular hydrogen isotope analysis of chemically stable lipid molecules, such as n-alkanes, finds a wide range of applications in detecting source sediments, reconstruction of paleoclimatic parameters, inference of air-mass trajectory, as well as in petroleum industry and environmental studies.    

18.  SCWR for Future LargeScale Nuclear Power Generation  
   Cheng Xu《中国工程科学》,2007年第5卷第4期
   The ambitious nuclear power program motivates the Chinese nuclear community to develop advanced reactor concepts of generation IV, in order to ensure the longterm, stable and sustainable development of nuclear power. The supercritical watercooled reactor (SCWR) has favorable features in economics, sustainability and technology availability. It is the logical extension of the existing PWR technology and has very promising perspectives in largescale power generation in China. This paper describes the main features of SCWR. New designs of SCWR core structure and fuel assemblies are proposed. Preliminary analysis using a coupled neutronphysics/thermalhydraulics method is carried out and shows a good feasibility of the new design proposal.    

19.  An Analysis of the Factors Impacting Employee's Specific Investment  
   吴爱华  葛文雷《东华大学学报(英文版)》,2008年第25卷第1期
   The amount of specific investment from employees is limited, and the reasons of the under-investment from employees are analyzed in this paper. Based on the relationship of the specific investment and the employee demission, an empirical study has been conducted focusing on the factors influencing the employee turnover and the specific investment. A theoretical model of the factors influencing employee's specific investment is given.    

20.  Primary investisation of the pollution status of polycyclic aromatic hydrocarbons (PAHs) in water and soil of Xuanwei and Fuyuan,Yunnan Province,China  被引次数:2
   LU JunGang  XU RenJi  ZHANG QingHua  LIU JiYan  LIAO ChunYang  WEI FuSheng《科学通报(英文版)》,2009年第54卷第19期
   Lung cancer incidence in Xuanwei and Fuyuan is extremely high. The air pollution, especially indoor airborne PAHs generated by burning smoky coals, has been considered as the most probable reason. The air pollution may affect drinking water and soil through dry and wet deposition. In this study, the concentrations of PAHs in water and soil samples from Xuanwei and Fuyuan were monitored to investigate the influence of atmospheric PAHs pollution on water and soil. No obvious PAHs pollution in water was found in these two areas, indicating that airborne PAHs have no apparent effect on the drinking water (well water). The smoky coal combustion from household and industry, such as the activities related to power plants, coking plants and chemical industries, is responsible for the soil PAHs pollution in these two areas. The soil pollution might be the reemission source and would pose long-term threat to the local environment and health of residents.    

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号