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Measures against the adverse impact of natural wind on air-cooled condensers in power plant

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Science china(Technological Sciences) 2010年第5期53卷 1320-1327页

作者： YANG LiJun,DU XiaoZe & YANG YongPing Key Laboratory of Condition Monitoring and Control for Power Plant Equipment of ministry of education of china,North china Electric Power University,Beijing 102206,china 1. Key Laboratory of Condition Monitoring and Control for Power Plant Equipment of ministry of education of china North China Electric Power University Beijing 102206 China

The natural wind plays disadvantageous roles in the operation of air-cooled steam condensers in power *** is of use to take various measures against the adverse effect of wind for the performance improvement of air-cooled *** on representative 2×600 MW direct air-cooled power plant,three ways that can arrange and optimize the flow field of cooling air thus enhance the heat transfer of air-cooled condensers were *** physical and mathematical models of air-cooled condensers with various flow leading measures were presented and the flow and temperature fields of cooling air were obtained by CFD *** back pressures of turbine were calculated for different measures on the basis of the heat transfer model of air-cooled *** results show that the performance of air-cooled condensers is improved thus the back pressure of turbine is lowered to some extent by taking measures against the adverse impact of natural wind.

关键词： air-cooled condenser wind speed and direction flow and heat transfer back pressure power plant

RAPID EXACT CONTROLLABILITY OFTHE SEMILINEAR WAVE EQUATION

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Chinese Annals of Mathematics,Series B 1999年第3期20卷 377-384页

作者： ZHANG Xu(Institute of Mathematics, Fudan University, Shanghai 200433, china.)(Project supported by the Science Foundation of the ministry of education of china and the Youth Science Foundation of Shanghai’s Universities.) Fudan Univ Inst Math Shanghai 200433 Peoples R China

In this paper the semilinear wave equation with homogeneous Dirichlet boundary condition having a locally distributed controller is considered, and the rapid exact controllability of this system is obtained by changing the shape and/or the location of the controller under proper conditions. For this purpose, the author derives an (rapid) observability inequality for wave equations with linear time-variant potential by means of the energy estimate. The main difference of the method from the previous ones is that any unique continuation property of the corresponding linear time-variant wave equations is not needed.

关键词： Rapid exact controllability Semilinear wave equation Changing controller Energy estimate

Determination of Lateral Extension of Hydrocarbon Concentration Sealing Caprocks by AVO Analysis

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Petroleum Science 2007年第4期4卷 17-22页

作者： Li Weilian Key Laboratory for Hydrocarbon Accumulation Mechanism Ministry of Education China University of Petroleum Beijing 102249 China

The caprock is one of the key factors for a reservoir, especially for a gas reservoir. Whether the caprocks can block off the gas is of significance for the accumulation and preservation of the gas reservoir. In this paper, we use the Amplitude versus offset （AVO） seismic technique to determine the lateral extension of the hydrocarbon concentration sealing caprocks. The essence of this technique is to detect the variations of the reservoir bed physical properties by monitoring the variations of the reflection coefficient of seismic waves upon the interfaces between different lithologies. Generally it is used to indicate hydrocarbon directly. For the hydrocarbon concentration sealing caprocks, the change of hydrocarbon concentration may cause the change of physical properties of the caprocks. Therefore it is possible to evaluate the hydrocarbon concentration sealing ability of the caprocks by AVO. This paper presents a case study using AVO to determine the lateral extension of the hydrocarbon concentration sealing caprocks. The result shows that this method is helpful for the exploration of the region.

关键词： AVO caprock hydrocarbon concentration sealing gas diffusion loss

Progress in researching into the transition of the Mesozoic tectonic systems in southeast china

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Progress in Natural Science:Materials International 2006年第6期16卷 563-572页

作者： YU Xinqi, WU Ganguo, ZHANG Da, ZHANG Xiangxin, DI Yongjun, ZANG Wenshuan, WANG Qunfeng and HUANG Huojian (State Key Laboratory of Geological Processes and Mineral Resources, china University of Geosciences, Beijing 100083, china Key Laboratory of Lithosphere Tectonics and Lithoprobing Technology of ministry of education, china University of Geosciences, Beijing 100083, china) [a] State key Laboratory of Geological Processes and Mineral Resources Chine University of Geosciences Beijing China [b] Key Laboratory of Lithosphere Tectonics and Lithoprobing Technology of ministry of education China University of Geosciences Beijing China

This paper presents the latest progress made on the research of Mesozoic tectonic system transition from the E-W paleo-Tethyan tectonic domain into NE-NNE western Pacific domain in southeast china. Tectonism of the west Pacific domain began at middle Jurassic (J2) and formed a set of NE-trending structures, non-coaxially overprinting on E-trending tectonic belts which may be early and coevally produced by the paleo-Tethyan domain. Thus began the tectonic domain transition from the E-trending paleo-Tethyan to the NE-trending Pacific and fully finished at the early Cretaceous. The eastern Nanling area was a junction zone of the transition at middle Jurassic (J2),and ever since the junction zone might obliquely migrate to the coastal region, where is the east part of this study area. To the north of the Nanling area, the Ganjiang Fault Zone was the boundary between two tectonic domains. Corresponding to the transition of tectonic system, the geodynamics of SE china changed from a compressional system to an extensional system, which continued until the end of Mesozoic-Tertiary.

关键词： transition of tectonic system non-coaxial overprint obliquely migrate Mesozoic paleo-Tethyan tectonic domain west Pacific tectonic domain southeast china.

Research advances in the Mesozoic tectonic regimes during the formation of Jiaodong ore cluster area

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Progress in Natural Science:Materials International 2006年第8期16卷 777-784页

作者： DENG Jun, YANG Liqiang, GE Liangsheng, WANG Qingfei, ZHANG Jing, GAO Bangfei, ZHOU Yinghua and JIANG Shaoqing (State Key Laboratory of Geological Processes and Mineral Resources, china University of Geosciences, Beijing 100083, china Key Laboratory of Lithosphere Tectonics and Lithoprobing Technology of ministry of education, china University of Geosciences, Beijing 100083, china) [a]State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Beijing China [b]Key Laboratory of Lithosphere Tectonics and Lithoprobing Technology of ministry of education China University of Geosciences Beijing China

Based on research advances of the tectonic regime in Jiaodong ore cluster area and the related tectonic regime transformation in Mesozoic era in the eastern region of North china, in this paper, we first summarize some key problems required to be studied further on. Then we suggest an approach to dealing with these problems. It is known that the gold deposits in Jiaodong ore cluster area, which are of different mineralization styles, spatial distributions and geological settings, might be as a result from one or more geologic events in Mesozoic. Till now, this kind of research on the temporal evolution and spatial migration sequence, especially on the geodynamic mechanism of the above events, is far from sufficient. Moreover, quantitatively describing the action mode and the temporal-spatial framework of tectonic dynamic regimes and formulating the relative contribution of every tectonic dynamic regime for the metallogensis are still challenges to the geologists studying on the formation of Jiaodong ore cluster area. According to the interpretation of the regional tectonic analysis, the structural dynamics, the observation and the exploration of the mineralization network, we propose a geological-physical-chemical model with some constraints originated from the comprehensive analysis. We then use this model to simulate the coupled processes of the structural deformation, thermal transport, fluid flow and the chemical reaction. The obtained results indicate that the model is efficient in further analyzing the temporal-spatial evolutional trail of the tectonic regime in Jiaodong ore cluster area and in further understanding the nature of the mass metallogensis.

关键词： tectonic regime Mesozoic era Jiaodong ore cluster area genesis metallogenic system.

Research on common issues for relationship between mechanism degree of freedom,driving link and executive link

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Science china(Technological Sciences) 2009年第4期52卷 966-974页

作者： WANG AiLun College of Mechanical & Electrical Engineering, Central South University, Changsha 410083, china Key Laboratory of Modern Complex Equipment Design and Extreme Manufacturing, ministry of education, Changsha 410083, china 1. College of Mechanical & Electrical Engineering Central South University Changsha 410083 China 2. Key Laboratory of Modern Complex Equipment Design and Extreme Manufacturing Ministry of Education Changsha 410083 China

During engineering practice and theoretical research, the mechanism degree of freedom is sometimes unequal to the number of the driving link, which is unable to be explained according to the classic theory of the mechanism degree of freedom. To solve this problem, the duality description for operating laws of mechanism is introduced based on the concepts of duality. The Junction-Structure Equation is established for the port descriptions of general ideal mechanism and the functional description for the mechanism degree of freedom is described by utilization of bond graph theory. The force-transfer de- gree of freedom, i.e. the antithesis concept of movement-transfer degree of freedom, is introduced and defined based on the analysis of energy transfer as well as the analysis of signal causality. By utiliza- tion of structural description, functional description and duality description for the equation of degree of freedom, the relationship between the movement-transfer degree of freedom and force-transfer de- gree of freedom is further explored and analyzed. Thus, the relationship between the mechanism de- gree of freedom upon the driving link and the executive link is described generally. Finally, some typical relationships between the mechanism degree of freedom, the driving link and the executive link are analyzed.

关键词： duality bond graph Junction-Structure Equation driving link executive link degree of freedom

Metallogenic epoch and genesis of the gold deposits in Jiaodong Peninsula, Eastern china: a regional review

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Progress in Natural Science:Materials International 2007年第2期17卷 138-143页

作者： YANG Liqiang, DENG Jun, GE Liangsheng, WANG Qingfei, ZHANG Jing, GAO Bangfei, JIANG Shaoqing and XU Hao ( State Key Laboratory of Geological Processes and Mineral Resources, china University of Geosciences, Beijing 100083, china Key Laboratory of Lithosphere Tectonics and Lithoprobing Technology of ministry of education, china University of Geosciences, Beijing 100083, china) [a]State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Beijing China [b]Key Laboratory of Lithosphere Tectonics and Lithoprobing Technology of ministry of education China University of Geosciences Beijing China

Gold deposits are characterized by multi-sources, superimposition, large scale and temporal-spatial concentration in Jiaodong Peninsula, Eastern china. In this paper, we review the history and the development of the study on metallogenic chronology and genesis of gold deposits, summarize the main features of superimposed metallogenesis, provide evidence of the Mesozoic complex metallogenic system, and point out some problems for further research of Jiaodong gold deposit cluster from a regional view. Although gold deposits are different in genetic types, ore-forming materials and geological settings, our research indicates that the accumulation and emplacement of the ore-forming materials are temporally-spatially concentrated on a large scale, and the main metallogenic epoch of Jiaodong gold deposits was concentrated in Mesozoic. Metallogenic chronology and geological-geochemical data indicate that there are two periods of gold mineralizations occurred in 130-110 Ma and 90-80 Ma respectively in Jiaodong ore cluster. The gold deposit cluster results from the superimposition of the polygenetic mineralization, and further study is needed to investigate the formation and evolution of the Mesozoic complex metallogenic system.

关键词： superimposed metallogenic system Mesozoic Jiaodong ore cluster.

The integration of methanogenesis with denitrification and anaerobic ammonium oxidation in an expanded granular sludge bed reactor

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Journal of Environmental Sciences 2003年第3期15卷 423-432页

作者： ZHANG Dai-jun 1,2 (1. Department of Environmental Science, Chongqing University, Campus A, Chongqing 400044, china 2. Key Laboratory for the Southwest china Resources Exploitation and Environmental Disaster Control Engineering, ministry of education, china.) Department of Environmental Science Chongqing University China

The integration of methanogenesis with denitrification and anaerobic ammonium oxidation(ANAMMOX) was studied in an expanded granular sludge bed(EGSB) reactor in this work. Experimental results from the continuous treatment of wastewater with nitrite and ammonium, which lasted for 107 days, demonstrated that wastewater with high nitrite and ammonium could be anaerobically treated in an expanded granular sludge bed reactor. More than 91% to 97% of COD were removed at up to about 3.9 g COD/(L·d) of COD volumetric loading rate. More than 97% to 100% of nitrite was denitrified at up to about 0.8 g NO -_2-N/(L·d), which is 16 times higher than that in a conventional activated sludge system with nitrification/denitrification(0.05 gN/(L·d)). No dissimilatory reduction of nitrite to ammonium occurred in the process. However, maximum of about 40% ammonium was found to be lost. Batch tests of 15 days with sludge from the reactor showed that 100% of nitrite was denitrified completely, and about 3% of ammonium was removed when only ammonium (34.3 mg/L) and nitrite(34.3 mg/L) were added into the sludge suspension medium. Furthermore, about 15% of ammonium amounts were lost with organic COD addition. It suggested that the methanogenesis in the system could enhance ANAMMOX because of intermediate hydrogen produced during methanogenesis.

关键词： methanogenesis denitrification ANAMMOX EGSB reactor

Karst conduit flow and its hydrodynamic characteristics——Houzhai River drainage basin in Fueling,Guizhou,china as an example

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Chinese Science Bulletin 2001年第S1期46卷 45-51页

作者： WANG Lachun & ZHANG YongzhanDepartment, of Urban & Resource Sciences, Nanjing University, Nanjing 210093, china Key Laboratory of Coast & Island Development of ministry of education of china, Nanjing University, Nanjing 210093, china 1. Department of Urban & Resource Sciences Nanjing University 210093 Nanjing China 2. Key Laboratory of Coast & Island Development of ministry of education of china Nanjing University 210093 Nanjing China

Conduit flow is a special geomorphologic and hydrological phenomenon in karst area. Houzhai River drainage basin in Puding, Guizhou Province is a large-scale test field in the main and broad karst area in the southern part of china, where conduit flow is a general reserve and drainage system for groundwater. Based on the great deal of field investigation and indoor research work during the 1970s-1980s, pulse tests were done four times there during 1988-1991 in wet and dry seasons. It shows that water level at each observation site changes from 10 to 1800 mm, with the larger variation in upper stream and at karst windows than in lower reaches and at each exit along subterraneous rivers. The average flow velocity in conduit system is determined within 200-800 m/h, with the less change from flood to dry seasons, and it is higher in principal conduits and in upper stream area. Also, the reliable divided discharge ratio among each hydrological conduit of sunken system has been got. Thus, combined with

关键词： conduit flow karst pulse test Houzhai River.