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Chongji Z.,Tsinghua University | Yexiang X.,Tsinghua University | Wei X.,National Research Institute for Rural Electrification | Tao W.,National Research Institute for Rural Electrification | And 3 more authors.
IOP Conference Series: Earth and Environmental Science | Year: 2016

In Pelton turbine, the dispersion of cylindrical jet have a great influence on the energy interaction of jet and buckets. This paper simulated the internal flow of nozzle and the downstream free jet flow at 3 different needle strokes. The nozzle model consists of the elbow pipe and the needle rod which supported by 4 ribs. Homogenous model and SST k-ω model were adopted to simulate the unsteady two-phase jet flow. The development of free flow, including a contraction process followed by an expansion process, was analysed detailed as well as the influence of the nozzle geometry on the jet flow pattern. The increase of nozzle opening results in a more dispersion jet, which means a higher hydraulic loss. Upstream bend and ribs induce the secondary flow in the jet and decrease the jet concentration.

Cheng X.,National Research Institute for Rural Electrification
Shuili Fadian Xuebao/Journal of Hydroelectric Engineering | Year: 2013

Nowadays there exist many difficulties in national hydro-energy division. This paper designs and studies an evaluating decision support system for national hydro-energy resource division (NHRDS) to guide rational allocation and efficient use of hydro-energy. This system is based on J2EE development technology and an extension evaluation model, and it is equipped with three-dimensional properties of the role based access control (RBAC), river basin hydro-energy resources assessment function based on GIS, data mining function, and integration and intelligent reasoning functions of hydro-energy resources evaluation algorithm. The core technologies used for its design and development include hierarchical design techniques, AOP design, FSSH flexible architecture design technology and IoC (inversion of control technology). It has a good mechanism in security, augment ability, coupling and interactivity and can perform mass data mining and processing effectively. Pilot run results show that the system supports river basin hydro-energy resources division and intelligent decision for effective integration of river basin development and thus it lays a basis for further development toward nationwide application. © Copyright.

Zhang Z.,National Research Institute for Rural Electrification | Ye S.,Zhejiang Institute of Hydraulics and Estuary | Liao C.,Zhejiang Monitoring Center for Soil and Water Conservation
Proceedings - 2013 4th International Conference on Digital Manufacturing and Automation, ICDMA 2013 | Year: 2013

The urban road system is not only one of the most important urban infrastructures but also the important composition of urban ecological system. The road systems in many cities are suffering from various water-related problems, such as road water logging, increased drainage load resulted from concentrated runoff, waste of rainwater resource due to failure replenishing of the surface runoff to the groundwater system during the rainstorm period. The road waterlogging would affect its traffic function, even result in temporary regional traffic gridlock, and impair the quality and service life of the road works. The road surface runoff could contaminate the surrounding water environment, and under disturbance of vehicle wheels the dust accumulated on the road would pollute urban air when drying up. The analysis showed that the water-related problems are mainly resulted from manmade factors such as low design standard of road drainage system, poor environmental protection facilities for rainwater storage and infiltration, high-raised green belt, and the weaknesses of road building technology. Countermeasures were proposed, such as raising road drainage standard, innovating and popularizing road building materials and technology, and lowering the elevation of the green belts. Case study showed that the application of the pervious asphalt concrete as paving material and the adoption of lowering green belts, could significantly ease the street water logging, reduce the runoff pollution and urban drainage load, and improve the rain resources utilization. © 2013 IEEE.

Cheng X.,National Research Institute for Rural Electrification
Shuili Fadian Xuebao/Journal of Hydroelectric Engineering | Year: 2012

An extension model of regional river division is put forth to consider influences of technology, economy, zoology and so on, all of which are important factors in division of river carrying capacity. This model takes multi-index values as key decision factors, particularly for hydropower station in rural areas, and solves the conflict between technical exploiter and ecologic exploiter through extension transform and evaluation. Application to typical rivers in Zhejiang province is demonstrated. © right.

Xu Y.,China Institute of Technology | Zhang R.,China Institute of Technology | Zhang R.,China University of Technology | Cheng X.,National Research Institute for Rural Electrification
Shuili Fadian Xuebao/Journal of Hydroelectric Engineering | Year: 2014

Considering the shortage of real machine test data in design of pump-turbine for most of the pumped storage power stations in China, this paper presents a study of plant optimal operation and joint economic operation of hydropower and thermal power stations based on model test data of pump turbine, design data of pipe system, and efficiency characteristic curve of generator provided by the manufacturer to enhance the dynamic benefits of pumped storage stations. First, data of fuzzy dynamic characteristics were measured and a point-to-point modification on fixed dynamic characteristics of fuzzy data was made with an "exponential decay" static method in combination with the historical databases recorded by the computer monitoring system of pump-storage station. Then, the data of dynamic characteristics were corrected dynamically via an extension neural network training method based on a principle called "disjoint and linear equidistant head of unit". These two methods were coded in integrated modules that are embedded in a software system. Thus we have developed the system V3.0 for analysis of the dynamic characteristics of pump-turbine in pumped storage power station. Application shows that the characteristic equations of pump-storage station derived using the previously-mentioned modification and correction better describe the real cases and their solution produces satisfactory results. The present work would lay a basis for further study on plant optimization of pump-storage station and economic operation of joint hydro-thermal power stations. ©, 2014, Tsinghua University Press. All right reserved.

Mao J.,China Institute of Technology | Zhang R.,China Institute of Technology | Zhang R.,Zhejiang University of Technology | Wang W.,Zhejiang University of Technology | Cheng X.,National Research Institute for Rural Electrification
Shuili Fadian Xuebao/Journal of Hydroelectric Engineering | Year: 2015

Some large and medium-sized irrigation water pumps in China have run for a long time, and their existing dynamic characteristics are significantly different from the design conditions. To obtain more accurate dynamic characteristics of these pumps, first we obtained the raw data of dynamic characteristics from the raw material of pump source, design data, and efficiency curve of the motor, etc. Second, the dynamic characteristics were corrected using a static correction method of exponential decay and a dynamic training method of the extension neural network in combination with the measurements of pump sets in practical operation. Finally, we developed a large and medium-sized irrigation pumps dynamic characteristics analysis code V3.0 that integrates the two methods into a single module. Practical application shows that the modified equation of pump power characteristics that is used in this code, can describe the real engineering conditions. And typical characteristic curves produced by the code have a reasonable spacing and follow the same trend without intersecting. The data fitting errors of the code are low and the actual results of the code applications are satisfactory. This study would lay a basis for further study on the optimization of joint operation of the pumps and the gates. © All right reserved.

Cheng X.,National Research Institute for Rural Electrification
Shuili Fadian Xuebao/Journal of Hydroelectric Engineering | Year: 2015

Hydropower stations are featured with factors of dynamic uncertainties that are difficult to consider in a traditional deterministic dynamic model. This study analyzes three factors of fuzzy dynamic characteristics, given variable load, and uncertainty maintenance plan, and develops an uncertain dynamic model for optimization of hydropower station operation. This model solves the optimization problem using a spiral-vertical genetic algorithm (SVQA) and it is coded into a computer software module, upgrading the existing system of hydropower station dispatching. Its applications show that it is of has better performances and more effective in iteration and convergence to the final solution of an actual hydropower station dispatching problem than dynamic programming methods. © Copyright.

Zhang C.,CAS Institute of Policy and Management | Liu Y.,CAS Institute of Policy and Management | Qiao H.,National Research Institute for Rural Electrification
Physics and Chemistry of the Earth | Year: 2015

The relationship among the population, economy and water resources is complex, and the contradictions and conflicts will appear and aggravate with the rapid development of economy and society in Northeast China. Based on the statistical analysis of the available data, this paper depicted the static distribution characteristics of the population, economy and water resources of Northeast China in 2011. It was found that the spatial distribution of the population, economy and water resources was unbalanced in Northeast China. The water resources mismatched with the population and economy. The population and economy were relatively dense and developed in the southwestern part of Northeast China respectively, while the water resources was relatively scarce. However, the situations in the northern part of Northeast China were opposite to those in the southwestern part. The population-economy inconsistence indexes of the cities in northern part of Northeast China showed a significant trend of spatial aggregation and heterogeneity. The cities with lower (<1.5) and higher (>1) inconsistence indexes all faced the problem of water resources shortage. Applying geometric gravity center method and grey correlation model, the result indicated that there was relatively high spatial relevance and the relative deviation among the spatial dynamic distributions of the population, economy and water resources was large. The gravity centers of economy and per capita average annual total water resources moved westward, while the gravity center of population gravity center moved eastward in the period of 1997-2011 in Northeast China. It must be noted that, the migration trend of the economy gravity center was more significant than those of the population and water resources. © 2015 Elsevier Ltd.

Zhang C.,CAS Institute of Policy and Management | Dong L.,Beijing Engineering Corporation Ltd | Liu Y.,CAS Institute of Policy and Management | Qiao H.,National Research Institute for Rural Electrification
Sustainability (Switzerland) | Year: 2016

Water is an essential foundation for socio-economic development and environmental protection. As such, it is very critical for a city's sustainable development. This study analyzed the changes in water utilization structure and its impact factors using water consumption data for agricultural, industrial, domestic and ecological areas in the city of Tianjin, China from 2004 to 2013. On this base, the evolution law and impact factors of water utilization structure were depicted by information entropy and grey correlation respectively. These analyses lead to three main results. First, the total amount of water consumption in Tianjin increased slightly from 2004 to 2013. Second, the information entropy and equilibrium degree peaked in 2010. From 2004 to 2010, the water utilization structure tended to be more disordered and balanced. Third, the economic and social factors seemed to influence the water utilization structure, while the main impact factors were industrial structure, per capita green area, cultivated area, effective irrigation area, rural electricity consumption, animal husbandry output, resident population, per capita domestic water etc. © 2016 by the authors.

Dai S.,Hohai University | Cai X.,Hohai University | Xu J.,National Research Institute for Rural Electrification | Shu J.,National Research Institute for Rural Electrification | Li Y.,Hohai University
Journal of Hohai University | Year: 2013

According to the characteristics of diversion structures at small hydropower stations, a diversion structure safety assessment system, composed of safety, applicability, and durability indicators, was developed based on the safety evaluation principles. In order to reveal the subjective and objective evaluation factors in the diversion structure and overcome the disadvantages of the conventional weighting method, a coupled weighting method consisting of the index importance value and transference entropy is introduced in this paper. Based on comprehensive analysis of the membership function determination and result evaluation in the fuzzy theory, a safety evaluation model and fuzzy evaluation procedures were established. Application examples show that the safety evaluation method proposed in this study is feasible, effective, and can be widely applied to safety management of small-sized hydropower stations.

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