State Key Laboratory of Water Resources and Hydropower Engineering Science

Wuhan, China

State Key Laboratory of Water Resources and Hydropower Engineering Science

Wuhan, China
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Li C.,State Key Laboratory of Water Resources and Hydropower Engineering Science | Li C.,Huazhong University of Science and Technology | Mao Y.,Huazhong University of Science and Technology | Yang J.,State Key Laboratory of Water Resources and Hydropower Engineering Science | And 2 more authors.
Renewable Energy | Year: 2017

In this paper, the control problem of pumped storage unit (PSU) has been studied. A nonlinear generalized predictive control (NGPC) method has been applied to design the controller for a PSU. The NGPC controller is designed based on instantaneous linearization model of the control system, and the parameters of the linearized model are identified online by the recursive least square method (RLSM). Besides, in order to minimize the modelling error on initial state, a prior-knowledge learning method has been proposed to get the initial parameters for control model estimation. To verify the effectiveness of the NGPC controller, we chose a pumped-storage hydropower plant in China as the experimental subject and the simulation experiments respect to the control system are designed. The processes of start-up and speed disturbance under no-load condition have been simulated to testify the robustness and efficiency of the NGPC controller. Comparative experiments have been conducted, while the NGPC controller, a PID controller and a fractional order PID (FOPID) controller have been compared. Experimental results show that the designed NGPC could effectively restrain the oscillation of rotational speed in different working conditions of PSU and demonstrates higher robustness and stability than both the PID and FOPID controllers. © 2017 Elsevier Ltd


Yang N.,Nanjing University of Information Science and Technology | Zhang Y.,Nanjing University of Information Science and Technology | Duan K.,State Key Laboratory of Water Resources and Hydropower Engineering Science | Duan K.,North Carolina State University
Scientifica | Year: 2017

With the intensification of human activities over the past three decades in China, adverse effects on river ecosystem become more serious especially in the Hanjiang River. Xiangyang site is an important spawn ground for four domestic fishes in the downstream region of Hanjiang River. Based on the field survey results of macrophytes during 1997-2000 and 2013-2014, community succession of aquatic macrophytes at Xiangyang site was evaluated and discussed. Two-key ecologic-related hydrologic characteristics, flow regime and water level, were identified as the main influence factors. The EFC (environmental flow components) parameters were adopted to evaluate the alteration of flow regimes at Xiangyang site during 1941-2013. Evaluation results demonstrate a highly altered flow process after being regulated by reservoir. The flow patterns tend to be an attenuation process with no large floods occurring but a higher monthly low flow. Furthermore, the water level decreased and fluctuation reduced after the dam was built, which caused the decrease of biomass but favored the submerged macrophytes during 1995-2009. However, with the water level increasing after 2010 and gently fluctuating, due to uplift by the hydraulic projects downstream as well as the flow attenuation, the dominant position of submerged macrophytes will be weakened. © 2017 Na Yang et al.


Yu X.,State Key Laboratory of Water Resources and Hydropower Engineering Science | Yu X.,Hohai University | Zhang J.,Hohai University
Shuili Xuebao/Journal of Hydraulic Engineering | Year: 2016

Based on the one-dimensional hydraulic transients and the method of characteristics (MOC), the mathematical model of the vent in the tail race tunnel is established by using the Discrete Free-Gas Cavity Model (DGCM), and the thermodynamic properties of the gas is taking into account as well. A corresponding numerical model has been developed using the data of a real hydropower station, and the phenomenon of air inlet-two phase flow-air releases is investigated during transient process. The results show that air inlet can effectively relieve the negative pressure in the tunnel, but air releases can lead to a large impact pressure, which comes from the water column rejoin after the separation by the air, resulting in the direct water hammer. When the area of the vent is large, the impact pressure decreases with the increase of the area, when the area of the vent is small, the impact pressure increases with the increase of the area. According to its characteristics, the structure of a new type of vent is presented, i.e., the vent is fully open when the air flows in, and the vent is partly open when the air flows out. When the air releases area is about 10% of the air inlet area, the pressure oscillation is small. © 2016, China Water Power Press. All right reserved.


Li Y.Y.,Chinese Ministry of Water Resources | Cao J.T.,Chinese Ministry of Water Resources | Shen F.X.,Chinese Ministry of Water Resources | Xia J.,State Key Laboratory of Water Resources and Hydropower Engineering science | Xia J.,Chinese Academy of Sciences
Science China Earth Sciences | Year: 2014

Water is a critical natural resource upon which all social and economic activities and ecosystem functions depend. With a surprising social and economic development in the past decades, water has become an important constraint for China's sustainable development, and a matter concerning economic security, ecological security and national security of the country. Understanding the changes of water resources is greatly helpful in analyzing the impacts of climatic change, formulating plans for utilization and protection of water resources, and making water resource decisions. Based on China's national water resources assessment, the Mann-Kendall's test, and Morlet wavelet, we analyzed the changing trends and periods of China's renewable water resources during 1956-2010. The results as following: (1) There is no significant change trend of water resources on the countrywide scale during the period 1956-2010, the total water resources show a slight increasing trend, and the national annual average water resources during the period 1991-2010 increased by 1% relative to that of the period 1961-1990. (2) The changes of water resources in different level-I water resource regions vary significantly. Annual average water resources of the Haihe River and Yellow River regions in the northern China decreased 19% and 17% respectively in the past 20 years. Water resource increased in Southern and Northwestern rivers regions, particularly in the Northwest rivers region, with the increasing amplitude by nearly 10% in the past 20 years. (3) The inter-annual variation of national water resource became larger in the past 20 years, as compared with that of the period 1961-1990. The coefficients of water resource variation increased in Northwestern and Southwestern rivers regions, while the inter-annual variation tended to decrease in the Haihe and the Yellow River regions where significant decline of water resources happened. (4) A 14-year quasi-periodicity of the national water resource variation was detected, overlapping with various periodicities of water resources of different level-I water resource regions. Remarkable uniformity exists between the first or secondary primary periodicity of water resource variation in adjacent level-I water resource regions. © 2014 Science China Press and Springer-Verlag Berlin Heidelberg.


Fu L.,Hunan Electrical Science Research Institute | Kou P.G.,Hunan Electrical Science Research Institute | Cheng Y.G.,State Key Laboratory of Water Resources and Hydropower Engineering Science
Advances in Power and Energy Engineering - Proceedings of the 8th Asia-Pacific Power and Energy Engineering Conference, APPEEC 2016 | Year: 2016

The hydraulic turbine vibration is the most important factor influencing the safe operation of hydropower station. Because of the relatively wide vibration area, the regulating capacity of the Francis turbine has been greatly limited in the grid. In order to analyze the mechanisms of inducing vibration of the Francis turbine, the 3-D CFD model of Francis turbine has been established and analyzed using numerical simulation in this paper. And the results of CFD numerical simulation are compared with the data of field testing. Through the numerical simulation, the mechanisms of inducing vibration and the variation of the pressure fluctuation have been identified. And in this paper, the pressure fluctuation contours of Francis turbine has been drawn out by the calculation in 25 conditions and the study can guarantee the hydropower station’s safe and stable operation. © 2016 Taylor & Francis Group, London.


Cai X.,State Key Laboratory of Water Resources and Hydropower Engineering Science | He Z.,State Key Laboratory of Water Resources and Hydropower Engineering Science | Tang S.,State Key Laboratory of Water Resources and Hydropower Engineering Science | Chen X.,State Key Laboratory of Water Resources and Hydropower Engineering Science
Construction and Building Materials | Year: 2016

The abrasion erosion characteristics of concrete made from moderate heat Portland cement, fly ash, and silica fume were investigated via sandblasting test. In this study, the influences of fly ash, silica fume, impinging velocity and impinging angle on abrasion erosion resistance were taken into account. The test results indicated that the concrete fabricated with moderate heat Portland cement, fly ash and silica fume was applicable to the mass construction in need of either low hydration heat or high abrasion erosion resistance. The abrasion mass loss rate of concrete increased with the increasing of the impinging angle, and showed an exponential relation with the impinging velocity. Furthermore, the proposed method by Bitter and Neilson et al. was applied to analyze the abrasion erosion characteristics of concrete. The characteristics of each concrete mixture could be featured by four parameters (ε,φ,K, and n) according to this method, and they could be used for preliminarily predicting the abrasion erosion resistance of concrete. © 2016 Elsevier Ltd


Yang H.,State Key Laboratory of Water Resources and Hydropower Engineering Science | Fang K.,State Key Laboratory of Water Resources and Hydropower Engineering Science | Tu S.,State Key Laboratory of Water Resources and Hydropower Engineering Science
Advanced Materials Research | Year: 2011

An experimental program has been conducted to investigate the influence of limestone powder (LP) on fluidity, strength, and hydration of cement mortar. Four laboratory grinds were prepared using a ball mill. The relationship between roundness of the LP and water requirement of paste, fluidity and strength of mortar was studied. The influence of LP on hydration of cement was investigated. Hydration products were determined by X-ray diffraction (XRD) analysis. Test results show that the roundness of LP significantly affected the water requirement of paste, fluidity and strength of mortar. In addition, the sites for the nucleation and growth of hydration products, provided by LP, accelerate the hydration of cement at early ages. While the enhancement of cement hydration at later ages mainly due to the formation of calcium aluminate monocarbonate.


Liu X.,State Key Laboratory of Water Resources and Hydropower Engineering Science | Xu H.,Yangtze River Scientific Research Institute
Applied Mechanics and Materials | Year: 2012

The river reach in the center of Chongqing City lied in the fluctuant backwater of the Three Gorges Reservoir, and it was also the junction reach of the Jialing River to the Yangtze River. It's flow conditions and sediment movement was very complex. In the Three Gorges Reservoir 175m experimental operation period, the inherent laws of flow and sediment transport of river reach was changing under reservoir regulation. Prototype measured data for 20 years was analyzed at Jiulongpo, Zhuerqi, Jinshaqi and Cuntan sections. The results show that the association with the local flow were strong for the average sedimentation intensity in Flood season and the average erosion intensity later Flood season at the four sections. Different sediment erosion and deposition intensity corresponding to the flow was presented. According to the curve of discharge and cross-section mean velocity at Cuntan hydrologic section, the cross-section mean velocity corresponding to each flow is determined. On this basis, Sediment erosion and deposition change of river reach is analyzed at Three Gorges Project 175m operation periods. © (2012) Trans Tech Publications, Switzerland.


Yang H.,State Key Laboratory of Water Resources and Hydropower Engineering Science | Fang K.,State Key Laboratory of Water Resources and Hydropower Engineering Science | Tu S.,State Key Laboratory of Water Resources and Hydropower Engineering Science
Advanced Materials Research | Year: 2011

The present study aims to investigate the opportunity to largely substitute low heat Portland cement of mass concrete with supplementary cementitious materials. The pozzolanic reaction of two types of supplementary cementitious materials, phosphorous slag powder and fly ash, were determined by X-ray diffraction, differential thermal analysis-thermogravimetry and scanning electron microscopy from 28 to 90 days. The properties of mortar and mass concrete containing 30% of supplementary cementitious materials were also investigated. Results showed that supplementary cementitious materials could decrease the amount of calcium hydroxide, fill the capillary pores, thus making the mortar and mass concrete more compact and durable. Long-term strength of mass concrete containing 30% of supplementary cementitious materials were comparable (or even better) than the control concrete (without supplementary cementitious materials) at constant workability, while the Young's modulus was lower than the control concrete.


Ma G.,State Key Laboratory of Water Resources and Hydropower Engineering Science | Ma G.,Key Laboratory of Rock Mechanics in Hydraulic Structural Engineering | Zhou W.,State Key Laboratory of Water Resources and Hydropower Engineering Science | Zhou W.,Key Laboratory of Rock Mechanics in Hydraulic Structural Engineering | And 4 more authors.
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2011

A stochastic granule model is developed at mesomechanical level. A random distribution model for rockfill granule is generated by means of random simulation technique. In addition, the nonlinear contact algorithm is presented based on modified augmented Lagrangian algorithm. A simple linear softening damage model is employed to describe the stress and strain relationship of mesoscopic element, and the mechanical properties are distributed with a certain statistical function. The stochastic granule model of Maokou rockfill of Shuibuya rockfill dam is established. The simulated results show that the movement and deformation processes of rockfill granule agree well with the present experiments.

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