Journal of Hydroelectric Engineering

水力发电学报

Office Online

Included Databases

The journal is included in the following databases:
(i)Scopus,
(ii)The Chinese Science Citation Database Source Journals,
(iii)The Chinese Science Journal Abstract Database,
(iv)The Chinese Science and Technology Papers Statistics and Analysis Database,
(v)China Newspaper Subscription Guide Information Database,
(vi)Chinese Academic Journals (CD).


2017 Vol. 36, No. 3 Published: 2017-03-25

	1	Advancements in studies on reservoir ecological operation
		HUANG Qiang, ZHAO Menglong, LI Ying
		DOI: 10.11660/slfdxb.20170301
		Along with rapid development in socity and economy, ecosystem and environment become increasingly important. Traditional reservoir operation oriented at economic benefits and flood control has gradually transformed into ecological operation, and further toward comprehensive operation. Presently, most of the river basins in the world have different degrees of ecological problems, which are increasingly prominent, and more efforts are attracted to studies in ecological reservoir regulation. This type of regulation means to incorporate ecological factors into the traditional operation on the premise of meeting basic human water demands, aimed at restoring or maintaining the ecosystem of rivers. This paper discusses concepts of river ecological water demand and ecological regulation and analyzes ecological scheduling approaches considering a variety of ecological factors: ecological flow, sediment condition, and water quality, etc. Comprehensive dispatching of reservoirs is also discussed and its frontiers and future development are pointed out.
		2017 Vol. 36 (3): 1-11 [Abstract] ( 293 ) PDF (515 KB) ( 663 )

	12	Refined multi-objective cuckoo search algorithm for optimal dispatch of cascade hydropower stations
		YANG Xiaoping, HUANG Yujia, HUANG Qiang
		DOI: 10.11660/slfdxb.20170302
		This paper presents an improved multi-objective cuckoo search algorithm (IMOCS) to effectively solve the multi-objective joint optimization problem of cascade hydropower stations and optimize their generation benefit and capacity benefit. To avoid the slow convergence of traditional cuckoo search, this new algorithm adopts probabilities and steps of dynamic detection and is combined with a non-dominated sorting method and a crowding distance parameter as a strategy for maintaining external files. Its effectiveness was verified by using test functions. Then, we applied IMOCS to the Wu River cascade hydropower stations and obtained non-dominated solutions of uniform distribution. Finally, a subjective-objective method was used to determine the objective weights of a fuzzy decision model and choose a compromise plan, and a scheme for regulating the time variation in the reservoir stage of each station was obtained. The results show that the dispatch plan is effective and reliable in various operation conditions of different constraints and the improved algorithm is useful for optimizing joint operation of cascade hydropower stations.
		2017 Vol. 36 (3): 12-21 [Abstract] ( 235 ) PDF (849 KB) ( 504 )

	22	Water footprint-based fractional programming model for regional crop planting structure optimization
		CHEN Min, LI Yongping, WANG Guangqian, LI Tiejian, ZHOU Ya
		DOI: 10.11660/slfdxb.20170303
		This paper describes a crop planting structure optimization model based on the concept of water footprint. The water footprint theory is used to evaluate blue and green water footprints of regional main crops and then a fractional programming model is developed for maximizing the efficiency of agricultural water resource utilization by various crops with differences in crop features, spatial distribution, and water footprint. The model is applied to a real case of the Yangtze River-Yellow River-Lancang River headwaters area in Qinghai Province, and the crop planting structure is optimized by high profit and less irrigation water use for satisfying the local food demand. Compared with the current situation, the optimized structure suggests a significant increase in the planting area of vegetables with the highest profit and lowest water consumption and a slight increase in that of pea and potato with high profit and low water consumption, while maintaining the existing planting scale of crops with low profit and high water consumption such as wheat, highland barley and rapeseed. Results could be helpful for improving water utilization and providing basis on water management in the study area and other relevant areas.
		2017 Vol. 36 (3): 22-30 [Abstract] ( 217 ) PDF (410 KB) ( 374 )

	31	Hydraulic characteristics of swallow-tailed array flip buckets
		WANG Jing, DENG Jun, LV Li, YANG Zhengli
		DOI: 10.11660/slfdxb.20170304
		This article focuses on flood discharge and energy dissipation problems in a hydropower station ? the spillway is designed with a great range of capacity but its axis is nearly normal to the direction of river mainstream. For this spillway, we have developed a new swallow-tailed array flip bucket and examined its hydraulics and scour power using laboratory tests on a 1:60 scale model and comparing it with a continuous flip bucket and a swallow-tailed flip bucket. The experiment showed that the new flip bucket split the jet nappe into a multi-strand flow, making the water jet sufficiently stretched in a limited space. The multi-strand nappe was aerated obviously and falling down on the scour pool surface over an area larger than that of the other two flip buckets. The scope and intensity of the fluctuations caused by nappe plunging into the scour pool was decreased significantly so that its power of scour on the riverbed and river banks were much lowered. Thus, the swallow-tailed array flip bucket is an effective device of energy dissipation and erosion control for spillways with a large crossing angle to the river mainstream.
		2017 Vol. 36 (3): 31-37 [Abstract] ( 225 ) PDF (1510 KB) ( 433 )

	38	Discharge coefficient and flow division of trapezoidal sharp-crested side weirs in rectangular channel
		WANG Yingying, WANG Wen’e, HU Xiaotao
		DOI: 10.11660/slfdxb.20170305
		Side weirs of simple structure and high accuracy are usually installed along the side of main channels to spill and control water flow. Convenience and economic benefit in application could be achieved by combining their roles in flow rate measurement and flow division. In this study, we have conducted a laboratory experiment of trapezoidal sharp-crested side weirs of different crest angles (0°, 3°, 6° and 9°) in a rectangular channel under different discharges, and analyzed their flow characteristics and influencing factors. For different crest angles of side weirs, water surface profiles were measured and flow division ratios were calculated, and relationship of discharge coefficient versus influencing factors was examined. Results show that the flow division ratio at a fixed crest angle increases with the increasing inflow rate and the variation range of flow division decreases with the increasing crest angle. A flow division formula of high accuracy with a correlation coefficient of 0.921 was obtained. We also formulated a discharge coefficient formula by adding two inflow parameters of P/h1 and Fr1 and achieved a relative error of less than 8.1%, meeting the accuracy requirement of practical measurements. This work is a preliminarily study on the combined roles of flow rate measurement and flow division and it would provide a new direction for further study on side weirs and their engineering application.
		2017 Vol. 36 (3): 38-45 [Abstract] ( 144 ) PDF (877 KB) ( 323 )

	46	Active power fluctuations of generating units in grid connection experiment at Jinping-I hydropower station
		LI Ji’an, XI Guangqing, LI Yangyang, WU Falei
		DOI: 10.11660/slfdxb.20170306
		This paper presents an analysis on active power fluctuations in the grid connection experiment of the Jinping-I generating units, focusing on two causes of the fluctuations. The major cause was that in the cases of low water head, the adjustment parameter of local control unit (LCU) in the monitoring and control system was unable to be adapted to the active power regulation time of the turbine that became longer. Our analysis also revealed the other cause: the load-up operation was superimposed in phase on the second overshoot correction in the previous adjustment. Besides, water hammer could possibly play a role in this operation. Thus we suggest the following methods to solve the fluctuation problem. First, a manual interface for plus-or-minus operation of guide vane opening should be added to the computer monitoring and control system including the corresponding software. Second, the governor must be ensured to run in power feedback mode. Finally, the LCU should have an automatic function of changing its proportion integral derivative (PID) parameter and turn off its close-loop active power regulation in the cases of low water head operation.
		2017 Vol. 36 (3): 46-54 [Abstract] ( 187 ) PDF (359 KB) ( 352 )

	55	Numerical simulations of water hammer attenuation due to unsteady friction using a TVD scheme
		FAN Xiaodan, LIU Hansheng
		DOI: 10.11660/slfdxb.20170307
		The peak pressure of water hammer waves can be accurately captured by using traditional TVD schemes solving a quasi-constant friction model, but their attenuation and distortion cannot be exactly described by such models. Further studies on TVD schemes solving unsteady friction models are needed to eliminate the shortcoming of traditional models in pipeline design and management. In this work, we have developed a new numerical method for solving the one-dimensional water hammer equations based on the Sweby’s TVD scheme and Brunone’s IAB unsteady friction model and verified it through comparison with previous studies of classical water hammer experiment and application to engineering examples. It was compared with a traditional TVD scheme solving a quasi-constant friction model and the method of characteristics solving the unsteady friction model. Results show that our new method can capture the attenuation and distortion of water hammer waves in each of the calculated wave cycles and improve the accuracy in calculation of the resulting pressure peaks. And its numerical errors do not increase with simulation time, remaining less than 3% in peak pressure and no larger than 0.5 radian in phase shift for all the calculated wave cycles. With its computational cost comparable to that of traditional models, the new model is obviously superior for engineering application and research.
		2017 Vol. 36 (3): 55-62 [Abstract] ( 193 ) PDF (791 KB) ( 352 )

	63	Extraction of vibration signal features based on FastICA-EEMD
		ZHAO Jiajia, JIA Rong, WU Hua, DONG Kaisong, DANG Jian
		DOI: 10.11660/slfdxb.20170308
		This paper describes a method for extracting fault features from vibration signals based on fast independent component analysis (FastICA) and ensemble empirical mode decomposition (EEMD) to overcome the problems of mutual influence between vibration signals of a hydro-generator unit and noise disturbance to them. First, a vibration signal is decomposed into independent components by FastICA; then, each component is processed by EEMD and its effective intrinsic mode functions (IMFs) are selected by calculating the normalized energy and normalized correlation coefficients of all the IMFs; finally, these effective IMFs are used to extract its fault features. The results of simulation and application show that in comparison with other methods, this method can effectively suppress noise interference and it is more comprehensive and accurate in extraction of vibration feature signals for hydro-generator units, fully meeting practical engineering demands.
		2017 Vol. 36 (3): 63-70 [Abstract] ( 236 ) PDF (484 KB) ( 384 )

	71	Effects of initial relative density of sand on its deformation under cyclic spherical stress
		ZHAO Zhiyi, DENG Gang, WEN Yanfeng, ZHANG Xingxing, ZHANG Yinqi
		DOI: 10.11660/slfdxb.20170309
		Stress-path triaxial tests of sand samples were conducted under constant deviatoric stress with low speed cyclic loading and unloading of spherical stress to study deformation mechanism of saturated sand with two different initial relative densities. Influences of initial relative density on volumetric strain and shear strain were examined, and the following results are obtained: (1) volumetric strain and shear strain are accumulated obviously as the number of cycle increases; (2) when consolidation deviatoric stress is small, accumulative volumetric strain decreases and accumulative shear strain increases with the increasing initial relative density, but it has no effects on cyclic volumetric stain or shear strain; (3) when it is large, these accumulative strains and cyclic volumetric and shear strains all decrease considerably with the increasing initial relative density. With the number of cycles increasing, the effects of initial relative density on cyclic shear strain decrease gradually, and even disappear.
		2017 Vol. 36 (3): 71-77 [Abstract] ( 209 ) PDF (402 KB) ( 479 )

	78	Comparison and evaluation of design codes of hydraulic steel gates in China and America
		ZHANG Xuecai, WANG Zhengzhong, SUN Danxia, WANG Yue
		DOI: 10.11660/slfdxb.20170310
		The existing design codes of hydraulic steel gates in China and America are compared systematically in this paper. The content of Design code of steel gates for water resources and hydropower projects in China corresponds to that of hydraulic steel structures in America, while the commentary of this Chinese code corresponds to the Design code of spillway tainter gates and vertical lift gates in America. Our results show that between the Chinese and American codes, great differences exist in several aspects: design methods, calculation methods, design loads, layout of girders, design of skin plate, flow induced vibration, and choice of hoist. The American code is characterized by overall consideration, strong operability, and orientation to details; while the Chinese code by greater attention to design principles, more flexibility in application, and methods suitable for different project sites. Relative to the latter, the former is more advanced and scientific in design methods, calculation methods, corrosion control and ice control and more detailed in design loads, prevention of flow induced vibration, deflection of girders, and choice of hoist. However, both are similar in layout of girders and design of skin plate and generally lag behind the current achievements of research. Thus we suggest revising and updating the Chinese design code of hydraulic steel gates by absorbing the existing research achievements and the strong points of the American code. This is necessary and important and would provide a basis of internationalization in engineering designs for China's water conservancy and hydropower projects.
		2017 Vol. 36 (3): 78-89 [Abstract] ( 218 ) PDF (1026 KB) ( 538 )

	90	Analysis on schedule risks of diversion tunnel construction based on CSRAM
		XIAO Yao, ZHONG Denghua, REN Bingyu, YU Jia, ZHAO Mengqi, OU Liwen
		DOI: 10.11660/slfdxb.20170311
		This paper presents an analysis on construction schedule risks of diversion tunnels using a correlated schedule risk analysis model (CSRAM) considering correlation between risks and correlation between activities and assuming uncertainty in the duration of the activities that cause the risks. In this model, the risks are identified and qualified and their probability distributions are estimated, using the method of work breakdown structure-risk breakdown structure (WBS-RBS). And sensitivity of schedule risks is analyzed by changing the bounds of risk factors in probability calculation. The model can overcome the lack of schedule indexes and these correlations and the neglect of risk probability distribution in analysis of schedule risks. Application to practical diversion tunnel construction shows that our method is effective and satisfactory in calculation of completion probability, critical path, and other critical risk factors of the construction projects subjected to various risk factors. Thus this CSRAM-based method would lay a theoretical basis for schedule control and risk management in diversion tunnel construction.
		2017 Vol. 36 (3): 90-100 [Abstract] ( 200 ) PDF (688 KB) ( 351 )

	101	Comprehensive evaluation and prediction models for temperature conditions of arch dams
		WANG Youle, ZHOU Yihong, ZHAO Chunju, ZHOU Huawei, WANG Feng
		DOI: 10.11660/slfdxb.20170312
		To control the temperature of concrete dam blocks, we have developed a daily synthetic model for evaluation and prediction of concrete temperature conditions of arch dams. Based on the field monitoring data of typical concrete blocks, this model adopts a statistical sub-model for multiple regression analysis together with a combined index formula and a comprehensive exponential formula. It uses a small probability method to estimate the indexes of over-temperature control for a certain concrete age, i.e. allowable temperature and allowable temperature change rate, and determines over-temperature control nodes based on comparison with the temperature monitoring data. To meet the technical requirements by concrete dam construction, it applies a fuzzy matter-element theory in calculating feedback from the over-temperature nodes and evaluating indexes of construction schedule and temperature conditions and a genetic algorithm to optimize data consistency of index weights. Application to a practical project shows that the daily evaluation and prediction model can help in-site optimization and adjustment of concrete temperature control measures and has a good flexibility and convenience.
		2017 Vol. 36 (3): 101-112 [Abstract] ( 167 ) PDF (495 KB) ( 313 )

	113	Development and application of specific low heat portland cement for building ultra-high arch dams
		LI Wenwei, FAN Qixiang, LI Xinyu, WEN Zhaijun
		DOI: 10.11660/slfdxb.20170313
		Ultra high arch dams have higher stress levels and higher requirements of integrity, safety and durability of concrete dam bodies, which requires dam concrete to have higher strength grade, penetration resistance, frost resistance, and crack resistance. In this study, we have developed a specific low heat Portland cement that is suitable for the production of such dam concrete for ultra high arch dams. For this new type of cement, suitable contents of its four major mineral components were determined by considering the comprehensive effects of cement mineral composition, material strength and hydration heat. Its MgO content was controlled in the range of 4% - 5% to compensate thermal shrinkage during concrete temperature drop, and its specific surface area was limited to no greater than 340 m2/kg to reduce cement hydration rate at early stage. A new standard, Technical Requirements of Low Heat Portland Cement for Arch Dams, is suggested in this study and the corresponding design criteria are set to control cement quality. The dam concrete made of the specific cement that meets this standard will have a satisfactory performance in low unit water consumption, low adiabatic temperature rise, and high crack resistance. For this specific cement, a management and supervision system of quality control for the whole procedure has already been established and its large-scale steady production is achieved. Thus all this has laid a solid basis for application of low heat Portland cement in construction of 300m high arch dams and other hydropower projects.
		2017 Vol. 36 (3): 113-120 [Abstract] ( 230 ) PDF (723 KB) ( 498 )