scholarly journals Study on hydraulic transient process of K hydropower station with low head, large flow and complex long tail water system

2021 ◽  
Vol 768 (1) ◽  
pp. 012003
Author(s):  
Li Gaohui ◽  
Zhang Mengjie ◽  
Chen Xiangrong ◽  
Zheng Quanchun ◽  
Cui Weijie ◽  
...  
Keyword(s):  
Transient Process ◽  
Water System ◽  
Hydropower Station ◽  
Long Tail ◽  
Hydraulic Transient ◽  
Low Head ◽  
Tail Water ◽  
Large Flow

Optimization of Two-Stage Closure Law of Turbine Wicket Gates and its Application

2012 ◽  
Vol 249-250 ◽  
pp. 636-641 ◽  
Author(s):  
Sheng Chen ◽  
Jian Zhang ◽  
Xiao Dong Yu
Keyword(s):  
Mathematical Model ◽  
Transient Process ◽  
Field Test ◽  
Hydropower Station ◽  
Two Stage ◽  
The Mathematical Model

Optimization of closure law is the priority selection in solving the guaranteed regulation calculation problems due to its simplicity and economy. This present study deals with the optimization of two-stage closure law of wicket gates, which has more advantages in control pressure and speed rise. The mathematical model of transient process is established by introducing the method of characteristic, whose correctness is validated by the field test. Then the model is applied to a specific hydropower station that only can employ closure law optimization to coordinate the contradiction between pressure and speed rise, for two-stage closure optimization. The achievements of the study can serve as a reference for similar projects.

scholarly journals Dynamic Safety Assessment in Nonlinear Hydropower Generation Systems

Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Shuang Li ◽  
Yong Yang ◽  
Qing Xia
Keyword(s):  
Transient Process ◽  
Safety Assessment ◽  
Hydropower Station ◽  
Generation System ◽  
Hydropower Generation ◽  
Safety Level ◽  
Fisher Discriminant ◽  
The Stability ◽  
Evolution Behavior ◽  
Hydropower Stations

This paper focuses on the stability problems in a hydropower station. To enable this study, we consider a nonlinear hydropower generation system for the load rejection transient process based on an existing hydropower station. Herein we identify four critical variables of the generation system. Then, we carry out the dynamic safety assessment based on the Fisher discriminant method. The dynamic safety level of the system is determined, and the evolution behavior in the transient process is also performed. The result demonstrates that the hydropower generation system in this study case can operate safely, which is in a good agreement with the corresponding theory and actual engineering. Thus, the framework of dynamic safety assessment aiming at transient processes will not only provide the guidance for safe operation, but also supply the design standard for hydropower stations.

Canadian species of Merlinius Siddiqi, 1970 and a diagnosis and description for Mulveyotus hyalacus n. gen., n. sp. (Nematoda: Tylenchorhynchidae)

1982 ◽  
Vol 60 (4) ◽  
pp. 521-529 ◽  
Author(s):  
R. V. Anderson ◽  
B. A. Ebsary
Keyword(s):  
Tail Length ◽  
New Combination ◽  
New Genus And Species ◽  
Long Tail ◽  
Lateral Field ◽  
Differential Characters ◽  
Low Head ◽  
Stylet Length ◽  
Thickened Cuticle ◽  
A New Species

Three new bisexual species of Merlinius Siddiqi, 1970, characterized by apically flattened heads and elongate–conoid tails with narrowly rounded or pointed ends, and a new genus and species (Tylenchorhynchidae) in Canada are described and illustrated. The distinguishing female characters of Merlinius plerorbus n. sp. are the constricted head, 16- to 17-μm-long stylet, 45- to 54-μm-long tail with 38–40 annules and a smoothly rounded terminus, and lobed spermathecae. Diagnostic for females of Merlinius circellus n. sp. are the continuous low head, 9- to 10-μm-long stylet, tail with 72–75 annules and a pointed terminus, and spherical spermathecae. The female of Merlinius tetylus n. sp. has a stylet length of 14 μm, a 98-μm-long tail with about 100 fine annules, and lobed spermathecae. Supplemental descriptive data for M. processus Siddiqi, 1979, a new species record for Canada, is provided, and included in a key to the species of Merlinius. Merlinius laminatus (Wu, 1969) Siddiqi, 1970 is transferred as a new combination to Scutylenchus Jairajpuri, 1971. Differential characters of Mulveyotus hyalacus n. gen., n. sp., are a body length of over 1 mm, alow, flattened continuous head, an areolated lateral field of three incisures, and a conoid tail over 100 μm long with a tapered smooth terminus of thickened cuticle comprising 24% of the tail length.

scholarly journals A Review of the Transient Process and Control for a Hydropower Station with a Super Long Headrace Tunnel

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2994 ◽  
Author(s):  
Wencheng Guo ◽  
Daoyi Zhu
Keyword(s):  
Design Optimization ◽  
Transient Process ◽  
Operating Conditions ◽  
Research Progress ◽  
Hydropower Station ◽  
Operation Conditions ◽  
Hydraulic Design ◽  
Headrace Tunnel ◽  
And Control ◽  
Hydropower Stations

The hydropower station with a super long headrace tunnel is a significant development type for hydropower energy. By constructing a super long headrace tunnel, the huge natural water fall head can be utilized to generate more electricity. With the development of hydropower energy, a hydropower station with a super long headrace tunnel becomes more and more competitive. Compared with a hydropower station with a short headrace tunnel, the transient process and control for a hydropower station with a super long headrace tunnel is much more complicated and becomes an intractable challenge. It is well known that the transient process and control is the basis of the design and operation of a hydropower station. To overcome the challenge of the transient process and control, much research has been carried out. This paper provides a systematic review on the latest research progress of the transient process and control for hydropower stations with a super long headrace tunnel. Firstly, two key issues for the transient process and control, i.e., hydraulic design optimization of the surge tank and operation control of unit, are illuminated. Secondly, for both single surge tanks and surge tanks with special types or combinations, the hydraulic design optimization methods are described. The most disadvantageous design and advantageous operation of surge tanks under combined operating conditions are discussed. Thirdly, the stability and regulation quality of the hydro-turbine governing system under isolated and grid-connected operation conditions are presented. Finally, some trends and recommendations for future research directions are made. A research thought for establishing the complete theory and application system of the transient process and control for hydropower stations with a super long headrace tunnel from the perspective of multi-slice and multi-scale is proposed.

scholarly journals Study on Selection of Pressure Regulating Valve for Hydropower Station with Both Surge Tank and Pressure Regulating Valve

2018 ◽  
Vol 246 ◽  
pp. 01033
Author(s):  
Tianchi Zhou ◽  
Gaohui Li ◽  
Yimin Chen
Keyword(s):  
Transient Process ◽  
Maximum Flow ◽  
Hydropower Station ◽  
Surge Tank ◽  
Calculation Results ◽  
Practical Engineering ◽  
Spiral Case ◽  
Unit Speed ◽  
Working Principle ◽  
Selection Of

The transient process in the hydropower station with both surge tank and pressure regulating valve is quite complicated and also critical to operation safety. According to the pressure regulating valve working principle, the influence of the valve diameter on the unit speed and spiral case pressure was analyzed theoretically. Mathematical models of the surge tank and pressure regulating valve in the hydropower station were established based on the characteristic method. In a practical engineering, numerical simulation of large fluctuation and hydraulic disturbance transient process are conducted, verifying the correctness of the theoretical analysis. Based on the calculation results, three principles for selecting the valve diameter are concluded: first, making sure the unit speed meet the regulating guarantee requirements when guide vanes fast close; second, the maximum spiral case pressure of two times should be approximate to each other by controlling the superposition of surge wave and water hammer; third, the maximum flow of the valve should be as close to the rated flow of the turbine as possible. The principles are helpful for selecting the valve diameter in similar hydropower station.

MATLAB Calculation of Hydraulic Transients in Hydropower Simulation Application

2011 ◽  
Vol 219-220 ◽  
pp. 346-350
Author(s):  
Heng Lei ◽  
Ying Li
Keyword(s):  
Process Analysis ◽  
Operation Mode ◽  
Water System ◽  
Transition Process ◽  
Hydropower Station ◽  
Power Station ◽  
Hydraulic Transients ◽  
Power Operation ◽  
System Design Optimization ◽  
The Mathematical Model

In hydropower station in the operation of total with hydraulic transient process of the power station on the transition process analysis and calculation is quite important. This paper introduces the today's advanced scientific computing software MATLAB, and using the software of the Zipingpu hydropower station hydraulic transients from the mathematical model and calculation simulation etc is analyzed and calculated with research, in order to seek appropriate power operation mode, unit close regularities. For power station and water system design optimization, safe operation, provides the basis.

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