Physical Simulation of Transient Process in Conduits of Hydropower Stations

2003 ◽  
Author(s):  
Jiandong Yang ◽  
Jinping Li ◽  
Yuehao Tang
Keyword(s):  
Transient Process ◽  
Physical Simulation ◽  
Transient Flow ◽  
Power Station ◽  
Small Fluctuation ◽  
Model Scale ◽  
Similarity Model ◽  
Model Similarity ◽  
Hydropower Stations ◽  
Flow Experiments

The transient process in the conduits of hydropower stations is a very complicated dynamic procedure coupled with fluid, machines, electricity, and even structure. The current methods used to analyze them separately cannot satisfy the design and the operation requirement of those large underground stations with long conduits. So it is necessary to develop a global physical simulation for the power station transients. As an initial discuss, this article focuses on the introduction of model similarity, model scale and some results about great fluctuation, small fluctuation and hydraulic interference in transient flow experiments.

Automated generation of photochemical reaction data by transient flow experiments coupled with online HPLC analysis

2020 ◽  
Vol 5 (5) ◽  
pp. 912-920
Author(s):  
Christian P. Haas ◽  
Simon Biesenroth ◽  
Stephan Buckenmaier ◽  
Tom van de Goor ◽  
Ulrich Tallarek
Keyword(s):  
Continuous Flow ◽  
Photochemical Reaction ◽  
Hplc Analysis ◽  
Transient Flow ◽  
Data Sets ◽  
Automated Generation ◽  
Reaction Data ◽  
Flow Experiments

Competing homo- and crossdimerization reactions between coumarin and 1-methyl-2-quinolinone are investigated by transient continuous-flow experiments combined with online HPLC, enabling the generation and acquisition of large reaction data sets.

Influence of Surge Tank and Relief Valve on Transient Flow Behaviour in Hydropower Stations

2011 ◽  
Author(s):  
Alireza Riasi ◽  
Ahmad Nourbakhsh
Keyword(s):  
Power Plants ◽  
Transient Flow ◽  
Flow Analysis ◽  
Internal Boundary ◽  
Transient Condition ◽  
Maximum Pressure ◽  
Surge Tank ◽  
Small Hydropower ◽  
Relief Valve ◽  
Hydropower Stations

Unsteady flow analysis in water power stations is one of the most important issues in order to predict undesirable pressure variations in waterways and also probable changes in rotor speed for the power plants safe operation. Installation of surge tank and relief valve is the two main methods for controlling of hydraulic transient. The relief valve is used in several medium and small hydropower stations instead of the surge tank and mounted on the penstock near the powerhouse. The recent generation of relief valves are reliable and beneficial and consist of fully control system that directly conducted by governor. This paper presents a numerical method for transient flow in hydropower stations using surge tank and relief valve. For this purpose the governing equations of transient flow in closed conduit are solved using the method of characteristics (MOC) using unsteady friction. Hydraulic turbine, surge tank and relief valve are considered as internal boundary conditions. The influence of surge tank and also relief valve on the maximum pressure in spiral case and turbine over speed has been studied for a real case. The results show that the transient condition is considerably improved by using a relief valve and this device can be mounted in lieu of an expensive surge tank.

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.

scholarly journals Model-based design of transient flow experiments for the identification of kinetic parameters

2020 ◽  
Vol 5 (1) ◽  
pp. 112-123 ◽  
Author(s):  
Conor Waldron ◽  
Arun Pankajakshan ◽  
Marco Quaglio ◽  
Enhong Cao ◽  
Federico Galvanin ◽  
...  
Keyword(s):  
Design Of Experiments ◽  
Kinetic Parameters ◽  
Transient Flow ◽  
Model Based ◽  
Precise Estimation ◽  
Flow Experiments

Rapid and precise estimation of kinetic parameters is facilitated by transient flow experiments designed using model-based design of experiments.

Transient flow experiments in a model immiscible polymer blend

1999 ◽  
Vol 43 (3) ◽  
pp. 815-827 ◽  
Author(s):  
Mario Minale ◽  
Paula Moldenaers ◽  
Jan Mewis
Keyword(s):  
Polymer Blend ◽  
Transient Flow ◽  
Immiscible Polymer Blend ◽  
Immiscible Polymer ◽  
Flow Experiments

ALTERNATYVIOS ENERGETIKOS STATINIŲ IR ĮRENGINIŲ POVEIKIO PASTATŲ ARCHITEKTŪRAI IR PAJŪRIO KRAŠTOVAIZDŽIAMS ASPEKTAI

2009 ◽  
Vol 33 (Supplement) ◽  
pp. 309-315 ◽  
Author(s):  
Petras Grecevičius ◽  
Jonas Abromas ◽  
Vytautas Dubra
Keyword(s):  
Sustainable Development ◽  
Wind Power ◽  
Natural Environment ◽  
Housing Development ◽  
Wave Power ◽  
Residential Areas ◽  
Power Station ◽  
The West ◽  
Power Stations ◽  
Hydropower Stations

Lately there are increasing signs of urbanization in the West Lithuanian landscapes which have an influence on the identity of the region, its historic and natural environment values. Housing development among seaside settlements is increasing. Lately some complexes of wind – power stations were installed. Unfortunately, they are built too close to residential areas, cultural heritage and landscape values. It is planned to install wind – and wave-power station fields in the high sea. Separate sun-power collectors are built on building roffs. Small-sized hydropower stations areconstructed or renovated. All these objects undoubtedly have an influence on building architecture and seaside lanscapes. On the basis of investigation data on some Lithuanian seaside settlements, useful planning and juridical suggestions are presented in the work to ensure sustainable development of the seaside region. Santrauka Pasaulinės bendruomenės deklaruojamos darnaus vystymosi nuostatos įpareigoja analizuoti atskirų šalies regionų ir gyvenviečių galimybes, išteklius tam, kad kuo greičiau itin pagerintume kiekvieno žmogaus gyvenimo kokybę. Pastaruoju laikotarpiu Vakarų Lietuvos teritorijos kraštovaizdyje vis labiau daugėja urbanizacijos ženklų, darančių negatyvų poveikį regiono identitetui, istorinės ir gamtinės aplinkos vertybėms. Tankėja užstatymas gyvenamaisiais pastatais tarp atskirų pajūrio gyvenviečių. Pastaruoju laikotarpiu regione įrengta keliolika vėjo jėgainių kompleksų, kai kur pastatytos pavienės jėgainės. Deja, jėgainės statomos labai arti gyvenamųjų teritorijų, kultūros paveldo ir kraštovaizdžio vertybių. Jau planuojama įrengti vėjo jėgainių laukus atviroje jūroje. Matyt, greit jūroje atsiras ir bangų energiją panaudojančios konstrukcijos. Ant pastatų stogų įrengiami pavieniai saulės kolektoriai. Renovuojamos arba statomos naujos nedidelės hidraulinės jėgainės. Regione yra perspektyvūs geoterminio vandens ištekliai. Visa tai neabejotinai jau daro įtaką architektūrinei pastatų bei pajūrio kraštovaizdžių raiškai. Ateityje ta įtaka dar labiau didės. Siekiant aukštos Lietuvos pajūrio kraštovaizdžių estetinės vertės, išsaugoti savitumą, būtina daug reglamentuojančių ir planavimo bei teisinių priemonių, kurios garantuotų aukštą kraštovaizdžio kokybę ne tik artimiausiais metais, bet ir tolimoje perspektyvoje. Šiame straipsnyje analizuojami kai kurie Lietuvos pajūrio gyvenviečių darnaus vystymosi aspektai, susieti su naujų energetinių įrenginių ir statinių poveikiu architektūrinei aplinkai, pateikiami preliminarūs siūlymai ieškant sprendimų, kaip naujus aplinkos elementus kuo tinkamiau išnaudoti gerinant pastatų architektūrą, praturtinant kraštovaizdžius.

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.

Application of Fuzzy Recognition Model for the Diversion Structures Safety Evaluation at Small Hydropower Stations

2014 ◽  
Vol 687-691 ◽  
pp. 3686-3690
Author(s):  
Ming Li ◽  
Xue Feng Yu ◽  
Yuan Dong Wei
Keyword(s):  
Safety Evaluation ◽  
Hydropower Station ◽  
Hydroelectric Power Station ◽  
Hydroelectric Power ◽  
Power Station ◽  
Small Hydropower ◽  
Recognition Model ◽  
Fuzzy Recognition ◽  
Hydropower Stations

In this passage is about the safety evaluation on the conveyance structure of small hydroelectric power station. Applying Binary comparative indicators to determine the weights and fuzzy recognition model on the conveyance structure of small hydroelectric power station’s assessment. Compared other models with fuzzy recognition model which will be explained in detail in the next section on a specific small hydropower station. The results show that the fuzzy recognition model is feasible and effective on safety evaluation on the conveyance structure of the hydroelectric power station.

scholarly journals Clearing Model for Day-ahead Market Considering Hydraulic Coupling Relationship of Multi-operator Cascade Hydropower Stations

2021 ◽  
Vol 252 ◽  
pp. 02011
Author(s):  
Huang Ningxin ◽  
Jing Zhaoxia
Keyword(s):  
Low Cost ◽  
Power Station ◽  
Coupling Relationship ◽  
Power Stations ◽  
Cascade Hydropower Stations ◽  
Hydraulic Coupling ◽  
Fixed Part ◽  
Relationship Of ◽  
Hydropower Stations ◽  
Clearing Mechanism

There is a hydraulic coupling relationship between the upstream and downstream of cascade hydropower stations, and they usually belong to different stakeholders. Traditional clearing mechanism may lead to the mismatch between the bid-winning power and the actual power generated by the downstream power stations, and the low-cost downstream power stations may lose some chance to generate, resulting in damage to social welfare. This paper analyzes the problems faced by multi-operator cascade hydropower stations participating in the day-ahead market. By deducing the generation coupling relationship between upstream and downstream cascade hydropower stations, it is found that the output of downstream hydropower stations can be divided into four parts: fixed part, adjustable part, the part coupled with the output of the upstream power station, the part coupled with the output of the upstream power station and the adjustable output. At last, day-ahead market clearing mechanism and settlement mechanism for downstream power stations to participate in bidding are proposed.

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