The Influence of Pump-Turbine Specific Speed on Hydraulic Transient Processes

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GILJEN, Zdravko ;NEDELJKOVIĆ, Miloš ;CHENG, Yongguang .
The Influence of Pump-Turbine Specific Speed  on Hydraulic Transient Processes. 
Strojniški vestnik - Journal of Mechanical Engineering, [S.l.], v. 70, n.5-6, p. 231-246, january 2024. 
ISSN 0039-2480.
Available at: <https://www.sv-jme.eu/article/influence-of-pump-turbine-specific-speed-on-hydraulic-transient-processes/>. Date accessed: 20 dec. 2024. 
doi:http://dx.doi.org/10.5545/sv-jme.2023.776.
Giljen, Z., Nedeljković, M., & Cheng, Y.
(2024).
The Influence of Pump-Turbine Specific Speed  on Hydraulic Transient Processes.
Strojniški vestnik - Journal of Mechanical Engineering, 70(5-6), 231-246.
doi:http://dx.doi.org/10.5545/sv-jme.2023.776
@article{sv-jmesv-jme.2023.776,
	author = {Zdravko  Giljen and Miloš  Nedeljković and Yongguang  Cheng},
	title = {The Influence of Pump-Turbine Specific Speed  on Hydraulic Transient Processes},
	journal = {Strojniški vestnik - Journal of Mechanical Engineering},
	volume = {70},
	number = {5-6},
	year = {2024},
	keywords = {hydraulic transients; pump-turbine; influence of the specific speed; load rejection; working point trajectory; method of characteristics; },
	abstract = {The main porpose of this paper is to perform and present at transient process analysis on the influence of different specific speeds (nq) of the three-model pump-turbines that may implemented at the hydropower pump storage plant (HPSP) Bajina Basta, Serbia. The intention is to analyze the operation regimes along the S-shaped characteristic curve, which creates difficulties in calculations during the load-rejection process. These problems are manifested by an unusual increase in water pressure, followed by an increase in machine vibrations, thus threatening the stability of machine operation. The subject of this research is the four-quadrant (4Q) characteristic curves, presented in the form of Suter curves (the head and momentum parameters (Wh and Wm), in dependence of angle (θ)) for different wicket gate openings, of the three pump-turbine models with different specific speeds (nq = 27, nq = 38 and nq = 50). These 4Q characteristics are used as input data for numerical code developed to calculate the simultaneous load rejection of both pump-turbines. The numerical code is based on the method of characteristics and applied to the test case at HPSP. This is especially relevant when dealing with characteristic S-shaped curves that may lead to serious instability in operation during the transient process. The calculation results show changes in the pressure, speed of rotation and discharge of the machine operation regimes, but the important findings are reflected in further application of the results to determine the parametric flow and speed (Q11 and n11) trajectories of the operating points, where the unstable behavior of a pump-turbine operating in turbine mode is presented and periodically the trajectories also pass through the reverse pump zone.},
	issn = {0039-2480},	pages = {231-246},	doi = {10.5545/sv-jme.2023.776},
	url = {https://www.sv-jme.eu/article/influence-of-pump-turbine-specific-speed-on-hydraulic-transient-processes/}
}
Giljen, Z.,Nedeljković, M.,Cheng, Y.
2024 January 70. The Influence of Pump-Turbine Specific Speed  on Hydraulic Transient Processes. Strojniški vestnik - Journal of Mechanical Engineering. [Online] 70:5-6
%A Giljen, Zdravko 
%A Nedeljković, Miloš 
%A Cheng, Yongguang 
%D 2024
%T The Influence of Pump-Turbine Specific Speed  on Hydraulic Transient Processes
%B 2024
%9 hydraulic transients; pump-turbine; influence of the specific speed; load rejection; working point trajectory; method of characteristics; 
%! The Influence of Pump-Turbine Specific Speed  on Hydraulic Transient Processes
%K hydraulic transients; pump-turbine; influence of the specific speed; load rejection; working point trajectory; method of characteristics; 
%X The main porpose of this paper is to perform and present at transient process analysis on the influence of different specific speeds (nq) of the three-model pump-turbines that may implemented at the hydropower pump storage plant (HPSP) Bajina Basta, Serbia. The intention is to analyze the operation regimes along the S-shaped characteristic curve, which creates difficulties in calculations during the load-rejection process. These problems are manifested by an unusual increase in water pressure, followed by an increase in machine vibrations, thus threatening the stability of machine operation. The subject of this research is the four-quadrant (4Q) characteristic curves, presented in the form of Suter curves (the head and momentum parameters (Wh and Wm), in dependence of angle (θ)) for different wicket gate openings, of the three pump-turbine models with different specific speeds (nq = 27, nq = 38 and nq = 50). These 4Q characteristics are used as input data for numerical code developed to calculate the simultaneous load rejection of both pump-turbines. The numerical code is based on the method of characteristics and applied to the test case at HPSP. This is especially relevant when dealing with characteristic S-shaped curves that may lead to serious instability in operation during the transient process. The calculation results show changes in the pressure, speed of rotation and discharge of the machine operation regimes, but the important findings are reflected in further application of the results to determine the parametric flow and speed (Q11 and n11) trajectories of the operating points, where the unstable behavior of a pump-turbine operating in turbine mode is presented and periodically the trajectories also pass through the reverse pump zone.
%U https://www.sv-jme.eu/article/influence-of-pump-turbine-specific-speed-on-hydraulic-transient-processes/
%0 Journal Article
%R 10.5545/sv-jme.2023.776
%& 231
%P 16
%J Strojniški vestnik - Journal of Mechanical Engineering
%V 70
%N 5-6
%@ 0039-2480
%8 2024-01-24
%7 2024-01-24
Giljen, Zdravko, Miloš  Nedeljković, & Yongguang  Cheng.
"The Influence of Pump-Turbine Specific Speed  on Hydraulic Transient Processes." Strojniški vestnik - Journal of Mechanical Engineering [Online], 70.5-6 (2024): 231-246. Web.  20 Dec. 2024
TY  - JOUR
AU  - Giljen, Zdravko 
AU  - Nedeljković, Miloš 
AU  - Cheng, Yongguang 
PY  - 2024
TI  - The Influence of Pump-Turbine Specific Speed  on Hydraulic Transient Processes
JF  - Strojniški vestnik - Journal of Mechanical Engineering
DO  - 10.5545/sv-jme.2023.776
KW  - hydraulic transients; pump-turbine; influence of the specific speed; load rejection; working point trajectory; method of characteristics; 
N2  - The main porpose of this paper is to perform and present at transient process analysis on the influence of different specific speeds (nq) of the three-model pump-turbines that may implemented at the hydropower pump storage plant (HPSP) Bajina Basta, Serbia. The intention is to analyze the operation regimes along the S-shaped characteristic curve, which creates difficulties in calculations during the load-rejection process. These problems are manifested by an unusual increase in water pressure, followed by an increase in machine vibrations, thus threatening the stability of machine operation. The subject of this research is the four-quadrant (4Q) characteristic curves, presented in the form of Suter curves (the head and momentum parameters (Wh and Wm), in dependence of angle (θ)) for different wicket gate openings, of the three pump-turbine models with different specific speeds (nq = 27, nq = 38 and nq = 50). These 4Q characteristics are used as input data for numerical code developed to calculate the simultaneous load rejection of both pump-turbines. The numerical code is based on the method of characteristics and applied to the test case at HPSP. This is especially relevant when dealing with characteristic S-shaped curves that may lead to serious instability in operation during the transient process. The calculation results show changes in the pressure, speed of rotation and discharge of the machine operation regimes, but the important findings are reflected in further application of the results to determine the parametric flow and speed (Q11 and n11) trajectories of the operating points, where the unstable behavior of a pump-turbine operating in turbine mode is presented and periodically the trajectories also pass through the reverse pump zone.
UR  - https://www.sv-jme.eu/article/influence-of-pump-turbine-specific-speed-on-hydraulic-transient-processes/
@article{{sv-jme}{sv-jme.2023.776},
	author = {Giljen, Z., Nedeljković, M., Cheng, Y.},
	title = {The Influence of Pump-Turbine Specific Speed  on Hydraulic Transient Processes},
	journal = {Strojniški vestnik - Journal of Mechanical Engineering},
	volume = {70},
	number = {5-6},
	year = {2024},
	doi = {10.5545/sv-jme.2023.776},
	url = {https://www.sv-jme.eu/article/influence-of-pump-turbine-specific-speed-on-hydraulic-transient-processes/}
}
TY  - JOUR
AU  - Giljen, Zdravko 
AU  - Nedeljković, Miloš 
AU  - Cheng, Yongguang 
PY  - 2024/01/24
TI  - The Influence of Pump-Turbine Specific Speed  on Hydraulic Transient Processes
JF  - Strojniški vestnik - Journal of Mechanical Engineering; Vol 70, No 5-6 (2024): Strojniški vestnik - Journal of Mechanical Engineering
DO  - 10.5545/sv-jme.2023.776
KW  - hydraulic transients, pump-turbine, influence of the specific speed, load rejection, working point trajectory, method of characteristics, 
N2  - The main porpose of this paper is to perform and present at transient process analysis on the influence of different specific speeds (nq) of the three-model pump-turbines that may implemented at the hydropower pump storage plant (HPSP) Bajina Basta, Serbia. The intention is to analyze the operation regimes along the S-shaped characteristic curve, which creates difficulties in calculations during the load-rejection process. These problems are manifested by an unusual increase in water pressure, followed by an increase in machine vibrations, thus threatening the stability of machine operation. The subject of this research is the four-quadrant (4Q) characteristic curves, presented in the form of Suter curves (the head and momentum parameters (Wh and Wm), in dependence of angle (θ)) for different wicket gate openings, of the three pump-turbine models with different specific speeds (nq = 27, nq = 38 and nq = 50). These 4Q characteristics are used as input data for numerical code developed to calculate the simultaneous load rejection of both pump-turbines. The numerical code is based on the method of characteristics and applied to the test case at HPSP. This is especially relevant when dealing with characteristic S-shaped curves that may lead to serious instability in operation during the transient process. The calculation results show changes in the pressure, speed of rotation and discharge of the machine operation regimes, but the important findings are reflected in further application of the results to determine the parametric flow and speed (Q11 and n11) trajectories of the operating points, where the unstable behavior of a pump-turbine operating in turbine mode is presented and periodically the trajectories also pass through the reverse pump zone.
UR  - https://www.sv-jme.eu/article/influence-of-pump-turbine-specific-speed-on-hydraulic-transient-processes/
Giljen, Zdravko, Nedeljković, Miloš, AND Cheng, Yongguang.
"The Influence of Pump-Turbine Specific Speed  on Hydraulic Transient Processes" Strojniški vestnik - Journal of Mechanical Engineering [Online], Volume 70 Number 5-6 (24 January 2024)

Authors

Affiliations

  • University of Belgrade, Faculty of Mechanical Engineering, Serbia 1
  • Wuhan University, State Key Laboratory of Water Resources and Hydropower Engineering Science, China 2

Paper's information

Strojniški vestnik - Journal of Mechanical Engineering 70(2024)5-6, 231-246
© The Authors 2024. CC BY 4.0 Int.

https://doi.org/10.5545/sv-jme.2023.776

The main porpose of this paper is to perform and present at transient process analysis on the influence of different specific speeds (nq) of the three-model pump-turbines that may implemented at the hydropower pump storage plant (HPSP) Bajina Basta, Serbia. The intention is to analyze the operation regimes along the S-shaped characteristic curve, which creates difficulties in calculations during the load-rejection process. These problems are manifested by an unusual increase in water pressure, followed by an increase in machine vibrations, thus threatening the stability of machine operation. The subject of this research is the four-quadrant (4Q) characteristic curves, presented in the form of Suter curves (the head and momentum parameters (Wh and Wm), in dependence of angle (θ)) for different wicket gate openings, of the three pump-turbine models with different specific speeds (nq = 27, nq = 38 and nq = 50). These 4Q characteristics are used as input data for numerical code developed to calculate the simultaneous load rejection of both pump-turbines. The numerical code is based on the method of characteristics and applied to the test case at HPSP. This is especially relevant when dealing with characteristic S-shaped curves that may lead to serious instability in operation during the transient process. The calculation results show changes in the pressure, speed of rotation and discharge of the machine operation regimes, but the important findings are reflected in further application of the results to determine the parametric flow and speed (Q11 and n11) trajectories of the operating points, where the unstable behavior of a pump-turbine operating in turbine mode is presented and periodically the trajectories also pass through the reverse pump zone.

hydraulic transients; pump-turbine; influence of the specific speed; load rejection; working point trajectory; method of characteristics;