Operation and Control Of Three-Stage Half-Opened Cascaded Hydropower Station

2010 ◽  
Author(s):  
Biao Han ◽  
Honggang Fan ◽  
Naixiang Chen
Keyword(s):  
Hydropower Station ◽  
And Control ◽  
Cascaded Hydropower Station

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 Microseismic Monitoring of Energy Changes in Deep Tunnels during the TBM Tunneling of the Jinping II Hydropower Station

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Duanyang Zhuang ◽  
Ke Ma ◽  
Chunan Tang ◽  
Zhengzhao Liang ◽  
Zhenwei Wang
Keyword(s):  
Control Method ◽  
Microseismic Monitoring ◽  
Surrounding Rock ◽  
Hydropower Station ◽  
Rock Masses ◽  
Spatial And Temporal Patterns ◽  
Tunnel Section ◽  
Headrace Tunnel ◽  
Jinping Ii Hydropower Station ◽  
And Control

The TBM tunneling at the Jinping II hydropower station in Southwest China has received extensive concerns around the world because of its large engineering scale and the high rockburst risks faced in the tunnel advancement. The associated energy changes of rockbursts and control method for safe TBM tunneling are to be further investigated. A movable microseismic (MS) monitoring system was established to capture the MS events and rockbursts when the TBM excavated the headrace tunnel #1 at the Jinping II hydropower station. The spatial and temporal patterns of the energy changes in the tunnel rock masses were studied. Meanwhile, the evolution of a rockburst encountered in front of the TBM excavation face was revealed, and the performance of the top pilot tunnel method on the reduction of the rockburst risks in the headrace tunnel #1 was evaluated based on the energy changes of the surrounding rock masses. It can be concluded that energy accumulation and energy release firstly occurred in the surrounding rock masses at the southern end of the top pilot tunnel section of the headrace tunnel #1. Then, energy transference of the rock masses took place from the southern end to northwest of the top pilot tunnel giving rise to the occurrence of a moderate rockburst about 30 m in front of the tunnel. However, no rockbursts appeared when the TBM excavated through the top pilot tunnel section of the headrace tunnel #1. Therefore, the top pilot tunnel method really works in reducing the risks of rockbursts during the TBM tunneling in deep tunnels.

scholarly journals Blast Vibration Control in A Hydropower Station for the Safety of Adjacent Structure

2020 ◽  
Vol 10 (18) ◽  
pp. 6195
Author(s):  
Yuanjun Ma ◽  
Changwu Liu ◽  
Ping Wang ◽  
Jun Zhu ◽  
Xianliang Zhou
Keyword(s):  
Concrete Structure ◽  
Plain Concrete ◽  
Hydropower Station ◽  
Charge Weight ◽  
Blasting Vibration ◽  
Blast Vibration ◽  
Vibration Data ◽  
Roller Compacted Concrete ◽  
The Right ◽  
And Control

The transverse cofferdam in Xiangjiaba hydropower station was a water retaining concrete structure with a length of 126 m, a width of 12 m, and a height of 25.2 m, consisting of masonry, plain concrete structure (PC), and roller compacted concrete (RCC), which had to be demolished by blasting after the dam was built. There were many precise instruments nearby the cofferdam which had strict restrictions on blasting vibration. Therefore, the cofferdam was divided into six blasting regions, including land blasting and underwater blasting. Blasting parameters and blasting network structure were accurately designed and continuously optimized through blast-induced vibration test results. At nine measurement points in different locations, 57 blast vibration data were recorded. Consequently, 1386 holes with an explosive weight of 9641.3 kg were detonated in land blasting. The highest levels of vibration were recorded as 8.74 cm/s in the desilting tunnel on the right of the cofferdam. The explosives up to 11887.7 kg were detonated in an underwater blasting. According to the analysis of the law of vibration attenuation, the blast vibration value was reduced to 7.65 cm/s. The results showed that the research on the attenuation law of blasting vibration can effectively increase the charge weight per delay and control the blast-induced vibration. Consequently, the peak particle velocity (PPV) of underwater blasting could be predicted by analyzing the PPV of land blasting in same structure, which provided the basis for the design of underwater blasting parameters. A reliable method for cofferdam demolition in hydropower station was proposed, which provided a reference for similar projects.

scholarly journals Investigation and Control of the Blasting-Induced Ground Vibration under Cold Condition

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Yingguo Hu ◽  
Zhaowei Yang ◽  
Erlei Yao ◽  
Meishan Liu ◽  
Yu Rao
Keyword(s):  
Rock Mass ◽  
Mechanical Performance ◽  
Wave Attenuation ◽  
Ground Vibration ◽  
Simulation Method ◽  
Hydropower Station ◽  
Charge Weight ◽  
Blasting Excavation ◽  
Cold Condition ◽  
And Control

This paper focuses on the investigation and control of the blasting-induced ground vibration under cold condition. The mechanical performance and wave propagation characteristics of the frozen rock mass are quite different from that of the conventional condition. Laboratory tests were implemented to investigate the wave impedance of rock mass in the frozen, saturated, normal, and drying states. Results reveal the longitudinal wave velocity could be enlarged by 40 percent in the frozen state. Then long-term monitoring of blasting vibration was implemented based on the blasting excavation of the Fengman hydropower station reconstruction project in the north of China. Results demonstrate the PPV and frequency both attenuate much slower when the rock mass is frozen, and the obvious turning points of PPV could be found between different temperatures, where the change of the PPV relationship happens. At last, numerical simulation of the blasting seismic wave attenuation and the response in the protected structure was implemented. The equivalent freezing simulation method was proposed and verified with the site experiment data. Results demonstrate that the attenuation coefficient decreases obviously as the frozen depth of the rock mass increases. The dynamic degree response in structure is much stronger and the maximum charge weight per delay was limited more strictly under the frozen condition. A most adverse frozen depth was determined when the charge weight per delay gets the minimum value. With the above control approaches, a total of 676 blasting was completed in Fengman hydropower station reconstruction and no case of excessive measurement could be found.

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