Ertan Hydropower Station

Ertan Hydropower Station, located in Panzhihua City, has the world's third highest double curvature arch dam in China, the largest underground powerhouse cavern group in Asia, and an installed capacity of 3.3 million kilowatts. It is the largest hydropower station in China built in the 20th century.

After the completion of the power station, a large number of tourist attractions have been left for tourists to visit. Since the first unit was put into operation in 1998, it has received nearly one million tourists. In October 2005, it won the title of "Ertan industrial tourism demonstration site" issued by the National Tourism Administration. About 46 km away from Panzhihua City, it is composed of dam, underground powerhouse, plunge pool, spillway tunnel and other main buildings.

Ertan Hydropower Station

Ertan Hydropower Station is located at the junction of Yanbian and Miyi counties in Panzhihua City, the southwest border of Sichuan Province. It is located at the downstream of Yalong River. The dam site is 33 km away from the intersection of Yalong River and Jinsha River, and 46 km away from Panzhihua City. It is the first hydropower station in the cascade development of Yalong River hydropower base. The upstream is Guandi Hydropower Station, and the downstream is Tongzilin hydropower station.

The maximum dam height of the hydropower station is 240 meters, the normal water level of the reservoir is 1200 meters above sea level, the total storage capacity is 5.8 billion cubic meters, the regulating storage capacity is 3.37 billion cubic meters, the total installed capacity is 3.3 million kilowatts, the guaranteed output is 1 million kilowatts, the average annual power generation is 17 billion kilowatt hours, and the investment is 28.6 billion yuan. The project is based on power generation and has other comprehensive utilization benefits.

It was started in September 1991, the first generating unit in July 1998 and completed in 2000. It is the largest power station built and put into operation in China in the 20th century.

Ertan lake of Ertan Hydropower Station is located in Panzhihua City, Sichuan Province, on the lower reaches of the mainstream of Yalong River. It is an important scenic spot and an integral part of Ertan National Forest Park. It is also an artificial lake formed by the construction of Ertan Hydropower Station. Therefore, it has become an important water conservation source in Shangri La ecosystem in Sichuan and Yunnan.

Historical evolution

On October 20, 1989, the former Ministry of energy issued the notice on the establishment of Ertan Hydropower Development Company (neren No. 1033).

On September 14, 1991, Ertan Hydropower Station, the first cascade in Yalong River Basin, started construction.

On February 10, 1995, Ertan Hydropower Development Co., Ltd. was restructured into Ertan Hydropower Development Co., Ltd. in accordance with the company law, establishing and improving the corporate governance structure and operating in accordance with the modern enterprise system.

On October 18, 1996, Ertan hydropower plant was established.

At the end of 2000, Ertan Hydropower Station was completed.

From August 2002 to February 2003, the company carried out internal reform, competing for posts, streamlining the organization, and preparing for the company's new development.

On October 20, 2003, the national development and Reform Commission issued a document specifying that "Ertan Hydropower Development Co., Ltd. shall be responsible for the development of water and energy resources of the Yalong River" and "be fully responsible for the construction and management of cascade hydropower stations in the Yalong River Basin".

technical parameter

Normal water level altitude of the reservoir: 1200m

Altitude of lowest operating water level for power generation: 1155m

Total storage capacity: 5.8 billion cubic meters;

Regulated storage capacity: 3.37 billion cubic meters;

Installed capacity: 3300 MW (6 sets of 550 MW Francis turbine generators)

Average power generation: 17 billion kwh

Guaranteed output power: 1000 MW

Annual utilization hours: 5162h

Elevation of dam crest: 1205m

Maximum dam height: 240m

Crest arc length: 774.69m

Crown top thickness: 11 m

Crown bottom thickness: 55.7m

The maximum center angle of arch ring is 91.49 degrees

The maximum overhanging degree of upstream surface is 0.18

The concrete volume of dam body is 4 million cubic meters.

Design Institute:

Chengdu survey, design and Research Institute of China Hydropower Consulting Group

Consultant group of Norway (AGN)

Construction unit:

Dam construction: Italy inbogillo company, France dummetz company, France gitim company, China Water Conservancy and Hydropower Bureau 8

Cavern construction: holtzmann company of Germany, holtief company of Germany

Location context

geological structure

The river valley at the dam site is narrow, the water surface is 80-100m wide in dry season, the mountains on both sides are 300-400M high, the valley slope on the left bank is 25-45 ° and the valley slope on the right bank is 30-45 ° respectively. The bedrock is composed of Permian basalt, syenite intruded in the later stage and altered basalt formed by intrusion. The rock mass is hard and complete. The thickness of riverbed overburden is generally 20-28m. There are only small faults and fracture zones in the dam site area, most of which are perpendicular or oblique to the riverbed at a medium high angle, and the extension is short and the continuity is poor. There is no permanent leakage in the reservoir area. Dapingzi, 80-83 km away from the dam site, has a large landslide of nearly 300 million cubic meters, but it is in a stable state. The basic seismic intensity in the dam site area is 7 degrees. The design intensity is 8 degrees.

Drainage area

The basin area above the dam site is 116400 square kilometers, accounting for about 90% of the whole basin area of Yalong River. The annual average discharge at the dam site is 1670 m3 / s, the annual runoff is 52.7 billion m3, the measured maximum discharge is 11100 m3 / s, which occurred on August 10, 1965; the historical maximum discharge is 16500 m3 / s, which occurred in 1863. The normal water level is 1200 meters, and the corresponding storage capacity is 5.8 billion cubic meters; the dead water level is 1155 meters, and the corresponding storage capacity is 2.43 billion cubic meters; the regulating storage capacity is 3.37 billion cubic meters, which is a seasonal regulating reservoir. The dam is designed according to the once-in-a-thousand-year flood, with the flood discharge of 20600 m3 / S; the corresponding reservoir water level of 1200 m, the check of 5000 year flood, with the discharge of 23900 m3 / s, the corresponding water level of 1203.5 m, the reservoir capacity of 6.18 billion m3, and the possible maximum flood discharge of 30000 m3 / s. The annual average sediment discharge at the dam site is 27.2 million tons, the annual average sediment concentration is 0.52 kg / m3, and the measured maximum sediment concentration is 9.58 kg / m3. The reservoir covers an area of 101 square kilometers, covers 1656 hectares of cultivated land and has a population of 26823.

Equipment structure

The hydro junction of the hydropower station is composed of concrete double curvature arch dam, underground powerhouse system on the left bank, flood discharge tunnel on the right bank, and wooden crane passage on the left bank. The whole project is located in a narrow valley within 2km from the upstream JINLONGGOU to the downstream santangou. The hub is a first-class project. The main hydraulic structures are concrete double curvature arch dam, discharge structure, water diversion channel, power house, main transformer room and switch station, which are first-class buildings. The log longitudinal timber passing machine system and the second dam are third-class buildings. The power station adopts five circuit 500kV outgoing lines and enters Sichuan power grid through ground switch station.

Hub dam

Ertan Project adopts double curvature arch dam. Due to narrow valley, high head and large discharge, flood discharge and energy dissipation facilities become an important part of Ertan Hydropower Station. The flood discharge structure of Ertan is designed according to the flood discharge of 20600 m3 / s with 1000 year return period and checked according to the flood discharge of 23900 m3 / s with 5000 year return period.

The dam is a concrete double curvature arch dam. In order to make the stress distribution of the dam body uniform, the thrust of the dam abutment is more inclined to the mountain, which is conducive to the stability of the dam body. The horizontal arch ring is a quadratic parabola, and the upstream surface of the arch crown beam is a cubic polynomial curve. The height of the dam crest is 1205m, the thickness of the top is 11m, the thickness of the bottom of the arch crown beam is 55.74m, the maximum thickness of the arch end is 58.51m, the thickness ratio is 0.232, the maximum center angle of the arch ring is 91.49 ° and the maximum overhanging degree of the upstream surface is 0.18. The arc length of dam crest is 775m. The concrete volume of dam body is 4 million cubic meters.

The spillway surface outlet is located in the center of the arch dam crest, with a total of 7 outlets, each of which is 11 meters wide and 11.5 meters high. The weir crest elevation is 1188.5 meters, and radial gate is installed. The dip angle drop sill with adjacent large differential of 30 ° and 20 ° is adopted, and the energy dissipator with diffluent teeth is set on the drop sill. There are 6 middle outlets in the arch dam. In order to make the water tongue collide with the surface hole water tongue at a large angle, the shape of the middle hole is upwarped. The outlet elevation is 1120m, the orifice section is square, and the size is 6m × 5m. In order to avoid the radial concentration of water flow, the pressure deflection of the middle hole is carried out on the plane, and the water tongue is dispersed horizontally and longitudinally with three groups of different angles of 30 °, 17 ° and 10 ° to avoid the overlap of water tongue and deepen the downstream scouring.

The two spillway tunnels are arranged on the right bank in a straight line with a short intake. The tunnel is an open flow tunnel with a square section, with a size of 13 m × 13.5 m (width × height). The bottom elevation of the entrance is 1163 meters. The length of No.1 Tunnel is 866.53 meters, and that of No.2 tunnel is 1197.33 meters. The bottom slope of the straight slope section of the two tunnels is 7.9% and 7% respectively. The concentrated drop of the longtoutou section is 70m, and the maximum velocity in the tunnel is about 45m / s. In order to prevent cavitation damage caused by high-speed flow, 5 and 7 aeration facilities are set up in the two spillways respectively. Aerator is a new type of aerator with U-channel flip bucket. The discharge capacity of the three flood discharge facilities can discharge the annual flood independently. In case of large flood, three sets of flood discharge facilities are used for joint flood discharge

Chinese PinYin : Er Tan Shui Dian Zhan