Yunnan is building the world's largest green energy engineering base. Once completed, it will kill two Three Gorges areas.

Our country is one of the countries with the best development of hydropower stations in the world. It has many world-famous large hydropower stations. The most famous among them is the Three Gorges Hydropower Station. Its total installed capacity is 22.4 million kilowatts, which is currently the largest hydropower station in the world. The largest hydropower station in the world, it is not only a great water conservancy project, but also attracts Chinese and foreign tourists to visit this century project.

Records can often be broken. The Jinsha River is the largest hydropower base in China, with more than 20 hydropower stations planned for the entire basin. Among them, the Wudongde Hydropower Station, a super hydropower station located on the lower reaches of the Jinsha River at the junction of Sichuan and Yunnan, is the fourth super hydropower station in my country and the seventh in the world to reach the 10 million kilowatt level. During its construction, it used Many smart "black technologies" are dedicated to building the smartest dam in the world, which will be completed and put into operation in 2021.

In the future, the four cascade power stations on the Jinsha River - Wudongde, Baihetan, Xiluodu and Xiangjiaba - will have an installed capacity of 46.46 million kilowatts, equivalent to two "Three Gorges Projects", with annual power generation With a capacity of approximately 190 billion kilowatt-hours, it will become the world's largest green energy engineering base iconic in the 21st century.

The Wudongde Hydropower Station has an investment of more than 100 billion yuan, and the Three Gorges Corporation is responsible for the development and construction. The power station mainly produces electricity, but also takes into account flood control and shipping. It is the backbone power source of the "West-East Power Transmission". The power station has a designed normal water storage level of 975 meters and is expected to be put into operation in 2020. Its total installed capacity is equivalent to the installed capacity of two Three Gorges Hydropower Stations.

Due to the complex topography and geological conditions of the hydropower station construction area, the canyon is deep, the slope height on both sides is about 1500 to 1800 meters, and the slope slope is 60° to 70°. Deep foundation pits and high cofferdams are one of the key technical problems of the Wudongde Hydropower Station project. The depth of the river bed cofferdam basic covering layer is between 55 meters and 77 meters, and the maximum depth of the anti-seepage wall is 95 meters, which is among the same projects in China. most.

In addition, the hydropower station has also overcome the challenges of building long-span high-head arch dams under complex geological conditions, stabilizing the excavation and support of large underground cavern groups, and developing and manufacturing giant units with a single capacity of one million kilowatts. and a series of world-class problems such as installation and debugging.

Super Technology 1: Low-heat cement concrete has been developed for decades and is used throughout the dam.

The Wudongde Hydropower Station Dam is a concrete double-curved arch dam with an altitude of 718 meters at the bottom and 718 meters above sea level at the top. It is 988 meters above sea level and the highest dam is 270 meters high. However, the thickness of the dam base is only 51 meters. This proportion makes the Wudongde Hydropower Station the thinnest 300-meter arch dam in the world. The slender body has to carry the water storage of a super-large hydropower station with a capacity of tens of millions, which undoubtedly places unprecedented high demands on the quality of concrete pouring.

The total concrete pouring volume of the dam is approximately 2.8 million cubic meters. In such a large volume of concrete pouring, temperature control is crucial, because excessive changes in temperature can cause cracks in the concrete and threaten the safety of the dam. This has always been a worldwide problem in hydropower projects.

Because the hydropower station is located in the hot dry valley of the Jinsha River, the sunshine is strong, and the temperature on the dam construction platform reaches more than 40 degrees during the hottest period. The low-heat cement concrete used in the entire Wudongde Hydropower Station is a pioneering work in the history of dam construction in the world.

Low-heat cement can be called the "antipyretic" for dams. When the atmospheric temperature reaches 30 degrees, the displayed temperature of the concrete can still reach about 7 degrees. This "antipyretic medicine" is the result of decades of painstaking "research and development" by the Three Gorges people. This is the first time that the entire dam body is made of low-heat cement.

Super technology two: cooling artifact embedded thermometer + sprayer + cooling water pipe

According to the construction requirements, the pouring temperature of the dam concrete cannot exceed 18 degrees. In order to ensure that it can survive in high temperature weather To meet the construction requirements, a sprayer was installed on the construction warehouse surface to reduce the ambient temperature of the warehouse surface. Even if the outdoor temperature is in the 30s or 40s, the temperature inside the warehouse can still be controlled at 20-30 degrees.

In order to sense the temperature of all parts of the dam in an all-round way, the dam can sense the temperature of the concrete in real time by embedding thermometers and cooling water pipes in the concrete. Through the intelligent water supply system, the water flow can be automatically adjusted to realize an intelligent concrete cooling process.

Super Technology Three: The "Sky Eye" of the Dam, more than 10,000 grouting holes to prevent water seepage in the dam base mountain body

If temperature control ensures that the dam has hard bones and strong muscles, then Cement slurry is poured into the cracks, and after solidification, the rock cracks and the dam and the mountain are integrated into one, which further strengthens the dam's muscles and bones. This is also vividly called calcium supplementation of the mountain.

The deepest grouting and drainage corridor of the Wudongde Dam crosses the bottom of the dam and extends into the mountains on both sides. In order to prevent the water from the upstream of the dam from seeping into the downstream, some grouting and drainage corridors were drilled on the ground. Curtain hole, the maximum curtain hole depth reaches 110 meters.

It is reported that the total project length of the main curtain is 500,000 meters, with approximately more than 10,000 grouting holes. The entire curtain is connected like a large curtain, firmly blocking the upstream water in the dam Front.

Super Technology Four: Slope Protection Artifact Active Net Spider-Man’s Dedication

The lower reaches of the Jinsha River where the Wudongde Hydropower Station is located is a deep canyon. After long-term rain erosion and exposure to the sun, mountains and slopes are in danger of collapse at any time. It can be said that even a small stone particle can penetrate a steel plate.

In order to eliminate hidden dangers, in the early stage of project construction, the construction team first used spiders to peel off the surface gravel and floating soil on the natural slopes on both sides of the bank, and then used more than 50,000 shallow anchors and more than 4,000 Deep anchor cables secure the mountain. These anchor cables penetrate tens of meters into the mountain, tightly fixing the rocks and the mountain together.

After these are completed, 1 million square meters of active protection net, equivalent to the size of 200 football fields, will be laid to cover the entire slope. In the excavated slope areas, shotcrete must be grouted to fix the entire rock mass, and passive protective nets must be set up at different heights.

Since the establishment of these protective nets, many major dangers have been successfully eliminated. In addition, monitoring sensors are buried in the mountain, a geological disaster monitoring system is established, and it is linked with the hydrometeorological center. Once there is a slight deformation of the slope, the system can give a timely warning.

Super Technology Five: The main underground power plant building is the tallest in the world

The distance between the two mountains at the top of the Wudongde Hydropower Station dam is only more than 300 meters. Due to the small space, in addition to the 270-meter-high dam building, more structures of the Wudongde Hydropower Station are hidden in the mountains and underground. As the main power generation equipment of the hydropower station, the main factory building of the hydraulic turbine unit is located in the mountains on both sides of the dam.

The excavation length of the main factory building of the Wudongde underground power station is 333 meters, the span is 32.5 meters, and the height is 89.8 meters, which is equivalent to a nearly 30-story high-rise building. This height breaks the excavation of the main factory building of the underground power station. height world record.

It is understood that the Wudongde Hydropower Station plans to lower the sluice to store water in July 2020 and put it into operation in December 2021. As a green energy source, after the Wudongde Power Station is completed, it can save about 12.2 million tons of standard coal and reduce the emission of 30.5 million tons of carbon dioxide and 104,000 tons of sulfur dioxide.

During the construction period of the hydropower station, an average of about 70,000 new jobs can be added each year. After the power generation is completed, local fiscal revenue will increase by about 1.35 billion yuan each year.