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Speaking of the famous water conservancy projects on the mainland, I believe that many people should blurt out that the Three Gorges Hydropower Station should be the Three Gorges Hydropower Station, but do you know that the Baihetan Hydropower Station is not as large as the Three Gorges, but it has won many world firsts, and is known as the "Mount Everest" of the hydropower industry.
How good is Baihetan Hydropower Station?
The Baihetan Hydropower Station cost 180 billion yuan and has only been in use for two years, with a cumulative power generation capacity of more than 100 billion kilowatts, equivalent to the electricity consumption of 148 million people in a day, and single-handedly meeting one-tenth of China's electricity demand.
But despite this, the Baihetan hydropower station is still known as the second largest hydropower station in the world, after the Three Gorges hydropower station. Because its overall scale is not as large as that of the Three Gorges, but in some respects, the Baihetan Hydropower Station is a step above the Three Gorges technology, such as higher efficiency and energy density.
The Three Gorges Hydropower Station has an installed capacity of 22.5 million kilowatts, an average annual flow of 450 billion cubic meters, and an annual power generation of 90 billion kWh, while the Baihetan Hydropower Station has an installed capacity of only 16 million kilowatts, an average annual flow of 130 billion cubic meters, and an annual power generation of 62.4 billion kWh. In other words, with the same amount of water, the Baihetan Hydropower Station generates 2.4 times more electricity than the Three Gorges.
Why is the power generation efficiency of the Baihetan Hydropower Station so high? The first thing that many people think of is the problem of the water level drop. Indeed, Baihetan is located at the junction of steps, sandwiched by two mountains, the river valley is narrow, and the water flow difference is large. The Three Gorges Hydropower Station is located in the Hanjiang River Plain, with a wide river surface and a large reservoir capacity, but the water level difference is relatively small. In terms of the natural hydropower resources of the two, Baihetan is indeed slightly superior.
However, in fact, there are not a few hydropower stations on the mainland that have such natural advantages, so why can Baihetan stand out and become a rich and colorful stroke in the history of water conservancy projects on the mainland? In the final analysis, it is still necessary to firmly believe that advanced technology is the highest productive force.
Baihetan Hydropower Station is equipped with the world's largest capacity of million-kilowatt hydro-generator units, with a total installed capacity of 16 million kilowatts, the world's largest single power generation power, one second of power generation is enough for an ordinary family for two whole months, equivalent to burning 172 catties of standard coal for power generation.
Baihetan Hydropower Station has overcome numerous technical problems
Before the advent of the Baihetan Hydropower Station, the mainland's domestically produced generator sets were already the world's leading 850,000 kilowatts, while the Baihetan generator sets were equivalent to standing on the top of the mountain to climb higher peaks, reaching 1 million kilowatts, so its structure is completely different from ordinary hydro generators.
The length and size of the runner blades of ordinary generators are exactly the same, while the hydro generator in Baihetan is composed of long and short blades, which increases the total area and ensures the smooth flow of water at the outlet, and the efficiency of the turbine that is almost impossible to improve is 96.7%, almost without wasting a drop of water.
The biggest challenge in manufacturing is achieving the uniformity of the hydrogenerator. The turbine generator rotates 111 times per minute when working, and at such a high speed, if the weight of one blade is slightly different, the rotation will be deviated and displaced. Not to mention the impact on power generation efficiency, in the long run, it will also shorten the service life of the turbine.
Therefore, the error of the size of these runners should be controlled within a few tenths of a millimeter, and the final generator produced will not exceed 0.03 mm when rotating at full speed, and the diameter of a hair is not large, even if a few coins are standing next to it, it can be immovable.
Not only the generator set, as the most technically difficult hydropower station at present, Baihetan Hydropower Station has entered the "no man's land" of hydropower technology in the world for a number of indicators.
The amount of work involved in the preparation for the construction of the dam alone is staggering. The mountains on both sides of Baihetan are not completely symmetrical. The slope on the right side is steeper than on the left, so the water pressure on the left and right sides of the dam is also asymmetrical, and if the pressure on one side is too high, it is easy to cause a collapse accident.
In order to solve this problem, the construction team decided to pour a cushion on the left bank before building the dam, so that the two sides of the valley are as symmetrical as possible, and then drive the hollow grouting anchor pipe into the hillside, which is equivalent to adding a steel skeleton to the hillside, increasing the firmness of the mountain and preventing landslides.
When building a dam, concrete is generally poured, but because during the pouring process, the concrete will release a large amount of heat when exposed to water, solidify and then cool, so that the rapid thermal expansion and contraction can easily cause fine cracks in the concrete. In addition, the temperature of the river valley in Baihetan is high and the wind is strong, which will take away more moisture from the concrete surface, making cracks more likely to occur.
But for a water conservancy project of Baihetan's size, the pressure on the impoundment of water is equivalent to the weight of 100,000 locomotives, like an elephant standing on the cover of a fingernail. The risk posed by any crack in this case is immeasurable.
In order to avoid this risk, the engineers once again "braved the no-man's land" and developed low-heat concrete directly from scratch. At the same time, a temperature control system is installed, once the temperature is detected in the pouring process is slightly abnormal, immediately adjust the speed of the master or take physical cooling, the whole pouring process from the beginning to solidification, the temperature is kept around 7 °C, so that the dam of 8 million square meters of concrete pouring has no crack from head to toe.
Why does the Baihetan Hydropower Station have to be repaired?
Since the construction of the Baihetan Hydropower Station is so difficult, why do we still need to build it? Aren't we already having the world's largest Three Gorges Hydropower Station?
But in fact, the Three Gorges Hydropower Station cannot replace other hydropower stations. This is not simply a matter of total power generation, the Yangtze River basin has a vast area and a wide range of areas, and it is necessary to build multiple cascade hydropower stations. The Baihetan Hydropower Station is located in Liangshan Prefecture, Sichuan Province, far from the Three Gorges Dam. They are responsible for supplying electricity to the inhabitants of the southwest region and the Han River Plain, respectively.
In addition to power generation, mainland hydropower stations often have a variety of functions such as flood control and shipping, and the Baihetan Hydropower Station is the second cascade power station developed in the main stream of the lower reaches of the Jinsha River, which plays an important role in the comprehensive benefits of shipping and flood control on the Yangtze River.
More importantly, the Baihetan Hydropower Station is also an important part of the mainland's "West-to-East Power Transmission" project.
The "West-to-East Power Transmission" project is divided into three main channels, of which the central channel is from Chongqing, Sichuan Province to East and South China, and is mainly dominated by hydropower from the Three Gorges and the main tributaries of the Jinsha River. The Baihetan Hydropower Station is an important source of the Jiangsu-Zhejiang transmission line project.
Water conservancy projects along the entire Yangtze River constitute a large corridor for clean energy transmission, and the first units of the Baihetan Hydropower Station have been put into operation for power generation, marking the completion of the world's largest clean energy corridor.
Along this energy engineering route, every drop of water in the Yangtze River has become a proper "worker", and from upstream to downstream, it will pass through the six giant hydropower stations of Wudongde, Baihetan, Wudongde, Xiluodu, Xiangjiaba, Three Gorges, and Gezhouba, which means that every drop of water will generate electricity six times.
It is conceivable that if hydropower stations in the middle and upper reaches of the Jinsha River are also built in the future, the water resources of the Yangtze River will be more fully utilized! These six giant hydropower stations will be jointly dispatched, and the average annual power generation capacity will reach an astonishing 300 billion kilowatt hours, all of which are clean hydropower energy. It can save about 90.45 million tons of standard coal and reduce carbon dioxide emissions by about 248.4 million tons every year. Looking at the world, China is the only country that can build such a large-scale system project.
In the journey of building Baihetan Hydropower Station, we continue to contend, innovate and develop, and strive to light up the lights of thousands of homes. This is the posture of the rise of a great power and heavy weapon, and it is also the responsibility and mission entrusted to us by the times. The river is rushing and mighty, and the Baihetan Hydropower Station is like a rising bright pearl, shining with the most dazzling brilliance in the history of hydropower construction in the world.