One drop of water can generate electricity for six times, and the Yangtze River Golden Waterway has become the world’s largest clean energy corridor.
The mighty Yangtze River, which gathers great rivers and passes through the long gorge, is rich in resources such as hydropower, shipping and fresh water.
Six large hydropower stations, Wudongde, Baihetan, Xiluodu, Xiangjiaba, Three Gorges and Gezhouba, are arranged from top to bottom along the main stream of the Yangtze River, forming the world’s largest clean energy corridor: spanning more than 1,800 kilometers, with a water level drop of over 900 meters, a total of 110 hydro-generator sets are running in succession, and the vast river brings rolling green electricity.
Not long ago, the industrial Internet platform was deployed in six cascade hydropower stations, which indicated that the "industrial brain", the world’s largest clean energy corridor, was basically completed, and the operation efficiency, safety and reliability of hydropower stations were greatly improved.
The cumulative power generation of six cascade hydropower stations has exceeded 3.5 trillion kWh, which is equivalent to saving over 1 billion tons of standard coal and reducing carbon dioxide emissions by over 2.8 billion tons. At the same time, cascade reservoirs cooperate with each other, and the benefits of smooth shipping, water resources protection and ecological protection are comprehensively released.
Figure ①: wudongde hydropower station. Photo courtesy of Three Gorges Group
Figure ②: Baihetan Hydropower Station. Xinhua News Agency reporter Chen Xinbo photo
Figure ③: Xiluodu Hydropower Station. Photo by Zeng Sandong (image China)
Figure ④: Xiangjiaba Hydropower Station. Wu Xinshe (image China)
Figure ⑤: Three Gorges Hydropower Station. Photo by Zheng Kun (image China)
Figure ⑥: Gezhouba Water Control Project. Photo by Wang Geng (image China)
Source: Three Gorges Group
Total installed capacity of 71.695 million kilowatts
"One drop of water sends 6 times of electricity", and the joint debugging of six reservoirs makes the "green engine" stronger.
Baihetan Hydropower Station between deep canyons, the concrete hyperbolic arch dam with the maximum dam height of 289 meters is included in the Pentium River. The water flowing down from a height of more than 200 meters drives the runner of the hydro-generator set to rotate, and the unit can generate about 150 kWh of electricity every time it rotates.
Sixteen million-kilowatt hydro-generator sets of Baihetan Hydropower Station are running at full capacity. Wang Bin, deputy director of the operation department of Baihetan Power Plant of Yangtze River Power, said: "Operators are on duty 24 hours a day, sensors collect data in real time, and the system will automatically give an early warning once the operation indicators are abnormal."
"The generator set is like a gyro that rotates by water, converting kinetic energy into electrical energy." Kang Yonglin, former deputy director of Baihetan Engineering Construction Department of China Three Gorges Group Co., Ltd. (hereinafter referred to as "Three Gorges Group"), said that at the speed of 111 revolutions per minute, the coins standing on it did not move, and the swing of each bearing was less than 0.1 mm during operation … … "The key technologies such as the overall arrangement of units, electromagnetic design, and manufacturing of major components have successively achieved important innovations, which have witnessed the leading position of China Hydropower in the fields of equipment manufacturing, design and installation."
In December 2022, Baihetan Hydropower Station realized that all units were put into operation to generate electricity. Looking back from Baihetan, this clean energy corridor has witnessed the breakthroughs of hydropower technology in China.
Gezhouba, which was completed in the 1980s, has a maximum capacity of 170,000 kilowatts per hydro-generator unit. As the largest water control project in the world, the Three Gorges Hydropower Station has overcome the design and manufacturing technology of 700,000 MW units. Subsequently, in Xiluodu, Xiangjiaba and wudongde hydropower station, the single unit capacity of hydro-generator sets has exceeded 770,000, 800,000 and 850,000 kilowatts.
Upgrading is not a simple addition, and the difficulty coefficient of R&D technology increases geometrically every time. The capacity of a single machine has reached million kilowatts, which is inseparable from the application of a series of new technologies and materials, and the whole industrial chain has been upgraded, such as hydraulic design, generator ventilation and overall design of units. "The million-kilowatt unit has greater head impact, faster rotating speed and higher bearing pressure. The Three Gorges Group has taken the lead in large-scale steel enterprises and developed 800 MPa-class high-strength spiral case steel plates, getting rid of the situation of long-term dependence on imports." Li Haijun, deputy director of the Electromechanical Technology Center of Three Gorges Group, gave an example.
The total installed capacity of the six cascade hydropower stations is 71.695 million kilowatts, which is equivalent to the installed capacity of the three Gorges hydropower stations, and the energy supply is constantly enhanced, and five of them have become the backbone power stations of "West-to-East Power Transmission".
"The Yangtze River water passes through six hydropower stations in turn, which is equivalent to one drop of water generating six times of electricity." Kang Yonglin calculated a detailed account: 1 cubic meter of water can produce 0.25 kWh of green electricity through the Three Gorges Hydropower Station; The power generation multiplier effect is realized by the joint dispatching of six reservoirs, and the power generation can reach 2 kWh, and the efficiency is increased to 8 times.
"The operation and scheduling of giant power stations in the basin involves ‘ Water, machinery and electricity ’ Multiple links, huge scale, changeable time and space, cross-regional and cross-network, complex structure. Cascade hydropower stations bear both peak load and base load, which puts forward higher requirements for long-term safe and stable operation of hydropower. " Tang Zhengyang, deputy director of the Yangtze Power Science and Technology Research Center, said. The industrial Internet platform deeply empowers all business scenarios such as intelligent operation and maintenance, intelligent maintenance, intelligent dispatching and intelligent decision-making, comprehensively improves the intelligent operation and maintenance level of equipment, and helps the digital construction of hydropower stations.
768 km deepwater reservoir channel
Release the "golden benefit of golden waterway" to help the Yangtze River freight volume stay ahead.
The Three Gorges Dam and the double-track five-level ship lock are located on the left bank. In 2023, the safe operation of shiplocks exceeded 11,000 locks and the number of ships passing exceeded 42,000 — — How to operate safely and efficiently when you open the miter gate of about 900 tons for tens of thousands of times and climb the 113-meter water level difference with a thousand-ton ship?
"The Three Gorges Ship Lock is the largest inland ship lock in the world with the largest number of consecutive stages, the highest water head and the most complicated operating conditions. In operation, we have established mechanisms to ensure smooth shipping." Yang Hua, deputy director of the hub management department of the basin hub operation management center of the Three Gorges Group, said that in order to ensure the safety and reliability of all kinds of construction equipment, the Three Gorges ship lock will be regularly suspended for maintenance. On April 5, 2024, the planned suspension maintenance of the North Line Shiplock of the Three Gorges Project was successfully completed. This is the suspension maintenance with the longest construction period, the heaviest task and the most difficult process connection and coordination since the planned suspension maintenance began in 2012. With the participation of more than 800 people from 16 companies, the upgrading of the industrial control system of the Three Gorges Ship Lock, the overhaul of 12 miter gates and 12 reverse arc gates, and the replacement of 9 sets of oil cylinders were mainly completed within 45 days, which further improved the safety and reliability of the ship lock operation.
When a ship crosses the Three Gorges, it can not only "climb the stairs" but also "take the elevator". On the right side of the lock is the Three Gorges ship lift. According to Yang Hua, the ship-carrying compartment with a height of 10 meters and a water depth of 3.5 meters can accommodate a 3,000-ton ship, and it can be lifted to the height of nearly 40 floors in just 10 minutes. From January to April this year, the cargo volume of the Three Gorges shiplock exceeded 41.4 million tons, the ship lift operated safely for 1,685 times, and the cargo volume of the ship passing exceeded 1.96 million tons, up by 127.73% year-on-year.
Xiangjiaba ship lift is the second giant ship lift built in China after the Three Gorges ship lift, and the cargo volume in 2023 increased by 15.51% compared with the previous year. Since the navigation of Gezhouba Shiplock for more than 40 years, the daily average number of locks has increased from 8 to 49. According to the relevant person in charge of the Operation and Management Center of the Three Gorges Group Basin Hub, the Three Gorges, Xiangjiaba and Gezhouba water control hubs have promoted the Yangtze River shipping and economic development along the Yangtze River, helping the Yangtze River freight volume to continue to rank first in the world’s inland rivers.
Six cascade hydropower stations have formed a 768-kilometer deep-water reservoir channel, and the navigation conditions of the Yangtze River have improved steadily.
A section of rapids has become a water passage. After the completion of the Three Gorges Project, the maintenance depth of the waterway from Chongqing to Yichang has increased from 2.9 meters to 3.5 meters to 4.5 meters, and the tonnage of ships has increased from 1,000 tons to 5,000 tons. 109 beach hazards, 34 one-way controlled river sections and 12 sections that need to be stranded on the beach between the dam site and Chongqing have been eliminated, and "the river has never sailed at night since ancient times" has become history.
Ports go from small to large and then to strong. On the Yangtze River waterway in Chongqing, a number of deep-water wharves with a tonnage of more than 5,000 tons have been formed. Ports in the Three Gorges reservoir area, such as Yichang in Hubei, Fuling in Chongqing and Wanzhou, are booming. The advantages of low energy consumption, large transport capacity and low cost of the Yangtze River water transport have been fully exerted, further releasing the "golden benefits of the golden waterway".
The total storage capacity is 91.9 billion cubic meters
Form a strategic freshwater resource pool to provide support for water supply, water replenishment and ecological dispatching.
The Yangtze River Basin is a strategic water source for water resources allocation in China, with an average annual water resource of 995.9 billion cubic meters, accounting for about 36% of the country. Among them, this clean energy corridor forms a cascade reservoir group and a strategic freshwater resource pool with a total storage capacity of 91.9 billion cubic meters.
The benefit of water supply and water replenishment is remarkable. Li Peng, deputy chief engineer of the Three Gorges Cascade Dispatching of Yangtze Power, said: "We have rationally coordinated the dispatching plan and energy supply requirements, which has provided a guarantee for the comprehensive benefits of water supply, power generation, shipping and ecology."
Ecological dispatching continued. Fish resources are an important indicator to measure the health of rivers. The orderly increase of the discharge of reservoirs and the slow rise of the water level in river sections can create conditions for natural reproduction of fish. 2023 is the second year that Wudongde, Baihetan, Xiluodu, Xiangjiaba and Three Gorges Reservoir are all included in the scope of ecological dispatching. Relevant units have successively coordinated and organized 12 ecological dispatching experiments in three categories, namely, water temperature adjustment of stratified water intake at the stoplog gate, promotion of the reproduction of fish with sticky eggs by "base load power generation" and promotion of the reproduction of fish with drifting eggs. The world’s largest clean energy corridor has become an ecological protection corridor.
The scope of ecological regulation is constantly expanding. According to the person in charge of the Yangtze River Water Conservancy Commission of the Ministry of Water Resources, at present, the dispatching objects have expanded from promoting fish reproduction to regulating the water temperature of stratified water intake, preventing water bloom, discharging sand and reducing siltation in the reservoir area, and inhibiting excessive reproduction of submerged plants. The dispatching reservoir has expanded from the Three Gorges Reservoir to the cascade reservoirs in Jinsha River, Yalong River and Hanjiang River basins, which has effectively promoted the water ecological protection and restoration in the Yangtze River basin.
The relevant person in charge of the Three Gorges Group said that the comprehensive benefits of the world’s largest clean energy corridor will provide strong support for flood control safety, shipping safety, energy safety and ecological safety in the Yangtze River basin at a higher level, in a wider field and in a wider scope, and will continue to help the Yangtze River Economic Belt develop with high quality.
Published in People’s Daily, 2nd edition, May 15th, 2024.
People’s Daily reporter Wang Hao