Flooding in central China in July this year put millions of people in the country at risk of flooding. The world's largest dam and hydroelectric power station, called Three Gorges (Sanxia, Sanxia). The flood was so strong that the Three Gorges Dam set an absolute record, working at its maximum capacity for several days and releasing about 70 thousand cubic meters of water per second. Considering the scale of this gigantic dam, one can only imagine how catastrophic the consequences of its destruction could be.
Three Gorges in China - The largest dam in the world
Fortunately, everything worked out and the dam withstood the strong pressure of water. But the authorities still had to promptly evacuate more than a million people from the surrounding areas. Flood losses in the surrounding areas upstream amounted to several million yuan. You can appreciate the scale of what is happening by looking at these photos of the Three Gorges Dam during the flood:
Let me remind you that the Three Gorges hydroelectric power station (HPP) was built quite recently. Only this year were all the work on its construction completed. The construction itself began back in 1992. The dam is located in China on the Yangtze River and is the largest power plant in the world. The dam is located near Sandouping in Yichang City, Hubei Province. The pressure structures of the hydroelectric power station form the largest reservoir, during the creation of which 27,820 hectares of cultivated land were flooded and about 1.2 million people were resettled. The cities of Wanxian and Wushan went under water.
gravitational
spillway
ship lift 1 chamber 120×18×3.5 m
Three Gorges Hydroelectric Power Station
Three Gorges Dam (left) and Gezhouba Dam (right) from space
As of 2018, the Three Gorges is the largest mass construction of the world. His concrete the dam, unlike Itaipu, is solid and weighs more than 65.5 million tons. Based on the total cost of the Three Gorges work, it is estimated at 203 billion, or about 30.5 billion, and within the framework of the project turning of Chinese rivers is the fifth most expensive investment project in the world . Formed by a dam reservoir contains 39.3 km³ of water and is the 27th largest in the world (English). To fill it, 1.3 million people were resettled from coastal areas, which became the largest resettlement in history for the construction of artificial structures. The costs of relocating people amounted to about a third of the entire construction budget.
In addition to producing environmentally friendly electricity(and, as a consequence, reducing emissions greenhouse gases from TPP), the dam protects downstream cities from destructive floods Yangtze. Increasing the depth of the river upstream also improved conditions shipping; equipped with five gateways waterworks increased local freight turnover ten times. A project of this scale also has negative consequences: flooding fertile lands in areas upstream, sediment retention silt dam (and reduction of natural fertilization lands in the lower regions at the previous annual spills Yangtze), flooding archaeological facilities, increased risk landslides, decrease biological diversity. When a dam breaks, more than 360 million people are in the flood zone, so the facility itself and the surrounding waters are patrolled by the PRC army using helicopters , airships , armored vehicles And robots For demining bombs.
Story
The idea of building a large dam on the Yangtze River was originally expressed by the Prime Minister Kuomintang Sun Yat-sen in the work “International Development of China” in 1919. He stated that in the area Three Gorges the dam is capable of generating power at 30 million Horse power (22GW) . In 1932 the government Republic of China, led by Chiang Kai-shek, began preliminary work on plans for the dam. In 1939 during Sino-Japanese War Japanese military forces occupied the district Yichang and explored the area. The Japanese dam project was completed and only victory over united China to begin its implementation [ ] .
Composition of hydroelectric power stations
Composition of hydroelectric power station structures:
- gravity concrete dam 2309 m long and 181 m high;
- left bank dam hydroelectric power station building with 14 hydraulic units ;
- right bank dam hydroelectric power station building with 12 hydraulic units;
- right bank underground hydroelectric power station building with 6 hydraulic units;
- two-thread five-stage shipping lock(mainly intended for cargo ships, lock passage time is about 4 hours, chamber dimensions are 280x35x5 m);
- ship lift(mainly intended for passenger ships, carrying capacity 3,000 tons, ascent/lowering time 10 minutes, passage time 30 minutes)
The dam is 2309 m long and 181 m high from the rock base, made of concrete And become. The project used 27.2 million m³ of concrete (a record amount for a single project), 463 thousand tons of steel and moved about 102.6 million m³ of earth.
Three buildings of the hydroelectric power station house 32 radial-axial hydraulic units with a capacity of 700 MW each with a design head of 80.6 m. Two generators with a capacity of 50 MW each were also put into operation for the station’s own needs. Since the addition of the underground turbine room in 2012, the amount of electricity generated per year has become more dependent on the size of the flood on Yangtze, the operation of which is allowed by additional electric generators.
Pressure structures of hydroelectric power stations form a large reservoir with an area of 1045 km², a useful capacity of 22 km³. During its creation, 27,820 hectares of cultivated land were flooded, cities went under water Wanxian And Wushan. The maximum permissible height of the top pool above sea level(NSL) equal to 175 m was first achieved in 2010. The reservoir can be discharged up to 145 m. The height of the tailwater above sea level is 66 m. Thus, the pressure level throughout the year varies from 79 m to 109 m, the maximum is reached in the summer season monsoon. Waterworks equipped spillway capacity 116,000 m³/sec.
Project financing
The government initially estimated the cost of the Three Gorges project at ¥180 billion ($26.9 billion). By the end of 2008, expenditures reached ¥148.365 billion, of which ¥64.613 billion was spent on construction, ¥68.557 billion on benefits for affected residents and their relocation, and ¥15.195 billion on loan payments. In 2009, it was determined that the cost of the dam would be recouped when it produced 1,000 TWh electricity, which at electricity prices in China is ¥250 billion. According to calculations, the payback period was ten years after the start full work dams, however, the Three Gorges hydroelectric power station fully paid for itself by December 20, 2013 - 4 years after the launch of the first turbines and a year after the official commissioning.
The sources of financing for the dam were: the Three Gorges Construction Fund, income from hydroelectric power station " Gezhouba", loans from Chinese Development Bank, loans from Chinese and foreign commercial banks, Corporate bonds, the income received from the dam itself before and after its full commissioning. Additional fees were also established: in each province receiving electricity from the Three Gorges hydroelectric power station, a surcharge of 7 ¥ per MWh was established, in all other provinces with the exception of Tibet Autonomous Region, the premium was ¥4 per MWh.
Economic significance
The Three Gorges hydroelectric power station is of great importance for the Chinese economy, covering the annual growth in electricity consumption. The power plant, together with the Gezhouba hydroelectric station in the downstream, became the center of China's unified energy system. It was initially expected that the hydroelectric power station would cover 10% of China's electricity needs. However, over 20 years of construction, electricity consumption grew at a faster pace, and in 2012, the hydroelectric station generated only 1.7% of all Chinese electricity (98.1 out of 4692.8 TWh).
The dam regulates the water regime of the Yangtze, where destructive floods have occurred more than 200 times over the past 2000 years. In the 20th century, catastrophic river floods caused the death of about half a million people. In 1991, damage from the violence of the water disaster amounted to 250 billion ¥ (equivalent to the cost of building a hydroelectric power station). However, the flood of 2010 did not lead to casualties or significant damage. Thus, the spillway and the dam itself successfully cope with their assigned functions.
Electricity production and distribution
Generators
The generators were manufactured according to two design options by two joint groups of enterprises: one of them - Alstom , ABB Group, Kvaerner (English) and the Chinese company Haerbin Motor; another - Voith , General Electric , Siemens and the Chinese company Oriental Motor. A technology cooperation agreement between the groups was signed along with the contract. Most generators have water cooling. Some newer models have - air, which has the advantage of being easy to design, manufacture, and maintain.
Electricity generation
In July 2008, monthly hydroelectric power production exceeded the 10 TWh (10.3 TWh) mark for the first time. On June 30, 2009, after the Yangtze flow exceeded 24,000 m³/s, all 28 generators were turned on, producing only 16,100 MW, because the installed capacity of the generators was not yet sufficient to handle the increased flow during the flood period. During the floods in August 2009, the hydroelectric power plant reached its peak output for the first time of 18,200 MW for a short period.
During the dry season from November to May, the hydroelectric power generation capacity is limited by the volume of river flow, as can be seen in the diagrams on the right. If there is sufficient flow, the output power is limited by the capabilities of the generators. The maximum power curves were calculated based on the average flow rate, assuming a water level of 175 m and a gross unit efficiency of 90.15%. Actual power in 2008 was derived from monthly electricity sent to the grid.
The estimated maximum water level of 175 m was first reached on October 26, 2010, during the same year an estimated annual production of 84.7 TWh was realized. In 2012, 32 power units of hydroelectric power stations produced a world record power of 98.1 TWh of electricity, which amounted to 14% of the output of all hydroelectric power stations in China. By August 2011, the hydroelectric power station produced 500 TWh of electricity.
| Year | Number of power units | TWh | |
|---|---|---|---|
| 2003 | 6 | 8.607 | |
| 2004 | 11 | 39.155 | |
| 2005 | 14 | 49.090 | |
| 2006 | 14 | 49.250 | |
| 2007 | 21 | 61.600 | |
| 2008 | 26 | 80.812 | |
| 2009 | 26 | 79.470 | |
| 2010 | 26 | 84.370 | |
| 2011 | 29 | 78.290 | |
| 2012 | 32 | 98.100 | |
| 2013 | 32 | 83.270 | |
| 2014 | 32 | 98.800 | |
| 2015 | 32 | 87.000 | |
| 2016 | 32 | 93.500 | |
| 2017 | 32 | 97.600 | |
| 2018 | 32 | >100.00 [ ] |
Electricity distribution
Until July 2008, state-owned companies State Grid Corporation of China and China Southern Power Grid (English) hydroelectric power plants paid a flat rate of 250 ¥ per MWh (2.5 rubles per kWh). Currently, provincial rates range from ¥228.7 to ¥401.8 per MWh. High-paying consumers, e.g. Shanghai, receive priority in the distribution of electricity.
To transmit electricity from hydroelectric power stations to consumers, 9,484 km of high-voltage networks were built power lines, including 6519 km - alternating current voltage of 500 kV and 2965 km - DC lines voltage ±500 kV and higher. Total installed power of transformers at voltage alternating current is 22.75 GV·A, and for a direct current system - 18 GW. In total, 15 high-voltage lines radiate from the hydroelectric power station to 10 different provinces of China. The construction of the entire transformer and transmission power network from the hydroelectric power station cost ¥34.387 billion. Its construction was completed in December 2007 - a year ahead of schedule.
Navigation across the dam
Gateways
There are two lines near the dam gateways (30°50′12″ n. w. 111°01′10″ E. d. HGIOL). Each of them consists of five stages and takes approximately 4 hours to complete. The locks allow ships with a displacement of no more than ten thousand tons to pass through. The length of the lock chambers is 280 m, width - 35 m, depth - 5 m. This is 30 m longer than on the locks St. Lawrence Seaway, but is twice as deep. Before the construction of the dam, the maximum cargo turnover at the Three Gorges site was 18.0 million tons per year. From 2004 to 2007, the turnover through the locks amounted to a total of 198 million tons. The river's capacity has increased sixfold, while the cost of transportation has decreased by 25%. It is expected that the throughput of the gateways will reach 100 million tons per year.
Sluices are a type of tubeless sluice. The gates are a very vulnerable hinged structure; their failure will lead to disruption of the functioning of the entire thread of the gateway. The presence of two threads, separately for lifting and lowering, ensures more efficient operation compared to the option when one thread serves alternately for raising and lowering ships.
Boat lifts
In addition to the locks, the waterworks is equipped ship lift for ships with a displacement of up to 3,000 tons (the original design provided for a lift with a lifting capacity of 11,500 tons). The lift height varies depending on the levels of the upper and lower pools, maximum height- 113 m, and the size of the lifting chamber is 120 × 18 × 3.5 m. After commissioning, the ship lift will move ships in 30-40 minutes, compared to 3-4 hours if they moved through locks. During its design and construction, the main difficulty was the need to ensure operation in conditions of significant changes in water levels. It is necessary to ensure the operation of the ship lift in conditions where the water level can be within 12 m on the downstream side and 30 m on the upstream side.
The first tests of the ship lift took place on July 15 2016, during which the cargo ship was lifted into the upper pool, the lifting time was 8 minutes. . In October, the world's largest ship elevator at the world's largest power plant went into operation.
Rail ship lift
There are plans to build rail tracks to transport ships across the dam. To do this, they are going to lay short rail tracks on both sides of the river. The 88-kilometer northern rail section will run from the Taipingqi port area ( Taipingxi) on the north side of the Yangtze, up from the dam across railway station Yichang East to Baiyan Tianqiahe Port Area in Baiyan City. The 95-kilometer southern section will run from Maoping (on the upstream side of the dam) through Yichang South railway station to Zhitseng.
At the end of 2012, preparatory work began on laying these railway tracks.
Environmental consequences
Considering the fact that in China, 366 g are burned to generate 1 kWh of electricity coal It is expected that the commissioning of the power plant will lead to a reduction in coal consumption by 31 million tons per year, due to which 100 million tons will not be emitted into the atmosphere greenhouse gases, millions of tons of dust, 1 million tons of sulfur dioxide, 370 thousand tons of nitrogen oxide, etc. It was also announced that increasing the level of the Yangtze due to the creation of a reservoir will allow much larger vessels to pass along the river, which will also reduce emissions of combustion products into the atmosphere organic fuel.
At the same time, many scientists point out the possible negative consequences of the construction of hydroelectric power stations. Before the construction of the dam, the Yangtze and its tributaries, eroding the banks, carried out millions of tons annually sediment. Due to the damming of the channel, this number will be significantly reduced, which is thought to lead to greater vulnerability of downstream areas to flooding, as well as changes in species diversity. It is also noted that the construction of the dam cannot but harm a number of biological species inhabiting the river and surrounding areas. In particular, significant damage to the population of the almost extinct Siberian Crane may cause flooding of wetlands where this rare bird winters. It is expected that changes in temperature and water conditions due to the construction of the Three Gorges will inevitably affect a number of fish species living in the Yangtze, in particular the family sturgeon. Concerning Chinese river dolphin, which most likely became extinct by the beginning of the construction of the hydroelectric power station, it is believed that the construction of the dam will finally put an end to the survival of this species.
If the dam breaks, about 360 million people could be at risk of falling into the flood zone.
Construction chronology
Gallery
Notes
- Hydroelectric power station "Sanxia" ("Three Gorges") or the Great Wall of China on the Yangtze River
- (English) (undefined) (inaccessible link - story) . Hydro World
- Register of dams - Classification by installed capacity of hydroelectric power plants
- China's Three Gorges sets new production record (undefined) (inaccessible link - story) . Hydro World(January 10, 2013). Retrieved January 10, 2013.
- Top 10 Heaviest Concrete Structures in the World
- 10 of the World's Largest Construction Projects
- Three Gorges Dam protected by armed troops
- 中国国民党、亲民党、新党访问团相继参观三峡工程
- John Lucian Savage Biography
- 1992年4月3日全国人大批准三峡工程 (undefined) (unavailable link). Archived from the original on September 27, 2011.
- Water level at Three Gorges Project raised to full capacity (undefined) (unavailable link). Archived October 29, 2010.
- 世界最大"升船电梯"三峡大坝试验成功
- Equivalent to building 63 Eiffel Towers.
- Exploring Chinese History: The Three Gordes Dam Project
- V. Ovchinnikov. China has successfully completed the “construction of the century” on the Yangtze // “ Russian newspaper» No. 244 (4801) dated November 27, 2008.
- Beyond Three Gorges in China 10 January 2007 (undefined) (unavailable link). Archived from the original on June 14, 2011.
- 三峡工程今年将竣工验收 包括枢纽工程等8个专项 (undefined) (unavailable link). Archived from the original on February 8, 2009.
- 官方：三峡工程收回投资成本
- 建三峡工程需要多少钱 (undefined) (unavailable link). Archived from the original on April 7, 2007.
- 三峡输变电工程综述 (undefined) (unavailable link). Archived from the original on April 29, 2007.
- 能源局:2011年全社会用电量累计达46928亿千瓦时
- 五、我水轮发电机组已具备完全自主设计制造能力 (undefined) (unavailable link). Archived from the original on December 7, 2008.
- 三峡工程及其水电机组概况 (undefined) (unavailable link). Archived from the original on December 7, 2008.
- 三峡电站月发电量首过百亿千瓦时 (undefined) (unavailable link). Archived from the original on December 7, 2008.
- 三峡工程左右岸电站26台机组全部投入商业运行(undefined) (unavailable link). China Three Gorges Project Corporation (October 30, 2008). Retrieved December 6, 2008. Archived February 9, 2009.
- 三峡工程发挥防洪作用三峡电站首次达到额定出力1820万千瓦 (undefined) (unavailable link). Archived from the original on September 8, 2011.
- 主要水电厂来水和运行情况 (undefined) (unavailable link). Archived January 30, 2009.
- 国调直调信息系统 (undefined) (unavailable link).
This is the greatest structure built on the Yangtze River in China, the largest hydroelectric power station in the world! The scale is truly amazing: the reservoir covers an area of about 1,045 km², the design capacity is 22.5 GW, i.e. 22.4 million kW.
The construction of such a grandiose facility began back in 1992 and was fully completed only in July 2012. During this time, 13 cities, 140 villages, and about 1,300 villages went under water. During the construction of the Three Gorges hydroelectric power station, 1.3 million people had to leave their homes, and approximately 1,300 archaeological sites disappeared under water forever.
More than $30 billion was spent on the construction of the world's largest hydroelectric power station, the Three Gorges Dam in China. The idea of creating such a hydroelectric power station is explained not only by the generation of huge amounts of electricity, but is also intended to prevent constant flooding settlements, which are located next to the Yangtze River. For example, in 1998, about 4,000 people died as a result of flooding in the Yangtze River floodplain, and 14 million people were left homeless.
True, environmentalists also assume negative consequences: a possible disruption of the natural balance, which can lead to droughts or all sorts of anomalous phenomena in the area.
The Sanxia HPP itself consists of several, or rather 3 parts: a hydroelectric station on the left and right banks of the dam, as well as an underground hydroelectric station. There are 32 hydro turbine power units located here, each with a capacity of 700,000 kW. As a result of the construction of the dam, the reservoir extends along the Yangtze River for 360 miles.
Another plus of the construction of the Three Gorges hydroelectric power station in China: previously, the river carried approximately 265 gallons of all kinds of waste and sewage directly into the ocean, but now they settle and are filtered. But, again, employees of National Sun Yat-sen University and National Central University (Taiwan) assume that due to the huge artificial lake, the surrounding soils may become depleted and dry out, because contamination of the base of the dam with organic matter, silt and lack of oxygen for its decomposition can lead to the release of huge amounts of nitrous oxide and methane into the atmosphere.
For the passage of ships at the Three Gorges Hydroelectric Station, two strings of locks were built, each of which has 5 steps, and the passage time is approximately 4 hours!
Undoubtedly, the largest hydroelectric complex in the world, “Sanxia” or the Three Gorges in China, attracts many tourists here. Co observation deck, which is located at an altitude of 185 m above sea level, you will see an amazing sight!
The Three Gorges is not just the largest hydroelectric power station in the world, but also a national Chinese landmark, attracting many tourists from all over the world. The largest hydraulic structure, located at the mouth of the Yangtze River, was built to perform three main functions - production electrical energy, flood control, and to improve navigation conditions. Construction of this facility began in 1994, and nine years later the station began generating its first electricity. In July 2012, everyone construction works completed, after which the largest hydroelectric power station in the world was officially put into operation.
The dam reaches a height of 185 meters and has the ability to pass 116 thousand cubic meters of water every second. The total number of hydraulic units is thirty-four. Moreover, the capacity of each of the thirty-two is 700 megawatts, and the remaining two (they are used for the facility’s own needs) - 50 megawatts. The total power of the Three Gorges is 22.5 gigawatts. As for the generation of electrical energy, the largest hydroelectric power station has the ability to produce about one hundred billion kilowatt-hours annually. It is interesting that the designers initially planned that the station would provide one tenth of all the energy generated in China. But while the construction of the facility was ongoing, the country’s needs increased significantly; now the energy provided by the giant hydroelectric power station is only two percent of the total.
It is impossible not to note the enormous importance that hydroelectric power stations have during floods. Historically, these natural disasters have become a very serious problem for us, because every year they take away a large number of human lives. In this regard, a whole cascade complex of reservoirs is currently being built. In addition to the Three Gorges, it includes the Gezhouba hydroelectric power station, built in 1988. In addition, there are seven more stations that are currently under construction. The largest hydroelectric power station in the world has a reservoir with a capacity of 20 cubic kilometers. Without a doubt, it will significantly reduce the consequences of the annual spring flood. It should be noted that in the absence of a reservoir, any hydroelectric power station becomes dependent on the water level in the river. After all, when it is lowered, the power decreases sharply. And when floods occur most of melt water is discharged in vain.
The Three Gorges Hydroelectric Power Station is located in a picturesque area between the cities of Yichang and Chongqing. The area is home to many cultural and natural attractions. Thanks to its architectural originality, the largest hydroelectric power station in the world has received the definition of “the pearl of the Yangtze River.” In addition, people have always been of great interest in the possibilities scientific and technological progress, so it is not surprising that the Three Gorges hydroelectric station began to be very popular among tourists even during construction.
As for domestic giants, the largest hydroelectric power station in Russia is Sayano-Shushenskaya. Despite the fact that its declared capacity is 6,400 megawatts, it ranks only seventh in the world ranking. In addition to the Three Gorges, the top three included hydroelectric power plants such as the Brazilian-Paraguayan Itaipu (14 thousand megawatts) and the giant Venezuelan hydroelectric power station Guri (10.2 thousand megawatts).