Example of inverted siphon project

The Middle Route Project of South-to-North Water Transfer Project is a good economic project. According to the price at the end of 2000, the total investment of the mid-line project is about 92 billion yuan. 40% of these investments will be converted into consumption funds, which will play an important role in expanding domestic demand and stimulating economic growth. According to the multiplier effect of investment, the construction of mid-line project will promote the development of building materials industry, manufacturing industry, transportation industry and tertiary industry. The Middle Route Project will also promote the strategic adjustment of the economic structure in the South-to-North Water Transfer Project, the areas along the water transfer project and the northern water receiving area, and build a water-saving industry, agriculture and society.

According to the general requirements of the socialist market economy, combined with the public characteristics of water resources allocation, the construction and management system of the mid-line project is constructed to ensure the smooth construction and benign operation of the project after completion. According to the principle of "government macro-control, market mechanism operation and water users' participation in management", the Middle Route Project will set up "Middle Route Project Water Source Company" and "Water Supply Limited Liability Company". The water source company is responsible for the dam heightening and later operation management of Danjiangkou Reservoir and sells water to the water supply company. The water supply company is responsible for the construction of the main canal project and its future operation management, and sells the water to the water users association below the outlet.

Water price is the key to the operation of the mid-line project. The calculated water price of the mid-line project is 0.27 ~ 1.27 yuan, which is within the acceptable range of water users and stimulates the enthusiasm of water saving. During the construction period, the South-to-North Water Transfer Project Fund will be established by raising the water price, which will be beneficial to the rational distribution of water rights and create conditions for the collection and management of water charges after the water is connected.

The Middle Route Project of South-to-North Water Transfer Project is an active social project. The dam heightening of Danjiangkou Reservoir requires 300,000 migrants, which is the biggest difficulty in the project construction, but it is also a great opportunity to solve the serious shortage of environmental capacity and the poverty of residents in the reservoir area. According to the estimation of relevant parties, even if the mid-line project is not built, about 654.38+10,000 people around the reservoir area need to be moved out to fundamentally solve the problem of poverty alleviation in the reservoir area. The construction of the Middle Route of South-to-North Water Transfer Project and the relocation of 300,000 migrants to places with better living conditions will greatly improve the ecological environment around the reservoir and improve the living standards of migrants.

After the completion of the mid-line project, the high-quality drinking water of urban residents along the line can be guaranteed, and some cities will no longer be "short of water" in dry years. For millions of local farmers who drink high-fluorine water, brackish water and other deep groundwater containing harmful substances for a long time, the mid-line project will fundamentally improve their drinking water quality.

In a word, the Middle Route Project of South-to-North Water Diversion is a great project of "win-win between North and South", and its important role will be presented continuously with the progress of history. "How can the canal be so clear? Only flowing water comes from the source ",the implementation of the Middle Route Project of South-to-North Water Diversion is the wise decision of the CPC Central Committee and the State Council, the grand long-cherished wish of generations of water conservancy workers, and the ardent expectation of the broad masses of the people. We are determined and confident that under the correct leadership of the CPC Central Committee and the State Council, with the strong support of the Ministry of Water Resources, and with the close cooperation of the people along the route, we will do all the work well to ensure that this grand project will benefit the present and future generations of Zebei at an early date.

Inverted siphon project is actually a water diversion project. It's just a connecting pipe. The principle of atmospheric pressure is Bernoulli equation. Simply put, water flows downwards, but the popular space of water here is pipes, while the popular space of natural water is rivers.

Inverted siphon in BC water supply pipeline in China and ancient Rome.

1975 to 198 1, in the excavation of Yangcheng site in Gaocheng Town, Dengfeng County, Henan Province, it was found that there was an urban pipeline water supply system in the late Warring States period, in which inverted siphon was actually applied. The whole water supply facility consists of water pipes, a control pit for controlling flow, a clarifier for settling sediment, a water storage pit and a water storage tank. There are eight water supply pipelines, arranged from high to low along the terrain, with a total length of several kilometers. The inner diameter of the water pipe is about 12.3 cm, and the water flow can reach 20 ~ 30 liters/second under submerged conditions. The water pipe consists of straight pipe, three-way exhaust pipe, three-way water distribution pipe and four-way water control pipe, all of which are made of ceramic materials. The connection between the ceramic straight pipe and the exhaust pipe of the ceramic tee is shown in Figure 2- 14, and the shape of the ceramic tee is shown in Figure 2- 15. Most water pipes are laid in trenches dug by red sandstone. Groove depth1.2 ~ 2.0m.. ②

Around BC 180, there was a large urban aqueduct in Pagama, an ancient Greek city in Turkey. The water was transported from the source at an altitude of about 360 meters across two valleys to the castle, and the commanding height of the castle was only about 40 meters lower than the source. Among them, when there is an inverted siphon crossing the valley of 100 meters. (3) Vitruvius, a famous architect in ancient Rome, wrote an immortal masterpiece "Ten Books of Architecture" 2000 years ago, describing in detail the construction points of water pipe network at that time. For inverted siphon, Vitruwe also pointed out that in order to operate inverted siphon safely, it is necessary to build piers and exhaust risers. ①

(1) Do you want a tube? The calculation of river gradient in single dike and the description of hydraulic jump were first put forward by Mr. Yao Hanyuan in 1962.

② Henan Institute of Cultural Relics, Archaeological Department of Chinese History Museum, Wang Chenggang and Yangcheng in Dengfeng, Cultural Relics Publishing House, 1992, pp. 229-246.

(3) see チヤルズ? シンガ, first edition, translated by Hirata Hiroshi and Yagi Mulong, History of Technology-Medieval Mediterranean Civilization (Volume II), Zhu Mo Studies, pp. 58 1 ~ 583. Peter james's Ancient Inventions, translated by Yan Kewei, World Ancient Inventions, World Knowledge Publishing House, 1999, p. 388.

There is a form of water pipe called inverted siphon, which is an intercommunication hydraulic structure often used when the channel crosses roads, rivers or valleys. As early as more than 2000 years ago, China has been successfully applied. Like siphon, the facade is arched; The difference is that its bow bends downward. Moreover, although the principle of inverted siphon and siphon is the same, both rely on the water level difference between upstream and downstream, inverted siphon is more popular because it does not need to create a vacuum in the pipeline when it starts working.