The largest water plant in Asia-Beijing No.9 Water Plant.
Beijing No.9 Water Plant was built by Beijing Water Supply Company, designed by Beijing Municipal Engineering Design and Research Institute, and constructed by Beijing No.3 Municipal Engineering Company. Construction began in 1980s, with a scale of 6,543.8+500,000 m3/d. It is a modern large-scale surface water plant with advanced water treatment technology, complete equipment, high automation control level and excellent effluent quality. It will be built in three phases, each with a scale of 500,000 m3/day ... The first phase 1990, the second phase 1995 and the third phase 1999 will be put into production with a capacity of 250,000 m3/d, all of which were completed in 2000.
The first phase of the project takes water from Huairou Reservoir, and the reservoir water passes through a water conveyance tunnel with a length of 100 m and a diameter of 2.4 m to Huairou Water Plant near the west dam of Huairou Reservoir. After pre-chlorination and pressurization, it is transported to the net distribution water plant by a steel water pipeline with a length of 42 kilometers and a diameter of 2.2 meters. The second and third phases of the project take water from the Chaohe reservoir area of Miyun Reservoir. The water from the reservoir reaches Miyun water intake station through a water tunnel with a length of 3 kilometers and a diameter of 3.5 meters. The water intake station is equipped with a flow control valve room and chlorination facilities. After pre-chlorination, water is transported by gravity from a ductile iron pipe with a length of 33 kilometers and a diameter of 2.6 meters and two steel water pipes with a length of 4 1.4 kilometers and a diameter of 2.2 meters to the net water distribution plant. After the first phase of the project was put into operation, the water shortage in Beijing was alleviated, especially in Beijing19901. After the second phase of the project is completed, the water supply of No.9 Plant is 850,000 m3/d, meeting the peak water demand in Beijing.
The water quality of Miyun Reservoir and Huairou Reservoir meets the national second-class surface water quality standard. The requirements of purified water quality are generally turbidity not greater than 0.5NTU, 2 NTU in special cases, chroma not greater than 5 degrees and odor threshold not greater than 4. According to the water quality and purified water quality requirements of the two reservoirs, the water treatment items are turbidity, chromaticity, odor and algae. Considering the special situation and requirements of Beijing, the conventional treatment of coagulation and sedimentation and advanced treatment of activated carbon are selected for this project.
In order to save chemicals, a jumper is set up, and direct filtration or conventional treatment can be flexibly adopted according to the change of raw water quality. The first, second and third phases of the project are quite different in construction and selection. The first phase of the project is divided into three series, with rapid mixing, mechanical accelerated clarification, siphon filtration and carbon adsorption treatment structures; The second and third phases of the project are divided into two series, which adopt the structure of rapid mixing, hydraulic flocculation with plug-flow large corrugated plate, sedimentation with large corrugated inclined plate in lateral flow, homogeneous coal filtration and carbon adsorption treatment. The first, second and third phases all adopt automatic vacuum chlorinator, pressure ammoniator and automatic dosing pump. The first, second and third phases of 39 tons of daily dry sludge were stored, concentrated, dehydrated and transported by mud cakes, and were completed and put into operation on 1995. The moisture content of mud cake is about 50% ~ 60%, which fills a blank in the field of sludge treatment in water purification plants in China.
Install process detection instrument and decentralized water production process control system. Set up a central control room in the office building of the water purification plant for supervision and management. On-site process control stations 10, including Huairou water intake plant, Miyun water intake station, phase I and II coagulation and sedimentation, phase I and II filtration and carbon adsorption, phase I and II water distribution and power transformation, phase III coagulation and sedimentation, phase III filtration, carbon adsorption, phase III water distribution, power transformation and sludge treatment.
In the second and third phases of the project, a number of efficient processes such as plug-flow corrugated plate flocculation and lateral flow corrugated inclined plate sedimentation were adopted. On this basis, intensive group arrangement is adopted, which shortens the length of pipelines and cables between various structures, facilitates management, saves 60 mu of land and reduces the project cost.
A number of new equipment, such as multi-nozzle flow control valve, rapid axial-flow mechanical stirrer, current-source frequency converter composed of 2500 kW crystal valve tube (SCR), voltage-source frequency converter composed of 2550 kW insulated gate bipolar transistor (IGBT), 1 10 kVSF6 combined electrical appliance and power station microcomputer protection device, have been adopted in this project. In the second phase, the nodular cast iron pipe with a diameter of 2.6 m was introduced, and the wall thickness was reduced from 25 mm to 23 mm by using advanced technologies such as flow regulation, energy dissipation and pressure relief, which saved the engineering investment. The water distribution pump adopts speed regulating device to save electricity.
In the second and third stages, a homogeneous coal-fired filter is used, which has a large pollution interception capacity and a long filtration period, and the gas-water combined flushing saves water by 40%. The design of the first and second phases of the project won the second prize of excellent design from the Ministry of Construction.
The daily water supply scale is 6.5438+0.5 million tons. Won the china municipal engineering Gold Cup Award and Zhan Tianyou Award.
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