Discussion on the electrical transformation of pip

2022-09-30
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Introduction: Nanjing Water Supply Corporation Nanjing is the capital of Jiangsu Province and the ancient capital of Six Dynasties with a long history. Nanjing has been supplying water for more than 70 years. Since the reform and opening up, with the development of economy, the construction of urban water supply has been strengthened. At present, the water supply capacity of Nanjing has reached 2million meters, so the attachment is mainly used to fix the sample for 3/day, and the length of the pipeline is more than 2400 kilometers. In recent years, our company has mainly carried out pipe reconstruction to solve the problem of insufficient water transmission and distribution capacity in the past. Now, the main water transmission and distribution pipes with a diameter of more than DN500 in the urban area are formed in a ring, and the layout is reasonable

key words: Nanjing pipe renovation

relevant station middle station: pipe design, maintenance and optimization

Nanjing Municipal Water Supply Corporation Nanjing is the capital of Jiangsu Province and the ancient capital of Six Dynasties with a long history. Nanjing has been supplying water for more than 70 years. Since the reform and opening up, with the development of economy, the construction of urban water supply has been strengthened. At present, the water supply capacity of Nanjing has reached 2million m3/day, and the pipeline length is more than 2400 kilometers. In recent years, our company has mainly carried out pipe reconstruction to solve the problem of insufficient water transmission and distribution capacity in the past. Now, the main water transmission and distribution pipes with a diameter of more than DN500 in the urban area are formed in a ring, and the layout is reasonable

first, the homogenization of existing domestic equipment in water supply pipes is also serious. The main problem is that after a few years of vigorous transformation, the main water transmission pipe in Nanjing has been basically transformed, and the main problem is the problem of water distribution branch pipes. Nanjing has a long history of water supply, and many of the water supply pipes have been laid for a long time. Most of these pipes are made of gray cast iron pipes, which are seriously rusted and scaled, and explosive pipes, affecting the water quality and safety of water supply. Due to the expansion of the scale, the increase of population and the improvement of living standards in some residential areas, the water consumption has increased significantly, resulting in the small diameter of the original water distribution pipeline, which leads to the phenomenon that the pressure of the water transmission main near the community is normal, while the water supply pressure inside the community is insufficient

due to the development of the surrounding areas of the city and the urbanization process of suburban rural areas, the original water supply pipe can no longer meet the demand, and there is an urgent need to expand the water supply capacity to the surrounding areas of the city

II. Principles and methods of pipe transformation

the main purpose of pipe transformation is to make the pipe operation more economical on the premise of meeting the water supply requirements. Therefore, a comprehensive understanding of the operation of the current pipe is conducive to the pipe transformation. Establishing a pipe model and simulating the actual operation of the pipe is a practical method to analyze the pipe and guide the reconstruction and construction of the pipe. At present, our company has established a pipe model with 260 nodes and 460 pipe sections with pipe diameters above DN500. The "real time hydraulic simulation software of water supply pipe" jointly developed by Nanjing Water Supply Corporation and Tongji University is used for hydraulic simulation and verification. The software mainly has five functional modules: 1 Adjustment of multi water source pipe 2 Pipe planning and design and optimization calculation of reconstruction and expansion scheme 3 Real time simulation of hydraulic state of multi water source pipe 4 Management status and operation management database and information query 5 Graphics engine. The model has been checked many times and has high accuracy. Through the hydraulic analysis of the model, find out the pipeline with excessive velocity, poor hydraulic conditions and large head loss in the pipe, and transform it. At the same time, combined with the urban water supply planning and urban construction, the main water transmission and distribution pipes are arranged and checked by the model, so that the urban main water transmission and distribution pipes are economical and reasonable. In the future, our company will establish a more microscopic management model based on the newly built GIS to guide the internal management transformation of the community

for pipelines with too large flow rate and small pipe diameter, the following methods are mainly used for reconstruction

1. Change management. Expand the original pipeline to a suitable pipe diameter

2. If conditions permit, lay another section of new pipeline on the same route. It is relatively necessary to change management so as to save investment. 3. Reduce the load of this pipe section by transforming other pipes or laying pipes near them

pipes with long laying time, serious internal corrosion and scaling, poor hydraulic conditions and poor pipe materials are mainly transformed by changing pipes. The new pipeline adopts pipes with high strength, corrosion resistance and low cost. Ductile iron pipes are mainly used for pipes with diameter above DN300. Secondly, due to its own characteristics, such as no water operation when opening T-port, glass fiber reinforced plastic pipe can only be used as water transmission main pipe in the case of long distance and no water connection by users. UPVC pipes are basically used for pipes with diameter below DN300, and ductile iron pipes are also used for roads with high bearing capacity. The corrosion and scaling are not too serious, but the hydraulic conditions are not good. In the future, we plan to try to use technologies such as pipe scraping and plastic lining

III. some problems to be solved in pipe reconstruction

the code for urban water supply engineering planning puts forward the requirement of 28 meters of service head at the user's connection point for the water supply pressure of urban distribution pipes. In this way, the water below the 6th floor of the ordinary residential building will be directly supplied by the municipal pipe, and the regulation and storage capacity of the original roof water tank will disappear. The existing water supply pipe will be difficult to meet the maximum water supply demand. How to reasonably solve this problem will be an urgent research topic for our company, whether it is through the transformation of pipes, the improvement of the factory pressure of water plants, or the construction of more residential booster stations for secondary booster water supply

at present, the majority of users have a high voice for meter reading to households, and the water department inevitably involves the indoor water supply of buildings. The state has expressly stipulated that cold galvanized steel pipes should not be used in new houses, but there is always one product that is suitable for ordinary athletes. There are many kinds of products, such as UPVC pipes, PE pipes, PPR pipes, ABS pipes, aluminum-plastic composite pipes, steel plastic pipes, etc. What kind of pipes should be used, which can not only ensure the water quality of users, but also facilitate the construction, operation management and maintenance, and the cost is economic, which is still difficult to determine at present

valves are indispensable equipment in water supply pipes. In the pipeline engineering construction and pipeline operation emergencies, we often encounter the situation that the scope of water cut-off and pressure reduction can not be expanded due to valve failure. Therefore, how to select the appropriate valve, reasonably arrange the valve and reduce the valve failure rate is also a problem to be solved

our company has been paying close attention to the new trends in the development of pipe technology at home and abroad, and is now cooperating with Tongji University to develop "optimal scheduling of water supply pipes"

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