| Water supply facilities as an important part of urban infrastructure, is the lifeline to ensure the sustainable development of the city. In recent years, with the vigorous implementation of the great strategy of the rise of the central China, Henan's economy has made rapid development. But the biggest problem behind economic development is the pollution of water resources, especially drinking water. In order to improve the water quality and to improve the water supply efficiency, it is necessary to carry out the automatic control of the urban water supply system. As a major province of water shortage, this initiative will undoubtedly be of great significance to save water resources and reduce pollution. The topic of this paper comes from the water supply and energy saving project of Hebi city water group in Henan Province, The group of the existing water supply system automation is improved, in order to achieve the purpose of highly intelligent, also hope the study can provide reference and basis for water supply in the north area of Henan Province. Therefore, the paper has done a lot of work, mainly in the following three aspects.1. The water supply control system of the fourth water plant in Hebi city is analyzed in this paper. In order to achieve automatic control effect, the chlorine dosing control system, control system, filter control system and variable frequency control system were designed in detail. The design requirement is to make water in the process of chlorine and turbidity reached the industry standard, and to achieve stable water supply in the case of constant pressure.2. This thesis mainly uses the PLC technology to realize the automatic control of the water plant. The waterworks automatic control system uses S7-300 model PLC as master station, distributing I/O from the station. In this paper, the automatic control of the filter is discussed in detail. Finally, the V filter is adopted to realize constant water level filtration, filter grid automatic back flushing and other important control. In this paper, the frequency conversion constant pressure control flow of the two stage pumping station pump unit is analyzed, and the flow chart of the variable frequency constant pressure water supply control system is established. In order to make the factory water pressure constant, the paper adopts the principle of speed regulation and energy saving control. The control system of chlorination do detailed control process preparation, and use step 7 software of corresponding control flow chart for programming. After that we put the program into the PLC, and the procedure was carried out on the spot.3. In order to solve the problem of water plant communication, this paper uses the field bus technology. This thesis discusses and expounds the field bus communication network, introduces the concept of fieldbus, network structure, communication model and so on. According to the practical application of water plant, this thesis puts forward a communication scheme based on PROFIBUS field bus. According to the actual communication requirements of each process, the paper designs the network configuration of the fieldbus network. According to the network configuration diagram, complete hardware configuration, and finally through the configuration of the address to complete the preparation of the program.The automic control system,designed in this thesis,has been applied to the link of water making. In the whole automic control process, the system can operate stably, and the error is low to zero. It not only meets the requirement of design and achieve the desired effect, but the more importance is to make water-producing process and saved labors. Of course, this process also greatly improves the quality of drinking water of residents, and creates enormously economic, which will benefits the running-water comply. |
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