Study On The Water-energy Nexus In Water Treatment And Transportation Of A High Quality Water Plant In City

Water resource and energy is one of the main factors that affect the development of society, and there is a close nexus between them. There is a great meaning of the research on the relationship between water and energy, which can develop and use water and energy resource rationally and improve the efficiency of the urban water system. In this paper, basing on the data of city’s high quality water plant from the 2012-2014 annual production and service area water meter, using the cluster analysis and linear regression theory, the water-energy nexus of the whole high quality water plant and the process of water treatment and water transportion were studied on, and the corresponding models of water-energy nexus were established. The energy intensity (EI) is introduced to characterize the nexus between water and energy consumption, using to improve the work efficiency of the water plant.The variation law of total EI at different time and temperature was also explored. By using the method of combination of seasonal index and grey model, the energy consumption of the water treatment process, water transport process, the office building and the water supply of the water plant in the high quality water plant were predicted, in order to making an in-depth study of the change of the work efficiency of the water plant. The specific research results are as follows:(1) In the year of 2012-2014, the high quality water plant’s water treatment process, water transport process and the office building’s energy consumption were cyclical changes. Among them, the energy consumption of office building is the main factor, affectting the total energy consumption of the water plant, accounting for the total energy consumption of the 40-50%. The series of water supply data of the water plant also showed seasonal cyclical fluctuations. The water intake, water production and water supply data series have the same trend that increasing with the extension of time. And the three parties data have seasonal periodicity.(2) The total EI of high quality water plant is seasonal variation. Its peak usually occurs in June of each year, which shows that the quantity of energy consumption is large in this time. When the weather temperature is 13 C-28 C, the total EI of the high quality water plant is basically stable in the range of 439Kwh/Km3+25Kwh/Km3; When the temperature is greater than 29℃, the El will be significantly increased, the average level of up to 583 Kwh/Km3.(3) There is a liner relationship between the quantity of water supply(Qg) and the energy consumption(Eg) in the water transport process, and a quadratic relationship between the production water(Qz) and the energy consumption(Ez) in the water treatment process, and a linear relationship between water intake(Qj) and total electricity consumption(EJ). The specific models are as follows:1) Eg=130.20Qg+24.879 (The process of water transport)2) Ez=1.33Qz--45.42Qz+8249.48 (The process of water treatment)3) E=0.7466Qj (The whole water plant)(4) The seasonal-grey forecasting model of water supply, water transport process, water treatment process and the office building’s energy consumption were established. The average absolute error corresponding to 6.12%,6.18%,4.82% and 4.46% respectively and the relative error variance were 0.03,0.05,0.04,0.03. Each model with high accuracy and good stability.(5) With Java and SQLserver database software as the operating environment, based on the concept of Dao/Domain/Service layered design, the visualization tools was been built. The tool has the function which can query the hourly, daliy, monthly data. The tool also can calculate and analysis the recording data. It can improve the work efficiency of water plant.