Energy-saving Analysis And Operation Optimization Of Laminated Pressure Water Supply Equipment

As the"last one kilometer"of urban water supply system,secondary water supply is an important livelihood project and the basic guarantee of improving people’s welfare.The energy consumption of secondary water supply pump houses accounts for a large proportion of the whole city water supply energy consumption,most pump houses with high energy consumption problems need to be solved.In order to improve the efficiency of the secondary water supply equipment and give full play to the advantages of energy saving,this paper mainly focuses on the operation optimization and energy saving analysis of the superimposed water supply equipments.Firstly,the energy consumption composition and the relationship between efficiency and speed regulation ratio in each energy transfer link are studied,and the range of speed regulation is 75%～100%.According to each link efficiency rough calculation,the theoretical comprehensive efficiency of the equipment should be more than 50%,compared with the research group’s actual comprehensive efficiency found that the equipment in operation efficiency is generally low,further clear the importance of equipment energy-saving optimization.The method of conic is used to fit the characteristic curve of water pump,and the solution of energy consumption of superimposed pressure water supply equipment is derived.Secondly,the paper studies the operation optimization of laminated water supply equipment.Taking the shape of pump characteristic curve as the cut-in point,combined with the pressure fluctuation of municipal pipe network,it is found that the pump with steep Q-H characteristic curve should be chosen when the municipal pressure fluctuates greatly.The method to reduce or eliminate the"transition low efficiency zone"is to select pumps with wide range of high efficiency zone and select full frequency control.The starting and stopping point of auxiliary pump and the type selection of air pressure tank for medium and small flow rate are clarified.The relationship between the regulating volume of air tank and the value of precharging pressure P₀andα_bis derived.The results show that whenα_bis the lower limit of the interval and P₀=P₁,the regulating volume of the pressure tank reaches the maximum.The Bernoulli equation is established between the access point of municipal pipe network and the intake of steady flow tank.The method to determine the setting height of stable flow tank is derived.A mathematical model of the influence of superimposed pressure water supply equipment on the pressure of municipal pipe network is established.According to the model,it is concluded that the equipment is placed near the water plant and has a large diameter of pipe network.At the same time,reducing the proportion of equipment intake in the transfer flow of municipal pipe network can effectively reduce the impact of equipment on municipal pipe networks.Finally,taking the secondary water supply system of a residential area in North A city as an example,the design parameters of high area are calculated reasonably.The main pump and small flow water supply equipment are optimized,combined with the selection of auxiliary pump to determine the pre-filling pressure and maximum regulating volume of the pneumatic tank.According to the measured water consumption law and the fluctuation of municipal pressure,the pump group is reasonably arranged and the total energy consumption before and after optimization is calculated.The results show that the optimized energy saving is 17.88k W·h,the energy saving rate is 16.89%.When the two main pumps are running efficiently,the optimized program can save 13.8%.