Analysis And Research On Non-negative Pressure Water Supply System

This article introduces the traditional secondary water supply. It makes close analysis onthe advantages, disadvantages and application conditions of all kinds of water supply mode,and it was pointed out that the existing problems of traditional secondary water supply, such aswater and energy waste, secondary pollution of water and so on. It is the combination of theurban municipal water supply pipe network and user end as a whole. It takes full advantage ofthe municipal water supply pipe network excess pressure, and operates by frequency constantpressure water supply mode. It achieves the goal that is saving water and energy, preventingsecondary pollution of water. And then, the composition of the non-negative pressure watersupply system, working principles, scope of application, technology advantages, as well asfrequency conversion water supply technology and non-negative pressure technology isanalyzed and researched to prepare for system modeling.In this article, based on the practical engineering, this software was selected as a platform,to build the non-negative pressure water system model, and then simulate the workingconditions of the different amount of water, when it was used to simulate, when the municipalwater supply pipe network pressure, pump configuration and water consumption was different.Through analyzing the results, the author finally comes to the conclusion that is designed toprovide the reference, provide the basis for the actual system operation and management.The simulation results show that:(1) There is obvious energy saving effect when using Non-negative pressure watersupply mode relative to the normal frequency of water supply mode, in this example, therelative energy-saving rate is28%.(2) Only a reasonable choice pressurization equipment, there could be a better energysaving effect. Through the comparative study of the two schemes, a day of two small pumpwater supply mode consumed39kWh less than a big pump.(3) Through analyzing operation of the system in a day, it is found that steady pressurecompensation and pumps operated normally, when the minimum municipal-pipeline-networkpressure is0.30MPa, and the device can meet the demand of water supply project.(4) The system is operated normally when municipal pressure ranged in0.30~0.38MPa,the pressure drop of service pipe is small, and the municipal network is not influenced. Withthe municipal available excess pressure increasing, energy saving rate will increase. When themunicipal network water supply pressure is insufficient, in order to prevent the creation ofnegative pressure, the pump speed can’t increase indefinitely, and water supply quantity willbe reduced.