Research On Energy Saving Of Non-negative Pressure Secondary Water Supply System For High Buildings

The main energy consumption of water supply and drainage in high buildings is the energy consumption of the secondary water supply system.The non-negative pressure secondary water supply system as a new secondary water supply system,compared to conventional methods,could save more energy and be safer.However,the existing non-negative pressure secondary water supply system is quite conservative in design,not fully exerting the potential of energy saving.In addition,there are some problems with water supply system,for example,the rough strategy of water supply is and high energy costs under low water consumption.This paper proposes a fine secondary water supply strategy design idea based on the characteristics of building water,in order to further reduce the energy consumption of the non-negative pressure secondary water supply system.The research discoveries are as follows:(1)by taking full consideration of the effect of the time-varied secondary water supply flow on the energy consumption of the pumping station,conducting second-order fit of water pump characteristic curve,and building the calculation model of the energy consumption of the pump,the actual monitoring data has validated that the error rate is under 1%.The model is of has high simulation accuracy and reliable results for the pump energy consumption.(2)by monitoring and analyzing the water consumption data of activity centers and students'dormitories,the results show that the water use characteristics of the high area in activity center are clear.The water is almost useless from 23:00 AM to 7:00 PM of next day.In this period,a large amount of energy waves will be caused by the normal opening of the non-negative pressure pump station.As a result,the water supply during this period can be ensured while reducing the energy consumption by using suitable small flow pump.There is a very obvious time distribution feature in the water use of students' dormitories.Large amount of water use is from 7:00 AM to 8:00 AM and from 22:00 PM to 1:00 PM the next day,while the water use during the rest of the day is medium degree.The large flow pumps are suggested to be used to ensure adequate water supply during the peak period of water use,and the energy consumption could be reduced by the use of small flow water pumps during the rest of day.The water consumption of the building is related to the condition of the building,the time of use and the number of people using water.It is important to identify the use of building and the ways of use in order to estimate the quantity and characteristics of water use.(3)the energy saving effect of the non-negative pressure secondary water supply system is affected by water quantity,water head,equipping variable frequency pumps and the scheme variable frequency control.According to the previous research results,which is based on the water characteristics and energy consumption calculation model of activity center and student dormitory,the energy saving design simulation optimization of two buildings is carried out by matching different flow pumps in different characteristics of water supply.The energy saving rate of college students' activity center and students'dormitory is up to 50%and more than 30%respectively,and the energy saving effect is obvious.(4)by monitoring the water quality of non-negative pressure secondary water supply system for a period of two months,the results show that the water quality conforms to the national sanitary standard and it is the safety secondary water supply mode.