Energy Conservation Control Technology For Building Water Supply Based On Pressure-superposed Of Pump Station

At present,due to the global energy and environmental issues,energy conservation and emission reduction requirements have been in various fields.It is counted that 30%~40% of the total electricity consumption is water pumps and fans consumption,in which large proportion is used for secondary pressure of building water supply,and there is also great potential of energy conservation.In recent years,due to the small occupied space and eliminating secondary pollution,water supply system with Variable Frequency Drive(VFD)has been widely used.In fact,the energy saving effect is not significant.Pressure-superposed water supply(PSWS)based on pumps directly connect with the municipal-pipe network has been applied in Japan,US since the end of 1990 s.So PSWS can effectively use the incoming water pressure of the municipal-pipe network.There is no doubt that the PSWS technology is more energy saving.It is the future trend of the development of building water supply,and it is with great significance to energy-saving and emission reduction.In view of the effective means to implement the energy saving,this paper combines the pressure-superposed water supply with variable pressure and flow water supply.Considering the problems existing in the combination of pressuresuperposed water supply and the traditional second-side water supply,the solution and method for the control of pressure-superposed water supply are given by the characteristic of the water pump and Variable Frequency Drive(VFD)energy-saving,which can reduce the pump lift and avoid the large "static lift".Basic analysis,calculation and simulation verification for resistance to the user-side of the tube are developed to determinate the water supply pressure.It can provide the basis for the variable frequency control water supply system.According to the proposed control method and the determined control pressure,variable frequency control system of water supply pumps is designed,and then PLC,inverter,touch screen,GPRS communication technology are used to develop group pumps control system.In particular,PLC is used to achieve control logic,frequency converter is used to achieve variable frequency speed,touch screen is used to achieve on-site human-computer interaction,and GPRS is used to achieve remote wireless communication.The software and hardware of group control system are designed,assembled and debugged.Then the test platform is built to test the constant frequency and variable frequency water supply,to test energy saving effect and verify the proposed water supply control method and control device,which can provide reference for the engineering application.