Constant Pressure Water Supply System Design And Implementation Based On Variable Frequency

Water is the basic guarantee of the human living. But, the concept of waterresources protection is so weak that water and electric energy waste is very serious,especially in water supply scheduling stage.With the development of science andtechnology, safety and reliability of water supply system is getting more and moreattention.It has been difficult to meet people’s needs by using the traditional fixedfrequency supply mode. Therefore, the water supply plants need to change thetraditional mode, design a set to be able to automatically adjust the water supplyaccording to the water requirements; keep the automatic water supply system beingconstant. In that way,it can make the manual control system response to the watersupply network pressure in time, and solve the problems of serious resources waste andpotential safety hazard.It can improve the automation level of water supply system,reduce equipment maintenance and personnel input, reduce the water supply cost.Firstly, this paper clarifies the energy saving principle of frequency conversionconstant pressure water supply according to the method of adjusting the pumpperformance curve and the basic pump operation. And then, descirbes the control modeand the working process of the whole water supply system, and the design of the overallscheme of the system. Finally, it introduces the design of the software and hardware indetailed.Variable frequency constant pressure water supply system designed in this paper ismainly composed of a water pump, frequency converter, programmable logic controller(PLC), composed of a pressure sensor, a liquid level sensor, man-machine interfaceand low voltage electric appliance. The main design tasks are using PLC to operate aninverter to drive multiple motor, and switch frequency operation and the powerfrequency operation by the operation mode of recycling to achieve pipeline pressure andconstant pump motor. This method is convenient and flexible, has good expansionfunction and communication function, and it has strong versatility which can be appliedto various environmental conditions of the water supply situation.