解决变频恒压供水压力波动的技术应用

Application of Control Technology for Pressure Fluctuation in Frequency-conversion and Constant-pressure Water Supply System

在洗煤厂供水系统中,由于用水负荷无规律的变化,采用传统的水泵全频满负荷运行并通过水泵出口阀门调节用水量的供水方式造成系统压力不稳定,不能满足用户需求或管网设备损坏,因此在供水系统中采用变频器+PID调节器的恒压控制方式,来实现恒压供水。变频恒压供水设备能够实现连续稳压供水;控制系统配套的测量仪表改用了精准度更高的压力传感器,解决了使用远传压力表信号失真的问题。而实际运行中,仍存在系统压力波动,造成系统超压或欠压的现象,需要对配套设施进行改进和反复调试PID参数,确定理想的参数值,实现反应快、超调小的技术要求,保证供水系统的节能、实时、稳定。

In the water supply system for coal preparation plants,due to the irregular water load,when at full capacity,the traditional water pump,adjusting the water volume by outlet valves of the pump,would cause pressure unstable,fail to meet users＇ needs and even damage the pipe network equipment.Therefore,a new system combining a frequency converter and a PID regulator is used to realize constant pressure water supply.The frequency-conversion and constant-pressure water supply system can achieve continuous water supply;more accurate pressure sensors are used in measurement to solve the signal distortion caused by remote pressure instrument.In actual operation,pressure fluctuations cause the over-pressure or under-pressure of the system,so it is necessary to improve the supporting facilities,debug PID parameters,determine ideal parameters,and achieve fast response and small overshoot in order to ensure the energy-saving,real-time and stable water supply system.