Distributed redundant constant-pressure water supply control system

Abstract

The invention discloses a distributed redundant control system. According to the system, pump revolution speed is dynamically adjusted based on the pressure, flow, temperature and other variables of fluid so as to achieve an expected control objective. The product is composed of one central management and coordination unit and n distributed control units which are independent and redundant from one another and can run autonomously, wherein each unit is in whole-network information transmission and modular design; the central management and coordination unit is only responsible for managing andcoordinating the control units, and the right of control is handed over to each control unit; and the central management and coordination unit can perform cascading in the same network segment or across network segments. In a pressure-maintaining standby state based on a multi-variable weight algorithm, the system does not do idle work due to dynamic flow compensation. The system has the advantages of high reliability, high continuity, distributed running, strong extensibility and energy preservation, therefore, the defects that through a traditional central control mode, reliability is poor,and equipment overhaul requires shutdown and water supply cut-off are overcome, and the problems that water supply continuity is not high, and the scale is not large in the industry are solved. In this way, the after-sales service pattern in the current industry is changed, and after-sales cost is greatly lowered.

Description

technical field [0001] The invention relates to a constant-pressure water supply control system, in particular to a high-reliability, on-line maintenance and energy-saving constant-pressure water supply control system. Background technique [0002] Basic Concepts in Constant Pressure Water Supply Control System [0003] Sensor (sensor): Pipeline pressure detection instrumentation, divided into digital / analog type, is the signal acquisition component of the control system. [0004] PLC (Programmable Logic Controller): The control core of the control system. Its functions are signal collection, calculation processing, and output of calculation processing results to the actuators. [0005] Driver (variable frequency drive): It is the terminal actuator of the control system, which uses electric energy to drive the pump unit to run. [0006] HMI (Human-Machine Interface): A touch screen for human-computer interaction, which visualizes the control process. [0007] The constant...

AI Technical Summary

Problems solved by technology

If the central control unit breaks down, the entire system will be paralyzed, that is, "one damage and all damage"

In addition to this, another disadvantage of centralized control is that it cannot be maintained "online", that is, maintenance must be performed after the equipment is shut down, which affects the continuity of equipment water supply

[0027] 2. High after-sales cost

[0028] 3. The expansion ability is not strong, and it cannot be used for large-scale water supply systems

[0029] 4. During the peak period of water consumption, the pressure at the end of the pipe network is insufficient

[0030] Inaccurate judgment of the pressure-holding standby condition of the control system

At present, the general practice in the industry is to use the pump operating frequency lower than the set pressure-holding threshold frequency as the judgment condition. Since the PID operation control is close to the set value and the feedback value, the PID output value is basically unchanged, that is, the pump operating frequency The size is also unchanged, so the problem of inaccurate judgment of the pressure-holding standby condition occurs

Either the pressure cannot be maintained normally, or the pressure is maintained frequently. The former causes the temperature of the pump chamber to be too high, and the latter frequently starts and stops the pump, both of which shorten the service life of the pump and waste energy.

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