Inner Mongolia wastewater treatment inverter constant pressure water supply system scheme design ~ The design of the water supply control system mainly includes two aspects: one is the design of the mechanical structure; the other is the design of the microcomputer controller and the electrical control of the inverter. The mechanical structure is the basis of the control system and the prerequisite for realizing the control function; the control system of the microcomputer controller to the inverter is the core part of the control function. The design of the mechanical part is relatively simple, and its structure and equipment composition are relatively fixed. 1.1.1 Main components
The composition of the inverter constant pressure water supply system is relatively simple. It is mainly composed of pipes, pumps, controllers, inverters, pressure sensors and other auxiliary equipment. The main components are shown in Figure 1-1.
Figure 1-1 Schematic diagram of the main components of the water supply system
1) Pressure sensor: As the control input of the system, whether the signal can be accurately collected determines the accuracy and reliability of the control system.
2) Controller: It is the core of the entire control system. It detects the external input state and outputs the control amount. After the external input data is processed, the corresponding control amount is output. Such as single-chip computers, programmable logic controllers, computers and so on.
3) Frequency converter: As the follow-up control unit of the core controller, it controls the terminal equipment, and the sewage treatment in Inner Mongolia finally meets the control requirements. This system mainly adopts the AC60 inverter with variable torque load for fans and pumps in a new generation of standard inverters. Power range from 0.75kW to 250kW. With high reliability and flexibility.
4) Water pump: The actuator of the water supply system, which controls the speed of the motor through a frequency converter. Inner Mongolia wastewater treatment finally meets the requirements for controlling the flow of the water pump.
1.1.2 Electrical control system
The electrical control system mainly includes units such as operation panels and electrical control cabinets. In this system, it is necessary to detect the digital input, and also to detect the analog input, and then perform data processing according to the set program and output the control signal.
1.2 Working principle of constant pressure water supply system
The frequency conversion constant pressure water supply system takes the water pressure of the water supply outlet pipe network as the control target, and controls the actual water supply pressure of the outlet main pipe network to follow the set water supply pressure. The set water supply pressure can be a constant or a time-segmented function, which is a constant in each period. Therefore, in a certain period of time, the goal of constant pressure control is to maintain the actual water supply pressure of the outlet manifold network at the set water supply pressure.
Working process of constant pressure water supply system
In the automatic mode, closed-loop control is performed. The system performs start-stop and speed control on the device according to the state of the external sensor. The working process is as follows:
Closed-loop working mode: This mode is the running mode when the system is working normally. When the switch is closed, the Inner Mongolia wastewater treatment system starts a single pump operation. Based on the current water consumption, the inverter automatically adjusts the frequency change based on the feedback value of the sensor. When the current water consumption is not reached when the upper limit is reached, the frequency converter maintains the upper limit operation; if the water consumption decreases during this period, the Inner Mongolia wastewater treatment frequency converter maintains the upper limit operation when the frequency reaches the set lower limit frequency.