Automatic Control System for Sewage Treatment Project of Daxinan Lingang Industrial Park in Fangchenggang City

Automatic Control System for Sewage Treatment Project of Daxinan Lingang Industrial Park in Fangchenggang City

1. Project Introduction

This project is located in Zone B of Southwest Lingang Industrial Park, Port District, Fangchenggang City, Guangxi Province. The first phase of the project treats 40000 cubic meters of sewage per day. The supporting automatic control systems include: central control room of the comprehensive building, PLC control cabinet of 1 # external lifting pump station (PLC1), PLC control cabinet of 2 # external lifting pump station (PLC2), PLC control cabinet of sewage pump room (PLC3), PLC control cabinet of dosing room (PLC4), PLC control cabinet of blower room (PLC5), PLC control cabinet of online monitoring instrument room (PLC6), PLC control cabinet of transformer and distribution room (PLC7), PLC control cabinet of internal lifting pump room (PLC8), fine grid and sand settling room. The PLC control cabinet for the pool (PLC9) and the PLC control cabinet for the biological pool (PLC10) use the ST40 and ST60 of S7-200SMART, respectively. Eight PLCs are connected to a ring network through Ethernet to fiber optic transmission bridges, enabling data exchange between them. The data from two external PLCs is transmitted back to the central control room through the GPRS network, Thus achieving the goal of centralized monitoring of central control. Two of the external PLCs are also equipped with 10 inch touch screens, which facilitates current operations and data queries; The central control room of the comprehensive building is equipped with a 4-station control console and two upper computers with dual hot standby. There are two UPS units, one placed in the central control room of the comprehensive building and the other placed next to the PLC cabinet in the power distribution room.

In addition, the two S7-200 PLC control cabinets supporting the large equipment dewatering machine and blower are exchanged by the blower room PLC5 through the 485 based Modbus RTU standard protocol, and finally transmitted to the central control room through optical fiber to achieve upper computer monitoring.

More than 40 intelligent power instruments in the power transformation and distribution room are collected by the PLC control cabinet (PLC7) of the power transformation and distribution room through 2 channels of 485 based Modbus RTU standard protocol, and then transmitted to the central control room through optical fibers, achieving centralized monitoring of power parameters and ultimately achieving automatic control of the entire plant.