Design And Implementation Of Ventilation Monitoring System In Underground Engineering Based On PLC

As an important supporting system of the underground engineering.the ventilation system can provide necessary clean air for the survival of the internal personnel of the project.In a relatively closed underground engineering.once the ventilation system fails.it will inevitably affect the safety of personnel inside the project.A large number of underguround ergineering have been completed in our country.Due to the restriction of funds and other conditions,the ventilation systems of many underground engineering are basically not equipped with monitoring systems.The equipment operation control and equipment operation status records are mainly manual.This backward monitoring and management mode can neither monitor the runining status of the ventilation system in real time,nor guarantee the continuity of recorded data,nor can it give early warning and fault judgment for abnormal conditions.On the basis of fully investigating the current situation and requirements of ventilation monitoring svstems,this paper has carried out related design and development work such as ventilation monitoring system architecture,system hardware and software.Based on PLC and MCGS softxware.a distributed ventilation monitoring system is developed,which realizes remote and on-site controlL manual and automatic control of the system,as well as real-time monitoring of system operation status and fault early warning.The monitoring system consists of a three-layer distributecd architecture.which includes management layer.middle layer and field layer.The field layer of the monitoring system mainly includes fans.closed valves.various sensors,etc.The ventilation system adopts the structure of separate fans.which can switch the three ventilation modes of cleaning,poison filtering and isolation according to the external air pollution.By arranging various sensors.real-time data such as system wind speed,fan shaft temperature.fan xvibration and fan current are collected.The middle layer of the monitoring system is designed with PLC and touch screen.which realizes the functions of field device control,data transmission.The management layer of the monitoring system is a man-machine interaction system designed based on MCGS,which realizes the functions of remote monitoring and data management in real time through a series of visual system.On this basis,the mornitoring system adopts digital PID control and frequency conversion technology,and adopts relay feedback self-tuning method to complete PID parameter tuning of the control system,which realizes stable control of ventilation output according to demand and enables the system to operate with energy saving and high efficiency.