Research And Development Of Unattended Control System For Heat Exchange Station

This paper studies the implementation method of the unattended control system of the heat exchange station.First,this paper analyzes the requirements of the control system,which mainly includes three aspects,the control of the backwater temperature at the side of the secondary network,the control of water supply and pressure relief to ensure the steady pressure of the pipe network,and the frequency conversion speed regulation control of the circulating pump.According to the requirements of the unmanned control system of heat exchange station,the overall structure of the unmanned control system is designed,which includes local intelligent controller,wireless transmission network and monitoring platform.Based on the requirements and overall design of the heat exchange station,the remote control system,local measurement and control system of the heat exchange station unattended were developed.The remote control system is consists of the monitoring and control terminal signal transmission system,front and rear end transmission network and monitoring center.The monitoring and control terminal signal transmission system is consists of two parts of hardware by the 4G wireless router and the GPRS DTU module.Front and rear end transmission network is connected to the Internet through VPN/PPTP protocol to complete the measurement and control signal and data output and input of heat exchange station;The back-end transmission network uses VPN dial-up to connect with the Internet to receive monitoring signals and send monitoring instructions.Monitoring center realizes the storage of real-time measurement and control data of heat exchange station,real-time status monitoring of site operation,query and analysis of historical data,fault and alarm display,and control signal feedback.The local measurement and control system of the heat exchange station is composed of signal acquisition system,PLC controller and MCGS.The signal acquisition system is composed of temperature sensors,pressure sensors and flow sensors,which collect the operation data of the primary and secondary networks and transmit them to the PLC controller.Based on the fuzzy PID algorithm PLC control the frequency converter and the valve,complete the adjustment of water circulation flow,water supply and pressure relief,and finally achieve the control of the temperature.MCGS configuration software provides a human-computer interface.This paper takes the transformation of heat exchange station in Anyangli community of Tianjin as a specific case.Through the analysis of the overall demand of the system and the design of the remote control system and the local measurement and control system,the temperature of the heat exchange station is well controlled,and the purpose of energy saving,emission reduction and manpower reduction is achieved.