Application Of Distributed Monitoring System For City Heat-supply Network Based On WinCC OA

In recent years,the environmental problems,especially the air pollution,which is closely related to our life,has drawn more and more attention.At present,in North China and other heat-supply towns,the mode of centralized heat-supply are applied during winter time.Normally,the centralized heat-supply system consists of a plurality of heat-exchange stations and pumping stations,which are in dispersed locations.In most heat-exchange stations,the manual monitoring method has been applied,and each of the heat-exchange station is independently operated,so it is difficult to achieve the best overall condition of the whole heat-supply system.Besides,it can easily lead to the heat imbalance and impact the heat-supply effect,which causes a great waste of energy.In order to make the mode of centralized heat-supply be better optimized,and make both hydraulic and thermal have better balance regulation abilities,this project designs a distributed monitoring system for city heat-supply network based on WinCC OA.This project is mainly focused on the device architecture,network architecture,PLC development,configuration software development,final running and other aspects of the distributed monitoring system.The main work is as follows:The distributed monitoring system consists of monitoring center and heat-exchange automatic control system.The design of monitoring center adopts redundant server structure,the upper computer software is achieved through WinCC OA,thus completing the design of the monitoring center overall function.The heat-exchange automatic control system adopts PLC as the control core,and combines with the distributed pump,circulated pump,make-up pump,soften water tank and the sensor which tests temperature,pressure and flow to implement technology requirements of heat-exchange station’s local automatic control function.Between monitoring center and heat-exchange station,the network communication architecture is established through the communication equipment.The heat-exchange station establishes static domain through VPN equipment,and the control center establishes communication connection with heat-exchange station PLC equipment through the domain access mode.The server makes the mobile client realize the system data monitoring through the network release function.In practical applications,due to the long pipe network and the difference of the distributed distance,the design of heat-exchange station automatic control system applies the distributed pump control system.In this method,it can preliminary balances the distribution of hydraulic and thermal power of pipe network.Eventually,by applying a heat-supply company of Xinjiang Urumqi City as a platform of the heat-supply network monitoring system,this project achieves to monitor totally 77 sites under this heat-supply company and 102 heat-exchange automatic control stations’ self-control operation units.Through the operation effect of 2015 heating season,the system runs stably and meets the demand of energy saving management of the heat-supply company.