Design And Inplementation Of Distributed Monitoring And Control System For Heating Network

With the swiftly developing of national economy, urban central heating scale in china is expanding continuously. The main problem for heat-supply enterprise is how to monitoring-controlling manage the running position of the heat-supply network efficiently to improve heating quality and cut down energy consumption. From engineering design's point of view, technical requirements, overall plan, equipment selection, and system function of the monitoring system for heat-supply network have been researched in this paper, and a set of completely solutions are provided.Based on analyzing the current situation of centralized heating at home and abroad and balance control mode of heat-supply network, the major problems of monitoring heat-supply network are summarized, then, the research framework, research target, research program of this paper are proposed. The process conditions and the requirements for controlled heat-supply network are analyzed in detail. Depending on the comparison of the controller and the realities of the engineering situation, the PLC system of Siemens is selected as the master controller of the heat exchange station. The structure and function of the system are proposed and discussed in detail. The structure adopts the hierarchic arrangement. The functions include data acquisition and processing, analogy control, and sequence control. Based upon above functions, the functions, such as automatic controlling the system, centralized monitoring production process and device status, and automatic alarm are achieved.Advantages and disadvantages of the common communication for heat-supply network are analyzed comparatively. The communication of dial-up which is based on PSTN is selected according to the need for heat-supply network controlling and practical engineering. The overall structure of the monitoring system for heat-supply network is provided. Network components, network structure, and implementations of the heat-supply network monitoring center and the heat exchange station are represented. The data exchange between monitoring system and the monitoring center for heat-supply network is implemented to ensure that the running of monitoring system for heat-supply network and the unit control system can be coordinated.The operational mechanism and influencing factors of the heat-supply network technology system are analyzed. The controlled object is nonlinear, long delay and strong coupling. In response to above features, the algorithms of the heat balance control of the network are researched. The temperature of circulating pump and backwater is controlled by neural network and incomplete differential PID control scheme to adjust heat balance of the heat-supply network. It can not only keep the control accuracy but also enhance the response speed. The heat-supply network engineer has achieved the desired results by debugging the monitoring system for heat-supply network, and the heat-supply efficiency is increased.