The Research And Design Of The Monitoring System For Coal-Bed Methane Power Generation Process Based On S7-300 PLC

Coal-bed methane is a practical, economical and environmental energy, its comprehensive development and utilization will play a major role in the national economy constructing and adjustment of energy structure. With the growing of China's electrical energy demand, utilization of coal-bed methane in power generation has drawn increasing attention.Many parameters(such as coal-bed methane temperature, coal-bed methane pressure, coal-bed methane concentration and generator speed ) need to be monitored in the process of coal-bed methane power generation. Safe and reliable methods must be adopted to detect and control these parameters to ensure the safe and stable operation of the system. In order to improve the efficiency of energy utilization sufficiently, reduce the labor intensity of workers, and improve the management level of information in the enterprise, a set of supervisor and control system with enough safety, liability and high efficiency which can guarantee the coal-bed methane power generation's automation is very necessary. Based on a coal-bed methane power plant, this article researched and designed a process monitoring system of coal-bed methane power production based on the S7-300 PLC,achieved real-time monitoring on the process of coal-bed methane power generation in conjunction with various detection sensors.The paper first introduces the background and significance of the research, describes the coal-bed methane power generation process and equipment selection in detail. According to the actual requirements of conditions and process equipments, the control system hardware and software configuration was studied and selected. With the principles of safe, reliable, advanced, economic, practical, open and good, adopting SIEMENS S7-300 PLC as the Core controller, using software redundancy scheme, combined with PROFIBUS-DP field bus technology, all control equipments on-site were constructed of small-scale distributed monitoring system.According to the characteristics of coal-bed methane production technology,the paper focused on the design of coal-bed methane main pipeline in carrier stage and generator monitoring system.The control core in the coal-bed methane transport stage is the pressure regulation.This paper adopted PID control method to achieve the pressure regulation in coal-bed methane pipeline through the inverter controlling booster fan.Coal-bed methane generator monitoring system achieved the collection of the analog parameters, treatment and control of generator speed.Consider of the safety and stability of coal-bed methane power generation production,a series of security measures were adopted to ensure the safe operation of coal-bed methane power generation.In addition, S7-PLCSIM simulation tool was used for simulating sequence control of coal-bed methane main pipeline in the transport stage and generator system, the results showed that the design of the sequence control is correct and feasible.