Research On Automatic Monitoring System Of Gas Pressure Regulating Station

With the rapid social development, natural gas has already entered into many areas ranking the third place after coal and petroleum in natural energy resources because of being high efficient and environment-friendly. Natural gas becomes available to clients only after it is regulated through multi-stage pressure stations. As a node in the whole natural gas regulating chain, natural gas pressure regulating station plays a very important role. The automation level of natural pressure regulating station signifies the modernization level of municipal gas industry. Therefore, to establish a natural gas regulating station automatic monitoring system is of great significance to the development of municipal gas industry.Based on the comprehensive background of municipal gas industry, a gas regulating station automatic monitoring system has been studied as follow in this paper. Firstly, based on the investigation and evaluation to the present status of a gas regulating station located in Lezhi County, Sichuan Province, an overall automatic controlling scheme has been determined for the technical improvement and systematic upgrade with Siemens PLC’s plus PC machines, in which PLC’s are applied as centered controlling parts while transducers (such as pressure transducers, temperature transducers and etc.), as detecting elements, electromagnetic valves to switch on and off and pneumatic pressure-regulated valves to adjust pressure, as actuators and WINCC, as monitoring interface. For the practice of the scheme, it is necessary to pay much more attentions to those field instruments including transducers, electromagnetic valves pressure-regulated valves and etc. with high performance-cost ratios. Secondly, to overcome the difficulty of gas pressure control, controlling strategies has been adopted based on parameter self-tuning fuzzy PID hereby as well as fuzzy PID controller has been designed relevantly. Based on the constructed mathematical model for the controlled object, simulation work has been done for the whole pressure controlling system, which proves that the after-valve pressure can be easier to regulate and become more stabilized. Finally, a monitoring system for the gas pressure regulating station has been designed, in which hardware selection and software programming for PLC control and PC interface are included. Designed fuzzy PID controller has been validly applied to PLC by exchanging data between MATLAB and PLC with OPC technology. A real-time gas pressure regulating station monitoring system has been successfully set up to work through systematic debugging.