Design Of Natural Gas Station Monitoring System And Software Implementation

Natural gas station is an important node in the natural gas transmission and distribution system. Natural gas station will do current limit, voltage regulator, filter treatment on natural gas from long pipeline, then as a gas source, to provide a safe, stable and clean natural gas supply for the majority of residents. Meanwhile, the task of natural gas flow measurement is undertaken by natural gas station. For the trade interests of both, the high accuracy of flow metering is required. In this paper tries a natural gas station monitoring system is developed to meet the high accuracy and real-time requirements of natural gas station flow metering and monitoring.This paper aims to adopt ForceControl V7.0, flow computer and PLC to design and develop a new natural gas station monitoring system to update the old one in Sichuan. Based on the typical production process of natural gas station, the requirements of the monitoring system are analyzed in this paper first. Then the overall structure as well as the hardware and software integration solutions is worked out in this paper. Lower computer system can be divided into two parts flow metering unit and valve control unit. The structure of the valve control unit is designed in this unit. And the I/O signals of this unit are completely analyzed in the unit. In order to achieve the high reliability of monitoring system, a redundant structure is needed. Siemens PLC can use PID to control electric valve, and then adjust the pressure or flow of the pipeline automatically. The flow monitoring software in the upper machine is the focus of this paper. The developer can develop a fully functional, stable performance monitoring software rapidly with the assistance of ForceControl. In the flow monitoring software, Modbus/TCP protocol is used to communicate with flow computer and PLC over industrial Ethernet network. And a good user interface is provided to monitor natural gas station’s production process, real-time data, devices status or other information, and set devices’parameter in the software. Moreover, real-time data is dumped into SQL Server periodically. In this software, users can inquiry historical data, trend curves, and statistical reports, then print the results out. When the natural gas station encounter abnormal situation, the software will alert the user, and record alarm and event information.Finally the flow monitoring software has been tested well. Overall, the system has achieved the design objective, and can meet the monitoring demand of small-scale natural gas station.