Study On Remote Monitoring System Of Non-pipeline Natural Gas

With the deepening of the environment-protecting awareness,the demand of natural gas as green energy is also increasing,which poses a great challenge to natural gas storage and transportation.For small and medium-sized cities and small-scale users,the initial laying pipelines cost too much.Therefore,transport natural gas with non-pipeline way has become a practical solution to the gasification in small and medium-sized cities.Natural gas stations and tankers,as important nodes in transporting natural gas with non-pipeline,are responsible for the safe and stable supply of natural gas.In order to ensure the safe and reliable operation of gas stations and tank trucks,and to operate accurately,it is of great significance to study the remote monitoring system for the non-pipeline natural gas.Therefore,this paper aims at the actual needs of data acquisition and equipment monitoring in the process of the non-pipeline natural gas storage and transportation,and studies and designs a remote monitoring system for the non-pipeline natural gas.At first,based on the technological process of LNG gasification station and combining with the actual requirements of monitoring system,this paper proposes the overall framework of the monitoring system.It consists of monitoring center,monitoring station and GPRS network.Monitoring center is responsible for data collection,archiving,display,statistics and reporting work,and user can view and operate through the visual interface.Each monitoring station has PLC(Programmable Logic Controller)and data transmission terminal,PLC collect equipment's real-time data,data transmission terminal sent the data to monitoring center.GPRS network is the way of data transmission.At the same time,this paper analyzes the reasons for choosing MQTT protocol as the transmission protocol.Secondly,this article describes the data transmission terminal design.Hardware,the terminal uses LPC1768 as the main chip,using ublox SARA-G350 as a GPRS module.Software,the terminal choose mbed as development platform,Keil MDK as development environment,also introduced the overall framework of the terminal program.Then,in view of the problems in the remote monitoring system of the non-pipeline natural gas,this paper studies the key technologies designed and implemented to solve these problems: 1)Solve the problem of natural gas station differences through a configurable data acquisition scheme;2)Implements the data transmission with MQTT protocol;3)Solve the remote maintenance problem by implementing remote code update and remote PLC code update;4)Solve the data loss problem through the SD card storage and retransmission mechanism.Finally,this paper apply remote monitoring system for the non-pipeline natural gas to monitor liquefied natural gas gasification station and tank truck equipment,and a LNG information management system is set up to verify the practicability and effectiveness of the system.Meanwhile,this paper realizes the automatic analysis of the historical data while monitoring the on-site equipment,carries on the fault diagnosis to the equipment,reports the fault in time.