M-LNG Skid-mounted Liquid Based On PLC Systems Research And Development

The resources of Natural gas is widely distributed in China, The distribution trends of geographical is more in the west and less in the east. most of them are small discrete field, is located in the remote area, the gas production rate of single well is low, so the recoverable gas resources will not be fully utilized. In recent years, In order to make full use of these resources, the M-LNG has advantages in fileds of flexible mobile, easy take apart and install, small volume, short build period, it is will be got a lot of attention. Therefore, this paper using automatic control technology, witn the professional knowledges of physical and chemical properties and production of natural gas, I carried on the deep comprehend about this device and key implementation technology, the Smart SIEMENS S7-200 PLC as the core, to develop the corresponding automation control system, the main contents as follows.First of all, Analyzed the design of LNG equipment and liquefaction processes, on the basis of complete small portable LNG Skid mounted process design, and according to the natural gas liquefaction process and production information, as well as LNG Skid-mounted station the station control system needs, small M-LNG Skid-mounted station control system architecture. On this structure, planning station control system hardware, complete the on-site equipment units of various types of instrument selection, process control units of the main wiring design of hardware and hardware selection, software design of monitoring and management unit.Then, the poor working conditions for gas field and skid-mounted production information characteristics of large amount of data is presented based on Ethernet Network data exchange program, which has taken two sets of communication lines, one TCP/IP Agreement, accomplished through the Ethernet interface between PC and PLC, PLC PLC And between PLC Communication with slave and another is to use a wireless router to achieve real-time data exchange between control system and monitoring system.Finally, according to the control station control system requirements complete PLC Software programming of the control unit, and MATLAB Simulation software PID Control simulation, complete PC based on kingview Smart 700IE creation of lower computer monitor screen, complete the Modbus RTU Slave Protocol communication protocol written Realization of small LNG Development of skid-mounted station control system and application testing confirmed the applicability of the system.