Research On Automatic Adjustment Of The Component Of Refrigerant For The Liquefied Natural Gas

This paper researches how to realize automatic control of refrigerant gas mixtureliquefaction process. According to the process of active ZHUHAI liquefied naturalgas plant, briefly introduces the working principle in natural gas liquefaction processmixed refrigerant composition structure, the existing control methods and the mixedrefrigerant existing manual adjustment of the foundation. The expert control system isestablished based on the theory of expert control system to realize the automaticcontrol of mixed refrigerant components. Then use MATLAB simulation software tosimulate actual working conditions, study the control ability of the automatic controlsystem. Artificial control and Simulation of the control system to control the output iscompared under the same conditions, found the automatic control system can simulatemanual control and can adapt to more complex conditions. At the same time, based onthe artificial regulation of mixed refrigerant composition control loop, increase thecontrol valve and flow meter, constructed the mixed refrigerant composition closedcontrol loop of automatic adjustment, according to the process and data research andthe relevant examples introduces the selection of flow meter and control valve. Finally,analysis of the automatic control economic advantage, such as liquefied natural gasproject in the future implementation of mixed refrigerant group laid a theoreticalfoundation for the design and optimization of automatic control system.The main research contents of this paper are: Construction of liquefied natural gasin the process of mixed refrigerant composition control loop automatic regulation;Meet the requirements of liquefied natural gas for refrigerant flow measurement meterresearch and selection; Meet the requirements of liquefied natural gas for flowregulation and control valve research and selection; Automatic control design ofliquefied natural gas refrigerant automatic regulation; Through the MATLABsimulation process, analysis reliability and feasibility study on automatic controlprogram, and draw a conclusion.