Abstract: This paper studies the application of Aspen Flare System Analyzer in the design of flare net for synthetic ammonia units in natural gas chemical industry. The technical terms related to the design of flare net for chemical plants are introduced, the calculation method, modeling design principle and application scope of Aspen Flare System Analyzer are discussed, and the design of a flare system in an ammonia unit is analyzed. The results show that a diameter of piping should be given by experience before using the Aspen Flare System Analyzer, and choosing the rating mode would obtain a more reasonable size of the flare net and improve the design efficiency of flare net

Key words: Flare net, Aspen Flare System Analyzer, Back pressure, Mach number