The Application of Advanced Process Control on Gas and NGL Plants

摘要

While the use of multivariable predictive control in midstream gas and NGL plants is new, the technology has been used in the refining and petrochemical industries for more than 15 years. This paper explains the key features of a controller; namely: 1.Multivariable - all the key variables of the plant are included in the controller scope 2.Predictive - the controller will predict how the key variables will behave 3.Optimization - the controller will drive the plant to the most economical state and hold it there 4.Constraint handling - the controller will honor all the plant constraints 5.Closed loop - the controller will implement the optimized setpoints without human intervention.Each of these features are discussed individually, and then as a whole. How benefits are achieved using multivariable control and the effects of pigging, ethane recovery/rejection, and plant reliability benefits are fully explained. Finally, a typical controller design and project methodology is presented.