Deterministic Flexibility Analysis

Book excerpt: Traditionally, design and control decisions are made in sequential stages over the life cycle of a chemical plant. In the design phase, the optimal operating conditions and the corresponding material and energy balance data are established mainly on the basis of economic considerations. In the subsequent step, the control systems are configured to maintain the key process conditions at the fixed nominal values. Because it is often desirable to address the operability issues at the earliest possible stage before stipulation of control schemes, the systematic incorporation of flexibility analysis in process synthesis and design has received considerable attention in recent years. This book focuses to a large extent on computation and implementation methods of deterministic performance measures, i.e., the steady-state, volumetric, dynamic and temporal flexibility indices, in various applications. The formal definitions of several available performance indices, their mathematical formulations, and the corresponding algorithms and codes are provided in sufficient detail to facilitate implementation. To show the utility of flexibility analyses, the book presents several practical case studies including membrane modules and heat-exchanger networks, solar-driven membrane distillation desalination systems, and hybrid power generation systems. It also includes MATLAB and GAMS codes.