(161b) Incorporating Reliability, Availability and Maintainability (RAM) into Process Synthesis

This work presents a new approach to bring together process syntheses and RAM analysis into one systematic optimisation framework for the purpose of process conceptual design. In the model, Weibull distribution is used to present the failure modes, and the frequency of preventive maintenance is optimised in order to maximize the process availability and minimize the overall cost. Firstly, the concept of Reliability Block Diagram Superstructure (RBDS) is introduced, which contains the reliability information of the process synthesis superstructure, in terms of process inherent logical connections. RBDS builds a bridge between process synthesis and RAM analysis, and enables us to integrate RAM into process synthesis. Secondly, RAM Model is developed to incorporate process reliability, availability and maintainability features into the general optimisation framework by reflecting the impact of preventive maintenance on equipment reliability. The optimal process conceptual design is then obtained from all feasible options by considering the trade off between capital investment and operation costs through whole plant life cycle.