New procedure for design and exergoeconomic optimization of site utility system considering reliability

An examination is reported of the effects of equipment reliability on the exergoeconomic analysis and optimization of a site utility system. A new procedure is proposed that incorporates a hybrid method that has several advantages over the commonly used approach. The steam network design has a significant impact on the utility system, and the availability of steam mains is taken into account. An analysis of the availability of system components identifies components that can affect system operation. For this purpose, the state-space and the continuous Markov methods are incorporated in thermoeconomic analysis to improve the economic costs. Additionally, the design and optimization of utility systems potentially involve a large number of alternatives that, if properly designated, can yield significant savings in total costs. In this regard, the proposed new procedure addresses the optimal design of site utility systems. Tools applied to assist process integration include total site analysis, site utility grand composite curves (SUGCCs), the cogeneration targeting method and exergoeconomic analysis. Furthermore, multi-objective exergoeconomic optimization is performed using a genetic algorithm based on hybrid techniques in order to determine optimum solutions. The applicability of the proposed procedure is tested using STAR® software through a case study for grassroot problem.