Formulating an Optimization Problem for Minimization of Losses due to Utilities

Utilities, such as steam and cooling water, are often shared between several production areas at industrial sites, and the effects of disturbances in utilities could thus be hard to predict. In addition, production areas could be connected because of the product flow at the site. This paper introduces a simple modeling approach for modeling the relation between utility operation and production. Using this modeling approach, an optimization problem can be formulated with the objective to minimize the economical losses due to disturbances in utilities by controlling the production of all areas at a site. The formulation of the problem is general, and thus the optimization can be performed for any site with similar structure. The results are useful for investigating the impact of plant-wide disturbances in utilities, and can provide decision support for how to control the production at utility disturbances. To enable online advise to operators on how to control the production, the posed optimization problem is solved in receding horizon fashion.