Development of Site-wide Energy Strategies
Pinch Analysis has been applied to individual processes routinely since the early 1980s. The composite curves of the process define the minimum heating and cooling demands while the grand composite curve further illustrates how the heating and cooling is best applied, utility level by utility level. One of the many specific benefits of this technique is therefore to identify the most appropriate types and temperature levels of heating utility for any particular process. In the early 1990s, techniques and software were developed to extend the single plant analysis across entire sites in a systematic way. This new Total Site™ analysis identifies the optimum site utility structure necessary to support the several individual processes. In particular, the site hot utility demand can be optimised thereby maximising cogeneration and minimising fuel-related emissions. Minimum energy demands of the whole site can be determined but, more importantly, the technique allows choices to be made between individual process optimisation and site infrastructure improvements. In this way, a consistent “Road Map” of site improvements can be developed to define an investment strategy for the site. This paper describes the techniques of Total Site™ analysis and shows examples of Road Maps developed for major clients world-wide.