Work and heat exchange network synthesis considering multiple electricity-related scenarios

Abstract

Work and heat integration has emerged in the last decade as a promising area with a wide scope for research. Under that relatively new field, the synthesis of work and heat exchange networks (WHEN) is certainly an encouraging subject. This work presents a method for WHEN synthesis considering some aspects that were not approached in previous literature. Multiple electricity cost scenarios are considered and analyzed in the synthesis task. These are proposed according to different electricity production regimes, which are used by suppliers due to eventual changes in electricity production conditions (e.g., low level in hydroelectric power plants reservoirs). Evidently, monthly electricity prices are affected under such regimes. In the model, multiple utilities use is possible. Utilities can be modelled as regular process streams (instead of the typical approach of fixed inlet/outlet temperatures in heaters/coolers). The model also comprises the use of piecewise linear approximations for enthalpy/temperature calculations. The solution approach is an enhanced meta-heuristic method. It could be observed that considering an intermediate electricity cost scenario (between optimistic and pessimistic predictions) for the WHEN synthesis stage may lead to smaller monetary losses in case of occurrence of other scenarios.