Multi-objective Optimization of Sustainable Single-Effect Water/Lithium Bromide Absorption Cycle

A rigorous mathematical approach is developed for optimization of sustainable single-effect water/Lithium Bromide (LiBr) absorption cooling cycles. The multi-objective formulation accounts for minimization of the chiller area as well as the environmental impact associated with the operation of the absorption cycle. The environmental impact is quantified based on the global warming potential and the Eco-indicator 99, both of which follow principles of life cycle assessment. The design task is formulated as a bi-criterion non-linear programming problem, the solution of which is defined by a set of Pareto points that represent the optimal compromise between the total area of the chiller and global warming potential. These Pareto sets are obtained via the epsilon constraint method. A set of design alternatives are provided for the absorption cycles rather than a single design; the best design can be chosen from this set based on the major constraints and benefits in a given application. The proposed approach is illustrated design of a typical absorption cooling cycle.