Energy-integration
methods for process systems such as Heat Exchanger
Network Synthesis (HENS) and Work-Heat Exchanger Network Synthesis
(WHENS) have been developed to promote energy conservation and reduce
emissions in process systems. The proper integration of compression
heat and HENS with multiple utilities instead of a single-level utility
facilitates improving energy utilization. This paper introduces an
extended superstructure-based model for the synthesis of a compression-heat-integrated
heat exchanger network coupled with multiple utilities. The superstructure
optimizes both heat exchange matches and the usage of high-, medium-,
and low-pressure steam levels generated by the utility system. Compression
heat for certain streams is also optimized to explore the interaction
of compression work and utility consumption. A mixed-integer nonlinear
programming model is established to simultaneously minimize the total
annualized cost and exergy consumption. To demonstrate the feasibility
of the proposed model, an example with two cases is investigated,
indicating that compression heat can significantly improve heat recovery
and energy efficiency.