Utility Exchanger Network synthesis for Total Site Heat Integration

Abstract

Total Site Heat Integration (TSHI) targeting and optimisation methods have been well developed while few studies deal with detailed Utility Exchanger Network (UEN) design. The UEN is the network of heat exchangers that connect a site’s centralised utility system to provide the required process heating and cooling while also facilitating inter-process heat recovery, i.e. TSHI. This paper presents a new UEN design procedure based on the recently developed Unified TSHI targeting method. The Unified method applies more strict constraints on the UEN network, compared to Conventional methods, allowing series utility exchanger matches for a non-isothermal utility if the exchangers in series are from the same process. This constraint reduces the dependency of the individual processes that constitute the Total Site. In UEN design procedure based on the Unified method, calculated utility targets can be archived after UEN design and the number of exchangers reduces compared to the Conventional methods’ design procedure. Also, different Exchanger Minimum Approach Temperature in the UEN synthesis may have an influence on network design and the exchanger configuration but the identical heat recovery and utility targets are achieved after UEN design based on both design procedures.