标题:Simulation and Design Methods for Multiphase Multistream Heat Exchangers * * The authors are grateful to Statoil for providing financial support for this research.
摘要:Multistream heat exchangers (MHEXs) are found in many energy intensive and industrially relevant cryogenic processes. However, design and optimization of such processes is rendered difficult by the inability to simulate MHEXs robustly as most current flowsheet-level MHEX models solve only an energy balance with no constraint on second law feasibility The new model described herein combines an extension of the classical pinch analysis algorithm with explicit dependence on the heat exchange area to formulate a nonsmooth equation system which can be solved for up to three unknown variables in an MHEX. The resulting model is further augmented to simulate realistic thermodynamic phenomena, such as phase change and equilibrium, which are also naturally described by additional nonsmooth equations.