Heat exchanger network synthesis integrated with flexibility and controllability

Over the last three decades, flexibility and controllability considerations for heat exchanger networks (HENs) have received great attention, respectively. However, they should be simultaneously incorporated in HEN synthesis to allow the economic performance to be achievable in a practical operating environment. This paper proposes a method for simultaneous synthesis of flexible and controllable HEN by considering their coupling. The key idea is to add the bypasses with optimized initial fractions and positions to explore such coupling, and consequently enabling HENs to be operated successfully over a range of disturbance variations. These are implemented by identifying and quantifying disturbance propagations, and then examining the sensitivity of bypasses to the entire HEN. In this way, the superstructure-based mixed integer non-linear programming (MINLP) with objective function of minimizing the total annual cost is formulated. A case study is used to demonstrate the application of the proposed method. Quantitative measures and dynamic simulation show the ability to provide the satisfactory flexibility and controllability of the obtained HEN. (C) 2018 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights reserved.