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 superstructurebased 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.