The hydrogen system has become an important component of the refinery with the increasing demand of hydrogen.It is significant for the optimization of the hydrogen network to realize the minimization of economic objectives and stable operation under all the operation conditions.A flexible optimization strategy is proposed based on the varying operation conditions and demand of hydrogen system in refinery.A mixed integer nonlinear programming(MINLP)model is formulated to optimize the hydrogen network under multi-scenarios.Then the MINLP model is linearized and solved with Lingo software.A case study based on the data from a refinery is showed to demonstrate the effectiveness and feasibility of the presented flexible optimization strategy.The comparison between the proposed strategy and the original hydrogen network shows that the presented flexible optimization strategy has better flexibility

and significant savings and stable operation of hydrogen system is realized.The proposed strategy plays an important role in guiding the management of hydrogen system in refinery.