Fouling　is　a　crucial　problem　in　refinery　HEN　(heat　exchanger　network)　that　reduces　heat　transfer　and　affects　regular　production.　The　conventional　way　to　mitigate　fouling　is　cleaning　heat　exchanger　regularly　or　improving　operation　conditions,　but　simultaneous　consideration　of　the　two　methods　is　rare.　This　paper　presents　a　combined　approach　for　mitigating　fouling　in　HEN　by　optimizing　operation　condition　and　cleaning　schedule　simultaneously.　For　optimization　of　operation　condition,　flow　velocity　is　selected　as　a　key　variable　since　it　can　correlate　fouling,　heat　transfer　and　pressure　drop.　An　overall　optimization　of　network　performance　can　be　achieved　through　redistribution　of　velocity.　In　a　refinery　HEN,　fouling　cannot　be　completely　prevented　through　optimization　of　operation　conditions,　so　management　of　cleaning　actions　is　optimized　to　deal　with　the　remained　fouling.　SA　(Simulated　annealing)　algorithm　is　used　in　this　work　to　obtain　a　comprehensive　strategy　for　mitigating　fouling.　The　application　of　the　proposed　method　is　demonstrated　using　a　case　study.　The　results　show　higher　energy　saving　and　economic　efficiency　compared　with　existing　methods.　(C)　2016　Elsevier　Ltd.　All　rights　reserved.