Effect of metal honeycomb structure on enhancing CHF in saturated downward-facing flow boiling

•The effect of hole diameter, pitch and hole diameter/pitch ratio of the metal porous honeycomb plate on flow boiling CHF was investigated.•The reduction in boiling area has a big influence on downward-facing flow boiling CHF.•Additional water supply through the metal porous media has significant CHF increase effect for some kinds of honeycomb plate.