The　liquid　evaporation　process　in　a　nanoporous　medium　under　the　influence　of　noncondensable　gasses　is　a　fundamental　problem　in　energy　and　chemical　engineering.　Based　on　the　kinetic　theory　of　gasses　and　the　moment　method　for　the　Boltzmann　equation,　the　flow　resistance　of　vapor　in　nanoscale　pores　or　channels　was　analyzed,　and　a　theoretical　model　for　the　single-component　evaporation　problem　was　proposed.　Further,　direct　simulation　Monte　Carlo　was　performed　to　study　evaporation　in　the　presence　of　noncondensable　gasses.　An　empirical　correlation　was　established　to　predict　the　liquid　evaporation　rate.　The　results　showed　that　nanoporous　evaporation　can　be　divided　into　three　parts:　vapor　flow　within　the　nanopore　or　channel,　kinetic　expansion　out　of　the　nanopore,　and　convection-diffusion　flow　of　vapor　downstream.　The　porosity　and　aspect　ratio　of　the　vapor-occupied　pore　section　have　a　profound　influence　on　the　evaporation　rate.　Moreover,　the　effect　of　noncondensable　gas　is　more　outstanding　at　larger　porosities　than　at　smaller　porosities.　The　liquid　evaporation　rate　can　be　reduced　by　50%　when　the　vapor-occupied　pore　section　has　an　aspect　ratio　of　2.5.　The　model　of　single-component　evaporation　combined　with　the　empirical　correlation　for　dimensionless　evaporation　rate　can　predict　direct　simulation　Monte　Carlo　results　within　10%.　©　2024　Chinese　Academy　of　Sciences.　All　rights　reserved.