A　three-dimensional　model　of　the　steam　ejector　heat　pump　for　the　dryer　section　of　the　paper　machine　was　developed　by　applying　the　Computational　Fluid　Dynamics　(CFD)　technique,　which　provided　the　pressure　and　velocity　distributions　of　fluid　flow　in　heat　pump.　The　results　indicated　that　the　fluid　velocity　field　in　heat　pump　has　an　incomplete　axially　symmetrical　distribution.　The　entrainment　ratio　of　the　heat　pump　initially　increases　rapidly　with　the　increase　of　the　ejected　steam　inlet　pressure　and　then　decreases　after　the　inlet　pressure　exceeds　one　certain　value.　There　exists　a　critical　value　for　the　mixed　fluid　pressure　under　the　given　operating　conditions.　The　optimal　ratio　of　the　diameter　of　constant　area　mixing　section　to　the　steam　nozzle　throat　diameter　is　about　3.4　and　the　optimal　ratio　of　length　to　diameter　of　constant　area　mixing　section　L/D-m　is　6.　An　optimal　divergence　angle　of　diffuser　was　observed　under　different　diffuser　length.　There　is　an　optimized　steam　nozzle　position　under　the　given　operating　condition　where　the　maximum　of　entrainment　ratio　was　observed.　The　CFD　technique　is　found　to　be　an　efficient　alternative　to　predict　the　ejector　performance　and　the　conclusions　of　the　research　can　provide　a　beneficial　reference　for　structural　optimization　design　of　ejector.　(C)　2015　Elsevier　Ltd.　All　rights　reserved.