Compared　with　conventional　steam　boilers,　slightly-pressurized　submerged　combustion　evaporator　is　advantageous,　which　is　in　the　absence　of　a　heat　transfer　surface,　with　higher　efficiency　of　heat　transfer　and　lower　emission　of　pollutants.　Pressurized　submerged　combustion　evaporator　(PSCE)　reported　in　this　paper　is　its　extension　to　high　pressures　and　temperatures.　Based　on　the　first　law　of　thermodynamics　and　with　the　consideration　of　energy　consumption　of　compressors　in　PSCE　and　fans　in　steam　boiler,　the　PSCE　is　compared　with　the　steam　injection　boiler　under　the　same　condition.　For　8-21　MPa　steam,　although　the　energy　consumption　of　compressors　constitutes　a　large　proportion　of　the　whole　energy　consumption　in　PSCE,　the　heating　efficiency　is　high　and　the　heat　recovery　of　PSCE　is　effective.　The　energy　saving　rate　of　PSCE　is　estimated,　which　is　usually　6%-12%.　The　results　show　that　PSCE　has　a　greater　potential　for　energy　saving　than　steam　boiler.　©　All　Rights　Reserved.