Expansion　refrigeration　can　obtain　relatively　larger　temperature　drop,　and　it　had　the　potential　of　utilization　on　industrial　energy　saving,　such　as　cryogenics　air　separation,　light　hydrocarbon　recovery,　expansion　valve　replacement　and　mine　cooling,　etc.　At　present,　lots　of　large-scale　gas　expansion　refrigeration　systems　have　been　applied　in　many　industrial　fields.　In　many　actual　industrial　processes,　there　were　tremendous　demands　for　small-scale　gas　expansion　refrigeration　units.　However,　those　systems　didn＇t　realize　commercial　application　due　to　technical　and　economic　bottleneck.　So　research　and　development　small-scale　reverse　Brayton　cycle　refrigeration　system　was　very　important　to　energy　conservation　and　emission　reduction　for　our　country.　In　this　paper,　a　typical　process　of　reverse　Brayton　cycle　refrigeration　system　was　presented　and　the　thermodynamic　model　was　established,　the　influence　factors　of　internal　heat　exchanger　and　the　adiabatic　efficiency　of　expanders　were　analyzed.　From　the　simulation　result,　it　was　concluded　that　internal　heat　exchanger　couldn＇t　improve　the　coefficient　of　performance　for　entire　system,　but　could　decrease　the　outlet　temperature　of　expander　efficiently.　With　the　increase　of　reheat　temperature　difference,　the　effect　of　reheat　reduced.　Those　works　can　provide　the　theoretic　basis　to　study　on　small-scale　reverse　Brayton　cycle　refrigeration　system.　©　All　Rights　Reserved.