Efficient　heat　conversion　of　low　temperature　heat　source　is　a　key　problem　for　energy　saving,　especially　in　the　fields　of　waste　heat　recovery　and　renewable　energy　utilization.　At　present,　technical　bottleneck　for　low　temperature　thermal　power　is　lack　of　suitable　prime　mover.　As　the　core　component　of　general　machinery,　single　screw　has　many　good　features,　including　balanced　loading　of　the　main　screw,　low　leakage,　low　noise,　low　vibration　and　long　working　life,　etc.　If　single　screw　technology　is　applied　to　the　field　of　expander,　more　efficient　prime　mover　would　be　possibly　obtained,　compared　with　pistol　expander,　scroll　expander　and　twin　screw　expander,　and　so　on.　In　order　to　verify　the　performance　of　the　prototype,　the　function　experiment　was　made.　In　this　paper,　compressed　air　was　used　as　working　fluid　and　performance　test　for　the　prototype　was　finished　at　conditions　including　different　intake　flow,　different　humidity,　constant　torque,　and　constant　rotational　speed.　From　the　experimental　data,　it　is　shown　that　the　power　output　is　5　kW,　exhaust　temperature　is　-45　degrees　C,　difference　between　the　import　and　export　is　about　62　degrees　C,　in　the　conditions　of　inlet　pressure　at　0.6　MPa　and　rotational　speed　2850　rpm.　The　test　results　also　show　that　the　single　screw　expander　has　good　part　load　characteristics.　From　the　analysis　of　experimental　data,　we　found　that　adiabatic　efficiency　of　the　prototype　is　not　so　high　probably　because　of　poor　lubrication.　The　lubrication　problem　will　be　considered　in　the　next　work.　Crown　Copyright　(C)　2011　Published　by　Elsevier　Ltd.　All　rights　reserved.