LAST STAGE OF TURBINE Russian patent published in 2007 - IPC F01D11/02 

FIELD: mechanical engineering; turbines.

SUBSTANCE: proposed last stage of turbine contains guide vane assembly, nozzle blades, turbine wheel, diaphragm body and labyrinth seal of turbine shaft, and surfaces limiting flow path. Suction chamber with nozzles or diffusers at inlet is made in root zone of stage in diaphragm body. Said nozzles or diffusers are arranged uniformly over circumference on root limiting surfaces of flow path at trailing edges of nozzle blades. Suction chamber is connected with pressure charging chamber made in diaphragm body by adjoining channels so that its upper wall adjoins root limiting surface of guide vane assembly. Airfoil cascade with outlet angles greater than or equal to corresponding angles of guide vane assembly in root section is installed at outlet of pressure charging chamber. Root limiting surface of cascade is orientated so that radius at outlet equal to radius of root limiting surface at inlet of turbine wheel.

EFFECT: increased efficiency of last stage of steam turbines by improving stability of flow in last stage.

1 dwg