Axial-flow reversible turbine

摘要

An axial-flow reversible turbine comprises a nozzle assembly and a wheel rotor mounted consecutively in the direction of the flow of the working medium and provided with two-section blades. One section of said blades forms the flow duct of the direct-rotating turbine and the other section, the flow duct of the counter-rotating turbine. The flow duct of the direct-rotating turbine incorporates a valve in the form of variable-incidence airfoil vanes intended to deny the access of the working medium into said duct. The inside diameter of the flow duct of the counter-rotating turbine is larger than the outside diameter of the flow duct of the direct-rotating turbine. The gas flow ducts of the direct- and counter-rotating turbines communicate with each other through a cylindrical bushing with ports. Said bushing is installed coaxially with the wheel rotor at the inlet of the flow into the flow duct before the nozzle assembly and its inside diameter is substantially equal to the outside diameter of the flow duct of the direct-rotating turbine. The bushing is provided with a band arranged along its periphery and being sufficiently wide for overlapping the ports. The band has a device for moving it radially to at least two fixed positions in one of which it fits around the outside circumference of the gas flow duct of the counter-rotating turbine and in the other position it fits around the outside circumference of the gas flow duct of the direct-rotating turbine.