Patent ID: 6533546
Filing Date: 2003-03-18
Classification: F01D

Abstract:
An axial/radial three-channel diffuser with an exhaust steam housing for a low pressure steam turbine, which guides the blade exhaust steam into the exhaust steam housing, the diffuser comprising an inner diffuser ring, an outer diffuser ring, and two guide vanes that divide the diffuser into an inner partial diffuser, a middle partial diffuser, and an outer partial diffuser,the inner diffuser ring being arranged in relation to a hub of the low pressure steam turbine at an inflexion angle (&thgr;N), and the outer diffuser ring in relation to a last partial piece of a blade carrier of the low pressure steam turbine at an inflexion angle (&thgr;Z), wherein the two guide vanes extend over the entire length of the diffuser, and the two guide vanes are distributed between the inner diffuser ring and the outer diffuser ring in such a manner that the surface areas over the three partial diffusers in the inlet surface area is different, a majority of the flow inlet surface area of the diffuser overall is part of the inner and middle partial diffuser, and a small part of the flow inlet surface area of the diffuser overall is part of the outer partial diffuser, wherein starting tangents of the guide vanes, together with the limits of a last stage blade channel on the hub side and on the housing side that approximate each other in a straight line, form an at least approximately common intersection point (A).