BLOCKING ELEMENT FOR ROTOR WINDING HEADS ON TURBOGENERATORS WITH ROTOR CAP WITH RADIAL VENTILATION BORES

Abstract

A blocking element for a rotor head winding of a turbogenerator has a form which is adapted to the contour of the adjacent conductor of the rotor head winding. A depression extending in the axial direction is made in the side of the blocking element facing the conductor, which depression forms a serpentine channel for a cooling fluid from an inlet port on the small radius to a discharge port on the highest radius, with the discharge port communicating with a ventilation bore of the rotor cap enclosing the rotor winding head. An improved cooling effect with a reduced flow of cooling fluid and an increase in the efficiency of the turbogenerator as a whole results.

Claims

1. A blocking element for the rotor head winding of a turbogenerator, the blocking element comprising: a three-dimensional shape which is matched to the contour of an adjacent subconductor of the rotor head winding, wherein the blocking element comprises, on its side facing the subconductor, a depression which extends in the axial direction and forms a channel for a cooling fluid from an inlet opening on the small radius to an outlet opening on the highest radius.

2. The blocking element as claimed in claim 1, wherein the subconductor is provided by a tangential conductor.

3. The blocking element as claimed in claim 1, wherein the subconductor is provided by an axial conductor.

4. The blocking element as claimed in claim 1, wherein the depression is of serpentine configuration.

5. The blocking element as claimed in claim 1, wherein the depression is of meandering configuration.

6. The blocking element as claimed in claim 1, wherein the outlet opening of the blocking element is aligned with a bore of a rotor cap surrounding the rotor head winding.

7. The blocking element as claimed in claim 1, wherein the blocking element is manufactured from glass.

8. The blocking element as claimed in claim 1, wherein the blocking element is manufactured from plastic.

9. The blocking element as claimed in claim 1, wherein the depression has a semi-elliptical shape in cross section.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The invention is explained in greater detail below by means of figures as an exemplary embodiment to an extent necessary for understanding. In this case:

[0018] FIG. 1 shows a blocking element 1 according to the invention having a meander-shaped cooling channel 2 on the side facing the tangential conductor, and

[0019] FIG. 2 shows a rotor cap with radial bores 5.

DETAILED DESCRIPTION OF INVENTION

[0020] The terms radial, tangential and axial relate to the alignment of the subconductors with respect to the axis of rotation of the rotor.

[0021] Blocking elements are inserted into the spaces between subconductors of a rotor winding head and mutually stabilize the subconductors. The subconductors can be provided by tangential conductors or axial conductors. A blocking element may almost completely fill the space spanned between two subconductors. The blocking elements are made of electrically insulating material, such as glass, plastic, synthetic material or ceramic.

[0022] In the embodiment according to FIG. 1, the blocking element has an approximately cuboidal shape and is provided on both sides with a meander-shaped cooling channel structure on the surfaces facing the winding/the subconductors, which hydraulically connects the region above the rotor shaft to the bore in the rotor cap. The cooling channel (the depression) may have a semi-elliptical shape in cross section.

[0023] The pumping action (or centrifugal forces), even without the element, conveys the cooling fluid, such as gas, air, hydrogen, radially outward. The additional element performs three tasks: 1) hydraulic connection of the areas of the spaces below the rotor cap (and below the rotor winding head) to the area above the rotor cap (through channels), 2) restricting the volume flow by increasing the resistance, 3) conducting the volume flow of the cooling fluid to the components to be cooled through cooling channels on the surface of the subconductor/element, said channels being semi-open.

[0024] It is easily apparent that significantly less volume flow occurs as a result of the blocking (e.g. only 6%). In comparison with a very common cooling mechanism (no blocking and no bores in the rotor cap), referred to as rotor pumping (also: thermo-siphon), there are marked improvements.

[0025] Despite the reduced volume flow, the blocking makes it possible to increase the heat transfer coefficient by more than 2.5 times. Without this invention, the heat transfer coefficient would be as much as 3 times as high, but then almost 20 times the volume flow would be required. This would then have the abovementioned disadvantages.

[0026] Possible manufacturing options include not only milling but also printing or other additive processes.

[0027] The present invention has been explained in detail for illustrative purposes on the basis of specific exemplary embodiments. Here, elements of the individual exemplary embodiments can also be combined with one another. Therefore, the invention should not be restricted to individual exemplary embodiments but should only be restricted by the appended claims.

REFERENCE SIGNS

[0028] 1—blocking element [0029] 2—depression, channel for cooling fluid [0030] 3—inlet on small radius [0031] 4—outlet on large radius [0032] 5—bore