DE102005036668B3 - Hydraulic machine for use as water or pump turbine has a labyrinth seal with an annular chambers, annular gap channels and connecting channels - Google Patents

Abstract

The invention relates to a water turbine or pump turbine or other hydraulic machine
- With a fixed and a rotating component;
- Between the components is a labyrinth seal, which is formed from the two components and through which a leakage current flows during operation;
- The labyrinth seal comprises a plurality of annular chambers and these conductive interconnecting annular gap-shaped channels.
The water turbine or pump turbine or other hydraulic machine according to the invention has the following features:
- The annular chambers have a rectangular or square cross-section;
- The annular gap-shaped channels are arranged such that the leakage flow is deflected both when entering a chamber and at the outlet from this by more than 90 °;
- The connecting channels, which are connected to one and the same chamber, are offset from each other.

Description

The invention relates to the field of hydraulic machines, in particular a water turbine or a pump turbine. It particularly relates to the field of labyrinth seals. As an example of such a hydraulic machine is on DE 198 08 877 A1 directed.

at such machines is running an impeller within a fixed housing, so that between the both create a gap. The gap must be sealed against leakage to minimize the leakage current as much as possible. For sealing Labyrinth seals are known. These come in a variety of embodiments. The simplest form is the so-called smooth labyrinth, in which the boundary walls of the light gap are free of jumps and more or less parallel next to each other. Another embodiment is the tiered labyrinth where the collaborating surfaces jagged are. Furthermore, numerous labyrinths are known that have a variety from small annular Have chambers, and annular gap-shaped channels, the chambers with each other connect.

Known such labyrinth seals go for example from the DE 1 554 223 A , of the DE 18 92 39 C as well as the US 59 24 844 A out.

you Strives to the leakage current through the sealing gap as far as possible to minimize, since it means power loss. At the same time the manufacturing cost to be as small as possible. In the known Labyrinth seals will not need these two features in the necessary Dimensions met.

Of the The invention is therefore based on the object, a labyrinth seal specify that for turbomachinery such as water turbines or the like is suitable, which is an extensive one Minimizing the leakage current and providing one more has minimal production costs.

These The object is achieved with a labyrinth seal according to claim 1.

Of the Inventor is based on a labyrinth seal, the a variety of annular Has chambers, further annular gap channels, the chambers with each other connect. An idea of the invention is that the annular chambers have a rectangular or square cross-section. hereby the production is facilitated. The areas concerned, off which a chamber is constructed, can be by piercing work out. The boundary surfaces of the chambers run thus parallel or perpendicular to each other.

The essential feature of the invention consists in the orientation of the chambers on the one hand, that is the location the boundary surfaces, and the connection channels between two adjacent chambers on the other. there become the channels according to the invention arranged that the leakage flow both when entering a chamber and deflected by more than 90 degrees when exiting a chamber becomes. The third characteristic feature is that the Inlet into a chamber and the outlet from a chamber against each other are offset so that the leakage current is not in a short circuit from the inlet to the outlet of the chamber directly, ie by the shortest route flows through. The flow path through the chamber after the deflection relative to the flow direction in the connecting channel be as big as possible.

The mentioned features have been found to be optimal in the sense of a hindrance the leakage flow and thus a minimization of the leakage current proven.

The Deflection of the leakage current when changing from a connection channel in a chamber as well as when changing from a chamber into a connecting channel could be very be great theoretically approximate, for example 180 degrees. This will be avoided, however, because there are sharp edges arise, which are particularly prone to erosion. Around To ensure a permanent configuration, the diversion becomes in the order of magnitude from 130 to 170 degrees. The flow direction in a connecting channel and the flow direction in the downstream chamber, for example, form an angle of 30 degrees with each other, which corresponds to a deflection of 150 degrees.

The Invention and the prior art are based on the drawing explained in more detail. In this is shown in detail as follows:

1 shows a Francis turbine in an axial section.

2 shows an enlarged schematic representation of a labyrinth seal according to the invention.

3 shows a configuration according to the invention of the chamber and inflow and outflow, again enlarged.

4 . 5 and 6 show conventional labyrinth seals.

In the 1 Francis turbine shown has an impeller as the main element 1 on, a housing 2 , a turbine cover 3 , a suction pipe 4 as well as an inlet spiral 5 ,

The impeller 1 has a wheel bottom 1.1 , an impeller wreath 1.2 and a plurality of impeller blades 1.3 on.

Decisive for the invention is a labyrinth seal 8th , This is formed from two annular components 8.1 and 8.2 , both of which are made of particularly corrosion and erosion resistant material. ring 8.1 is embedded in the circumference of the wheel rim and ring 8.2 in the opposite area of the housing 2 ,

Out 2 one recognizes the structure of the labyrinth seal according to the invention in detail. In the two rings 8.1 and 8.2 recesses are incorporated. The resulting boundary surfaces of the rings 8.1 and 8.2 form annular chambers with each other 9.1 . 9.2 and 9.3 and annular gap-shaped connecting channels 10.1 . 10.2 . 10.3 , The connection channels establish conductive connections between adjacent chambers.

The leakage current flowing from top to bottom is deflected by more than 90 degrees both when entering one of the chambers and at the outlet. In the present case, the deflection is about 120 degrees. The annular chambers 9.1 . 9.2 and 9.3 have a rectangular or square cross-section. The annular gap-shaped connecting channels are not connected at the very end of the respective rectangle, but at a certain distance thereof.

The situation is somewhat different in the embodiment according to FIG 3 , In this case, the leakage current that is in a connecting channel 10.1 introduced at entry into the following chamber 9.1 diverted by 150 degrees. Angle α between the two flow directions is thus 30 degrees. Entry into and exit from a chamber is at the end of the chamber.

The connection channels 10.1 . 10.2 . 10.3 will generally be parallel to each other. However, this could be different, so that two or more connecting channels form an angle with each other. The same applies to the chambers.

The cross sections of the annular chambers 9.1 . 9.2 and 9.3 will generally be rectangular, but they can also be square.

The said chamber connection channels are in accordance with the embodiment 2 from the two rings 8.1 . 8.2 formed by appropriate unscrewing or grooving with a turning steel.

The previously known embodiments are in the 4 to 6 shown. 4 shows a labyrinth with continuous surfaces. In this case, there is only one discontinuity, namely where the gap narrows.

In the embodiment according to 5 a rib labyrinth is provided, likewise in the embodiment according to FIG 6 ,

1

Wheel

1.1

wheel arch

1.2

rotor ring

1.3

impeller blades

2

casing

3

turbine cover

4

suction tube

5

enema spiral

6

diffuser

7

impeller shaft

8th

labyrinth seal

8.1

ring in the wheel rim

8.2

Ring in the case 2

9.1

chamber

9.2

chamber

9.3

chamber

10.1

connecting channel

10.2

connecting channel

10.3

connecting channel

Claims (3)

Hydro turbine or pump turbine or other hydraulic machine with a fixed ( 2 ) and a circulating ( 1 ) Component; between the components ( 1 . 2 ) there is a labyrinth seal ( 8th ) consisting of the two components ( 1 . 2 ) is formed and through which a leakage current flows during operation; the labyrinth seal ( 8th ) comprises a plurality of annular chambers ( 9.1 . 9.2 . 9.3 ) and these annularly interconnecting annular gap-shaped channels ( 10.1 . 10.2 . 10.3 ); the annular chambers ( 9.1 . 9.2 . 9.3 ) have a rectangular or square cross section; the annular gap-shaped channels ( 10.1 . 10.2 . 10.3 ) are arranged such that the leakage flow both in the entry into a chamber ( 9.1 . 9.2 . 9.3 ) as well as at the exit from this is deflected by more than 90 degrees; the connection channels ( 10.1 . 10.2 . 10.3 ) attached to one and the same chamber ( 9.1 . 9.2 . 9.3 ) connected are, are offset against each other. Water turbine or pump turbine or other hydraulic machine according to claim 1, characterized by such an arrangement of the chambers ( 9.1 . 9.2 . 9.3 ) and the connection channels ( 10.1 . 10.2 . 10.3 ) that the leakage current is deflected by 130 to 170 degrees when entering a chamber and exiting a chamber. Hydro turbine or pump turbine or other hydraulic machine according to claim 1 or 2, characterized in that the connecting channels ( 10.1 . 10.2 . 10.3 ) has a smaller flow area than the chambers ( 9.1 . 9.2 . 9.3 ) to have.