Sealing clearance control in turbomachines
The turbomachine comprises a stationary component, a rotary component, rotatingly supported in the stationary component, and a sealing arrangement between the rotary component and the stationary component. A cooling arrangement is further provided, which is configured and designed for delivering a cooling fluid to the sealing arrangement and removing heat therefrom.
1. A turbomachine, comprising:
a stationary component;
a rotary component, rotatingly supported in the stationary component;
an annular seal disposed between the rotary component and the stationary component, the annular seal having a sealing surface facing the rotary component; and
a cooling chamber arranged in thermal communication with the annular seal, the cooling chamber having a wall disposed between the cooling chamber and the sealing surface of the annular seal, the cooling chamber arranged to circulate a cooling fluid through the cooling chamber to remove heat from the annular seal to vary the thermal expansion of the annular seal.
2. The turbomachine of claim 1 , wherein the annular seal comprises at least a portion of the cooling chamber.
3. The turbomachine of claim 2 , wherein the stationary component further comprises at least one cooling fluid-delivery duct, which is fluidly connected with the cooling chamber, for delivering cooling fluid therein.
4. The turbomachine of claim 3 , wherein the stationary component further comprises at least one cooling fluid-discharge duct in fluid communication with the cooling chamber, for removing cooling fluid therefrom.
5. The turbomachine of claim 2 , wherein the stationary component includes a seat to mount the annular seal thereto.
6. The turbomachine of claim 5 , wherein the annular seal and the seat are capable of mutual radial displacements.
7. The turbomachine of claim 5 , wherein the cooling chamber is arranged annularly between the annular seal and the seat such that the annular seal and the stationary component form the cooling chamber.
8. The turbomachine of claim 5 , wherein the cooling chamber is formed in the annular seal.
9. The turbomachine of claim 8 , wherein the annular seal is hollow to form the cooling chamber.
10. The turbomachine of claim 9 , wherein the cooling chamber is substantially tubular.
11. The turbomachine of claim 9 , wherein the cooling chamber further includes partition walls therein to form a labyrinth.
12. The turbomachine of claim 11 , wherein the cooling chamber includes at least one cooling-fluid inlet and at least one cooling-fluid outlet.
13. The turbomachine of claim 12 , wherein the stationary component further comprises:
at least one cooling fluid-delivery duct in fluid communication with the at least one cooling-fluid inlet of the cooling chamber; and
at least one cooling fluid-discharge duct in fluid communication with the cooling chamber, for removing cooling fluid therefrom.
14. The turbomachine of claim 5 , wherein sealing gaskets are located between the annular seal and the seat of the stationary component.
15. The turbomachine of claim 1 , wherein the rotary component comprises an impeller.
16. The turbomachine of claim 15 , wherein the impeller comprises an impeller disc, an impeller shroud, an impeller eye and a plurality of blades arranged between the impeller disc and the impeller shroud, forming a plurality of impeller vanes; and wherein the annular seal is located around the impeller eye for sealing the impeller eye against the stationary component.
17. The turbomachine of claim 15 , wherein the rotary component comprises a balancing drum and wherein the annular seal is located around the balancing drum for sealing the balancing drum against the stationary component.
18. A method for controlling a seal clearance in a turbomachine between a rotary component of the turbomachine and an annular seal co-acting with the rotary component, the method comprising:
circulating selectively a cooling fluid through a cooling chamber in thermal communication with the annular seal to remove heat from the annular seal for controlling thermal expansion of the annular seal during operation of the turbomachine.
19. The method of claim 18 , further includes:
delivering a cooling fluid in the cooling chamber through at least one cooling fluid-delivery duct; and
removing the cooling fluid from the cooling chamber through at least one cooling fluid-discharge duct.
20. The method of claim 18 , further comprising sealing the cooling chamber against a volume where the rotary component is housed.