Combustor having an additional cooling component for liner and gas turbine including such combustor
A combustor includes a liner configured to define a combustion chamber and extending in a longitudinal direction, a transition piece configured to overlap an end of the liner while being spaced apart from the end of the liner at a predetermined spacing distance, the transition piece extending in the longitudinal direction of the liner, and a shroud disposed between the liner and the transition piece and coupled to the liner, in which the liner and an inner surface of the shroud define a cooling flow path, and in which the cooling flow path is formed with a turbulator to allow the air, which flows in the cooling flow path, to flow as a turbulent flow in order to dissipate heat from the liner.
1 . A combustor comprising:
a liner configured to define a combustion chamber and extending in a longitudinal direction;
a transition piece configured to overlap an end of the liner while being spaced apart from the end of the liner at a predetermined spacing distance, the transition piece extending in the longitudinal direction of the liner; and
a shroud disposed between the liner and the transition piece and coupled to the liner,
wherein the liner and an inner surface of the shroud define a cooling flow path, and
wherein the cooling flow path is formed with a turbulator to allow a cooling air, which flows in the cooling flow path, to flow as a turbulent flow in order to dissipate heat from the liner,
wherein, when a radial direction is defined as a direction extending from a center of the combustion chamber toward a circumferential periphery of the liner,
the shroud includes a narrowing stepped portion formed on the inner surface of the shroud,
the narrowing stepped portion being configured such that a radial distance between the liner and the inner surface of the shroud decreases from an upstream side to a downstream side along a flow direction of the cooling air flowing through the cooling flow path.
2 . The combustor of claim 1 , wherein
the turbulator protrudes from the liner toward the cooling flow path.
3 . The combustor of claim 2 , wherein the turbulator is included in the liner, and the liner comprises a flow path forming portion configured to define the cooling flow path, and the turbulator protrudes from the flow path forming portion.
4 . The combustor of claim 2 , wherein the turbulator is formed to protrude perpendicularly to a longitudinal direction of the cooling flow path.
5 . The combustor of claim 2 , wherein the turbulator is provided as a plurality of turbulators arranged at predetermined intervals in a longitudinal direction of the cooling flow path.
6 . The combustor of claim 5 , wherein, when a length by which each of the plurality of turbulators protrudes is defined as e, and an interval between the plurality of turbulators is defined as p, a ratio of e to p is 8 or more and 10 or less.
7 . The combustor of claim 1 , wherein the shroud comprises a swirler in an inlet flow path to form a swirl in the inlet flow path, which communicates with an inlet of the cooling flow path.
8 . The combustor of claim 7 , wherein an inner surface of the swirler defines the inlet flow path, and the inlet flow path has an extension direction inclined with respect to a longitudinal direction of the cooling flow path.
9 . The combustor of claim 7 , wherein the inlet flow path has an extension direction that is a direction made by combining two directions perpendicular to a longitudinal direction of the cooling flow path.
10 . The combustor of claim 7 , wherein a distance between two farthest points on a cross-sectional area of the swirler is equal to or larger than a height of the cooling flow path.
11 . The combustor of claim 1 , wherein an outlet flow path of the cooling flow path extends in a longitudinal direction of the cooling flow path.
12 . The combustor of claim 1 , wherein at least a part of the cooling flow path has a section in which a cross-sectional area decreases from the upstream side to the downstream side.
13 . The combustor of claim 12 , wherein the section in which the cross-sectional area of the cooling flow path decreases is provided where the narrowing stepped portion is formed.
14 . The combustor of claim 12 ,
wherein the turbulator protrudes from the liner toward the cooling flow path,
wherein the section in which the cross-sectional area of the cooling flow path decreases corresponds to a section in which the turbulator is formed.
15 . The combustor of claim 1 , further comprising:
a strut disposed at a rear side of the liner and between the shroud and the liner and configured to support the shroud and the liner.
16 . The combustor of claim 1 ,
wherein the turbulator is provided as a plurality of turbulators along the flow direction of the cooling air, which protrude from the liner toward the cooling flow path, and
wherein the narrowing stepped portion is provided as a plurality of narrowing stepped portions along the flow direction of the cooling air,
wherein, when the longitudinal direction is defined as the direction from the upstream side to the downstream along the flow direction of the cooling air flowing, a longitudinal position of each of the plurality of narrowing stepped portions corresponds to a longitudinal position of one of the plurality of turbulators.
17 . The combustor of claim 1 ,
wherein the narrowing stepped portion is provided as a plurality of narrowing stepped portions arranged along the flow direction of the cooling air through the cooling flow path,
wherein the shroud further includes a single entry stepped portion formed on the inner surface of the shroud, the single entry stepped portion being disposed upstream of all of the plurality of narrowing stepped portions with respect to the flow direction of the cooling air such that the single entry stepped portion being closer to an inlet of the cooling flow path than said all of the plurality of narrowing stepped portions, and
wherein the single entry stepped portion is configured such that the radial distance between the liner and the inner surface of the shroud increases from the upstream side to the downstream side along the flow direction of the cooling air flowing through the cooling flow path.
18 . A gas turbine comprising:
a compressor;
a turbine configured to produce electric power by using air compressed by the compressor; and
a combustor configured to combust the air compressed by the compressor,
wherein the combustor comprises:
a liner configured to define a combustion chamber and extending in a longitudinal direction;
a transition piece configured to overlap an end of the liner while being spaced apart from the end of the liner at a predetermined spacing distance, the transition piece extending in the longitudinal direction of the liner; and
a shroud disposed between the liner and the transition piece and coupled to the liner,
wherein the liner and an inner surface of the shroud define a cooling flow path, and
wherein the cooling flow path is formed with a turbulator to allow a cooling air, which flows in the cooling flow path, to flow as a turbulent flow in order to dissipate heat from the liner,
wherein, when a radial direction is defined as a direction extending from a center of the combustion chamber toward a circumferential periphery of the liner,
the shroud includes a narrowing stepped portion formed on the inner surface of the shroud,
the narrowing stepped portion being configured such that a radial distance between the liner and the inner surface of the shroud decreases from an upstream side to a downstream side along a flow direction of the cooling air flowing through the cooling flow path.