Impingement cooled structure

An impingement cooled structure comprising:

• (a) a plurality of shroud members disposed in a circumferential direction to constitute a ring-shaped shroud surrounding a hot gas stream;
• and
• (b) a shroud cover mounted on radial outside faces of the plurality of shroud members to form a cavity therebetween,
• wherein the shroud cover has a first impingement cooling hole formed therein that communicates with the cavity and allows cooling air to be jetted toward a bottom surface of the cavity so as to cool the bottom surface of the cavity by impingement,
• wherein each shroud member of the plurality of shroud members has a hole fin, wherein the hole fin extends in a radial outward direction from the bottom surface of the cavity toward an inner surface of the shroud cover, and the hole fin divides the cavity in the hot gas stream into a first plurality of sub-cavities, and the hole fin has a second impingement cooling hole formed obliquely relative to a bottom surface of a first sub-cavity so that the second impingement cooling hole allows the cooling air having flowed through the first impingement cooling hole to be jetted obliquely toward the bottom surface of the first sub-cavity adjacent thereto,
• wherein each shroud member of the plurality of shroud members comprises
• i. an inner surface extending along the hot gas stream to be directly exposed to the hot gas stream;
• ii. an outer surface positioned at an outside of the inner surface to constitute a portion of the bottom surface of the cavity;
• iii. an upstream flange extending in a radial outward direction from an upstream side of the hot gas stream so as to be fixed to a fixing portion;
• and
• iv. a downstream flange extending in a radial outward direction from a downstream side of the hot gas stream so as to be fixed to the fixing portion,
• wherein the upstream flange and the downstream flange are disposed to provide a cooling air chamber outside the shroud cover,
• wherein the hole fin extends in the radial outward direction towards the inner surface of the shroud cover from the outer surface constituting the bottom surface of the cavity in order to divide the cavity into the first plurality of sub-cavities adjacent to each other along the hot gas stream, and
• wherein a gap is formed between a radial outward end of the hole fin and the inner surface of the shroud cover, wherein a height Δh of the gap is 0.2 or less times as high as a height h of the hole fin.

An impingement cooled structure comprising:

• (a) a plurality of shroud members disposed in a circumferential direction to constitute a ring-shaped shroud surrounding a hot gas stream;
• and
• (b) a shroud cover mounted on radial outside faces of the plurality of shroud members to form a cavity therebetween,
• wherein the shroud cover has a first impingement cooling hole formed therein that communicates with the cavity and allows cooling air to be jetted toward a bottom surface of the cavity so as to cool the bottom surface of the cavity by impingement,
• wherein each shroud member of the plurality of shroud members has a hole fin, wherein the hole fin extends in a radial outward direction from the bottom surface of the cavity toward an inner surface of the shroud cover, and the hole fin divides the cavity in the hot gas stream into a first plurality of sub-cavities, and the hole fin has a second impingement cooling hole formed obliquely relative to a bottom surface of a first sub-cavity so that the second impingement cooling hole allows the cooling air having flowed through the first impingement cooling hole to be jetted obliquely toward the bottom surface of the first sub-cavity adjacent thereto,
• wherein each shroud member of the plurality of shroud members comprises
• i. an inner surface extending along the hot gas stream to be directly exposed to the hot gas stream;
• ii. an outer surface positioned at an outside of the inner surface to constitute a portion of the bottom surface of the cavity;
• iii. an upstream flange extending in a radial outward direction from an upstream side of the hot gas stream so as to be fixed to a fixing portion;
• and
• iv. a downstream flange extending in a radial outward direction from a downstream side of the hot gas stream so as to be fixed to the fixing portion,
• wherein the upstream flange and the downstream flange are disposed to provide a cooling air chamber outside the shroud cover,
• wherein the hole fin extends in the radial outward direction towards the inner surface of the shroud cover from the outer surface constituting the bottom surface of the cavity in order to divide the cavity into the first plurality of sub-cavities adjacent to each other along the hot gas stream, and
• wherein an angle of the second impingement cooling hole to a bottom surface of the first sub-cavity is 45° or less, and an impingement height e is 0.26 or less times as long as a length L of the first sub-cavity in a flow path direction.