Two-shaft gas turbine

摘要

This invention suppresses the temperature rise of a wheel space between a high-pressure turbine (H) and a low-pressure turbine (L). A two-shaft gas turbine includes: a cooling air introduction path adapted to lead cooling air from the outside of a casing (17) to a wheel space via a low-pressure turbine initial stage stator blade (5) and via a diaphragm (11); an upstream side space seal portion (41) adapted to restrict and divide the upstream side space into an outer circumferential portion (25) and an inner circumferential portion (27) and to allow cooling air led from the cooling air introduction path to the upstream side space outer circumferential portion (27) to blow out into the upstream side space outer circumferential portion (25) to form a radially outward flow of air in the upstream side space outer circumferential portion (25); and a downstream side space seal portion (42) adapted to restrict and divide the downstream side space into an outer circumferential portion (26) and an inner circumferential portion (28) and to allow cooling air led from the cooling air introduction path to the downstream side space inner circumferential portion (28) to blow out into the downstream side space outer circumferential portion (26) to form a radially outward flow of air in the downstream side space outer circumferential portion (26).