Abstract: A steam turbine pipe 1 of an embodiment includes: an upper half side main steam pipe 11 that leads steam to a steam turbine; an upper half side main steam control valve 30 that intervenes in the upper half side main steam pipe 11; and a post-valve drain pipe 31 that is connected to the upper half side main steam control valve 30 and leads drain to an outside. The steam turbine pipe 1 further includes: a shut-off valve 32 that intervenes in the post-valve drain pipe 31; and a branching pipe 60 that makes the post-valve drain pipe 31 on the side closer to the upper half side main steam control valve 30 than is the shut-off valve 32 communicate with the upper half side main steam pipe 11 between the upper half side main steam control valve 30 and a high-pressure turbine 200.

Abstract: A steam turbine pipe 1 of an embodiment includes: an upper half side main steam pipe 11 that leads steam to a steam turbine; an upper half side main steam control valve 30 that intervenes in the upper half side main steam pipe 11; and a post-valve drain pipe 31 that is connected to the upper half side main steam control valve 30 and leads drain to an outside. The steam turbine pipe 1 further includes: a shut-off valve 32 that intervenes in the post-valve drain pipe 31; and a branching pipe 60 that makes the post-valve drain pipe 31 on the side closer to the upper half side main steam control valve 30 than is the shut-off valve 32 communicate with the upper half side main steam pipe 11 between the upper half side main steam control valve 30 and a high-pressure turbine 200.

Abstract: A steam turbine pipe 1 of an embodiment includes: an upper half side main steam pipe 11 that leads steam to a steam turbine; an upper half side main steam control valve 30 that intervenes in the upper half side main steam pipe 11; and a post-valve drain pipe 31 that is connected to the upper half side main steam control valve 30 and leads drain to an outside. The steam turbine pipe 1 further includes: a shut-off valve 32 that intervenes in the post-valve drain pipe 31; and a branching pipe 60 that makes the post-valve drain pipe 31 on the side closer to the upper half side main steam control valve 30 than is the shut-off valve 32 communicate with the upper half side main steam pipe 11 between the upper half side main steam control valve 30 and a high-pressure turbine 200.

Abstract: A steam turbine pipe 1 of an embodiment includes: an upper half side main steam pipe 11 that leads steam to a steam turbine; an upper half side main steam control valve 30 that intervenes in the upper half side main steam pipe 11; and a post-valve drain pipe 31 that is connected to the upper half side main steam control valve 30 and leads drain to an outside. The steam turbine pipe 1 further includes: a shut-off valve 32 that intervenes in the post-valve drain pipe 31; and a branching pipe 60 that makes the post-valve drain pipe 31 on the side closer to the upper half side main steam control valve 30 than is the shut-off valve 32 communicate with the upper half side main steam pipe 11 between the upper half side main steam control valve 30 and a high-pressure turbine 200.

Abstract: A start-up method of a steam turbine plant includes a first step and a second step. The first step is performed at an aeration start time. In the first step, a reheat steam pressure of an aeration boiler is set to be a reheat steam pressure required by a steam turbine or less. Besides, a reheat steam pressure of a standby boiler is set to be a reheat steam pressure required for the standby boiler or more. The second step is performed when a load of the steam turbine becomes a predetermined value. In the second step, the reheat steam pressure of the aeration boiler is increased to the same degree as the reheat steam pressure of the standby boiler. After that, steam from the aeration boiler and steam from the standby boiler are merged to be supplied to the steam turbine.

Abstract: A start-up method of a steam turbine plant includes a first step and a second step. The first step is performed at an aeration start time. In the first step, a reheat steam pressure of an aeration boiler is set to be a reheat steam pressure required by a steam turbine or less. Besides, a reheat steam pressure of a standby boiler is set to be a reheat steam pressure required for the standby boiler or more. The second step is performed when a load of the steam turbine becomes a predetermined value. In the second step, the reheat steam pressure of the aeration boiler is increased to the same degree as the reheat steam pressure of the standby boiler. After that, steam from the aeration boiler and steam from the standby boiler are merged to be supplied to the steam turbine.

Abstract: A steam turbine pipe 1 of an embodiment includes: an upper half side main steam pipe 11 that leads steam to a steam turbine; an upper half side main steam control valve 30 that intervenes in the upper half side main steam pipe 11; and a post-valve drain pipe 31 that is connected to the upper half side main steam control valve 30 and leads drain to an outside. The steam turbine pipe 1 further includes: a shut-off valve 32 that intervenes in the post-valve drain pipe 31; and a branching pipe 60 that makes the post-valve drain pipe 31 on the side closer to the upper half side main steam control valve 30 than is the shut-off valve 32 communicate with the upper half side main steam pipe 11 between the upper half side main steam control valve 30 and a high-pressure turbine 200.