In a system for effecting pressure control in a thermal power plant operated at low load connected fluidly in series, a relief conduit is disclosed herein. The relief conduit selectively transfers steam from a cold reheat conduit to the second extraction conduit. The plant further includes a boiler, a high-pressure turbine, an intermediate pressure turbine, a low pressure turbine, a main steam conduit for feeding steam from the boiler to an inlet of the high pressure turbine, a cold reheat conduit for feeding steam from an outlet of the high-pressure turbine through a reheat flow path in the boiler, and a first and second high pressure heaters. A first extraction conduit connects the cold reheat conduit to a first high pressure heater to transfer heat, and a second extraction conduit connects the intermediate pressure turbine to the second high pressure heater, to transfer heat.

A feedwater heater (10) for a steam generator communicating feedwater through an external heat exchanger (12), a deaerator (14) that allows the use of carbon steel feedwater tubes, a first heater (16), an evaporator section (18) and steam drum (17) for communicating a portion of the feedwater in the form of steam to the deaerator (14), and a second heater (20).

A steam turbine system including a steam turbine is provided, the steam turbine having an incoming and an outgoing steam side, and a turbine housing with a feed-through for a turbine shaft with a seal, whereby a fluid flow through the feed-through can be minimized, and a steam conducting system to the seal is present. The steam turbine includes a first sub-section a second sub-section, and a connecting line to a region of low pressure between two sub-sections. A steam supply through the steam conducting system is possible for starting up the steam turbine such that a steam flow from the outgoing steam side to the connecting line to the region of low pressure is possible, an incoming steam feed line has a shut-off that can be controlled such that a steam flow from the incoming steam side to the connecting line to the region of low pressure.

A steam turbine system including a steam turbine is provided, the steam turbine having an incoming and an outgoing steam side, and a turbine housing with a feed-through for a turbine shaft with a seal, whereby a fluid flow through the feed-through can be minimized, and a steam conducting system to the seal is present. The steam turbine includes a first sub-section a second sub-section, and a connecting line to a region of low pressure between two sub-sections. A steam supply through the steam conducting system is possible for starting up the steam turbine such that a steam flow from the outgoing steam side to the connecting line to the region of low pressure is possible, an incoming steam feed line has a shut-off that can be controlled such that a steam flow from the incoming steam side to the connecting line to the region of low pressure.