A gas turbine plant including a gas turbine and a compressor is provided with a steam turbine plant including a steam turbine and a condenser, and, an exhaust heat recovery boiler. Steam from the exhaust heat recovery boiler is directly flown to the condenser of the steam turbine plant through a bypass control valve. A pressure sensor detects pressure in a turbine bypass system. A controller outputs, based on a set value from an input device and a process value from the pressure sensor, an open level instruction value to the control value so as to make the process value consistent with the set value in a predetermined sampling cycle. A corrector corrects the set value from the input device in a direction in which the open level instruction value decreases when the open level instruction value from the controller becomes a value that substantially fully opens the control valve.

A gas turbine plant including a gas turbine and a compressor is provided with a steam turbine plant including a steam turbine and a condenser, and, an exhaust heat recovery boiler. Steam from the exhaust heat recovery boiler is directly flown to the condenser of the steam turbine plant through a bypass control valve. A pressure sensor detects pressure in a turbine bypass system. A controller outputs, based on a set value from an input device and a process value from the pressure sensor, an open level instruction value to the control value so as to make the process value consistent with the set value in a predetermined sampling cycle. A corrector corrects the set value from the input device in a direction in which the open level instruction value decreases when the open level instruction value from the controller becomes a value that substantially fully opens the control valve.

A steam cycle for a power station, and to a method for operating, in particular for starting, a steam cycle. The steam cycle has a high-pressure turbine, a condenser and a steam generator. The steam generator is connected to the high-pressure turbine via a first line. Live steam quick-closing valves and live steam regulating valves for supplying the high-pressure turbine are arranged in the direction of the steam flow between the steam generator and the high-pressure turbine. A starting line is arranged downstream of the high-pressure turbine in the direction of the steam flow, the starting line connecting a waste steam region downstream of the high-pressure turbine with the condenser. At least one regulator regulates a closing of a starting valve for sealing the starting line, and an opening of the live steam valve, depending on the rotational speed, a temperature and load state of the high-pressure turbine.

A thermal energy recovery device capable of suppressing a rapid increase of thermal stress generated in an evaporator when the operation is started and a start-up method thereof are provided. The thermal energy recovery device includes an evaporator, a preheater, an energy recovery unit, a circulating flow path, a pump, a heating medium flow path for supplying a heating medium to the evaporator and the preheater, a flow adjustment unit provided in a portion on the upstream side than the evaporator within the heating medium flow path, and a control unit. The control unit controls the flow adjustment unit so that the inflow amount of the heating medium in a gas-phase to the evaporator gradually increases, in a state that the pump is stopped, until the temperature of the evaporator becomes a specified value.

A thermal energy recovery device capable of suppressing a rapid increase of thermal stress generated in an evaporator when the operation is started and a start-up method thereof are provided. The thermal energy recovery device includes an evaporator, a preheater, an energy recovery unit, a circulating flow path, a pump, a heating medium flow path for supplying a heating medium to the evaporator and the preheater, a flow adjustment unit provided in a portion on the upstream side than the evaporator within the heating medium flow path, and a control unit. The control unit controls the flow adjustment unit so that the inflow amount of the heating medium in a gas-phase to the evaporator gradually increases, in a state that the pump is stopped, until the temperature of the evaporator becomes a specified value.

Disclosed herein is a combined power generation system that includes a heat recovery steam generator configured to recover exhaust heat from a gas turbine to produce steam and including a high-pressure superheater and a reheater, a steam turbine operated by receiving the produced steam and including a high-pressure turbine, a medium-pressure turbine, and a low-pressure turbine, a condenser installed under the low-pressure turbine to condense steam, a high-pressure steam line for supplying the high-pressure turbine with the steam produced by the high-pressure superheater, a medium-pressure steam line for supplying the medium-pressure turbine with the steam that has passed through the high-pressure turbine, a high-pressure bypass line connected from the high-pressure steam line to the medium-pressure steam line, a reheat steam bypass line connected from downstream of the medium-pressure steam line to the condenser, and an additional high-pressure bypass line connected from the high-pressure steam line to the condenser.

Disclosed herein is a combined power generation system that includes a heat recovery steam generator configured to recover exhaust heat from a gas turbine to produce steam and including a high-pressure superheater and a reheater, a steam turbine operated by receiving the produced steam and including a high-pressure turbine, a medium-pressure turbine, and a low-pressure turbine, a condenser installed under the low-pressure turbine to condense steam, a high-pressure steam line for supplying the high-pressure turbine with the steam produced by the high-pressure superheater, a medium-pressure steam line for supplying the medium-pressure turbine with the steam that has passed through the high-pressure turbine, a high-pressure bypass line connected from the high-pressure steam line to the medium-pressure steam line, a reheat steam bypass line connected from downstream of the medium-pressure steam line to the condenser, and an additional high-pressure bypass line connected from the high-pressure steam line to the condenser.