Abstract: In one embodiment, a plant control apparatus includes a first stop controller configured to, when stopping a plant, stop a steam turbine to start to drop rotating speed of a second shaft of the steam turbine from rated speed, and start to drop rotating speed of a first shaft of a gas turbine from the rated speed while continuing combustion of a combustor after the stop of the steam turbine. The apparatus further includes a second stop controller configured to shut off fuel of the combustor to stop the gas turbine when the rotating speed of the first shaft drops to first speed. The second stop controller stops the gas turbine such that the rotating speed of the first shaft catches up with the rotating speed of the second shaft at second speed that is equal to or lower than the first speed and a clutch is engaged.

Abstract: In one embodiment, a plant control apparatus controls a power plant. The plant includes a gas turbine, a generator driven by the gas turbine, an exhaust heat recovering boiler to generate first steam by using heat of exhaust gas from the gas turbine, a first steam turbine driven by the first steam, a reheater provided in the boiler and configured to heat exhaust steam from the first steam turbine by the exhaust gas to generate reheat steam, and a second steam turbine driven by the reheat steam. The apparatus includes a first warming-up module to supply second steam from equipment different from the boiler to the first steam turbine to warm up this turbine, before this turbine is started. The apparatus further includes a second warming-up module to supply the second steam to the reheater to warm up the reheater, before the first steam turbine is started.

Abstract: In one embodiment, a plant control apparatus includes a first stop controller configured to, when stopping a plant, stop a steam turbine to start to drop rotating speed of a second shaft of the steam turbine from rated speed, and start to drop rotating speed of a first shaft of a gas turbine from the rated speed while continuing combustion of a combustor after the stop of the steam turbine. The apparatus further includes a second stop controller configured to shut off fuel of the combustor to stop the gas turbine when the rotating speed of the first shaft drops to first speed. The second stop controller stops the gas turbine such that the rotating speed of the first shaft catches up with the rotating speed of the second shaft at second speed that is equal to or lower than the first speed and a clutch is engaged.

Abstract: In one embodiment, a plant control apparatus controls a power plant, which includes a gas turbine, a generator driven by the gas turbine, an exhaust heat recovering boiler to generate first steam using heat of exhaust gas from the gas turbine, a steam turbine driven by the first steam, and a clutch to connect a first shaft connected to the gas turbine and generator with a second shaft connected to the steam turbine. The apparatus includes a starting module to start the gas turbine and generator while holding the steam turbine in a stop state, when the clutch is in a released state. The apparatus further includes a warming module to warm the steam turbine by supplying second steam from equipment different from the boiler to the steam turbine in parallel with the starting of the gas turbine and generator, when the clutch is in a released state.

Abstract: In one embodiment, a plant control apparatus controls a power plant. The apparatus includes a gas turbine, an exhaust heat recovery boiler to generate main steam, a first steam turbine driven by first steam, and a first valve to supply the first steam to the first steam turbine. The plant further includes a reheater to generate reheat steam, a second steam turbine driven by second steam, and second and third valves to supply the second steam to the second steam turbine. The apparatus includes an acquisition module to acquire a setting value of total output of the first and second steam turbines, and a control module to adjust the total output to the setting value by controlling opening degrees of the first, second and third valves. The control module controls the second and third valves to different opening degrees when adjusting the total output to the setting value.

Abstract: A plant operation apparatus according to an embodiment operates a multi-shaft combined-cycle power plant including at least a plurality of gas turbines as a plurality of devices to be operated. The plant operation apparatus includes an interactive processing unit and a display unit. The interactive processing unit can display on the display unit an activation setting screen on which activation sequence in an activation operation of the gas turbines and number of gas turbines to be in an operating state after the activation operation can be selected, and/or a shutdown setting screen on which shutdown sequence in a shutdown operation of the gas turbines and number of gas turbines to be in an operating state after the shutdown operation can be selected.

Abstract: 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.

Abstract: In one embodiment, a plant control apparatus controls a power plant, which includes a gas turbine, a generator driven by the gas turbine, an exhaust heat recovering boiler to generate first steam using heat of exhaust gas from the gas turbine, a steam turbine driven by the first steam, and a clutch to connect a first shaft connected to the gas turbine and generator with a second shaft connected to the steam turbine. The apparatus includes a starting module to start the gas turbine and generator while holding the steam turbine in a stop state, when the clutch is in a released state. The apparatus further includes a warming module to warm the steam turbine by supplying second steam from equipment different from the boiler to the steam turbine in parallel with the starting of the gas turbine and generator, when the clutch is in a released state.

Abstract: In one embodiment, a plant control apparatus is configured to control a power generating plant that includes a gas turbine configured to be driven by a gas, an exhaust heat recovery boiler configured to generate steam by using heat of an exhaust gas from the gas turbine, a temperature reducing apparatus configured to cool, through a cooling medium, the steam generated by the exhaust heat recovery boiler, and a steam turbine configured to be driven by the steam cooled by the temperature reducing apparatus. The plant control apparatus includes an output controller configured to control output of the gas turbine, and a temperature reduction controller configured to control a cooling operation of the steam by the temperature reducing apparatus while the output controller controls the output of the gas turbine.

Abstract: In one embodiment, a plant control apparatus controls a power plant. The plant includes a gas turbine, a generator driven by the gas turbine, an exhaust heat recovering boiler to generate first steam by using heat of exhaust gas from the gas turbine, a first steam turbine driven by the first steam, a reheater provided in the boiler and configured to heat exhaust steam from the first steam turbine by the exhaust gas to generate reheat steam, and a second steam turbine driven by the reheat steam. The apparatus includes a first warming-up module to supply second steam from equipment different from the boiler to the first steam turbine to warm up this turbine, before this turbine is started. The apparatus further includes a second warming-up module to supply the second steam to the reheater to warm up the reheater, before the first steam turbine is started.

Abstract: In one embodiment, a combined cycle power plant includes first and second superheaters to generate first and second main steams, first and second reheaters to heat first and second discharge steams to generate first and second reheat steams, and a steam turbine to be supplied with the merged first and second reheat steams. The plant further includes a first valve to adjust a flow rate of the first discharge or reheat steam, and a second valve to adjust a flow rate of the second discharge or reheat steam. A plant control apparatus includes a determination module to determine a target opening degree of the second valve by using flow rates of the first and second main steams, and a controller to compare the determined target opening degree with a valve opening degree of the second valve and to control the second valve based on a comparison result.

Abstract: In one embodiment, a plant control apparatus controls a power plant including a combustor configured to burn fuel to generate a combustion gas, a gas turbine driven by the combustion gas from the combustor, a heat recovery steam generator configured to use heat of an exhaust gas from the gas turbine to generate steam, and a steam turbine driven by the steam from the heat recovery steam generator. The apparatus includes a gas turbine controller configured to control an output value of the gas turbine to a second output value that is larger than a first output value and depends on atmospheric temperature and then control the output value of the gas turbine to the first output value. The apparatus further includes a steam turbine controller configured to start up the steam turbine while the output value of the gas turbine is controlled to the first output value.

Abstract: In one embodiment, a plant includes a combustor to burn fuel with oxygen from an inlet guide vane (IGV) to generate a gas for a gas turbine (GT), and a heat recovery steam generator to use an exhaust gas from GT to generate steam for a steam turbine (ST). An apparatus controls an IGV opening degree to a first degree and a GT output value to a value larger than a first value between GT start and ST start. The first value is an output value at which exhaust gas temperature can be kept at a first temperature that depends on ST metal temperature, when the IGV opening degree is the first degree. The apparatus increases the IGV opening degree from the first degree based on steam temperature or the GT output value, while the GT output value is controlled to the value larger than the first value.

Abstract: 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.

Abstract: In one embodiment, a plant control apparatus is configured to control a power generating plant that includes a gas turbine configured to be driven by a gas, an exhaust heat recovery boiler configured to generate steam by using heat of an exhaust gas from the gas turbine, a temperature reducing apparatus configured to cool, through a cooling medium, the steam generated by the exhaust heat recovery boiler, and a steam turbine configured to be driven by the steam cooled by the temperature reducing apparatus. The plant control apparatus includes an output controller configured to control output of the gas turbine, and a temperature reduction controller configured to control a cooling operation of the steam by the temperature reducing apparatus while the output controller controls the output of the gas turbine.

Abstract: 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.

Abstract: A plant operation apparatus according to an embodiment operates a multi-shaft combined-cycle power plant including at least a plurality of gas turbines as a plurality of devices to be operated. The plant operation apparatus includes an interactive processing unit and a display unit. The interactive processing unit can display on the display unit an activation setting screen on which activation sequence in an activation operation of the gas turbines and number of gas turbines to be in an operating state after the activation operation can be selected, and/or a shutdown setting screen on which shutdown sequence in a shutdown operation of the gas turbines and number of gas turbines to be in an operating state after the shutdown operation can be selected.

Abstract: In one embodiment, a combined cycle power plant includes first and second superheaters to generate first and second main steams, first and second reheaters to heat first and second discharge steams to generate first and second reheat steams, and a steam turbine to be supplied with the merged first and second reheat steams. The plant further includes a first valve to adjust a flow rate of the first discharge or reheat steam, and a second valve to adjust a flow rate of the second discharge or reheat steam. A plant control apparatus includes a determination module to determine a target opening degree of the second valve by using flow rates of the first and second main steams, and a controller to compare the determined target opening degree with a valve opening degree of the second valve and to control the second valve based on a comparison result.

Abstract: According to one embodiment, a thermocouple abnormality detection system including: a plurality of thermocouples each including a plurality of thermocouple wires housed in a sheath; a transmission signal conversion unit configured to convert a thermo-electromotive force generated by each of the plurality of the thermocouple wires to a transmission signal and to output the transmission signal; a transmission unit configured to transmit the transmission signal outputted from the transmission signal conversion unit; and an abnormality detection circuit configured to detect an abnormality of each of the plurality of the thermocouples by comparing, with each other, the transmission signals obtained from the plurality of thermocouple wires provided in each of the thermocouples.

Abstract: In one embodiment, a plant control apparatus controls a combined cycle power generation plant. The plant includes a gas turbine, an exhaust heat recovery boiler including an evaporator to recover heat from an exhaust gas discharged from the gas turbine to generate steam and including a heat exchanger to exchange heat between the steam and an exhaust gas from the gas turbine and generate main steam, and a steam turbine driven by the main steam. The apparatus includes a control unit to increase output of the gas turbine to a target output after the gas turbine is paralleled with a generator. The target output is set so that an exhaust gas temperature of the gas turbine exceeds a maximum operating temperature of the exchanger and that a temperature of the exchanger becomes the maximum operating temperature or less by using a cooling effect given by the main steam.