Abstract: To improve the thermal efficiency when an exhaust heat recovery type combined cycle plant having a gas turbine and a steam turbine in combination is operated at a partial load, the gas turbine exhaust is recirculated and returned to the compressor, and the combustion temperature is prevented from being lowered at the partial load. Preferably, the temperature is maintained constant. In this way, the thermal efficiency during operation at partial load can be improved.

Abstract: To provide a combined-cycle power generation plant heat exchanged effectively in an exhaust heat, the recovery boiler is increased by suppressing on reducing the swirl present in the exhaust gas of a gas turbine. That is, a plurality of stationary blades 10 are arranged on the surface of a rear inner barrel in the circumferential direction of the rear inner barrel to partition an annular channel formed between a casing and the rear inner barrel. Thereby, it is possible to uniform the flow of exhaust gas with a low pressure drop.

Abstract: A gas turbine intake air cooling system and a method of operating the system are provided. The system can substantially reduce the construction cost for adding the system to a combined plant and improve the reliability of its chiller cooling system by indirectly dispersing exhaust heat from a chiller through an existing plant auxiliary equipment cooling system in the combined plant. The chiller cooling circuit is constructed so that the cooling water to the chiller is extracted through extraction water pipes branched from outlet pipes of heat exchangers composing the plant auxiliary equipment cooling system, and the cooling water heated by the chiller is returned to pipes downstream of the pumps through the returning pipes. In this construction, during operating of the chiller, a back-up division is operated to supply the plant auxiliary equipment cooling water to the chiller. By doing so, the gas turbine intake air system can be operated without affecting the combined plant side.

Abstract: An adjustable speed gas turbine power generation apparatus can maintain a rated output of the gas turbine generation apparatus irrespective of ambient temperature change. For this purpose, the rotational speed of the secondary winding of the generator is controlled by the gas turbine and alternating current excitation of the secondary winding is determined on the basis of the ambient temperature. The sucked air quantity (flow rate by weight) in the compressor can be increased by increasing the rotational speed of the gas turbine when the ambient temperature increases, so that an output from the gas turbine becomes nearly the rated output, while maintaining the desired frequency at the primary winding.

Abstract: The apparatus for cooling intake air includes a heat exchanger for transmitting the cold energy of fuel to a heat medium through an intermediate heat medium having a different property from the heat medium, a pressure controller for controlling the pressure within the heat exchanger so that a temperature of the intermediate heat medium is kept higher than a solidifying point of the heat medium, and an intake air cooling system for cooling intake air to be introduced into the gas turbine using the heat medium cold energy. The intermediate heat medium may be condensable by the cold energy of the fuel and vaporizable by the heat medium or may have a solidifying point lower than the fuel.

Abstract: In a method for determining a remaining lifetime of an aggregate constructed of a plurality of components and having at least one function, and an apparatus thereof, a first remaining lifetime of the aggregate is acquired based upon experimental aging degradation data on one characteristic of at least one component of the aggregate; a second remaining lifetime of the aggregate is acquired based upon experimental aging data with respect to at least one function of the aggregate; a third remaining lifetime of the aggregate is acquired based on both the experimental aging degradation data on the one characteristic of at least one component of the aggregate and the experimental aging data on at least one function of the aggregate; and, a remaining lifetime having the shortest lifetime from the first through third remaining lifetimes is output as the remaining lifetime of the aggregate.

Abstract: An electronic circuit is protected against radiation when the threshold voltage of a semiconductor element included in the electronic circuit is shifted, in a positive direction, to a predetermined upper limit on the basis of the formation of a trap level at an interface within the semiconductor element, the number of trapped positive charges in the semiconductor element is controlled so that the threshold voltage is shifted, in a negative direction, to a value less than the predetermined upper limit.

Abstract: Measurement values of conductivity of pH of water in the primary cooling water system of a boiling water atomic power plant are input through on-line and the measurement values of conductivity and pH at times of measurement when water quality changes are compared with values at the time of normal operation. Tendencies to increase or decrease the conductivity and pH are combined to prepare one diagnosis data, and causes of anomaly in progress in component apparatus members are discriminated and diagnosed by the diagnosis data. By using a correlation between logarithm of conductivity and pH in preparing the diagnosis data from combinations of conductivity and pH, causes of anomaly can be diagnosed more accurated.

Abstract: A direct cycle type atomic power plant provided with a means for suppressing transfer of radioactive nitrogen compounds generated by nuclear reaction in the core from the reactor water to steam, where an increase in the dose rate in the main steam system and the turbine system due to carry-over of radioactive nitrogen atom, .sup.16 N, generated in the core can be suppressed, and the radioactivity therein can be reduced.

Abstract: A water-cooled direct cycle nuclear plant including a nuclear reactor, a turbine, a condenser, a purifying means and a feed water heater successively arranged as main constitution, further comprises means for measuring iron concentration in cooling water, and means for injection iron into cooling water for controlling iron amount in cooling water at an optimum level. The iron amount to be injected into cooling water is calculated based on the measured iron concentration so as to make the iron accumulation rate on fuel rod to be not less than 0.5 mg/m.sup.2 /hr.

Abstract: A nuclear reactor start-up method of starting up a boiling water reactor which is in the cold shut-down state. The method includessetting a subcooled temperature of a coolant in a reactor core inlet to a range smaller than a critical subcooled temperature which is determined by the condition whereby the coolant starts boiling in the reactor core and the condition whereby the instability due to a periodic variation of buoyancy begins,thereafter starting an increase of power of the reactor.

Abstract: A nuclear reactor is equipped with a cooling water circulation system which includes a water-feed conduit and a drain conduit to circulate the cooling water to and from a pressure vessel which surrounds a reactor core, the cooling water having a free liquid level maintained above the reactor core. The drain conduit is inserted in the pressure vessel from the upper side toward the lower side relative to the free liquid level. A double tube consisting of an inner tube and an outer tube maintaining a gap therebetween is formed in the end portion of the drain conduit. The inner tube and outer tube being continuous with the drain conduit, the opening at the lower end of the inner tube is located below said free liquid level but above the reactor core. The opening at the upper end of the outer tube is located above the free liquid level. The opening at the lower end of said outer tube is located below the reactor core.

Abstract: After a nuclear reactor is shut down, the top of a nuclear fuel assembly in the core of a reactor pressure vessel is covered with a cap through which an air supply line, a warm water supply line and a sampling line extend. Air is supplied through the air supply line to form an air layer in the cap to stop the passage of a current of cooling water through the fuel assembly. A portion of the cooling water in the reactor pressure vessel is pumped up and heated to prepare warm water which is supplied through the warm water supply line to the fuel assembly so as to replace the cooling water in the fuel assembly by the warm water. After the fuel assembly is filled with the warm water, the fuel assembly is allowed to stand as it is for a predetermined period of time, and then a portion of the warm water in the fuel assembly is sampled. The radioactivity of the sample of the warm water is measured thereby to detect whether any of the nuclear fuel elements constituting the fuel assembly under test is a faulty element.