Abstract: A centrifugal compressor is equipped with an impeller having a blade angle distribution that makes it possible to achieve a relatively wide operating range. The blade angle of a shroud side facing a circular plate of a blade is termed a first angle and a blade angle of a hub side disposed at the circular plate is a second angle. The shroud side is formed in a curved shape having an angle distribution from a front area in a shaft direction toward a centrifugal direction in which the first angle is the local maximum point before a substantially middle portion and the local minimum point after the substantially middle point. The hub side is formed in a curved shape having an angle distribution from the front area in the shaft direction toward the centrifugal direction in which the second angle is the maximum local point before the substantially middle portion.

Abstract: A multistage centrifugal compressor includes a rotary shaft, and multistage impellers attached to the rotary shaft. Each of the impellers includes a hub, a shroud and blades therebetween in a radial cascade arrangement. An annular suction passage for guiding the fluid flow from the inward radial direction to a blade inlet is disposed upstream of the centrifugal impeller. A diffuser is disposed downstream of the centrifugal impeller. A bend portion is disposed downstream of the diffuser, and a return channel with a guide blade portion is disposed downstream of the bend portion. The annular suction passage at a hub side includes an axial parallel portion.

Abstract: A turbine nozzle (2) that, among components constructing a turbine, reaches particularly high temperature is efficiently cooled with a relatively simple structure. A double casing structure in which a turbine casing (7) is provided outside a turbine shell (5) is formed. The turbine casing (7) functions as a flow path (24) for compressed air (20?21) before combustion. The turbine shell (5) covers a turbine nozzle (2) and a radial turbine impeller (3) and forms flow paths (15, 16) for combustion gas (10?11?12?13). The compressed air (21) before combustion flowing in the flow path (24), for compressed air, having air-tightness between itself and the outside air is blown to the turbine nozzle (2) through a through-hole (51) penetrating both wall surfaces of the turbine shell (5). By this, the turbine nozzle (2) is cooled and the compressed air used to cool the turbine nozzle is made to flow toward the turbine impeller (3).

Abstract: An object of the present invention is to provide a gas turbine power generator capable of increasing the power generation efficiency in partial load operation and decreasing a variation in the number of rotations caused by a variation in power generation load. The gas turbine power generator comprises a compressor (2) for compressing air, a combustor (5) for burning the compressed air and fuel, a turbine (6) driven by combustion gas produced in the combustor and driving the compressor (2) and a generator (7), a regenerative heat exchanger (4) for exchanging heat between exhaust gas from the turbine and the compressed air led into the combustor, an intake air sprayer (1), and a humidifier (3). Intake air flown into the regenerative heat exchanger (4) is humidified and cooled by the intake air sprayer (1) and the humidifier (3).

Abstract: Provided is a gas turbine power plant in which a rotor of a generator is journalled by water lubrication bearings into which a part of cooling water for cooling the generator is fed. Since the lubrication water has a viscosity lower than that of lubrication oil, it is possible to provide a gas turbine power plant with less energy loss resulting in lower power consumption for accessories, and in high power generation efficiency.

Abstract: An object of the present invention is to provide a gas turbine power generator capable of increasing the power generation efficiency in partial load operation and decreasing a variation in the number of rotations caused by a variation in power generation load. The gas turbine power generator comprises a compressor (2) for compressing air, a combustor (5) for burning the compressed air and fuel, a turbine (6) driven by combustion gas produced in the combustor and driving the compressor (2) and a generator (7), a regenerative heat exchanger (4) for exchanging heat between exhaust gas from the turbine and the compressed air led into the combustor, an intake air sprayer (1), and a humidifier (3). Intake air flown into the regenerative heat exchanger (4) is humidified and cooled by the intake air sprayer (1) and the humidifier (3).

Abstract: A video receiver includes a tuner, a QAM demodulator including a selective gated PLL carrier recovery circuit, and a digital equalizer. The selective gated PLL carrier recovery circuit has a normal operation mode and a selection control mode. The channel changing of the tuner is performed after the selective gated PLL carrier recovery circuit is set to the selection control mode and the digital equalizer is held at its current state.

Abstract: A digital signal transmission system adopting a quadrature amplitude modulation and demodulation principle and feasible for large capacity data transmission in which a number of levels are used. Each of a modulating and a demodulating device of the system is constructed to shift the phase difference between two carrier waves by a suitable angle of .DELTA..theta. radian from .pi./2 radian. The tuning phase in the demodulating device is limited to one so as to allow a bit error rate characteristic to remain constant.

Abstract: In a demodulation system comprising a demodulator (22) which demodulates a quadrature amplitude modulated signal into first and second sets of output digital signals by the use of a reference carrier signal (CA), a specific phase control signal is produced in a transient state by discriminating a plurality of areas and a plurality of zones defined on a phase plane of the modulated signal. The areas are defined by dividing the phase plane by both a pair of quadrant reference axes and a pair of auxiliary reference axes phase shifted by .pi./4 (radians) relative to the quadrant decision axes. The zones are defined along and adjacent to the auxiliary reference axes. First and second detection signals (S.sub.1 and S.sub.2) are produced by a read-only memory (35) as results of discrimination of the areas and the zones, respectively. The specific phase control signal is switched to a normal phase control signal produced in a normal state in the known manner.

Abstract: In a demodulation circuit, a timing synchronizing circuit generates a timing signal representing a sampling timing of an A/D converter and has a timing signal generator, a polarity identification circuit and a logic circuit. The timing signal generator is phase-controlled by a phase control signal and generates a timing signal. The polarity identification circuit identifies a polarity of a differential coefficient of the baseband signal at a sampling point of the A/D converter and generates a polarity identification signal. Upon logic processing, the logic circuit supplies to the timing signal generator the phase control signal representing a deviation of an actual sampling point of the baseband signal from an optimal sampling point. A carrier asynchronism detection circuit detects an asynchronism state of a carrier regenerating circuit and supplies to the timing synchronizing circuit a signal which changes its loop parameter.