Kabushiki Kaisha Toshiba

The Tokyo Electric Power Company, Incorporated

Tadashi Narabayashi

Mikihide Nakamaru

Hiroshi Miyano

Nobuhiko Tanaka

Katsumi Yamada

Shinichi Morooka

Hideaki Takahashi

Kenji Arai

Makoto Yasuda

Takehiko Saito

Michitsugu Mori

Hideaki Heki

Kouji Hiraiwa

Makoto Yasuoka

Osamu Ozaki

Tsuyoshi Shimoda

Seijiro Suzuki

Satoru Oomizu

Akira Nakamura

Akira Tanabe

Yutaka Asanuma

Kiyoshi Hattori

Michio Sato

Kenichi Tezuka

Hideaki Tezuka

Yasuhiko Aida

Katsuhiko Mawatari

Takao Fujii

Takashi Ishitori

Hideo Komita

Kunio Shimano

Kenji Kumagai

Shigeaki Tsunoyama

Shuichi Ohmori

Iwao Oshima

Miyuki Akiba

Takenori Ishiyama

Hiroshi Tonegawa

Akio Shioiri

Wataru Mizumachi

Disclosed is an ultrasonic Doppler flow measurment system that achieves flow measurement regardless of the temperature of a fluid. A temperature sensoris combined with a pipeto measure the temperature of a fluidA controllercalculates a frequency that will cause cavitation when an ultrasonic transducerexerts an ultrasonic vibration on the fluidon the basis of a temperature measured by the temperature sensorand controls a sinusoidal oscillator

Ultrasonic cavitating apparatus and ultrasonic doppler flow measurement system

The present invention is to provide a reactor core that allows a nuclear plant to continuously operate for a long term period, for example 15 years or longer, without requiring any fuel exchange, reduces the duration and number of maintenance steps involved in regular plant inspections, markedly improves plant availability and economic efficiency, and is effective in terms of nuclear nonproliferation. A plurality of fuel assemblies, themselves obtained by arranging fuel rodsand water rodsin square lattices, are arranged in a square lattice at a certain pitch. The bladesof a cross-shaped (cruciform) control rodin a cross section are inserted into four adjacent spaces formed by four fuel assembliesfacing each other. A value of 0.06 cmor greater is selected for the ratio (B/S) of the width (B) of each blade on the cruciform control rodand the surface (S) of the fuel lattice defined by the surface area of a square whose side is equal to the pitch between the fuel assemblies

Reactor core and method for operating nuclear reactor

The present invention provides a boiling water reactor nuclear power plant in which a reactor core support plate, upper grid plate, and a reactor core consisting of fuel assemblies supported by these plates are provided in the inner base portion of a nuclear reactor pressure vessel. Control rod guide tubes and a reactor core shroud are positioned over the upper grid plate, and a control rod drive mechanism is provided further above same, whereby the control rods can be inserted from above the reactor core, and natural circulation of cooling water inside the reactor can be achieved by means of a chimney effect of the control rod guide tubes. According to the above structure, there can be provided a compact and economical nuclear power plant.

Boiling water reactor nuclear power plant and its construction method

A jet finishing machine comprises: a water nozzle (1) for spouting a water jet flow of water in a liquid phase; a steam nozzle (3) for increasing the speed of a steam flow (4) in a gas phase to an ultrasonic speed to produce a steam jet flow (11) and for spouting the steam jet flow in excess of a thermal equilibrium with the water jet flow; and a mixing nozzle (2) for mixing the steam jet flow with the water jet flow so as to allow the steam jet flow to accelerate the water jet flow to form a two-phase jet flow (12) of the water jet flow and the steam jet flow and for directly spouting the two-phase jet flow onto a work piece (5).

Jet finishing machine, jet finishing system using two-phase jet

A feed water heating system for heating a feed water for a power-generating plant having a steam turbine, a condenser and a steam generator, comprises: a steam injector unit for receiving a plurality of bled steams having different pressures extracted from the steam turbine and an effluent water discharged from the condenser to mix the effluent water with the plurality of bled steams to raise the temperature and pressure of a mixture of the effluent water with the plurality of bled steams to deaerate and discharge the temperature and pressure raised mixture. The steam injector unit comprises: a multistage steam injector having a plurality of steam injectors connected in series for receiving one of the plurality of bled steams and a feed water to mix the one of the plurality of bled steams with the feed water to raise the temperature and pressure of a mixture of the one of the plurality of bled steams and the feed water to discharge the temperature and pressure raised mixture; a cylindrical container for housing therein the multistage steam injector; and a jet centrifugal deaerator, provided downstream of the multistage steam injector, for receiving a feed water discharged from the multistage steam injector and the bled steams to apply a centrifugal force to the feed water and the bled steams to deaerate the feed water to spatially separate a deaerated feed water from the bled steams to discharge the deaerated feed water.

Feed water heating system for power-generating plant

A separator/injector having an outlet pressure higher than an inlet pressure thereof is introduced instead of the dynamic equipment for a reactor recirculation system that is necessary in the prior art, to achieve both liquid-vapor separation and forced circulation. A jet pump and a recirculation flow-rate control valve are provided in a lower portion of a downcomer portion of a reactor pressure vessel. A shroud head has a double-walled structure, a two-phase liquid-vapor flow that is flowing from a lower portion of the lower shroud head is accelerated by an accelerator nozzle of the separator/injector, and a liquid component of the thus-separated flow is increased in pressure and guided into a jet pump through a space formed between the double shroud heads. Alternatively, a circular cylindrical separator/injector in which the steam nozzle and diffuser are disposed in a helical form in close proximity to the inner wall of a circular tube above the stand pipe could be provided instead of this separator/injector.

Steam separator, nuclear power generation plant, and boiler apparatus

A steam injector includes a casing having a water supply port and a steam intake port, the casing being generally composed of two halves fastened integrally, a water nozzle and a steam nozzle both disposed in the casing and communicated with the water supply port and the steam intake port, respectively, a steam-water mixing nozzle disposed on the downstream side in the casing and a diffuser disposed further downstream side in the casing. The steam injector further includes a guide member such as guide vane or spacer ring for guiding the steam to the steam-water mixing nozzle. The steam injector may includes a needle valve disposed in a steam jetting nozzle, disposed axially in the central portion of the casing, which is provided with a heat transfer preventing structure such as hollow wall structure provided on the outer peripheral surface of the steam jetting nozzle. The water nozzle may be composed of a wear resisting material and the wear resisting material may be provided on the surfaces of the steam jetting nozzle and the diffuser.

Steam injector

A boiling water reactor comprises a reactor pressure vessel accommodated in a vertical fashion, a core disposed at a low portion in the reactor pressure vessel, a plurality of control rods to be inserted from an upper side of the core into the spaces between adjacent fuel assemblies and withdrawn therefrom upwardly, a shroud surrounding the fuel assemblies so as to define the core and having an upper end opening, a shroud head which closes the upper end opening of the shroud and through which the control rods are inserted or withdrawn, a separator standing upward from the shroud head to carry out gas-water separation of steam generated from the core, a fixing pedestal disposed above the separator, a control rod driving mechanism mounted on the fixing pedestal and adapted to drive the control rods, a drier unit including a plurality of drier elements annularly arranged along an upper inner wall surface of the reactor pressure vessel and adapted to dry the steam passing through the steam flow hole of the fixing pedestal, and a jet pump unit disposed in a space between an outer surface of the shroud and an inner wall surface of the reactor pressure vessel.

Boiling water reactor

A steam injector includes a casing having water supply port and a steam intake port, the casing being generally composed of two halves fastened integrally, a water nozzle and a steam nozzle both disposed in the casing and communicated with the water supply port and the steam intake port, respectively, a steam-water mixing nozzle disposed on the downstream side in the casing and a diffuser disposed further downstream side in the casing. The steam injector further includes a guide member such as guide vane or spacer ring for guiding the steam to the steam-water mixing nozzle. The steam injector may includes a needle valve disposed in a steam jetting nozzle, disposed axially in the central portion of the casing, which is provided with a heat transfer preventing structure such as hollow wall structure provided on the outer peripheral surface of the steam jetting nozzle. The water nozzle may be composed of a wear resisting material and the wear resisting material may be provided on the surfaces of the steam jetting nozzle and the diffuser.

A steam injector system comprises a plurality of steam injectors each being provided with with a check valve adapted for water supply, a check valve adapted for steam supply, a check valve adapted for overflow and a check valve adapted for discharge and the respective water check valves, steam check valves, overflow check valves and discharge check valves are connected. In another aspect, a steam injector system comprises a plurality of first to last stage steam injectors arranged in series with each other, the last stage steam injector being provided with a relief valve disposed at a last stage overflow drain port, and a pressure pulsation absorbing device is disposed at least between the last stage overflow drain valve and the relief valve. A steam injector of an improved structure comprises an outer casing, a water nozzle disposed in the casing so as to extend axially therein, a central steam nozzle disposed inside the water nozzle coaxially therewith, a steam-water mixing nozzle disposed on a downstream side of the water nozzle and the central steam nozzle, and a peripheral steam nozzle mounted to the casing at a portion to supply steam from an outside into the steam-water mixing nozzle, wherein the steam is supplied so as to flow inside and outside the water.

Steam injector system

Growing community of inventors

Yokohama, Japan

Tadashi Narabayashi