Hitachi-ge Nuclear Energy, Ltd.

Hitachi, Ltd.

Naoyuki Ishida

Hisamichi Inoue

Masao Chaki

Akinori Tamura

Michio Murase

Kazuaki Kito

A heat exchanger has a tubular structure inside of which a medium flows. The heat exchanger includes a liquid film removal structure and a liquid film flowing-down assistance structure. The liquid film removal structure is joined to the tubular structure. The liquid film flowing-down assistance structure is coupled directly to the liquid film removal structure and is arranged between the tubular structure and an adjacent tubular structure and in parallel to the tubular structure.

Heat exchanger and heat transfer tube of the heat exchanger

A nozzle apparatus of a jet pump includes a nozzle base member, and a plurality of nozzles installed to the nozzle base member and forming a plurality of narrowing portions, in which a fluid passage cross-sectional area of a driving fluid passage formed in the nozzle is reduced.

Jet pump and reactor

A jet pump has a plurality of nozzles installed to a nozzle base, a throat and a diffuser. A first nozzle straight-tube portion, a first nozzle narrowing portion, a second nozzle straight-tube portion, a second nozzle narrowing portion, and a nozzle lower end portion formed in those nozzles are disposed in this order from the nozzle base to a ejection outlet. A narrowing angle of the second nozzle narrowing portion is larger than of the first nozzle narrowing portion. The jet pump forms, in a lower end portion of the throat, a flow passage narrowing portion having a flow passage cross-sectional area that gradually diminishes. This flow passage narrowing portion is inserted into an upper end portion of the diffuser.

Jet pump and nuclear reactor

A steam separator comprises an outer main swirler and an inner auxiliary swirler which is smaller than the main swirler. The swirlers are provided so as to be concentric on the inner wall at the lower side of the first stage inner cylinder. In the steam separator, when the gas-liquid two-phase flow which flows in the vicinity of the axial center of the first stage inner cylinder passes the auxiliary swirler, it is separated into steam and water by the centrifugal force. The separated water (droplets) is introduced into the main swirler. When the separated water (droplets) passes the main swirler, it is separated at the inner wall side of the first stage inner cylinder by the centrifugal force. Pressure loss in a steam separator is reduced and steam separation capability is increased without increasing the moisture from the steam separator.

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Hitachi, Japan

Naoyuki Ishida