Hitachi, Ltd.

Taisei Uede

Takahiro Daikoku

Wataru Nakayama

Masahiro Ikegawa

Norihide Saho

Takeo Nemoto

Hisanao Ogata

Yasuo Yamashita

Hisashi Isogami

Hiroyuki Kawakami

Yoichi Ono

A plurality of cryopumps are installed in each of a plurality of neutral beam injection apparatuses disposed around a nuclear fusion apparatus. The cryopanels of each of the cryopumps are refrigerated by a small helium refrigerating machine. Since the cryopanels are refrigerated from room temperature with cold liquid nitrogen used for refrigerating a heat shield plate, then a small helium refrigerating machine and finally cold liquid helium itself, various valves and a small helium refrigerating machine are disposed. This permits refrigeration of a plurality of cryopumps within a short time, thereby saving the power consumption and improving the operating reliability of a refrigeration system.

Cryogenic refrigeration system and refrigeration method therefor

A vacuum vessel has a member to be cooled to a low operating temperature inside the vacuum vessel and a main cooling circuit having fluid for cooling the member to operating temperature. The main cooling circuit has first fluid refrigerating means located at the vacuum vessel. To achieve rapid cooling, there is a pre-cooling circuit having the fluid for pre-cooling the member towards the operating temperature. The pre-cooling circuit has second fluid refrigerating means operating independently of the first fluid refrigerating means. The pre-cooling circuit cools the main cooling circuit, prior to operation of the main cooling circuit, by passage of the fluid from the pre-cooling circuit into the main cooling circuit. A heat shield cooling circuit for cooling a heat shield cools the second fluid refrigerating means of the pre-cooling circuit.

Vacuum vessel having a cooled member

A cryopump for effecting a cooling operation by a freezing medium such as liquid helium. A plurality of radiation-heat shield plates for protecting cryopanels against an external heat radiation are provided in opposed relation to a gas inlet of the cryopump. Particularly, a plurality of groups of such radiation-heat shield plates are provided in such a manner that the radiation-heat shield plates of each group are arranged in a multi-stage manner in registry with one another in the direction of the depth of the cryopump and are disposed in parallel relation to one another. Each of the cryopanels is disposed adjacent to a rear surface of respective radiation-heat shield plates facing away from the gas inlet. With this construction, the gas molecules reflected by those radiation-heat shield plates and by a rear wall of the cryopump, are less liable to reach the gas inlet, and tend to be condensed at an increased rate on those cryopanels.

Cryopump

A plurality of winding units each composed of a wire element are serially arranged in the axial direction of the winding between an inner insulating sleeve and an outer insulating sleeve, and vertical cooling paths are formed on opposite sides of each winding unit and horizontal cooling paths are formed between adjacent winding units. The winding units are divided into a plurality of winding sub-units to define a central vertical cooling path therebetween, which central vertical cooling path includes a via flow path and a branch inducing flow path, whereby cooling fluid flows in opposite directions and at substantially the same speed in the horizontal cooling paths along upper and lower surfaces of each of the winding units having the branch inducing flow path. In this manner, the entire winding is uniformly cooled.

Electrical apparatus winding

Winding structure for static electrical induction apparatus such as transformers, reactors, or the like. A winding assembly is disposed in a space formed between a pair of inner and outer insulation continuous walls which are disposed in a container so as to commonly include the vertical axis of the container thereby defining the space therebetween. An inner vertical coolant passage is formed between the winding assembly and the inner insulation wall and an outer vertical coolant passage is also formed between the winding assembly and the inner insulation wall. The winding assembly is composed of a plurality of coil units stacked on one another in the vertical direction with separation at predetermined intervals so as to form horizontal coolant passages between vertically adjacent ones of the coil units, the inner and outer vertical coolant passages communicating with each other through the horizontal coolant passages. A plurality of coolant flow control members are disposed in discrete relation from one another in at least selected one of the inner and outer vertical coolant passages in a manner so that a horizontal sectional area of the selected vertical coolant passage is decreased periodically at a pitch of nP along the vertical direction where n represents an integer which is not smaller than two (2) and P represents a pitch of the coil units along the vertical direction. Further, each of the coil units may be divided into at least two, inner and outer, coil sub-units disposed concentrically with each other in a common horizontal plane to thereby additionally form an intermediate vertical coolant passage between the vertically stacked inner coil sub-units and the vertically stacked outer coil sub-units. The coolant flow control members are disposed only in this intermediate vertical coolant passage to decrease periodically the horizontal sectional area thereof at the pitch of nP in the same manner as mentioned above.

Winding structure for static electrical induction apparatus

A plurality of winding units mounted about a magnetic core structure, each of which consisting of wound wire elements, are disposed and stacked in an annular space defined by a coaxial inner and outer insulating sleeves, so as to form a winding structure for electric devices. Vertical passages for cooling fluid are defined at both sides of the winding units, while horizontal passages for the cooling fluid are formed between adjacent winding units. A plurality of peripherally continuous flow controlling bodies are disposed in either one of the vertical passages at a two vertical pitches of the winding unit, so as to confront alternating ones of the winding units. Alternatively, the flow controlling bodies are disposed alternatingly in both vertical passages, in such a manner that the flow controlling bodies disposed in one of the vertical passages confront alternating ones of said winding units which are not confronted by the flow controlling bodies disposed in the other vertical passage. These flow controlling bodies are effective to induce flows of the cooling fluid in opposite directions and of substantially same velocity, in two horizontal passages separated by the winding unit which is confronted by the flow controlling body.

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Hitachi, Japan

Taisei Uede