Mayekawa Mfg. Co., Ltd.

The Doshisha

Nelson Mugabi

Choiku Yoshikawa

Hiroshi Yamaguchi

Masato Takeda

Yuki Matsumoto

Katsumi Fujima

Yasushi Tomiyama

Daiki Kayashima

Toshio Kutsuna

Nobuo Oosuga

A defrost system includes a thermosiphon defrost circuit that is provided by being branched from a circulation line, in which, at the time of defrosting, a COrefrigerant staying inside a fin-tube heat exchanger repeats a two-phase change of a gaseous form and reliquefaction, and which forms a COcirculation path together with the fin-tube heat exchanger; electromagnetic opening/closing valves that are closed at the time of defrosting and set the COcirculation path to a closed circuit; and a first electric heater arranged above the thermosiphon defrost circuit so as to be adjacent to the thermosiphon defrost circuit, and naturally circulates the COrefrigerant in the closed circuit at the time of defrosting.

Defrost system which utilizes electric heater for thermosiphon

A plate stack includes a plurality of plates, each including corrugated portions formed on front and back surfaces thereof. First and second heat exchange flow passages are formed between plates, arranged alternately along stacking direction of the plates. Each plate has two through holes penetrating the front and back surfaces, through which the first heat exchange fluid is introduced and derived. The plate stack includes first partition weirs formed on at least one of two plate surfaces, the two plate surfaces forming a corresponding one of the first heat exchange flow passages therebetween. First partition weirs are symmetrically and obliquely arranged with respect to a center line connecting centers of two through holes as viewed from the stacking direction. A flow passage is formed along the center line on a side of at least one of the two through holes, from which first heat exchange fluid is introduced.

Plate stack and heat exchanger

A COcooling and heating apparatus and method permit simultaneous production of high-temperature heat source and low-temperature heat source having a temperature difference therebetween. The apparatus/method uses CO(carbon dioxide) as a refrigerant, and has a first refrigerating cycle circuit where the refrigerant is compressed to a supercritical zone and then decompressed via an expansion device to a pressure/temperature level of the COtriple point or below to thereby attain evaporation. The apparatus can include multistage compressors, intermediate cooler disposed in a first refrigerant flow path between a condenser and the expansion device. A second refrigerating cycle circuit having a second refrigerant flow path, which can branch off from the first refrigerant flow path or provided in an independent closed circuit, can be provided to carry out absorption of evaporation latent heat with the first refrigerant flow path to thereby maintain the pressure/temperature level of the COtriple point (Ptr) or above. A third refrigerating cycle circuit having a third refrigerant flow path also can be provided to carry out heat exchange with the second refrigerant flow path.

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Growing community of inventors

Ryugasaki, Japan

Nelson Mugabi