COMBINED CASCADE REFRIGERATION CYCLE APPARATUS

• US 20140165642A1
• Filed: 02/21/2014
• Published: 06/19/2014
• Est. Priority Date: 08/22/2011
• Status: Active Grant

• Current Assignee: Toshiba Carrier Corporation (Carrier Global Corporation)
• Original Assignee: Toshiba Carrier Corporation (Carrier Global Corporation)
• Inventors: ASARI, Shun, ZUSHI, Takahiro, ENDO, Takahisa
• Granted Patent: US 9,395,107 B2
• Time in Patent Office: Days
• US Class Current: 62/335
• CPC Class Codes: F25B 13/00 Compression machines, plants or systems, with reversible cycle defrosting cycles F25B47/02
• CPC Class Codes: F25B 2339/047 Water-cooled condensers
• CPC Class Codes: F25B 2347/021 Alternate defrosting
• CPC Class Codes: F25B 2400/06 Several compression cycles arranged in parallel
• CPC Class Codes: F25B 30/02 of the compression type
• CPC Class Codes: F25B 47/025 by reversing the cycle
• CPC Class Codes: F25B 7/00 Compression machines, plants or systems, with cascade operation, i.e. with two or more circuits, the heat from the condenser of one circuit being absorbed by the evaporator of the next circuit F25B9/00 takes precedence

Abstract

According to one embodiment, an apparatus includes a housing, two high-temperature-side refrigeration circuits and two low-temperature-side refrigeration circuits. Each of the high-temperature-side refrigeration circuits is configured to exchange heat with both of the two low-temperature-side refrigeration circuits by cascade heat exchangers. A hot-water pipe letting water or hot water through water-refrigerant heat exchangers of the high-temperature-side refrigeration circuits is provided. When the low-temperature-side refrigeration circuit conducts a defrosting operation of the evaporator, the low-temperature-side refrigeration circuits are controlled in such a way that the low-temperature-side refrigerant circuit releases heat in the cascade heat exchanger.

Claims

1. A combined cascade refrigeration cycle apparatus, comprising:

two high-temperature-side refrigeration circuits mounted on a housing, each of the two high-temperature-side refrigeration circuits comprising a water-refrigerant heat exchanger which conducts heat exchange of a refrigerant discharged from a high-temperature-side compressor for water;

two low-temperature-side refrigeration circuits mounted on the housing, each of the two low-temperature-side refrigeration circuits comprising an evaporator composed of an air heat exchanger, wherein each of the two high-temperature-side refrigeration circuits is configured to exchange heat with each of the two low-temperature-side refrigeration circuits by a cascade heat exchanger; and

a hot-water pipe letting water or hot water through a water-side flow channel of the water-refrigerant heat exchanger of each of the high-temperature-side refrigeration circuits, wherein

the two low-temperature-side refrigeration circuits are controlled in such a way that, when one of the low-temperature-side refrigeration circuits conducts a defrosting operation of its evaporator, the other low-temperature-side refrigerant circuit releases heat in the cascade heat exchanger.

2. The combined cascade refrigeration cycle apparatus of claim 1, wherein

the cascade heat exchanger comprises a high-temperature refrigerant flow channel communicating with each of the high-temperature-side refrigeration circuits, a first low-temperature refrigerant flow channel communicating with one of the low-temperature-side refrigeration circuits, and a second low-temperature refrigerant flow channel communicating with the other low-temperature-side refrigeration circuit, and is structured by a plate type heat exchanger comprising the first low-temperature refrigerant flow channel on a surface side of the high-temperature refrigerant flow channel and the second low-temperature refrigerant flow channel on another surface side.

3. The combined cascade refrigeration cycle apparatus of claim 1, wherein

the water-refrigerant heat exchangers of the two high-temperature-side refrigeration circuits are formed as one unit, comprises a water-side flow channel connected to the hot-water pipe, a first refrigerant-side flow channel communicating with one of the high-temperature-side refrigeration circuits, and a second refrigerant-side flow channel communicating with the other high-temperature-side refrigeration circuit, and is structured by a plate type heat exchanger comprising the first refrigerant-side flow channel on one surface side of the water-side flow channel and the second refrigerant-side flow channel on the other surface side.

4. The combined cascade refrigeration cycle apparatus of claim 1, the apparatus being controlled so as to simultaneously decrease cascade heat exchanger temperature of a first high-temperature-side refrigeration circuit and a second high-temperature-side refrigeration circuit, and obtain reduction in a heating performance, by stopping one of a low-temperature-side compressor in a first low-temperature-side refrigeration circuit and a low-temperature-side compressor in a second low-temperature-side refrigeration circuit when a requesting performance is deteriorated because of increase in external temperature or decrease in heating load.