CASCADE REFRIGERATION CYCLE APPARATUS

• US 20140013790A1
• Filed: 09/17/2013
• Published: 01/16/2014
• Est. Priority Date: 03/18/2011
• Status: Active Grant

• Current Assignee: Toshiba Carrier Corporation (Carrier Global Corporation)
• Original Assignee: Toshiba Carrier Corporation (Carrier Global Corporation)
• Inventors: ASARI, Shun, ZUSHI, Takahiro
• Granted Patent: US 9,593,869 B2
• Time in Patent Office: Days
• US Class Current: 62/335
• CPC Class Codes: F25B 1/00 Compression machines, plants or systems with non-reversible cycle F25B3/00, F25B5/00, F25B6/00, F25B7/00, F25B9/00 take precedence
• CPC Class Codes: F25B 13/00 Compression machines, plants or systems, with reversible cycle defrosting cycles F25B47/02
• CPC Class Codes: F25B 2313/02742 using two four-way valves
• CPC Class Codes: F25B 2400/0401 for the compressor
• CPC Class Codes: F25B 2500/26 characterised by the startup of the refrigeration cycle
• CPC Class Codes: F25B 2600/021 Inverters therefor
• CPC Class Codes: F25B 2600/0261 external to the compressor
• CPC Class Codes: F25B 2700/1931 Discharge pressures
• CPC Class Codes: F25B 2700/1933 Suction pressures
• CPC Class Codes: F25B 2700/2106 of fresh outdoor air
• CPC Class Codes: F25B 2700/21151 at the suction side of the compressor
• CPC Class Codes: F25B 2700/21152 at the discharge side of the compressor
• CPC Class Codes: F25B 2700/21161 of the fluid heated by the condenser
• CPC Class Codes: F25B 47/025 by reversing the cycle
• CPC Class Codes: F25B 49/025 Motor control arrangements
• 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
• CPC Class Codes: Y02B 30/70 Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating

Abstract

According to one embodiment, a cascade refrigeration cycle apparatus according to the present embodiment includes a high-temperature-side and a low-temperature-side refrigeration circuits, an inverter and a control section. The high-temperature-side refrigeration circuit includes a first compressor and a cascade heat exchanger. The low-temperature-side refrigeration circuit includes a second compressor and the cascade heat exchanger. The inverter connected to at least one of the compressors. The control section controls the inverter so that a set operating frequency for the first compressor is higher than a set operating frequency for the second compressor when an operation of the apparatus is started.

Claims

1. A cascade refrigeration cycle apparatus comprising:

a high-temperature-side refrigeration circuit including a high-temperature-side compressor, a high-temperature-side condenser, a high-temperature-side expander, and a cascade heat exchanger which are in communication with one another via refrigerant piping;

a low-temperature-side refrigeration circuit including a low-temperature-side compressor, the cascade heat exchanger, a low-temperature-side expander, and an air-heat exchanger which are in communication with one another via refrigerant piping, the low-temperature-side refrigeration circuit being mounted in an identical housing in which the high-temperature-side refrigeration circuit is mounted;

an inverter connected to at least one of the high-temperature-side compressor of the high-temperature-side refrigeration circuit and the low-temperature-side compressor of the low-temperature-side refrigeration circuit; and

control section which controls the inverter so that a set operating frequency for the high-temperature-side compressor is higher than a set operating frequency for the low-temperature-side compressor when an operation of the apparatus is started.

2. The apparatus according to claim 1, wherein

the high-temperature-side refrigeration circuit includes a bypass circuit allowing for communication between a high-pressure piping system which is refrigerant piping extending from the high-temperature-side compressor through the high-temperature-side condenser to the high-temperature-side expander and a low-pressure piping system which is refrigerant piping extending from the high-temperature-side expander through the cascade heat exchanger to the high-temperature-side compressor, the bypass circuit includes an opening and closing unit in a middle portion thereof, and

the control section opens the opening and closing unit of the bypass circuit to allow the high-pressure piping system and the low-pressure piping system to communicate with each other when the operation of the apparatus is started, and actuates the high-temperature-side compressor after actuating the low-temperature-side compressor.

3. The apparatus according to claim 1, wherein

the control section maintains the operating frequencies of the compressors for a predetermined time after the operating frequencies of the compressors are reached to the set operating frequencies, when the operation of the apparatus is started.

4. The apparatus according to claim 1, wherein

the control section actuates the low-temperature-side compressor first, and when a predetermined time has elapsed subsequent to the actuation of the low-temperature-side compressor, or when a high-pressure-side pressure in the low-temperature-side refrigeration circuit has reached a predetermined value or greater, or when a pressure in the high-temperature-side refrigeration circuit has reached a predetermined value or greater, actuates the high-temperature-side compressor.

5. The apparatus according to claim 1, wherein

the apparatus is a plurality of cascade refrigeration cycles, and

the control section sequentially actuates the cascade refrigeration cycles by delaying each of the cascade refrigeration cycles by a predetermined time.

6. The apparatus according to claim 2, wherein

the apparatus is a plurality of cascade refrigeration cycles, and

the control section sequentially actuates the cascade refrigeration cycles by delaying each of the cascade refrigeration cycles by a predetermined time.

7. The apparatus according to claim 3, wherein

the apparatus is a plurality of cascade refrigeration cycles, and

the control section sequentially actuates the cascade refrigeration cycles by delaying each of the cascade refrigeration cycles by a predetermined time.

8. The apparatus according to claim 4, wherein

the apparatus is a plurality of cascade refrigeration cycles, and

the control section sequentially actuates the cascade refrigeration cycles by delaying each of the cascade refrigeration cycles by a predetermined time.