Heat source unit and refrigeration system

• US 8,297,073 B2
• Filed: 01/30/2008
• Issued: 10/30/2012
• Est. Priority Date: 01/31/2007
• Status: Expired due to Fees

• Current Assignee: Daikin Industries Ltd
• Original Assignee: Daikin Industries Ltd
• Inventors: Kawano, Satoshi, Matsuoka, Shinya, Oka, Masahiro, Mizutani, Kazuhide
• Primary Examiner(s): Ali, Mohammad
• Application Number:
  US12/525,203
• Publication Number:
  US 20100089085A1
• Time in Patent Office: 1,735 Days
• Field of Search: 624/68, 622/386, 624/70, 622/283, 625/13, 622/387, 623/241, 621/60, 625/09, 625/12, 621/29, 621/26
• US Class Current: 62/468
• CPC Class Codes: F25B 13/00 Compression machines, plants or systems, with reversible cycle defrosting cycles F25B47/02
• CPC Class Codes: F25B 2313/023 using multiple indoor units
• CPC Class Codes: F25B 2313/02732 using two three-way valves
• CPC Class Codes: F25B 2400/075 with parallel compressors
• CPC Class Codes: F25B 2400/13 Economisers
• CPC Class Codes: F25B 2400/16 Receivers
• CPC Class Codes: F25B 2400/19 Pumping down refrigerant from one part of the cycle to another part of the cycle, e.g. when the cycle is changed from cooling to heating, or before a defrost cycle is started
• CPC Class Codes: F25B 2500/02 Increasing the heating capacity of a reversible cycle during cold outdoor conditions
• CPC Class Codes: F25B 45/00 Arrangements for charging or discharging refrigerant

Abstract

An outdoor unit (20) including a compressor (21) and an outdoor heat exchanger (22) and an indoor unit (30) including an indoor heat exchanger (31) are provided. The outdoor unit (20) and the indoor unit (30) constitute a main circuit (43) of a refrigerant circuit (40). A sub-circuit (70) whose one end is connected to a liquid line (4a) of the main circuit (43) and another end is connected to a low-pressure gas line (4b) of the main circuit (43), and which stores refrigerant in the main circuit (43) is also provided. The sub-circuit (70) is located on a sub-passageway (71), and includes: a refrigerant regulator (72) for storing refrigerant in the main circuit (43); and a switch mechanism (73) for establishing and blocking communication between the refrigerant regulator (72) and each of the liquid line (4a) and the low-pressure gas line (4b). When the amount of refrigerant in the main circuit (43) is excessive, redundant refrigerant in the main circuit (43) is stored in the refrigerant regulator (72).

Claims

1. A refrigeration system comprising:

a heat source unit, said heat source unit comprising;

a compressor to which a low-pressure gas line is connected;

a heat-source side heat exchanger whose one end communicates with the compressor and another end is connected to a liquid line; and

a sub-circuit whose one end is connected to the liquid line and another end is connected to the low-pressure gas line, wherein

the compressor, the low-pressure gas line, the heat-source side heat exchanger, and the liquid line constitute a portion of a main circuit of a refrigerant circuit,

the sub-circuit is separated from the main circuit, and stores refrigerant in the main circuit,

the sub-circuit includes;

a sub-passageway whose one end is connected to the liquid line and another end is connected to the low-pressure gas line;

a refrigerant regulator provided on the sub-passageway and storing refrigerant in the main circuit; and

a switch mechanism configured to establish and block communication between the refrigerant regulator and each of the liquid line and the low-pressure gas line,

the main circuit of the refrigerant circuit is configured by connecting a utilization unit including a utilization side heat exchanger to the heat source unit,

the refrigeration system includes a refrigerant-amount controlling device configured to control the switch mechanism such that when an amount of refrigerant in the main circuit is excessive, redundant refrigerant in the main circuit is stored in the refrigerant regulator, and

the refrigerant-amount controlling device being configured to determine whether an amount of refrigerant in the main circuit is excessive or not, based on a degree of supercooling in one of the heat-source side heat exchanger and the utilization side heat exchanger which serves as a condenser.

2. The refrigeration system of claim 1, wherein the refrigerant-amount controlling device controls the switch mechanism such that when the main circuit is deficient in refrigerant, refrigerant in an amount corresponding to the deficiency is supplied from the refrigerant regulator to the main circuit.

3. The refrigeration system of claim 1, wherein the refrigerant-amount controlling device is configured to determine whether the main circuit is deficient in refrigerant or not, based on a degree of supercooling in one of the heat-source side heat exchanger and the utilization side heat exchanger which serves as a condenser.

4. The refrigeration system of claim 1, further comprising:

an oil separator provided at a discharge side of the compressor;

an oil return passageway for returning oil in the oil separator to the compressor; and

an oil introducing pipe connecting the oil return passageway and the refrigerant regulator to each other, and capable of establishing and blocking communication with the oil introducing pipe.