Refrigeration apparatus with a refrigerant collection operation between a plurality of outdoor units

Patent metadata

Field	Value
Publication number	US-9010135-B2
Application number	US-52445408-A
Country	US
Kind code	B2
Filing date	Jan 11, 2008
Priority date	Jan 26, 2007
Publication date	Apr 21, 2015
Grant date	Apr 21, 2015

Abstract

To a refrigerant circuit of an air conditioner as a refrigerating apparatus, a plurality of outdoor units are connected. In an operation state where the first outdoor unit is operated with the second outdoor unit stopped, the air conditioner performs refrigerant collection operation for collecting and retaining surplus refrigerant to and in a second outdoor heat exchanger of the second outdoor unit. During the refrigerant collection operation, a second outdoor expansion valve is closed fully, and a second outdoor fan is operated. Part of refrigerant discharged from a first compressor flows into the second outdoor heat exchanger during the refrigerant collection operation. The refrigerant flowing in the second outdoor heat exchanger dissipates heat to outdoor air to be condensed. Since the second outdoor expansion valve is closed fully, the condensed refrigerant is retained in the second outdoor heat exchanger.

First claim

The invention claimed is:

1. A refrigerating apparatus, comprising: a refrigerant circuit including a plurality of outdoor units each having a compressor and a heat source side heat exchanger, and a plurality of indoor units each having a user side heat exchanger, the outdoor units and the indoor units connected to one another, wherein the refrigerating apparatus is configured to perform a refrigeration cycle in the refrigerant circuit, each of the outdoor units includes: a heat source side expansion valve for adjusting a flow rate of refrigerant in one end side of the heat source side heat exchanger of each of the outdoor units; and a high pressure sensor for detecting a pressure of the refrigerant, which is in a state of high pressure, discharged from the compressor of each of the outdoor units; the refrigerating apparatus is capable of performing low power operation in which, in each of some of the outdoor units, the compressor is in an operating state, and in at least one of the others of the outdoor units, the compressor is in a non-operating state, and refrigerant collection operation for collecting and retaining refrigerant to and in a non-operating heat exchanger, which is the heat source side heat exchanger of one of the outdoor units having the compressor in the non-operating state in the low power operation, by supplying a cooling fluid for cooling the refrigerant to the non-operating heat exchanger, the operation being performed in a state where refrigerant flow on one end side of the non-operating heat exchanger is limited or blocked by the heat source side expansion valve of one of the outdoor units having the compressor in the non-operating state in the low power operation, while refrigerant flow on another end side of the non-operating heat exchanger is communicating with a discharge side of the compressor in the operating state in the low power operation, a controller configured to adjust, during the refrigerant collection operation, a flow rate of the cooling fluid supplied to the non-operating heat exchanger on the basis of a detected value of the high pressure sensor of one of the outdoor units having the compressor in the operating state during the refrigerant collection operation.

2. The apparatus of claim 1 , wherein the heat source side heat exchanger of each of the outdoor units is configured to heat exchange the refrigerant with outdoor air, each of the outdoor units has an outdoor fan provided for supplying outdoor air to the heat source side heat exchanger of each of the outdoor units, and the controller is configured to adjust, during the refrigerant collection operation, a flow rate of the outdoor air supplied as the cooling fluid to the non-operating heat exchanger by controlling operation of the outdoor fan of one of the outdoor units having the compressor in the non-operating state.

3. The apparatus of claim 1 , wherein the refrigerant collection operation collects and retains refrigerant to and in the heat source side heat exchanger of one of the outdoor units having the compressor in the non-operating state without a receiver to collect and retain refrigerant therein in the low power operation.

4. A refrigerating apparatus, comprising:
a refrigerant circuit including a compressor, a plurality of heat source side heat exchangers, and at least one user side heat exchanger connected to one another, wherein
the refrigerating apparatus is capable of performing low power operation for performing a refrigeration cycle in the refrigerant circuit in a state where at least one of the heat source side heat exchangers is in a non-operating state, and refrigerant collection operation for collecting and retaining refrigerant to and in the heat source side heat exchanger in the non-operating state in the low power operation, and
the refrigerant circuit includes multiple ones of the at least one user side heat exchanger, heat source side expansion valves provided one by one at one ends of the heat source side heat exchangers, user side expansion valves provided one by one at one ends of the user side heat exchangers, and a liquid side pipe having one branching end connected to the heat source side expansion valves, and another branching end connected to the user side expansion valves,
the apparatus comprising:
a controller configured to perform, in an operation state where at least one of the heat source side heat exchangers functions as a condenser, adjustment of an opening of a heat source side expansion valve that corresponds to the heat source side heat exchanger functioning as a condenser in response to a sensed high side pressure of the refrigerant cycle, a sensed pressure of the refrigerant in the liquid side pipe and a sensed low side pressure of the refrigerant cycle, so that a difference between the sensed high side pressure of the refrigeration cycle and the sensed pressure of the refrigerant in the liquid side pipe is equal to or larger than a predetermined first reference value and a difference between the sensed pressure of the refrigerant in the liquid side pipe and the sensed low side pressure of the refrigeration cycle is equal to or larger than a predetermined second reference value.

5. The apparatus of claim 4 , wherein
the refrigerant collection operation collects and retains refrigerant to and in the heat source side heat exchanger in the non-operating state without a receiver to collect and retain refrigerant therein in the low power operation.

Assignees

• Kawano Satoshi
• Matsuoka Shinya
• Daikin Ind Ltd

Inventors

• Kawano Satoshi
• Matsuoka Shinya

Classifications

• F25B2600/05

  Refrigerant levels · CPC title

• F25B13/00 Primary

  Compression machines, plants or systems, with reversible cycle (defrosting cycles F25B47/02) · CPC title

• F25B2313/005

  Outdoor unit expansion valves · CPC title

• F25B2400/19

  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 title

• F25B2313/0231

  with simultaneous cooling and heating · CPC title