AIR CONDITIONER

• US 20090151374A1
• Filed: 12/12/2006
• Published: 06/18/2009
• Est. Priority Date: 12/16/2005
• Status: Active Grant

• Current Assignee: Daikin Industries Ltd
• Original Assignee: Daikin Industries Ltd
• Inventors: Kasahara, Shinichi
• Granted Patent: US 9,303,908 B2
• Time in Patent Office: Days
• US Class Current: 62/149
• CPC Class Codes: F25B 13/00 Compression machines, plants or systems, with reversible cycle defrosting cycles F25B47/02
• CPC Class Codes: F25B 2313/0233 in parallel arrangements
• CPC Class Codes: F25B 2313/02741 using one four-way valve
• CPC Class Codes: F25B 2400/13 Economisers
• CPC Class Codes: F25B 49/005 of safety devices F25B49/02 and F25B49/04 take precedence

Abstract

An air conditioner includes a refrigerant circuit configured to interconnect a heat source unit and a utilization unit, a transmission line that exchanges a signal between the heat source unit and the utilization unit, an information obtaining section, an operation controlling section capable of performing a refrigerant quantity judging operation, a refrigerant quantity judging section, and a condition setting section. The information obtaining section obtains information on the utilization unit connected to the heat source unit via the transmission line. The refrigerant quantity judging section judges the adequacy of the refrigerant quantity in the refrigerant circuit by using the operation state quantity of constituent equipment or refrigerant flowing in the refrigerant circuit in the refrigerant quantity judging operation. The condition setting section sets a condition for the refrigerant quantity judging operation according to the information on the utilization unit obtained by the information obtaining section.

Claims

1. An air conditioner, comprising:

a refrigerant circuit configured to interconnect a heat source unit and a utilization unit;

a transmission line configured to exchange a signal between the heat source unit and the utilization unit;

an information obtaining section configured to obtain information on the utilization unit connected to the heat source unit via the transmission line;

an operation controlling section configured to perform a refrigerant quantity judging operation;

a refrigerant quantity judging section configured to judge adequacy of a refrigerant quantity in the refrigerant circuit by using an operation state quantity of constituent equipment or refrigerant flowing in the refrigerant circuit in the refrigerant quantity judging operation; and

a condition setting section configured to set a condition for the refrigerant quantity judging operation according to the information on the utilization unit obtained by the information obtaining section.

2. The air conditioner according to claim 1, further comprising

a refrigerant quantity calculating section configured to calculate a refrigerant quantity in the refrigerant circuit from an operation state quantity of constituent equipment or refrigerant flowing in the refrigerant circuit in the refrigerant quantity judging operation by using at least one relational expression between a refrigerant quantity in the refrigerant circuit and an operation state quantity of constituent equipment or refrigerant flowing in the refrigerant circuit, wherein

the refrigerant quantity judging section judges the adequacy of the refrigerant quantity in the refrigerant circuit by using the refrigerant quantity in the refrigerant circuit calculated by the refrigerant quantity calculating section, and

the condition setting section sets the relational expression as a condition for the refrigerant quantity judging operation, according to a model of the utilization unit obtained by the information obtaining section.

3. The air conditioner according to claim 2, wherein

relational expressions are provided separately for the utilization unit and portions other than the utilization unit, and

the condition setting section sets relational expressions provided for the refrigerant quantity in the utilization unit according to a model of the utilization unit obtained by the information obtaining section.

4. The air conditioner according to claim 1, wherein

the condition setting section sets a target control value of constituent equipment in the refrigerant quantity judging operation as a condition for the refrigerant quantity judging operation according to the capacity of the utilization unit.

5. The air conditioner according to claim 4, wherein

the heat source unit includes a compressor and a heat source side heat exchanger,

the utilization unit includes an expansion mechanism and a utilization side heat exchanger,

the refrigerant circuit is configured to interconnect the compressor, the heat source side heat exchanger, the expansion mechanism, and the utilization side heat exchanger, and

the operation controlling section causes the utilization side heat exchanger to function as an evaporator for refrigerant and also controls constituent equipment such that a pressure of refrigerant sent from the utilization side heat exchanger to the compressor or an operation state quantity equivalent to such pressure becomes constant at a target low pressure used as the target control value in the refrigerant quantity judging operation.

6. The air conditioner according to claim 4, wherein

the heat source unit includes a compressor and a heat source side heat exchanger,

the utilization unit includes an expansion mechanism and a utilization side heat exchanger,

the refrigerant circuit is configured to interconnect the compressor, the heat source side heat exchanger, the expansion mechanism, and the utilization side heat exchanger, and

the operation controlling section causes the utilization side heat exchanger to function as an evaporator for refrigerant and also controls constituent equipment such that a superheat degree of refrigerant sent from the utilization side heat exchanger to the compressor becomes constant at a target superheat degree used as the target control value in the refrigerant quantity judging operation.

7. The air conditioner according to claim 4, wherein

the heat source unit includes a compressor and a heat source side heat exchanger,

the utilization unit includes an expansion mechanism, a utilization side heat exchanger, and a ventilation fan that supplies air to the utilization side heat exchanger,

the refrigerant circuit is configured to interconnect the compressor, the heat source side heat exchanger, the expansion mechanism, and the utilization side heat exchanger, and

the operation controlling section causes the utilization side heat exchanger to function as an evaporator for refrigerant and also performs control such that an air flow rate of the ventilation fan becomes constant at a target air flow rate used as the target control value in the refrigerant quantity judging operation.

8. The air conditioner according claim 2, wherein

the condition setting section sets a target control value of constituent equipment in the refrigerant quantity judging operation as a condition for the refrigerant quantity judging operation according to the capacity of the utilization unit.

9. The air conditioner according to claim 8, wherein

the heat source unit includes a compressor and a heat source side heat exchanger,

the utilization unit includes an expansion mechanism and a utilization side heat exchanger,

the refrigerant circuit is configured to interconnect the compressor, the heat source side heat exchanger, the expansion mechanism, and the utilization side heat exchanger, and

the operation controlling section causes the utilization side heat exchanger to function as an evaporator for refrigerant and also controls constituent equipment such that a pressure of refrigerant sent from the utilization side heat exchanger to the compressor or an operation state quantity equivalent to such pressure becomes constant at a target low pressure used as the target control value in the refrigerant quantity judging operation.

10. The air conditioner according to claim 8, wherein

the heat source unit includes a compressor and a heat source side heat exchanger,

the utilization unit includes an expansion mechanism and a utilization side heat exchanger,

the refrigerant circuit is configured to interconnect the compressor, the heat source side heat exchanger, the expansion mechanism, and the utilization side heat exchanger, and

the operation controlling section causes the utilization side heat exchanger to function as an evaporator for refrigerant and also controls constituent equipment such that a superheat degree of refrigerant sent from the utilization side heat exchanger to the compressor becomes constant at a target superheat degree used as the target control value in the refrigerant quantity judging operation.

11. The air conditioner according to claim 8, wherein

the heat source unit includes a compressor and a heat source side heat exchanger,

the utilization unit includes an expansion mechanism, a utilization side heat exchanger, and a ventilation fan that supplies air to the utilization side heat exchanger,

the refrigerant circuit is configured to interconnect the compressor, the heat source side heat exchanger, the expansion mechanism, and the utilization side heat exchanger, and

the operation controlling section causes the utilization side heat exchanger to function as an evaporator for refrigerant and also performs control such that an air flow rate of the ventilation fan becomes constant at a target air flow rate used as the target control value in the refrigerant quantity judging operation.

12. The air conditioner according claim 3, wherein

the condition setting section sets a target control value of constituent equipment in the refrigerant quantity judging operation as a condition for the refrigerant quantity judging operation according to the capacity of the utilization unit.

13. The air conditioner according to claim 12, wherein

the heat source unit includes a compressor and a heat source side heat exchanger,

the utilization unit includes an expansion mechanism and a utilization side heat exchanger,

the refrigerant circuit is configured to interconnect the compressor, the heat source side heat exchanger, the expansion mechanism, and the utilization side heat exchanger, and

the operation controlling section causes the utilization side heat exchanger to function as an evaporator for refrigerant and also controls constituent equipment such that a pressure of refrigerant sent from the utilization side heat exchanger to the compressor or an operation state quantity equivalent to such pressure becomes constant at a target low pressure used as the target control value in the refrigerant quantity judging operation.

14. The air conditioner according to claim 12, wherein

the heat source unit includes a compressor and a heat source side heat exchanger,

the utilization unit includes an expansion mechanism and a utilization side heat exchanger,

the refrigerant circuit is configured to interconnect the compressor, the heat source side heat exchanger, the expansion mechanism, and the utilization side heat exchanger, and

the operation controlling section causes the utilization side heat exchanger to function as an evaporator for refrigerant and also controls constituent equipment such that a superheat degree of refrigerant sent from the utilization side heat exchanger to the compressor becomes constant at a target superheat degree used as the target control value in the refrigerant quantity judging operation.

15. The air conditioner according to claim 12, wherein

the heat source unit includes a compressor and a heat source side heat exchanger,

the utilization unit includes an expansion mechanism, a utilization side heat exchanger, and a ventilation fan that supplies air to the utilization side heat exchanger,

the refrigerant circuit is configured to interconnect the compressor, the heat source side heat exchanger, the expansion mechanism, and the utilization side heat exchanger, and

the operation controlling section causes the utilization side heat exchanger to function as an evaporator for refrigerant and also performs control such that an air flow rate of the ventilation fan becomes constant at a target air flow rate used as the target control value in the refrigerant quantity judging operation.