AIR-CONDITIONING APPARATUS

• US 20140223940A1
• Filed: 12/16/2011
• Published: 08/14/2014
• Est. Priority Date: 12/16/2011
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Morimoto, Osamu, Shimamoto, Daisuke, Azuma, Koji, Honda, Takayoshi
• Granted Patent: US 10,544,973 B2
• Time in Patent Office: Days
• US Class Current: 62/183
• CPC Class Codes: F24D 19/1039 the system uses a heat pump
• CPC Class Codes: F24D 2200/123 Compression type heat pumps
• CPC Class Codes: F24D 3/18 using heat pumps
• CPC Class Codes: F24F 3/065 with a plurality of evaporators or condensers
• CPC Class Codes: F25B 13/00 Compression machines, plants or systems, with reversible cycle defrosting cycles F25B47/02
• CPC Class Codes: F25B 2313/006 two pipes connecting the outdoor side to the indoor side with multiple indoor units
• CPC Class Codes: F25B 2313/023 using multiple indoor units
• CPC Class Codes: F25B 2313/0231 with simultaneous cooling and heating
• CPC Class Codes: F25B 2313/0272 using bridge circuits of one-way valves
• CPC Class Codes: F25B 2313/02741 using one four-way valve
• CPC Class Codes: F25B 2313/0315 Temperature sensors near the outdoor heat exchanger
• CPC Class Codes: F25B 2600/02 Compressor control
• CPC Class Codes: F25B 41/385 Dispositions with two or more expansion means arranged in parallel on a refrigerant line leading to the same evaporator
• CPC Class Codes: F25B 49/027 Condenser control arrangements
• CPC Class Codes: Y02B 30/12 Hot water central heating systems using heat pumps

Abstract

An air-conditioning apparatus includes a refrigeration cycle that includes an intermediate heat exchanger configured to exchange heat between a heat source side refrigerant and a heat medium different from the heat source side refrigerant, a heat medium circuit that includes at least one pump configured to circulate the heat medium related to heat exchange in the intermediate heat exchanger, a use side heat exchanger configured to exchange heat between the heat medium and air related to an air-conditioned space, and flow switching valves. A controller is configured to perform control to activate the pump to circulate the heat medium through the heat medium circuit when, during suspension of an air conditioning operation, the detected temperature of outdoor air is at or below a first predetermined temperature and a first predetermined period of time has elapsed since the pump was stopped.

Claims

1. An air-conditioning apparatus comprising:

a refrigeration cycle that includes a compressor configured to compress a heat source side refrigerant, a refrigerant flow switching device configured to switch between paths for circulation of the heat source side refrigerant, a heat source side heat exchanger configured to allow the heat source side refrigerant to exchange heat, an expansion device configured to regulate a pressure of the heat source side refrigerant, and at least one intermediate heat exchanger configured to exchange heat between the heat source side refrigerant and a heat medium different from the heat source side refrigerant, the compressor, the refrigerant flow switching device, the heat source side heat exchanger, the expansion device, and the intermediate heat exchanger being connected by pipes;

a heat medium circuit that includes at least one pump configured to circulate the heat medium related to heat exchange in the intermediate heat exchanger, a use side heat exchanger configured to exchange heat between the heat medium and air related to an air-conditioned space, and a flow switching valve configured to switch between a passage for the heated heat medium through the use side heat exchanger and a passage for the cooled heat medium therethrough, the pump, the use side heat exchanger, and the flow switching valve being connected by pipes;

an outdoor air temperature detection device configured to detect the temperature of outdoor air; and

a controller configured to, when determining during suspension of an operation related to air conditioning that the temperature detected by the outdoor air temperature detection device is at or below a first predetermined temperature and a first predetermined period of time has elapsed since the pump was stopped, perform control such that the pump is activated to circulate the heat medium through the heat medium circuit.

2. The air-conditioning apparatus of claim 1, wherein when determining after the activation of the pump that the temperature of the heat medium is at or above a second predetermined temperature, the controller performs control such that the pump is stopped.

3. The air-conditioning apparatus of claim 1, further comprising

an air-conditioned temperature detection device configured to detect the temperature of air flowing into the use side heat exchanger,

wherein the controller drives a fan for the use side heat exchanger until the controller determines after the activation of the pump that the temperature detected by the air-conditioned temperature detection device is at or below a third predetermined temperature.

4. The air-conditioning apparatus of claim 1, wherein the controller performs control after the activation of the pump such that the refrigeration cycle is operated to heat the heat medium.

5. The air-conditioning apparatus of claim 4, wherein when the refrigeration cycle is operated, a target pressure in high-pressure-side part of the refrigeration cycle is set lower than a pressure during a normal operation, or alternatively an upper limit capacity of the compressor in the refrigeration cycle is set lower than a capacity during the normal operation.

6. The air-conditioning apparatus of claim 4, wherein when determining that driving time of the compressor after the activation of the pump is a second predetermined period of time or longer, the controller stops the pump and then allows the heat source side heat exchanger to defrost.

7. The air-conditioning apparatus of claim 1, wherein the controller sets the first predetermined period of time on a basis of the temperature of the outdoor air.

8. The air-conditioning apparatus of claim 2, wherein the controller sets the second predetermined temperature on a basis of the temperature of the outdoor air.

9. The air-conditioning apparatus of claim 2, further comprising

an air-conditioned temperature detection device configured to detect the temperature of air flowing into the use side heat exchanger,

wherein the controller drives a fan for the use side heat exchanger until the controller determines after the activation of the pump that the temperature detected by the air-conditioned temperature detection device is at or below a third predetermined temperature.

10. The air-conditioning apparatus of claim 2, wherein the controller performs control after the activation of the pump such that the refrigeration cycle is operated to heat the heat medium.

11. The air-conditioning apparatus of claim 3, wherein the controller performs control after the activation of the pump such that the refrigeration cycle is operated to heat the heat medium.

12. The air-conditioning apparatus of claim 10, wherein when the refrigeration cycle is operated, a target pressure in high-pressure-side part of the refrigeration cycle is set lower than a pressure during a normal operation, or alternatively an upper limit capacity of the compressor in the refrigeration cycle is set lower than a capacity during the normal operation.

13. The air-conditioning apparatus of claim 11, wherein when the refrigeration cycle is operated, a target pressure in high-pressure-side part of the refrigeration cycle is set lower than a pressure during a normal operation, or alternatively an upper limit capacity of the compressor in the refrigeration cycle is set lower than a capacity during the normal operation.

14. The air-conditioning apparatus of claim 5, wherein when determining that driving time of the compressor after the activation of the pump is a second predetermined period of time or longer, the controller stops the pump and then allows the heat source side heat exchanger to defrost.

15. The air-conditioning apparatus of claim 2, wherein the controller sets the first predetermined period of time on a basis of the temperature of the outdoor air.

16. The air-conditioning apparatus of claim 3, wherein the controller sets the first predetermined period of time on a basis of the temperature of the outdoor air.

17. The air-conditioning apparatus of claim 4, wherein the controller sets the first predetermined period of time on a basis of the temperature of the outdoor air.

18. The air-conditioning apparatus of claim 5, wherein the controller sets the first predetermined period of time on a basis of the temperature of the outdoor air.

19. The air-conditioning apparatus of claim 6, wherein the controller sets the first predetermined period of time on a basis of the temperature of the outdoor air.