AIR-CONDITIONING APPARATUS

• US 20120204585A1
• Filed: 10/28/2009
• Published: 08/16/2012
• Est. Priority Date: 10/28/2009
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Yamashita, Koji, Morimoto, Hiroyuki, Hatomura, Takeshi
• Granted Patent: US 9,303,904 B2
• Time in Patent Office: Days
• US Class Current: 62/160
• 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 2313/0231 with simultaneous cooling and heating
• CPC Class Codes: F25B 2313/02741 using one four-way valve
• CPC Class Codes: F25B 25/005 using primary and secondary systems
• CPC Class Codes: F25B 5/04 arranged in series
• 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

Abstract

An air-conditioning apparatus capable of achieving energy saving is provided. In the air-conditioning apparatus, even when a switching state of a first refrigerant flow switching device varies, a pressure state of a heat source side refrigerant in a bypass pipe is switched between high and low pressures by second refrigerant flow switching devices and a third refrigerant flow switching device (on-off device).

Claims

1-8. -8. (canceled)

9. An air-conditioning apparatus that includes:

an outdoor unit having a compressor, a first refrigerant flow switching device, and a heat source side heat exchanger;

a heat medium relay unit having a plurality of heat exchangers related to heat medium, a plurality of expansion devices respectively correlated with the heat exchangers related to heat medium, and a plurality of pumps; and

a plurality of use side heat exchangers,

the air-conditioning apparatus having;

a refrigerant cycle that includes the compressor, the first refrigerant flow switching device, the heat source side heat exchanger, the expansion devices, and the heat exchangers related to heat medium; and

a heat medium cycle that includes the heat exchangers related to heat medium, the pumps, and the use side heat exchangers, the heat exchangers related to heat medium each exchanging heat between a heat source side refrigerant and a heat medium,

the air-conditioning apparatus having;

a heating only operation mode in which the heat source side refrigerant in a high-temperature and high-pressure state flows into all of the heat exchangers related to heat medium;

a cooling only operation mode in which the heat source side refrigerant in a low-temperature and low-pressure state flows into all of the heat exchangers related to heat medium; and

a cooling and heating mixed operation mode in which the heat source side refrigerant in the high-temperature and high-pressure state flows into one or some of the heat exchangers related to heat medium to heat the heat medium and the heat source side refrigerant in the low-temperature and low-pressure state flows into one or some of the other heat exchangers related to heat medium to cool the heat medium,

the air-conditioning apparatus comprising;

a bypass pipe, which is disposed in refrigerant inlet side of the heat exchangers related to heat medium in the cooling only operation mode, branching from one end of the heat exchangers related to heat medium to connect the refrigerant inlet side with the other end of each of the heat exchangers related to heat medium;

a second refrigerant flow switching device, which is disposed in refrigerant outlet side of each of the heat exchangers related to heat medium in the cooling only operation mode, switching a passage between a passage connecting to the outdoor unit and the bypass pipe; and

a third refrigerant flow switching device, which is disposed in a passage between the refrigerant inlet side of the heat exchangers related to heat medium in the cooling only operation mode and the branching part of the bypass pipe, opening and closing of the passage, wherein

in response to a switching state of the first refrigerant flow switching device, a pressure state of the heat source side refrigerant in the bypass pipe is switched between high pressure and low pressure,

the heat source side refrigerant does not flow through the bypass pipe in the heating only operation mode and the cooling only operation mode,

the heat source side refrigerant flows through the bypass pipe in the cooling and heating mixed operation mode,

the cooling and heating mixed operation mode including;

a cooling main operation mode in which, while the heat source side refrigerant in the high-temperature and high-pressure state flows into the heat source side heat exchanger, the heat source side refrigerant in the high-temperature and high-pressure state flows into one or some of the heat exchangers related to heat medium to heat the heat medium and the heat source side refrigerant in the low-temperature and low-pressure state flows into one or some of the other heat exchangers related to heat medium to cool the heat medium; and

a heating main operation mode in which, while the heat source side refrigerant in low-temperature and low-pressure state flows into the heat source side heat exchanger, the heat source side refrigerant in the high-temperature and high-pressure state flows into one or some of the heat exchangers related to heat medium to heat the heat medium and the heat source side refrigerant in the low-temperature and low-pressure state flows into one or some of the other heat exchangers related to heat medium to cool the heat medium, the air-conditioning apparatus,

the second refrigerant flow switching devices are in the same switching state in both the cooling only operation mode and the heating only operation mode, and

the second refrigerant flow switching devices corresponding to the heat exchangers related to heat medium for cooling and the second refrigerant flow switching devices corresponding to the heat exchangers related to heat medium for heating are in opposite switching states, which show to select the bypass pipe or the passage connecting to the outdoor unit, in both the cooling main operation mode and the heating main operation mode.

10. The air-conditioning apparatus of claim 9, wherein

the heat exchangers related to heat medium functioning as evaporators in the cooling main operation mode functions as the evaporators in the heating main operation mode as well, and the heat exchangers related to heat medium functioning as condensers in the cooling main operation mode functions as the condensers in the heating main operation mode as well.

11. The air-conditioning apparatus of claim 9, wherein

the third refrigerant flow switching device is opened in the cooling only operation mode and the heating only operation mode, and the third refrigerant flow switching device is closed in the cooling or heating mixed operation mode.

12. The air-conditioning apparatus of claim 9, wherein

when the compressor is stopped, switching states of the second refrigerant flow switching devices is to be the same as the switching state of the cooling only operation mode and the heating only operation mode.

13. The air-conditioning apparatus of claim 9, wherein

the heat exchangers related to heat medium flows the heat source side refrigerant and the heat medium in opposite directions in the heating operation and flows the heat source side refrigerant and the heat medium in the same direction in the cooling operation.

14. The air-conditioning apparatus of claim 9, wherein

the outdoor unit and the heat medium relay unit are interconnected with two pipes.