| CPC F25B 49/02 (2013.01) [F25B 13/00 (2013.01); F25B 39/00 (2013.01); F25B 41/31 (2021.01); F25B 41/40 (2021.01); F25B 2313/02741 (2013.01); F25B 2600/2513 (2013.01); F25B 2700/02 (2013.01); F25B 2700/1931 (2013.01); F25B 2700/2103 (2013.01); F25B 2700/2104 (2013.01); F25B 2700/2106 (2013.01)] | 13 Claims |
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1. A multi-air conditioner for heating and cooling, comprising:
at least one indoor unit for both cooling and heating comprising an indoor heat exchanger;
an outdoor unit for both cooling and heating comprising a compressor, a plurality of outdoor heat exchangers, and a four-way valve disposed on a discharge side of the compressor to switch a flow of a refrigerant; and
a distributor disposed between the outdoor unit and the at least one indoor unit, that distributes the refrigerant, wherein the plurality of outdoor heat exchangers comprises:
a first heat exchanger, a first end of which is connected to the four-way valve, and a second end of which is connected to the distributor;
a second heat exchanger disposed under the first heat exchanger, a first end of which is configured to be coupled to or decoupled from the second end of the first heat exchanger, and a second end of which is connected to the distributor;
a third heat exchanger disposed under the second heat exchanger, a first end of which is connected to the discharge side of the compressor, and a second end of which is connected to the at least one indoor unit;
a first connecting pipeline that connects the second end of the first heat exchanger and the first end of the second heat exchanger in series;
a first connecting valve disposed on the first connecting pipeline, that switches on or off a mechanical connection between the first heat exchanger and the second heat exchanger; and
a first expansion valve, a second expansion valve, and a third expansion valve on the second end of the first heat exchanger, the second heat exchanger, and the third heat exchanger, respectively, wherein the multi-air conditioner selects a specific mode of operation by putting together a mode of operation selected by a user and current status information, wherein when the mode of operation selected by the user is a heating operation, if an outdoor temperature is at or below a first temperature, an outdoor humidity is above a predetermined range, and a load of the at least one indoor unit is at or above a predetermined value, an anti-frost mode is enabled in which frost due to condensate dropping from the first and second heat exchangers is prevented from forming by controlling the third expansion valve to direct the refrigerant discharged to the discharge side of the compressor to the third heat exchanger, wherein the outdoor unit further comprises:
a first sub pipeline that connects the first end of the third heat exchanger and the second end of the first heat exchanger;
a second sub pipeline that connects the first end of the third heat exchanger and the second end of the second heat exchanger;
a first sub valve disposed on the first sub pipeline, that turns on or off a flow of the refrigerant to the first sub pipeline; and
a second sub valve disposed on the second sub pipeline, that turns on or off a flow of the refrigerant to the second sub pipeline, wherein when the multi-air conditioner is in a defrosting operation, a defrost continuous heating mode is enabled in which a lower portion defrost mode and an upper portion defrost mode alternate, wherein the lower portion defrost mode comprises defrosting the second heat exchanger by running the refrigerant discharged from the compressor to the second heat exchanger and the third heat exchanger while the refrigerant evaporates in the first heat exchanger, wherein the upper portion defrost mode comprises defrosting the first heat exchanger by running the refrigerant discharged from the compressor to the first heat exchanger and the third heat exchanger while the refrigerant evaporates in the second heat exchanger, wherein when the multi-air conditioner is in the defrost continuous heating mode, the third expansion valve is fully opened, and wherein when the multi-air conditioner is in the anti-frost mode, the third expansion valve is opened to a minimum degree.
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