US 12,326,270 B2
Air conditioner
Hiroyuki Nagai, Shizuoka (JP); Ken Miura, Shizuoka (JP); and Irvan Brata Tarigan, Shizuoka (JP)
Assigned to CARRIER JAPAN CORPORATION, Tokyo (JP)
Appl. No. 18/245,090
Filed by CARRIER JAPAN CORPORATION, Tokyo (JP)
PCT Filed Aug. 25, 2021, PCT No. PCT/JP2021/031243
§ 371(c)(1), (2) Date Mar. 13, 2023,
PCT Pub. No. WO2022/054584, PCT Pub. Date Mar. 17, 2022.
Claims priority of application No. 2020-154116 (JP), filed on Sep. 14, 2020.
Prior Publication US 2023/0358432 A1, Nov. 9, 2023
Int. Cl. F24F 11/84 (2018.01); F24F 1/0059 (2019.01)
CPC F24F 11/84 (2018.01) [F24F 1/0059 (2013.01)] 2 Claims
OG exemplary drawing
 
1. An air-conditioner comprising:
a controller;
a refrigerant circuit configured by connecting, via connecting piping:
an outdoor unit including a compressor,
an outdoor heat exchanger,
an accumulator, and
a supercooling heat exchanger, and
a plurality of indoor units each including an indoor heat exchanger and an indoor expansion valve configured to adjust an amount of a refrigerant flowing into the indoor heat exchanger, wherein:
the accumulator is connected to a suction side of the compressor, and a bottom portion of the accumulator is connected to a suction side of the compressor via return bypass piping that has a valve;
the outdoor heat exchanger and the supercooling heat exchanger are sequentially connected to a discharge side of the compressor, a cooling source of the supercooling heat exchanger is a supercooling bypass circuit provided with a supercooling expansion valve, the supercooling bypass circuit is configured to expand the refrigerant on a downstream side of the outdoor heat exchanger by the supercooling expansion valve, lead the refrigerant to the supercooling heat exchanger, and then lead the refrigerant to the accumulator;
the controller is configured to determine whether the amount of the refrigerant in the refrigerant circuit is excessive during a heating operation as a determination index in response to at least one of the following cases:
an opening degree of the indoor expansion valve being larger than a predetermined opening degree, and
a difference between an indoor supercooling degree detected and a target indoor supercooling degree exceeding a predetermined value; and
the controller is configured to fully close the valve of the return bypass piping and gradually increase opening degree of the supercooling expansion valve of the supercooling bypass circuit from a fully closed state in response to determining the amount of the refrigerant in the refrigerant circuit is excessive.