Refrigeration cycle apparatus

Patent metadata

Field	Value
Publication number	US-11002467-B2
Application number	US-201616331805-A
Country	US
Kind code	B2
Filing date	Oct 25, 2016
Priority date	Oct 25, 2016
Publication date	May 11, 2021
Grant date	May 11, 2021

Abstract

A refrigeration cycle apparatus capable of performing pump down operation while suppressing degradation in performance is provided. The refrigeration cycle apparatus includes an outdoor heat exchanger, a compressor including an inlet side and an outlet side, at least one indoor heat exchanger, a four-way valve, a check valve including an inlet side and an outlet side, a pipe serving as a first flow path connecting the outlet side of the check valve to the inlet side of the compressor, a first on-off valve, and a refrigerant leak detection device. The refrigeration cycle apparatus is configured such that, when a refrigerant leak is detected by the refrigerant leak detection device, pump down operation is performed as refrigerant transfer operation of transferring the refrigerant from the indoor heat exchanger to the outdoor heat exchanger.

First claim

The invention claimed is:

1. A refrigeration cycle apparatus comprising:
an outdoor heat exchanger;
a compressor including an inlet side and an outlet side;
at least one indoor heat exchanger;
a four-way valve;
a check valve including an inlet side and an outlet side;
a flow path extending between and connecting the four-way valve to the inlet side of the check valve;
a pressure sensor connected to the flow path between the four-way valve and the inlet side of the check valve and configured to detect a pressure of the inlet side of the check valve;
a first flow path connecting the outlet side of the check valve to the inlet side of the compressor;
a first on-off valve; and
a refrigerant leak detector configured to detect a refrigerant leak from a refrigerant circuit, the refrigerant circuit being configured to cause refrigerant to circulate through the compressor, the outdoor heat exchanger, the first on-off valve, the at least one indoor heat exchanger, the four-way valve, and the check valve, wherein
the refrigerant circuit is configured, by operation of the four-way valve, such that the refrigerant circulates successively through the compressor, the outdoor heat exchanger, the first on-off valve, the at least one indoor heat exchanger the check valve, and the first flow path in a cooling operation state, and such that the refrigerant circulates successively through the compressor, the at least one indoor heat exchanger, the first on-off valve, the outdoor heat exchanger, the check valve, and the first flow path in a heating operation state,
the refrigeration cycle apparatus is configured such that, when a refrigerant leak is detected by the refrigerant leak detector, refrigerant transfer operation of transferring the refrigerant from the at least one indoor heat exchanger to the outdoor heat exchanger is performed, and
in the refrigerant transfer operation,
when the refrigerant leak is detected by the refrigerant leak detector in the cooling operation state, the compressor is operated with the first on-off valve being closed,
when the refrigerant leak is detected by the refrigerant leak detector in the heating operation state, the compressor is operated with the first on-off valve being closed, after an operation state of the refrigerant circuit is changed from the heating operation state to the cooling operation state, and
when the pressure sensor detects an amount of refrigerant in a flow between the at least one indoor heat exchanger and the check valve via the four-way valve and the flow path equal to or lower than a prescribed amount, the refrigerant transfer operation is stopped.

2. The refrigeration cycle apparatus according to claim 1 , comprising an accumulator installed in the first flow path.

3. The refrigeration cycle apparatus according to claim 1 , comprising a receiver disposed in a second flow path connecting the outdoor heat exchanger to the first on-off valve.

4. The refrigeration cycle apparatus according to claim 1 , wherein the at least one indoor heat exchanger comprises a plurality of indoor heat exchangers and the refrigerant cycle apparatus comprises a plurality of indoor units, wherein each of the plurality of indoor units has one of the plurality indoor heat exchangers respectively.

5. The refrigeration cycle apparatus according to claim 1 , comprising a receiver disposed in another flow path connecting the first on-off valve to the at least one indoor heat exchanger.

6. The refrigeration cycle apparatus according to claim 1 , comprising a second on-off valve disposed in another flow path connecting the first on-off valve to the at least one indoor heat exchanger, wherein
the refrigeration cycle apparatus is configured to close the second on-off valve when a power failure occurs during the refrigerant transfer operation.

Assignees

• Mitsubishi Electric Corp

Inventors

• Wada Makoto
• Matsuda Takuya
• Motomura Yuji
• Ishimura Katsuhiro

Classifications

• F25B49/02 Primary

  for compression type machines, plants or systems · CPC title

• F25B2313/02741

  using one four-way valve · CPC title

• F25B2400/19

  Pumping down refrigerant from one part of the cycle to another part of the cycle, e.g. when the cycle is changed from cooling to heating, or before a defrost cycle is started · CPC title

• F25B43/00

  Arrangements for separating or purifying gases or liquids (in analysers or rectifiers F25B33/00); Arrangements for vaporising the residuum of liquid refrigerant, e.g. by heat (F25B40/00 takes precedence) · CPC title

• F25B2700/1933

  Suction pressures · CPC title