Refrigerant cycle apparatus

Patent metadata

Field	Value
Publication number	US-2022065506-A1
Application number	US-202017427306-A
Country	US
Kind code	A1
Filing date	Jan 27, 2020
Priority date	Jan 31, 2019
Publication date	Mar 3, 2022
Grant date	—

Abstract

An air conditioner includes a use-side unit, a heat source-side unit, refrigerant connection pipes, cutoff valve provided in the refrigerant connection pipes, a refrigerant leakage detector, and a controller control. When the refrigerant leakage detector detects a refrigerant leakage, the controller performs pressure reduction control to lower the pressure of the refrigerant in the use-side unit, and thereafter puts the cutoff valves into a cutoff state.

First claim

1 . A refrigerant cycle apparatus comprising:
a use-side unit; a heat source-side unit including a heat source-side expansion valve; refrigerant connection pipes connecting the use-side unit to the heat source-side unit; a cutoff unit provided in the refrigerant connection pipes and configured to cut off inflow of a refrigerant into the use-side unit; a refrigerant leakage detector configured to detect leakage of the refrigerant from the use-side unit; and a controller configured to perform pressure reduction control, when the refrigerant leakage detector detects the leakage of the refrigerant, to lower pressure of the refrigerant in the use-side unit and thereafter put the cutoff unit into a cutoff state, wherein in the pressure reduction control, the controller lowers the pressure of the refrigerant flowing from the heat source-side unit to the use-side unit by reducing an opening degree of the heat source-side expansion valve, and after the pressure reduction control lowers the pressure of the refrigerant in the use-side unit and reduces a pressure difference between an installation space of the use-side unit and the pressure of the refrigerant in the use-side unit, the controller puts the cutoff unit into a cutoff state.

2 . The refrigerant cycle apparatus according to claim 1 , wherein
the refrigerant connection pipes include a high pressure-side first refrigerant connection pipe and a low pressure-side second refrigerant connection pipe, the cutoff unit includes include a first cutoff valve provided in the first refrigerant connection pipe and a second cutoff valve provided in the second refrigerant connection pipe.

3 . The refrigerant cycle apparatus according to claim 1 , wherein
when the refrigerant leakage detector detects the leakage of the refrigerant, the controller performs the pressure reduction control to lower the pressure of the refrigerant in the use-side unit, and thereafter puts the cutoff unit into the cutoff state when a predetermined time elapses.

4 . The refrigerant cycle apparatus according to claim 1 , wherein
when the refrigerant leakage detector detects the leakage of the refrigerant, the controller performs the pressure reduction control to lower the pressure of the refrigerant in the use-side unit, and thereafter puts the cutoff unit into the cutoff state when the pressure of the refrigerant or a temperature of the refrigerant in the use-side unit satisfies a predetermined condition.

5 . The refrigerant cycle apparatus according to claim 1 , wherein
in the pressure reduction control to lower the pressure of the refrigerant in the use-side unit, the controller performs control to prevent the pressure of the refrigerant in the use-side unit from becoming lower than atmospheric pressure.

6 . The refrigerant cycle apparatus according to claim 1 , wherein
as the refrigerant, a single refrigerant of R32, R1234yf, R1234ze, or R744, or a mixed refrigerant including the refrigerant is used.

7 . A refrigerant cycle apparatus comprising:
a use-side unit; a heat source-side unit; refrigerant connection pipes connecting the use-side unit to the heat source-side unit; a cutoff unit provided in the refrigerant connection pipes and configured to cut off inflow of a refrigerant into the use-side unit; a refrigerant leakage detector configured to detect leakage of the refrigerant from the use-side unit; and a controller configured to perform pressure reduction control, when the refrigerant leakage detector detects the leakage of the refrigerant, to lower pressure of the refrigerant in the use-side unit and thereafter put the cutoff unit into a cutoff state, wherein the heat source-side unit includes: a compressor; a heat source-side heat exchanger configured to radiate heat from the refrigerant discharged from the compressor; and a bypass route configured to return a part of the refrigerant discharged from the compressor and from which heat is radiated by the heat source-side heat exchanger to the compressor without going through the use-side unit, in the pressure reduction control, the controller reduces an amount of the refrigerant flowing from the heat source-side unit to the use-side unit by returning the refrigerant to the compressor by using the bypass route.

8 . (canceled)

9 . The refrigerant cycle apparatus according to claim 2 , wherein
when the refrigerant leakage detector detects the leakage of the refrigerant, the controller performs the pressure reduction control to lower the pressure of the refrigerant in the use-side unit, and thereafter puts the cutoff unit into the cutoff state when a predetermined time elapses.

10 . The refrigerant cycle apparatus according to claim 2 , wherein
when the refrigerant leakage detector detects the leakage of the refrigerant, the controller performs the pressure reduction control to lower the pressure of the refrigerant in the use-side unit, and thereafter puts the cutoff unit into the cutoff state when the pressure of the refrigerant or a temperature of the refrigerant in the use-side unit satisfies a predetermined condition.

11 . The refrigerant cycle apparatus according to claim 3 , wherein
when the refrigerant leakage detector detects the leakage of the refrigerant, the controller performs the pressure reduction control to lower the pressure of the refrigerant in the use-side unit, and thereafter puts the cutoff unit into the cutoff state when the pressure of the refrigerant or a temperature of the refrigerant in the use-side unit satisfies a predetermined condition.

12 . The refrigerant cycle apparatus according to claim 2 , wherein
in the pressure reduction control to lower the pressure of the refrigerant in the use-side unit, the controller performs control to prevent the pressure of the refrigerant in the use-side unit from becoming lower than atmospheric pressure.

13 . The refrigerant cycle apparatus according to claim 3 , wherein
in the pressure reduction control to lower the pressure of the refrigerant in the use-side unit, the controller performs control to prevent the pressure of the refrigerant in the use-side unit from becoming lower than atmospheric pressure.

14 . The refrigerant cycle apparatus according to claim 4 , wherein
in the pressure reduction control to lower the pressure of the refrigerant in the use-side unit, the controller performs control to prevent the pressure of the refrigerant in the use-side unit from becoming lower than atmospheric pressure.

15 . The refrigerant cycle apparatus according to claim 2 , wherein
as the refrigerant, a single refrigerant of R32, R1234yf, R1234ze, or R744, or a mixed refrigerant including the refrigerant is used.

16 . The refrigerant cycle apparatus according to claim 3 , wherein
as the refrigerant, a single refrigerant of R32, R1234yf, R1234ze, or R744, or a mixed refrigerant including the refrigerant is used.

17 . The refrigerant cycle apparatus according to claim 4 , wherein
as the refrigerant, a single refrigerant of R32, R1234yf, R1234ze, or R744, or a mixed refrigerant including the refrigerant is used.

18 . The refrigerant cycle apparatus according to claim 5 , wherein
as the refrigerant, a single refrigerant of R32, R1234yf, R1234ze, or R744, or a mixed refrigerant including the refrigerant is used.

Assignees

• Daikin Ind Ltd

Inventors

• Yajima Ryuuzaburou

Classifications

• F25B2313/0253

  in parallel arrangements · CPC title

• F25B41/42

  Arrangements for diverging or converging flows, e.g. branch lines or junctions · CPC title

• F25B13/00

  Compression machines, plants or systems, with reversible cycle (defrosting cycles F25B47/02) · CPC title

• F25B2700/1931

  Discharge pressures · CPC title

• F25B2400/0401

  for compressors · CPC title