Cooling/heating switching unit and air conditioner including the same

Patent metadata

Field	Value
Publication number	US-10557648-B2
Application number	US-201715618321-A
Country	US
Kind code	B2
Filing date	Jun 9, 2017
Priority date	Jul 15, 2016
Publication date	Feb 11, 2020
Grant date	Feb 11, 2020

Abstract

A cooling/heating switching unit includes first to third fittings, expansion valves and expansion-valve driving sections, a housing, a heat insulating material, and a refrigerant leak detection sensor. The first and second fittings respectively connect with a high/low-pressure-gas main pipe and a low-pressure-gas main pipe, which are linked to an outdoor unit. The third fitting connects with an indoor-unit connection pipe, which is linked to indoor units. The expansion valve for high/low-pressure-gas pipe, the expansion valve for low-pressure-gas pipe, and expansion-valve driving sections selectively connect the first or second fitting with the third fitting via a refrigerant pipe to control a flow direction of refrigerant. The housing houses the refrigerant pipe. The heat insulating material fills inside of the housing to insulate the refrigerant pipe arranged inside of the housing from heat. The refrigerant leak detection sensor is installed outside of the housing to detect leaked refrigerant.

First claim

The invention claimed is:

1. A cooling/heating switching unit for connection with two or more use-side units and a heat-source-side unit to constitute an air conditioner, the two or more use-side units being independently operable to perform cooling and heating simultaneously, the cooling/heating switching unit comprising:
a first-refrigerant-pipe fitting and a second-refrigerant-pipe fitting that have a first refrigerant pipe and a second refrigerant pipe connected thereto, respectively, wherein the first and second refrigerant pipes are linked to the heat-source-side unit;
a third-refrigerant-pipe fitting that has a third refrigerant pipe connected thereto, wherein the third refrigerant pipe is linked to the use-side unit;
a first expansion valve and a second expansion valve that are configured to control a flow direction of refrigerant from either the first-refrigerant-pipe fitting or the second-refrigerant-pipe fitting to the third-refrigerant-pipe fitting, via a fourth refrigerant pipe, based on a combination of an open state or a closed state of the first expansion valve and the second expansion valve;
a housing that houses at least a part of the fourth refrigerant pipe; and
a refrigerant leak detection sensor that is disposed outside of the housing to detect leaked refrigerant.

2. The cooling/heating switching unit according to claim 1 ,
further comprising additional refrigerant leak detection sensors that are respectively disposed below the first-refrigerant-pipe fitting, the second-refrigerant-pipe fitting, and the third-refrigerant-pipe-fitting.

3. The cooling/heating switching unit according to claim 1 , wherein at least one of the first-refrigerant-pipe fitting, the second-refrigerant-pipe fitting, and the third-refrigerant-pipe fitting are flare connected to the respective first refrigerant pipe, the second refrigerant pipe, and the third refrigerant pipe.

4. The cooling/heating switching unit according to claim 1 , wherein the refrigerant leak detection sensor is disposed below the housing.

5. The cooling/heating switching unit according to claim 1 , wherein
the refrigerant leak detection sensor is connected, via an electric signal line for electrical connection, to a circuit board included in the cooling/heating switching unit, and
the length of the electric signal line is one that allows the refrigerant leak detection sensor to be moved to a point below the housing.

6. The cooling/heating switching unit according to claim 5 , wherein the length of the electric signal line is equal to or longer than the length obtained by adding 50 mm to the distance from the circuit board to a bottom surface of the housing.

7. The cooling/heating switching unit according to claim 1 ,
wherein the refrigerant leak detection sensor is connected, via an electric signal line which is electrically connected to a circuit board included in the cooling/heating switching unit, and
wherein the circuit board includes at least one of a buzzer that emits sound when a leak of refrigerant is detected by the refrigerant leak detection sensor and a light-emitting diode (LED) that emits light when a leak of refrigerant is detected by the refrigerant detection sensor.

8. An air conditioner comprising:
two or more use-side units being independently operable to perform cooling and heating simultaneously;
a heat-source-side unit that are used to form a refrigeration cycle between the heat-source-side unit and the two or more use-side units;
a first-refrigerant-pipe fitting and a second-refrigerant-pipe fitting that have a first refrigerant pipe and a second refrigerant pipe connected thereto, respectively, wherein the first and second refrigerant pipes are linked to the heat-source-side unit;
a third-refrigerant-pipe fitting that has a third refrigerant pipe connected thereto, wherein the third refrigerant pipe is linked to the use-side unit;
a first expansion valve and a second expansion valve that are configured to control a flow direction of refrigerant from either the first-refrigerant-pipe fitting or the second-refrigerant-pipe fitting to the third-refrigerant-pipe fitting, via a fourth refrigerant pipe, based on a combination of an open state or a closed state of the first expansion valve and the second expansion valve;
a housing that houses at least a part of the fourth refrigerant pipe; and a refrigerant leak detection sensor that is disposed outside of the housing to detect leaked refrigerant.

Assignees

• Hitachi Johnson Controls Air Conditioning Inc

Inventors

• Naito Koji
• Fushimi Naoyuki
• Urata Kazumoto
• Yasuda Gen
• Fukuda Kazunori

Classifications

• F25B2313/02732

  using two three-way valves · CPC title

• F25B2313/0231

  with simultaneous cooling and heating · CPC title

• F24F1/32 Primary

  for connecting the separate outdoor units to indoor units · CPC title

• F24F11/36

  to leakage of heat-exchange fluid · CPC title

• F24F2221/54

  Heating and cooling, simultaneously or alternatively · CPC title