Air conditioner

Patent metadata

Field	Value
Publication number	US-10533764-B2
Application number	US-201916385819-A
Country	US
Kind code	B2
Filing date	Apr 16, 2019
Priority date	Oct 28, 2016
Publication date	Jan 14, 2020
Grant date	Jan 14, 2020

Abstract

When refrigerant leakage occurs, a controller in an air conditioner performs first shutoff control to open a liquid relay shutoff valve and close an indoor expansion valve and a gas relay shutoff valve on the basis of information from a refrigerant leakage detector.

First claim

The invention claimed is:

1. An air conditioner comprising:
an outdoor unit including a compressor;
a plurality of indoor units ( 3 a , 3 b , 3 c , 3 d ), each including an indoor expansion valve and an indoor heat exchanger;
a liquid-refrigerant connection pipe and a gas-refrigerant connection pipe that connect the outdoor unit and the indoor units to each other;
at least one relay unit disposed in the liquid-refrigerant connection pipe and the gas-refrigerant connection pipe, the at least one relay unit including a liquid relay shutoff valve in a liquid connection pipe connected to the liquid-refrigerant connection pipe and a gas relay shutoff valve in a gas connection pipe connected to the gas-refrigerant connection pipe, the at least one relay unit being configured to individually switch the plurality of indoor heat exchangers so that each of the plurality of indoor heat exchangers functions as an evaporator for refrigerant or a radiator for the refrigerant;
a refrigerant leakage detector for detecting leakage of the refrigerant; and
a controller that controls components of the outdoor unit, the indoor units, and the relay unit, wherein
when leakage of the refrigerant occurs, the controller is configured to perform first shutoff control to open the liquid relay shutoff valve and close at least one of the indoor expansion valves and the gas relay shutoff valve on the basis of information from the refrigerant leakage detector.

2. The air conditioner according to claim 1 , wherein
the liquid relay shutoff valve comprises an electric expansion valve, and
the controller slightly opens the liquid relay shutoff valve in the first shutoff control.

3. The air conditioner according to claim 1 , wherein
when it is determined that the leakage of the refrigerant continues even after the first shutoff control is performed, the controller performs second shutoff control to close the liquid relay shutoff valve with the at least one of the indoor expansion valves closed.

4. The air conditioner according to claim 3 , wherein
each of the indoor units further includes a temperature sensor that detects a temperature of the refrigerant around the indoor heat exchanger, and
the controller determines whether the leakage of the refrigerant continues even after the first shutoff control is performed, on the basis of the temperatures of the refrigerant detected by the temperature sensors during the first shutoff control.

5. The air conditioner according to claim 3 , wherein
the controller opens the gas relay shutoff valve in the second shutoff control.

6. The air conditioner according to claim 5 , wherein
the gas relay shutoff valve comprises an electric expansion valve, and
the controller slightly opens the gas relay shutoff valve in the second shutoff control.

7. The air conditioner according to claim 2 , wherein
when it is determined that the leakage of the refrigerant continues even after the first shutoff control is performed, the controller performs second shutoff control to close the liquid relay shutoff valve with the at least one of the indoor expansion valves closed.

8. The air conditioner according to claim 4 , wherein
the controller opens the gas relay shutoff valve in the second shutoff control.

Assignees

• Daikin Ind Ltd

Inventors

• Yamada Takuro
• Nakagawa Yuusuke
• Oka Yuusuke

Classifications

• F25B2500/22

  Preventing, detecting or repairing leaks of refrigeration fluids · 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

• F25B2313/02732

  using two three-way valves · CPC title

• F24F11/88

  Electrical aspects, e.g. circuits · CPC title

• F25B2600/2507

  Flow-diverting valves · CPC title