Air conditioner

Patent metadata

Field	Value
Publication number	US-10976090-B2
Application number	US-201716338345-A
Country	US
Kind code	B2
Filing date	Sep 29, 2017
Priority date	Sep 30, 2016
Publication date	Apr 13, 2021
Grant date	Apr 13, 2021

Abstract

An air conditioner includes: liquid-side indoor expansion valves corresponding to a liquid side of respective indoor heat exchangers; and gas-side indoor expansion valves corresponding to a gas side of the respective indoor heat exchangers. In a case where both a heating-operation indoor heat exchanger and a heating-stopped indoor heat exchanger are present, the controller of the air conditioner controls the liquid-side indoor expansion valve and the gas-side indoor expansion valve corresponding to the heating-stopped indoor heat exchanger such that an opening degree of the gas-side indoor expansion valve becomes smaller than an opening degree of the liquid-side indoor expansion valve.

First claim

The invention claimed is:

1. An air conditioner comprising:
a refrigerant circuit constituted by connecting a compressor, a plurality of indoor heat exchangers that are parallel with each other, liquid-side indoor expansion valves corresponding to a liquid side of the respective indoor heat exchangers, and an outdoor heat exchanger; and
a controller configured to perform a heating operation in which refrigerant sealed in the refrigerant circuit is circulated in an order of the compressor, the indoor heat exchangers, the liquid-side indoor expansion valves, and the outdoor heat exchanger,
wherein the refrigerant circuit further includes gas-side indoor expansion valves corresponding to a gas side of the respective indoor heat exchangers,
wherein, in a case where the indoor heat exchangers include both a heating-operation indoor heat exchanger that performs the heating operation and a heating-stopped indoor heat exchanger that does not perform the heating operation, the controller is further configured to control the liquid-side indoor expansion valve and the gas-side indoor expansion valve corresponding to the heating-stopped indoor heat exchanger such that an opening degree of the gas-side indoor expansion valve becomes smaller than an opening degree of the liquid-side indoor expansion valve thus causing gas refrigerant to flow from the gas-side indoor expansion valve into the heating-stopped indoor heat exchanger at a lower pressure than gas refrigerant flowing from the gas-side indoor expansion valve into the heating-operation indoor heat exchanger.

2. The air conditioner according to claim 1 , wherein the controller controls the gas-side indoor expansion valve corresponding to the heating-operation indoor heat exchanger such that the opening degree of the gas-side indoor expansion valve becomes fully open.

3. The air conditioner according to claim 1 , wherein the controller controls the gas-side indoor expansion valve corresponding to the heating-stopped indoor heat exchanger such that the opening degree of the gas-side indoor expansion valve becomes 15% or less of a fully open state of the gas-side indoor expansion valve.

4. The air conditioner according to claim 1 , wherein the controller controls the liquid-side indoor expansion valve corresponding to the heating-stopped indoor heat exchanger such that the opening degree of the liquid-side indoor expansion valve becomes fully open.

5. The air conditioner according to claim 1 ,
wherein the refrigerant circuit further includes an outdoor expansion valve between the liquid-side indoor expansion valves and the outdoor heat exchanger, and
wherein the controller controls an opening degree of the outdoor expansion valve such that a temperature of the refrigerant in the heating-stopped indoor heat exchanger becomes lower than or equal to an atmosphere temperature of the heating-stopped indoor heat exchanger.

6. The air conditioner according to claim 1 ,
wherein the refrigerant circuit further includes an outdoor expansion valve between the liquid-side indoor expansion valves and the outdoor heat exchanger, and
wherein the controller controls an opening degree of the outdoor expansion valve such that a temperature of the refrigerant in the heating-stopped indoor heat exchanger becomes higher than or equal to an atmosphere temperature of the heating-stopped indoor heat exchanger.

7. The air conditioner according to claim 1 , wherein the controller performs cooling operation in which the refrigerant sealed in the refrigerant circuit is circulated in an order of the compressor, the outdoor heat exchanger, the liquid-side indoor expansion valves, and the indoor heat exchangers and controls opening degrees of the gas-side indoor expansion valves on the basis of an evaporation temperature of the refrigerant in the indoor heat exchangers.

8. The air conditioner according to claim 1 ,
wherein the respective indoor heat exchangers are provided in indoor units,
wherein the air conditioner is further provided with refrigerant leakage detector that detects leakage of the refrigerant, and
wherein, if the refrigerant leakage detector detects leakage of the refrigerant, the controller controls the liquid-side indoor expansion valves and the gas-side indoor expansion valves such that opening degrees of the liquid-side indoor expansion valves and the gas-side indoor expansion valves become fully closed.

9. The air conditioner according to claim 8 , wherein, before controlling the liquid-side indoor expansion valves and the gas-side indoor expansion valves to be fully closed, the controller stops the compressor.

10. The air conditioner according to claim 8 , wherein the refrigerant circuit further includes pressure adjusting valves that are provided to bypass the respective gas-side indoor expansion valves or the respective liquid-side indoor expansion valves and that open when a pressure of the refrigerant in the indoor heat exchangers increases to a predetermined pressure.

11. The air conditioner according to claim 2 , wherein the controller controls the gas-side indoor expansion valve corresponding to the heating-stopped indoor heat exchanger such that the opening degree of the gas-side indoor expansion valve becomes 15% or less of a fully open state of the gas-side indoor expansion valve.

12. The air conditioner according to claim 2 , wherein the controller controls the liquid-side indoor expansion valve corresponding to the heating-stopped indoor heat exchanger such that the opening degree of the liquid-side indoor expansion valve becomes fully open.

13. The air conditioner according to claim 3 , wherein the controller controls the liquid-side indoor expansion valve corresponding to the heating-stopped indoor heat exchanger such that the opening degree of the liquid-side indoor expansion valve becomes fully open.

14. The air conditioner according to claim 2 ,
wherein the refrigerant circuit further includes an outdoor expansion valve between the liquid-side indoor expansion valves and the outdoor heat exchanger, and
wherein the controller controls an opening degree of the outdoor expansion valve such that a temperature of the refrigerant in the heating-stopped indoor heat exchanger becomes lower than or equal to an atmosphere temperature of the heating-stopped indoor heat exchanger.

15. The air conditioner according to claim 3 ,
wherein the refrigerant circuit further includes an outdoor expansion valve between the liquid-side indoor expansion valves and the outdoor heat exchanger, and
wherein the controller controls an opening degree of the outdoor expansion valve such that a temperature of the refrigerant in the heating-stopped indoor heat exchanger becomes lower than or equal to an atmosphere temperature of the heating-stopped indoor heat exchanger.

16. The air conditioner according to claim 4 ,
wherein the refrigerant circuit further includes an outdoor expansion valve between the liquid-side indoor expansion valves and the outdoor heat exchanger, and
wherein the controller controls an opening degree of the outdoor expansion valve such that a temperature of the refrigerant in the heating-stopped indoor heat exchanger becomes lower than or equal to an atmosphere temperature of the heating-stopped indoor heat exchanger.

17. The air conditioner according to claim 2 ,
wherein the refrigerant circuit further includes an outdoor expansion valve between the liquid-side indoor expansion valves and the outdoor heat exchanger, and
wherein the controller controls an opening degree of the outdoor expansion valve such that a temperature

Assignees

• Daikin Ind Ltd

Inventors

• Yamada Takuro
• Nakagawa Yuusuke
• Honda Masahiro
• Oka Yuusuke

Classifications

• F25B41/39

  Dispositions with two or more expansion means arranged in series, i.e. multi-stage expansion, on a refrigerant line leading to the same evaporator · CPC title

• F25B41/24

  Arrangement of shut-off valves for disconnecting a part of the refrigerant cycle, e.g. an outdoor part · CPC title

• F25B2600/2513

  Expansion valves · CPC title

• F25B2400/13

  Economisers · CPC title

• F25B13/00

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