Refrigeration cycle apparatus

Patent metadata

Field	Value
Publication number	US-9631847-B2
Application number	US-201114345300-A
Country	US
Kind code	B2
Filing date	Oct 4, 2011
Priority date	Oct 4, 2011
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

The volume ratio of a hot-water-supply-side liquid extension pipe to a water heat exchanger is set to be equal to or more than the minimum volume ratio, which is the volume ratio of the hot-water-supply-side liquid extension pipe to the water heat exchanger when the required refrigerant amount during a cooling and hot water supply simultaneous operation in which an indoor-side heat exchanger serves as an evaporator, the water heat exchanger serves as a condenser, cooling energy is supplied from the indoor-side heat exchanger, and heating energy is supplied from the water heat exchanger is equal to the required refrigerant amount during a heating operation in which a heat-source-side heat exchanger serves as an evaporator, the indoor-side heat exchanger serves as a condenser, and heating energy is supplied from the indoor-side heat exchanger.

First claim

The invention claimed is:

1. A refrigeration cycle apparatus comprising:
a heat source unit including a compressor, a heat-source-side heat exchanger, an expansion valve, and a liquid reservoir;
an indoor unit including an indoor-side heat exchanger; and
a hot water supply unit including a water heat exchanger,
the heat source unit and the indoor unit being connected together by indoor-side liquid extension pipes including an indoor-side liquid extension pipe and an indoor-side gas extension pipe, and the heat source unit and the hot water supply unit being connected together by hot-water-supply-side liquid extension pipes including a hot-water-supply-side liquid extension pipe and a hot-water-supply-side gas extension pipe, wherein
the refrigeration cycle apparatus performs a cooling and hot water supply simultaneous operation in which the indoor-side heat exchanger serves as an evaporator and the water heat exchanger serves as a condenser, a heating operation in which the heat-source-side heat exchanger serves as an evaporator and the indoor-side heat exchanger serves as a condenser, and a cooling operation in which the heat-source-side heat exchanger serves as a condenser and the indoor-side heat exchanger serves as an evaporator,
a capacity of the heat-source-side heat exchanger is larger than a capacity of the indoor-side heat exchanger and the water heat exchanger, and
the hot-water-supply side liquid extension pipe and the water heat exchanger have a volume ratio of the hot-water-supply-side liquid extension pipe to the water heat exchanger is equal to or more than a volume ratio of the hot-water-supply-side liquid extension pipe to the water heat exchanger when a required refrigerant amount during the cooling and hot water supply simultaneous operation is equal to a required refrigerant amount during the heating operation.

2. The refrigeration cycle apparatus of claim 1 ,
wherein the volume ratio of the hot-water-supply-side liquid extension pipe to the water heat exchanger is set based on at least one of a length of the hot-water-supply-side extension pipes and an inner diameter of the hot-water-supply-side liquid extension pipe.

3. The refrigeration cycle apparatus of claim 1 ,
wherein an additional filling refrigerant amount to the refrigeration cycle apparatus is set based not on the length of the hot-water-supply-side extension pipes but on the length of the indoor-side extension pipes.

4. The refrigeration cycle apparatus of claim 1 ,
wherein the volume ratio of the hot-water-supply-side liquid extension pipe to the indoor-side liquid extension pipe is,
in a case where a required refrigerant amount during a cooling operation in which the indoor-side heat exchanger serves as an evaporator, the heat-source-side heat exchanger serves as a condenser, and cooling energy is supplied from the indoor-side heat exchanger is greater than the required refrigerant amount during the heating operation, set to be equal to or less than an upper limit volume ratio, which is the volume ratio of the hot-water-supply-side liquid extension pipe to the indoor-side liquid extension pipe when a required refrigerant amount during a hot water supply operation in which the heat-source-side heat exchanger serves as an evaporator, the water heat exchanger serves as a condenser, and heating energy is supplied from the water heat exchanger is equal to the required refrigerant amount during the cooling operation, and
in a case where the required refrigerant amount during the heating operation is greater than the required refrigerant amount during the cooling operation, set to be equal to or less than an upper limit volume ratio, which is the volume ratio of the hot-water-supply-side liquid extension pipe to the indoor-side liquid extension pipe when the required refrigerant amount during the cooling and hot water supply simultaneous operation is equal to the required refrigerant amount during the heating operation.

5. The refrigeration cycle apparatus of claim 4 ,
wherein in a case where the required refrigerant amount during the heating operation is greater than the required refrigerant amount during the cooling operation,
the volume ratio of the hot-water-supply-side liquid extension pipe to the indoor-side liquid extension pipe is
set to be equal to or more than a lower limit volume ratio, which is the volume ratio of the hot-water-supply-side liquid extension pipe to the indoor-side liquid extension pipe when a difference in required refrigerant amount between the heating operation and the hot water supply operation is equal to the amount of refrigerant in the liquid reservoir in a state in which an effective internal volume of the liquid reservoir is filled with liquid refrigerant.

6. The refrigeration cycle apparatus of claim 4 ,
wherein the heat source unit includes:
a high-pressure sensor that detects a high pressure of refrigerant at a position that falls within a range from the compressor to the expansion valve;
a heat-source-side heat exchanger liquid-side temperature sensor that detects a temperature of refrigerant on a liquid side of the heat-source-side heat exchanger; and
a controller including a degree-of-subcooling controlling unit that controls an opening degree of the expansion valve so that the degree of subcooling of the refrigerant on the liquid side of the heat-source-side heat exchanger during the cooling operation has a predetermined value or below.

7. The refrigeration cycle apparatus of claim 6 , wherein the predetermined value is a predetermined value that prevents a liquid refrigerant from flowing from the liquid reservoir to the compressor of the heat-source-side unit.

8. The refrigeration cycle apparatus of claim 4 ,
wherein a concurrent condensing operation in which the indoor-side heat exchanger serves as an evaporator, the water heat exchanger serves as a condenser, and the heat-source-side heat exchanger serves as a condenser is possible, and
wherein a concurrent condensing operation execution unit that executes the concurrent condensing operation before switching is performed from the cooling operation to the cooling and hot water supply simultaneous operation is provided.

9. The refrigeration cycle apparatus of claim 8 ,
wherein the hot water supply unit includes:
a water heat exchanger outlet water temperature sensor that detects an outlet water temperature at the water heat exchanger; and
a water heat exchanger liquid-side temperature sensor that detects a temperature of refrigerant on a liquid side of the water heat exchanger, and
wherein the concurrent condensing operation execution unit terminates the concurrent condensing operation when the temperature of the refrigerant on the liquid side of the water heat exchanger becomes lower than the outlet water temperature by a predetermined value or more in the concurrent condensing operation.

10. The refrigeration cycle apparatus of claim 1 ,
wherein the heat source unit includes
a low-pressure bypass pipe for connecting a connection point A at a position that falls within a range between the compressor and a gas side of the heat-source-side heat exchanger, and a connection point B at a position that falls within a range between the indoor-side heat exchanger and the expansion valve, and
wherein a low-pressure equalization solenoid valve and a check valve are installed at the low-pressure bypass pipe so that refrigerant flows from the connection point A toward the connection point B.

11. The refrigeration cycle apparatus of claim 1 ,
wherein the hot water supply unit includes
a subcooling heat exchanger for cooling refrigerant serving as subcooled liquid on a liquid side of the water heat excha

Assignees

• Tamaki Shogo
• Saito Makoto
• Oya Ryo
• Mitsubishi Electric Corp

Inventors

• Tamaki Shogo
• Saito Makoto
• Oya Ryo

Classifications

• F25B2700/21163

  of the refrigerant at the outlet of the condenser · CPC title

• F25B2700/21161

  of the fluid heated by the condenser · CPC title

• F25B2700/21152

  at the discharge side of the compressor · CPC title

• F25B2700/1931

  Discharge pressures · CPC title

• F25B2600/0261

  external to the compressor · CPC title