Refrigeration cycle device

Patent metadata

Field	Value
Publication number	US-12140353-B2
Application number	US-202217576030-A
Country	US
Kind code	B2
Filing date	Jan 14, 2022
Priority date	Jul 22, 2019
Publication date	Nov 12, 2024
Grant date	Nov 12, 2024

Abstract

A refrigeration cycle device includes a compressor configured to compress and discharge a refrigerant containing oil, a refrigerant radiator configured to heat the ventilation air using the refrigerant discharged from the compressor as a heat source during a room interior heating, a refrigerant decompression unit configured to decompress the refrigerant having passed through the refrigerant radiator, an evaporator configured to evaporate the refrigerant and to function as a heat absorber during the room interior heating; and a controller configured to control the refrigerant decompression unit and to perform a fluctuation operation at least during the room interior heating. In the fluctuation operation, a throttle opening degree of the refrigerant decompression unit is changed such that a refrigerant state on a refrigerant outlet side of the evaporator is alternately changed to a superheated state having a superheat degree and a wet state containing the wet vapor.

First claim

What is claimed is:

1. A refrigeration cycle device capable of performing a room interior heating in which ventilation air to be blown into a space to be air conditioned is heated, the refrigeration cycle device comprising:
a compressor configured to compress and discharge a refrigerant containing oil;
a refrigerant radiator configured to heat the ventilation air using the refrigerant discharged from the compressor as a heat source during the room interior heating;
a refrigerant decompression unit configured to decompress the refrigerant having passed through the refrigerant radiator;
an evaporator configured to evaporate the refrigerant and to function as a heat absorber during the room interior heating; and
a controller configured to control a throttle opening degree of the refrigerant decompression unit, wherein
the controller is configured to perform, at least during the room interior heating, a fluctuation operation in which the throttle opening degree of the refrigerant decompression unit is changed and a refrigerant state on a refrigerant outlet side of the evaporator is alternately changed to a superheated state having a superheat degree and a wet state containing wet vapor.

2. The refrigeration cycle device according to claim 1 , wherein the evaporator is a heat exchanger that exchanges heat between the refrigerant decompressed in the refrigerant decompression unit and a heat medium circulating in a heat medium circuit.

3. The refrigeration cycle device according to claim 1 , wherein
the controller is configured to perform the fluctuation operation to have;
(i) a first state in which the throttle opening degree of the refrigerant decompression unit is reduced until the superheat degree of the refrigerant on the refrigerant outlet side of the evaporator reaches a threshold temperature;
(ii) a second state in which the throttle opening degree of the refrigerant decompression unit is increased until the throttle opening degree of the refrigerant decompression unit reaches a reference opening degree at which the refrigerant state becomes the wet state, in response to that the superheat degree of the refrigerant on the refrigerant outlet side of the evaporator reaches the threshold temperature in the first state; and
(iii) a third state in which the throttle opening degree of the refrigerant decompression unit is reduced again until the superheat degree of the refrigerant on the refrigerant outlet side of the evaporator reaches the threshold temperature, in response to that the throttle opening degree of the refrigerant decompression unit reaches the reference opening degree in the second state.

4. The refrigeration cycle device according to claim 1 , wherein the controller is configured to perform the fluctuation operation to have:
(i) a first state in which the throttle opening degree of the refrigerant decompression unit is reduced until the throttle opening degree of the refrigerant decompression unit reaches a first reference opening degree at which the superheat degree of the refrigerant on the refrigerant outlet side of the evaporator becomes a value equal to or higher than a predetermined threshold temperature;
(ii) a second state in which the throttle opening degree of the refrigerant decompression unit is increased until the throttle opening degree of the refrigerant decompression unit reaches a second reference opening degree at which the refrigerant state becomes the wet state, in response to that the throttle opening degree of the refrigerant decompression unit reaches the first reference opening degree; and
(iii) a third state in which the throttle opening degree of the refrigerant decompression unit is reduced again until the throttle opening degree of the refrigerant decompression unit reaches the first reference opening degree, in response to that the throttle opening degree of the refrigerant decompression unit reaches the second reference opening degree.

5. The refrigeration cycle device according to claim 1 , wherein
the controller controls the refrigerant decompression unit to perform the fluctuation operation in which a variation in the throttle opening degree per unit time is greater when the throttle opening degree of the refrigerant decompression unit is increased, than that when the throttle opening degree of the refrigerant decompression unit is reduced.

6. The refrigeration cycle device according to claim 1 , wherein
the refrigerant radiator includes a condensing portion in which the refrigerant is condensed, and a liquid receiving portion in which the refrigerant having passed through the condensing portion is cooled and condensed into a vapor-phase refrigerant and a liquid-phase refrigerant to store therein a surplus liquid-phase refrigerant in the cycle.

7. The refrigeration cycle device according to claim 6 , wherein the refrigerant radiator further includes a subcooling portion that releases heat from the refrigerant having passed through the liquid receiving portion.

8. A refrigeration cycle device capable of performing a room interior heating in which ventilation air to be blown into a space to be air conditioned is heated, a device cooling in which a heat generating device is cooled, and a room interior cooling in which the ventilation air is cooled, the refrigeration cycle device comprising:
a compressor configured to compress and discharge a refrigerant containing oil;
a refrigerant radiator configured to heat the ventilation air to be blown into the space to be air conditioned using the refrigerant discharged from the compressor as a heat source during the room interior heating;
a refrigerant decompression valve configured to decompress the refrigerant having passed through the refrigerant radiator;
a parallel decompression valve disposed in parallel with the refrigerant decompression valve on a downstream side of the refrigerant radiator in a refrigerant flow;
a heat exchanger disposed to exchange heat between the refrigerant decompressed in the refrigerant decompression valve and a thermal medium of a thermal medium circuit, the heat exchanger being configured to cool the heat generating device via the thermal medium by using latent heat of evaporation of the refrigerant decompressed in the refrigerant decompression valve during the device cooling, and to function as a heat absorber during the room interior heating;
an air-conditioning cooler configured to cool the ventilation air using the latent heat of evaporation of the refrigerant decompressed in the parallel decompression valve; and
a controller configured to control a throttle opening degree of the refrigerant decompression valve and a throttle opening degree of the parallel decompression valve, wherein
the controller is configured to perform, at least during the room interior heating, a fluctuation operation in which the throttle opening degree of the refrigerant decompression valve is changed and a refrigerant state on a refrigerant outlet side of the device cooler heat exchanger is alternately changed to a superheated state having a superheat degree and a wet state containing wet vapor.

9. The refrigeration cycle device according to claim 8 , further comprising
a pressure regulation valve disposed on a downstream side of the air-conditioning cooler in a refrigerant flow, and configured to maintain a refrigerant pressure on a refrigerant outlet side of the air-conditioning cooler higher than a refrigerant pressure on the refrigerant outlet side of the heat exchanger.

10. The refrigeration cycle device according to claim 8 , wherein
the controller is configured to perform the fluctuation operation to have:
(i) a first state in which the throttle opening degree of the refrigerant decompressio

Assignees

• Denso Corp

Inventors

• Inagaki Kouji
• Katou Daiki
• Kawano Hiroaki
• Katoh Yoshiki
• Makimoto Naoya

Classifications

• F25B5/02

  arranged in parallel · CPC title

• F24D2200/31

  Air conditioning systems · CPC title

• F24D5/02

  operating with discharge of hot air into the space or area to be heated · CPC title

• F25B2327/001

  Mechanical Engineering · mapped topic

• F25B41/30

  Expansion means; Dispositions thereof · CPC title