Manufacturing method of transition critical refrigerating cycle device

Abstract

An object of the present invention is to provide a manufacturing method of a transition critical refrigerating cycle device in which a gas cooler and a sub-cooler constitute one heat exchanger so as to most efficiently cool a refrigerant in the device. During manufacturing of the transition critical refrigerating cycle device constituted by successively connecting a compressor, the gas cooler, a capillary tube and an evaporator and having a supercritical pressure on a high-pressure side of the device, the sub-cooler which cools an intermediate-pressure refrigerant of the compressor is disposed, the gas cooler and the sub-cooler are integrated to constitute a heat exchanger, and a ratio of the number of refrigerant pipes of the sub-cooler to the number of refrigerant pipes of the whole heat exchanger is set to 20% or more and 30% or less.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a low-temperature showcase according to an embodiment to which the present invention is applied;

FIG. 2 is a perspective view of a cooling unit of the low-temperature showcase of FIG. 1 according to an embodiment of a transition critical refrigerating cycle device;

FIG. 3 is a perspective view of a lift mechanism which pushes up the cooling unit of FIG. 2;

FIG. 4 is a refrigerant circuit diagram of the cooling unit shown in FIG. 2;

FIG. 5 is a side view of a heat exchanger constituted by integrating a sub-cooler and a gas cooler;

FIG. 6 is a graph showing an outlet temperature of the sub-cooler in a case where the number of refrigerant pipes of the sub-cooler is changed in the heat exchanger of FIG. 5;

FIG. 7 is a side view of another embodiment of the heat exchanger shown in FIG. 5; and

FIG. 8 is a side view of still another embodiment of the heat exchanger shown in FIG. 5.

Claims

1. A manufacturing method of a transition critical refrigerating cycle device constituted by successively connecting a compressor, a gas cooler, a throttling device and an evaporator and having a supercritical pressure on a high-pressure side of the device, the method comprising: disposing s sub-cooler which cools an intermediate-pressure refrigerant of the compressor;integrating the gas cooler and the sub-cooler to constitute a heat exchanger; andsetting a ratio of the number of refrigerant pipes of the sub-cooler to the number of refrigerant pipes of the whole heat exchanger to 20% or more and 30% or less.

2. The manufacturing method of the transition critical refrigerating cycle device according to claim 1, wherein the ratio of the number of the refrigerant pipes of the sub-cooler to the number of the refrigerant pipes of the whole heat exchanger is set to 23% or more and 28% or less.

3. The manufacturing method of the transition critical refrigerating cycle device according to claim 2, wherein the compressor includes low-stage compression means and high-stage compression means; the refrigerant discharged from the low-stage compression means enters the sub-cooler;the refrigerant cooled by the sub-cooler is sucked into the high-end compression means; andthe refrigerant discharged from the high-stage compression means enters the gas cooler.

4. The manufacturing method of the transition critical refrigerating cycle device according to claim 3, wherein carbon dioxide is used as the refrigerant.

5. The manufacturing method of the transition critical refrigerating cycle device according to claim 1, wherein the compressor includes low-stage compression means and high-stage compression means; the refrigerant discharged from the low-stage compression means enters the sub-cooler;the refrigerant cooled by the sub-cooler is sucked into the high-end compression means; andthe refrigerant discharged from the high-stage compression means enters the gas cooler.

6. The manufacturing method of the transition critical refrigerating cycle device according to claim 5, wherein carbon dioxide is used as the refrigerant.

7. The manufacturing method of the transition critical refrigerating cycle device according to claim 1, wherein carbon dioxide is used as the refrigerant.

8. The manufacturing method of the transition critical refrigerating cycle device according to claim 2, wherein carbon dioxide is used as the refrigerant.