JPS6124950A - Two-element refrigerator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a binary refrigeration system, and particularly to a binary refrigeration system suitable for cooling a medium to be cooled at room temperature to a low temperature at once. be.

As shown in FIG.
The configuration is such that only the cooler 8 of the low-temperature side refrigerant circuit B obtains a low temperature. For this reason, it is good to keep the medium to be cooled at a low temperature, but when the medium to be cooled is room temperature and is to be cooled down to a predetermined low temperature, the evaporation temperature may change even though the inlet temperature of the medium to be cooled is high. must be set at a low temperature corresponding to the outlet temperature of the medium to be cooled, resulting in very inefficient operation.

(Object of the Invention) The present invention has been made in view of the above points, and an object of the present invention is to provide a dual refrigeration system that can improve operating efficiency and enhance the cooling effect.

(Structure of the Invention) In the present invention, conventionally, cooling was performed only in the cooler of the low-temperature side refrigerant circuit in a binary refrigeration system, but the high-temperature side refrigerant circuit with a high evaporation temperature is also separately cooled. This method attempts to solve the above-mentioned problems by providing a cooling device and having the device perform an auxiliary cooling action.

(Example) An embodiment of the present invention will be described below with reference to FIG.

The high temperature side refrigerant circuit A includes a compressor 11, a condenser 12, an expansion valve 13 as an expansion device, an evaporator 14, and an auxiliary cooler 2.
0 are sequentially connected through piping. On the other hand, the low temperature side refrigerant circuit B is configured by sequentially connecting a compressor 15, a condenser 16, an expansion valve 17, and a cooler 18 with piping, and also connects the evaporator 14 of the high temperature side refrigerant circuit A with the low temperature side refrigerant circuit. A cascade condenser 19 is formed by exchanging heat with the condenser 16 of B.
is formed. The medium 21 to be cooled is first cooled by the refrigerant RA in the auxiliary cooler 20 of the high temperature side refrigerant circuit A, and then cooled by the refrigerant RA in the low temperature side refrigerant circuit B. It is further cooled by the refrigerant RB in the cooler 18 to reach a desired temperature.

4.5, 22 is a wind tunnel forming a passage for the medium 21 to be cooled, and 23 is a blower fan.

In the configuration shown in FIG. 2 above, when the high temperature side compressor 11 and the low temperature side compressor 15 are operated simultaneously, the high temperature and high pressure refrigerant gas discharged from the compressor 11 in the high temperature side refrigerant circuit A is passed through the condenser 12. Condenses and liquefies.

This liquid refrigerant is led to a cascade condenser 19 after being depressurized by an expansion valve 13 . Here, the refrigerant discharged from the compressor 15 of the low temperature side refrigerant circuit B is cooled and liquefied, and the refrigerant itself is partially evaporated and vaporized. Subsequently, the remaining liquid refrigerant is also vaporized in the auxiliary cooler 20 and returns to the compressor 11 through the suction pipe to form a high temperature side refrigerant cycle.

On the other hand, in the low-temperature side refrigerant circuit B, the high-temperature and high-pressure refrigerant gas discharged from the compressor 15 is cooled by the refrigerant of the high-temperature side refrigerant circuit A in the cascade condenser 19, condenses and liquefies, and then is depressurized in the expansion valve 17. The refrigerant is led to the cooler 18, where it is evaporated and vaporized, and then returned to the compressor 15 to form a low-temperature side refrigerant cycle. Here, the medium 21 to be cooled is first cooled by the auxiliary cooler 20 of the high temperature side refrigerant circuit A, and then further cooled by the cooler 18 of the low temperature side refrigerant circuit B and the cascade condenser 19 and compressor 11 in the low temperature circuit A. However, it may be provided between the expansion valve 13 and the cascade capacitor 19 as shown by 20 in FIG. 6, or may be integrated with the cascade capacitor 19 as another embodiment.

As shown in FIG. 3, the cooling process of the medium to be cooled includes a cooling stage from a temperature ta1 in the auxiliary cooler 20 having a high evaporation temperature th.

The above description is only an example, and it goes without saying that the expansion valves 13, 17 may be capillary tubes, etc., and replacement of each structure with equivalents is also included within the technical scope of the present invention.

(Effects of the Invention) According to the present invention, compared to a conventional binary refrigeration system that is cooled only by the low-temperature side cooler, a part of the cooling effect can be supplemented with the higher evaporation temperature th, which improves overall operation. Efficiency can be improved. At the same time, the ratio of the cooling capacity to the sum of the discharge amounts of the two compressors can be increased. Furthermore, there are various effects such as being able to improve the cooling rate at startup.

[Brief explanation of the drawing]

FIG. 1 is a conventional refrigeration cycle diagram, FIG. 2 is a refrigeration cycle diagram showing an embodiment of the present invention, FIG. 3 is an explanatory diagram showing the cooling process of the medium to be cooled according to the present invention, and FIG. FIG. 5 shows a specific installation example of an auxiliary cooler and a cooler when the cooling medium is a liquid (or gas). FIG. 6 is a refrigeration cycle diagram showing another embodiment of the present invention. A...High temperature side refrigerant circuit, B...Low temperature side refrigerant circuit, 1
...High temperature side compressor, 13... Expansion device, 14... Evaporator, 16... Condenser, 18... Cooler, 19...
・Cascade condenser, 20・・Auxiliary cooler, 21・
...Medium to be cooled.

Claims (3)

[Claims] (1) The evaporator of the high temperature side refrigerant circuit and the condenser of the low temperature side refrigerant circuit are arranged in a heat exchange relationship to form a cascade condenser, and the expansion device including the cascade condenser of the high temperature side refrigerant circuit and the high temperature side An auxiliary cooler is provided in the low-pressure side pipe line between the compressors, and the auxiliary cooler is placed on the upstream side with respect to the medium to be cooled, and the cooler of the low temperature side refrigerant circuit is placed on the downstream side with respect to the medium to be cooled. A binary refrigeration device characterized by cooling in two stages. (2) The binary refrigeration system according to claim 1, wherein the auxiliary cooler is provided downstream of the cascade condenser in the high temperature side refrigerant circuit. (3) The binary refrigeration system according to claim 1, wherein the auxiliary cooler is provided upstream of the cascade condenser in the high temperature side refrigerant circuit.