JP2001041599A - Refrigerating machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a circuit configuration of a low temperature side refrigerating cycle. SOLUTION: In the refrigerating machine having low temperature side and high temperature side refrigerating cycles A and B comprising a sealed container 13 having a refrigerant-refrigerant heat exchanger X operating as a condenser in the low temperature side refrigerating cycle A, and a heat transfer tube 14 arranged in the container 13 and operating as an evaporator in the high temperature side refrigerating cycle B, a discharge gas refrigerant GxA from a compressor 1A in the cycle A is supplied to the container 13 for constituting the exchanger X and cooled by an evaporating latent heat of a low pressure liquid refrigerant LxB in the cycle B flowing through the tube 14 for constituting the exchanger X, condensed to be liquefied, temporarily stored in the container 13, and the liquid refrigerant LxA stored in the container 13 is further cooled (that is, supercooled) by the evaporating latent heat of the refrigerant LxB flowing through the tube 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a refrigeration system comprising a refrigerant / refrigerant heat exchanger comprising two refrigeration cycles and exchanging heat between a discharged gas refrigerant in one refrigeration cycle and a low-pressure liquid refrigerant in the other refrigeration cycle. It concerns the device.

[0002]

2. Description of the Related Art Conventionally, a refrigerating apparatus including a refrigerant / refrigerant heat exchanger which comprises two refrigerating cycles and exchanges heat between a discharged gas refrigerant in one refrigerating cycle and a low-pressure liquid refrigerant in the other refrigerating cycle is often used. Are known.

For example, as shown in FIG. 4, the refrigerating apparatus includes a compressor 1A, a refrigerant / refrigerant heat exchanger X, a temperature-sensitive expansion valve 3A acting as a pressure reducing mechanism, and an evaporator 4A, which are sequentially connected by a refrigerant pipe. A high-temperature side refrigeration cycle B in which a compressor 1B, a condenser 2B, a temperature-sensitive expansion valve 3B acting as a pressure reducing mechanism, and a refrigerant / refrigerant heat exchanger X are sequentially connected by refrigerant piping. The above two refrigerating cycles are provided.

In the refrigerating apparatus having the above-described structure, the refrigerant / refrigerant heat exchanger X is used as a refrigerant GxA discharged from the compressor 1A.
A plate-type heat exchanger or a double-pipe heat exchanger provided with a passage through which the gas flows and a passage through which the low-pressure liquid refrigerant LxB depressurized by the temperature-sensitive expansion valve 3B flows.

When the refrigerant / refrigerant heat exchanger X having the above structure is used, a liquid receiver 5A for storing the liquid refrigerant LxA condensed and liquefied in the refrigerant / refrigerant heat exchanger X, and a supercooler for supercooling. The low-temperature side refrigeration cycle A is connected to the heat exchanger 6A.
Had to be provided.

The subcooling heat exchanger 6A is provided with the liquid receiver 5A.
From the liquid refrigerant LxA to the temperature-sensitive expansion valve 7A
The cooling is performed by the latent heat of vaporization of the liquid refrigerant LxA supplied under reduced pressure. In some cases, the subcooling heat exchanger is configured to cool the liquid refrigerant from the liquid receiver with the suction gas refrigerant that is returned from the evaporator.

In FIG. 4, reference numeral 8A denotes an accumulator, 9A denotes a temperature-sensitive cylinder of the temperature-sensitive expansion valve 3A, 9B denotes a temperature-sensitive cylinder of the temperature-sensitive expansion valve 3B, 10A denotes a pressure equalizing pipe of the temperature-sensitive expansion valve 3A, 11
A is a temperature-sensitive cylinder of the temperature-sensitive expansion valve 7A, and 12A is a check valve.

[0008]

However, in the conventional refrigeration apparatus described above, in the low-temperature refrigeration cycle A, in addition to the refrigerant / refrigerant heat exchanger X, the liquid receiver 5A and the supercooling heat exchanger 6A are provided. There is a problem that the circuit configuration of the low-temperature side refrigeration cycle A becomes complicated because it is necessary.

[0009] The present invention has been made in view of the above points, and has as its object to simplify the circuit configuration of a low-temperature refrigeration cycle.

[0010]

According to the first aspect of the present invention, as a means for solving the above-mentioned problems, the compressor in the low-temperature side refrigeration cycle A includes a low-temperature side refrigeration cycle A and a high-temperature side refrigeration cycle B. Gas refrigerant G discharged from 1A
xA and the low-pressure liquid refrigerant L in the high-temperature side refrigeration cycle B
a refrigerant / refrigerant heat exchanger X for exchanging heat with xB, wherein the refrigerant / refrigerant heat exchanger X is used as a condenser in the low-temperature side refrigerant cycle A; 13 and a heat transfer tube 14 acting as an evaporator in the high-temperature side refrigeration cycle B.

With the above configuration, the gas refrigerant GxA discharged from the compressor 1A in the low-temperature side refrigeration cycle A is supplied to the closed vessel 1 constituting the refrigerant / refrigerant heat exchanger X.
3 is cooled and condensed and liquefied by the latent heat of vaporization of the low-pressure liquid refrigerant LxB in the high-temperature side refrigeration cycle B flowing through the heat transfer tubes 14 constituting the refrigerant / refrigerant heat exchanger X. Accumulate in The liquid refrigerant LxA accumulated in the closed container 13 is further cooled (ie, supercooled) by the latent heat of evaporation of the low-pressure liquid refrigerant LxB flowing in the heat transfer tube 14. That is, the refrigerant / refrigerant heat exchanger X
Has a function as a condenser, a liquid receiver and a supercooling heat exchanger in the low-temperature side refrigeration cycle A, and also has a function as an evaporator in the high-temperature side refrigeration cycle B.

As in the second aspect of the present invention, the first aspect
In the refrigerating apparatus described above, when an external grooved tube is used as the heat transfer tube 14, the heat transfer efficiency of the refrigerant / refrigerant heat exchanger X (condensing performance and Supercooling performance) will be improved.

[0013]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

This refrigeration apparatus is composed of two refrigeration cycles, a low-temperature refrigeration cycle A and a high-temperature refrigeration cycle B, as described in the section of the prior art. / Refrigerant heat exchanger X for exchanging heat between the gas refrigerant GxA discharged from the compressor 1A and the low-pressure liquid refrigerant LxB in the high-temperature side refrigeration cycle B
It is provided with.

The low-temperature side refrigeration cycle A includes a compressor 1
A, a refrigerant / refrigerant heat exchanger X, a temperature-sensitive expansion valve 3A acting as a pressure reducing mechanism, and an evaporator 4A are sequentially connected by a refrigerant pipe.
The compressor 1B, the condenser 2B, the temperature-sensitive expansion valve 3B acting as a pressure reducing mechanism, and the refrigerant / refrigerant heat exchanger X are sequentially connected by a refrigerant pipe.

Reference numeral 8A denotes an accumulator, 9A denotes a temperature-sensitive cylinder of the temperature-sensitive expansion valve 3A, 9B denotes a temperature-sensitive cylinder of the temperature-sensitive expansion valve 3B,
10A is a pressure equalizing pipe of the temperature-sensitive expansion valve 3A, 11A is a temperature-sensitive cylinder of the temperature-sensitive expansion valve 7A, and 12A is a check valve.

In the present embodiment, the refrigerant / refrigerant heat exchanger X includes a closed container 13 acting as a condenser in the low-temperature side refrigerant cycle A, And a heat transfer tube 14 acting as an evaporator in the refrigeration cycle B.

As shown in FIGS. 2 and 3, the closed vessel 13 is formed in a cylindrical shape, and an inlet pipe 15A to which the gas refrigerant GxA discharged from the compressor 1A is supplied is connected to an upper portion of the side wall, and An outlet pipe 16A to the thermal expansion valve 3A is connected to a lower portion of the side wall.

On the other hand, the heat transfer tube 14 employs an external grooved tube (trade name, thermo excel tube) having a serrated fin formed on the outer peripheral surface. They are arranged vertically. By the way, since it is difficult to bend the thermo excel pipe, the lower end of the first heat transfer pipe 14 is connected to an inlet pipe (connected to the thermosensitive expansion valve 3B) 15B that penetrates the bottom of the closed vessel 13, and
The upper end of the second heat transfer tube 14 and the upper end of the second heat transfer tube 14 are connected by a U-shaped connection pipe 17, and the second heat transfer tube 14
The lower end of the third heat transfer tube 14 is connected to the lower end of the third heat transfer tube 14 by a U-shaped connection pipe 18, and the upper end of the third heat transfer tube 14 is connected to an outlet pipe penetrating the side wall of the hermetic container 13 (connected to the compressor 1 </ b> B). ) 16B. In this case, the heat transfer tubes 14,
It is desirable that the lower portions of the pipes 14 and 14 are immersed in the liquid refrigerant LxA condensed and liquefied in the closed vessel 13. In the case where the heat transfer tube 14 is bendable (for example, can be processed into a hairpin shape), the heat transfer tube 14 may be a series of tubes extending to the inlet pipe 15B and the outlet pipe 16B.

In the refrigeration apparatus configured as described above, the following operational effects can be obtained.

Compressor 1A in low-temperature side refrigeration cycle A
Is supplied to the closed vessel 13 forming the refrigerant / refrigerant heat exchanger X, and flows through the heat transfer tube 13 forming the refrigerant / refrigerant heat exchanger X. The liquid is cooled by the latent heat of vaporization of LxB, condensed and liquefied, and temporarily stored in the closed container 13.
The liquid refrigerant LxA accumulated in the closed container 13 is further cooled (ie, supercooled) by the latent heat of evaporation of the low-pressure liquid refrigerant LxB flowing in the heat transfer tube 14, and then the temperature-sensitive expansion valve 3
The pressure is reduced by A and supplied to the evaporator 4A to be used as a cooling heat source. That is, the refrigerant / refrigerant heat exchanger X has a function as a condenser, a liquid receiver, and a subcooling heat exchanger in the low-temperature side refrigeration cycle A, and also has a function as an evaporator in the high-temperature side refrigeration cycle B. It becomes. Therefore, the circuit configuration of the low temperature side refrigeration cycle A can be simplified.

Further, since the outer grooved tube (that is, the thermo excel tube) used as the heat transfer tube 14 has extremely high heat transfer performance, the heat exchange efficiency (condensing performance) of the refrigerant / refrigerant heat exchanger X is high. And supercooling performance) can be sufficiently ensured.

[0023]

According to the first aspect of the present invention, there is provided a low-temperature refrigeration cycle A and a high-temperature refrigeration cycle B. In the low-temperature refrigeration cycle A, the discharge gas refrigerant GxA from the compressor 1A and the high-temperature refrigeration cycle. In the refrigerating apparatus provided with the refrigerant / refrigerant heat exchanger X for exchanging heat with the low-pressure liquid refrigerant LxB in the cycle B, the closed vessel which operates the refrigerant / refrigerant heat exchanger X as a condenser in the low-temperature side refrigerant cycle A 13 and a heat transfer tube 14 disposed in the closed vessel 13 and acting as an evaporator in the high-temperature side refrigeration cycle B, so that the discharge gas refrigerant GxA from the compressor 1A in the low-temperature side refrigeration cycle A is High-temperature side refrigeration cycle B, which is supplied to the closed vessel 13 constituting the refrigerant / refrigerant heat exchanger X and flows through the heat transfer tube 14 constituting the refrigerant / refrigerant heat exchanger X Definitive is condensed and liquefied is cooled by latent heat of vaporization of the low-pressure liquid refrigerant LXB, accumulate temporarily on the sealed container 13, the liquid refrigerant LxA accumulated in the closed vessel 13
Is further cooled by the latent heat of vaporization of the low-pressure liquid refrigerant LxB flowing through the heat transfer tube 14 (ie, supercooled), so that the refrigerant / refrigerant heat exchanger X is condensed in the low-temperature side refrigeration cycle A. High-temperature refrigeration cycle B
Has a function as an evaporator, and has an effect that the circuit configuration in the low-temperature side refrigeration cycle A can be simplified.

As in the invention of claim 2, claim 1
In the refrigerating apparatus described above, when an external grooved tube is used as the heat transfer tube 14, the heat transfer efficiency of the refrigerant / refrigerant heat exchanger X (condensing performance and Supercooling performance) will be improved.

[Brief description of the drawings]

FIG. 1 is a refrigerant piping system diagram of a refrigeration apparatus according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a refrigerant / refrigerant heat exchanger in the refrigeration apparatus according to the embodiment of the present invention.

FIG. 3 is a cross-sectional view of a refrigerant / refrigerant heat exchanger in the refrigeration apparatus according to the embodiment of the present invention.

FIG. 4 is a refrigerant piping system diagram of a conventional refrigeration apparatus.

[Explanation of symbols]

1A and 1B are compressors, 2B is a condenser, 3A and 3B are pressure reducing mechanisms (thermal expansion valves), 4A is an evaporator, 13 is a closed vessel,
14 is a heat transfer tube, A is a low-temperature refrigeration cycle, B is a high-temperature refrigeration cycle, X is a refrigerant / refrigerant heat exchanger, GxA is a discharge gas refrigerant, and LxB is a low-pressure liquid refrigerant.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Takeo Ueno 1304 Kanaokacho, Sakai-shi, Osaka Daikin Industries Inside Kanaoka Plant of Sakai Seisakusho Co., Ltd. (72) Masaaki Takegami 1304 Kanaokacho, Sakai-shi, Osaka Daikin Industries Co., Ltd. Sakai Factory Kanaoka Factory

Claims (2)

[Claims] 1. A low-temperature side refrigeration cycle (A) and a high-temperature side refrigeration cycle (B), and a discharge gas refrigerant (G) from a compressor (1A) in the low-temperature side refrigeration cycle (A).
xA) and a refrigerant / refrigerant heat exchanger (X) for exchanging heat between the low-pressure liquid refrigerant (LxB) in the high-temperature side refrigeration cycle (B), wherein the refrigerant / refrigerant heat exchanger (X ), A closed vessel (13) acting as a condenser in the low-temperature side refrigerant cycle (A), and an evaporator disposed in the closed vessel (13) and acting as the evaporator in the high-temperature side refrigeration cycle (B). A refrigeration apparatus characterized by comprising a heat transfer tube (14). 2. The refrigeration system according to claim 1, wherein an outer grooved tube is used as the heat transfer tube.