JP2003075029A - Refrigerating cycle and air conditioner having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve high reliability in suppressing the problem that foreign substances attach to the exit and entrance portions of a narrow tube, with a simple and low-cost structure, irrespective of the switching operation between a cooling mode and a heating mode. SOLUTION: The refrigerating cycle employs an alternative refrigerant. The inner surface of the narrow tube 3a that constitutes an expander 3 is given a smoothening treatment, mold releasing treatment or hydrophilic treatment. The inner diameter of a connecting portion 3b located between the narrow tube 3a constituting the expander 3 and a circulating path 5 is made larger than that of the narrow tube 3a. The inner surface of the connecting portion 3b is given a rough surface treatment or lipophilic treatment to suppress attachment of foreign substances to the exit and entrance portions of the narrow rube 3a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating cycle and an air conditioner equipped with the same, and more particularly to a mixed refrigerant prepared by mixing at least one kind or two or more kinds in a fluorocarbon hydrogen refrigerant group, that is, an alternative refrigerant. The present invention relates to a refrigeration cycle in which a compressor, a condenser, an expander, and an evaporator are annularly connected by a circulation path, and an air conditioner using the same.

[0002]

2. Description of the Related Art A compressor used in a refrigeration cycle, especially a maintenance-free hermetic compressor, is disclosed in Japanese Patent Laid-Open No. 62-298.
As is known from Japanese Patent No. 680, etc., a compression mechanism that seals the mixed refrigerant and oil in a closed container, sucks the refrigerant and compresses it, and an oil pump that supplies the oil to each machine sliding portion. And an electric motor that drives them by a drive shaft.

On the other hand, a refrigerating cycle has been constituted by using a specific Freon R12 or a designated Freon R22 as the refrigerant. Specified CFCs are chemically stable, non-flammable and non-toxic compared to the previous refrigerants such as sulfur dioxide and methyl chloride,
It is widely used as an ideal refrigerant and has been used for many years.

Recently, however, it has been confirmed that a specific chlorofluorocarbon contains a chlorine atom in the molecule, which causes destruction of the ozone layer, and development and use of an alternative chlorofluorocarbon has been attempted.

As a highly practical alternative refrigerant, chlorine-free HFC (Hydro Fluoro Carbo) is used.
n), which is mentioned as a refrigerant (this is referred to as a chlorine-free refrigerant in this specification).
(Published by Nippon Kogyo Publishing).

By the way, since the non-chlorine type refrigerant does not contain chlorine, it cannot be expected to have the lubricity as in the conventional specific CFC. Therefore, the oil to be sealed in the closed container is particularly required to be compatible with the chlorine-free refrigerant. The oil enclosed in the airtight container is agitated by the chlorine-free refrigerant discharged into the airtight container from the compression mechanism and also by the rotor of the electric motor. At this time, since the oil is compatible with the non-chlorine type refrigerant, it often accompanies the refrigerant discharged into the closed container and reaches the details of the sliding parts of each machine well. ,
Lubrication performance is improved. Japanese Patent Laid-Open No. 6-
Synthetic oils called ester-based oils are used as known from Japanese Patent No. 235570.

[0007]

However, when the hermetic compressor is operated under the above-mentioned conditions and the refrigeration cycle is executed, foreign matter is not caught at the inlet and outlet of the narrow tube constituting the expander. Adhering to them impedes the flow of the refrigerant relatively early, and the refrigeration function deteriorates.

As a result of various experiments and examinations,
It was found that the cause was the use of ester oil as the oil compatible with the non-chlorine type refrigerant. If water invades at the time of sealing the circulation system of the refrigerant or if water is generated for some reason after the sealing, the ester oil is hydrolyzed by the water to produce a fatty acid.
Fatty acids corrode various parts of the circulatory system and form metal soaps to produce sludge. In addition, ester oil has low stability, and when the temperature rises, the foreign matter is dissolved and mixed in, and when the temperature falls, the foreign matter tends to precipitate. At the inlet of the thin tube, the flow velocity of the refrigerant is reduced, and the deposited foreign matter is apt to adhere to and clogging. Since the temperature drops at the outlet of the thin tube, foreign matter is likely to precipitate and adhere.

In the above-mentioned Japanese Patent Laid-Open No. 6-235570, a filter is provided in the middle of the refrigerant circulation path immediately before the upstream side in the refrigerant flow direction of the narrow tube to trap foreign matter, and the poor refrigerant flow in the thin tube. It discloses a refrigeration cycle that eliminates clogging.

However, the filter structure is complicated and expensive, and it is not possible to cope with the fact that the filter is deposited at the outlet of the thin tube due to a temperature decrease and immediately adheres thereto. Further, in the refrigerating cycle operated by the heat pump, when the flow direction of the refrigerant is reversed due to switching between cooling and heating, the filters need to be provided on both sides of the thin tube, which makes the filter more expensive.

An object of the present invention is to solve such a problem, and regardless of whether or not the cooling operation and the heating operation are switched, foreign matter adheres to the outlet or inlet of the thin tube with a simple and inexpensive structure. It is an object of the present invention to provide a highly reliable refrigeration cycle capable of suppressing the above and an air conditioner provided with the same.

[0012]

A refrigeration cycle and an air conditioner of the present invention use a chlorine-free refrigerant, and a refrigeration cycle in which a compressor, a condenser, an expander, and an evaporator are annularly connected by a circulation path. However, when the refrigeration cycle is switched to both cooling and heating operations by using a synthetic oil compatible with a non-chlorine refrigerant, foreign matter mixed in the refrigerant and deposited is the inlet of the thin tube. Easily adheres to the outlet and outlet.

However, according to the present invention, in particular, no matter which direction the refrigerant flows, the ends of the narrow tube, which are the inlet and the outlet, project into the connecting portion wider than this, and the outer surface of the projecting portion and the wide side on the circulation path side. The flow of the refrigerant is stagnant between the inner surface of the connection part and more foreign matter is adhered to the outer surface of the protruding part and the inner surface of the connection part, and the foreign matter adhered to the inner surface of the projection part and the connection part. Since it does not affect the main flow of the refrigerant and prevents the capillaries from being blocked for a longer period of time, the refrigerating function of the refrigerating cycle is stable for a longer period of time and has higher reliability.

Moreover, the inner surface of the thin tube constituting the expander is subjected to smoothing treatment, mold releasing treatment or hydrophilic treatment so that the smoothness of the inner surface of the thin tube makes it difficult for foreign matter to be caught or attached, or the inner surface of the thin tube is separated. Foreign matter is less likely to adhere due to the mold surface, or oily foreign matter can be prevented from adhering due to the hydrophilicity of the inner surface of the thin tube. It is larger than a thin tube, and the inner surface of the connection part is roughened or lipophilicized,
The foreign matter in the refrigerant is removed by positively adhering the foreign matter to the inner surface of the roughened wide connection part, and the adhered foreign matter does not affect the flow of the refrigerant. It becomes difficult for foreign matter to adhere, or oily foreign matter is positively adhered to the inner surface of the wide connection part made lipophilic to remove it from the inside of the refrigerant, and this adhered foreign matter does not affect the flow of the refrigerant, Since foreign matter is less likely to adhere to the inner surface of the entrance / exit of the thin tube, the refrigeration cycle has high reliability, and the structure is not particularly complicated and is inexpensive.

The connecting portion may be fitted over the thin tube and the circulation path.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the present invention will be described below with reference to FIGS. 1 to 15 together with some reference examples.

In this embodiment and the reference example, a refrigerating system is used in which a compressor 1, a condenser 2, an expander 3 and an evaporator 4 are annularly connected by a circulation path 5 as shown in FIG. Foreign matter mixed in the refrigerant, regardless of whether the refrigeration cycle is switched between cooling operation and heating operation by using a synthetic oil that is compatible with a non-chlorine refrigerant, is a cycle. May adhere to the entrance and exit.
A four-way valve 20 for switching between the cooling operation and the heating operation is provided in the middle of the circulation path 5, and during the cooling operation, the refrigerant flows to the condenser 2, the expander 3 and the evaporator 4 shown in FIG. In contrast to the flow in the direction indicated by, the flow of the coolant is reversed in the heat pump. As a result, the condenser 2 functions as an evaporator and the evaporator 4 functions as a condenser during the cooling operation.

In such a refrigerating cycle, a non-chlorine refrigerant and an ester oil, for example, are used as a synthetic oil compatible with the non-chlorine refrigerant, and foreign substances mixed in or precipitated in the refrigerant during cooling operation or heating operation. However, they are likely to adhere to the ends of the narrow tube 3a constituting the expander 3 that are the inlet and the outlet, especially the inner surface. It is sometimes the case that the flow of the refrigerant is obstructed or clogged due to the adhesion of such foreign matter, and the refrigeration cycle function is deteriorated early.

(Reference Example 1) However, in this reference example, as shown in FIG. 2, at the connecting portion 3b between the narrow tube 3a constituting the expander 3 and the circulation path 5, the inner diameter is increased from the circulation path 5 side to the narrow tube 3a side. There is provided a slope portion 6 which gradually decreases. This slope part 6
No matter which direction the refrigerant flows in the cooling operation and the heating operation, a wide space 6a is formed at each end that serves as an entrance / exit of the thin tube 3a, and even if foreign matter adheres to the inner surface of this portion, this adheres. Depending on the size of the space of the connecting portion 3b, the foreign matter may be a thin tube 3a.
Also, since it does not affect the main flow of the refrigerant in the connection portion 3b and prevents the thin tube 3a from being blocked, the refrigeration function of the refrigeration cycle becomes stable for a long period of time and has high reliability. Moreover, the structure can be simple and inexpensive because it can be dealt with only by improving the pipe shape of each connecting portion 3b between the thin tube 3a and the circulation path 5.

Further, the connecting portion 3b may be formed integrally with one or both of the circulation path 5 and the thin tube 3a. However, in the present embodiment, the connecting portion 3b is provided separately, and the circulation path 5, the thin tube 3a, and the connecting portion 3b are connected to each other. Therefore, the slope shape of the connecting portion 3b can be easily processed by a single component. Can be achieved. In addition, in the present embodiment, the independent connecting portion 3b is connected to the circulation path 5
Also, since it is externally fitted and connected to the end of the thin tube 3a, this connecting structure has the connecting portion 3b having the slope portion 6 as it is.
By making the space larger, it is possible to further reduce the influence of the adhesion of the foreign matter on the flow of the refrigerant,
It is advantageous for long-term stability of the function of the refrigeration cycle.

The connecting portion 3b includes the circulation path 5 and the thin tube 3.
Along with a, they may be made of conventional copper and may be connected to each other by brazing. However, other materials and bonding structures can be employed.

(Reference Example 2) This reference example follows the structure of Reference Example 1, and the same members are denoted by the same reference numerals and duplicate description will be omitted. As shown in FIG. 3, a thin tube 3a forming the expander 3 is projected into the connecting portion 3b on the circulation path 5 side thereof. No matter which direction the refrigerant flows, the ends of the thin tube 3a, which are the inlet and the outlet, project into the connecting portion 3b having a larger space 6a having a larger diameter, and the projecting end 3
The flow of the refrigerant is stagnated in the portion 6b between the outer surface of c and the inner surface of the wide connection portion 3b on the circulation path 5 side, and these protruding end portions 3c
And the inner surface of the connecting portion 3b and the portion 6 between them.
Since more foreign matter is attached to b, and the foreign matter that is attached does not affect the main flow of the refrigerant in the thin tube 3a and the connecting portion 3b and prevents the thin tube 3a from being blocked for a longer period of time, The refrigerating function of the refrigerating cycle is stable for a longer period of time and has higher reliability than that of the first embodiment. Moreover, the structure can be simple and inexpensive because it can be dealt with only by improving the connection state of each connecting portion 3b between the thin tube 3a and the circulation path 5.

In this reference example, it is not necessary to follow the first example, and the end of the circulation path 5 having a large diameter is closed to the end of the thin tube 3a having a small diameter. Even if only it protrudes inward, the action and effect peculiar to the present embodiment described above can be exhibited, and the long-term stability of the function of the refrigeration cycle can be achieved to some extent.

Reference Example 3 This reference example is a follow-up of Reference Examples 1 and 2. The following description will be given of points unique to the present embodiment while giving the same reference numerals to the same members. As shown in FIG. 4, the protruding end portion 3c of the thin tube 3a to the connecting portion 3b is opened obliquely with respect to the axis thereof.

As a result, the opening area of the narrow tube 3a toward the wide space 6a on the circulation path 5 side is large, and it becomes difficult for foreign matter to be caught in the opening of the projecting end portion 3c which is the entrance / exit of the thin tube 3a, so that the structure is complicated. Thin tube 3a
The function of preventing foreign matter from adhering to the entrance / exit of the door is further improved. This reference example does not necessarily have to follow the reference example 1.

Reference Example 4 This Reference Example follows Reference Examples 1 and 2, and the same reference numerals are given to the same members as those, and the points peculiar to the present embodiment will be described. As shown in FIG. 5, a hole 3d is provided in the peripheral wall of the projecting end 3c of the thin tube 3a.

Thus, the entrance and exit of the refrigerant between the thin tube 3a and the wide connection portion 3b on the side of the circulation path 5 is smoothed by the hole 3d, and the smooth refrigerant flow is such that foreign matter is introduced into and exited from the thin tube 3a. Since it is prevented from adhering to the protruding end portion 3c, the function of preventing foreign matter from adhering to the entrance / exit portion of the thin tube 3a can be further improved under a simple additional condition of providing the hole 3d. This reference example does not necessarily need to follow the reference example 1.

Reference Example 5 This Reference Example follows the refrigeration cycle of Reference Examples 1 to 4, and as shown in FIG. 6, a plurality of thin tubes constituting the expander 3 having different inner diameters, for example, Three thin tubes 3e to 3g are connected in parallel. In such a case, since the refrigerant is clogged in order from the small tube 3g having a small inner diameter where it is difficult to flow, it is possible to prevent the entire thin tubes 3e to 3g from being clogged early and maintain a normal function for a long time. The number of the thin tubes 3e to 3g increases, and the required diameter of the thin tubes 3e to 3g decreases in proportion to the increase in the number of the thin tubes 3e to 3g. Therefore, the structure is not particularly complicated.

At the connecting portion 3b between the plurality of thin tubes 3e to 3g and the circulation path, the inner diameter is gradually increased from the circulation path 5 side to each thin tube 3e to 3g side between the circulation path 5 and the thin tubes 3e to 3g. 3e ~
A slope portion 7 that is collectively connected to 3 g is provided. A space 7a larger than the circulation path 5 by the slope portion 7 can be used to collectively connect the plurality of thin tubes 3e to 3g, and the large space 7a prevents the foreign matter from adhering to the refrigerant flow and causing clogging. The occurrence can be further prevented.

Moreover, each thin tube 3e to 3g is connected to the slope portion 7.
By projecting inward, the outer surface of each protruding end portion 3c of each thin tube 3e to 3g and the inner surface of the slope portion 7 and the portion 7b between them can exhibit the action and effect peculiar to the second reference example. .

The present invention is not limited to this, and at least one of the structures of Reference Examples 3 and 4 may be adopted together, and the action and effect unique to the adopted structure can be exhibited.

Reference Example 6 In this Reference Example, a plurality of thin tubes 3 having different lengths as shown in FIG.
Since h to 3j are connected in parallel and the long tubes 3h in which the refrigerant is difficult to flow are sequentially clogged, it is possible to prevent the entire thin tubes 3h to 3j from clogging early and maintain a normal function for a long time. In addition, the number of the thin tubes 3h to 3j only increases, and the required diameter of the thin tubes 3h to 3j decreases in proportion to the increase in the number of the thin tubes 3h to 3j. Therefore, the structure is particularly complicated. do not become.

It should be noted that an embodiment in which the configurations of both Reference Examples 5 and 6 are combined can be used. In this case, it is easy to classify the difficulty of the flow of the refrigerant and the long thin tube is formed to be the thinnest. It is possible to further increase the difficulty of the refrigerant flow, and conversely, by forming the short thin tube to be the thickest, the ease of the refrigerant flow can be further increased.

Reference Example 7 This Reference Example is an alternative to Reference Examples 5 and 6, in which a plurality of thin tubes 3k, 3m, 3n constituting the expander 3 are respectively provided as shown in FIG. 8 (a). The thin tube 3 to be used, which is connected by holding the on-off valves 8 to 10.
k, 3m, and 3n are made one by opening and closing the opening / closing valves 8 to 10, and the thin tubes 3k, 3m, and 3n to be used are sequentially switched depending on the degree of blockage when foreign matter of the thin tubes 3k, 3m, and 3n being used is clogged. Therefore, it is possible to prevent the entire thin tubes 3k, 3m, 3n from being clogged at an early stage, and the switching control is performed by a control means for controlling the operation of the refrigeration cycle itself, for example, shown in FIG. Microcomputer M. By using C, the normal function can be maintained for a long period of time without making the structure particularly complicated. Microcomputer M. C is for such control,
Open / close valve 8 each time an automatic or manual clogging signal is received
Capillaries to be used by sequentially changing the open ones up to 9
Switch k, 3m, and 3n. The microcomputer M.M. In order to perform the automatic switching, C designates the refrigerant passage resistance and the like in each of the thin tubes 3k, 3m, 3n being used, and determines an abnormal pressurization of the refrigerant by an internal function so that a clogging signal is automatically obtained. You can also

Reference Example 8 This Reference Example, which is an alternative to Reference Examples 5 to 7, belongs to a refrigeration cycle having a heat pump switching valve as in Reference Example 1, and as shown in FIG.
The thin tubes that make up the expander 3 are one-way valves 11 and 1 respectively.
The thin tubes 3p and 3q having 2 are connected to one-way valves 11 and 1
The two-way valve 11 is made up of two types connected in parallel so that the directions of 2 are reversed, and the one-way valve 11, corresponding to the direction of the flow of the refrigerant being reversed in the cooling operation and the heating operation, 1
Since the thin tubes through which the refrigerant flows are used differently during the cooling operation and the heating operation due to the restriction of the flow direction of 2, it is possible to halve the possibility that foreign matter adheres to the thin tubes 3p and 3q and is clogged.
Therefore, the refrigeration cycle is highly reliable, and the structure is not complicated and is inexpensive.

The thin tube having the one-way valve 11 and the thin tube having the one-way valve 12 may be composed of a plurality of tubes having different thicknesses and lengths so that they can be sequentially closed. .

Reference Example 9 This Reference Example follows the refrigeration cycle of Reference Example 1, and as shown in FIG.
A plurality of thin tubes constituting the expander 3, for example, two thin tubes 3
r and 3s are connected in series through a connecting pipe 13 provided between them, and the inner diameter of the connecting pipe 13 is made larger than the inner diameters of the thin tubes 3r and 3s. To prevent the foreign matter from affecting the flow of the refrigerant, and to divide the thin tube by connecting pipes to prevent the foreign matter from affecting the flow of the refrigerant. It can be shortened to a fraction of the length to make it more difficult for foreign matter to be clogged in the thin tube, which makes the refrigeration cycle highly reliable, and in both cases, the structure is not particularly complicated and is inexpensive.

In this reference example, it is possible to adopt the structure peculiar to the reference examples 2 to 8 so as to exert the operation effect peculiar to them.

(Embodiment 1) This embodiment follows the refrigeration cycle of Reference Example 1, and as shown in FIG. 11, the inner surface of the thin tube 3a constituting the expander 3 is smoothed. Therefore, the smoothness of the smoothed surface 21 on the inner surface of the thin tube 3a makes it difficult for foreign matter to be caught or adhered, which makes the refrigeration cycle highly reliable, and the structure is not particularly complicated and is inexpensive. The smoothing treatment can be performed by polishing treatment such as blasting, plating, or any other method already known.

(Embodiment 2) This embodiment follows the refrigeration cycle of Reference Example 1 and this embodiment, and as shown in FIG. 12, a thin tube 3a constituting the expander 3 is formed.
Of the inner surface of the thin tube 3a, it becomes difficult for foreign matter to adhere due to the releasability of the release layer 22 on the inner surface of the thin tube 3a, the refrigeration cycle becomes highly reliable, and if the structure is particularly complicated. It is inexpensive.

The mold release treatment includes, for example, fluorine coating treatment. However, it can be done by other methods already known.

(Embodiment 3) This embodiment follows the refrigeration cycle of Reference Example 1, and as shown in FIG. 13, the inner surface of the thin tube 3a constituting the expander 3 is hydrophilically treated. Therefore, the hydrophilicity of the hydrophilic treatment layer 23 on the inner surface of the thin tube 3a makes it difficult for oily foreign matter to adhere, which makes the refrigeration cycle highly reliable, and the structure is not particularly complicated and is inexpensive. The hydrophilic treatment preferably has a composition containing a large amount of nitrogen or sulfur atoms, and the nitriding treatment is suitable. However, it can be done by other methods already known.

(Embodiment 4) This embodiment follows the structure of Reference Example 1, and as shown in FIG.
Connection part 3b between thin tube 3a constituting expander 3 and circulation path 5
Has a larger inner diameter than the thin tube 3a, and the inner surface of the connecting portion 3b is roughened.
The foreign matter in the refrigerant is removed by positively adhering the foreign matter to the inner surface of the slope portion 6 having a, and the adhered foreign matter does not affect the flow of the refrigerant. Foreign matter is less likely to adhere, the refrigeration cycle has high reliability, and the structure is not particularly complicated and is inexpensive. The rough surface treatment can be performed by chemical etching, blast treatment, or the like. However, it is not limited to these,
Other methods already known can also be adopted. The present embodiment can be applied to the reference examples 2 to 5, 8 and the third embodiment.

(Fifth Embodiment) This embodiment is an alternative to the fourth embodiment, and as shown in FIG. 15, a lipophilic treatment layer 25 in which the inner surface of the connecting portion 3b of the expander 3 is subjected to lipophilic treatment. The oily foreign matter is positively adhered to the inner surface of the slope portion 6 having the wide space 6b made lipophilic so that the foreign matter is less likely to adhere to the inner surfaces such as the thin tubes 3a.
The refrigeration cycle has high reliability, and the structure is not particularly complicated and is inexpensive. The lipophilic treatment can be performed by film coating with an alcohol resin or the like.

[0045]

As described above, according to the invention of claims 1 to 3, no matter what the direction of the refrigerant flows in the cooling operation and the heating operation, foreign matter will be present at the ends of the thin tubes, which are the inlet and the outlet. It is possible to prevent the adhesion of the refrigerant to block the flow of the refrigerant and the blockage of the thin tube, to stabilize the refrigeration function of the refrigeration cycle for a long period of time and to make it highly reliable, and the structure is particularly complicated. It is also cheap because it does not happen.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a heat pump type refrigeration cycle showing an embodiment of the present invention and a reference example.

FIG. 2 is a cross-sectional view showing a connection structure between a circulation path and an expander of Reference Example 1 of the present invention.

FIG. 3 is a cross-sectional view showing a connection structure between a circulation path and an expander of Reference Example 2 of the present invention.

FIG. 4 is a cross-sectional view showing a connection structure between a circulation path and an expander of Reference Example 3 of the present invention.

FIG. 5 is a cross-sectional view showing a connection structure between a circulation path and an expander of Reference Example 4 of the present invention.

FIG. 6 is a cross-sectional view showing a connection structure between a circulation path and an expander of Reference Example 5 of the present invention.

FIG. 7 is a cross-sectional view showing a connection structure between a circulation path and an expander of Reference Example 6 of the present invention.

FIG. 8 is a cross-sectional view showing a connection structure between a circulation path and an expander of Reference Example 7 of the present invention, and a block diagram of control means.

FIG. 9 is a cross-sectional view showing a connection structure between a circulation path and an expander of Reference Example 8 of the present invention.

FIG. 10 is a cross-sectional view showing a connection structure between a circulation path and an expander of Reference Example 9 of the present invention.

FIG. 11 is a cross-sectional view showing a part of a thin tube forming the expander according to the first embodiment of the present invention.

FIG. 12 is a cross-sectional view showing a part of a thin tube forming an expander according to a second embodiment of the present invention.

FIG. 13 is a cross-sectional view showing a part of a thin tube forming an expander according to a third embodiment of the present invention.

FIG. 14 is a cross-sectional view showing a connection structure between a circulation path and an expander according to a fourth embodiment of the present invention.

FIG. 15 is a sectional view showing a connection structure between a circulation path and an expander according to a fifth embodiment of the present invention.

[Explanation of symbols]

1 compressor 2 condenser 3 expander 3a, 3e to 3k, 3m, 3n, 3p to 3s thin tubes 3b connection part 3c protruding end 3d hole 4 evaporator 5 circuit 6, 7 slope section 6a, 7a space 8, 9, 10 open / close valve 11,12 One-way valve 13 Connection tube 20 four-way valve 21 smoothed surface 22 Release layer 23 Hydrophilic treatment layer 24 rough surface 25 Lipophilic treatment layer

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hironao Numamoto             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Shinji Watanabe             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Akira Fujitaka             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Haneda Kanji             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Yoshinori Kobayashi             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Yuichi Yakumaru             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Yamaguchi Adult             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd.

Claims (3)

[Claims] 1. A compressor, a condenser, and a non-chlorine refrigerant are used.
This is a refrigeration cycle in which an expander and an evaporator are connected in a loop by a circulation path, and the inner surface of the narrow tube that constitutes the expander is subjected to smoothing treatment, mold release treatment or hydrophilic treatment to circulate with the narrow tube that constitutes the expander. A refrigeration cycle characterized in that an inner diameter of a connection portion with a passage is made larger than that of a thin tube, and an inner surface of the connection portion is roughened or lipophilicized. 2. The refrigerating cycle according to claim 1, wherein the connecting portion is fitted onto the narrow tube and the circulation path. 3. An air conditioner comprising the refrigeration cycle according to any one of claims 1 and 2.