JP2000297971A - Refrigerating cycle and manufacture of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve an expansion efficiency in a capillary tube for a refrigerating/air-conditioning device and prevent the lowering of flow rate of refrigerant, which is due to the adhesion of sludge in the same tube. SOLUTION: A capillary tube 28 is provided with at least one place of projected part 29 on the inner surface of the same to improve an expansion efficiency by the choking effect of refrigerant, which is caused by the projected part 29. The projected part 29 can be formed easily by applying a pushing force from the outside of the capillary tube 28 to deform the same through plastic deformation. On the other hand, the film 30 of a water repellent material is formed on the inner surface of the capillary tube 28 whereby the adhesion of sludge can be reduced remarkably. The film 30 of water repellent material is formed by forming the film 31 of a surfactant on the inner surface of the capillary tube 28, then, the water repellent material is applied thereon whereby an uniform film can be formed while a firing process is applied if necessary in accordance with the nature of the water repellent material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration cycle used for refrigeration, refrigeration equipment and air conditioning equipment. And a method of manufacturing the same.

[0002]

2. Description of the Related Art A recent technical trend of a refrigeration / air-conditioning apparatus according to the prior art, particularly focusing on a capillary tube, will be described below with reference to the drawings. FIG.
It is a refrigerant circuit diagram showing a refrigeration cycle shown in -132372 gazette. In FIG. 7, 1 is a compressor, 2 is an outdoor heat exchanger (condenser), 3 is a capillary tube, 4 is an indoor heat exchanger (evaporator), and 5 is a four-way valve, which are closed by piping. They are connected to form a refrigerant circuit. The refrigerant discharged from the compressor 1 circulates through the refrigerant circuit. In the circulation, the refrigerant gas, which has become high pressure in the compressor 1, radiates and liquefies in the outdoor heat exchanger (condenser) 2 and then drops in pressure in the capillary tube 3 serving as an expansion valve. The gas is vaporized by the exchanger (evaporator) 4, and at that time, a refrigerating action is performed to remove heat from the surroundings. The vaporized refrigerant is compressed again by the compressor 1, and thereafter, the above cycle is repeated, and the refrigerant circulates in the direction of arrow 6 in the figure.

FIG. 8 is a view showing a capillary tube disclosed in Japanese Patent Application Laid-Open No. 10-332228. As shown in FIG. 8, an insertion rod 12 that has been subjected to groove processing by a commercially available precision screw processing machine or the like is inserted into the outer tube 11. Since the crest 13 of the insertion rod 12 is in close contact with the inner surface of the outer pipe 11, a long spiral space 14 is formed between the outer pipe 11 and the insertion rod 12.
Are configured continuously. This spiral long space 14
By using as a decompressor, the length of the decompressor can be reduced as compared with the case where a capillary tube is used, and furthermore, a compact straight-tube depressurizer can be provided. Also, the same effect can be obtained by inserting an insertion rod that is not grooved into an outer tube having a groove formed on the inner surface.

FIG. 9 is a view showing a part of a decompression kit disclosed in Japanese Patent Application Laid-Open No. 10-205924. As shown in FIG. 9, the capillary tube 15 is spirally wound,
A cylindrical space is formed inside. By installing a filter, a check valve, and the like in a cylindrical space formed inside the capillary tube 15, the volume of the entire device can be reduced.

FIG. 10 is a diagram showing an elastically deformable capillary tube disclosed in Japanese Patent Application Laid-Open No. Hei 10-230070. In FIG. 10, the capillary tube 16
Since is made of an elastic material such as rubber or spring steel, it can be elastically deformed. This capillary tube 1
The critical flow rate of the refrigerant passing through the capillary tube 16 can be adjusted by adjusting the size of the bend of 6. When the external force on the capillary tube 16 is released, the capillary tube returns to the original shape by the elastic force.

FIG. 11 is a sectional view showing a capillary tube disclosed in Japanese Patent Application Laid-Open No. 10-220924.
In FIG. 11, the capillary tube 17 is made of copper, and a resin thin film layer 18 is provided on the inner surface. The formation of the resin thin film layer 18 can effectively prevent the impurities mixed in the refrigerant from adhering and prevent the chemical reaction between the inner surface of the capillary tube 17 and the impurities, so that the inner diameter of the capillary tube 17 is kept substantially constant. An excellent refrigeration, air conditioner, etc., which does not decrease in cooling capacity and is resistant to damage such as corrosion, can be obtained.

FIG. 12 is a view showing a capillary tube disclosed in Japanese Patent Application Laid-Open No. 10-318633. FIG.
In 2, the inner surface of the capillary tube 19 is coated with Teflon or the like having excellent releasability as a coating or a tube 20.
9 can be prevented from adhering to the sludge. Also,
Since the coating or tube 20 is replaceable, it can be repaired even if sludge adheres.

FIG. 13 is a view showing a capillary tube disclosed in Japanese Patent Application Laid-Open No. 10-238902. FIG.
In 3, the inner surface of the capillary tube 22 is
An uneven surface 23 of ２５25 mm is formed. Even if the sludge reaches and adheres to the capillary tube 22, the roughness on the inner surface does not change significantly, so that the flow path resistance on the inner surface of the capillary tube 22 does not increase, and the occurrence of problems due to a decrease in the refrigerant flow rate is prevented. Can be. Further, by manufacturing the capillary tube 22 with polytetrafluoroethylene, it is possible to prevent sludge from adhering to the capillary tube 22.

FIG. 14 is a view showing a capillary tube disclosed in Japanese Patent Application Laid-Open No. 8-200841. FIG.
By applying the Teflon coating material 25 to the inner surface of the capillary tube 24, the amount of sludge adhering to the capillary tube 24 can be reduced.

[0010]

The prior art described above has the following problems. In other words, the actual open 4-1
No. 2 (FIG. 7), JP-A-10-205924 (FIG. 9) and JP-A-10-230070 (FIG. 10).
In the conventional example shown in (1), since the expansion efficiency of the capillary tube is low, it is necessary to take measures such as extending the length of the capillary tube or using a plurality of capillary tubes. For this reason, there have been problems such as an increase in manufacturing cost and an increase in the volume of the device, and a problem such as a decrease in the flow rate of the refrigerant because sludge tends to adhere to the inner surface of the capillary tube.

JP-A-10-332228 (FIG. 8)
In the conventional example shown in (1), the insertion rod must be newly manufactured and the insertion rod or the outer pipe must be grooved, which increases the manufacturing cost and the total of the newly manufactured outer pipe and insertion rod. There is a problem that the weight becomes larger than when a capillary tube is used. In addition, since no measures have been taken to prevent the adhesion of sludge, problems such as a decrease in the flow rate of the refrigerant have occurred.

JP-A-10-220924 (FIG. 1)
1) In the conventional examples shown in JP-A-10-318633 (FIG. 12) and JP-A-8-200841 (FIG. 14), the expansion efficiency of the capillary tube is low, so that the length of the capillary tube is increased. Or, measures such as using a plurality of capillary tubes were necessary. For this reason, there have been problems in that the manufacturing cost cannot be reduced and the volume of the device increases.

JP-A-10-238902 (FIG. 1)
In the conventional example shown in 3), a large amount of sludge adheres to the inner surface of the capillary tube due to long-term operation of the equipment,
The capillary tube is blocked. In addition, when a capillary tube is made of polytetrafluoroethylene, the strength of the capillary tube is reduced, so it is necessary to take measures such as increasing the wall thickness of the capillary tube or attaching a reinforcing member, thereby increasing the manufacturing cost. The problem arose.

The present invention has been made to solve the above-mentioned problems in the prior art. That is, an object of the present invention is to reduce the length of the capillary tube by improving the expansion efficiency of the refrigerant in the capillary tube, and further to prevent sludge from adhering to the capillary tube to prevent a decrease in the refrigerant flow rate. And

[0015]

In order to achieve the above-mentioned object, the present invention takes the following technical means. That is, the present invention described in claim 1 comprises a condenser for condensing and liquefying a gaseous refrigerant, a capillary tube for squeezing the liquefied refrigerant and transferring it to an evaporator, and evaporating the liquefied refrigerant. In the refrigerating / air-conditioning apparatus comprising: an evaporator to be compressed; and a compressor for compressing the vaporized refrigerant and discharging the refrigerant to the condenser again, at least one convex portion is provided on the inner surface of the capillary tube. It is characterized by having.

The refrigeration / air-conditioning apparatus according to the present invention is characterized in that a film of a water-repellent material is formed on the inner surface of the capillary tube.

The refrigeration / air conditioning device according to the present invention described in claim 3 is characterized in that the refrigerant is hydrochlorofluorocarbon-based fluorocarbon or a substance mainly composed of hydrochlorofluorocarbon-based fluorocarbon.

The refrigeration / air conditioning apparatus according to the present invention described in claim 4 is characterized in that the refrigerant is hydrofluorocarbon-based chlorofluorocarbon or a substance mainly composed of hydrofluorocarbon-based chlorofluorocarbon.

The refrigeration / air-conditioning apparatus according to the present invention is characterized in that the refrigerant is a hydrocarbon or a substance mainly composed of hydrocarbons.

The refrigeration / air-conditioning apparatus according to the present invention is characterized in that the refrigerating machine oil of the refrigeration / air-conditioning apparatus is mineral oil, alkylbenzene oil or a mixture thereof.

The refrigeration / air-conditioning apparatus according to the present invention is characterized in that the refrigeration oil of the refrigeration / air-conditioning apparatus is an ester-based lubricant, an ether-based lubricant, or a mixture thereof. .

According to the present invention, there is provided a capillary tube for squeezing a refrigerant liquefied by a condenser and transferring the refrigerant to an evaporator during a refrigerant circulation cycle of a refrigeration / air conditioner. A method for producing a capillary tube, characterized in that a convex portion is formed on an inner surface of the tube by applying a pressing force to one place to plastically deform the tube.

According to a ninth aspect of the present invention, there is provided a capillary tube for squeezing refrigerant liquefied by a condenser and transferring the refrigerant to an evaporator during a refrigerant circulation cycle of a refrigeration / air conditioner. When forming a layer,
A method of manufacturing a capillary tube, comprising: forming a film with a surfactant on the inner surface of the capillary tube; and applying a water-repellent material on the film with the surfactant.

According to a tenth aspect of the present invention, in the method for manufacturing a capillary tube, the formation of the surfactant film on the inner surface of the capillary tube is performed by using the surfactant or a solution in which the surfactant is dissolved. The above-described formation is performed by immersing one end of the tube and sucking the tube from the other end.

According to the present invention, in the method for manufacturing a capillary tube, the application of the water-repellent material onto the surfactant film may be carried out by interfacing with the water-repellent material or a solution in which the material is dissolved. The coating is performed by immersing one end of the capillary tube on which the activator film is formed and sucking the capillary tube from the other end.

According to a twelfth aspect of the present invention, in the method for manufacturing a capillary tube, a step of applying a water-repellent material and further firing the same is provided.

According to a thirteenth aspect of the present invention, in the step of baking the water-repellent material, the baking is performed in an atmosphere replaced with an inert gas such as nitrogen.

[0028]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a first embodiment according to the present invention, and shows a sectional view in the axial direction of a capillary tube. Note that, other than the capillary tube shown in FIG. 1, a refrigeration cycle similar to the conventional technique shown in FIG. 7 is configured. In FIG.
26 is a capillary tube, and 27 is a projection provided on the capillary tube 26. In the present embodiment, the convex portion 27 is provided at one position, but a plurality of similar convex portions 27 may be provided. Also convex part 27
Can be manufactured by an easy method such as sandwiching a convex metal from the outside of the capillary tube 26 from both sides, for example, and can be manufactured at a relatively low cost. The convex portion 27 may press the entire outer peripheral surface of the tube 26, for example, like a roller process to form the convex portion 27 on the ring.

By providing the convex portion 27 on the capillary tube 26 as described above, since this portion functions as a throttle portion, the capillary tube 26 without the convex portion 27 is provided.
Therefore, the expansion efficiency of the refrigerant can be improved, and the length of the capillary tube 26 can be reduced. Further, by providing the convex portions 27 of the capillary tube 26 at a plurality of positions, the expansion efficiency of the refrigerant is further improved, and the length of the capillary tube 26 can be further reduced.

FIG. 1 shows a second embodiment according to the present invention.
The capillary tube 26 constructed as described above is used for refrigeration using a hydrochlorofluorocarbon-based chlorofluorocarbon or a substance mainly composed of hydrochlorofluorocarbon-based chlorofluorocarbon as a refrigerant and a mineral oil, an alkylbenzene oil or a mixture thereof as a refrigerator oil. This is to be applied to air conditioners. As a result, the expansion efficiency of the refrigerant can be improved and the length of the capillary tube 26 can be reduced, and the expansion efficiency can be further improved and the length of the tube 26 can be further reduced by providing the plurality of protrusions 27, as in the previous embodiment. .

A third embodiment according to the present invention is shown in FIG.
Is used as a refrigerant for a material mainly composed of hydrofluorocarbon-based chlorofluorocarbon or hydrofluorocarbon-based chlorofluorocarbon as a refrigerant, and a refrigerating machine or an air-conditioning system in which a substance that is a mineral oil, an alkylbenzene oil or a mixture thereof is used as a refrigerating machine oil. Is to apply.
As a result, the expansion efficiency of the refrigerant can be improved and the length of the capillary tube 26 can be reduced as in the previous embodiment, and the expansion efficiency can be further improved by providing a plurality of convex portions 27 to further reduce the length of the tube 26. it can.

A fourth embodiment according to the present invention is shown in FIG.
Refrigeration using the capillary tube 26 configured as described above as a refrigerant using a hydrofluorocarbon-based chlorofluorocarbon or a substance mainly composed of hydrofluorocarbon-based chlorofluorocarbon as a refrigerant, and a substance that is an ester-based lubricating oil, an ether-based lubricating oil or a mixture thereof as a refrigerating machine oil. To be applied to an air conditioner. As a result, the expansion efficiency of the refrigerant can be improved and the length of the capillary tube 26 can be reduced as in the previous embodiment, and the expansion efficiency can be further improved by providing a plurality of convex portions 27 to further reduce the length of the tube 26. it can.

A fifth embodiment according to the present invention will be described with reference to FIG.
A hydrocarbon tube or a substance mainly composed of hydrocarbons is used as a refrigerant for the capillary tube 26 configured as described above, and mineral oil,
The present invention is applied to a refrigerating or air-conditioning apparatus in which a substance which is an alkylbenzene oil or a mixture thereof is used as a refrigerator oil. As a result, the expansion efficiency of the refrigerant can be improved and the length of the capillary tube 26 can be reduced as in the previous embodiment, and the expansion efficiency can be further improved by providing a plurality of convex portions 27 to further reduce the length of the tube 26. it can.

FIG. 2 is a view showing a sixth embodiment according to the present invention, and shows a cross section of the capillary tube 28 in the axial direction. A refrigeration cycle similar to that of the conventional example shown in FIG. 7 is configured except for the capillary tube 28 shown in FIG. In FIG. 2, reference numeral 28 denotes a capillary tube, reference numeral 29 denotes a projection provided on the tube 28, and reference numeral 30 denotes a film of a water-repellent material applied to the inner surface of the tube 28. Examples of the water-repellent material include, but are not limited to, fluorine-based resins. In this embodiment, the convex portion 29 is provided at one place, but a plurality of convex portions 29 may be provided.

By using such a capillary tube 28 for a refrigeration / air conditioner, the film of the water-repellent material can prevent sludge from adhering in the capillary tube 28, thereby avoiding a decrease in refrigerant circulation efficiency. be able to. At the same time, the convex portion 29 is provided on the inner surface of the capillary tube 28 as in the previous embodiment, so that the expansion efficiency of the refrigerant can be improved, the length of the capillary tube 28 can be reduced, and a plurality of By providing the convex portion 29, the expansion efficiency is further improved, and the length of the capillary tube 28 can be further reduced.

A seventh embodiment according to the present invention is similar to that of FIG.
Refrigeration and air conditioning using a capillary tube 28 configured as described above as a refrigerant using a substance mainly composed of hydrochlorofluorocarbon-based chlorofluorocarbon or hydrochlorofluorocarbon-based chlorofluorocarbon as a refrigerant oil and a substance that is a mineral oil, an alkylbenzene oil or a mixture thereof. The present invention is applied to devices. This can prevent sludge from adhering to the inner surface of the capillary tube, improve the expansion efficiency of the refrigerant as in the previous embodiment, shorten the length of the capillary tube 28, and provide a plurality of convex portions 29. As a result, the expansion efficiency is further improved, and the length of the capillary tube 28 can be further reduced.

An eighth embodiment according to the present invention will be described with reference to FIG.
In a refrigeration and air-conditioning system in which a capillary tube 28 configured as described above is used as a refrigerant, a substance mainly composed of hydrofluorocarbon-based fluorocarbon or hydrofluorocarbon-based fluorocarbon is used as a refrigerant, and a substance that is a mineral oil, an alkylbenzene oil or a mixture thereof is used as a refrigerating machine oil. Is to apply.
This can prevent the sludge from adhering to the inner surface of the capillary tube, improve the expansion efficiency of the refrigerant, shorten the length of the capillary tube 28, and further increase the expansion efficiency by providing the plurality of convex portions 29. Thus, the length of the capillary tube 28 can be further reduced.

A ninth embodiment according to the present invention will be described with reference to FIG.
Refrigeration using the capillary tube 28 configured as described above as a refrigerant using hydrofluorocarbon-based fluorocarbon or a substance mainly composed of hydrofluorocarbon-based fluorocarbon as a refrigerant, and a substance that is an ester-based lubricating oil, an ether-based lubricating oil, or a mixture thereof as a refrigerating machine oil. To be applied to an air conditioner. This prevents sludge from adhering to the inner surface of the capillary tube, improves the expansion efficiency, shortens the length of the capillary tube 28, and further improves the expansion efficiency by providing the plurality of convex portions 29. The length of the tube 28 can be further reduced.

In a tenth embodiment of the present invention, a capillary tube 28 constructed as shown in FIG. 2 is made of a hydrocarbon or a substance mainly composed of hydrocarbons as a refrigerant, a mineral oil, an alkylbenzene oil or a mixture thereof. The present invention is applied to a refrigeration and air-conditioning system using a substance as a refrigeration oil. This prevents sludge from adhering to the inner surface of the capillary tube, improves the expansion efficiency, shortens the length of the capillary tube 28, and further improves the expansion efficiency by providing the plurality of convex portions 29. The length of the capillary tube 28 can be further reduced.

FIGS. 3 to 6 show an eleventh embodiment according to the present invention, and show a method of forming a film of a water-repellent material on the inner surface of a capillary tube. 3 to 6, 28 is a capillary tube, 29 is a convex portion, 30 is a film of a water-repellent material, 31 is a film of a surfactant, 32 is a liquid of a surfactant or a liquid in which a surfactant is dissolved. And 34 are liquids of a water-repellent material or liquids in which the water-repellent material is dissolved.

As shown in FIG. 3, the capillary tube 2
A surfactant is applied to the inner surface of 8 and dried to form a film 31 of the surfactant. The method of applying the surfactant is, for example, as shown in FIG.
8 can be performed by immersing one end of the liquid in a surfactant liquid or a liquid 32 in which a surfactant is dissolved, and suctioning the other end in the direction of arrow 33. Examples of the surfactant used include, but are not limited to, stearic acid-based and oleic acid-based surfactants.

After the coating 31 of the surfactant is formed on the inner surface of the capillary tube 28, as shown in FIG.
A water repellent material is applied and dried to form a film 30 of the water repellent material. By forming the coating 31 of a surfactant having a low surface tension in advance, the water-repellent material film 30 can be formed uniformly on the inner surface of the capillary tube 28. As a method of applying the water-repellent material, for example, as shown in FIG. 6, one end of the capillary tube 28 is immersed in a liquid of the water-repellent material or a liquid 34 in which the water-repellent material is dissolved, and is suctioned in the direction of arrow 35 from the other end. Can be performed.

In the twelfth embodiment of the present invention, when the water-repellent material film 30 shown in FIG. 5 is formed of a material which needs to be fired, such as a fluorine resin, the water-repellent material is applied. After drying, firing is performed. In the case of these water repellent materials, a strong coating 30 can be formed by firing. When the capillary tube 28 is formed of a material that is easily oxidized, the atmosphere 30 is replaced with an inert gas such as nitrogen, and then fired, whereby the film 30 of the water-repellent material can be formed.

The method of manufacturing the capillary tube 28 having the water-repellent material film formed on the inner surface thereof described with reference to FIGS.
Although 9 is provided, it is of course possible to apply to a capillary tube having no projection.

[0045]

According to the present invention, since at least one convex portion is provided on the inner surface of the capillary tube, the expansion efficiency of the refrigerant is improved as compared with the conventional capillary tube, whereby the total length of the capillary tube can be shortened. .
The projection formed on the inner surface of the capillary tube can be easily formed by plastically deforming the capillary tube from the outside.

In the present invention relating to forming a film of a water-repellent material on the inner surface of a capillary tube having at least one convex portion on the inner surface, the expansion efficiency of the refrigerant can be improved and the sludge to the capillary tube can be improved. Can be greatly reduced, and a decrease in the flow rate of the refrigerant can be prevented.

Further, in the present invention relating to forming a film of a surfactant on the inner surface of the capillary tube and applying a water repellent material on the film of the surfactant to form a film of the water repellent material, A film of a water-repellent material can be formed, and the above effect can be obtained more reliably.

Further, the present invention relates to forming a film of a surfactant on the inner surface of a capillary tube, applying a water-repellent material on the film of the surfactant to form a film of the water-repellent material, and firing. Thus, a uniform and strong water-repellent material film can be formed, and the above effects can be more reliably obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a capillary tube according to the present invention.

FIG. 2 is a sectional view showing another embodiment of the capillary tube according to the present invention.

FIG. 3 is a cross-sectional view showing a manufacturing process of another embodiment of the capillary tube according to the present invention.

FIG. 4 is an explanatory view showing a method for manufacturing a capillary tube according to the present invention.

FIG. 5 is a sectional view showing another embodiment of the capillary tube according to the present invention.

FIG. 6 is an explanatory view showing another method of manufacturing the capillary tube according to the present invention.

FIG. 7 is a refrigerant circuit diagram showing a refrigeration cycle according to the related art.

FIG. 8 is a partial cross-sectional view showing an example of a conventional capillary tube.

FIG. 9 is a schematic view showing a part of a decompression kit according to the prior art.

FIG. 10 is a schematic view showing another example of a conventional capillary tube.

FIG. 11 is a cross-sectional view showing another example of a conventional capillary tube.

FIG. 12 is an external view showing another example of a conventional capillary tube.

FIG. 13 is a cross-sectional view showing another example of a conventional capillary tube.

FIG. 14 is a cross-sectional view showing another example of a conventional capillary tube.

[Explanation of symbols]

1: compressor, 2: outdoor heat exchanger (condenser), 3: capillary tube, 4: indoor heat exchanger (evaporator),
26: Capillary tube, 27: Convex part, 28: Capillary tube, 29: Convex part, 30: Film of water-repellent material, 31: Coating with surfactant, 32: Liquid containing surfactant or the same, 33 : Water repellent material or liquid in which the material is dissolved.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shinji Nakajima 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsui Electric Co., Ltd. (72) Inventor Noboru Masuda 2-3-2 Marunouchi 3-chome, Chiyoda-ku, Tokyo Rishi Electric Co., Ltd. (72) Inventor Shin Sekiya 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsui Electric Co., Ltd. (72) Inventor Kosuke Makino 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Inside Electric Co., Ltd. (72) Inventor Takanori Omori 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsui Electric Co., Ltd. (72) Inventor Tetsuzo Matsuki 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Inside the corporation

Claims (13)

[Claims] A condenser for condensing and liquefying a gaseous refrigerant; a capillary tube for squeezing the liquefied refrigerant and transferring it to an evaporator; an evaporator for evaporating the liquefied refrigerant; A compressor that compresses a vaporized refrigerant and discharges the refrigerant to a condenser again, wherein at least one projection is provided on an inner surface of the capillary tube. Air conditioner. 2. A film made of a water-repellent material is formed on an inner surface of the capillary tube.
Refrigeration / air conditioning equipment. 3. The method according to claim 2, wherein the refrigerant is hydrochlorofluorocarbon-based fluorocarbon or a substance mainly composed of hydrochlorofluorocarbon-based fluorocarbon.
A refrigeration / air conditioning device according to claim 1. 4. The refrigeration / air-conditioning apparatus according to claim 1, wherein the refrigerant is hydrofluorocarbon-based fluorocarbon or a substance mainly composed of hydrofluorocarbon-based fluorocarbon. 5. The refrigeration / air-conditioning apparatus according to claim 1, wherein the refrigerant is a hydrocarbon or a substance mainly composed of a hydrocarbon. 6. The refrigeration / air-conditioning apparatus according to claim 3, wherein the refrigerating machine oil of the refrigeration / air-conditioning apparatus is mineral oil, alkylbenzene oil, or a mixture thereof. 7. The refrigeration / air-conditioning apparatus according to claim 4, wherein the refrigerating machine oil of the refrigeration / air-conditioning apparatus is an ester-based lubricant, an ether-based lubricant, or a mixture thereof. 8. A capillary tube for condensing a refrigerant liquefied by a condenser of a refrigeration / air-conditioning device and transferring it to an evaporator, by applying a pressing force to at least one portion of an outer peripheral portion of the capillary tube to plastically deform the tube. And forming a convex portion on the inner surface of the tube. 9. A capillary tube for squeezing a refrigerant liquefied by a condenser of a refrigeration / air-conditioning device and transferring the liquefied refrigerant to an evaporator, wherein a film of a surfactant is formed on the inner surface of the capillary tube, and the film of the surfactant is formed. Forming a film made of a water-repellent material on the inner surface by applying a water-repellent material on the surface of the capillary tube. 10. In forming a surfactant film on the inner surface of the capillary tube, one end of the capillary tube is immersed in the surfactant or a solution in which the surfactant is dissolved, and the film is formed by suction from the other end. The method according to claim 9, wherein: 11. When applying a water-repellent material on the surfactant film, one end of the capillary tube on which the surfactant film is formed is immersed in the water-repellent material or a solution in which the water-repellent material is dissolved. The method according to claim 9, wherein the application is performed by suction from an end. 12. The method according to claim 9, further comprising a step of applying a water-repellent material and then firing the same after applying the water-repellent material. 13. The method according to claim 12, wherein, in the step of baking the water-repellent material, the baking is performed in an atmosphere replaced with an inert gas such as nitrogen.