JP2000039235A - Freezing unit for freezing refrigerator and production therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a cooling performance from being lowered due to the decomposition of a refrigerant in the freezing unit of a freezing refrigerator. SOLUTION: A freezing unit of a freezing refrigerator comprises a compressor 2 for compressing a gaseous refrigerant to prescribed condensing pressure, a condenser 3 for condensing the refrigerant compressed by the compressor 2, a dehumidifier 4, for removing water included in the refrigerant condensed by the condenser 3, a fine tube for reducing the pressure of the refrigerant dehumidified by the dehumidifier 4 and an evaporator 6 for evaporating the refrigerant whose pressure is reduced by the fine tube 5. The dehumidifier 4 employs a dehumidifying agent composed of silica gel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration unit mainly used for a refrigerator for home use.

[0002]

2. Description of the Related Art Generally, a refrigeration unit of a refrigerator-freezer is provided with a dehumidifier for removing moisture in the refrigerant. This is because the inside diameter of 0.6 to 0.6
0.8mm thin tube (hereinafter referred to as capillary tube)
Is set to about −20 ° C., thereby preventing the water contained in the refrigerant from becoming ice and clogging the capillary tube to cause poor cooling. Conventionally, as a dehumidifier of this dehumidifier, a synthetic zeolite excellent in moisture adsorption has been often used.

[0003]

However, although synthetic zeolite has excellent water adsorption properties, it has high reactivity with the refrigerant, decomposes the refrigerant, and the molecules of the decomposed refrigerant degrade the oil of the compressor. As a result, there is a problem that the life of the refrigeration unit is shortened.

[0004] The reaction process between the synthetic zeolite and the refrigerant will be described in detail below. Generally, synthetic zeolites have a large number of pores of uniform diameter. Water has a molecular diameter of 2.8 angstroms, refrigerant CFC-12 (CF ₂ Cl ₂ ) has a molecular diameter of 5.2 angstroms, and refrigerant HFC-134a (CH ₂ FCF).
The molecular diameter of ₃ ) is about 4.3 angstroms, and the molecular diameter of water is smaller than the molecular diameter of the refrigerant. Therefore, it is possible to adsorb only water molecules by selecting a synthetic zeolite having an appropriate pore diameter. it can.

[0005] By the way, it has been confirmed by experiments that synthetic zeolite has a high chemical activity, and when a refrigerant is adsorbed to pores for some reason, the refrigerant decomposes at a relatively low temperature. Table 1 shows the decomposition rate of the refrigerant when the synthetic zeolite, the refrigerant, and the oil of the compressor are sealed in a tube and left at a temperature of 65 ° C. for 30 days, when the refrigerant is adsorbed on the synthetic zeolite, and when the refrigerant is not adsorbed. 3 shows the results of comparison with respect to.

[0006]

[Table 1]

As described above, when the refrigerant is adsorbed on the synthetic zeolite, the decomposition rate of the refrigerant rapidly increases. The reason why the refrigerant is adsorbed on the synthetic zeolite will be described. For example, refrigerant HFC-134a (molecular diameter: 4.3 angstroms)
The pore size of the synthetic zeolite is 3 Å. However, the pore diameter of the synthetic zeolite increases as the temperature increases. At the refrigerant discharge part of the compressor of the refrigeration unit, the refrigerant is rapidly compressed.
When the synthetic zeolite is finely divided and flows into the refrigerant discharge portion of the compressor, the refrigerant may be adsorbed. It is to be noted that the granulation of the synthetic zeolite is caused by particles of the synthetic zeolite mutually rubbing due to pulsation of a refrigerant flow, vibration transmitted from a compressor, or the like.

[0008] Since the decomposition rate of the refrigerant varies depending on the type of compressor oil, the refrigerant is decomposed at the refrigerant discharge portion of the compressor depending on the combination with the compressor oil. When the refrigerant HFC-134a is decomposed, HFC-32 (C
H ₂ F ₂ ) has been confirmed to occur, and HFC-3
Since the molecular diameter of No. 2 is as small as 3.2 angstroms, it is adsorbed by the synthetic zeolite and further decomposes, thereby deteriorating the cooling performance.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to prevent a refrigerant in a refrigerating unit of a refrigerating refrigerator from being decomposed to lower the cooling performance.

[0010]

In order to achieve the above-mentioned object, the present invention provides a compressor for compressing a gaseous refrigerant to a predetermined condensing pressure, and a compressor for compressing the refrigerant compressed by the compressor. A condenser that condenses, a dehumidifier that removes moisture contained in the refrigerant condensed by the condenser, a thin tube that decompresses the refrigerant dehumidified by the dehumidifier, and an evaporator that evaporates the refrigerant depressurized by the thin tube. , Wherein the dehumidifier uses a dehumidifier made of silica gel.

The invention according to claim 2 is the refrigeration unit according to claim 1, wherein the refrigerant is HFC-134a.

The invention of claim 3 provides a compressor for compressing a gaseous refrigerant to a predetermined condensing pressure, a condenser for condensing the refrigerant compressed by the compressor, and a refrigerant condensed by the condenser. A refrigerator comprising a refrigeration unit including a thin tube for reducing pressure and an evaporator for evaporating the refrigerant decompressed in the thin tube, wherein the refrigeration unit is provided with a dehumidifier before performing an operation for performance confirmation. After the connection, the operation is performed, and the moisture contained in the refrigerant circulating in the refrigeration unit is removed by the dehumidifier, the dehumidifier is removed and the refrigeration unit is hermetically sealed.

The invention according to claim 4 is the method according to claim 3, wherein the refrigerant is HFC-134a.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a conceptual diagram of a refrigeration unit 1 according to a first embodiment of the present invention, FIG. 2 is a perspective view showing an arrangement state of the refrigeration unit 1 in a refrigerator, and FIG. . The arrows in the figure indicate the flow direction of the refrigerant.

The refrigeration unit 1 shown in FIGS. 1 and 2 is built in a refrigerator-freezer used in ordinary households.
It includes a compressor 2, a condenser 3, a dehumidifier 4, a capillary tube 5, and an evaporator 6.

The compressor 2 is arranged at the bottom of a refrigerator or the like and compresses a gaseous refrigerant to a predetermined condensing pressure.

The condenser 3 is disposed on the side or bottom of the refrigerator, and the refrigerant compressed by the compressor 2 is condensed by radiating heat there.

As shown in FIG. 3, the dehumidifying device 4 is provided with a tubular case 7 having both ends opened, a partition plate 8 arranged on one end of the case 7, and an other end of the case 7. The case 7 includes a filter 9 and a dehumidifying agent (silica gel) 10 filled in the case 7 by a partition plate 8. The end on the partition plate 8 side of the case 7 is connected to the condenser 3, and the end on the filter 9 side is connected to the capillary tube 5. The moisture contained in the refrigerant condensed in the condenser 3 is removed by the dehumidifier 10 when passing through the case 7.

The capillary tube 5 reduces the pressure of the liquid refrigerant dehumidified by the dehumidifier 4 so that the liquid refrigerant can be evaporated by the evaporator 6 and adjusts the flow rate of the refrigerant.

The evaporator 6 cools the surrounding air and evaporates the refrigerant by heat exchange between the surrounding air and the internal refrigerant. The gasified refrigerant is supplied to the compressor 2 through the pipe 11.

Table 2 shows experimental data comparing the reactivity of the synthetic zeolite and silica gel with respect to the refrigerant. The synthetic zeolite and silica gel were sealed in separate tubes together with the refrigerant and the oil of the compressor.
It shows the decomposition rate of the refrigerant after being left for 0 days.

[0022]

[Table 2]

As shown in Table 2, the reactivity of the silica gel to the refrigerant is low, and even if silica gel is finely divided into the refrigerant discharge portion of the compressor 2 for some reason, the refrigerant generated by the high temperature of the refrigerant discharge portion (The degree of decomposition is small and this alone does not cause deterioration of the refrigeration performance), and does not proceed any further. Therefore, deterioration of the refrigeration performance can be prevented.

Next, a second embodiment of the present invention will be described. Generally, a freezing unit of a freezer-refrigerator has a hermetic structure, and if moisture in the refrigerant unit is removed at the time of manufacturing the freezer-refrigerator, moisture does not subsequently enter the freezing unit. Also, during the production of refrigerators and refrigerators,
Usually, in the final step, the refrigerant is charged into the refrigeration unit, and the operation for confirming the performance is performed for about 20 minutes.

Therefore, in the present embodiment, a dehumidifier is connected to the refrigeration unit immediately before the final step, and the dehumidifier is operated during operation for performance confirmation. As the refrigerant flows through the refrigeration unit, the water in each part of the refrigeration unit is carried by the refrigerant and removed by the dehumidifier. When the operation is completed, the dehumidifier is removed and the refrigeration unit is sealed.

This eliminates the need to provide a dehumidifier in the refrigeration unit, reduces the number of components, and completely eliminates the promotion of refrigerant decomposition, thereby extending the life of the refrigerator.

[0027]

As described above, in the refrigeration unit of the present invention, decomposition of the refrigerant is promoted by using silica gel which is less than 30 times more reactive than synthetic zeolite as a dehumidifier of the dehumidifier. Therefore, it is possible to prevent the cooling performance from lowering.

Further, according to the method of manufacturing the refrigerator of the present invention, the dehumidifier is connected to the refrigeration unit before the operation for performance confirmation, and the operation for performance confirmation is performed to circulate through the refrigeration unit. After removing the moisture contained in the refrigerant by the dehumidifier, the dehumidifier is removed and the refrigeration unit is hermetically sealed, so that the number of parts is reduced and the decomposition of the refrigerant is not promoted, and the cooling is performed. The performance can be prevented from deteriorating.

It should be noted that the present invention, particularly,
-32 (CH ₂ F ₂ ) -generated refrigerant HFC-134a
Suitable for refrigeration units using (CH ₂ FCF ₃ ).

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a refrigeration unit 1 according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing an arrangement state of the refrigeration unit 1 in the refrigerator.

FIG. 3 is a center line cross-sectional view of the dehumidifying device 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Refrigeration unit 2 Compressor 3 Condenser 4 Dehumidifier 5 Capillary tube (capillary tube) 6 Evaporator 7 Case 8 Partition plate 9 Filter 10 Dehumidifier

Claims (4)

[Claims] 1. A compressor for compressing a gaseous refrigerant to a predetermined condensing pressure, a condenser for condensing the refrigerant compressed by the compressor, and removing water contained in the refrigerant condensed by the condenser. A dehumidifier, a thin tube for depressurizing the refrigerant dehumidified by the dehumidifier, and an evaporator for evaporating the refrigerant depressurized by the thin tube, wherein the dehumidifier is a dehumidifier made of silica gel. A refrigerating unit for a refrigerator-freezer, characterized by using an agent. 2. The refrigeration unit of a refrigerator according to claim 1, wherein the refrigerant is HFC-134a. 3. A compressor for compressing a gaseous refrigerant to a predetermined condensing pressure, a condenser for condensing the refrigerant compressed by the compressor, a thin tube for decompressing the refrigerant condensed in the condenser, A method for manufacturing a refrigerator including a refrigerating unit including an evaporator for evaporating a refrigerant depressurized by a thin tube, wherein a dehumidifier is connected to the refrigerating unit before performing an operation for performance confirmation, and the operation is performed. After removing the water contained in the refrigerant circulating in the refrigeration unit by the dehumidifier,
A method for producing a refrigerator-freezer, comprising removing the dehumidifier and sealing the refrigeration unit. 4. The method according to claim 3, wherein the refrigerant is HFC-134a.