JPH06273003A - Refrigerating system - Google Patents

Abstract

PURPOSE:To prevent possible increase in input as caused by a drop in the refrigerating capacity and difficulty in compression attributed to a choking phenomenon in the capillary by preparing a second filter filled with a carbon dioxide adsorbent in addition to a first filter filled with a drying agent to remove carbon dioxide in a refrigerant. CONSTITUTION:A second filter formed right after a compressor discharge part 13 has a carbon dioxide adsorbent almost at the center thereof with a punched metal or a mesh. A refrigerant compressed with a machine section 12 is forced to be discharged to the compressor discharge part 13 as in a state of a gas phase by a compression heat or the like then generated. The discharged refrigerant passes through the second filter where it contact the carbon dioxide adsorbent comprising synthetic zeolite to remove carbon dioxide. Thus as the refrigerant contains no carbon dioxide, there is no phenomenon such as capillary chocking thereby eliminating the lowering of the refrigerating capacity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration system used in refrigerators, freezers, car air conditioners and the like.

[0002]

2. Description of the Related Art In recent years, chlorofluorocarbons (hereinafter C
Environmental problems such as ozone depletion and global warming due to the influence of FC) are drawing attention. From such a point of view, reducing the amount of CFC used as a refrigerant has become an extremely important theme. Conventionally, the completely halogenated carbon compounds that have been used as CFCs contain at least 1 hydrogen.
Substitution of halogenated carbon compounds containing more than one is being sought. More specifically, dichlorodifluoromethane (hereinafter referred to as CFC-12), which is a typical refrigerant, is C
It is a substitute for FC and is a halogenated carbon compound containing two hydrogens, which has little effect on ozone destruction 1,1,
1,2-Tetrafluoroethane (hereinafter HFC-134a
(Hereinafter referred to as ")", various improvements are being made.

For example, DuPo issued in October 1978
According to Research Disclosure by nt, HFC-134a is poorly compatible with any conventional oil and causes two-layer separation in all temperature ranges, and is soluble only in glycol-based oil. However, subsequent studies have revealed that it also dissolves in ester oils. For example, in U.S. Pat. No. 4,851,144, a refrigerating machine oil in which an ester type and a glycol type are mixed is used as a refrigerant HFC-1.
It has been shown to dissolve in 34a.

In recent studies, even ester-based oils alone have been found to be soluble in HFC-134a, and their application studies have been promoted. For example, Pudue CF
CConferane Proceedings p1 held in July 1990
90-195. Further, in order to improve the hydrolysis characteristic which was a problem with the ester type oil, a new type of carbonate type oil having a carbonate structure in which only carbon dioxide is generated even when hydrolyzed is proposed. Is being done. Next, an outline of a conventional refrigerator refrigeration system will be described with reference to FIG. As a refrigeration system, JP-A-60-235974
Issue and Mitsubishi Electric Technical Report Vol 58. No5. An example with a solenoid valve used in a refrigerator, a freezer or the like among the general refrigeration systems described in p33 to 36 and the like will be described.

Reference numeral 10 is a refrigeration system. Reference numeral 11 is a compressor, and 12 is a mechanical portion located inside the compressor 11. Reference numeral 13 is a compressor discharge portion, and 14 is a condenser.
A first filter 15 has a desiccant 16 fixed therein.

Reference numeral 17 is a solenoid valve using a solenoid, and 18 is a capillary tube. 19 is an evaporator and 20 is an accumulator. Reference numeral 21 is a suction line, and 22 is a check valve. Reference numeral 23 is a compressor suction part.

These refrigeration elements are connected to each other and sealed by copper or aluminum pipes, and a refrigerant 24 is sealed therein.

The operation of the refrigeration system configured as described above will be described below. The refrigerant 24 compressed by the mechanical section 12 is discharged to the compressor discharge section 13 in a gas phase state due to the compression heat generated at that time. The discharged refrigerant 24 releases heat in the condenser 14, gradually becomes a gas-liquid mixed state, and is finally liquefied.

The desiccant 16 fixed inside the first filter 15 removes water. This water-free refrigerant is a solenoid valve that opens in synchronization with compressor operation 1
6 and the capillary 17 while being depressurized. The depressurized refrigerant 24 expands in the evaporator 18 and removes heat from the surroundings. Then, the refrigerant 24 that has absorbed the heat enters a gas phase state, passes through the accumulator 20, the suction line 21, the check valve 22, and the compressor suction portion 23, and returns to the compressor 11.

[0010]

In the refrigeration system configured as described above, the compressed refrigerant is liquefied by the condenser, dehydrated by the desiccant in the dryer, and then vaporized and cooled by the evaporator. After doing, it returns to the compressor again. As the desiccant, a synthetic zeolite having a molecular diameter of 0.3 to 0.4 nm is usually used. Since this synthetic zeolite selectively adsorbs molecules according to its crystal diameter, it is difficult to adsorb substances other than substances having a molecular diameter (0.28 nm) of about water.

Furthermore, if HFC-134a is used as a refrigerant and carbonate oil is used as a refrigerating machine oil in the refrigeration system as described above, the following problems occur. That is, dehydration with a desiccant installed after the condenser was effective for the refrigerant, but had little effect on the refrigerating machine oil in the compressor. In particular, when the refrigerating machine oil is a carbonate type oil having high hydrophilicity, the tendency becomes large.

Further, since the compressor as shown in the figure tends to be miniaturized for the purpose of space saving in recent years, heat dissipation is deteriorated and it is often used at high temperature. For this reason, it is generally a card that does not generate acid even when decomposed.
Bonnet oil is about to be used. However, even in carbonate oil, when air and impurities coexist, a high temperature causes a chemical reaction to generate a substance harmful to the refrigeration system. Particularly, the carbonate type oil is hydrolyzed by the water remaining in the refrigerating machine oil to generate carbon dioxide. Further, the carbonate-based oil having a carbonate structure directly generates carbon dioxide instead of generating acid. And since this carbon dioxide has a low condensing temperature, it does not easily liquefy, and when it circulates in the refrigeration system, it becomes carbon dioxide, which reduces the refrigerating capacity by the choke phenomenon in the capillary,
There is a problem that the input is increased because it is difficult to compress.

Therefore, in the present invention, in view of the above points, a refrigerating machine oil which is composed of a halogenated carbon compound substituted with at least one or more hydrogen and a refrigerating machine oil which is dissolved in the refrigerant and decomposes to generate carbon dioxide is obtained. It is intended to provide a refrigeration system that can be used.

[0014]

In order to solve the above-mentioned problems, the refrigeration system of the present invention encloses a refrigerant composed of at least one halogenated carbon compound substituted with hydrogen and refrigerating machine oil dissolved in the refrigerant. And a condenser connected to the compressor, an evaporator, a first filter filled with a desiccant, and a second filter filled with a carbon dioxide adsorbent.

Further, in order to remove the non-condensable gas component in the refrigerant, this second filter is provided between the compressor discharge section in which the refrigerant is in the gas-liquid mixed phase state and the first filter. is there.

Further, a second filter is provided between the evaporator and the compressor suction part.

[0017]

According to the present invention, the carbon dioxide in the refrigerant is removed by the above-mentioned constitution by providing the second filter filled with the carbon dioxide adsorbent such as carbon dioxide in addition to the first filter filled with the desiccant. However, the choking phenomenon in the capillaries does not reduce the refrigerating capacity, and the compression does not easily increase the input.

Further, the second filter is provided between the compressor discharge section in which the refrigerant is in a gas-liquid mixed phase and the first filter, or between the evaporator and the compressor suction section. The carbon dioxide can be efficiently removed without being affected by the refrigerant.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A refrigeration system according to embodiments of the present invention will be described below with reference to the drawings. The same components as those of the conventional example are designated by the same reference numerals and the description thereof will be omitted.

FIG. 1 shows a block diagram of a refrigerating system in an embodiment of the present invention. In FIG. 1, 1 is a second filter formed immediately after the compressor discharge part 12, and 2 is a carbon dioxide adsorbent fixed in the approximate center of the second filter by punch metal or mesh. Is. As a carbon dioxide adsorbent, since the gas in question in this case is carbon dioxide, the crystal diameter having a large carbon dioxide adsorption effect is usually 1 n even in the presence of water.
m synthetic zeolite is preferred. Specifically, it has high heat resistance,
Molecular Sieves 13X (manufactured by Union Carbide), which has high carbon dioxide adsorption power even at high temperatures, is suitable.

The operation of the refrigeration system configured as described above will be described. The refrigerant 24 compressed by the mechanical section 12 is discharged to the compressor discharge section 13 in a gas phase state due to the compression heat generated at that time. The discharged refrigerant 24 passes through the second filter 1, and at that time, comes into contact with the carbon dioxide adsorbent 2 made of synthetic zeolite to remove carbon dioxide.

Particularly, the carbon dioxide adsorbent 2 is fixed at the approximate center of the second filter 1. Therefore, the partially liquefied refrigerant 24 does not come into contact with the carbon dioxide adsorbent because it flows through the tube wall of the second filter 1. That is, carbon dioxide in the vapor phase of the refrigerant 24 can be preferentially adsorbed. The refrigerant 24 from which carbon dioxide has been removed does not contain carbon dioxide, which is carbon dioxide, and thus easily releases heat in the condenser 14 to be liquefied.

The desiccant 16 fixed inside the first filter 15 removes water. This water-free refrigerant is a solenoid valve that opens in synchronization with compressor operation 1
7 and the capillary 18 while being depressurized. At this time, since the refrigerant 24 does not contain carbon dioxide, which is carbon dioxide, a phenomenon like a capillary choke does not occur and the refrigerating capacity does not deteriorate.

The depressurized refrigerant 24 is supplied to the evaporator 19
It expands and takes heat from the surroundings. Then, the refrigerant 24 that has absorbed the heat enters a gas phase state, passes through the accumulator 20, the suction line 21, the check valve 22, and the compressor suction portion 23, and returns to the compressor 11. Since the refrigerant 24 returned to the compressor does not contain carbon dioxide, which is carbon dioxide, it is easily compressed and the input does not increase.

As described above, according to this embodiment, the refrigerant 24
The second filter 1 for removing the non-condensed gas component in the inside is provided between the compressor discharge part 13 and the first filter 15, so that carbon dioxide is removed from the gas phase in a high pressure state. Therefore, adsorption can be performed quickly.

Another embodiment of the present invention will be described below with reference to the drawings. FIG. 2 shows a block diagram of a refrigeration system in another embodiment of the present invention. In FIG. 2, 3 is a second filter formed in the suction line 21 between the accumulator 20 and the check valve 22,
Reference numeral 4 is a carbon dioxide adsorbent fixed therein by punch metal or mesh.

The operation of the refrigeration system configured as described above will be described. The refrigerant 24 compressed by the mechanical section 12 is discharged to the compressor discharge section 13 in a gas phase state due to the compression heat generated at that time. The discharged refrigerant 24 releases heat in the condenser 14 and gradually liquefies.

Then, the moisture is removed by the desiccant 16 fixed inside the first filter 15. The refrigerant from which the water has been removed passes through the solenoid valve 17 that opens in synchronization with the operation of the compressor 11, and passes through the capillary 18 while being depressurized. The depressurized refrigerant 24 expands in the evaporator 19 and takes heat from the surroundings.

Then, the refrigerant 24 that has absorbed the heat becomes a gas phase state, the refrigerant 24 in the liquid phase state is removed by the accumulator 20, passes through the second filter 3, and then contacts the carbon dioxide adsorbent 4 made of synthetic zeolite. Then carbon dioxide is removed. The refrigerant 24 from which carbon dioxide has been removed passes through the check valve 22 and the compressor suction portion 23 and returns to the compressor 11. Since the refrigerant 24 returned to the compressor does not contain carbon dioxide, which is carbon dioxide, it is easily compressed and the input does not increase.

Since the refrigerant 24 does not contain carbon dioxide which is carbon dioxide, even if it is circulated through the refrigeration system again, the phenomenon like a capillary choke does not occur and the refrigerating capacity does not deteriorate.

As described above, according to this embodiment, the refrigerant 24
The second filter 3 for removing the non-condensable gas component in the inside is provided in the low temperature portion between the evaporator 19 and the compressor suction portion 23 to adsorb carbon dioxide in a low temperature state. A large amount of carbon dioxide can be retained in the adsorbent.

[0032]

As described above, the refrigeration system of the present invention is
A compressor in which a refrigerant composed of a halogenated carbon compound substituted with at least one hydrogen and refrigerating machine oil dissolved in the refrigerant are enclosed; and a mechanical section housed in the compressor.
By providing a condenser connected to the compressor, an evaporator, a first filter filled with a desiccant and a second filter filled with a carbon dioxide adsorbent, the carbon dioxide in the refrigerant can be quickly and in large quantities. Therefore, the refrigerating capacity is not lowered due to the capillary choke phenomenon, and the input is not increased because it is difficult to be compressed.

Further, in order to remove the non-condensable gas component in the refrigerant, this second filter is provided between the compressor discharge part in which the refrigerant is in a gas-liquid mixed phase state and the first filter, or is evaporated. Since it is provided between the compressor and the compressor suction part, carbon dioxide can be efficiently removed without being affected by the condensed refrigerant.

[Brief description of drawings]

FIG. 1 is a piping diagram of a refrigeration system showing an embodiment of the present invention.

FIG. 2 is a piping diagram of a refrigeration system showing another embodiment of the present invention.

[Fig. 3] Piping diagram of a conventional refrigeration system

[Explanation of symbols]

 1, 3 Second filter 2, 4 Carbon dioxide adsorbent 13 Compressor discharge part 15 First filter 19 Evaporator 23 Compressor suction

Claims (4)

[Claims] 1. A refrigerant comprising a halogenated carbon compound substituted with at least one hydrogen, a compressor enclosing a refrigerating machine oil dissolved in the refrigerant, a mechanical section housed in the compressor, and A refrigeration system comprising a condenser connected to a compressor, an evaporator, a first filter filled with a desiccant, and a second filter filled with a carbon dioxide adsorbent. 2. The refrigerant is 1,1,1,2-tetrafluoroethane, the refrigerating machine oil is a carbonate type oil, and the adsorbent filled in the second filter adsorbs carbon dioxide. The refrigeration system according to claim 1, which is a synthetic zeolite. 3. The refrigeration system according to claim 1, wherein a second filter for removing a non-condensable gas component in the refrigerant is provided between the compressor discharge part and the first filter. 4. The refrigeration system according to claim 1, wherein a second filter for removing a non-condensed gas component in the refrigerant is provided between the evaporator and the compressor suction part.