JPH0933120A - Refrigerating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigerating device, reduced in the generation of waste and capable of reducing a resistance in a refrigerant circuit while equipped with a dryer. SOLUTION: In a refrigerating device, a compressor 1 is equipped with a circulating circuit 21, circulating oil and different from a refrigerant circuit, while the circulating circuit is equipped with a circulating pump 23 and a dryer 25, filtering moisture from oil which flows through the circulating circuit. Accordingly, the dryer 25 will never become the resistance of the refrigerant circuit and, further, the generation of waste, generated by the rubbing of moisture filter mediums with each other, can be reduced. On the other hand, the moisture can be removed at any arbitrary time regardless to the circulation of the refrigerant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating apparatus in which a refrigerant is circulated in a refrigerant circuit, and more particularly to a refrigerating apparatus using a so-called HFC-based non-azeotropic refrigerant mixture which does not use chlorine as a refrigerant.

[0002]

2. Description of the Related Art Conventionally, a refrigerant used in a refrigeration system is dichlorodifluoromethane (hereinafter referred to as "R-1").
2)) and R-12 which is an azeotropic refrigerant mixed refrigerant and R-500 composed of 1,1-difluoromethane (hereinafter referred to as "R-152a"). The boiling point of R-12 is −29.65 ° C. at atmospheric pressure, and the boiling point of R-500 is −33.45 ° C., which is suitable for ordinary refrigeration equipment and is suitable for CF such as R-12.
Refrigeration cycles that use refrigerating machine oils such as mineral oils and alkylbenzene-based oils that are compatible with C-based refrigerants have a history of about 30 years, and efforts have been made to improve the refrigeration cycle, resulting in high quality levels such as reliability and durability. Has reached.

[0003] However, each of the above-mentioned refrigerants is destroyed when it is released into the atmosphere and reaches the ozone layer above the earth due to its high ozone depletion potential.
The destruction of the ozone layer is caused by chlorine groups (Cl) in the refrigerant. Therefore, a refrigerant having a low chlorine group content, such as chlorodifluoromethane (HCFC-22,
Hereinafter referred to as "R-22"), a refrigerant containing no chlorine group, such as difluoromethane (HFC-32, hereinafter referred to as "R-3"
2 ”), pentafluoroethane (HFC-12
5, hereinafter referred to as “R-125”) and 1,1,1,2-tetrafluoroethane (HFC-134a, hereinafter referred to as “R-134a”) are considered as alternative refrigerants.

It has been considered that one of the important factors is that the refrigerating machine oil used for these HFC-based refrigerants is first compatible with the HFC-based refrigerant.
Since mineral oils, alkylbenzenes, and the like have poor compatibility, it has been considered that refrigeration cycles and refrigeration systems that use both in combination cannot operate stably for a long period of time.

However, a refrigerating cycle using an ester type lubricating oil, an ether type lubricating oil or a mixed lubricating oil thereof as a refrigerator having a good compatibility with an HFC type refrigerant is a conventional CFC.
Compared with a refrigeration cycle using an HCFC-based refrigerant (designated CFC), there is a large problem that lubricity, electrical characteristics, etc. tend to deteriorate.

There are various possible causes for this, but ester-based lubricating oils and the like used in combination with HFC-based refrigerants are not sufficiently effective as extreme pressure agents, and may cause friction and wear of sliding parts inside the compressor. The temperature tends to rise, sludge components (dust) are likely to be generated due to abrasion, and moisture tends to be absorbed or hydrolyzed. Low water absorption and hydrolyzability, good electrical characteristics, high lubricity, and economical
A lubricating oil that can be used as a mixture with an FC-based refrigerant has not been obtained yet.

That is, the conventional refrigeration system has a disadvantage that water is generated, and the ester-based lubricating oil and the ether-based lubricating oil have high reactivity with water, and if water is present in the refrigerant circuit,
There is a problem that it is hydrolyzed to generate acid, alcohol, etc., and further reacts with worn metal ions to produce metal soap. Then, the metal soap generated by such a reaction adheres to the inner surface of the cylinder of the compressor to reduce the clearance, which causes a malfunction of the compressor.

On the other hand, for example, Heisei 5-1594
Japanese Patent Publication No. 4 discloses a configuration in which a dryer for removing water is provided in the refrigerant circuit.

[0009]

However, when the water removing device (dryer) is arranged in the refrigerant circuit, the refrigerant always passes through the dryer. The refrigerant will pass through the dryer even after the water has been sufficiently removed.

Therefore, the molecular sieves filled in the dryer as a moisture removing material rub against each other,
There is a problem that it may cause generation of scraps and increase resistance in the refrigerant circuit.

Therefore, it is an object of the present invention to provide a refrigerating apparatus having a dryer capable of reducing the generation of waste and reducing the resistance in the refrigerant circuit.

[0012]

According to a first aspect of the present invention, there is provided a refrigeration system including a refrigerant circuit in which a compressor, a condenser, a pressure reducer, and an evaporator are annularly connected by a refrigerant pipe. A circulation circuit that circulates oil in the compressor is provided separately from the refrigerant circuit, and the circulation circuit includes a circulation pump and a dryer that removes moisture from the oil flowing through the circulation circuit.

In the refrigerating apparatus according to the present invention, a circulation circuit for circulating the oil of the compressor is provided separately from the refrigerant circuit, and the dryer is provided in this circulation circuit. Therefore, the dryer is the refrigerant circuit. It does not become a resistance of, and the generation of waste can be further reduced. Moreover, since the dryer is provided in the circulation circuit different from the refrigerant circuit, the moisture can be removed at any time.

According to a second aspect of the present invention, in a refrigeration system including a refrigerant circuit in which a compressor, a condenser, a pressure reducer, and an evaporator are annularly connected by a refrigerant pipe, the compressor removes oil in the compressor. A circulation circuit for circulation is provided separately from the refrigerant circuit, and this circulation circuit includes a circulation pump, a dryer for removing moisture from oil flowing through the circulation circuit, and an oil filter for removing dust.

In the invention described in claim 2, claim 1
In addition to the invention described in (1), since the oil filter is provided in the circulation circuit, it is possible to remove the moisture in the oil and simultaneously remove the sludge and the debris of the moisture removing material.

According to a third aspect of the present invention, in a refrigerating apparatus including a refrigerant circuit in which a compressor, a condenser, a decompressor, and an evaporator are annularly connected by a refrigerant pipe, the compressor removes oil in the compressor. A circulation circuit that circulates is provided separately from the refrigerant circuit, and the circulation circuit includes a circulation pump, a dryer that removes moisture from oil flowing through the circulation circuit, and a control device that drives the circulation pump at an arbitrary time. It is a thing.

According to the invention described in claim 3, claim 1
In the invention described in (3), the control device arbitrarily controls the drive timing of the circulation pump. Therefore, the water can be efficiently removed by driving the circulation pump at an arbitrary time when the water is likely to accumulate.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

As shown in FIG. 1, in the refrigerating apparatus of this embodiment, a compressor 1, a condenser 2, a capillary tube 3 as a decompressor, an evaporator 4 and an accumulator 5 are serially arranged in this order by a refrigerant pipe. They are connected and a refrigeration cycle (refrigerant circuit) is formed.

In such a refrigeration cycle, the high-temperature and high-pressure gas compressed by the compressor 1 radiates heat in the condenser 2 to be condensed and liquefied, and then decompressed in the capillary tube 3 to absorb external heat in the evaporator 4. Evaporation is performed to cool the outside of the evaporator 4. Then, the accumulator 5 holds the liquid refrigerant and returns the gas refrigerant to the compressor 1.

The refrigerant used in this embodiment is an HFC type refrigerant and flows in the refrigerant circuit in the direction indicated by the arrow. As a specific HFC refrigerant, R-32 is 23
%, R-125 25% by weight, R-143a 52% by weight, R-134a 4% by weight (so-called 4
07c refrigerant) or 44% by weight of R-125, R-143
In addition to a mixed refrigerant (so-called 404a refrigerant) containing 52% by weight of a and 4% by weight of R-134a, a single refrigerant of R-134a is used.

As the lubricating oil (oil) mixed with the refrigerant, ester lubricating oil compatible with the HFC refrigerant is used. The lubricating oil may be an ether lubricating oil or a mixed oil of an ester lubricating oil and an ether lubricating oil. The lubricating oil is stored in the compressor 1 during operation and soaks the compression portion located at the bottom of the compressor 1. Thus, the ester-based lubricating oil has a lubricating function of the compression part, a cooling function of releasing heat due to refrigerant compression, and a gas sealing function.

The type of the compressor 1 is not particularly limited, and various types such as a rotary type, a reciprocating type, or a scroll type are used. In this embodiment, a rotary type compressor is used as an example, and in the hermetically sealed container 11, an electric motor 12, an insulating coated electric wire 13, and a cylinder 1 are used.
4, bearing 15 is arranged.

Oil is stored at the bottom of the compressor 1,
A circulation circuit 21 for circulating the oil stored in the compressor 1 is provided. The circulation circuit 21 is provided with a circulation inlet 21a connected to the bottom or lower side of the closed container and a circulation outlet 21b connected to the middle side (middle of the height direction) of the container. In the circulation circuit 21, a circulation pump 23 and a dryer 25 for removing water are arranged. That is, in this embodiment, since the dryer 25 is not provided in the refrigerant circuit, the refrigerant in the refrigerant circuit does not always pass through the dryer 25. Therefore, the resistance in the refrigerant circuit can be reduced, and dust is not mixed due to sliding between the water removing materials 29 (described later).

The circulation pump 23 is connected to the control device 27 and is started upon receiving a drive signal from the control device 27 and stopped upon receiving a stop signal.

As shown in the enlarged view of FIG. 2, the dryer 25 has an inlet 27a into which oil is introduced in one side of the main body 27 and an outlet 27b in the other side.
The main body 27 is filled with a moisture removing material 29 on the inlet side thereof and an oil filter 33 is stored on the outlet side thereof.

The moisture removing material 29 is not particularly limited,
For example, molecular sieves are used.

The moisture removing material 29 is provided at the inlet 27a of the main body 27.
On the side (upstream side), it is held by the wire nets 31, 31 and an oil filter 33 is housed on the outlet 27b side, which is the downstream side, to remove dust and dirt in the oil. Thus, by disposing the oil filter 33 on the downstream side of the water removing material 29, even if dust or the like is generated due to the sliding of the molecular sieves, it can be effectively removed.

Further, in the present embodiment, the dryer 25 is provided with an intervening material such as a partition plate at a predetermined distance from the compressor 1 or between the dryer 25 and the compressor 1 so as not to receive the heat of the compressor 1 directly. It is located in. As described above, the dryer 25 is not directly heated by the influence of the compressor, so that it is possible to prevent the molecular sieves from being decomposed or deteriorated by heat.

Although the circulation circuit 21 is not provided with an on-off valve for opening and closing the circuit in this embodiment, an on-off valve may be provided if necessary.

Next, the operation of this embodiment will be described.

During normal operation in the refrigerant circuit, the compressor 1 is driven, and the refrigerant flows in the order of the condenser 2, the capillary tube 3, the evaporator 4, and the accumulator 5, and is compressed by the compressor 1 at high temperature and high pressure. The gas radiates heat in the condenser 2,
After condensing and liquefying, the evaporator 4 absorbs heat from the outside and evaporates to cool the outside of the evaporator 4.

During this normal operation, the circulation pump 23 is stopped, and the circulation circuit 2 for removing the water content of the refrigerant.
No oil flows into 1.

When the compressor of the refrigerant circuit is stopped, for example, when the operation of the refrigerant circuit is stopped, the control device 27 issues a drive command to the circulation pump 23 to remove the oil accumulated at the bottom of the compressor 1. It is circulated to the circulation circuit 21. In this case, the control device 27 drives the circulation pump 23 in all cases when the stop of the compressor 1 is detected, and at a predetermined time, for example, after the entire refrigerant circuit is stopped or before starting, or when the refrigerating device is installed. The circulation pump 23 may be operated only after the trial operation, and the control device 27 issues a drive command to the circulation pump 23 at a preprogrammed time.

Of course, when the compressor 1 is stopped during the defrosting operation, the circulation pump 23 may be driven during the defrosting operation.

The reason why the circulation pump 23 is driven when the compressor 1 is stopped is that a predetermined amount of oil is not accumulated in the bottom portion when the compressor 1 is driven.

When the circulation circuit 21 is driven, oil is taken in from the bottom of the compressor 1, passes through the dryer 25, and then returns to the inside of the compressor 1 through the circulation outlet 21b.

In the dryer 25, the moisture removing material 29 removes the moisture in the oil, and then the oil filter 33
Removes sludge and debris from oil. in this way,
The water removing material 29 is arranged on the upstream side, and the oil filter 33
Is disposed on the downstream side, it is possible to remove together with other dust in the oil even if the dust generated due to the sliding of the moisture removing material 29 leaks out.

The present invention is not limited to the above embodiment,
Various modifications can be made without departing from the spirit of the present invention.

For example, it suffices to drive the circulation pump at any time and for any time while the compressor 1 is stopped, and to drive the circulation pump for any time such as 1 minute or 10 minutes after the lapse of a predetermined operation time. May be

[0041]

According to the refrigerating apparatus of the first aspect of the present invention, an oil circulation circuit for circulating the oil of the compressor is provided separately from the refrigerant circuit, and the dryer is provided in this circulation circuit. The resistance of the circuit does not occur, and the generation of scraps caused by the sliding of the moisture removing materials and the like can be further reduced. In addition, water can be arbitrarily removed regardless of the circulation of the refrigerant.

According to the invention described in claim 2, in addition to the invention described in claim 1, since an oil filter is provided in the refrigerant circuit, at the same time as removing water in the oil,
It is also possible to remove sludge mixed with oil and debris of the moisture removing material.

According to the refrigerating apparatus of claim 3,
In addition to the invention described in (1), the control device arbitrarily controls the drive timing of the circulation pump. Therefore, the water can be efficiently removed by driving the circulation pump at an arbitrary time when the water is likely to accumulate.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a refrigerating apparatus according to an embodiment of the present invention.

FIG. 2 is a sectional view of a dryer used in an embodiment of the present invention.

[Explanation of symbols]

 1 Compressor 21 Circulation Circuit 23 Circulation Pump 25 Dryer 29 Moisture Removal Material 33 Oil Filter

Claims (3)

[Claims] 1. A refrigeration apparatus comprising a refrigerant circuit in which a compressor, a condenser, a decompressor, and an evaporator are annularly connected by a refrigerant pipe, wherein the compressor has a circulation circuit for circulating oil in the compressor. A refrigeration system characterized in that it is provided separately from the circuit, and this circulation circuit comprises a circulation pump and a dryer for removing water from the oil flowing through the circulation circuit. 2. A refrigeration apparatus comprising a refrigerant circuit in which a compressor, a condenser, a decompressor, and an evaporator are annularly connected by a refrigerant pipe, wherein the compressor has a circulation circuit for circulating oil in the compressor. A refrigerating apparatus characterized in that it is provided separately from the circuit, and this circulation circuit comprises a circulation pump, a dryer for removing water from oil flowing through the circulation circuit, and an oil filter for removing dust. 3. A refrigeration apparatus comprising a refrigerant circuit in which a compressor, a condenser, a decompressor, and an evaporator are annularly connected by a refrigerant pipe, wherein the compressor has a circulation circuit for circulating oil in the compressor. A circuit separate from the circuit, and the circulation circuit includes a circulation pump, a dryer that removes water from the oil flowing through the circulation circuit, and a controller that drives the circulation pump at an arbitrary time. .