JP2002022294A - Refrigeration device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent shortage of lubricating oil from occurring in any of a plurality of compressors installed parallelly in a single refrigerant circuit. SOLUTION: A refrigeration device is provided with an oil balance pipe 10 from a high pressure section H of the compressor 1 to a refrigerant suction pipe 5 connected with the compressor 2 and an oil balance pipe 12 from a high pressure section H of the compressor 2 to a refrigerant suction pipe 4 connected with the compressor 1. A capillary tube 11 is installed in a halfway position of the oil balance tube 10 and a capillary tube 13 is installed in a halfway position of the oil balance tube 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating apparatus (including an air conditioner) including a plurality of compressors for compressing a refrigerant in parallel.

[0002]

2. Description of the Related Art Generally, in a refrigerating apparatus in which a plurality of compressors provided with an oil reservoir for storing lubricating oil (hereinafter simply referred to as oil) in a low-pressure section are connected in parallel, the oil reservoirs are mutually connected. Communicating through an oil balance pipe,
I try to keep the oil balance.

However, when at least one of the compressors is a compressor whose capacity can be controlled, or in a refrigeration system which is large in size by connecting a plurality of compressors having different compression capacities in parallel, the pressure inside the compression vessel is increased. Due to the difference, oil is sucked into the high-output compressor, etc., the oil increases in the high-output compressor, the oil runs short in the low-output compressor, and the sliding part of the compressor runs out of oil. This leads to a problem that wear is advanced and the life of the apparatus is shortened.

In order to eliminate the unbalance in the amount of oil, it is necessary to connect an oil balance pipe having a large diameter to a compressor having a large output. However, when the compressor is started, stress is applied to the oil balance pipe. However, there is also a problem that the oil balance pipe becomes complicated and the cost increases.

A refrigerating apparatus having a structure in which a compressor having a container structure in which a low-pressure section and a high-pressure section are partitioned via a discharge port of a compression pump and a plurality of internal high-pressure compressors are connected in parallel. An oil sensor that detects the oil level surface is provided for each compressor, and the amount of oil returned from the oil separator is controlled based on the state of the oil level surface to maintain the balance of the oil amount of each compressor. ing.

However, there is a problem that the oil sensor has a complicated structure and is expensive. There is also a problem that the control circuit for returning the oil is complicated and expensive.

[0007]

For this reason, even if the refrigerant compression capacity of the compressor is different or the flow resistance of the refrigerant discharge pipe is different, the simple structure that does not increase the cost causes oil shortage. It is necessary to prevent the compressor from occurring,
That was a problem to be solved.

[0008]

According to the present invention, as a specific means for solving the above-mentioned problems of the prior art, a compression of a container structure in which a low pressure part and a high pressure part are partitioned via a discharge port of a compression pump. In a refrigerating apparatus having a refrigerant circuit in which a plurality of compressors are installed in parallel, an oil balance pipe having a decompression means from a high pressure part of a compressor to a refrigerant suction pipe of another compressor is installed. A refrigerating device having a configuration,

A refrigerant circuit in which a first compressor having a container structure and a second compressor having a high-pressure container structure in which a low-pressure section and a high-pressure section are partitioned via a discharge port of a compression pump is provided. In the refrigerating apparatus provided, an oil balance pipe provided with a decompression means from a high-pressure section of the first compressor to a refrigerant suction pipe of the second compressor is installed, and the oil balance pipe is provided from the vicinity of a prescribed oil level surface of the second compressor. A refrigerating device having a second configuration in which an oil balance pipe having a decompression means leading to a refrigerant suction pipe of the first compressor is provided;

The refrigeration system of the first or second configuration, wherein one end of an oil balance pipe is connected to an uphill portion of a branched refrigerant suction pipe,

In the refrigeration system of any one of the first to third configurations, the refrigerant discharge pipe is connected to the compressor horizontally, and
A fourth configuration in which one end of the oil balance pipe is connected to a position below the refrigerant discharge pipe connection portion where a center angle θ standing on an arc between the refrigerant discharge pipe and the oil balance pipe is 45 degrees or less. By providing a refrigeration apparatus having the above configuration, the above-described problem of the related art is solved.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] A first embodiment of the present invention will be described below in detail with reference to FIGS. In the drawing, reference numerals 1 and 2 denote compressors which constitute a refrigerating apparatus together with a condenser, an evaporator and the like (not shown), and are installed in parallel in one refrigerant circuit.

The compressors 1 and 2 in this case are low-pressure scroll type compressors having a container structure, and a low-pressure section L and a high-pressure section H are partitioned via a discharge section P1 of a compression pump P. . The oil 20 for lubrication is stored at the bottom of the low-pressure section L.

One low pressure section L of the compressor 1 is connected to one refrigerant suction pipe 4 branched from the refrigerant suction pipe 3, and another low pressure section L of the compressor 2 is connected to the other refrigerant suction pipe 5 branched from the refrigerant suction pipe 3. Is connected.

A high pressure section H of the compressor 1 is connected to a discharge refrigerant pipe 6.
Is connected to the high-pressure section H of the compressor 2 so that the high-pressure refrigerant discharged to the discharge refrigerant pipes 6 and 7 joins and can be circulated and supplied to a not-shown condenser, evaporator, or the like. A discharge refrigerant merging pipe 8 is provided. An accumulator 9 is installed in the refrigerant suction pipe 3, and a check valve is installed in each of the refrigerant discharge pipes 6 and 7.

Further, an oil balance pipe 10 extending from the high pressure portion H of the compressor 1 to the refrigerant suction pipe 5 is provided, and a capillary tube 11 as a pressure reducing means is provided in the oil balance pipe 10. Further, an oil balance pipe 12 extending from the high pressure section H of the compressor 2 to the refrigerant suction pipe 4
The oil balance pipe 12 is provided with a capillary tube 13 as pressure reducing means.

The refrigerant discharge pipes 6, 7 are horizontally mounted on the compressors 1, 2 as shown in FIG. 2, and one ends of oil balance pipes 10, 12 are connected below them.
At this time, each of the refrigerant discharge pipe 6 and the oil balance pipe 10 and the refrigerant discharge pipe 7 and the oil balance pipe 12 have a center angle θ of 4
It is connected to a position within 5 degrees.

The other ends of the oil balance pipes 10 and 12 are connected to uphill portions of the refrigerant suction pipes 5 and 4 branched from the refrigerant suction pipe 3.

In the refrigerating apparatus having the above-described structure, in both the compressors 1 and 2, the oil 20 that has lubricated the sliding portion of the compression pump P is discharged together with the compressed refrigerant to the high-pressure section H, and there is a space in the high-pressure section H. In this case, the oil 20 separates from the refrigerant and accumulates at the bottom of the high-pressure section H.

The discharge part P1 is compressed by the compression pump P
The high-pressure refrigerant that has entered the high-pressure section H from is discharged to the refrigerant discharge pipes 6, 7, so that the flow rate from the discharge section P1 to the connection between the refrigerant discharge pipes 6, 7 is large, and therefore, the oil 20 separated from the refrigerant is Many accumulate below the flow path.

The oil balance pipe 1
Since one end of each of the compressors 0 and 12 is connected, the oil 20 accumulated in the high-pressure section H of the compressor 1 flows through the oil balance pipe 10 and the refrigerant suction pipe 5 together with the refrigerant gas in the low-pressure section L of the compressor 2.
Oil 2 sucked into the compressor 2 and accumulated in the high-pressure section H of the compressor 2
0 is sucked into the low-pressure section L of the compressor 1 together with the refrigerant gas through the oil balance pipe 12 and the refrigerant suction pipe 4, and the oil 20 stored at the bottom of each is replenished.

At this time, the compressor 1 to the compressor 2, the compressor 2
The oil 20 supplied to the compressor 1 is only the oil 20 which has lubricated the sliding parts of the respective compression pumps P and discharged to the high pressure part H, and is drawn out to the oil 20 stored in the low pressure part L. Since there is no
Even if there is a difference in the ability to compress the refrigerant, there is no inconvenience that the oil 20 accumulates unevenly in one of the compressors 1 and 2 and the oil 20 runs short in the other compressor.

When one compressor, for example, the compressor 1 is operating and the other compressor 2 is stopped, the flow of the refrigerant gas toward the compressor 2 via the refrigerant suction pipe 5 is Therefore, the sliding part of the compression pump P is lubricated and discharged to the high-pressure part H of the compressor 1, and the oil 20 accumulated at the bottom thereof is supplied to the oil balance pipe 10, a part of the refrigerant suction pipe 5 and the refrigerant suction pipe 5. The refrigerant gas is sucked into the compressor 1 through the pipe 4.
For this reason, there is no inconvenience that the compressor 1 runs out of oil.

Moreover, the refrigerant discharge pipe 6 and the oil balance pipe 10 and the refrigerant discharge pipe 7 and the oil balance pipe 12 are mounted on the compressors 1 and 2 in a state where the center angle θ is close to 45 degrees or less. Therefore, the oil 20 separated at the high-pressure section H of the compressor 1 is supplied to the low-pressure section L of the compressor 2, and the oil 20 separated at the high-pressure section H of the compressor 2 is supplied to the low-pressure section L of the compressor 1. Well supplied.

[Second Embodiment] Hereinafter, a second embodiment of the present invention will be described with reference to FIG. In the refrigeration apparatus shown in FIG. 3, parts having the same functions as those of the refrigeration apparatus shown in FIGS. 1 and 2 are denoted by the same reference numerals for easy understanding.

The refrigerating apparatus shown in FIG. 3 includes a low-pressure scroll type compressor 1 having the same structure as the compressors 1 and 2 shown in FIG. 1 and a compressor 2A having a high-pressure vessel structure different from the low-pressure scroll type compressor. This is a refrigerating device installed in parallel with the refrigerant pipe.

In this refrigerating apparatus, the high pressure section H of the compressor 1 and the refrigerant suction pipe 5 are connected by an oil balance pipe 10 having a capillary tube 11,
The vicinity of a prescribed oil level surface of the compressor 2A and the refrigerant suction pipe 4
Are connected by an oil balance pipe 14 having a capillary tube 15.

In the refrigerating apparatus having the above structure, the compressor 1
The oil 20 that has lubricated the sliding portion of the compression pump P is discharged together with the compressed refrigerant to the high-pressure section H and accumulates at the bottom of the high-pressure section H. Then, the oil 2 accumulated in the high-pressure section H of the compressor 1
0 is sucked into the compression pump P of the compressor 2A together with the refrigerant gas through the oil balance pipe 10 and the refrigerant suction pipe 5, and a part of the oil 20 mixed into the compressed gas is discharged to the discharge refrigerant pipe 7 together with the refrigerant gas. However, the oil 20 separated in the high-pressure portion H accumulates at the bottom thereof and is supplied to each sliding portion.

On the other hand, the oil 20 accumulated in the high-pressure section H of the compressor 2A passes through the oil balance pipe 14 connected near the prescribed oil level surface, a part of the refrigerant suction pipe 5, and the refrigerant suction pipe 4. As a result, the oil 20 is sucked into the low-pressure section L of the compressor 1 together with the refrigerant gas, and the oil 20 accumulated at the bottom is supplied to each sliding section.

In the refrigerating apparatus having the structure shown in FIG.
Since the high-pressure portion H of the low-pressure scroll type compressor 1 is connected to the refrigerant suction pipe 5 to which the compressor 2A having the high-pressure container structure is connected via the oil balance pipe 10, the compressor 1 Only the oil 20 separated from the refrigerant in the high-pressure section H is supplied to the high-pressure section H, and a large amount of oil 20 stored in the low-pressure section L is not sucked even if the capacity of the compressor 2A is large. Therefore, there is no shortage of oil 20 in the compressor 1.

The oil 20 stored in the high-pressure section H of the compressor 2A also has a lower oil level than the specified oil level because the oil balance pipe 14 is connected near the specified oil level surface. The oil is not drawn out to the compressor 1 through the pipe 14, so that the oil 20 does not run short even in the compressor 2A.

Since the present invention is not limited to the above embodiment, various modifications can be made without departing from the spirit of the appended claims.

For example, in the refrigerating apparatus of the first embodiment shown in FIG. 1, when a total of n (n ≧ 3) compressors are installed, the second compressor is connected to the high pressure section of the first compressor. An oil balance pipe provided with a pressure reducing means leading to the refrigerant suction pipe of the second compressor, and an oil balance pipe provided with a pressure reducing means leading from the high pressure section of the second compressor to the refrigerant suction pipe of the third compressor, An oil balance pipe is similarly installed in order from the high pressure section of the (n-1) th compressor to an oil balance pipe having a decompression means from the refrigerant suction pipe of the nth compressor, and further the nth compressor And an oil balance pipe provided with a decompression means from the high pressure section to the refrigerant suction pipe of the first compressor.

In the compressors 1 and 2 shown in FIG. 1 and the compressor 1 shown in FIG. 3, an oil separating plate is provided in the high-pressure section H, and the central angle θ between the refrigerant suction pipe and the oil balance pipe is set. 4
It can be provided at a position where the angle is 5 degrees or more.

Further, the piping configuration shown in FIG. 1 can be combined with the piping configuration shown in FIG.

[0036]

As described above, according to the present invention, no oil shortage occurs in any of a plurality of compressors installed in parallel. Does not shorten the life of the apparatus.

In particular, according to the third aspect of the present invention, since one end of the oil balance pipe is connected to the upstream portion provided on the ascending slope of the refrigerant suction pipe, the operating compressor is operated independently of the stopped compressor. Oil can be transferred between each other.

Further, according to the fourth aspect, the refrigerant discharge pipe and the oil balance pipe approach each other so that the central angle θ is 45 degrees or less, and the oil balance pipe is connected to the lower side of the refrigerant discharge pipe. Therefore, oil accumulated near the refrigerant discharge pipe connection is efficiently supplied to the other compressor via the oil balance pipe.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a main part of the first embodiment.

FIG. 3 is an explanatory diagram showing a second embodiment of the present invention.

[Explanation of symbols]

 1, 2 Compressor 3, 4, 5 Refrigerant suction pipe 6, 7 Refrigerant discharge pipe 8 Discharge refrigerant merging pipe 9 Accumulator 10 Oil balance pipe 11 Capillary tube 12 Oil balance pipe 13 Capillary tube 14 Oil balance pipe 15 Capillary tube 20 Oil P Compression pump P1 Discharge part L Low pressure part H High pressure part θ Center angle

 ──────────────────────────────────────────────────の Continuing on the front page (72) Kazugi Sugimoto 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Takashi Sato 2-chome Keihanhondori, Moriguchi-shi, Osaka No. 5-5 Sanyo Electric Co., Ltd. (72) Inventor Junichi Suzuki 2-5-5 Keihanhondori, Moriguchi-shi, Osaka F-term in Sanyo Electric Co., Ltd. 3H003 AA05 AB01 AC03 BD12 CD07 3H076 AA01 AA39 BB17 BB26 BB43 CC62 CC69 CC77 CC94

Claims (4)

[Claims] 1. A refrigerating apparatus comprising a refrigerant circuit in which a plurality of compressors having a container structure in which a low-pressure part and a high-pressure part are divided via a discharge port of a compression pump are provided in parallel. A refrigerating apparatus, comprising: an oil balance pipe provided with a decompression means extending from a compressor to a refrigerant suction pipe of another compressor. 2. A refrigerant in which a first compressor having a container structure and a second compressor having a high-pressure container structure in which a low-pressure portion and a high-pressure portion are separated via a discharge port of a compression pump are arranged in parallel. In a refrigerating apparatus provided with a circuit, an oil balance pipe provided with a pressure reducing means from a high pressure section of the first compressor to a refrigerant suction pipe of the second compressor is installed, and a specified oil level surface of the second compressor is provided. A refrigerating apparatus, comprising: an oil balance pipe provided with a decompression means extending from the vicinity to a refrigerant suction pipe of the first compressor. 3. The refrigeration system according to claim 1, wherein one end of the oil balance pipe is connected to an uphill portion of a branched refrigerant suction pipe. 4. A refrigerant discharge pipe is horizontally connected to the compressor, and a central angle θ above the arc between the refrigerant discharge pipe and the oil balance pipe below the refrigerant discharge pipe connection portion is 45 degrees. 4. The refrigeration apparatus according to claim 1, wherein one end of the oil balance pipe is connected to the following position.