JP2722819B2 - Combined compression device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

This invention comprises a plurality of compressors,
The present invention relates to a connection type compression device suitable for a relatively large-scale refrigeration system such as a building air conditioning system.

[0002]

2. Description of the Related Art Conventionally, as a compression apparatus of this kind, there has been known a compression apparatus disclosed in Japanese Patent Application Laid-Open No. 2-173667.

[0003] As shown in FIG. 3, a compressor D includes first and second compressors A and B in which a compression element C is provided in a casing D having an oil reservoir O, respectively. , An oil equalizing pipe T for connecting the oil reservoirs O is connected.

[0004] A second suction pipe L connected to the second compressor B is branched in the middle of the first suction pipe H connected to the first compressor A. The first compressor A is forcibly set to the high pressure side and the second compressor B is forcibly set to the low pressure side by projecting inward from the inner wall surface and providing a difference in pressure loss in the suction path.

[0005] An oil separator S is interposed between the first and second discharge pipes P, Q extending from the compressors A, B and the discharge main pipe M, and the bottom of the oil separator S is connected to the first and second discharge pipes. An oil return path R having a pressure reducing mechanism V on the way is connected to one suction pipe H.

Thus, the oil separated from the discharge gas by the oil separator S is returned to the first suction pipe H, and the returned oil is transmitted along the inner wall surface of the first suction pipe H due to the wettability of the oil, so that the oil on the high pressure side is removed. The oil is returned to the first compressor A, and an equalizing pipe T is provided from the first compressor A on the high pressure side to the second compressor B on the low pressure side where the return oil returns.
The oil is moved through the compressor so that an appropriate oil level can be secured in each of the compressors A and B.

[0007]

However, each compressor A,
To maintain the oil levels of both B properly, the first compressor A on the high pressure side
In addition, it is necessary to return a sufficient and sufficient amount of oil to replenish the amount of moving oil transferred to the second compressor B on the low pressure side through the oil equalizing pipe T. The part E protrudes into the inside of the first suction pipe H, so that the oil traveling along the inner wall of the first suction pipe H due to the wettability of the oil does not flow into the second suction pipe L, and the oil is returned to the first compressor A. Although the oil is concentrated, the oil separated by the oil separator S is in a high-temperature state separated from the high-pressure and high-temperature discharge gas. In one compressor A, the intake gas is overheated excessively, the volume efficiency in the first compressor A deteriorates, and the efficiency of only the first compressor A on the high pressure side decreases.

In particular, in the case of using a scroll type compression element as the compression element, it is necessary to secure a sufficient oil supply to the scroll spiral body. This problem is conspicuous because a large amount of oil is returned to the oil return path R.

An object of the present invention is to connect a plurality of compressors,
Provided is a connection-type compression device that can improve the efficiency of a high-pressure side compressor by preventing overheating of excessive suction gas in a high-pressure side compressor while performing oil level correction using a forced differential pressure. Is to do.

[0010]

In order to achieve the above object, the present invention comprises a plurality of compressors 1 and 2 in which a compression element is provided in a casing having an oil sump. In the connection-type compression device in which the oil equalizing pipe 7 is connected between the two, the first suction device connected to the compressor 1 on the high pressure side
In the inside of the inlet pipe 3, the second connecting to the compressor 2 on the low pressure side
Forced differential pressure means 5 for projecting the end of the suction pipe 4 to forcibly generate a pressure difference inside the casing of each of the compressors 1 and 2; an oil separator 6 for separating the oil separated by the oil separator 6
And the oil return passage 8 back to the compressor 1, a high pressure side, and an oil cooler 9 to cool the oil flowing through the oil return passage 8 provided, wherein
The position of the first suction pipe 3 on the upstream side of the entry portion of the second suction pipe 4
The oil return path 8 is attached to the
Thus, the oil cooler 9 was configured.

[0011]

The hot oil separated from the discharge gas by the oil separator 6 passes through the oil return path 8 through the oil return path 8 to the first suction pipe 3.
Heat exchange possible at the position upstream of the entrance of the second suction pipe 4
The oil is cooled by an oil cooler 9 which is additionally provided to the compressor and returned to the compressor 1 on the high pressure side. Thereby, the gas is supplied to the second suction pipe 4.
Before the gas is diverted into the first suction pipe 3 with a large amount of gas.
Oil can be cooled well without direct contact with other gases
Thus, it is possible to prevent excessive overheating of the intake gas in the high-pressure side compressor 1.

The oil is moved from the high-pressure side compressor 1 to the low-pressure side compressor 2 through the oil equalizing pipe 7, so that the oil levels of the compressors 1 and 2 are properly maintained.

Further, the oil cooler 9 is connected to each compressor 1,
The structure of the oil path for performing a second oil level corrective configured by effectively using
Therefore, return oil can be easily cooled.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The connecting type compression apparatus shown in FIG. 1 is of a twin type having first and second compressors 1 and 2, and each of the compressors 1 and 2 has oil reservoirs 10 and 20 at the bottom, respectively. Compression elements 12, 22 in closed casings 11, 21 having
Motors 14 and 24 having drive shafts 13 and 23 for driving the compression elements 12 and 22 are provided. Each compression element 1
Reference numerals 2 and 22 denote scroll-type ones, which release high-pressure and high-temperature discharge gas after being compressed into discharge chambers 15 and 25 provided above the casings 11 and 21, respectively.

Between the first compressor 1 and the second compressor 2, there are provided pipes 71 and 72 which open downward with respect to the specified oil levels of the oil reservoirs 10 and 20, respectively. The oil equalizing pipe 7 provided with a narrowing means 70 using a thin pipe 73 is connected.

In the above configuration, the second suction pipe 4 connected to the second compressor 2 is branched in the middle of the first suction pipe 3 connected to the first compressor 1 as shown in FIG. The branch start end 41 is located protrudingly inward of the inner wall of the first suction pipe 3 to increase the pressure loss of the second suction pipe 4 with respect to the first suction pipe 3, The forced differential pressure means 5 is configured such that the inside of the casing 11 of the compressor 1 is on the high pressure side and the casing 21 of the second compressor 2 is on the low pressure side.

Further, oil is separated from the discharge gas of each of the compressors 1 and 2 between the first and second discharge pipes 16 and 26 connected to the discharge chambers 15 and 25 and the discharge main pipe 60 integrating them. The oil separator 6 is interposed.

Further, between the bottom of the oil separator 6 and the downstream side of the first suction pipe 3 where the second suction pipe 4 protrudes, the oil separated by the oil separator 6 is first compressed on the high pressure side. An oil return path 8 using a thin tube or the like returned to the machine 1 is connected.

Further, a coil-shaped heat exchange section 81 is provided in the oil return path 8, and this heat exchange section 81 is connected to the first suction pipe.
The oil cooler 9 cools the oil flowing through the oil return path 8 by, for example, being wound around the outer periphery of the second suction pipe 4 on the upstream side of the entry portion of the second suction pipe 3 so as to exchange heat with the first suction pipe 3.

With the above configuration, the high-temperature oil separated from the discharge gas by the oil separator 6 passes through the oil return path 8 and the oil cooler 9 from the first suction pipe 3 to the first compressor on the high pressure side. Returned to 1. At this time, the high-temperature return oil is supplied to the oil cooler 9.
Is cooled by the suction gas having a large flow rate before branching to the second compressor 2 through the first suction pipe 3. For this reason, the oil temperature returned to the first compressor 1 on the high pressure side can be reduced, and it is possible to prevent only the suction gas of the first compressor 1 from being excessively overheated. It is possible to suppress a decrease in efficiency.

In the above construction, the forced differential pressure means 5 is provided inside the first suction pipe 3 connected to the compressor 1 on the high pressure side, and the second suction pipe 4 connected to the compressor 2 on the low pressure side. And the oil cooler 9 is configured such that the oil return path 8 is attached to the first suction pipe 3 located upstream of the second suction pipe 4 so as to be heat exchangerable. Therefore , the structure of the oil path for correcting the oil level of each of the compressors 1 and 2 can be effectively utilized , and the return oil can be easily cooled without providing a special cooler.
You.

[0022] Further, in the above embodiment, although the ones twin type, it goes without saying can equally to the concatenation of the compressor three or more applications.

Further, the scroll element is of a scroll type as the compression element.
When using oil, a large amount of oil flows out to the outside together with the discharge gas.
The amount of oil separated and returned by the oil separator 6 is also large.
Scroll oil is cooled by an oil cooler 9 to provide a scroll type
Of the compressor 1 on the high pressure side
It is possible to prevent excessive suction gas from overheating, and the high pressure side compressor 1
In this case, a decrease in efficiency can be suppressed.

[0024]

As described above, according to the present invention, the pressure on the high pressure side
The inside of the first suction pipe 3 connected to the compressor 1 has a low pressure side.
With the end of the second suction pipe 4 connected to the compressor 2 protruding,
A forced differential pressure means 5 for forcibly generating a pressure difference inside the casing of each of the compressors 1 and 2; an oil separator 6 for separating oil from gas discharged from the compressors 1 and 2; and the oil return passage 8 for returning the separated oil in the vessel 6 to the compressor 1, a high pressure side, and an oil cooler 9 to cool the oil flowing through the oil return passage 8 provided, first in the first suction pipe 3 two Sucking
The oil return path 8 is heat-exchanged at a position on the upstream side of the entrance of the inlet pipe 4.
The oil cooler 9 is constituted by being replaceably attached.
And because, hot oil separated from the discharge gas by the oil separator 6
From the oil return path 8 to the first suction pipe 3
Heat exchange possible at the position upstream of the entrance of the second suction pipe 4
After cooling with an oil cooler 9 attached to the
Can be returned to the plurality of compressors 1,
2 while maintaining the oil level properly, the second suction pipe 4
Before the gas is diverted to the first suction pipe 3 with a large amount of gas,
To cool the oil without direct contact with this gas.
And the kill of, can prevent excessive overheating of the suction gas in the compressor 1 on the high pressure side to return the separated oil in the oil separator 6, it is possible to improve the efficiency in the compressor 1 of the high-pressure side.

Further, the oil cooler 9 is connected to each compressor 1,
The structure of the oil path for performing a second oil level corrective configured by effectively using
Therefore, return oil can be easily cooled.

[Brief description of the drawings]

FIG. 1 is a piping diagram showing the overall structure of a connection-type compression device according to the present invention.

FIG. 2 is a sectional view of a main part showing a structure of the forced differential pressure means.

FIG. 3 is a piping diagram showing a conventional connection-type compression device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 First compressor 2 Second compressor 3 First suction pipe 4 Second suction pipe 5 Forced differential pressure means 6 Oil separator 7 Equalizing oil pipe 8 Oil return path 9 Oil cooler

Claims (1)

(57) [Claims] 1. A plurality of compressors (1) and (2) each having a compression element mounted in a casing having an oil reservoir, and an oil equalizing pipe (7) is provided between the compressors (1) and (2). A first suction pipe (3) connected to the compressor (1) on the high pressure side in the connected connected type compression device.
Of the second suction port connected to the compressor (2) on the low pressure side
With the end of the inlet pipe (4) protruding, each of the compressors (1),
(2) a forced differential pressure means (5) for forcibly generating a pressure difference inside the casing, and an oil separator (6) for separating oil from gas discharged from the compressors (1) and (2). , this oil separator oil return passage for returning the separated oil to the high pressure side to become the pressure <br/> compressor (1) (6) (8), cooling the oil flowing through the oil return passage (8) Oil cooler (9)
The door is provided, the inrush of the second suction pipe in the first suction pipe (3) (4)
The oil return path (8) is heat exchangeable at a position upstream of the section
The oil cooler (9) is constituted by being attached.
Linked compression apparatus characterized by that.