JPH11241693A - Compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compressor reducing pressure loss by shortening a refrigerant path in a compressor performing multistage compression for refrigerant by using a plurality of compression parts. SOLUTION: An intermediate partition plate 8 is provided between a first cylinder 9 constituting a low stage side compression part 52 at the inside and a second cylinder 10 constituting a high stage side compression part 51 at the inside. The first cylinder 9 is provided with a discharge port 29. The second cylinder 10 is provided with a suction port 31. On the intermediate partition plate 8, a coolant path communicating the discharge port 29 of the first cylinder 9 and the suction port 31 of the second cylinder 10 is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor that uses a low-stage compression section and a high-stage compression section to sequentially compress refrigerant in multiple stages.

[0002]

2. Description of the Related Art Conventionally, refrigeration systems used in refrigerators, air conditioners, and the like include rotary cylinders and rollers rotating inside the cylinders, respectively, as disclosed in Japanese Patent Publication No. 7-30743 (F04C23 / 00). The rotary type compressor which accommodated two compression parts consisting of the same in the same closed container is adopted. Then, each compression section of the compressor is made into a low-stage compression section and a high-stage compression section, and the refrigerant gas compressed in one stage by the low-stage compression section is sucked into the high-stage compression section, thereby compressing the refrigerant in multiple stages. It was configured as follows.

[0003] The use of such a compressor has the advantage that a high compression ratio can be obtained while suppressing the torque fluctuation per compression.

[0004]

However, when the refrigerant is multi-stage compressed by the above-described compressor, the refrigerant compressed by the low-stage compression section passes through the pipe mounted outside the closed vessel to the high-stage side. It was guided to the suction port of the compression section. For this reason, there has been a problem that the refrigerant passage becomes long and the pressure loss increases.

The present invention has been made to solve the above-mentioned conventional technical problem, and an object of the present invention is to reduce a pressure loss in a compressor that compresses a refrigerant in multiple stages by using a plurality of compression units. And

[0006]

That is, a compressor according to the present invention includes an electric motor and a compression element driven by the electric motor in a single hermetic container. And a multistage compression unit for sequentially compressing the refrigerant in multiple stages, wherein a first cylinder constituting the low stage compression unit inside and a second cylinder constituting the high stage compression unit inside Cylinder, an intermediate partition plate disposed between these two cylinders, a discharge port formed in the first cylinder, a suction port formed in the second cylinder, and a second partition formed in the intermediate partition plate. It is provided with a passage communicating the discharge port of one cylinder and the suction port of the second cylinder.

[0007]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a refrigerant circuit diagram of a multistage compression refrigerating apparatus R to which a rotary compressor C according to the present invention is applied, FIG. 2 is a longitudinal sectional side view of the compressor C of the present invention, and FIG. FIG. 4 is an enlarged view of the refrigerant passage.

First, in FIG. 2, 1 is a closed container,
An electric motor (brushless DC motor) 2 is accommodated in the upper part of the inside, and a compression element 3 driven to rotate by the electric motor 2 is accommodated in the lower part. The airtight container 1 contains the electric motor 2 and the compression element 3 in a preliminarily divided into two parts and is sealed by high frequency welding or the like.

The electric motor 2 includes a stator 4 fixed to the inner wall of the closed casing 1 and a rotor 5 supported inside the stator 4 so as to be rotatable around a rotation shaft 6. . The stator 4 includes a stator winding 7 that applies a rotating magnetic field to the rotor 5. W1 and W2 are balance weights attached to the upper and lower surfaces of the rotor 5, respectively.

The compression element 3 has a first rotary cylinder 9 and a second rotary cylinder 10 partitioned by an intermediate partition plate 8 described later. Each cylinder 9, 1
The eccentric portions 11 and 12 that are driven to rotate by the rotation shaft 6 are attached to the axis 0, and the eccentric portions 11 and 12 are attached with their eccentric positions shifted by 180 degrees from each other.

Reference numerals 13 and 14 denote a first roller and a second roller which rotate in the cylinders 9 and 10, respectively, and rotate in the cylinder by rotation of the eccentric portions 11 and 12, respectively. 15,
Reference numeral 16 denotes a first frame and a second frame, respectively. The first frame 15 forms a closed compression space of the cylinder 9 between the first frame 15 and the intermediate partition plate 8, and the second frame 16 is Similarly, a closed compression space of the cylinder 10 is formed between the cylinder 10 and the intermediate partition plate 8. The first frame 15 and the second frame 16 are respectively provided with bearing portions 17, 1 that rotatably support the lower portion of the rotary shaft 6.
8 is provided.

The upper cylinder 9, the eccentric portion 11, the roller 13, the vanes (not shown) for dividing the inside of the cylinder 9 into a high-pressure chamber and a low-pressure chamber, and the like constitute a high-stage compression section 51. Cylinder 10, eccentric part 12, roller 14
And a vane (not shown) that partitions the inside of the cylinder 10 into a high-pressure chamber and a low-pressure chamber, and the like, and the low-stage compression section 52 is configured.

The intermediate partition plate 8 is composed of an upper intermediate partition plate 8A and a lower intermediate partition plate 8B. The upper intermediate partition plate 8A is provided on the high-stage side compression section 51 side, and the lower intermediate partition plate 8A. 8B is provided on the low-stage compression section 52 side. The upper intermediate partition plate 8A is configured to have a small thickness, and a through hole 8AA having a predetermined size is provided in the vicinity of the outer periphery so as to penetrate in the thickness direction (FIGS. 7 and 8).

The lower intermediate partition plate 8B is connected to the upper intermediate partition plate 8B.
A is configured to be thicker than A, and a refrigerant passage 8BB penetrating in the thickness direction is provided near the outer periphery. The coolant passage 8BB is provided to extend a predetermined distance in the circumferential direction, and is provided at a position corresponding to the through hole 8AA provided in the upper intermediate partition plate 8A (FIGS. 9 and 10).

Further, a suction port 31 is provided on the upper intermediate partition plate 8A side below the upper cylinder 9;
The suction port 31 is formed corresponding to the through hole 8AA provided in the upper intermediate partition plate 8A. The inside of the upper cylinder 9 is communicated with the through hole 8AA by a suction port 31 (FIGS. 5 and 6).

A discharge port 29 is provided on the lower intermediate partition plate 8B side above the lower cylinder 10, and this discharge port 29 is connected to a refrigerant passage 8BB provided in the lower intermediate partition plate 8B. It is formed correspondingly. The inside of the lower cylinder 10 is communicated with the through hole 8AA by the discharge port 29. A valve 29A is provided on the lower intermediate partition plate 8B side of the cylinder 10.
This valve 29A allows the refrigerant in the cylinder 10 to pass through the refrigerant passage 8
It is configured such that the refrigerant in the refrigerant passage 8BB does not flow into the cylinder 10 while flowing through the BB. 2
9B is a screw for fixing the valve 29A.

That is, the discharge side of the lower cylinder 10 (low-stage compression section 52) and the upper cylinder 9 (high-stage compression section 5).
The suction side 1) includes a discharge port 29, a valve 29A, and a refrigerant passage 8 provided in the lower cylinder 10 as shown in FIG.
BB, the through hole 8AA, and the suction port 31 communicate with each other.

On the other hand, the displacement volume of the low-stage compression section 52 is
1. Assuming that the excluded volume of the high-stage compression section 51 is D2, the excluded volume ratio D2 / D1 is set in the range of 0.35 ± 0.15.

Reference numeral 19 denotes a discharge muffler, and the first frame 1
5 is attached. The cylinder 9 and the discharge muffler 19 communicate with each other through a discharge hole (not shown) provided in the first frame 15.

The second frame 16 has a recess 21 which is closed by a lid 26 and a bolt 27
Is fixed to the cylinder 10 integrally with the second frame 16. The second frame 16 is located at the lowermost part in the closed container 1, and its periphery is an oil reservoir 30 for storing lubricating oil. As a result, the periphery of the second frame 16 is filled with the lubricating oil, thereby preventing a decrease in performance due to a decrease in the amount of circulating refrigerant.

On the other hand, reference numeral 22 denotes a discharge pipe provided on the closed vessel 1, and reference numeral 24 denotes a suction pipe connected to the cylinder 10. Reference numeral 25 denotes a sealed terminal, which is a sealed container 1
To supply electric power to the stator winding 7 of the stator 4 from the outside (not shown are lead wires connecting the sealed terminal 25 and the stator winding 7).

Next, in the refrigerant circuit of FIG. 1, the discharge pipe 22 of the compressor C constituting the multi-stage compression refrigeration system R
It is connected to the inlet of a condenser 37 via a pipe 36, and the outlet of the condenser 37 is connected to a capillary tube 38 as primary expansion means. This capillary tube 38
Is connected to an upper portion of a gas-liquid separator 39, and a capillary tube 41 is connected to a lower end of the gas-liquid separator 39 as secondary expansion means.

A cooler 42 is connected to the outlet of the capillary tube 41, and a pipe 43 connected to the outlet of the cooler 42 is connected to the suction pipe 24 of the compressor C. Further, a pipe 44 is connected to an upper portion of the gas-liquid separator 39, and the pipe 44 communicates from the suction pipe 23 to the suction side of the high-stage compression section 51.

The refrigeration cycle of the multi-stage compression refrigeration system R is configured as described above. And such a multi-stage compression refrigeration system R
A predetermined amount of HFC refrigerant or HC refrigerant such as R-134a is sealed in the refrigerant circuit, and ester oil, mineral oil, or the like is used as a lubricating oil.
a is used as a refrigerant, and ester oil is used as a lubricating oil.

The operation of the above configuration will now be described. When the electric motor 2 is driven, the low-stage compression section 52 sucks the refrigerant from the suction pipe 24 and compresses it (one-stage compression).
From the refrigerant passage 8BB provided in the lower intermediate partition plate 8B via the valve 29A. The one-stage compressed gas refrigerant discharged into the refrigerant passage 8BB passes through the through-hole 8AA provided in the upper intermediate partition plate 8A, from the suction port 31 to the high-stage side compression part 51.
Is sucked. The compressed (two-stage compressed) two-stage compressed gas refrigerant is discharged from the discharge hole to the discharge muffler 19, and discharged from the discharge muffler 19 into the closed container 1.

The two-stage compressed gas refrigerant discharged from the closed container 1 is discharged from the discharge pipe 22 to the pipe 36. And
After flowing into the condenser 37, where the heat is released and condensed, the pressure is reduced by the capillary tube 38. Then, it flows into the gas-liquid separator 39, and a part thereof evaporates there.

Thus, the liquid refrigerant is stored at the bottom of the gas-liquid separator 39, and the one-stage expanded saturated gas refrigerant is stored at the top of the gas-liquid separator 39. At this time, the temperature of the saturated gas refrigerant, that is, the gas-liquid separation temperature is −10 ° C. to + 10 ° C.
The throttle amount of the capillary tube 38 is selected so as to be in the range of 25 ° C.

Then, only the liquid refrigerant flows out of the gas-liquid separator 39 toward the capillary tube 41, where the pressure is reduced. Then, it flows into the cooler 42 and evaporates. At this time, the cooler 42 exerts a cooling action by removing heat from the surroundings. Then, the low-temperature gas refrigerant that has exited the cooler 42 returns to the compressor C via the pipe 43, and is sucked again from the suction pipe 24 into the low-stage compression section 52.

On the other hand, the saturated gas refrigerant in the upper part of the gas-liquid separator 39 flows out to the pipe 44, passes therethrough, is sucked from the suction pipe 23 to the high-stage compression section 51, and is compressed again. The high-stage compression unit 51 merges with the saturated gas refrigerant sucked from the suction pipe 23 and the first-stage compressed gas refrigerant discharged from the low-stage compression unit 52 and from the refrigerant passage 8BB provided in the intermediate partition plate 8 and compressed again. Will be done.

As described above, the low-stage compression section 5 of the compressor C
2. A refrigeration cycle is formed by sequentially connecting the high-stage compression section 51, the condenser 37, the capillary tube 38, the gas-liquid separator 39, the capillary tube 41, and the cooler 42 in a ring shape, and the low-stage compression section 52 The discharged refrigerant is transferred to the refrigerant passage 8.
While being sucked into the high-stage compression section 51 via BB,
Since the saturated gas refrigerant in the gas-liquid separator 39 is sucked into the high-stage compression section 51, the refrigerant passage 8BB can be shortened. This makes it possible to obtain a high compression ratio while suppressing torque fluctuation per compression as compared with a single-stage compression refrigeration system.

Further, the temperature of the gas refrigerant sucked by the high-stage compression section 51 can be reduced, and the input can be reduced. Also, the high-stage compression unit 51
Since the temperature of the discharged gas refrigerant becomes low, even when ester oil is used as the lubricating oil, it is possible to suppress the occurrence of the POE problem and the deterioration of the lubricating characteristics.

Since the liquid refrigerant in the gas-liquid separator 39 flows through the capillary tube 41 and evaporates in the cooler 42, the refrigerating effect on the refrigerant circulation amount is increased, and the efficiency is improved. (See the Mollier diagram in FIG. 13).

Here, the excluded volume D1 of the low-stage compression section 52
The relationship between the coefficient of performance and the ratio D2 / D1 of the excluded volume D2 of the high-stage side compression section 51 and the coefficient of performance is shown in FIG.
The peak characteristic is in the vicinity of (0.3).

Next, the gas-liquid separation temperature in the gas-liquid separator 39 is changed by changing the throttle amount of the capillary tube 38, and the peak values of the curves in FIG. 14 at each gas-liquid separation temperature are connected as shown in FIG. Then, a mountain-like characteristic as shown in FIG. 15 or FIG. 16 is obtained.

That is, based on the relationship between the gas-liquid separation temperature and the coefficient of performance in the gas-liquid separator 39 shown in FIG. 15 or FIG. Is set in the range of −10 ° C. to + 25 ° C., so that the coefficient of performance can be significantly improved as compared with the case of the single-stage compression refrigeration apparatus shown at the bottom of FIG.

As is apparent from FIG.
The coefficient of performance has a peak-like characteristic with a peak around 30% of the excluded volume ratio D2 / D1 of the low-stage compression section 52 and the high-stage compression section 51. In the present invention, the excluded volume ratio D2 /
Since D1 is set in the range of 0.35 ± 0.15, the coefficient of performance can be further improved and efficiency can be improved as compared with a single-stage compression refrigeration system.

The low-stage compression unit 52 and the high-stage compression unit 5
1 is communicated with the refrigerant passage 8BB provided in the intermediate partition plate 8, so that the refrigerant passage between the compression portions 52 and 51 can be shortened, and the pressure loss can be greatly reduced. Become like

In the embodiment, the compressor C of the two-stage compression type has been described. However, the present invention is not limited to this, and the present invention is also effective when applied to a three-stage or four-stage compressor.

[0039]

As described above in detail, according to the present invention, an electric motor and a compression element driven by the electric motor are provided in a single hermetically sealed container, and the compression element is provided with a low-stage compression section. In a compressor configured by a high-stage compression section and sequentially compressing the refrigerant in multiple stages, a first cylinder that internally configures a low-stage compression section, and a second cylinder that internally configures a high-stage compression section. An intermediate partition plate disposed between these two cylinders, a discharge port formed in the first cylinder, and a suction port formed in the second cylinder. A passage communicating with the discharge port of the second cylinder and the suction port of the second cylinder is formed, so that the refrigerant compressed at the low-stage compression section and discharged from the discharge port passes through the passage of the intermediate partition plate at the high stage. It is guided by the suction port of the side compression section.

That is, since the intermediate partition plate for partitioning between the two cylinders constitutes a refrigerant circuit between the low-stage compression section and the high-stage compression section, compared with a case where special piping is mounted outside the closed vessel. Thus, the refrigerant passage can be shortened, and the pressure loss can be reduced.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram of a multi-stage compression refrigeration apparatus employing a compressor of the present invention.

FIG. 2 is a vertical sectional side view of the compressor of the present invention.

FIG. 3 is an enlarged view of a compression element diagram.

FIG. 4 is an explanatory diagram of a refrigerant passage.

FIG. 5 is a bottom view of the upper cylinder.

FIG. 6 is a sectional view taken along line AA of FIG. 5;

FIG. 7 is a front view of an upper intermediate partition plate.

FIG. 8 is a side view of the intermediate partition plate.

FIG. 9 is a front view of a lower intermediate partition plate.

FIG. 10 is a side view of the lower intermediate partition plate.

FIG. 11 is a top view of the lower cylinder.

FIG. 12 is a sectional view taken along line BB of FIG. 11;

FIG. 13 is a Mollier diagram of the multistage compression refrigeration apparatus of FIG.

FIG. 14 is a diagram showing the relationship between the excluded volume ratio and the coefficient of performance of the low-stage compression unit and the high-stage compression unit.

FIG. 15 is a diagram showing a relationship between a gas-liquid separation temperature and a coefficient of performance in a gas-liquid separator.

FIG. 16 is another diagram showing the relationship between the gas-liquid separation temperature and the coefficient of performance in the gas-liquid separator.

[Explanation of symbols]

 C Compressor R Multi-stage compression refrigeration system 2 Electric motor 3 Compression element 8 Intermediate partition plate 8A Upper intermediate partition plate 8AA Through hole 8B Lower intermediate partition plate 8BB Refrigerant passage 9, 10 Cylinder 13, 14 Roller 29 Discharge port 29A Valve 31 Suction port 37 Condenser 38 Capillary tube 39 Gas-liquid separator 41 Capillary tube 42 Cooler 43 Pipe 44 Pipe 51 High-stage compression unit 52 Low-stage compression unit

Claims (1)

[Claims] An electric motor and a compression element driven by the electric motor are provided in a single closed container.
In a compressor configured by a low-stage compression section and a high-stage compression section and sequentially compressing the refrigerant in multiple stages, a first cylinder that internally configures the low-stage compression section,
A second cylinder that constitutes the high-stage compression section inside,
An intermediate partition plate disposed between these two cylinders, a discharge port formed in the first cylinder, a suction port formed in the second cylinder, and a second port formed in the intermediate partition plate; A compressor comprising a passage communicating between a discharge port of one cylinder and a suction port of the second cylinder.