Information
-
Patent Grant
-
6742356
-
Patent Number
6,742,356
-
Date Filed
Thursday, January 9, 200321 years ago
-
Date Issued
Tuesday, June 1, 200420 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Harness, Dickey & Pierce, PLC
-
CPC
-
US Classifications
Field of Search
US
- 062 500
- 062 512
- 062 116
- 062 503
-
International Classifications
-
Abstract
In a gas-liquid separator for an ejector cycle, a tank body is constructed such that a refrigerant sprayed from a refrigerant inlet forms a spiral stream in the tank body. The tank body has a horizontal longitudinal axis greater than a vertical axis. The refrigerant inlet is located at a distance from the horizontal longitudinal axis of the tank body such that the refrigerant sprayed from the refrigerant inlet generates a turning force and spirally flows. With this, a gas-liquid separation distance of the refrigerant increases.
Description
CROSS REFERENCE TO RELATED APPLICATION
This application is based on Japanese Patent Application No. 2002-3554 filed on Jan. 10, 2002, the disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to a gas-liquid separator for an ejector cycle.
BACKGROUND OF THE INVENTION
In an ejector cycle, which is a kind of a vapor compression refrigerating cycles, an ejector draws gas refrigerant from an evaporator by compressing and expanding refrigerant. Further, the ejector increases pressure of refrigerant that is to be sucked into a compressor by converting expansion energy into pressure energy, in order to decrease a power consumption of the compressor.
The refrigerant discharged in the ejector flows into a tank body of a gas-liquid separator. The gas-liquid separator
50
separates the refrigerant into gas refrigerant and liquid refrigerant by using differences of densities, that is, differences of gravities exerting on the liquid refrigerant and the gas refrigerant. In the tank body, there are a mixed refrigerant region where gas-liquid refrigerant from the ejector exists and a separated refrigerant region where completely separated refrigerant exists. The mixed refrigerant region is located in a top of the tank body and the separated refrigerant region is located in a bottom of the tank body.
Because it is preferable to increase a refrigerant stream distance from the mixed refrigerant region to the separated refrigerant region, a lateral-type tank body which vertical length is greater than a horizontal length is generally used for the separator. Here, the refrigerant stream distance is not a shortest distance between the mixed refrigerant region and the separated refrigerant region, but is the distance that the refrigerant flows to be separated into gas refrigerant and liquid refrigerant. Hereinafter, this refrigerant stream distance is referred to as a gas-liquid separation distance.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a gas-liquid separator that increases a gas-liquid separation distance of refrigerant.
It is another object of the present invention to provide a gas-liquid separator decreased in height.
In a gas-liquid separator for an ejector cycle that includes an ejector for drawing a gas refrigerant from an evaporator and increasing a pressure of refrigerant to be sucked into a compressor, a refrigerant is flowed into a tank body from the ejector and separated into a gas refrigerant and a liquid refrigerant in the tank body. The gas refrigerant is discharged from a gas refrigerant outlet toward the compressor. The liquid refrigerant is discharged from a liquid refrigerant outlet toward the evaporator. The tank body defines a refrigerant inlet through which the refrigerant is discharged into the tank body. The tank body is constructed such that the refrigerant spirally flows in the tank body.
Since the refrigerant forms a spiral stream in the tank body, a gas-liquid separation distance increases. Therefore, even in a horizontal-type tank body, the refrigerant is adequately separated into liquid refrigerant and gas refrigerant.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings, in which:
FIG. 1A
is a schematic illustration of a showcase having a gas-liquid separator according to embodiments of the present invention;
FIG. 1B
is a top view of the bottom of the showcase in
FIG. 1A
;
FIG. 2
is a schematic diagram of an ejector cycle according to the embodiments of the present invention;
FIG. 3
is a schematic illustration of an ejector, partially includes cross-section, according to the embodiments of the present invention;
FIG. 4A
is a schematic illustration of a gas-liquid separator, viewed from a side, according to the first embodiment of the present invention;
FIG. 4B
is a schematic illustration of the gas-liquid separator, viewed from a top, according to the first embodiment of the present invention;
FIG. 4C
is a schematic illustration of the gas-liquid separator, viewed from an end, according to the first embodiment of the present invention;
FIG. 5
is a schematic illustration of the gas-liquid separator according to the second embodiment of the present invention;
FIG. 6
is a schematic illustration of the gas-liquid separator according to the third embodiment of the present invention; and
FIG. 7
is a schematic illustration of the gas-liquid separator according to the fourth embodiment of the present invention.
DETAILED DESCRIPTION OF EMBODIMENTS
The first embodiment will be described hereinafter with reference to
FIGS. 1 through 4C
.
As shown in
FIGS. 1A and 1B
, a gas-liquid separator
50
is applied to an ejector cycle for a showcase
1
that stores food at low temperatures, for example. An evaporator
30
and a blower
2
are provided at the bottom of the showcase
1
.
FIG. 2
is a schematic diagram of the ejector cycle. A compressor
10
is electrically driven. The compressor
10
sucks and compresses refrigerant. A radiator
20
is a high pressure side heat exchanger. The radiator
20
performs heat-exchange between a high temperature, high pressure refrigerant discharged from the compressor
10
and outside air, to cool the refrigerant.
Here, flon is used as the refrigerant. The pressure of the refrigerant on the high pressure side is lower than a critical pressure of the refrigerant. Thus, the refrigerant is condensed in the radiator
20
.
The evaporator
30
is a low pressure side heat exchanger for improving refrigerating capability. The evaporator
30
performs heat exchange between air to be blown into the showcase
1
and liquid refrigerant, and evaporates the liquid refrigerant. The ejector
40
sucks the gas refrigerant evaporated in the evaporator
30
by decompressing and expanding the refrigerant discharged from the radiator
20
. Further, the ejector
40
converts expansion energy into pressure energy to increase pressure of the refrigerant to be sucked into the compressor
10
.
The ejector
40
includes a nozzle
41
, a mixing portion
42
, a diffuser
43
and the like, as shown in FIG.
3
. The nozzle
41
decompresses and expands the refrigerant by converting the pressure energy of the high pressure refrigerant discharged from the radiator
20
into speed energy. The mixing portion
42
sucks the gas refrigerant evaporated in the evaporator
30
by a high-speed flow of the refrigerant jetted from the nozzle
41
. The diffuser
43
increases pressure of the refrigerant by converting speed energy into pressure energy while mixing the refrigerant jetted from the nozzle
41
and the refrigerant sucked from the evaporator
30
. The nozzle
41
has a throttle portion
41
a
at which a passage cross-sectional area, that is, an inner diameter, is minimized. The nozzle
41
is a divergent nozzle such that its inner diameter increases toward the mixing portion
42
from the throttle portion
41
a.
In the mixing portion
42
, the refrigerant jetted from nozzle
41
mixes with the refrigerant sucked from the evaporator
30
such that the sum of momentum of those refrigerants is maintained. Therefore, the pressure of the refrigerant increases in the mixing portion
42
. In the diffuser
43
, an inner diameter gradually increases toward its end (to right side in
FIG. 3
) so that the speed energy of the refrigerant is converted into the pressure energy. Therefore, the pressure of the refrigerant increases in the mixing portion
42
and the diffuser
43
. Here, the mixing portion
42
and the diffuser
43
are referred to as a pressure increase portion.
The refrigerant discharged in the ejector
40
flows into the gas-liquid separator
50
, as shown in FIG.
2
. The gas-liquid separator
50
separates the refrigerant into gas refrigerant and liquid refrigerant and stores the refrigerant. The gas-liquid separator
50
discharges the gas refrigerant toward the compressor
10
and also discharges the liquid refrigerant toward the evaporator
30
.
Referring to
FIGS. 4A
to
4
C, the gas-liquid separator
50
has a tank body
51
, a refrigerant inlet
52
, a gas refrigerant outlet
53
, a liquid refrigerant outlet
54
and an oil return port
55
. The tank
51
has a substantially cylindrical shape and its ends are closed with spherical surfaces. The refrigerant flows into the tank body
51
through the refrigerant inlet
52
. The gas refrigerant is discharged out from the gas refrigerant outlet
53
toward the compressor
10
. The liquid refrigerant is discharged out from the liquid refrigerant outlet
54
toward the evaporator
10
. The liquid refrigerant including refrigeration oil returns to the compressor
10
from the oil return portion
55
.
The tank body
51
is a horizontal-type pressure vessel such that a horizontal length W is equal to or greater than a vertical length (height) H. The tank body
51
is made of metal having a high corrosion resistance, such as stainless. The tank body
51
is constructed such that the refrigerant spirally flows in the tank body
51
, as shown in FIG.
4
A.
Specifically, the refrigerant inlet
52
is located off center of the tank body
51
, as shown in FIG.
4
C. That is, the refrigerant inlet
52
is located at a distance from a horizontal longitudinal axis of the tank body
51
, so that the refrigerant sprayed from the refrigerant inlet
52
flows toward the longitudinal axis of the tank body
51
and causes a turning force. Further, the refrigerant inlet
52
is directed such that an axis of the refrigerant spray direction from the refrigerant inlet
52
crosses an inner wall of the tank body
51
at an obtuse angle.
The end surface
51
a
of the tank body
51
is domed outward. With this, the axis of the refrigerant spray direction crosses the end surface
51
a
at an obtuse angle. Also, the domed end surface improves a pressure resistance of the tank body
51
.
A partition wall
56
is arranged in the tank body
51
above a liquid level for dividing the tank space into a gas refrigerant space and a liquid refrigerant space. The partition wall
56
prevents the liquid refrigerant from remixing with the gas refrigerant.
The partition wall
56
does not completely divide the tank space, but communication spaces
56
a
remains between the partition wall
56
and the inner wall of the tank body
51
to allow communication between the gas refrigerant space and the liquid refrigerant space.
The refrigerant inlet
52
and gas refrigerant outlet
53
are located above the partition wall
56
. The liquid refrigerant outlet
54
and oil return port
55
are located below the partition wall
56
. This arrangement restricts the liquid refrigerant surface from being disturbed by the refrigerant sprayed from the refrigerant inlet
52
.
An inlet pipe
52
a
connecting the refrigerant inlet
52
and a refrigerant discharge side of the ejector
40
and an outlet pipe
53
a
connecting the gas refrigerant outlet
53
and the suction side of the compressor
10
are inserted into the tank body
51
through the end surface
51
a
, as shown in
FIGS. 4A and 4B
.
Next, operation of the ejector cycle will be described.
When the compressor
10
starts operation, the compressor
10
draws the gas refrigerant from the gas-liquid separator
50
. The compressor
10
decompresses the refrigerant and discharges it to the radiator
20
. Then, the radiator
20
cools the refrigerant and discharges it to the ejector
40
. The ejector
40
decompresses and expands the refrigerant at the nozzle
41
and draws the gas refrigerant from the evaporator
30
.
The mixing portion
42
mixes the refrigerant from the evaporator
30
and the refrigerant from the nozzle
41
. The diffuser
43
converts dynamic pressure into static pressure. Then, the refrigerant returns to the gas-liquid separator
50
.
When the ejector
40
draws the refrigerant from the evaporator
30
, the liquid refrigerant in the gas-liquid separator
50
is discharged into the evaporator
30
. The refrigerant absorbs heat from the air to be blown into the showcase
1
and evaporates in the evaporator
30
.
The tank body
51
is constructed such that the refrigerant forms a spiral stream. With this, the gas-liquid separation distance, which is the stream length of the refrigerant stream to be separated into gas refrigerant and liquid refrigerant, increases. Therefore, even in the horizontal-type vessel, the refrigerant is adequately separated into the gas refrigerant and the liquid refrigerant. Accordingly, the gas-liquid separator
50
can be mounted in a space where a height is limited, such as in the showcase
1
.
The refrigerant discharged in the tank body
51
tends to expand in all directions. However, since the refrigerant inlet
52
is open at a position separated from the longitudinal axis of the tank body
51
, the refrigerant flows toward the axis of the tank body
51
. At this time, the refrigerant causes the turning force, thereby forming the spiral flow in the tank body
51
.
Also, the refrigerant inlet
52
is directed such that the axis of the refrigerant spray direction crosses the inner wall of the tank body
51
at an obtuse angle. Further, the end surface
51
a
of the tank body
51
is domed. Therefore, the refrigerant discharge stream strikes the inner wall of the tank body
51
, and generates the turning force. Accordingly, the refrigerant stream turns in the tank body
51
.
Because the inlet pipe
52
a
is provided horizontally in the tank body
51
, the refrigerant is sprayed out horizontally from the inlet
52
. Thus, the refrigerant flows spirally about the horizontal axis of the tank body
51
. However, the refrigerant can be sprayed in the vertical direction. Thus, the refrigerant flows spirally about the vertical axis.
The refrigerant discharge side of the ejector
40
connects with the end surface
51
a
of the tank body
51
. That is, the ejector
40
horizontally connects with the tank body
50
. Therefore, the ejector
40
that is relatively long in the horizontal direction can be easily mounted in a space which height is limited, such as in the showcase
1
.
Since the gas-liquid separator
50
has the partition wall
56
, the gas refrigerant is restricted to re-mixing with the liquid refrigerant.
In the second embodiment, the refrigerant outlet
54
is provided to open in the horizontal direction, as shown in FIG.
5
.
In the third embodiment, the ejector
40
is mounted inside of the tank body
51
, as shown in FIG.
6
. Although the ejector
40
is almost enclosed in the tank body
51
in
FIG. 6
, the ejector
40
can be connected such that only a part of the ejector
40
is inside of the tank body
51
. With this arrangement, a mounting space of the ejector
40
decreases.
In the fourth embodiment, the tank body
51
has two different tank rooms
51
b
,
51
c
, as shown in FIG.
7
. That is, the tank body
51
has a gas refrigerant room
51
b
and a liquid refrigerant room
51
c
, in place of separating the tank space with the partition wall
56
.
In the above embodiments, the gas-liquid separator
50
is applied to the ejector cycle of the showcase
1
. However, the gas-liquid separator
50
of the present invention can be used for other purposes.
Although the refrigerant inlet
52
is arranged above the partition wall
56
, the refrigerant inlet
52
can be arranged below the separation wall
56
, for example. Further, materials, such as carbon dioxide and hydrocarbon, can be used as the refrigerant.
The present invention should not be limited to the disclosed embodiments, but may be implemented in other ways without departing from the spirit of the invention.
Claims
- 1. A gas-liquid separator for an ejector cycle that includes an ejector for drawing gas refrigerant from an evaporator by decompressing refrigerant then increasing pressure of refrigerant to be sucked into a compressor, the gas-liquid separator comprising:a tank body for separating refrigerant into gas refrigerant and liquid refrigerant, the tank body defining a refrigerant inlet through which the refrigerant is discharged into the tank body from the ejector, a gas refrigerant outlet through which the gas refrigerant is discharged toward the compressor and a liquid refrigerant outlet through which the liquid refrigerant is discharged toward the evaporator, wherein: the tank body has a horizontal axis longer than a vertical axis; and the tank body is constructed such that the refrigerant flows spirally about the horizontal axis throughout the tank body.
- 2. The gas-liquid separator according to claim 1, wherein the refrigerant inlet is located at a distance from a horizontal, longitudinal axis of the tank body.
- 3. The gas-liquid separator according to claim 1, wherein the tank body connects with the ejector in a horizontal direction.
- 4. The gas-liquid separator according to claim 1, wherein the tank body connects with the ejector such that at least a part of the ejector is located in the tank body.
- 5. The gas-liquid separator according to claim 1,wherein the tank body includes a partition wall for dividing a tank space into a gas refrigerant space and a liquid refrigerant space, wherein the partition wall is located above a liquid level of the liquid refrigerant.
- 6. The gas-liquid separator according to claim 1, wherein the refrigerant inlet is directed such that an axis of the refrigerant discharge direction from the refrigerant inlet crosses an inner wall of the tank body at an obtuse angle.
- 7. The gas-liquid separator according to claim 1, wherein the tank body defines a curved inner wall such that the refrigerant discharged from the refrigerant inlet strikes the curved inner wall at an obtuse angle.
- 8. A gas-liquid separator for an ejector cycle including an ejector, the gas-liquid separator comprising:a tank body for separating refrigerant into gas refrigerant and liquid refrigerant, the tank body including a substantially cylindrical wall portion having a horizontal longitudinal axis and first and second end surfaces, and the tank body defining a gas refrigerant outlet through which the gas refrigerant flows out of the tank body and a liquid refrigerant outlet through which the liquid refrigerant flows out of the tank body; and a refrigerant inlet pipe communicating the tank body with the ejector, wherein the refrigerant inlet pipe defines a refrigerant opening at its end, the refrigerant opening being opened inside the tank body such that refrigerant discharged from the opening is sprayed to form a spiral stream about the horizontal longitudinal axis throughout the tank body.
- 9. The gas-liquid separator according to claim 8, wherein the refrigerant opening is located at a distance from the horizontal longitudinal axis of the tank body.
- 10. The gas-liquid separator according to claim 8, wherein the horizontal longitudinal axis of the tank body is longer than a vertical axis of the tank body.
- 11. The gas-liquid separator according to claim 8, further comprising:a partition wall separating a tank space into a liquid refrigerant space and a gas refrigerant space, wherein the partition wall is placed horizontally above a liquid level.
- 12. The gas-liquid separator according to claim 8, wherein the refrigerant opening is directed such that an axis of a refrigerant spray direction crosses an inner wall of the tank body at an obtuse angle.
- 13. The gas-liquid separator according to claim 8, wherein the refrigerant inlet pipe horizontally passes through the first end surface of the tank body.
- 14. The gas-liquid separator according to claim 8, wherein the ejector is connected to the first end surface of the tank body.
- 15. The gas-liquid separator according to claim 8, wherein the second end surface of the tank body is curved such that a refrigerant stream sprayed from the refrigerant opening strikes an inner wall of the tank body at an obtuse angle.
- 16. The gas-liquid separator according to claim 2, wherein the gas refrigerant outlet is open in a horizontal direction and is located higher than the refrigerant inlet.
- 17. The gas-liquid separator according to claim 2, wherein the refrigerant inlet and the gas refrigerant outlet are open in horizontal directions.
- 18. The gas-liquid separator according to claim 1, whereinthe tank body has a cylindrical wall having a horizontal longitudinal axis, and a first domed end wall and a second domed end wall at longitudinal ends of the cylindrical wall, the refrigerant inlet is located between the second domed end wall and a middle position of the cylindrical wall with respect to a horizontal direction and opens toward the second domed end wall so that the refrigerant sprayed from the refrigerant inlet strikes the second domed end wall at an obtuse angle, and the gas refrigerant outlet is located proximate to the first domed end wall.
- 19. The gas-liquid separator according to claim 12, wherein the second end surface is in a form of dome and the inner wall is included in the second end surface.
- 20. The gas-liquid separator according to claim 13, wherein the opening of the inlet pipe is open in a horizontal direction and located between the second end surface and a middle position of the tank body with respect to the horizontal direction.
- 21. The gas-liquid separator according to claim 20, wherein the gas refrigerant outlet is located proximate to the first end surface.
- 22. The gas-liquid separator according to claim 21, wherein the liquid refrigerant outlet is located between the first end surface and the middle position of the tank body with respect to the horizontal direction.
- 23. The gas-liquid separator according to claim 14, wherein the ejector is horizontally disposed in the tank body and connects to the inlet pipe on a side opposite to the opening, and the opening is located between the second end surface and a middle position of the tank body with respect to a horizontal direction.
- 24. The gas-liquid separator according to claim 23, wherein the gas refrigerant outlet is located between the first end surface and the middle position of the tank body with respect to the horizontal direction.
- 25. A gas-liquid separator for an ejector cycle that includes an ejector for drawing gas refrigerant from an evaporator by decompressing refrigerant, the gas-liquid separator comprising:a tank body for separating refrigerant into gas refrigerant and liquid refrigerant, the tank body defining a refrigerant inlet through which the gas refrigerant and the liquid refrigerant are discharged into the tank body from the ejector, a gas refrigerant outlet through which the gas refrigerant is discharged toward the compressor and a liquid refrigerant outlet through which the liquid refrigerant is discharged toward the evaporator, wherein the tank body is constructed such that the gas refrigerant and the liquid refrigerant flow throughout the tank body.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2002-003554 |
Jan 2002 |
JP |
|
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JP |
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Jun 1993 |
JP |
6-206438 |
Jul 1994 |
JP |
9-250848 |
Sep 1997 |
JP |
10-267472 |
Oct 1998 |
JP |
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May 1999 |
JP |